Cardiology Quiz: Understanding Heart Functions

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Questions and Answers

What is the primary event occurring during diastole?

Contraction of the atria.

Ejection of blood into the aorta and pulmonary arteries.

Relaxation of the ventricles and filling with blood. (correct)

Closure of the atrioventricular valves.

Cardiac output is determined by what two factors?

Preload and afterload.

Arterial pressure and pulmonary pressure.

Heart rate and stroke volume. (correct)

Venous return and systemic pressure.

Which of the following best defines an aneurysm?

A temporary blockage of an artery by a traveling clot.

A hardening of the arterial walls due to plaque buildup.

A restriction of an artery that can cause hypertension.

An abnormal, localized dilation of an artery due to a weakened vessel wall. (correct)

What is the primary characteristic of hypertension?

A sustained elevation of blood pressure in the arterial system. Signup and view all the answers

A patient's resting cardiac output is 5 L/min, and during exercise, it increases to 20 L/min. What is their cardiac reserve?

15 L/min Signup and view all the answers

Which of the following best describes preload?

The end-diastolic pressure when the ventricle has filled. Signup and view all the answers

Which of the following is considered a non-modifiable risk factor for primary hypertension?

Family history and genetics. Signup and view all the answers

What primarily determines afterload for the left ventricle?

Systemic arterial pressure Signup and view all the answers

Which of these lifestyle factors is considered a modifiable risk for primary hypertension?

High alcohol consumption. Signup and view all the answers

Which of the following is a common cause of secondary hypertension?

Renal artery stenosis. Signup and view all the answers

Ischemia is best defined as:

A reduction in arterial flow insufficient to meet tissue oxygen demands. Signup and view all the answers

What is infarction characterized by?

An area of ischemic necrosis due to arterial blockage. Signup and view all the answers

What hormone-secreting tumor of the adrenal medulla causes increased blood pressure, headaches, sweating and panic attack symptoms?

Pheochromocytoma. Signup and view all the answers

Which of the following describes vasculitis?

An inflammation of the blood vessel wall. Signup and view all the answers

A patient presents with higher blood pressure in their upper extremities compared to their lower extremities, along with delayed femoral pulses. Which condition may be present?

Coarctation of the aorta. Signup and view all the answers

What are metanephrines, which are elevated in patients with pheochromocytoma?

Breakdown products of catecholamines. Signup and view all the answers

Which chamber of the heart receives deoxygenated blood from the systemic circulation?

Right atrium Signup and view all the answers

What is the primary function of the atrioventricular valves?

To control the direction of blood flow from the atria to the ventricles. Signup and view all the answers

During which phase of the cardiac cycle do the ventricles contract?

Systole Signup and view all the answers

Which of the following best explains the role of the left ventricle?

Pumping blood into the systemic circulation Signup and view all the answers

What is the primary function of the right ventricle during the cardiac cycle?

To pump blood to the lungs Signup and view all the answers

Which of the following is the correct sequence of blood flow through the heart?

Right Atrium -> Right Ventricle -> Pulmonary Circulation -> Left Atrium -> Left Ventricle -> Systemic Circulation Signup and view all the answers

If the heart is described as a four-chambered pump, which chambers are responsible for receiving blood?

The two atria. Signup and view all the answers

Which process best describes the phase of the cardiac cycle when the ventricles are relaxed and filling with blood?

Diastole Signup and view all the answers

Which condition is associated with surges in systolic and diastolic pressure during sleep, contributing to elevated nighttime blood pressure?

Obstructive sleep apnea (OSA) Signup and view all the answers

What is a common characteristic of primary hypertension, before target-organ damage occurs?

Asymptomatic disorder Signup and view all the answers

Which of the following is a direct consequence of increased intravascular pressure on vascular endothelial cells?

Increased risk of atherosclerotic vascular disease Signup and view all the answers

What is the primary mechanism by which hypertension contributes to damage in the kidneys?

Glomerular hypoperfusion and endothelial dysfunction Signup and view all the answers

How does the heart typically respond to the increased workload imposed by elevated blood pressure?

Remodeling and hypertrophy of the left ventricular wall Signup and view all the answers

What effect does hypertension have on the small penetrating arteries in the subcortical region of the brain?

Narrowing and sclerosis leading to hypoperfusion Signup and view all the answers

Which of the following is an initial change in the eyes due to hypertension?

Generalized arteriolar narrowing due to increased vasomotor tone Signup and view all the answers

Which of the following is NOT a typical long-term effect of hypertension?

