Human Physiology HW#2 (Cardiovascular disorders) by Efrain Rivera-Serrano

Hypertension

2025-03-24 18:39:04 UTC

Hypertension is when your blood pressure is to high due to the force/pressure of blood pushing against the walls of your arteries. The force is consistently to high and causes your blood pressure to sit at or above 140/90 instead of a 120/80. At a physiological level, patients who have this condition can have a more enlarged and thickened left ventricle which can cause heart failure. Individuals may also deal with differences in blood flow, vessel wall damages, and abnormal platelet activations due to the heart working harder to pump blood against the increased resistance. In class we talked about the arteries and how they have elastic properties because of the high pressure that they deal with since they are closest to the heart. People with Hypertension can have arterial stiffness which means that the systolic pressure will heighten which will also increase the work of the heart. Also the ability to regulate blood flow will be impacted due to the stiffness. Another impact would be an increase in sympathetic nervous system activity. If hypertension causes the SNS to be more active then the heart will also be more active which will increase blood pressure.

Raynaud's Phenomenon

2025-03-25 00:45:35 UTC

Raynaud's Phenomenon is a condition where a person's fingers or toes change color (usually pale or blue) and feel cold or numb, usually when they are stressed or exposed to cold temperatures. This happens because the blood vessels in those areas get too tight and block blood from getting through.

Normally, your body controls blood flow using the autonomic nervous system. When it's cold, your body tells the blood vessels in your skin to get smaller (called vasoconstriction) so you don't lose heat. But in people with Raynaud's, the blood vessels "overreact" and get too small. This stops blood from reaching the fingers and toes like it should. That's why they turn white or blue and feel cold or numb. When the blood comes back, the fingers or toes may turn red and feel tingly or painful.

In class, we talked about how the ANS controls things that we don't have to think about, like your heartbeat and blood flow. In Raynaud's, the sympathetic branch of the ANS (which responds to stress and cold) is too active and causes the blood vessels to squeeze too much. Another exam topic that Raynaud's relates to is the blood vessels (obviously). Raynaud's is all about how the blood vessels behave. It shows how important it is for blood vessels to open and close properly to keep you body warm and your fingers healthy.

Endocarditis

2025-03-25 00:47:31 UTC

Endocarditis overall is the inflammation of the endocardium, the innermost layer of the heart that acts as a sort of barrier between the heart chambers and the blood stream. Endocarditis normally occurs in people that already have damaged endocardium. With this disease it is caused by disease or infection. Damaged areas of the endocardium allow for bacteria to form colonies in the heart. This bacteria damages the tissue, affecting the heart's ability to use that tissue to effectively contract and relax. When the bacteria forms a colony in the heart they can produce chemicals that break down the heart’s tissue or can alter the valve's ability to function due to making holes in them. Valves can also be damaged or blocked due to the formation of bacterial colonies, commonly on the right side of the heart. Symptoms can vary but include, heart murmurs, fever, red dots on the hand, and this can be life threatening. In class we learned about the endocardium and how it lines the walls of the heart and allows for blood to flow in and out of different chambers when contraction occurs, and with this damaged contraction and blood flow will be disrupted.

Premature Atrial Contractions - PACs

2025-03-25 02:09:44 UTC

Premature atrial contractions are a type of irregular heartbeat that occurs when an extra beat is triggered in the atria of the heart before the next normal beat is due. This early heartbeat originates from a region in the atrium outside the normal pacemaker, also known as the sinoatrial node(SA node). This causes an abnormal electrical impulse. This disrupts the normal sequence of depolarization and repolarization in the heart, causing the irregular heart rhythm. After the early contraction, there is often a pause before the next normal heartbeat, which can cause a feeling of a skipped beat. They are quite common and often occur in healthy individuals without causing any significant problems. Even though they are typically harmless, they can sometimes be linked to underlying heart conditions or could worsen into more serious arrhythmias(problems with your HR). Having to constantly deal with PACs can lead to an increased or irregular heart rate due to the pause. On an ECG, there is a premature P wave that occurs earlier than expected in the normal rhythm cycle. The ventricles would still contract normally, so the QRS complex does not show any differences, as long as the electrical impulse from the SA node reaches the atrioventricular node(AV Node). If the P-wave occurs very early, it may merge with the T-wave of the next beat, causing an abnormal shape on an ECG.

