Resting bradycardia may also predispose to Atrial or ventricular ectopy (including couplets and bursts of nonsustained ventricular tachycardia); pauses after ectopic beats do not exceed 4 seconds Wandering supraventricular pacemaker Other ECG findings that may occur include First-degree atrioventricular (AV) block (in up to one third of athletes) Second-degree AV block (mainly type I); this finding occurs during rest and disappears with exercise High-voltage QRS with inferolateral T-wave changes (reflecting LV hypertrophy) Deep anterolateral T-wave inversion Incomplete right bundle branch block However, third-degree AV block is abnormal and should be investigated thoroughly.