Alterações ecocardiográficas em pacientes com ataxia de Friedreich / Echocardiographic abnormalities in patients with Friedreich ataxia

Fundamentos: a ataxia de Friedreich é a mais frequente das ataxias hereditárias, caracterizando-se, fundamentalmente, por um curso progressivo e elevada prevalência de comprometimento cardíaco. Resulta da síntese anormal da frataxina, proteína abundante em mitocondrias e relacionada com a produção de energia. Além de comum, o comprometimento cardíaco é uma causa frequênte de morte. Há aproximadamente dez anos, tornou-se possível o diagnóstico molecular, o que levou a uma melhor caracterização dessa enfermidade, Nesse período ocorreram também mudanças significativas nos critérios de avaliação ecocardiográfica, bem como na qualidade das imagens obtidas por esse método diagnóstico. Esses fatores podem ter levado a mudanças na prevalência das alterações ecocardiográficas encontradas na ataxia de Friedreich. Objetivo: Deteminar a prevalência das alterações ecocardiográficas, principalemnte da geometria do ventriculo esquerdo...

Eficácia do sotalol nas arritmias ventriculares idiopáticas com origem em trato de saída de ventrículo direito / Efficacy of Sotalol in Patients With Idiophatic Right Ventricular Arrhythmias

PURPOSE--To evaluate the effects of sotalol in patients (pts) with idiophatic ventricular arrhythmias (VT) from right ventricular outflow tract. METHODS--Eighteen pts with VT were enrolled (five with monomorphic repetitive ventricular tachycardia - MRVT). Pts were submitted to a double-blind crossover randomized study (placebo vs. 320 mg/po/d/sotalol; four weeks each), after a wash-out control period. Holter recording were recorded in control and placebo and drug periods. Eligible pts have > 50/h isolated ventricular premature beats (VPB) in control, with or without paired VPB or nonsustained VT (NSVT- > 3 beats, > 100bpm). Drug efficacy criteria was: > 75//reduction in isolated VPB and > 90//of paired VPB or NSVT. The effects of the drug on uncorrected QT interval was evaluated and also on circadian rhythm of VT through the hourly pNN50/VPB ratios. Values are given as mean +/- SD. Three recordings were compared by using paired Student's ®t® test. Statistical significance was assumed for p < 0.05. RESULTS--Differences between control and placebo were NS. Drug was effective in 61//of pts, reducing the 3 types of ET (VPB: placebo = 23.508 +/- 34.537; drug: 975 +/- 1357; paired placebo = 443 +/- 587; drug = 9 +/- 20). The drug was evaluated in 4 pts with MRVT, reducing all ectopic events, with efficacy of 60//over VPB and paired and 80//over NSVT (VPB: placebo = 52.639 +/- 42.207; drug: 1631 +/- 2062; paired: placebo = 796 +/- 754; drug: 20 +/- 30; NSVT: placebo = 4287 +/- 6343; drug: 9 +/- 11). Mean QT interval was 0.40 +/- 0.01s in control and 0.50 +/- 0.04s in the drug period, with no correlation between duration and efficacy. Sotalol modified the circardian rhythm of VPB in the non-responders group, mainly during the morning. CONCLUSION--Sotalol was effective in control of VT, mainly the MRVT. Its effect on VPB circadian rhythm may independently contribute to the overall efficacy profile and myocardial protective effect of this drug