QT Interval Prolongation and Atypical Proarrhythmia: Monomorphic Ventricular Tachycardia with Trimebutine

A 59-year old woman was admitted at emergency for palpitation and dizziness. Medication history showed trimebutine 450 mg daily, because of meteorism, increased to 450 mg TID a week earlier. At admittance, sustained monomorphic ventricular tachycardia was interrupted by 100 mg intravenous lidocaine and a largely prolonged QTc (523 ± 12 ms) was seen. Discontinuation of trimebutine achieved normalisation of QTc (420 ± 10 ms, p<0.001). This is the first report in man to illustrate a probable proarrhythmic action of trimebutine. A weak inhibitory effect on both rapid and slow components of the delayed rectifier in guinea-pig ventricular myocytes calls for further investigations in human myocardial tissues. Trimebutine inhibition of Na + and Ca ++ channels in cardiac tissues of rabbits and guinea-pigs also call for further studies in human myocardial tissues.