Dynamic Change of Left Ventricular Mechanics in Patients with Acute Myocarditis with Preserved Left Ventricular Systolic Function: A 2-Year Follow-up Study.

Objective: Acute myocarditis mimics acute coronary syndrome due to its clinical course and presentation. This study aimed to evaluate left ventricular longitudinal and circumferential functions during the acute phase and late phase of acute myocarditis with preserved left ventricular ejection fraction using 2-dimensional speckle tracking echocardiography.

Methods: Forty-one consecutive acute myocarditis patients with preserved left ventricular ejection fraction confirmed by cardiac magnetic resonance imaging underwent 2-dimensional speckle tracking echocardiography within the first week of hospital admission. Findings were compared with age and sex-matched 40 healthy controls. Left ventricular mechanics of the study group were reevaluated by 2-dimensional speckle tracking echocardiography during follow- up (23.85 ± 6.65 months later).

Results: Myocardial lesions with late gadolinium enhancement on cardiac magnetic resonance imaging were mostly localized in the subepicardial layer (91.40%) and commonly observed in the inferolateral wall (42.94%). Consistent with the cardiac magnetic resonance imaging findings, 2-dimensional speckle tracking echocardiography showed the localization of the involved myocardial segments with prominent impairment in global longitudinal peak systolic strain and global circumferential strain of the inferolateral wall of the left ventricle. In the acute phase, global longitudinal peak systolic strain (-17.32 ± 2.02 vs -20.59 ± 2.38) and global circumferential strain (-22.33 ± 2.27 vs -24.85 ± 3.19) were found to be lower in patients with acute myocarditis compared to healthy controls (both P < .001). While global circumferential strain was improved in the late phase compared with the acute phase (from -22.28 ± 2.32 to -22.90 ± 2.65; P = .003). Global longitudinal peak systolic strain was not significantly changed during follow-up (from -17.30 ± 2.09 to -17.62 ± 2.19; P = .072).

Conclusion: Subtle left ventricular systolic function impairment can be detected by the 2-dimensional speckle tracking echocardiography technique in patients with acute myocarditis with preserved left ventricular ejection fraction and improvement in circumferential function could be observed during follow-up.