What effect does bradycardia have on cardiac output in a post-MI patient?

Bradycardia, defined as a slower than normal heart rate, can significantly impact cardiac output, especially in patients who have experienced a myocardial infarction (MI). Cardiac output (CO) is calculated using the formula CO = heart rate (HR) × stroke volume (SV). In the case of bradycardia, the reduced heart rate typically leads to a decrease in overall cardiac output because the heart is beating less frequently.

In a post-MI patient, the heart muscle may already be compromised due to damage from the infarction, which may affect its ability to pump effectively (reduced stroke volume). If bradycardia occurs in this context, the combination of a reduced heart rate and potentially reduced stroke volume likely leads to insufficient blood flow to meet the body’s metabolic needs.

Furthermore, while stroke volume may compensate to some extent with increased filling due to a longer diastolic period (the time between heartbeats when the heart fills with blood), the heart rate's significant reduction in bradycardia can overwhelm this compensatory mechanism. Thus, the overall effect is a decrease in cardiac output, leading to reduced oxygen delivery to tissues, which is especially critical after an MI. Therefore, the answer reflecting this physiological interaction is that br