Hypotension

2025-03-25 04:03:41 UTC

Brugada Syndrome

2025-03-25 14:42:52 UTC

Brugada Syndrome is an extremely rare heart condition where the heart has an abnormal ECG pattern known as "Brugada pattern". This condition often causes sudden cardiac death. The Brugada pattern is caused by gene mutations in the heart's sodium channels which causes an imbalance of charges that are responsible for the heart's rhythm. Most people with the condition have no symptoms and receive a diagnosis once a physician looks at an ECG. However, it was noted that some people experience palpitations, fainting, seizures, and sudden cardiac arrest, but these symptoms are seen with other cardiac conditions as well. In terms of class content, we have learned about ECGs and how they show all of the action potentials in the heart through 5 different waves representing different net electrical charges. Specifically, Brugada’s pattern is described as “a characteristic "coved" or "saddleback" ST-segment elevation, often in leads V1-V3, followed by a negative T-wave, known as a Type 1 pattern.” This pattern is so dangerous because it causes irregular heart beats which can cause sudden death during sleep or exercise.

Tricuspid atresia

2025-03-25 14:52:29 UTC

Tricuspid atresia is a congenital heart defect where the tricuspid valve is either not there and is just tissue instead, or does not function properly. In a normal individual, blood flows from the right atrium to the right ventricle and passes through the tricuspid valve, then is pumped to the lungs. In individuals with tricuspid atresia, blood can’t enter the lungs at all, or very little enters the lungs. The lack of a tricuspid valve causes an underdeveloped right ventricle, or one that does not function at all. In these patients' hearts, the oxygen poor blood enters a hole that connects the right and left atrium (sometimes there is a hole that connects the right atrium to the left ventricle as well), which results in the oxygen poor blood being pumped into the systemic circuit, rather than the pulmonary one. This causes these people to have low blood oxygen levels as well as shortness of breath, swelling, and buildup of fluids. This condition relates to our class because it disrupts the blood flow in the pulmonary and systemic circuit. It doesn’t allow blood to efficiently flow through the pulmonary circuit, which ultimately affects the flow of the systemic circuit since oxygen poor blood is being pumped into the body instead of oxygen rich blood.

Pacemaker syndrome

2025-03-25 17:12:05 UTC

Pacemaker syndrome is a condition in patients, in which the permanent pacemaker implanted into the heart to regulate their heart rate causes adverse effects due to the pace making mechanism. This occurs when pacemakers fail to synchronize within the heart's natural electrical activity, leading to physiological defects. At the physiological level, pacemaker syndrome occurs when the pacing of the heart is not coordinated with the natural atrial contraction. This can result in symptoms like loss of atrioventricular synchrony, which only paces the ventricles without ensuring that the atria had already fully contracted, resulting in reduced cardiac output. There can also be retrograde conduction, which causes the electrical signals from the ventricles to travel back to the Atria, causing wrong atrial contractions. It can definitely increase the workload of the heart because of the poorly programmed pacemaker, causing the heart to work ineffectively. This condition relates to class content because we learned how the SV and AV nodes work to initiate electrical signals that properly allow the atria and ventricles to contract in a timely manner. We also learned about the stroke volume of blood flow to the body from the heart and cardiac output but when the pacemaker syndrome occurs it causes the atrial contraction to be uncoordinated with the ventricle contraction, therefore the ventricles don't fill up properly leading to reduced stroke volume and cardiac output.

