What is associated with the smallest stroke volume in an ECG rhythm strip?

The option related to the smallest stroke volume in an ECG rhythm strip is associated with premature ventricular contractions (PVCs). In the setting of PVCs, the heart's normal rhythm is interrupted by an early contraction originating in the ventricles.

This early contraction can lead to inefficient heart filling because the ventricles do not have enough time to fill properly before the next beat. As a result, the volume of blood pumped out with each contraction, or stroke volume, can be significantly reduced. This is particularly true if PVCs occur in a frequency that does not allow adequate recovery time for effective filling of the cardiac chambers, leading to diminished stroke volume.

In contrast, normal sinus rhythm maintains a coordinated heartbeat with regular filling and ejection of blood, leading to an adequate stroke volume. Atrial fibrillation also results in reduced stroke volume but typically does not reduce it as dramatically as PVCs due to the loss of atrial contraction, which contributes to ventricular filling. Ventricular tachycardia can lead to decreased stroke volume through rapid heart rates that may compromise filling time; however, it often generates higher stroke volumes initially.

Thus, the association of premature ventricular contraction with the smallest stroke volume underscores the impact of timing and efficiency of cardiac contractions on overall cardiac