Biomedical subjects

Renato Bragato

Publications and source records attributed to Renato Bragato.

3 recordsLinked to original sources

PubMed2006

Low-K+ dependent QT prolongation and risk for ventricular arrhythmia in anorexia nervosa.

BACKGROUND: QT prolongation and ventricular arrhythmia have been proposed as the mechanism for sudden death in anorexia nervosa. The prevalence and the cause of QT prolongation remain controversial. OBJECTIVES: 1) to evaluate ventricular repolarization in patients with anorexia; 2) to evaluate factors that may influence repolarization, with focus on electrolyte plasma levels and heart rate. METHODS: 29 patients with anorexia, age 22 +/- 5 years, BMI 13.8 +/- 1.5 were compared to 14 control female subjects, age 23 +/- 2 years, BMI 20.7 +/- 1.1. QT interval and QT dispersion were measured. Whenever a low potassium (<3.5 mEq/l) was found, ECG was repeated after normalization of serum levels. Heart rate and its variability in the frequency domain (LF/HF ratio) were evaluated. RESULTS: Three patients (10.3%) showed severe hypokalemia (K(+) levels <2.0 mEq/l). In 2 patients, QT was severely prolonged (QT(c) 600 and 670 msec) and in one case associated with ventricular arrhythmia. QT(c) after K(+) plasma levels normalization was 392 +/- 25 in anorexia vs. 407 +/- 19 msec in controls, p = 0.08. Heart rate was 55 +/- 11 in anorexia vs. 66 +/- 8 beats per minute (BPM) in controls, p = 0.002. The LF/HF ratio was 1.79 +/- 1.35 in anorexia and 3.66 +/- 2.64 in controls, p = 0.006. CONCLUSIONS: QT interval is usually normal in patients with anorexia. QT prolongation and ventricular arrhythmia may develop in the setting of severe hypokalemia, exposing patients to high risk of sudden cardiac event. Resting heart rate is lower in anorexia than in controls with the spectral indices of sympatho-vagal balance indicating a prevalence of vagal activity.

Adult↗

PubMed2006

Clinical predictors of marked improvement in left ventricular performance after cardiac resynchronization therapy in patients with chronic heart failure.

BACKGROUND: Previous studies have shown that cardiac resynchronization therapy (CRT) improves cardiac performance and decreases mortality and hospital admission rates. However, it is not yet clear which patients will benefit from the procedure the most. The purpose of the study was to identify the pre-implant characteristics that better predict which patients will have the best outcome after CRT. METHODS: In this observational study, 156 patients were studied with echocardiography and a 6-minute walking test at baseline and 12 months after CRT. RESULTS: After CRT, we observed an increase in left ventricular ejection fraction (+29.6%, P < .0001), a decrease in left ventricular end systolic volume (-26.4%, P < .0001), in the proportion of patients with grade 2-4 mitral regurgitation (from 47.1% to 34.0%, P = .002), and with NYHA functional class III-IV (from 83.2% to 11.6%, P < .0001), an increase in exercise tolerance (+31.1%, P < .0001). Sixty-two patients had a marked increase in left ventricular ejection fraction (> 10 units); the only independent predictor of a marked effect of CRT was the nonischemic etiology of heart failure. In patients with ischemic cardiomyopathy, the benefit on ejection fraction correlates inversely with the extension of the ischemic damage. CONCLUSIONS: CRT improves left ventricular function and exercise tolerance in the long term. The nonischemic etiology of the cardiomyopathy is the only independent predictor of a marked effect of CRT; this is probably due to the absence of ischemic, nonviable scar tissue in these patients.

Adrenergic beta-Antagonists↗

PubMed2002

[Mitral insufficiency].

Over the past 15 years, outcome of patients with severe mitral insufficiency is significantly improved. This may be due to concomitant advances in many fields of medicine such as a more effective diagnosis and left ventricular function monitoring by means of echocardiography, development of useful guidelines and advances in valve reconstruction techniques. We will discuss some aspects of mitral anatomy, pathophysiology, echocardiographic diagnosis and the proper timing for surgical intervention.

Heart Ventricles↗