Cerebrovascular accident (stroke)

2025-03-25 17:43:28 UTC

A Cerebrovascular accident, which is commonly known as a stroke, happens when blood flow to part of the brain is blocked/interrupted. This can happen when a blood clot blocks a vessel (ischemic) or when a blood vessel bursts and causes bleeding in the brain (hemorrhagic). In both of these cases, brain cells are deprived of oxygen and nutrients which leads to them dying quickly. Without oxygen, the brain’s normal functions are disrupted. This leads to problems like muscle weakness, trouble speaking, vision changes, or confusion. This is all depending on which part of the brain is affected. In an ischemic stroke, the body struggles to produce enough energy and harmful chemicals will build up in brain cells. In a hemorrhagic stroke, bleeding increases pressure inside the skull which can worsen the damage. A stroke relates to our class content because it will affect many regions in the somatic nervous system and when talking about the hemorrhagic stroke. We just talked about the structure of blood vessels in different places in the body. For a blood vessels to burst the structure might not be as strong as it needs to be or there is a lot of pressure within the blood vessel.

pulmonary embolism

2025-03-25 20:29:22 UTC

Pulmonary embolisms are the result of a deep vein thrombosis in the leg (large blood clot) traveling up to the lungs. When in the lungs, a blood clot of this size becomes very dangerous as it blocks blood flow from the rest of the body, severely hindering gas exchange. The mechanism by which this clot can travel to the lungs begins with the detachment of the clot from the original vein into the blood stream. The clot then travels through the bloodstream to the right side of the heart before being pumped out. The clot becomes lodged in the pulmonary arteries, effectively blocking more blood from entering the pulmonary circuit; meaning the blood cannot be oxygenated and pumped to the rest of the body. This becomes problematic since the main purpose of the cardiovascular system is to deliver oxygen and other nutrients to tissues in the body which is essential for function. Lack of oxygen in the body is related to a cascade of life-threatening effects. This relates to our class in many ways, most importantly pertaining to the cardiac cycle, effects of disruption in blood circulation, and the body’s desire to maintain homeostasis.

eoreilly4_1 — 2025-03-25 20:56:02 UTC

Hypotension is a condition where your blood pressure is lower than the normal range of 120/80 mmHg. The range of hypotension is considered below 90/60 mmHg. This is caused when there is not enough pressure in the arteries to deliver oxygen-rich blood to internal organs and tissues. As a result, vital organs like the brain, heart, and kidneys may not receive enough oxygen or nutrients, which can lead to symptoms such as dizziness, fainting, fatigue, and even cause organ failure in severe cases. This condition directly relates to class material because the left side of the heart is responsible for pumping oxygenated blood at high pressure into the systemic circuit via the systemic arteries. When the rate or force of contraction of the left ventricle decreases, less pressure is generated, leading to a drop in systemic blood pressure and leading to hypotension.

Pericarditis

2025-03-26 01:03:24 UTC

Pericarditis is swelling and irritation of the sack-like tissue surrounding the heart. The cause of Pericarditis is often unknown; however, it can be caused by an immune response, infections, or injury. The inflammation may lead to fibrosis or thickening of the pericardium, which can progressively restrict the heart's movement. As a result, this restriction impairs the heart's ability to pump blood efficiently, reducing cardiac output. The inflamed pericardium may compress the heart, preventing it from properly filling with blood during diastole and ultimately causing low blood pressure. This condition relates to class because decreasing the pre load of a heart, decreasing the end diastolic volume of the heart, therefore decreasing the stroke volume. This decrease in stroke volume can put extra strain on the heart leading to a lower lifespan.

Coronary Heart Disease

awinchock — 2025-03-26 15:40:28 UTC

Coronary heart disease (CHD) is a cardiovascular condition characterized by the narrowing of coronary arteries due to the buildup of atherosclerotic plaques. These plaques, composed of cholesterol, fat, and cellular debris, reduce blood flow to the heart muscle, leading to ischemia (lack of oxygen). As a result, individuals with CHD may experience chest pain (angina), shortness of breath, or, in severe cases, myocardial infarction (heart attack).

