Drug-induced notched T waves

A typical, counter-clockwise, atrial flutter with an alternating atrioventricular conduction block. b Electrocardiogram recorded 5 min after intravenous administration of ibutilide. Besides successful conversion to sinus rhythm, QTc prolongation (460 ms) can be observed along with a positive deflection in the downward slope of the T waves in leads V2–V5. c Electrocardiogram 2 weeks after admittance to the emergency department. LQTS type 2 is caused by loss of function of the KCNH2 (hERG) gene, which codes for the rapid delayed rectifier potassium channel (IKr) and plays an important role in the repolarisation of the myocardial cell. Schwartz, PJ; Crotti, L. QTc behavior during exercise and genetic testing for the long-QT syndrome.