Long follow-up study in patients with prior myocarditis by radionuclide methods.

Ten patients with previous myocarditis were evaluated to determine cardiac conditions by T1-201 myocardial perfusion imaging and stress radionuclide ventriculography during the follow-up of 18-102 (average 56) months; the results were compared with those from ten sex- and age-matched controls. Exercise capacity by supine bicycle ergometer was reduced in patients with myocarditis. Their resting left ventricular ejection fraction (LVEF) was 57.5% +/- 3.9%, similar to that of controls. LVEF response to stress in myocarditis was abnormal with an increment of end-systolic volume, while in the controls LVEF increased significantly during stress. Seven of the eight patients with an abnormal ejection fraction response had constant T1-201 perfusion defects. This study indicates that latent left ventricular dysfunction is present in patients with prior myocarditis and that nuclear study is useful for long-term follow-up.