Physiologically, CHD disrupts normal cardiovascular function by impairing the heart’s ability to receive adequate oxygenated blood. The endothelial dysfunction and chronic inflammation associated with CHD contribute to arterial stiffness and increased blood pressure, further straining the heart. Additionally, reduced coronary perfusion affects cardiac output and oxygen delivery to tissues, impacting overall systemic circulation.

This condition relates to class topics on cardiovascular physiology, including blood flow regulation and arterial function. CHD shows how atherosclerosis increases resistance in blood vessels, making it harder for the heart to pump blood. It also demonstrates the importance of healthy arteries and how the body tries to compensate by increasing heart rate or forming new blood vessels.

AFib

2025-03-26 16:00:19 UTC

Atrial fibrillation (AF) is a common cardiac arrhythmia caused by disorganized electrical activity in the atria.Instead of a normal contraction, the atria quiver due to rapid electrical impulses coming primarily from the pulmonary veins. Normally, the SA nodes generate rhythmic impulses that spread through the atria, AV node, and ventricles. In AF, pacemaker activity overrides the SA node, leading to loss of organized atrial contraction.

Because the atria fail to contract properly, there is a significant reduction in ventricular blood volume entering the ventricles. This can decrease cardiac output, especially in patients with preexisting heart diseases. The rapid atrial activity results in an unpredictable ventricular rhythm. The AV node filters these impulses, but the conduction varies, leading to an irregular heart rate. This variability can lead to palpitations, dizziness, and fatigue.

This relates to the class because it involves pacemaker cells and unlike normal pacemaker and contractile cell activity, AF is driven by these rapid atrial depolarizations that disrupt the usual conduction pathway. Also, medications such as beta-blockers or calcium channel blockers are used to manage heart rate and reduce stroke risk.

Aortic Dissection

2025-03-26 21:35:17 UTC

Aortic dissection is a condition where the innermost (intima) layer of the aorta tears. Blood going through this tear separates the aorta’s layers, causing severe pain and creating a new channel between the intimate and media layers. It can be caused by high blood pressure, trauma, an aortic aneurysm, or a connective tissue disorder. Symptoms include sudden chest pain that is often described as tearing or ripping, shortness of breath, pain in the neck and back, and dizziness. This relates to what we have learned about heart anatomy, as well as hemodynamics, as this causes a change in the vascular walls.

2025-03-26 22:44:26 UTC

Heart murmurs are abnormal heart sounds caused by turbulent blood flow through the heart, where the flow pattern becomes irregular and changes velocity unpredictably. These sounds can be detected with a stethoscope and may be classified as either innocent or pathological, with the latter potentially indicating a serious heart condition. This condition connects to our class discussions on normal heart sounds—"lub" (caused by AV valve closure) and "dub" (caused by semilunar valve closure). A heart murmur occurs when these sounds are disrupted. Physiologically, several factors can contribute to heart murmurs. One common cause is stenosis, or the narrowing of a valve, which forces the heart to work harder to push blood through, creating turbulent flow. Another cause is valvular regurgitation, where a valve fails to close properly, allowing blood to flow backward and producing abnormal sounds. This directly relates to our class material on valve function, as proper closure is essential to preventing backflow, and any disruption can interfere with normal circulation.

Sinus Bradycardia

2025-03-27 01:39:54 UTC

Sinus Bradycardia is when the heart rate is slower than the normal range. This occurs when the SA node generates electrical impulses slower than usual. This relates to our class because we learned how the SA node slows down contraction to allow the ventricles to be fully filled and emptied. However, this condition answers the question: What if the SA node slowed contraction more than it needed to? This condition also relates to class content because it is diagnosed via an ECG, where the QRS complexes are more spread apart. It is important to note that this condition can be found in healthy individuals. Many who are very active can find themselves with this condition. This is because it takes more effort to increase an active person’s heart rate; therefore, many active individuals start off with a slower heart rate. However, the condition can be concerning for those who experience shortness of breath, fatigue, and chest pain. If this is the case medications or devices are used to increase the heart rate back to the normal range.