Improved kidney function Signup and view all the answers

Which of the following best describes the primary characteristic of diastolic dysfunction?

Increased resistance to ventricular filling with increased filling pressures. Signup and view all the answers

What is a key consequence of right ventricular failure in terms of systemic circulation?

Reduced blood flow and congestion of blood into the systemic venous system. Signup and view all the answers

Hepatic congestion and hepatomegaly in right-sided heart failure is primarily due to:

Blood back up in hepatic veins draining into the inferior vena cava. Signup and view all the answers

What is the primary mechanism behind pulmonary edema in left-sided heart failure?

The shift of intravascular fluid into the lung interstitium due to increased pulmonary capillary pressure. Signup and view all the answers

If portal circulation is congested due to right-sided heart failure, which of the following conditions might develop?

Splenic engorgement and ascites. Signup and view all the answers

What is a direct result of impaired left heart function?

Decreased cardiac output to the systemic circulation. Signup and view all the answers

How does the sympathetic nervous system respond to decreased cardiac output (CO) in Heart Failure?

It increases cardiac sympathetic tone and catecholamine levels. Signup and view all the answers

Which clinical finding is most indicative of severe right-sided heart failure?

Distended external jugular veins when sitting up or standing. Signup and view all the answers

What is the initial effect of the sympathetic nervous system on maintaining organ perfusion?

Increasing heart rate and cardiac contractility. Signup and view all the answers

What physiological responses are associated with the stimulation of β-adrenergic receptors by increased sympathetic activity?

Tachycardia, vasoconstriction, and cardiac arrhythmias. Signup and view all the answers

How does reduced cardiac output in heart failure affect renal function, according to the text?

It decreases renal blood flow and glomerular filtration rate. Signup and view all the answers

What is the primary function of aldosterone in the renin-angiotensin-aldosterone mechanism?

To increase tubular reabsorption of sodium and water. Signup and view all the answers

What do Angiotensin II and aldosterone stimulate in addition to fluid retention?

Stimulation of inflammatory cytokine production. Signup and view all the answers

What is the result of fibroblast and collagen deposition in the context of heart failure?

Ventricular remodeling and progression of ventricular dysfunction. Signup and view all the answers

Which of the following describes eccentric hypertrophy?

A disproportionate increase in muscle length, typically seen in Dilated cardiomyopathy (DCM). Signup and view all the answers

When diagnosing heart failure, what is the primary focus of diagnostic methods?

Determining the specific cause and the extent of the disorder. Signup and view all the answers

Study Notes

Cardiovascular Disorders: Pathophysiology

The heart is a four-chambered pump with two atria and two ventricles.
The right atrium receives deoxygenated blood returning from the systemic circulation.
The left atrium receives oxygenated blood from the lungs.
The right ventricle pumps blood to the lungs.
The left ventricle pumps blood into the systemic circulation.
Heart valves control the direction of blood flow from atria to ventricles.

Cardiac Cycle

The cardiac cycle describes the rhythmic pumping action of the heart.
Systole: Ventricular contraction.
Diastole: Ventricular relaxation and filling with blood.

Regulation of Cardiac Performance

Cardiac output (CO) is a measure of the heart's efficiency.
CO = Stroke Volume (SV) × Heart Rate (HR).
Average resting CO in adults is 4 to 6 L/minute.
Cardiac reserve is the maximum percentage increase in CO above resting levels.
Resting CO = 4-6 L/min
Vigorous Exercise = 21 L/min
Preload is end-diastolic pressure; venous return influences preload
Afterload is the work required to move blood into the aorta. Systemic arterial pressure is the main source of afterload on the left heart, and pulmonary arterial pressure is the main source of afterload on the right heart.
Factors influencing heart rate (HR) include autonomic innervation, hormones, fitness levels, and age.
Factors influencing stroke volume (SV) include heart size, gender, contractility, duration of contraction, preload, and afterload

Disorders of Systemic Arterial Blood Flow

Ischemia is the reduction in arterial blood flow insufficient to meet the oxygen demands of the tissues.
Infarction is an area of ischemic necrosis in an organ caused by occlusion of its arterial blood supply or venous drainage.
Atherosclerosis is a gradual buildup of fibro-fatty plaques in the intima of large and medium-sized blood vessels
Vasculitis is the inflammation of blood vessel walls leading to tissue injury and necrosis.
Aneurysms are abnormal localized dilatations of an artery due to a weakness in the vessel wall.

