Jean Paul Fauchier

Interventricular and intraventricular dyssynchrony in idiopathic dilated cardiomyopathy. A prognostic study with Fourier phase analysis of radionuclide angioscintigraphy

OBJECTIVES The study evaluated the prognostic value of interventricular and intraventricular dyssynchrony in idiopathic dilated cardiomyopathy (IDC). BACKGROUND Biventricular pacing is an emerging treatment for patients with dilated cardiomyopathy and ventricular dyssynchrony. The prognostic values of interventricular and intraventricular dyssynchrony have not been previously compared. METHODS A total of 103 patients with IDC were studied. Left bundle branch block was present in 25% of patients. Equilibrium radionuclide angiography was performed and Fourier phase analyses were examined in both ventricles. Difference between the mean phase of left ventricle (LV) and right ventricle (RV) assessed interventricular dyssynchrony, and standard deviations (SDs) of the mean phase in each ventricle assessed intraventricular dyssynchrony. RESULTS The QRS duration was related to both interventricular and intraventricular dyssynchrony. A degradation of the hemodynamic status was associated with an increase in intraventricular dyssynchrony but not in interventricular dyssynchrony. With a follow-up of 27 +/- 23 months, 18 patients had a major cardiac event (7 cardiac deaths; 11 worsening, leading to heart transplantation). The SDs of the LV and RV mean phase and QRS duration were predictors of cardiac event (all p < 0.0001), but interventricular dyssynchrony was not. Among 13 univariate predictors of cardiac event, the only independent predictors were an increased SD of LV mean phase (p = 0.0004) and an increased pulmonary capillary wedge pressure (p = 0.009). CONCLUSIONS Intraventricular dyssynchrony evaluated with phase analysis of radionuclide angiography is an independent predictor of cardiac event in IDC. The prognosis is related to intraventricular rather than to interventricular dyssynchrony in IDC.

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.

Prognostic value of heart rate variability for sudden death and major arrhythmic events in patients with idiopathic dilated cardiomyopathy.

OBJECTIVE This study was designed to evaluate the prognostic value of heart rate variability for sudden death, resuscitated ventricular fibrillation or sustained ventricular tachycardia in patients with idiopathic dilated cardiomyopathy. BACKGROUND Previous studies have shown that heart rate variability could predict arrhythmic events and sudden death in postinfarction patients, but the prognostic value of heart rate variability for arrhythmic events or sudden death in patients with idiopathic dilated cardiomyopathy has not been established. METHODS Time and frequency domain analysis of heart rate variability on 24-h electrocardiographic (ECG) recording was assessed in 116 patients with idiopathic dilated cardiomyopathy (91 men, aged 51+/-12 years, left ventricular ejection fraction 34+/-12%). RESULTS Mean follow-up (+/-SD) was 53+/-39 months. Sixteen patients reached one of the defined study end-points (sudden death, resuscitated ventricular fibrillation or sustained ventricular tachycardia) during follow-up. Using multivariate analysis, only reduced standard deviation of all normal-to-normal intervals (SDNN) (p = 0.02) and ventricular tachycardia during 24-h ECG recording (p = 0.02) predicted sudden death and/or arrhythmic events. For SDNN, a cutoff level of 100 ms seemed the best for the risk stratification. CONCLUSIONS Decrease in heart rate variability is an independent predictor of arrhythmic events and sudden death in idiopathic dilated cardiomyopathy, whether the mechanism of sudden death is ventricular tachyarrhythmia or not.

Long-term prognostic value of time domain analysis of signal-averaged electrocardiography in idiopathic dilated cardiomyopathy

The aim of this study was to evaluate the long-term prognostic value of signal-averaged electrocardiography (SAECG) in idiopathic dilated cardiomyopathy (IDC). Time domain analysis of SAECG was assessed in 131 patients with angiographically confirmed IDC (age 52+/-12 years; 108 men; left ventricular ejection fraction 33+/-12%) using specific criteria in 44 patients with bundle branch block. Late potentials (LP) on SAECG were present in 27% of the patients. Patients with LP had a similar left ventricular ejection fraction and a similar left ventricular end-diastolic diameter than patients with a normal SAECG. With a follow-up of 54+/-41 months, 24 patients suffered cardiac death and 19 had major arrhythmic events (sudden death, resuscitated ventricular fibrillation, or sustained ventricular tachycardia). Patients with LP had an increased risk of all-cause cardiac death (RR 3.3, 95% confidence interval 1.5 to 7.5, p = 0.004) and of arrhythmic events (RR 7.2, 95% confidence interval 2.6 to 19.4, p = 0.0001). Using multivariate analysis, only LP on SAECG (p = 0.001), reduced SD of all normal-to-normal intervals (SDNN) (p = 0.002), increased pulmonary capillary wedge pressure (p = 0.005), and history of sustained ventricular tachyarrhythmia (p = 0.02) predicted cardiac death. A history of previous sustained ventricular tachyarrhythmia (p = 0.0001), reduced SDNN (p = 0.003), and LP on SAECG (p = 0.006) were the only independent predictors of major arrhythmic events. Results were not altered when considering separately patients with or without bundle branch block, or after exclusion of patients with a history of sustained ventricular tachyarrhythmia. This study is one of the first to suggest that LP on SAECG is an independent predictor of all-cause cardiac death and is of high interest for arrhythmia risk stratification in IDC.