Aortic Atherosclerosis

2025-03-27 01:44:05 UTC

Aortic atherosclerosis is when there is plaque built up in the inner linings of the aorta, or the tunica intima. This then causes the radius of the aorta to be smaller, thus increasing the resistance of blood flow which then also increases blood pressure in the arteries. This condition can cause more serious health complications such as stroke, aortic aneurysm, aortic dissection, and limb ischemia. This related to class because we learned about how different conditions of arteries can affect blood pressure, such as peripheral resistance. Atherosclerosis of the aorta can be treated with anti high blood pressure medications and medications to lower cholesterol, a contributor to plaque build-up.

Tachycardia

2025-03-27 03:32:23 UTC

Tachycardia is a medical condition that describes an increased heart rate. It is quantified as any resting heart rate that is greater than 100 beats per minute. It has a multitude of causes, including stress, certain medications, exercise, and underlying heart conditions. The condition itself can be temporary and is usually not concerning, however some types of tachycardia, like a persistent issue or when accompanied with chest pains, require medication intervention. In class, we discussed how normal heart rate is also an age dependent factor. A normal resting heart rate for an ultra-runner can be around 30bpm, for a regular and healthy adult can be around 60bpm, and for elderly it increases. We also discussed how blood pressure can affect heart rate, specifically how high blood pressure can increase heart rate. This condition is therefore more likely in elderly people and those with high blood pressure. This condition relates to class because we talked about the conditions that affect heart rate, and how heart rate eventually affects cardiac output. We also talked about dysrhythmias, which is described as a disturbance in the electrical rhythm in the heart; tachycardia is a dysrhythmia. Additionally, we talked about how tachycardia can reduce stroke volume, as the heart doesn’t have proper time to fully fill with blood before having another contraction. With less blood in the ventricle, less blood is being sent with each beat.

Mitral Valve Regurgitation

2025-03-27 14:57:11 UTC

The mitral valve, also known as the bicuspid valve, sits between the left atrium and the left ventricle. It opens when blood moves from the left atrium into the left ventricle during the ventricular filling phase. Mitral regurgitation happens when the mitral valve does not close properly. It can be caused by several different things including a heart attack, disease, or heart defects. During the isovolumetric contraction phase and ventricular ejection phase, the mitral valve should remain closed. Mitral regurgitation allows for blood to go back into the atrium during ventricular contraction because of the mitral valve not closing properly. This relates to the course because it has an impact on the cardiac cycle, can change heart sounds, and pressure in the ventricles. The heart will have to work harder to get proper amount of blood out of the left ventricle and into the aorta. The severity can differ from person to person, most people are okay if they get proper treatment.

Aneurysm

2025-03-27 16:21:35 UTC

Aneurysms are weak or expanded areas of a blood vessel, most commonly found in arteries. Someone can live with an aneurysm for many years and have no idea. There are generally no symptoms that come along with an aneurysm unless it bursts. If an aneurysm ruptures, it can lead to life threatening bleeding. If a doctor happens to find an aneurysm during a checkup, its size will be closely monitored and necessary steps will be taken to prevent a rupture. These steps can include medication or surgery. In class we have learned about what size an artery should be depending on its function. Aneurysms can have several different causes including high blood pressure and genetic predisposition. High blood pressure can damage the arterial wall, weakening it and causing the blood vessel to expand. In class we have learned about the role of arteries, as well as factors that impact blood pressure.

Cleveland Clinic. 2022 Apr 16. Aneurysm: What it is, types, symptoms, diagnosis & treatment. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/22769-aneurysm.

