Tako-tsubo syndrome following nortriptyline overdose

Tako-tsubo syndrome (TTS) refers to the apical ballooning of the left ventricle observed when angiographic ventriculography is performed in patients presenting with electrocardiographic changes suggestive of acute coronary syndrome (new transient ST-segment deviation (>0.05 mV) or T-wave inversion (>0.2 mV)), mild elevation of cardiac markers, but normal coronary arteries at the angiogram.

A 54-year-old woman developed the characteristic features of TTS 44 hours following nortriptyline overdose. The admission ECG showed increased QRS duration rapidly reversible after sodium bicarbonate infusion. There was a minimal increase in troponin I level. The ECG performed at the time of chest pain revealed deeply negative T waves in leads I, II, III, aVF, V1 to V6 and remained abnormal at 5 weeks follow-up. In contrast, a complete recovery of left ventricular function was observed within one week.

The pathophysiology of TTS, a variant of myocardial stunning, is still incompletely understood but could be related to sympathetic overstimulation. The possibility of TTS following toxic exposure is discussed.