Prognostic significance of left ventricular aneurysms with normal global function caused by myocarditis

To evaluate the prognosis of left ventricular (LV) aneurysms with normal global function caused by myocarditis.

LV aneurysms may result from idiopathic or viral myocarditis. The prognosis of inflammatory LV aneurysms when associated with a normal cardiac function is unknown.

Among 353 patients with a histologic diagnosis of myocarditis, 12 (3.3%) had single or multiple localized LV aneurysms (length, 10.6 +/- 3.1 mm; width, 7.4 +/- 4.2 mm) with normal cardiac function. Presenting symptoms were ventricular tachycardia (VT) in nine patients and unexplained chest pain in three. All patients underwent laboratory tests and noninvasive and invasive cardiac examinations, including biventricular endomyocardial biopsy.

In all patients, LV endomyocardial biopsy specimen showed a lymphocytic myocarditis with focal intense myocytolysis or damage of intramural vessels, whereas right ventricular biopsy was diagnostic for myocarditis only in three. Serologic study suggested a viral infection in 3 patients and an immunologic disorder in 2, although it was negative in 7. Treatment included antiarrhythmics in 9 patients with VT, ss-blockers in 1 with chest pain, and immunosuppression (prednisone and azathioprine for 5 months) in 4 with active myocarditis (2 with chest pain and 2 with VT). At intermediate-term follow-up (mean, 53 months; range, 12 to 120 months), LV function was persistently normal in all patients, with an LV aneurysm occlusion being observed in two patients. All patients were asymptomatic, with no VT recurrence or major clinical events. None required implantable electrical devices or a surgical intervention.

LV aneurysms with normal global function caused by myocarditis are an uncommon benign entity in which major therapeutic regimens are usually unnecessary.