And, to some degree, it seems, gender-affirming hormone therapy (specifically with testosterone). Two recent publications (here and here) agree that lipid profiles are adversely affected in transgender men taking testosterone, and by extension, calculated cardiovascular risk is also affected. As more evidence accumulates, risk relationships are coming into clearer focus. And risk, it seems, is real.

Gender-affirming care saves lives

But don’t let this deter you: gender-affirming healthcare saves lives. Suicide is a major risk for transgender people. This is on top of the risks associated with lack of access to routine care. Providing safe access to gender-affirming care, including hormone therapy if desired, is a powerful tool that reduces suicide and improves quality of life. And the medical community knows how to mitigate the risk of cardiovascular disease.

Embrace diversity

The transgender and gender-nonconforming population is diverse (and for that reason, I’ll use the term “gender diverse” from here). Some people might use pronouns you’re not familiar with. Some might identify as non-binary or another category you’re not familiar with. Some might be children. Some might be old. They can and do have every comorbidity you can think of, just like everyone else. Of course, this includes the number one killer of US adults: cardiovascular disease. And it’s not always entirely clear what the risk is, given the paucity of evidence about this population (there’s no gender identity data in the Framingham Heart Study, is there?).

Risk reduction in practice

Whether testosterone is prescribed or not, clinicians who care for gender diverse patients need to integrate risk reduction into gender-affirming care in meaningful and robust ways. The conversation cannot stop at “let’s measure lipid levels at baseline and check in every once in a while”. It cannot stop at “we offered tobacco cessation counseling”. It cannot stop at “we discussed the risks and benefits”. We can do more.

Start with access to high-quality care

This is a health equity issue. Medical providers, are you doing your part?

• The most important intervention to improve the health of gender diverse people is to facilitate access to safe, high-quality health care. This includes ensuring that every clinical environment is gender-inclusive and trauma-informed.
• Ensure your patients’ basic needs being met. It’s hard to talk about nutrition and stress reduction if you’re not sure where you’re going to sleep. Ask. And make necessary referrals. This is a powerful step.
• Consider the full spectrum of risk-reduction options — including but not limited to pharmacological approaches? Don’t under-manage risk. And let individual patients’ values and preferences inform treatment decisions. This is the standard of care — are you applying it?

Focus on prevention and wellness

• Focus on prevention. Provide support for lifestyle approaches to risk reduction that meet your gender-diverse patients where they are. Give strong recommendations. Facilitate access to nutrition support, exercise programs, smoking cessation, counseling, or whatever else your patient might need.
• Use the tools available to you — brief motivational interviewing can enable positive change, even in a busy visit.
• Find or develop lists of queer-friendly gyms, coaches, and running or hiking groups in your areas. Exercise is a powerful wellness tool physiologically, psychologically, and socially, but not all spaces and professionals are inclusive.

Use the data for good

We’ll continue to see more evidence about the health of gender-diverse people over the coming years. More research is underway, and research protocols are slowly becoming more nuanced and inclusive. As the evidence matures, we’ll likely see more risk factors emerge. We are responsible for taking this evidence into context and using it to reduce risk — not to create barriers to care.

The post Let’s Improve Cardiovascular Health in Transgender People appeared first on Medika Life.

Afterwards she was fine but two months later, when getting out of bed to go to the bathroom, her heart rate jumped up to about 130 bpm. She laid back down but it persisted. Episodes like this occurred nearly every time she moved about and were very scary. On one occasion her heart rate got up to about 200 bpm. “I thought I was going to die.”

She saw her primary care physician at a time when her heart rate was normal. The physician did a history, exam, electrocardiogram and all was normal. She had no idea of what had happened and had no further suggestions. “If it recurs, come on back.” The symptoms did recur the next day and she went back to see the physician. This time she was sent for a cardiac echo and a CAT scan. Both were normal. [The history of recent Covid-19 should have suggested a Long Covid syndrome such as inappropriate tachycardia syndrome, postural orthostatic tachycardia syndrome (POTS) or some of the other arrhythmia syndromes associated with Long Covid. Unfortunately, relatively few doctors are aware.] The symptoms continued to occur and so she was finally referred to a cardiologist.

The cardiologist, also not familiar with Long Covid cardiac issues, was baffled by the symptoms and had her wear a Holter monitor (this device records the electrocardiogram continuously over a day or more) during the weekend. She returned on Monday and was told that she would hear the results within 24 hours. But despite frequent calls to the office, she didn’t hear for almost 10 days.

When finally called, it was a different doctor who said that on one occasion her heart rate had jumped up to 170 bpm and “this is very concerning.” She said “Yes, I agree. I know because I took my pulse then.” The cardiologist had no particular suggestions and was completely unaware of cardiac issues post Covid despite the fact that the patient had brought in references.

She is now seeing a specialist in Long Covid syndromes and who is quite competent in dealing with heart and vascular problems after Covid.

As outlined in my previous article, Long Covid occurs in 10 to 30% of individuals with mild Covid-19 infection. Some of these people develop various cardiovascular symptoms. I want to emphasize here that I am not referring to patients who have had severe Covid-19 with hospitalization and perhaps ventilator support. Instead, the focus is on individuals with mild Covid. As you will see, these individuals can develop various heart and blood vessel syndromes that can range from asymptomatic, to minor annoyances to quite severe, to death.

