Left and right ventricular morphology, function and late gadolinium enhancement extent and localization change with different clinical presentation of acute myocarditis Data from the Italian multicenter study on MYocarditis (ITAMY)

AIMS: Poor data exist about cardiac magnetic resonance (CMR) findings in a large sample of acute myocarditis with different clinical presentations (heart failure, arrhythmias, and infarct-like presentation). METHODS: Five hundred and forty-three in-patients with a clinical suspected of acute myocarditis confirmed by CMR were enrolled. The clinical indications to perform CMR were chest pain and/or dyspnea and/or palpitations, or effort intolerance/malaise in the last month; elevated troponin and/or new ventricular dysfunction, and/or new ECG abnormalities; and suspected inflammatory cause. CMR examination has permitted to identify epicardial and mid-layer distribution of late gadolinium enhancement (LGE) and to quantify left ventricular (LV) and right ventricular (RV) volumes, and ejection fraction. RESULTS: According to the main clinical pattern of presentation, three groups were categorized: heart failure (heart failure group; 35 patients, 6.4%), arrhythmias (arrhythmias group; 24 patients, 4.4%), and infarct-like (infarct-like group, 484 patients, 89.2%).Heart failure group and arrhythmias group had significantly higher LV volumes and number of LGE segments and lower LV and RV ejection fraction than the infarct-like group.Epicardial LGE in the LV inferolateral wall was the most frequent LGE location in each group. Mid-layer LV septal LGE showed a greater prevalence in the heart failure (52%) and arrhythmias (47%) groups than in the infarct-like group (27%, P < 0.0001). CONCLUSION: In patients with CMR-detected acute myocarditis, heart failure, and arrhythmias have both a higher prevalence of LV and RV dysfunction, segments with LGE, and septal LGE with respect to the infarct-like group.