Limited clinical utility of endomyocardial biopsy in patients presenting with ventricular tachycardia without apparent structural heart disease

To determine the cardiac pathology underlying ventricular tachyarrhythmias, endomyocardial biopsy was performed in 14 patients, 10 men and 4 women, with a mean age of 40 years (range 17–63) and no apparent structural heart disease, presenting with high‐density symptomatic nonsustained ventricular tachycardia (VT) (n = 4), sustained VT (n = 6), and ventricular fibrillation (n=4). The absence of coronary or valvular heart disease was documented by cardiac catheterization. The mean left ventricular ejection fraction was 56±10%. Noninvasive assessment of the ventricular arrhythmia was made in all patients with Holter monitoring and/or exercise testing, while invasive evaluation with programmed electrical stimulation was performed in 13 patients. Biopsy findings included subendocardial and interstitial fibrosis in 7 patients, and monocytes containing periodic acid Schiff (PAS) positive vacuoles in 1 patient; biopsy was normal in 6 patients. There was no relationship between the presence or absence of pathologic abnormalities on biopsy and left ventricular ejection fraction, presenting or induced arrhythmias, or prognosis. Pathologic evidence supporting a specific treatable diagnosis was not present in any biopsy. Drugs to suppress spontaneous (3 patients) or induced (8 patients) VT were instituted, while 2 patients were not treated. In 1 patient who was resuscitated from out‐of‐hospital cardiac arrest an automatic defibrillator was implanted. In 24.6 months of mean follow‐up there was 1 nonfatal arrhythmia recurrence, 1 noncardiac death, and 1 sudden death in a patient with fibrosis on biopsy, an ejection fraction of 45%, and both inducible and spontaneous sustained VT suppressed with an antiarrhythmic agent. We conclude that endomyocardial biopsy in patients presenting with VT and no coronary or valvular heart disease can be normal, rarely demonstrates a specific treatable diagnosis, and thus has limited clinical utility.