MYOCARDITIS: VIRUS OR DESMOSOME?

Abstract

Abstract Patient Profile Female, 56 yo, arterial hypertension, FH of autoimmune diseases, no history of sudden death. Medical History: • At the age of 46: Hospitalized for chest pain. Coronary angiography: negative. Diagnosis: myocardial ischemia with normal coronary arteries. • 2018: Hospitalized again for angina. ECG showed low voltages, flat T–waves in the inf–lat. leads. Coronary angiography: negative. Biopsy Mild hypertrophy and cytoplasmic vacuolization, minimal increase in interstitial fibrosis, no necrosis or inflammatory infiltrates. Mild nonspecific cardiomyopathy. Viral DNA test positive for HHV–6. Serology: HHV–6 in blood (neg), IgG HHV–6 (pos), IgM (neg). Diagnosis: myocarditis due to HHV–6. • San Camillo Cardiomyopathy Center: Echocardiogram: basal ant–lat. hypokinesia, EF 60%. Therapy: Bisoprolol 3.75 mg, Ramipril 5 mg, Ranolazine 1000 mg. MRI: basal transmural ant–lat. and subepicardial lateral LGE. Oedema and hypokinesia coexists. Subacute myocarditis. MRI at 1 year: mild left ventricular dilation, EF 60%, meso–subepicardial LGE in the ant–lat and inf mid–basal regions without oedema. Serial Holter ECGs: frequent polymorphic ventricular ectopics, couplets, and runs. CPET: normal exercise capacity, pVO2 19.4 (ml/min)/kg (90%). Genetic testing VUS in DSC, probably pathogenic, and VUS in ABCC9, PKP2, DSP (2 mutations) with uncertain clinical significance. • In 2022: Readmitted for angina. Elevated Troponin levels. Coro CT angiography: negative. MRI: EF 45%, akinesia of the apex and apical lat. wall; diffuse LGE and edema. Pericardial effusion. Patient refused biopsy. Discharged after recovery (EF 52%) with the diagnosis of recurrent myocarditis. Empagliflozin added. • Follow up. ECG: progression of repolarization abnormalities (TWI in V1–V3 + inf.–lat. leads). Biopsy: fibroadipose replacement, no necrosis or inflammatory infiltrates. Chronic myocarditis and sequels. Viral tests: negative. CPET and stress echo: VO2peak 20.7 (ml/kg)/min (88%), normal work capacity. Very rare monomorphic PVCs. EF 50%, preserved contractile reserve. Conclusions Diagnosis of left dominant arrhythmogenic cardiomyopathy with a typical pattern for hot phases of myocardial inflammation. The first episode could have been triggered by a viral infection on a predisposing genetic substrate. Nadolol 40 mg x2 was introduced. The possibility of ICD implantation was discussed, and patient refused. A six–month follow–up was planned. Family screening results were negative.