Registered Cardiovascular Invasive Specialist (RCIS) Practice Test

What condition is indicated by pulsus paradoxus?

1. Right heart failure

2. Myocardial infarction

3. Cardiac tamponade

4. Aortic stenosis

The correct answer is: Cardiac tamponade

Pulsus paradoxus is a physiological phenomenon characterized by a significant drop in blood pressure during inhalation. This finding is most commonly associated with cardiac tamponade, a condition where fluid accumulates in the pericardial sac surrounding the heart. This fluid buildup exerts pressure on the heart, particularly affecting its ability to fill adequately during diastole. In the case of cardiac tamponade, when a person inhales, the negative pressure in the thoracic cavity can further compress the heart, leading to a decrease in stroke volume and, consequently, a drop in blood pressure. This extreme variation in blood pressure measurements during the respiratory cycle is a hallmark sign of cardiac tamponade. Other conditions listed may exhibit various signs and symptoms related to heart function but do not typically manifest pulsus paradoxus. For instance, right heart failure and myocardial infarction may present with fluid overload or compromised perfusion, respectively, but they do not specifically cause this respiratory-related blood pressure variation. Aortic stenosis involves narrowing of the aortic valve, which affects blood flow from the heart but, again, is not characterized by pulsus paradoxus. Thus, the association of pulsus paradoxus with cardiac tamponade is well-established in clinical literature, making it the