Heart damage is just one more aspect of Long Covid. It is known that the coronavirus can infect the cells of all three layers of the heart plus the outer lining of the heart, the pericardium. Coronavirus also infects the endothelial (lining) cells of the coronary arteries and other blood vessels. So there’s plenty of opportunity for the coronavirus to cause some level of damage to the heart and blood vessels. It also can attack the nervous system either directly or via autoantibodies.

It is a concern that this damage is occurring or can occur in young previously very healthy individuals. They are just the ones that typically have mild disease or asymptomatic infection. Fairly early in the pandemic there was a study of 26 college competitive athletes who had tested positive for Covid-19. Most of them were asymptomatic and none were hospitalized. Yet on MRI, 12 to 53 days following their initial diagnosis, 46% demonstrated evidence of myocarditis (inflammation of the heart muscle cells) or other cardiac injury. This was a wakeup call that even those who had mild disease could have some form of heart damage including those who were very healthy and young.

The question is — will the pandemic result in many individuals with damaged hearts, individuals that will need long term care?

My friend Eleanor in the opening story above has post exertion tachycardia or a related arrhythmia syndrome.

POTS has been known to be a rare syndrome since long before the pandemic. Most affected individuals, usually young women, report a “viral illness” that preceded onset. POTS can have associated fatigue and brain fog, memory difficulty and headaches, even nausea and vomiting. It is a form of “dysautonomia” that occurs in an estimated one to three million Americans. Dysautonomia refers to an imbalance in the autonomic nervous system, the sympathetic and parasympathetic systems that control heart rate, breathing, GI motility, blood pressure and other automatic functions of the body. Just what causes this imbalance is unclear.

Now POTS is being seen in increased numbers after mild Covid. Certainly not common but very disabling.

Inappropriate tachycardia syndromes including post exertion are being recognized with increasing regularity, sufficient that the term has been suggested as a distinct group of syndromes following Covid-19.

There is evidence that the vagus nerve, the long nerve that operates the parasympathetic system, is damaged by the coronavirus. This damage may be in part the cause of fatigue and other generalized symptoms. But there is also evidence that the tiny nerve endings throughout the body are damaged. Those that surround blood vessels can result in an inability of the smooth muscles around these vessels to contract normally and hence impacting blood pressure. It is likely that this damage is not directly from the virus. Rather, evidence points to the development of autoantibodies that damage nerve endings.

The patient’s history is the key to diagnosis of POTS but the confirmatory test is to lie flat for five minutes, then stand and compare the pulse before and after. If it rises by more than 30 bpm, the diagnosis is confirmed. In some individuals with POTS, the pulse will continue to rise even further over the next 5–10 minutes. Normally, the pulse should increase minimally after arising and then subside within a few minutes at most.

Pre-pandemic, doctors found that POTS could persist for long time frames or subside over weeks to months yet reoccur months later in some. It can be a lifetime of waxing and waning of varying severity. There is no cure. The usual treatment is to drink plenty of fluids, eat a salty diet, and wear full-length compression stockings. These can help but not fully alleviate the symptoms. It appears that post Covid POTS follows the same patterns.

One study of 20 patients, mostly female, with autonomic dysfunction after Covid-19 found (see image) that 6- eight months after diagnosis, 60% could not return to work, 25% could work with accommodations and the remainder were able to eventually return to work.

A series of 27 post Covid patients referred to the Mayo Clinic found a spectrum of autonomic dysfunction after Covid-19 including POTS, lightheadedness, fainting, headache on standing, excessive sweating and burning pains.

Inappropriate tachycardia syndromes including post exertion tachycardia and POTS are not common after Covid-19 but they occur enough that given some 80 million cases in America so far, there are or will be a vast number of individuals with inappropriate tachycardia syndromes and other autonomic disturbances seeking care. As noted above, most doctors including most cardiologists do not seem to be aware.

A major report of heart damage from the Veteran’s Affairs was published in early February, 2022. Epidemiologists looked at the long-term cardiovascular outcomes of individuals seen at any VA health setting during the first 10 ½ months of the pandemic. Using Veterans Affairs electronic health databases, the investigators found 153,760 individuals who had tested positive for COVID-19. Essentially none had received a vaccine as they were not yet available. There were also about 5.5 million during that time who never had a positive test who served as a concurrent control group. They also looked at another 5 ½ million veterans who visited the VA in the year before the pandemic — the historical control group.

The Covid positive individuals were evaluated for cardiovascular outcomes from 30 days after the positive test until 12 months later. They found a substantial number of individuals with cardiovascular disease such as irregularity of the heartbeat, damaged heart muscle, angina and heart attacks, heart failure, and various blood clotting problems, including strokes. The frequency of these diagnoses was compared to the two control groups to determine if they were occurring at the same or greater frequency, i.e., the controls represented the “expected” frequency among these veterans.

Covid-19 positive patients were divided into those never hospitalized for Covid, those hospitalized, and those requiring ICU care.

Those with severe Covid had many cases of persisting or new cardiovascular disorders. But what was more interesting were those with mild Covid who, although having many fewer episodes, the number of cases was very real. It boils down to about 20 more cases per thousand then would be expected based on the control groups.

The authors observe that Covid was “an equal opportunity offender” meaning that the risk was the same for old versus young, diabetes or not, obesity or not, and smoker or not.