Mayo Clinic. 2023 Apr 25. Abdominal aortic aneurysm - Symptoms and causes. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/abdominal-aortic-aneurysm/symptoms-causes/syc-20350688.

Buerger's Disease

2025-03-27 20:02:42 UTC

People with Buerger’s Disease are majority heavy smokers. The exact reason why Buerger’s Disease appears most frequently in smokers is not exactly known, but it is believed by scientists that the physiological changes are a result of interactions with chemicals from tobacco. People with Buerger’s Disease experience pain in their hands, feet, legs, and arms. The pain is caused due to inflammation in the blood vessels. This inflammation can further lead to the formation of blood clots. Buerger’s Disease is a practical application for the formula for Peripheral Resistance in the blood vessels. Decreasing the diameter of the blood vessels because their inflamed will in turn decrease the radius. A decreased radius in the formula for peripheral resistance will increase the resistance because the radius is in the denominator. The increase in blood pressure that coincides with an increase in peripheral resistance can lead to larger complications like strokes and heart attacks. Patients with Buerger’s Disease will be given vasodilators or anti-inflammatories to help the diameter for the blood vessels return to a normal diameter.

Adam-Stokes Syndrome

2025-03-27 20:21:04 UTC

Adam-Stokes Syndrome is a condition in which those affected experience fainting spells, also known as syncope, as a result of the heart beating abnormally preventing the proper flow of oxygen and blood to the brain. The most common cause of this phenomenon is an atrioventricular blockage, a blockage between one of the two atria and the inferior ventricle. Other potential causes include bradycardia (heartbeat under 60 bpm), ventricular fibrillation (the ventricles constrict and move irregularly and erratically), ventricular tachycardia (heartbeat over 120 bpm in the ventricles), and least commonly paroxysmal ventricular standstill (the ventricles stop contracting all together). To be diagnosed with this condition, a patient will undergo an EKG/ECG, a tilt table test, blood testing, an electrophysiological study, and a carotid sinus massage, in which a doctor will apply pressure to a patient's carotid sinus for a few seconds to see how the heart responds. This condition relates to material we have covered in class as an atrioventricular blockage prevents or slows down the passage of blood from the atria to the ventricles thus negatively impacting the overall blood flow of the heart. Blockages such as these alters the various components of one's heart beat which, as a result, creates adverse effects for the systemic and pulmonary systems. With less blood flow going to the brain via the systemic system, syncope is able to occur.

Thrombosis

2025-03-27 22:05:50 UTC

Thrombosis is a serious condition where one or more blood clots form in your blood vessels or heart. Blood clots can block blood flow in your blood vessels or break free and travel elsewhere in your body. Some people face higher risk of thrombosis due to medical conditions or other factors. If the clot travels to different locations, it can cause different health problems. In the heart, it could cause a heart attack. The clot can form due to a buildup of plaque, low blood flow activity, or damage to artery lining. In class, we have talked about the varying sizes or blood vessels throughout the body. If a clot gets stuck in a small vessel in the heart, it will clog the vessel and lead to a backup of blood. With the blood not able to travel where it needs to go in the heart, it would ultimately lead to a heart attack and possible death.

Varicose Veins

2025-03-28 01:13:04 UTC

Varicose Veins are enlarged, twisted veins that typically occur in the lower extremities. This happens due to valves in the veins, which typically prevent blood from traveling backwards, become weakened. This creates blood pooling in the veins which results in increased venous pressure, vessel dilation and the typical bulging appearance through the skin. Over time, this can create leg pain, swelling and a heavy sensation. This directly relates to the course on the cardiovascular system and blood flow regulation. Varicose veins show how venous return is influences by valve function, skeletal muscle contraction and venous pressure.

