Comparison of long-term outcome of alcoholic and idiopathic dilated cardiomyopathy.

AIMS: The outcome of alcoholic cardiomyopathy is thought to be better than idiopathic dilated cardiomyopathy if patients abstain from alcohol. The aim of this study was to compare the long-term clinical outcome of alcoholic and idiopathic dilated cardiomyopathy. METHODS AND RESULTS: Of 134 patients with dilated cardiomyopathy and normal coronary angiography, 50 had alcoholic cardiomyopathy; they were compared serially to 84 patients with idiopathic dilated cardiomyopathy. Left ventricular end-diastolic diameter, left ventricular ejection fraction and cardiac index, severity of ventricular arrhythmias, measurement of heart rate variability and results of signal-averaged ECG were similar in both groups. Although alcohol withdrawal was strongly recommended but observed in only 70% of patients with alcoholic cardiomyopathy, both groups had similar outcome in terms of cardiac death after follow-up treatment of 47+/-40 months. Multivariate analysis in the entire cohort demonstrated that increased pulmonary capillary wedge pressure (P=0. 003), alcoholism and lack of abstinence during follow-up (P=0.006) and decreased standard deviation of all normal-to-normal RR intervals (P=0.02) were independent predictors of cardiac death. CONCLUSION: In contrast with previous studies, patients with alcoholic cardiomyopathy did not have a better outcome than patients with idiopathic dilated cardiomyopathy. Alcoholism without abstinence was a strong predictor of cardiac death. This suggests that a more aggressive approach to alcohol cessation is needed in these patients.

Effect of verapamil on QT interval dynamicity.

Using measurements of QT/RR slopes with a computerized Holter system, QT interval dynamicity was evaluated in 19 patients with normal structural heart before and 2 months after oral treatment with verapamil prescribed for paroxysmal atrioventricular nodal reentrant tachycardia. Verapamil significantly shortened QT at low heart rates, mainly in the diurnal period, and this characteristic may explain, in part, the previously reported protective effect of verapamil against torsades de pointes.

Influence of duration and hour of recording on spectral measurements of heart rate variability.

UNLABELLED: Frequency-domain analysis of heart rate variability provides information about influences of autonomic nervous system on the heart and can be measured on short-term or long-term electrocardiogram recording. We compared heart rate variability on 24 h electrocardiogram recording with measurements of heart rate variability over shorter periods of 1 h and 12 h in order to determine the influence of duration and hour of recording on the heart rate variability parameters in the frequency domain. Heart rate variability was analyzed in 24 subjects with normal heart, with measurement of total power (Tot P), ULF, VLF, LF, HF and LF/HF ratio. Reference measurements over 24 h were compared with measurements over 4 periods of 1 h (2 AM-3 AM, 8 AM-9 AM, 2 PM-3 PM, 8 PM-9 PM) and over 4 periods of 12 h (2 AM-2 PM, 8 AM-8 PM, 2 PM-2 AM, 8 PM-8 AM). The correlations with measurements over 24 h were lower for the measurements over 1 h than for the measurements over 12 h. ULF had the lowest mean of correlation coefficients for measurements over 1 h and 12 h, whereas the other frequency bands had high correlations with measurements over 24 h. When using Bland and Altman method, only measurements over 2 AM-2 PM and 2 PM-2 AM periods were a reliable estimation of heart rate variability over 24 h. CONCLUSION: Spectral measurements of heart rate variability over 12 h have high correlations with measurements on 24 h. ULF is the parameter the most affected by the duration of the recording. Spectral measurements over 2 AM-2 PM and 2 PM-2 AM periods are reliable appreciations of heart rate variability over 24 h.

[Temporal and spectral analysis of heart rate variability in primary dilate cardiomyopathy: evaluation by case control study]. / Analyse temporelle et spectrale de la variabilité du rythme sinusal dans la cardiomyopathie dilatée primitive. Evaluation par une étude cas-témoin.

