Q. Abolition of Arrhythmias by Exercise?
The induction of arrhythmias by exercise is well recognized, but the abolition of ectopic activity is less commonly appreciated. The mechanism responsible for this include rapid heart rate, which increases the relative time during the refractory period, providing a measure of overdrive suppression and decreased automaticity of the Purkinje system, associated with rapid stimulation. It is common to see young, apparently healthy subjects who have PVCs at rest but not during exercise. Also in CAD patients, many PVCs are abolished by exercise, just as they are in normally, therefore, this finding does not ensure that the patient is free of disease.