Ventricular fibrillation induced by transesophageal atrial pacing in hypertrophic cardiomyopathy

Sudden death is a rather frequent occurrence in patients withhypertrophic cardiomyopathy, yet the mechanism is uncertainin most cases. We describe a case of an 18 years old patientwith a family history of hypertrophic cardiomyopathy and suddendeath in whom ventricular fibrillation could be repeatedly inducedby means of transesophageal atrial stimulation with 1 : 1 AVconduction at a rate of 200 beats min^-1 and prevented by pharmacologicaldepression of AV node. The not particularly high ventricularrate at which VF occurred could suggest that in hypertrophiccardiomyopathy a major role in favouring VF induction is playedby the electro-physiological properties of the myocardium andthat sudden death can occur as a consequence of different atrialtachyarrhythmias.