Certified Cardiovascular Technician Practice Exam

Which of the following is a potential cause of PVCs?

1. Increased physical activity

2. Stimulants like cocaine and caffeine

3. Increased blood pressure

4. Low metabolic rate

The correct answer is: Stimulants like cocaine and caffeine

Premature Ventricular Contractions (PVCs) are extra heartbeats that originate from the ventricles and disrupt the regular heart rhythm. One of the well-established causes of PVCs is the consumption of stimulants, such as cocaine and caffeine. These substances can accelerate heart rate and induce excitability in cardiac tissue, leading to arrhythmias including PVCs. When caffeine is consumed, it stimulates the central nervous system, which can result in increased adrenergic activity, potentially causing the cardiac muscle to fire erratically. Similarly, cocaine can dramatically increase heart rate and disrupt normal conduction pathways within the heart, contributing to the development of PVCs. This is why stimulants are recognized as factors that can lead to these premature contractions. The other options, while they may be related to cardiovascular health, do not directly cause PVCs in the same manner that stimulants do. Increased physical activity, for example, is generally associated with beneficial adaptations in heart function, while increased blood pressure alone may not directly lead to PVC formation in the absence of other risk factors. A low metabolic rate does not specifically trigger PVCs either, as these contractions primarily arise from electrical disturbances in the heart rather than metabolic processes alone.