Hypertension

Hypertension is a sustained elevation of arterial blood pressure within the arterial circuit.
It's a major risk factor for cardiovascular disease and a leading cause of morbidity and mortality worldwide.
Primary hypertension occurs without identifiable causes; secondary hypertension arises due to other conditions like kidney disease.
Hypertension classifications (American Heart Association): Normal (<120/80 mmHg), Elevated (120-129/<80 mmHg), Stage 1 Hypertension (130-139/80-89 mmHg), Stage 2 Hypertension (≥140/90 mmHg).
Nonmodifiable risk factors for primary hypertension include age and gender.
Modifiable risk factors include uncontrolled glucose levels (diabetes), lipid disorders, obesity, hyperuricemia, metabolic syndrome, and unhealthy lifestyle habits (smoking, alcohol, sedentary behavior).
Secondary hypertension causes include drug use, kidney disease, adrenal gland disorders, and others.

Target-Organ Damage

Increased perfusion pressure can damage target organs and blood vessels.
Target-organ damage particularly affects highly vascular organs dependent on adequate blood supply (heart, kidney, brain, eyes).
Hypertension is a leading cause of: Ischemic heart disease, end-stage renal disease, visual impairment/blindness caused by retinopathy

Heart and Hypertension

Elevated blood pressure increases the workload on the left ventricle.
Left ventricular hypertrophy (LVH) is a common response to compensate for increased workload.
This can increase risk of coronary heart disease, cardiac arrhythmias, sudden death, and congestive heart failure.

Kidney and Hypertension

Hypertension causes damage to the kidneys through glomerular hypoperfusion, glomerulosclerosis and tubulointerstitial fibrosis.
Also contributes to endothelial dysfunction and accelerates other kidney diseases (like diabetic nephropathy).

Brain and Hypertension

Hypertension can contribute to narrowing and sclerosis of small penetrating arteries in the subcortical regions.
This leads to hypoperfusion, impaired blood-brain barrier, and potential subcortical white matter demyelination.

Eyes and Hypertension

Increased vasomotor tone, followed by sclerotic changes (media wall hyperplasia, intimal thickening, hyaline degeneration) in the arterioles are effects of prolonged hypertension.
This can lead to further problems like retinal arteriovenous (AV) nicking and blindness.
Acute hypertension can also cause hemorrhages, microaneurysms, and hard exudates.

Congestive Heart Failure (CHF)

A complex syndrome caused by a structural or functional disorder in the heart, impacting its ability to effectively pump and increasing risk of low cardiac output, pulmonary, and systemic congestion.
Causes include coronary artery disease (CAD), hypertension, dilated cardiomyopathy, and valvular heart disease.
Important compensations occur with heart failure ( Frank-Starling mechanism.
Classification of CHF includes stages A (high risk), B (structural heart disease), C (symptoms of heart failure with structural heart disease), and D (advanced heart disease with symptoms at rest with max therapy).

Systolic vs. Diastolic Dysfunction

Systolic dysfunction is characterized by reduced ejection fraction (typically <40%) and an enlarged left ventricle.
Diastolic dysfunction involves increased resistance to filling with increased filling pressures but with a normal or slightly enlarged ventricle.
Right-sided dysfunction causes peripheral edema, and blood backs into the systemic venous system if RV fails.

Compensatory Mechanisms in Heart Failure

Mechanisms like the Frank-Starling mechanism, sympathetic nervous system activation, and renin-angiotensin-aldosterone system activation initially help maintain the cardiac output and perfusion of vital organs. This initial increase in sympathetic tone may increase the workload on the heart.

Remodeling of the Heart

The heart responds to chronic stress by remodeling, which comprises myocardial hypertrophy and the accompanying changes in cardiac structure.

Diagnosis and Treatment

Diagnostic techniques and treatments aim to identify the cause, correct it if possible, restore cardiac function, and control fluid volumes.
Various medications including diuretics, ACE inhibitors, angiotensin receptor blockers, beta blockers, digoxin, and vasodilators are used to treat heart failure.
Mechanical support via devices like ventricular assist devices (VADs) may be necessary in severe cases.
Heart transplantation is the preferred treatment in cases of end-stage heart failure.

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Description

Test your knowledge on key concepts related to cardiology, including diastole, cardiac output, hypertension, and various cardiovascular conditions. This quiz will assess your understanding of vital cardiovascular mechanisms and risk factors. Ideal for students studying cardiology or healthcare professionals looking to reinforce their knowledge.