$CO = HR \times SV$; it measures the amount of blood pumped out by each ventricle per minute.

$CO = 80 \times 60 = 4800$ mL/min

Question 1

Which equation correctly represents cardiac output (CO) and what does it measure?

Accepted Answer

$CO = HR 	imes SV$; it measures the amount of blood pumped out by each ventricle per minute.

Question 2

A patient has a heart rate of 80 beats/min and a stroke volume of 60 mL/beat. What is their cardiac output?

Accepted Answer

$CO = 80 	imes 60 = 4800$ mL/min

Question 3

Which of the following best describes the Frank-Starling law of the heart?

Accepted Answer

The greater the preload (stretch), the greater the force of contraction and stroke volume.

Question 4

Which factor is most directly responsible for increasing preload in the heart?

Accepted Answer

Increased venous return

Question 5

A patient with persistent high blood pressure is at risk for which of the following cardiac changes?

Accepted Answer

Myocardial hypertrophy and increased ESV

Question 6

Which of the following is a positive inotropic agent that increases contractility?

Accepted Answer

Epinephrine

Question 7

What is the effect of increased afterload on stroke volume (SV)?

Accepted Answer

It decreases SV by increasing ESV.

Question 8

Which heart sound is associated with the closing of the atrioventricular (AV) valves?

Accepted Answer

The first heart sound ("lub")

Question 9

A patient presents with pulmonary edema, enlarged heart, and distended neck veins. Which type of heart failure is most likely present?

Accepted Answer

Left-sided heart failure

Question 10

Which congenital heart defect is characterized by a narrowed aorta, increasing the workload on the left ventricle?

Accepted Answer

Coarctation of the aorta

Question 11

Which of the following best describes the effect of the sympathetic nervous system on the heart?

Accepted Answer

It increases heart rate and contractility via norepinephrine binding to $\beta_1$-adrenergic receptors.

Question 12

Which ion imbalance is most likely to cause heart block and cardiac arrest?

Accepted Answer

Hyperkalemia

Question 13

A 25-year-old athlete has a resting heart rate of 55 beats/min. What is the most likely explanation?

Accepted Answer

Endurance training has increased vagal tone, resulting in bradycardia.

Question 14

Which of the following is a likely consequence of coronary atherosclerosis?

Accepted Answer

Impaired oxygen delivery to cardiac cells, leading to hypoxia and inefficient contraction.

Question 15

Which of the following is the correct formula for stroke volume (SV)?

Accepted Answer

$SV = EDV - ESV$

Question 16

A patient with a heart murmur is most likely experiencing which of the following?

Accepted Answer

Valve problems causing abnormal heart sounds when blood hits obstructions.

Question 17

Which of the following is a common age-related change affecting the heart?

Accepted Answer

Sclerosis and thickening of valve flaps, leading to murmurs.

Question 18

Which hormone, released from the adrenal medulla, increases heart rate and contractility?

Accepted Answer

Epinephrine

Question 19

Which of the following best describes the Bainbridge (atrial) reflex?

Accepted Answer

An increase in venous return stretches atrial walls, stimulating the SA node and increasing heart rate.

Question 20

Which congenital heart defect involves a combination of four abnormalities, including a narrowed pulmonary trunk and ventricular septal defect?

Accepted Answer

Tetralogy of Fallot

Cardiac Output, Heart Rate, and Stroke Volume: Regulation and Clinical Aspects

Study Guide - Practice Questions