Echocardiographic evaluation of cardiac function in patients with myotonic dystrophy - is the right ventricular dysfunction observed? One academic center experience.

Introduction: The aim of this study was to analyze echocardiographic parameters of the right and left ventricular function in patients with genetically confirmed myotonic dystrophy (DM).

Clinical rationale for the study: Cardiac complications remain a major cause of morbidity and mortality in DM; however, up until now, data on the right ventricular function is scarce.

Material and methods: We analyzed echocardiograms of 83 consecutive DM patients referred to our center for comprehensive clinical neurological and cardiac assessment and compared them to echocardiograms in 46 controls. Patients with diagnosed coronary artery disease or with significant valvular lesions were not included.

Results: The study group consisted of 83 DM patients (41 females; aged 15-69 years), including 42 with DM type 1 (DM1) (13 females; aged 15-64 years) and 41 with DM type 2 (DM2) (28 females; aged 18-69 years). 44% of DM2 and 4.8% of DM1 patients suffered from hypertension, 4.9% and 12% had type 2 diabetes. TAPSE and RV S' medians were lower in DM than in controls (p < 0.001 and p = 0.01, respectively), with lower values in DM1 than in DM2 (p = 0.009 and p = 0.02). TAPSE < 17mm was observed only in DM patients (8.4%, p = 0.049). RV S' < 9.5 cm/s was found only in DM1, not in DM2. Right ventricular systolic dysfunction defined as TAPSE < 17 mm or RV S' < 9.5 cm/s was observed in 12.1% DM patients (19% DM1 vs. 4.9% DM2, p = 0.09) and 2.2% of controls (p = 0.1). Left ventricular systolic dysfunction defined by LVEF < 50% was found in 3.6% of DM patients and was threefold less frequent than right ventricular systolic dysfunction (p = 0.04). Diastolic dysfunction was found in 24.1% DM patients (21% DM1 and 27% DM2, p = 0.75), and in 6.6% controls (p = 0.02), more frequently in older patients with hypertension. Systolic parameters of both ventricles were similar in patients with and without comorbidities. The echocardiographic findings did not correlate with the disease duration or neurological status.

Conclusions: Right ventricular systolic function is impaired in DM patients, especially in DM1, irrespectively of neurological impairment, disease duration, and presence of comorbidities. In our study, left ventricular systolic dysfunction was rare and less prevalent than right; however, future studies with larger cohorts of patients are needed. Our findings underline the need for close cardiac follow-up with detailed echocardiographic assessment of both ventricles in DM.