It is important to note that these veterans do not represent a full cross section of Americans as they were mostly older white males.

So yes, the risk of cardiovascular disease for a non-hospitalized individual with mild Covid-19 is relatively low but can be a very serious problem for a substantial number of people. In this article I have noted damage to heart muscle from asymptomatic and mild Covid-19 in young healthy college students; autonomic dysfunction with inappropriate tachycardias and POTS after mild Covid; and more serious cardiovascular diseases also after mild Covid.

The total known number of COVID-19 infected people in United States is nearing 80 million. This implies a huge number of individuals with mild Covid will develop autonomic dysfunction like inappropriate tachycardias and multiple cardiovascular diseases during the first year after infection. This is sobering.

Please join me next time for a discussion of mental health/neuro-psychiatric syndromes after mild Covid-19.

The post Cardiovascular Disease Even After Mild COVID-19 Is Real appeared first on Medika Life.

Layers of the Heart Wall

Three layers of tissue form the heart wall. The outer layer of the heart wall is the epicardium, the middle layer is the myocardium, and the inner layer is the endocardium.

Chambers of the Heart

The internal cavity of the heart is divided into four chambers:

• Right atrium
• Right ventricle
• Left atrium
• Left ventricle

The two atria are thin-walled chambers that receive blood from the veins. The two ventricles are thick-walled chambers that forcefully pump blood out of the heart. Differences in thickness of the heart chamber walls are due to variations in the amount of myocardium present, which reflects the amount of force each chamber is required to generate.

The right atrium receives deoxygenated blood from systemic veins; the left atrium receives oxygenated blood from the pulmonary veins.

Valves of the Heart

Pumps need a set of valves to keep the fluid flowing in one direction and the heart is no exception. The heart has two types of valves that keep the blood flowing in the correct direction. The valves between the atria and ventricles are called atrioventricular valves (also called cuspid valves), while those at the bases of the large vessels leaving the ventricles are called semilunar valves.

The right atrioventricular valve is the tricuspid valve. The left atrioventricular valve is the bicuspid, or mitral, valve. The valve between the right ventricle and pulmonary trunk is the pulmonary semilunar valve. The valve between the left ventricle and the aorta is the aortic semilunar valve.

When the ventricles contract, atrioventricular valves close to prevent blood from flowing back into the atria. When the ventricles relax, semilunar valves close to prevent blood from flowing back into the ventricles.

Pathway of Blood through the Heart

While it is convenient to describe the flow of blood through the right side of the heart and then through the left side, it is important to realize that both atria and ventricles contract at the same time. The heart works as two pumps, one on the right and one on the left, working simultaneously. Blood flows from the right atrium to the right ventricle, and then is pumped to the lungs to receive oxygen. From the lungs, the blood flows to the left atrium, then to the left ventricle. From there it is pumped to the systemic circulation.

Blood Supply to the Myocardium

The myocardium of the heart wall is a working muscle that needs a continuous supply of oxygen and nutrients to function efficiently. For this reason, cardiac muscle has an extensive network of blood vessels to bring oxygen to the contracting cells and to remove waste products.

The right and left coronary arteries, branches of the ascending aorta, supply blood to the walls of the myocardium. After blood passes through the capillaries in the myocardium, it enters a system of cardiac (coronary) veins. Most of the cardiac veins drain into the coronary sinus, which opens into the right atrium.

Physiology of the Heart

The conduction system includes several components. The first part of the conduction system is the sinoatrial node . Without any neural stimulation, the sinoatrial node rhythmically initiates impulses 70 to 80 times per minute. Because it establishes the basic rhythm of the heartbeat, it is called the pacemaker of the heart. Other parts of the conduction system include the atrioventricular node, atrioventricular bundle, bundle branches, and conduction myofibers. All of these components coordinate the contraction and relaxation of the heart chambers.

Cardiac Cycle

The cardiac cycle refers to the alternating contraction and relaxation of the myocardium in the walls of the heart chambers, coordinated by the conduction system, during one heartbeat. Systole is the contraction phase of the cardiac cycle, and diastole is the relaxation phase. At a normal heart rate, one cardiac cycle lasts for 0.8 second.

Heart Sounds

The sounds associated with the heartbeat are due to vibrations in the tissues and blood caused by closure of the valves. Abnormal heart sounds are called murmurs.

Heart Rate

The sinoatrial node, acting alone, produces a constant rhythmic heart rate. Regulating factors are reliant on the atrioventricular node to increase or decrease the heart rate to adjust cardiac output to meet the changing needs of the body. Most changes in the heart rate are mediated through the cardiac center in the medulla oblongata of the brain. The center has both sympathetic and parasympathetic components that adjust the heart rate to meet the changing needs of the body.

Peripheral factors such as emotions, ion concentrations, and body temperature may affect heart rate. These are usually mediated through the cardiac center.

The post The Heart appeared first on Medika Life.

Without blood, the human body would stop working.

Blood is a specialized body fluid. It has four main components: plasma, red blood cells, white blood cells, and platelets. Blood has many different functions, including:

• transporting oxygen and nutrients to the lungs and tissues
• forming blood clots to prevent excess blood loss
• carrying cells and antibodies that fight infection
• bringing waste products to the kidneys and liver, which filter and clean the blood
• regulating body temperature

The blood that runs through the veins, arteries, and capillaries is known as whole blood, a mixture of about 55 percent plasma and 45 percent blood cells. About 7 to 8 percent of your total body weight is blood. An average-sized man has about 12 pints of blood in his body, and an average-sized woman has about nine pints. 