Heart rate variability in severe right or left heart failure: the role of pulmonary hypertension and resistances

The decrease in heart rate variability (HRV) might be related to the hemodynamic status in heart failure. However, HRV in patients with severe isolated right heart failure has not been extensively studied.

Association Between Heart Rate-Corrected QT Interval and Coronary Risk Factors in 2,894 Healthy Subjects (The DESIR Study)

In the prospective Data from an Epidemiological Study on the Insulin Resistance Syndrome, 2,894 healthy subjects aged 30 to 64 years had determinations of fasting glucose, insulin, serum lipid and fibrinogen concentrations, blood pressures, body mass index, and waist-hip ratio, as well as tobacco and alcohol consumptions and physical activity. A 12-lead electrocardiogram with automatic measurement of the QT interval was recorded and the formula used for heart rate correction was based on the best-fit regression between QT and heart rate. The QT duration was influenced by glucose homeostasis in both sexes, and increased in men with physical activity; there was a dose-effect relation for men who smoked.

Diagnosis of arrhythmogenic right ventricular cardiomyopathy by Fourier analysis of gated blood pool single photon emission tomography

To evaluate the diagnostic performance of Fourier phase analysis of gated blood pool single-photon emission computed tomography (GBP SPECT) in arrhythmogenic right ventricular (RV) cardiomyopathy, 18 patients with confirmed arrhythmogenic RV cardiomyopathy underwent GBP SPECT and x-ray cineangiography. Results were compared with data obtained with GBP SPECT in 10 control subjects. This 3-dimensional method demonstrated good correlation with cineangiography for measurements of RV enlargement and extent of the disease; RV and left ventricular segments were analyzed with the same accuracy. Tomographic abnormalities were significant decreased RV ejection fraction, RV dilatation, nonsynchronized contraction of the ventricles, increased RV contraction dispersion, presence of segmental RV wall motion disorders and/or phase delays, and occasionally regional left ventricular abnormalities. RV-delayed phase areas were always present in our population. A scoring system with RV criteria was proposed to diagnose RV disease. Because Fourier analysis of GBP SPECT provides ventricular morphologic information for the right ventricle with the same accuracy as for the left ventricle, it may replace planar radionuclide studies. Therefore, this method is helpful in patients with a strong clinical suspicion of arrhythmogenic RV cardiomyopathy, and should be used as a screening method before right ventriculography.

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.

Ventricular dyssynchrony and risk markers of ventricular arrhythmias in nonischemic dilated cardiomyopathy: a study with phase analysis of angioscintigraphy.

FAUCHIER, L., et al .: Ventricular Dyssynchrony and Risk Markers of Ventricular Arrhythmias in Nonischemic Dilated Cardiomyopathy: A Study with Phase Analysis of Angioscintigraphy. Biventricular pacing is a new form of treatment for patients with dilated cardiomyopathy and ventricular dyssynchrony. Limited information is available regarding the relationship between ventricular dyssynchrony and risk markers of ventricular arrhythmias in idiopathic dilated cardiomyopathy (IDC). In 103 patients with IDC, Fourier phase analysis of both ventricles was performed from equilibrium radionuclide angiography (ERNA). The difference between the mean phase of the LV and RV was a measure of interventricular dyssynchrony, and the standard deviations of the mean phases in each ventricle measured intraventricular dyssynchrony. There were no significant differences in inter‐ and intraventricular dyssynchrony between patients with versus without histories of sustained VT or VF, nonsustained VT, abnormal signal‐averaged ECG, or induced sustained monomorphic VT. Dyssynchrony was not related to decreased heart rate variability (HRV). LV and interventricular dyssynchrony were weakly related to QT duration and QT dispersion. During a follow‐up of 27 ± 23  months , 21 patients had major adverse cardiac events (MACE), including 7 cardiac deaths, 11 progression of heart failure leading to cardiac transplantation, and 3 sustained VT/VF. The only independent predictors of MACE were an increased standard deviation of LV mean phase (P = 0.003), a decreased HRV (standard deviation of normal‐to‐normal intervals, P = 0.004), and histories of previous VT/VF (P = 0.03) or nonsustained VT (P = 0.04). In conclusion, left intraventricular dyssynchrony evaluated with ERNA was an independent predictor of MACE in IDC and was not related to usual risk markers of ventricular arrhythmias. This may have implications for resynchronization therapy and/or the use of implantable cardioverter defibrillators in IDC. (PACE 2003; 26[Pt. II]:352–356)