RESULTS OF BIVENTRICULAR ENDOMYOCARDIAL BIOPSY IN SURVIVORS OF CARDIAC-ARREST WITH APPARENTLY NORMAL HEARTS

Seventeen young patients (10 males and 7 females, aged 14 to 38 years, mean 26.4) with out overt organic heart disease, who had been resusci tated from sudden cardiac arrest and referred to our institution durin g the period 1984 to 1993 for diagnostic evaluation and electrophysiol ogic study-guided antiarrhythmic therapy, were studied. Patients under went noninvasive (electrocardiography, echocardiography [2-dimensional and Doppler], and magnetic resonance imaging) and invasive (left vent ricular [LV], right ventricular [RV], and coronary angiography, ergono vine testing, electrophysiologic study, and biventricular endomyocardi al biopsy) cardiac studies. Six to 8 biopsy fragments per patient were processed for histology and electron microscopy and read by a patholo gist blinded to clinical data. Antiarrhythmic drug testing included am iodarone, propafenone, and metoprolol. A cardioverter-defibrillator wa s implanted in patients with persistently inducible sustained ventricu lar tachycardia or ventricular fibrillation. Sequential cardiac biopsy specimens were obtained in patients with active myocarditis undergoin g immunosuppressive treatment. Periodic 3-month follow-ups included ec hocardiography and Holter monitoring. Two groups of patients were dist inguished by invasive and noninvasive examinations: group I consisted of 9 patients with entirely normal parameters; group II consisted of 8 patients with structural, nonspecific cardiac abnormalities. In this latter group, mild to moderate dilatation aml hypokinesia of the left ventricle were documented in 4 patients, concentric LV hypertrophy was seen in 3 patients, and RV dysfunction was noted in 1 patient. Histol ogic examination was abnormal in all patients and revealed specific le sions in 65% of them; LV biopsy specimens allowed a diagnosis in 3 of 7 myocarditic patients with normal RV histology. An active lymphocytic myocarditis was observed in 7 patients, hypertrophic cardiomyopathy i n 3 patients, RV dysplasia in 1 patient, and nonspecific cardiomyopath ic changes in 6 patients. At 38-month follow-up, the mortality rate wa s 29% (all deaths were sudden). Biventricular endomyocardial biopsy ma y identify diagnostic lesions in young survivors of cardiac arrest wit h apparently normal hearts. In some patients LV biopsies revealed myoc arditis when RV biopsies were normal.