The Components of Blood and Their Importance

Many people have undergone blood tests or donated blood, but hematology – the study of blood – encompasses much more than this. Doctors who specialize in hematology (hematologists) are leading the many advances being made in the treatment and prevention of blood diseases.

If you or someone you care about is diagnosed with a blood disorder, your primary care physician may refer you to a hematologist for further testing and treatment.

Plasma

The liquid component of blood is called plasma, a mixture of water, sugar, fat, protein, and salts. The main job of the plasma is to transport blood cells throughout your body along with nutrients, waste products, antibodies, clotting proteins, chemical messengers such as hormones, and proteins that help maintain the body’s fluid balance. 

Red Blood Cells (also called erythrocytes or RBCs)

Known for their bright red color, red cells are the most abundant cell in the blood, accounting for about 40 to 45 percent of its volume. The shape of a red blood cell is a biconcave disk with a flattened center – in other words, both faces of the disc have shallow bowl-like indentations (a red blood cell looks like a donut).

Production of red blood cells is controlled by erythropoietin, a hormone produced primarily by the kidneys. Red blood cells start as immature cells in the bone marrow and after approximately seven days of maturation are released into the bloodstream. Unlike many other cells, red blood cells have no nucleus and can easily change shape, helping them fit through the various blood vessels in your body. However, while the lack of a nucleus makes a red blood cell more flexible, it also limits the life of the cell as it travels through the smallest blood vessels, damaging the cell’s membranes and depleting its energy supplies. The red blood cell survives on average only 120 days.

Red cells contain a special protein called hemoglobin, which helps carry oxygen from the lungs to the rest of the body and then returns carbon dioxide from the body to the lungs so it can be exhaled. Blood appears red because of the large number of red blood cells, which get their color from the hemoglobin. The percentage of whole blood volume that is made up of red blood cells is called the hematocrit and is a common measure of red blood cell levels.

White Blood Cells (also called leukocytes)

White blood cells protect the body from infection. They are much fewer in number than red blood cells, accounting for about 1 percent of your blood.

The most common type of white blood cell is the neutrophil, which is the “immediate response” cell and accounts for 55 to 70 percent of the total white blood cell count. Each neutrophil lives less than a day, so your bone marrow must constantly make new neutrophils to maintain protection against infection. Transfusion of neutrophils is generally not effective since they do not remain in the body for very long.

The other major type of white blood cell is a lymphocyte. There are two main populations of these cells. T lymphocytes help regulate the function of other immune cells and directly attack various infected cells and tumors. B lymphocytes make antibodies, which are proteins that specifically target bacteria, viruses, and other foreign materials.

Platelets (also called thrombocytes)

Unlike red and white blood cells, platelets are not actually cells but rather small fragments of cells. Platelets help the blood clotting process (or coagulation) by gathering at the site of an injury, sticking to the lining of the injured blood vessel, and forming a platform on which blood coagulation can occur. This results in the formation of a fibrin clot, which covers the wound and prevents blood from leaking out. Fibrin also forms the initial scaffolding upon which new tissue forms, thus promoting healing.

A higher than normal number of platelets can cause unnecessary clotting, which can lead to strokes and heart attacks; however, thanks to advances made in antiplatelet therapies, there are treatments available to help prevent these potentially fatal events. Conversely, lower than normal counts can lead to extensive bleeding.

Complete Blood Count (CBC)

A complete blood count (CBC) test gives your doctor important information about the types and numbers of cells in your blood, especially the red blood cells and their percentage (hematocrit) or protein content (hemoglobin), white blood cells, and platelets. The results of a CBC may diagnose conditions like anemia, infection, and other disorders. The platelet count and plasma clotting tests (prothombin time, partial thromboplastin time, and thrombin time) may be used to evaluate bleeding and clotting disorders.

Your doctor may also perform a blood smear, which is a way of looking at your blood cells under the microscope. In a normal blood smear, red blood cells will appear as regular, round cells with a pale center. Variations in the size or shape of these cells may suggest a blood disorder.

Where Do Blood Cells Come From?

Blood cells develop from hematopoietic stem cells and are formed in the bone marrow through the highly regulated process of hematopoiesis. Hematopoietic stem cells are capable of transforming into red blood cells, white blood cells, and platelets. These stem cells can be found circulating in the blood and bone marrow in people of all ages, as well as in the umbilical cords of newborn babies. Stem cells from all three sources may be used to treat a variety of diseases, including leukemia, lymphoma, bone marrow failure, and various immune disorders.

The post Blood appeared first on Medika Life.

Arteries

Arteries carry blood away from the heart. Pulmonary arteries transport blood that has a low oxygen content from the right ventricle to the lungs. Systemic arteries transport oxygenated blood from the left ventricle to the body tissues. Blood is pumped from the ventricles into large elastic arteries that branch repeatedly into smaller and smaller arteries until the branching results in microscopic arteries called arterioles. The arterioles play a key role in regulating blood flow into the tissue capillaries. About 10 percent of the total blood volume is in the systemic arterial system at any given time.

