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

Objectives: To evaluate the prognosis of left ventricular (LV) aneurysms wi th normal global function caused by myocarditis. Background: LV aneurysms may result from idiopathic or viral myocarditis. T he prognosis of inflammatory LV aneurysms when associated with a normal car diac function is unknown. Methods: 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 symptom s 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 biops y. Results: In all patients, LV endomyocardial biopsy specimen showed a lympho cytic myocarditis with focal intense myocytolysis or damage of intramural v essels, whereas light ventricular biopsy was diagnostic for myocarditis onl y in three. Serologic study suggested a viral infection in 3 patients and a n immunologic disorder in 2, although it was negative in 7. Treatment inclu ded antiarrhythmics in 9 patients with VT, beta -blockers in 1 with chest p ain, 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 ob served in two patients. All patients were asymptomatic, with no VT recurren ce or major clinical events. None required implantable electrical devices o r a surgical intervention. Conclusions: LV aneurysms with normal global function caused by myocarditis are an uncommon benign entity in which major therapeutic regimens are usua lly unnecessary.