Comprehensive non-invasive assessment of electrocardiographic abnormalities and cardiac arrhythmias in patients with genetically confirmed mitochondrial diseases.

BACKGROUND: There is limited data on cardiac arrhythmias and ventricular repolarization and dispersion abnormalities in patients with mitochondrial diseases (MitD). METHODS: Consecutive 40 patients with genetically proven MitD and 35 healthy controls were studied. Among other examinations all subjects underwent 24-h Holter recording and 12­lead electrocardiography (ECG) with corrected QT (QTc), QT dispersion (QTd), Tp-e and Tp-e/QT ratio assessment. RESULTS: Patients with MitD were 55.4 ± 15.7 years old, the disease duration was 18.5 ± 10.3 years, presented 6 clinical syndromes while mitochondrial and nuclear DNA type of mutation was present in 40 and 60% of cases, respectively. In MitD more frequently 1st degree atrioventricular block and intraventricular conduction defects were observed and also QRS complex duration was increased. Mean values of QTc (p = 0.001), QTd (p = 0.02), Tp-e (p < 0.00001) and Tp-e/QT (p < 0.00001) were significantly higher in MitD than in controls. Correlations between disease duration and PR interval duration (p = 0.003) and Creatine Kinase MB isoenzyme activity (p = 0.02) were found. No differences in depolarization and dispersion parameters were observed according to type of mutation or dominant clinical syndromes. In addition to supraventricular extrasystoles, nonsustained supraventricular tachycardias occurred more frequently in MitD (in 45.0 vs 14.3%, p = 0.0004). Ventricular arrhythmias were rare and observed almost exclusively in subjects with mitochondrial DNA mutation. CONCLUSIONS: In contrast to healthy controls, in MitD patients intraventricular, repolarization and dispersion disturbances were more frequently observed. In addition to bradyarrhythmias observed in some defined MitD syndromes, supraventricular rather than ventricular arrhythmias are more common.

High incidence of venous thromboembolism but not of coronary artery disease in granulomatosis with polyangiitis in first years after diagnosis.

Objectives: Granulomatosis with polyangiitis (GPA), previously known as Wegener's granulomatosis, is one of antineutrophil cytoplasmic autoantibody (ANCA) - associated vasculitis. In patients with GPA an increased incidence of venous thromboembolism (VTE), mainly during active disease, has been described. The aim of the present study was to assess the incidence of VTE and its relation with classic risk factors for atherosclerosis, presence of coronary artery disease (CAD), echocardiographic parameters and laboratory findings in GPA patients. Methods: The group of consecutive patients with GPA were followed in the study. In all patients echocardiography and laboratory tests were performed. Results: Ninety six patients with GPA were followed for mean 3 years. In 16 patients (16.6%) VTEs occurred in association with GPA, of which 56% occurred 6 months before or one year after diagnosis of GPA. Classic risk factors for atherosclerosis were present in 77 patients (80.2%) at some moment during follow-up. In patients with VTE there were larger right ventricle diameter (p=0.041) and higher right ventricle systolic pressure (p=0.022) observed. VTEs occurred significantly less frequently in patients treated with cyclophosphamide (p=0.049). In this study group VTE occurred more frequently than CAD: 16 (16.7%) vs. 4 (4.2%); p=0,0049. Patients with VTE were younger than those with CAD (p=0.053) and had higher levels of ANCA-PR 3 (p=0.016). Conclusions: Patients with granulomatosis with polyangiitis in first years after diagnosis have higher risk of venous thromboembolism than coronary artery disease. This finding is probably related to hypercoagulability induced by the disease and its therapy.