The wall of an artery consists of three layers. The innermost layer, the tunica intima (also called tunica interna), is simple squamous epithelium surrounded by a connective tissue basement membrane with elastic fibers. The middle layer, the tunica media, is primarily smooth muscle and is usually the thickest layer. It not only provides support for the vessel but also changes vessel diameter to regulate blood flow and blood pressure. The outermost layer, which attaches the vessel to the surrounding tissue, is the tunica externa or tunica adventitia. This layer is connective tissue with varying amounts of elastic and collagenous fibers. The connective tissue in this layer is quite dense where it is adjacent to the tunic media, but it changes to loose connective tissue near the periphery of the vessel.

Capillaries

Capillaries, the smallest and most numerous of the blood vessels, form the connection between the vessels that carry blood away from the heart (arteries) and the vessels that return blood to the heart (veins). The primary function of capillaries is the exchange of materials between the blood and tissue cells.

Capillary distribution varies with the metabolic activity of body tissues. Tissues such as skeletal muscle, liver, and kidney have extensive capillary networks because they are metabolically active and require an abundant supply of oxygen and nutrients. Other tissues, such as connective tissue, have a less abundant supply of capillaries. The epidermis of the skin and the lens and cornea of the eye completely lack a capillary network. About 5 percent of the total blood volume is in the systemic capillaries at any given time. Another 10 percent is in the lungs.

Smooth muscle cells in the arterioles where they branch to form capillaries regulate blood flow from the arterioles into the capillaries.

Veins

Veins carry blood toward the heart. After blood passes through the capillaries, it enters the smallest veins, called venules. From the venules, it flows into progressively larger and larger veins until it reaches the heart. In the pulmonary circuit, the pulmonary veins transport blood from the lungs to the left atrium of the heart. This blood has a high oxygen content because it has just been oxygenated in the lungs. Systemic veins transport blood from the body tissue to the right atrium of the heart. This blood has a reduced oxygen content because the oxygen has been used for metabolic activities in the tissue cells.

The walls of veins have the same three layers as the arteries. Although all the layers are present, there is less smooth muscle and connective tissue. This makes the walls of veins thinner than those of arteries, which is related to the fact that blood in the veins has less pressure than in the arteries. Because the walls of the veins are thinner and less rigid than arteries, veins can hold more blood. Almost 70 percent of the total blood volume is in the veins at any given time. Medium and large veins have venous valves, similar to the semilunar valves associated with the heart, that help keep the blood flowing toward the heart. Venous valves are especially important in the arms and legs, where they prevent the backflow of blood in response to the pull of gravity.

Physiology of Circulation

Roles of Capillaries

In addition to forming the connection between the arteries and veins, capillaries have a vital role in the exchange of gases, nutrients, and metabolic waste products between the blood and the tissue cells. Substances pass through the capillary wall by diffusion, filtration, and osmosis. Oxygen and carbon dioxide move across the capillary wall by diffusion. Fluid movement across a capillary wall is determined by a combination of hydrostatic and osmotic pressure. The net result of the capillary microcirculation created by hydrostatic and osmotic pressure is that substances leave the blood at one end of the capillary and return at the other end.

Blood Flow

Blood flow refers to the movement of blood through the vessels from arteries to the capillaries and then into the veins. Pressure is a measure of the force that the blood exerts against the vessel walls as it moves the blood through the vessels. Like all fluids, blood flows from a high pressure area to a region with lower pressure. Blood flows in the same direction as the decreasing pressure gradient: arteries to capillaries to veins.

The rate, or velocity, of blood flow varies inversely with the total cross-sectional area of the blood vessels. As the total cross-sectional area of the vessels increases, the velocity of flow decreases. Blood flow is slowest in the capillaries, which allows time for exchange of gases and nutrients.

Resistance is a force that opposes the flow of a fluid. In blood vessels, most of the resistance is due to vessel diameter. As vessel diameter decreases, the resistance increases and blood flow decreases.

Very little pressure remains by the time blood leaves the capillaries and enters the venules. Blood flow through the veins is not the direct result of ventricular contraction. Instead, venous return depends on skeletal muscle action, respiratory movements, and constriction of smooth muscle in venous walls.

Pulse and Blood Pressure

Pulse refers to the rhythmic expansion of an artery that is caused by ejection of blood from the ventricle. It can be felt where an artery is close to the surface and rests on something firm.

In common usage, the term blood pressure refers to arterial blood pressure, the pressure in the aorta and its branches. Systolic pressure is due to ventricular contraction. Diastolic pressure occurs during cardiac relaxation. Pulse pressure is the difference between systolic pressure and diastolic pressure. Blood pressure is measured with a sphygmomanometer and is recorded as the systolic pressure over the diastolic pressure. Four major factors interact to affect blood pressure: cardiac output, blood volume, peripheral resistance, and viscosity. When these factors increase, blood pressure also increases.

Arterial blood pressure is maintained within normal ranges by changes in cardiac output and peripheral resistance. Pressure receptors (barareceptors), located in the walls of the large arteries in the thorax and neck, are important for short-term blood pressure regulation.

Circulatory Pathways

The blood vessels of the body are functionally divided into two distinctive circuits: pulmonary circuit and systemic circuit. The pump for the pulmonary circuit, which circulates blood through the lungs, is the right ventricle. The left ventricle is the pump for the systemic circuit, which provides the blood supply for the tissue cells of the body.

