Emergency Medical Technician (EMT) Practice Test

What happens when someone has pericardial tamponade?

1. High blood pressure and rapid heart rate

2. Low blood pressure and rapid heart rate

3. Low blood pressure; muffled heart sound; weak pulse

4. High blood pressure; muffled heart sound; strong pulse

The correct answer is: Low blood pressure; muffled heart sound; weak pulse

When someone has pericardial tamponade, the accumulation of fluid in the pericardial sac exerts pressure on the heart, restricting its ability to fill properly during diastole. This condition leads to a classic triad of symptoms known as Beck's triad, which includes low blood pressure, muffled heart sounds, and a weak pulse. Low blood pressure occurs due to the impaired cardiac output caused by insufficient filling of the heart, particularly the right ventricle. Muffled heart sounds can be attributed to the fluid dampening the sounds that would typically be heard through a stethoscope. Furthermore, a weak pulse reflects the decreased volume of blood being pumped effectively by the heart, leading to reduced perfusion. In contrast, the other options suggest different combinations of signs that do not accurately represent the physiological changes associated with pericardial tamponade. Therefore, the presence of low blood pressure, muffled heart sounds, and a weak pulse correctly identifies the clinical picture seen in this condition.