2025-03-28 03:05:18 UTC

Aortic stenosis is a condition where the aortic valve doesn't fully open restricting blood flow from the left ventricle going into the aorta and then to the rest of the body. The narrowing of the valve makes the heart have to work harder than normal during in regards to systolic pressure. This increases the pressure inside of the left ventricle resulting in the thickening of the heart muscle called ventricular hypertrophy. This condition is relevant to what we learned in class because of the effect it has on cardiac output and stroke volume. Aortic stenosis decreases stroke volume because of narrowed valve and hypertrophy. Cardiac output decreases which is why patients have symptoms like fatigue and poor circulation. It also relates to the relationship between pressure and volume which we covered in class. Aortic stenosis alters the pressure volume loop of the left ventricle. We also learned about how consistent high pressure from high afterload causes the left ventricle wall to thicken, which may eventually lead to diastolic dysfunction which is exactly what happens in aortic stenosis. Aortic stenosis is tied to our current unit and future exam because it affects blood flow, involves valve anatomy and function, and it affects physiology of the heart.

Aortic Coarctation

rkolte1 — 2025-03-28 03:08:49 UTC

Aortic coarctation is a disorder where there is a narrowing of the aorta. Coarctation of the aorta is most typically present at birth and is generally considered a congenital defect, but in some cases the aorta can narrow later in life(due to extreme buildup of cholesterol or traumatic injury).The condition makes it so the heart is forced to work harder to pump blood. At a physiological level, the aorta is narrowed, which increases peripheral resistance. To make up for this, the left lower heart chamber specifically has to work harder and this makes blood pressure rise significantly.

In class we have extensively covered events of the cardiac cycle. This disorder directly relates to this portion of class content because the ventricular ejection phase is the event at which there are the most complications that occur since this is exactly when blood is ejected into the already narrower/obstructed aorta. When looking at a Wiggers diagram, it is typical for the ventricular pressure to rise over the aortic pressure, but with this disorder the ventricular pressure will rise much more.

Ebstein's Anomaly

2025-03-28 03:20:42 UTC

Ebstein’s Anomaly is congenital heart defect characterized by a underdeveloped tricuspid valve This valve separates the right atrium and right ventricle and the defect can range in severity. A defect of this kind dysregulates blood flow allowing blood to pump back into the right atrium due to the extremely low volume of the right ventricle. The inability of the blood to efficiently exit the right side of the heart leads to cyanosis, shortness of breath—from the lack of oxygenated blood reaching the body, and heart palpitations. This relates to class content as we examine the importance of blood flowing efficiently through the heart. The heart pumps harder in attempt to modulate around the lack of flow despite it being stroke volume is decreased. The inability for blood to exit this part of the heart inhibits oxygenated blood from reaching the lungs, causing symptoms of shortness of breath. That also effects a person’s ability to exercise and eventually heart failure from the lack of oxygen and overexertion.

Wolff-Parkinson-White (WPW) syndrome

2025-03-28 03:52:49 UTC

Wolff-Parkinson-White (WPW) syndrome is a congenital heart defect causing a much faster heart rate in patients due to an extra pathway, sometimes called an accessory pathway (AP), and in the case of WPW - the Bundle of Kent - to allow the original signal to bypass the AV node. This condition relates to this class because in patients with WPW, it focuses on the role of the AV node in regulating heart rhythms. During the lecture we talked about the cardiac conduction system which includes the SA and AV nodes sending electrical currents throughout the heart telling the atria and ventricles when to contract. When the signal bypasses the AV node, it leads to an early activation, or pre-excitation, of the ventricles, predisposing patients to an increased heart rate. The AP can affect the electrical conduction in a few ways - conducting the impulse in both directions, away from the ventricle, or towards the ventricle. As discussed in class, we need the signal to pass through the AV node to slow down the impulses before they reach the ventricles, but in WPW the patient is at a risk for an increased heart rate by bypassing the AV node. This condition also relates to our discussion of ECG’s, diagnosing WPW is much easier to do via an ECG because bypassing the AV node shows up as a “delta wave” on a scan and there is a much shorter PR interval.