Pulmonary Circuit

Pulmonary circulation transports oxygen-poor blood from the right ventricle to the lungs, where blood picks up a new blood supply. Then it returns the oxygen-rich blood to the left atrium.

Systemic Circuit

The systemic circulation provides the functional blood supply to all body tissue. It carries oxygen and nutrients to the cells and picks up carbon dioxide and waste products. Systemic circulation carries oxygenated blood from the left ventricle, through the arteries, to the capillaries in the tissues of the body. From the tissue capillaries, the deoxygenated blood returns through a system of veins to the right atrium of the heart.

The coronary arteries are the only vessels that branch from the ascending aorta. The brachiocephalic, left common carotid, and left subclavian arteries branch from the aortic arch. Blood supply for the brain is provided by the internal carotid and vertebral arteries. The subclavian arteries provide the blood supply for the upper extremity. The celiac, superior mesenteric, suprarenal, renal, gonadal, and inferior mesenteric arteries branch from the abdominal aorta to supply the abdominal viscera. Lumbar arteries provide blood for the muscles and spinal cord. Branches of the external iliac artery provide the blood supply for the lower extremity. The internal iliac artery supplies the pelvic viscera.

Major Systemic Arteries

All systemic arteries are branches, either directly or indirectly, from the aorta. The aorta ascends from the left ventricle, curves posteriorly and to the left, then descends through the thorax and abdomen. This geography divides the aorta into three portions: ascending aorta, arotic arch, and descending aorta. The descending aorta is further subdivided into the thoracic arota and abdominal aorta.

Major Systemic Veins

After blood delivers oxygen to the tissues and picks up carbon dioxide, it returns to the heart through a system of veins. The capillaries, where the gaseous exchange occurs, merge into venules and these converge to form larger and larger veins until the blood reaches either the superior vena cava or inferior vena cava, which drain into the right atrium.

Fetal Circulation

Most circulatory pathways in a fetus are like those in the adult but there are some notable differences because the lungs, the gastrointestinal tract, and the kidneys are not functioning before birth. The fetus obtains its oxygen and nutrients from the mother and also depends on maternal circulation to carry away the carbon dioxide and waste products.

The umbilical cord contains two umbilical arteries to carry fetal blood to the placenta and one umbilical vein to carry oxygen-and-nutrient-rich blood from the placenta to the fetus. The ductus venosus allows blood to bypass the immature liver in fetal circulation. The foramen ovale and ductus arteriosus are modifications that permit blood to bypass the lungs in fetal circulation.

The post Blood Vessels appeared first on Medika Life.

An aneurysm is a balloon-like bulge in an artery. Arteries are blood vessels that carry blood from your heart to your organs. Aortic aneurysms are aneurysms that occur in the aorta, the main artery carrying oxygen-rich blood to your body. This article focuses on two types of aneurysms that affect the aorta: abdominal and thoracic aortic aneurysms.

The aorta has thick walls that withstand normal blood pressure. However, certain medical problems, genetic conditions, and trauma can damage or weaken these walls. The force of blood pushing against the weakened or injured walls can cause an aneurysm.

An aortic aneurysm can grow large and either rupture or split. A split is called a dissection and, like a rupture, is life-threatening. Early diagnosis and treatment may prevent serious or life-threatening complications. However, aortic aneurysms can develop and grow large before causing any symptoms. Doctors may be able to slow the growth of an aortic aneurysm with medicines or repair it with surgery if it is found before it ruptures or dissects.

There are two types of aortic aneurysm: thoracic aortic aneurysm and abdominal aortic aneurysm. Until recently, it was thought that thoracic aortic aneurysms and abdominal aortic aneurysms were due to the same cause. Now we know that the two types are separate diseases with different risk factors and causes.

Abdominal Aortic Aneurysm (AAA)

The most common place for an aneurysm is the part of the aorta that runs through the abdomen, called the abdominal aorta. The abdominal aorta provides oxygen-rich blood to the tissues and organs of the abdomen and lower limbs.

Thoracic Aortic Aneurysm (TAA)

A thoracic aortic aneurysm is a less common aneurysm that occurs in the chest portion of the aorta, above the diaphragm

Causes of Aortic Aneurysm

Aortic aneurysms are caused by a weakening of the aortic wall due to damage or injury. Many health conditions and lifestyle habits can put you at risk for damage to the aortic wall, including high blood pressure and smoking. A bulge may occur where the wall has been damaged and is weakened. If left untreated, the aortic wall will continue to weaken, and the bulge will grow. If it becomes large enough, the aortic aneurysm may rupture.

Risk Factors- Aortic Aneurysm

You may have an increased risk of developing an aortic aneurysm because of your age, family history, genes, lifestyle habits, medical conditions, or sex.

Age: Your risk for aortic aneurysms goes up as you age. Abdominal aortic aneurysms are most common in adults after age 65.

Family History and Genetics: Several familial or genetic conditions increase your risk for a thoracic aortic aneurysm. These include:

• Ehlers–Danlos syndrome
• Loeys–Dietz syndrome
• Marfan syndrome
• Turner syndrome
• Familial thoracic aortic aneurysms
• Bicuspid aortic valve (BAV), which is an abnormal aortic valve

Abdominal aortic aneurysms also run in families. One in 10 people with abdominal aortic aneurysms have a family history of abdominal aortic aneurysms. The chance of developing an abdominal aortic aneurysm is 1 in 5 for people who have a first degree relative with the condition, which means a parent, brother, sister, or child was affected.

