When Does Atrial Kick Occur

Cardiac Physiology Atrial contraction, or “atrial kick,” occurs at the end of diastole just before the closing of the mitral valve and after passive flow has reached the diastasis. Normally, greater than 75% of flow occurs during the passive portion of diastole.

Is atrial kick normal?

The atrial kick contributes a significant volume of blood toward ventricular preload (approximately 20%). At normal heart rates, the atrial contractions are considered essential for adequate ventricular filling.

What causes a loss of atrial kick?

The atrial kick may be absent due to underlying medical conditions affecting atrial systole. In atrial fibrillation and atrial flutter, the cardiac muscle fibers of the atrium contract asynchronously due to multiple or asynchronous pacemakers. These conditions can diminish the atrial contraction in two ways.