So, the passive filling and atrial kick
occur simultaneously, resulting in shortened LV filling time and decreased preloading of LV.
Some children tolerate atrial fibrillation for months at a time with no hemodynamic changes, while others may require the atrial kick
to sustain their cardiac output.
Studies in patients without MI have demonstrated that loss of atrial kick
decreases left ventricular output by 15 to 20 percent.