Lifestyle Habits: Some lifestyle habits increase your risk of having an aortic aneurysm. These include:

• Cigarette smoking, which increases your risk for an aortic aneurysm, especially an abdominal aortic aneurysm. If you are a current smoker, an abdominal aortic aneurysm may grow more quickly and be more likely to rupture.
• Using stimulants such as cocaine
• Weight lifting

Medical Conditions: Medical conditions that are risk factors for aortic aneurysms include:

• Aneurysms of blood vessels in other parts of your body
• Chronic obstructive pulmonary disease (COPD)
• Cardiovascular conditions, such as atherosclerosis, ischemic heart disease, and peripheral artery disease
• High blood cholesterol
• High blood pressure, the leading risk factor for thoracic aortic aneurysms but also a risk factor for abdominal aortic aneurysm
• Infection, a risk factor for thoracic aortic aneurysms. Such a case is known as an infective thoracic aortic aneurysm and is usually caused by bacteria.
• Kidney conditions, such as chronic renal insufficiency, chronic kidney disease, and polycystic kidney disease
• Obesity
• Pheochromocytoma, a rare tumor of the adrenal gland that can lead to high blood pressure
• Trauma, such as from car accidents or falls, a risk factor for thoracic aortic aneurysms
• Vasculitis

Sex: Men are more likely than women to develop aortic aneurysms. However, an existing aneurysm is more likely to rupture at a smaller size in women than in men.

Who should be screened for Aortic Aneurysm

Certain groups of people may be screened for a thoracic aortic aneurysm. They include:

• People who have Marfan, Loeys–Dietz, Ehlers–Danlos, or Turner syndrome
• First-degree relatives of people who have a thoracic aortic aneurysm or a bicuspid aortic valve (BAV)–associated thoracic aortic aneurysm
• Relatives of people with familial thoracic aortic aneurysms who also have the genetic mutation

Certain groups of people who may be screened for abdominal aortic aneurysm include:

• Men and women 65 to 75 years old who have ever smoked or who have a first-degree relative who had an abdominal aortic aneurysm
• Men 65 to 75 years old who never smoked but have other risk factors, such as a family history of abdominal aortic aneurysms in any family member, other vascular aneurysms, or coronary heart disease
• Men and women more than 75 years old who are in good health, who have ever smoked, or who have a first-degree relative who had an abdominal aortic aneurysm.
• People who have peripheral artery disease, regardless of age, sex, smoking history, or family history

Signs, Symptoms, and Complications- Aortic Aneurysm

An aortic aneurysm may not cause any signs or symptoms until the aneurysm ruptures or dissects. The types of symptoms that occur before a rupture will depend on the location of the aneurysm and whether it has become large enough to affect other parts of your body. An aneurysm that ruptures or dissects is life-threatening.

Signs and symptoms

If you do have signs and symptoms of an aortic aneurysm, they may include:

• Difficult or painful swallowing if the aneurysm is pushing on your esophagus
• Difficulty breathing if it is pushing on your trachea, or windpipe
• Feeling full after not eating very much
• Hoarseness
• Pain in the neck, jaw, back, chest, abdomen or shoulder, depending on where the aneurysm is located
• Pulsating or throbbing feeling in your abdomen
• Shortness of breath if the aneurysm is pressing on your lung
• Swelling of the face, neck, or arms if the aneurysm is pushing on the superior vena cava. The superior vena cava is the main vein that returns blood from your upper body to your heart.

If you know you have an aortic aneurysm, it is important to know the signs and symptoms of a rupture, since quick treatment may be life-saving. Signs and symptoms of a rupture may include:

• Light-headedness
• Rapid heart rate
• Sudden, severe pain in your abdomen, chest, or back

Complications arising from Aortic Aneurysm

Complications from aortic aneurysms may be life-threatening and may include:

• Aortic dissection, which is a tear in the inner layer of the aortic wall. It causes blood to collect between the inner and middle layers of the aortic wall. This may lead to rupture of the aorta or not enough blood flow to your organs.
• Aortic insufficiency and aortic regurgitation, both of which occur when the aortic valve does not close properly because a nearby section of the aorta is enlarged. This allows some backward flow of blood back into the heart. As a result, your heart must work harder, which may lead to heart failure.
• Aortic rupture, which causes dangerous bleeding inside the body and can lead to shock
• Cardiac tamponade
• Kidney failure from lack of blood flow to the kidneys
• Lack of blood flow to the bowels, which causes inflammation and injury in the large intestine

Diagnosing Aortic Aneurysm

To diagnose an aortic aneurysm, your doctor will do a physical exam and an imaging test to confirm a screening test. An abdominal aortic aneurysm is diagnosed when your abdominal aorta is three centimeters or greater in diameter. The normal diameter of the thoracic aorta depends on your age, your sex, and which part of the thoracic aorta is measured.

Physical exam

During a physical exam, your doctor may do the following to look for an aortic aneurysm:

• Feel your abdomen to see whether an abdominal aortic aneurysm can be felt
• Listen to your heart for a heart murmur, softer heart sounds, or other changes in your blood flow that could be a sign of an aneurysm
• Check your pulse in your arms and legs to see whether it feels weaker than normal
• Look for signs and symptoms of medical conditions that are risk factors for an aortic aneurysm, such as Marfan or Ehlers-Danlos syndromes. This may include looking at your skin, muscles and bones, eyes, head and face, and heart.

