What are common causes of bradycardia?

Bradycardia, defined as a slower than normal heart rate (typically less than 60 beats per minute), can arise from several underlying causes. The correct answer highlights three major contributors: heart block, medication effects, and aging.

Heart block refers to a condition where the electrical signals in the heart are partially or fully obstructed. This disruption can lead to a reduced heart rate because the signals that stimulate the heart to beat may not reach the appropriate areas effectively, leading to a slower heartbeat.

Medication effects play a significant role as well. Various medications, particularly those affecting the cardiovascular system, such as beta-blockers, calcium channel blockers, and certain antiarrhythmics, can have a bradycardic effect. These drugs are often prescribed for conditions such as hypertension or arrhythmias, which can inadvertently result in a lower heart rate.

Aging is another intrinsic factor that contributes to bradycardia. As individuals age, the heart's electrical system may undergo structural changes that can lead to a slower conduction of impulses. This natural decline in heart function with age can manifest as bradycardia in older adults.

In contrast, the other options presented include factors that do not commonly cause bradycardia. Increased physical activity typically raises heart