Which heart condition can lead to an increased resting heart rate?

• A. Bradycardia
• B. Atrial septal defect
• C. Heart failure
• D. Aortic regurgitation

Answer: (C)

Heart failure is a condition that can lead to an increased resting heart rate. This increase occurs as a compensatory mechanism in response to the heart's reduced ability to pump blood effectively. When the heart is not functioning optimally, the body attempts to maintain adequate blood flow to vital organs by increasing the heart rate. This can lead to tachycardia, or an elevated resting heart rate, as the heart works harder to meet the metabolic demands of the body.

In heart failure, the body perceives a state of low cardiac output, prompting the autonomic nervous system to accelerate heart rate. This is often accompanied by neurohormonal activation, where the release of catecholamines and other hormones further stimulates the heart to beat faster. Thus, an increased resting heart rate is a common clinical finding in patients with heart failure, reflecting the underlying pathophysiological changes.

The other conditions listed typically do not lead to an increased resting heart rate in the same way. For instance, bradycardia is characterized by a slower heart rate, while conditions such as atrial septal defect and aortic regurgitation may have different hemodynamic effects that do not necessarily result in tachycardia as a primary symptom.