Diagnostic tests and procedures

Different types of imaging studies may be used to diagnose your aortic aneurysm. Consider discussing the options with your doctor. Your doctor may order some of the following imaging tests to confirm or diagnose an aortic aneurysm:

• Computed tomography (CT) to provide information about the location, size and shape of an aneurysm. This may be the first test you get if you have sudden back or abdominal pain, if you already know you have an aortic aneurysm, or if your doctor feels a pulsating bulge in your abdomen while examining you. CT can provide information about the entire aorta, but for routine screening other diagnostic tests like echocardiography or ultrasound may be done first.
• Echocardiography to provide information about the size of the aortic aneurysm and about the thoracic aorta, which is close to heart. Other parts of the thoracic aorta are better seen with other imaging studies such as CT or magnetic resonance imaging (MRI).
• MRI to provide information about the size, shape, and location of the aneurysm
• Ultrasound to provide information about the size of the abdominal aortic aneurysm. If you have abdominal or back pain, an ultrasound can check for an abdominal aortic aneurysm or other possible causes of your pain. Once an aortic aneurysm is seen or suspected on ultrasound, you may have a CT scan or an MRI to provide more details about the shape or location of the aneurysm.

Tests for other medical conditions

Some conditions may mimic the symptoms of abdominal aortic aneurysms. To help diagnose an aortic aneurysm, your doctor may need to perform CT or ultrasound tests to find out whether your symptoms may be caused by other medical conditions, including:

• Appendicitis, inflammation of the appendix
• Cholecystitis, inflammation of the gallbladder often caused by gallstones
• Hiatal hernia, in which a small part of your stomach comes through the opening in your diaphragm
• Pancreatitis, inflammation of the pancreas
• Pericardial disorders, conditions that affect the sac that surrounds your heart
• Pulmonary embolism, a type of venous thromboembolism

Treatment- Aortic Aneurysm

Treatment for your aortic aneurysm will depend on its cause, its size and location, and the factors that put you at risk. Small aortic aneurysms may be managed with healthy lifestyle changes or medicine. The goal is to slow the growth of the aneurysm and lower the chance of rupture or dissection. Your doctor may treat other medical conditions that raise your risk for rupture or dissection, such as high blood pressure, coronary heart disease, chronic kidney disease, and high blood cholesterol. Surgery may be recommended to repair large aneurysms.

Healthy lifestyle changes

Your doctor may recommend heart-healthy lifestyle changes, such as the following:

• Quitting smoking to slow the growth of the aneurysm
• Heart-healthy eating to help lower high blood pressure or high blood cholesterol
• Managing stress to help control high blood pressure, especially for thoracic aortic aneurysms. Your doctor may also suggest that you avoid heavy weightlifting and powerful stimulants, such as cocaine.

Medicines

Your doctor may recommend medicines to treat an aortic aneurysm, including:

• Aspirin, especially if you have other cardiovascular risks
• Blood pressure medicines to lower blood pressure, slow down aneurysm growth, and lower the risk of rupture. These medicines include beta blockers, angiotensin-converting enzyme (ACE) inhibitors, and angiotensin receptor blockers (ARBs).
• Statins to control cholesterol levels, and stop or slow the growth of aortic aneurysms

Procedures or surgery

Depending on the cause or size of an aortic aneurysm or how quickly it is growing, your doctor may recommend surgery to repair it. Rupture or dissection of an aneurysm may require immediate surgical repair.

• Open surgical repair is the most common type of surgery. You will be asleep during the procedure. Your surgical team first makes a large incision, or cut, in your abdomen or chest, depending on the location of the aneurysm, then removes the aneurysm and sews a graft in its place. This graft is typically a tube made of leak-proof polyester. Recovery time for open surgical repair is about a month.
• Endovascular aneurysm repair (EVAR) is less invasive than open surgical repair. This is because the surgical cut is smaller, and you usually need less recovery time. EVAR is used to repair abdominal aortic aneurysms more often than to repair thoracic aortic aneurysms. During the procedure, your surgical team makes a small cut, usually in the groin, then guides a stent graft—a tube covered with fabric—through your blood vessels up to the aorta. The stent graft then expands and attaches to the aortic walls. A seal forms between the stent graft and the vessel wall to prevent blood from entering the aortic aneurysm.

Possible surgery-related complications

Complications of both types of aortic aneurysm repair can occur, and they may be life-threatening. These include:

• Bleeding and blood loss
• Blood clots in blood vessels leading to the bowel, kidneys, legs, or in the graft
• Damage to blood vessels or walls of the aorta when placing the stent graft. The stent graft may also move after it is placed.
• Endoleak, which is a blood leak around the stent graft into the aneurysm. Endoleak may cause rupture of the aneurysm if not treated.
• Gastrointestinal bleeding, which rarely occurs if an abnormal connection forms between the aorta and your intestines after the repair. Blood may show up in your stool, or your stool may be black.
• Heart complications such as heart attack or arrhythmia
• Decreased blood flow to the bowels, legs, kidneys or other organs during surgery. This may lead to injury to these organs.
• Infection of the incision or the graft
• Kidney damage
• Spinal cord injury which may cause paralysis
• Stroke

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