CVD Pathophysiology

Question 1

What percent of strokes are ischemic vs hemorrhagic?

Answer 1

85% ischemic

Question 2

CHD stands for _________.

Answer 2

Coronary Heart Disease

Question 3

CHD is a ____________ related disorder.

Answer 3

atherosclerosis

Question 4

What is the rate-pressure product?

Answer 4

a measure of cardiac workload calculated by multiplying heart rate by systolic blood pressure. It reflects myocardial oxygen demand.

Question 5

Why does stable angina resolve with rest?

Answer 5

The heart’s oxygen demand decreases when physical activity stops, reducing the strain on the heart and improving the balance between oxygen supply and demand.

Question 6

Why does stable angina resolve with nitroglycerine?

Answer 6

It dilates blood vessels, reducing the heart’s workload by decreasing preload and afterload. This improves blood flow to the heart and balances oxygen supply with demand.

Question 7

Why do cold, stress, or smoking exacerbate variant angina?

Answer 7

By triggering vasoconstriction of coronary arteries. This further reduces blood flow to the heart, leading to spasms and oxygen supply imbalance, which worsens angina symptoms.

Question 8

Why does exercise improve Variant angina symptoms?

Answer 8

Vasodilation increases blood flow to the heart.

Question 9

Why are the smallest branches of the coronary circulation found on the inside of the heart wall?

Answer 9

They supply the inner layers of the myocardium, which require a direct oxygen supply due to high metabolic activity.

Question 10

When does isovolumic contraction occur during the cardiac cycle?

Answer 10

During early systole, right after the mitral and tricuspid valves close but before the aortic and pulmonary valves open. The ventricles contract with no volume change as pressure builds.

Question 11

Which has a poorer prognosis – transmural of subendocardial?

Answer 11

Transmural because they involve the full thickness of the heart wall, leading to more extensive damage.

Question 12

How are tissue ischemia, injury and infarct different?

Answer 12

Ischemia: Reduced blood flow, causing reversible oxygen deprivation.

Injury: Prolonged ischemia leading to damage, but still potentially reversible.

Infarct: Tissue death (necrosis) due to prolonged, irreversible injury from lack of blood flow.

Question 13

Where does contraction begin in the heart? How does this affect cardiac output?

Answer 13

The sinoatrial (SA) node in the right atrium. This top-down contraction allows for effective filling of the ventricles and maximizes cardiac output by ensuring that blood is pushed efficiently from the atria to the ventricles before the ventricles contract.

Question 14

What problems occur when blood remains in the atria?

Answer 14

Atrial Fibrillation: Increased risk of arrhythmias due to chaotic electrical activity.

Thrombus Formation: Stasis of blood can cause clot formation, increasing the risk of stroke.

Increased Pressure: Elevated pressure can lead to heart failure and pulmonary congestion.

Dilation of Atria: Over time, the atria can enlarge, leading to further complications.

Question 15

What are the names of the 4 valves in the heart? Where are they located?

Answer 15

Tricuspid Valve: Located between the right atrium and right ventricle.

Pulmonary Valve: Located between the right ventricle and pulmonary artery.

Mitral Valve (or Bicuspid Valve): Located between the left atrium and left ventricle.

Aortic Valve: Located between the left ventricle and aorta.

Question 16

What is the pericardium?

Answer 16

A double-walled sac that surrounds and protects the heart.

Question 17

How does cardiac tamponade alter End Diastolic Volume?

Answer 17

The accumulation of fluid in the pericardial space compresses the heart, limiting its ability to expand fully during diastole. This decreases the volume of blood the heart can hold before contraction, leading to impaired filling and reduced cardiac output.

Question 18

How do mural thrombus directly alter stroke volume?

Answer 18

By obstructing blood flow within the heart or the great vessels, reducing the amount of blood that can be ejected during ventricular contraction.

Question 19

Where will mural thrombi travel to if originating in the left ventricle?

Answer 19

They can travel to the systemic circulation, potentially leading to embolisms in various locations, such as the brain (causing ischemic stroke), the limbs, or other organs.

Question 20

Where will mural thrombi travel to if originating in the right ventricle?

Answer 20

They can travel to the pulmonary circulation, potentially causing a pulmonary embolism by lodging in the pulmonary arteries.

Question 21

Blockage in which arteries is most likely to cause: Brady-arrhythmia?

Answer 21

right coronary artery (RCA)

Question 22

Blockage in which arteries is most likely to cause: Left atrial dyskinesia?

Answer 22

left circumflex artery as it supplies blood to the lateral and posterior walls of the left atrium.

Question 23

Blockage in which arteries is most likely to cause: Bundle branch block?

Answer 23

Left anterior descending artery (LAD) or the right coronary artery (RCA) is most likely to cause bundle branch block, as these arteries supply the conduction pathways, including the bundle branches.

Question 24

Blockage in which arteries is most likely to cause: Left ventricular dyskinesia?

Answer 24

Left anterior descending artery

Question 25

Identify 5 S/S of CHD:

Answer 25

Angina
SOB / dyspnea
Fatigue / weakness
Hypotension

Question 26

What are the 2 determinants of myocardial oxygen supply?

Answer 26

Coronary Blood Flow: The amount of blood delivered to the heart muscle through the coronary arteries.

Oxygen Content of the Blood: The amount of oxygen carried in the blood, which depends on factors like hemoglobin levels and oxygen saturation.

Question 27

Which type of angina resolves with rest?

Answer 27

Stable angina

Question 28

What is angina?

Answer 28

chest pain or discomfort caused by reduced blood flow and oxygen to the heart muscle. It typically occurs during physical activity, stress, or emotional upset and is relieved by rest or nitroglycerin.

Question 29

Describe CCS 4 Classification of Angina.

Answer 29

Class I: Angina occurs with strenuous or prolonged activity but does not limit usual activities.

Class II: Angina occurs with moderate activity (e.g., walking, climbing stairs) and may limit some activities.

Class III: Angina occurs with minimal activity (e.g., walking short distances) and significantly limits daily activities.

Class IV: Angina occurs at rest or with any physical activity, making it impossible to carry out any physical activity without discomfort.

Question 30

What is a transmural myocardial infarction?

Answer 30

A type of heart attack that involves necrosis of the full thickness of the myocardial wall.

Question 31

What are the 5 physiological consequences of AMI?

Answer 31

Myocardial Necrosis: Death of heart muscle cells due to prolonged ischemia.

Decreased Cardiac Output: Reduced ability of the heart to pump blood, leading to inadequate perfusion of tissues.

Heart Failure: Impaired contractility may lead to heart failure symptoms, such as shortness of breath and fluid retention.

Arrhythmias: Disturbances in the heart’s electrical conduction can cause various arrhythmias, which may be life-threatening.

Compensatory Mechanisms: The body may activate mechanisms like increased heart rate and systemic vasoconstriction to maintain blood pressure and perfusion, potentially leading to further complications.

Question 32

What medical diagnostic test is considered definitive for coronary heart disease?

Answer 32

Coronary angiography

Question 33

How are diastolic and systolic dysfunction different?

Answer 33

Systolic dysfunction affects the heart’s ability to pump, while diastolic dysfunction affects its ability to fill.

Question 34

What is cardiac tamponade?

Answer 34

fluid accumulates in the pericardial space, exerting pressure on the heart. This pressure restricts the heart’s ability to fill properly during diastole, leading to decreased cardiac output.

Question 35

When oxygen demand exceeds the supply, cell death occurs in about __________.

Answer 35

4 hours