NCIt definition : A constellation of signs and symptoms which may include syncope, fatigue, dizziness,
and alternating periods of bradycardia and atrial tachycardia, which is caused by
sinoatrial node dysfunction.;
Alternative definition : CTCAE: A disorder characterized by a dysrhythmia with alternating periods of bradycardia
and atrial tachycardia accompanied by syncope, fatigue and dizziness.;