How does Bradycardia affect the filling time of ventricles?

Bradycardia, characterized by a slower than normal heart rate, has a direct impact on the filling time of the ventricles. When the heart rate decreases, the time allocated for ventricular filling during diastole is effectively extended. This results in a longer duration for the ventricles to fill with blood, allowing for increased stroke volume up to a certain point.

While it may seem counterintuitive that a slower heart rate could enhance filling time, it is crucial to consider that the period during which the heart is relaxed and filling with blood directly correlates with the heart's rhythm. In the case of bradycardia, the prolonged diastolic phase offers the ventricles more time to accommodate blood entering from the atria before the next contraction occurs. Thus, the relationship between a reduced heart rate and increased filling time is well-established in cardiovascular physiology.

Other listed options either suggest no impact or insufficient alteration of systolic function, which does not capture the physiological dynamics of how bradycardia influences the cardiac cycle, particularly during diastolic filling.