Temporal and spectral analysis of heart rate variability over 24 hours (HRV) was undertaken in 89 patients with primary dilated cardiomyopathy (DCM) confirmed by left ventriculography with normal coronary angiography and compared with 60 control subjects. The left ventricular ejection fraction was 35 +/- 12% in the DCM patients (71 men and 18 women: age 51 +/- 11 years). Clinical signs of cardiac failure were observed in 66% of patients, requiring medication in 62% of patients (diuretics: 47%, digitalis: 45% and ACE inhibitors: 33%). The HRV was significantly lower in the DCM patients than in the control group, even in the absence of clinical signs of cardiac failure. The global HRV was correlated to left ventricular fractional shortening (r = 0.5, p < 0.001) and peak oxygen consumption on exercise (r = 0.56, p < 0.01), but was independent of the degree of left ventricular dilatation, pulmonary capillary pressure and cardiac index. It was not significantly different in cases of sustained or non-sustained ventricular tachycardia on Holter ECG or in cases with late ventricular potentials on signal averaging of the surface ECG. During follow-up of 51 +/- 35 months, patients with decreased HRV on the global indices and those reflecting sympathetic activity had a much higher risk of cardiovascular death and of cardiac transplantation (p < 0.01). The authors conclude that HRV is decreased in DCM. This is mainly related to the degree of left ventricular dysfunction and is independent of the ventricular arrhythmogenic substrate. The HRV may also identify subgroups of patients with DCM at high risk of cardiovascular death or of haemodynamic decompensation requiring cardiac transplantation.

Effect of flecainide on heart rate variability in subjects without coronary artery disease or congestive heart failure.

Heart rate variability is a noninvasive indicator of autonomic nervous system activity. The role of the autonomic nervous system in the genesis of atrial or ventricular arrhythmias is now well established. Little is known about the effects of flecainide on heart rate variability in patients with normal heart structure, the main population receiving flecainide. This study was designed to evaluate the effects of flecainide on heart rate variability in patients without coronary artery disease or congestive heart failure. Time and frequency domain analysis of heart rate variability on 24-hour electrocardiogram recording were assessed in 40 patients with normal echocardiography and without evidence of coronary artery disease before and after 2 months of oral treatment with flecainide (321 +/- 57 mg/day) prescribed for Wolff Parkinson White syndrome with circus movement tachycardia. Flecainide significantly decreased all parameters of heart rate variability in the time domain (median delta% -10% to -25%) and in the frequency domain (median delta% -27% to -38%), including the markers of vagal activity. There was no correlation between plasma concentrations of flecainide and reduction in heart rate variability. It was concluded that in subjects without coronary artery disease or congestive heart failure, flecainide decreases all the measurements of heart rate variability and this decrease is not related to plasma concentrations of flecainide.

Effect of verapamil on heart rate variability in subjects with normal hearts.

Heart rate variability on 24-hour electrocardiographic recording was assessed in 23 patients without structural heart disease before and after 2 months of oral treatment with verapamil prescribed for paroxysmal atrioventricular nodal reentrant tachycardia. Verapamil had no significant effect on overall heart rate variability in the frequency domain, but it increased ultra low frequency power and decreased the low-frequency/high-frequency ratio, deemed to be a marker of sympathetic activity.

Heart rate variability in idiopathic dilated cardiomyopathy: characteristics and prognostic value.

OBJECTIVES: This study was designed to evaluate heart rate variability (HRV) in patients with idiopathic dilated cardiomyopathy (IDC), to determine its correlation with hemodynamic variables and ventricular arrhythmias and to evaluate its prognostic value in IDC. BACKGROUND: Previous studies have shown that HRV could predict arrhythmic events in patients after infarction, but the characteristics of HRV in IDC have not been fully established. METHODS: Time domain analysis of HRV on 24-h electrocardiographic (ECG) recording was performed in 93 patients with IDC, and results were compared with those in 63 control subjects. RESULTS: Patients with IDC, even those without congestive heart failure, had significantly lower values for HRV than those of control subjects. HRV was related to left ventricular shortening fraction (R = 0.5, p = 0.0001) and to peak oxygen uptake (R = 0.53, p = 0.01). HRV was not different in patients with runs of ventricular tachycardia or in patients with late potentials on the signal-averaged ECG. During a mean follow-up period (+/-SD) of 49.5 +/- 35.6 months, patients with reduced HRV had an increased risk of cardiac death or heart transplantation (p = 0.006). On multivariate analysis, cardiac events were predicted by increased left ventricular end-diastolic diameter (p = 0.0001), reduced standard deviation of all normal to normal RR intervals (p = 0.02) and increased pulmonary capillary wedge pressure (p = 0.04). CONCLUSIONS: Decreased HRV in patients with IDC is related to left ventricular dysfunction and not to ventricular arrhythmias. Analysis of HRV can identify patients with IDC who have an increased risk of cardiac death or heart transplantation.