Abnormal QT interval variability in patients with hypertrophic cardiomyopathy: can syncope be predicted?

We sought to determine QT variability pattern in patients with hypertrophic cardiomyopathy (HCM) and its relationship with the risk of syncope. QT interval variability was assessed from 24-hour Holter monitoring in 10 HCM patients with history of syncope, 10 HCM patients without history of syncope, and 10 healthy subjects. QT variability was higher in patients with HCM, in particular in those with history of syncope, than in healthy controls.

Heart rate variability as a measure of autonomic nervous system function in anorexia nervosa.

Background And Hypothesis: Alteration in sympathovagal balance may be a mechanism of increased cardiovascular mortality and sudden death of patients with anorexia nervosa. This study was undertaken to characterize cardiac autonomic control in patients with anorexia nervosa by means of heart rate variability analysis.

Methods: Heart period variability by 24-h Holter recording was evaluated in 13 young women with anorexia nervosa, 10 constitutionally thin women, and 10 women of normal weight.

Power spectral analysis of heart period variability in hypertensive patients with left ventricular hypertrophy.

This study aimed to characterize sympathovagal balance by heart period power spectrum analysis in hypertensive patients with echocardiographic evidence of left ventricular hypertrophy. Twenty ambulatory patients (11 men and 9 women), aged 50 +/- 10 years, with established essential hypertension and echocardiographic left ventricular hypertrophy, performed 24-h blood pressure monitoring and electrocardiogram Holter recording on 2 consecutive days. Twenty age- and sex-matched normal subjects comprised the control group.

Influence of reversible segmental left ventricular dysfunction on heart period variability in patients with one-vessel coronary artery disease.

Objectives: This study evaluated the relation between reversible segmental left ventricular dysfunction and frequency domain measures of heart period variability in patients with coronary artery disease.

Background: Heart period variability is frequently reduced in patients with coronary artery disease. However, the mechanisms of this reduction are still unclear.

[Effects of coronary angioplasty on heart rate variability explored in the domain of time and frequency in patients with one-vessel coronary disease].

Background: Heart period variability is frequently reduced in patients with coronary artery disease. Although the mechanism for this reduction is still unclear, it seems to reflect alterations in cardiac autonomic control. In this study we have evaluated the relation between reversible segmental left ventricular dysfunction and time and frequency domain measures of heart period variability in patients with coronary artery disease.