Malignant vasovagal syncope: A therapeutic challenge. Report of four cases.

Four patients, two men and two women aged 20 to 32 years, had malignant vasovagal syncopes defined by ventricular arrest of more than four seconds' duration. The vasovagal symptoms were reproduced by exercise testing in one patient and by a 60 degrees head-up tilt test in the other three. A beta-blocking agent was effective in the first patient but failed to prevent malignant vasovagal syncope during the tilt test in two of the other three patients. The tilt test became negative under disopyramide in one of these patients and under diphemanil in the other. No recurrences were recorded after a mean follow-up of three years although the treatment was discontinued in all four cases. These data and those reported in the literature suggest that implantation of a pace maker is not appropriate as first-line therapy for malignant vasovagal syncope.