Oncology Certified Nurse (OCN) Nursing Practice Test

Which is a common sign accompanying tachycardia in cardiac tamponade?

1. Weak apical pulse

2. High blood pressure

3. Bradycardia

4. Shortness of breath

The correct answer is: Weak apical pulse

In cardiac tamponade, the accumulation of fluid in the pericardial space exerts pressure on the heart, limiting its ability to fill appropriately during diastole. This impaired filling can lead to a drop in stroke volume, which in turn results in a compensatory mechanism where the heart rate increases, leading to tachycardia. A weak apical pulse is common in this scenario because while the heart is beating faster, the reduced stroke volume can lead to a pulse that feels weak or diminished when palpated, specifically at the apex of the heart. This reflects the insufficient blood being pumped out with each heartbeat, characteristic of cardiac tamponade. Signs like high blood pressure, bradycardia, and even shortness of breath may occur due to various conditions or complications but are not as directly associated with the physiological changes caused by cardiac tamponade as a weak apical pulse. In fact, cardiac tamponade often presents with low blood pressure due to compromised cardiac output. Therefore, recognizing a weak apical pulse is crucial in understanding the manifestations of tachycardia in this critical setting.