A 38-year-old patient, with no past history of interest, diagnosed with depressive syndrome and on treatment with venlafaxine (75 mg - 150 mg - 150 mg v.o.) and alprazolam (1-2 mg v.o. /8 h). She consulted her primary care physician after an episode of oppressive chest pain, non-radiating and without vegetative cortex, which fluctuated in intensity during the day but did not subside despite rest. An electrocardiogram (ECG) was performed showing sinus tachycardia at around 120 bpm with repolarisation alterations.
He was transferred to hospital and admitted to the Intensive Care Unit, where a new ECG confirmed persistent sinus tachycardia with very diffuse repolarisation alterations, as well as negative T waves in the anterior face and a prolongation of the QT space of around 500 msg. He was diagnosed as having Acute Coronary Syndrome and conventional treatment was started with double antiplatelet therapy (acetylsalicylic acid 100 mg v.o./24 h and clopidogrel 75 mg v.o./24 h), anticoagulation (enoxaparin 80 mg s.c./24 h) and intravenous infusion of nitroglycerin at 10 ml/hour. When sinus tachycardia continued, treatment with low doses of beta-blockers (atenolol 25 mg v.o./12 h) was started.

The absence of alterations in cardiac markers prompted a new ECG which indicated regional alterations in contractility. A coronary angiographic study showed a normal left ventricle with an ejection fraction of 65% and a normal segmental analysis, showing epicardial coronary arteries without significant angiographic stenosis, ruling out the existence of active coronary artery disease.
Given the suspicion that the cardiovascular effects could be caused by venlafaxine, the drug was withdrawn and treatment was started with sertraline 50 mg v.o./day, decreasing the dose of nitroglycerine to 5 ml/h until its subsequent discontinuation. The patient progressed adequately and continued treatment with sertraline and atenolol, shortening the QT interval and maintaining heart rates of around 80 bpm, with ECG evolution towards normalisation of repolarisation.

