ACSM-EP Cardiovascular Physiology 5 — Questions and Answers
Question 1: What is the expected blood pressure response during a graded exercise test in a normotensive individual?
- Both systolic and diastolic pressure increase proportionally
- Systolic pressure rises progressively; diastolic pressure remains stable or slightly decreases (Correct answer)
- Diastolic pressure rises significantly while systolic pressure is unchanged
- Both pressures remain constant until near-maximal intensity
Correct answer: Systolic pressure rises progressively; diastolic pressure remains stable or slightly decreases
During graded exercise, systolic blood pressure increases with workload due to rising cardiac output, while diastolic pressure remains stable or may slightly decrease due to peripheral vasodilation.
Question 2: Which of the following is an abnormal blood pressure response that would warrant stopping a graded exercise test?
- Systolic BP rising from 120 to 185 mmHg
- Diastolic BP increasing from 80 to 100 mmHg
- Systolic BP dropping more than 10 mmHg below baseline despite increasing workload (Correct answer)
- Heart rate increasing from 70 to 150 bpm
Correct answer: Systolic BP dropping more than 10 mmHg below baseline despite increasing workload
An exertional drop in systolic BP of >10 mmHg below baseline is a relative contraindication for exercise and may indicate severe left ventricular dysfunction or outflow obstruction.
Question 3: Which plasma protein is MOST responsible for maintaining oncotic pressure and preventing fluid from leaking from capillaries into interstitial spaces?
- Fibrinogen
- Immunoglobulin G
- Albumin (Correct answer)
- Hemoglobin
Correct answer: Albumin
Albumin accounts for approximately 80% of plasma oncotic pressure, drawing fluid back into the capillaries from the interstitium.
Question 4: During prolonged exercise in the heat, which cardiovascular phenomenon is referred to as 'cardiovascular drift'?
- Progressive increase in stroke volume with unchanged heart rate
- Gradual rise in heart rate with declining stroke volume due to fluid shifts and cutaneous vasodilation (Correct answer)
- Steady increase in mean arterial pressure over time
- Progressive decrease in cardiac output despite stable heart rate
Correct answer: Gradual rise in heart rate with declining stroke volume due to fluid shifts and cutaneous vasodilation
Cardiovascular drift occurs during prolonged exercise, especially in heat, as plasma volume decreases (sweating) and blood is diverted to the skin, reducing venous return, stroke volume, and thus requiring heart rate to rise to maintain cardiac output.
Question 5: What is the primary role of the sinoatrial (SA) node?
- Slowing conduction through the atrioventricular junction
- Initiating the electrical impulse that triggers each cardiac cycle (Correct answer)
- Coordinating ventricular repolarization
- Regulating stroke volume via autonomic input
Correct answer: Initiating the electrical impulse that triggers each cardiac cycle
The SA node is the heart's primary pacemaker, spontaneously generating action potentials at 60–100 bpm that initiate each cardiac cycle.
Question 6: Which measure best reflects the workload on the heart and is commonly used to estimate myocardial oxygen demand during exercise testing?
- Cardiac output
- Rate-pressure product (RPP = HR × SBP) (Correct answer)
- Mean arterial pressure alone
- Stroke volume index
Correct answer: Rate-pressure product (RPP = HR × SBP)
The rate-pressure product (double product) correlates closely with myocardial oxygen consumption and is a standard clinical estimate of cardiac work during exercise.
Question 7: Which statement correctly describes the relationship between venous return and cardiac output under normal physiological conditions?
- Cardiac output can chronically exceed venous return
- Venous return and cardiac output are equal over time, as the heart pumps whatever blood it receives (Correct answer)
- Cardiac output always exceeds venous return during exercise
- Venous return is determined exclusively by heart rate
Correct answer: Venous return and cardiac output are equal over time, as the heart pumps whatever blood it receives
By Starling's law and conservation of mass, cardiac output must equal venous return in a steady state, as the heart cannot pump more blood than it receives.
ACSM-EP Cardiovascular Physiology 5
What is the expected blood pressure response during a graded exercise test in a normotensive individual?