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Dominique Babuty

Publications and source records attributed to Dominique Babuty.

At least 19 recordsLinked to original sources
PubMed2006

Outcome after implantation of a cardioverter-defibrillator in patients with Brugada syndrome: a multicenter study.

BACKGROUND: Brugada syndrome is an arrhythmogenic disease characterized by an increased risk of sudden cardiac death (SCD) by ventricular fibrillation. At present, an implantable cardioverter-defibrillator (ICD) is the recommended therapy in high-risk patients. This multicenter study reports the outcome of a large series of patients implanted with an ICD for Brugada syndrome. METHODS AND RESULTS: All patients (n=220, 46+/-12 years, 183 male) with a type 1 Brugada ECG pattern implanted with an ICD in 14 centers between 1993 and 2005 were investigated. ICD indication was based on resuscitated SCD (18 patients, 8%), syncope (88 patients, 40%), or positive electrophysiological study in asymptomatic patients (99 patients, 45%). The remaining 15 patients received an ICD because of a family history of SCD or nonsustained ventricular arrhythmia. During a mean follow-up of 38+/-27 months, no patient died and 18 patients (8%) had appropriate device therapy (10+/-15 shocks/patient, 26+/-33 months after implantation). The complication rate was 28%, including inappropriate shocks, which occurred in 45 patients (20%, 4+/-3 shocks/patient, 21+/-20 months after implantation). The reasons for inappropriate therapy were lead failure (19 patients), T-wave oversensing (10 patients), sinus tachycardia (10 patients), and supraventricular tachycardia (9 patients). Among implantation parameters, high defibrillation threshold, high pacing threshold, and low R-wave amplitude occurred, respectively, in 12%, 27%, and 15% of cases. CONCLUSIONS: In this large Brugada syndrome population, a low incidence of arrhythmic events was found, with an annual event rate of 2.6% during a follow-up of >3 years, in addition to a significant risk of device-related complications (8.9%/year). Inappropriate shocks were 2.5 times more frequent than appropriate ones.

Adult↗
PubMed2006

Different criteria of cardiac resynchronization therapy and their prognostic value for worsening heart failure or major arrhythmic events in patients with idiopathic dilated cardiomyopathy.

There are still controversies about pertinent criteria for cardiac resynchronization therapy (CRT) and prophylactic indications for biventricular cardioverter-defibrillators, particularly in idiopathic dilated cardiomyopathy (IDC). This study compared several criteria for resynchronization therapy in IDC among those of several completed trials. In 201 patients with IDC, the relative risk for (1) death from heart failure (HF) or heart transplantation and (2) sudden death or sustained ventricular tachyarrhythmia were calculated separately according to the inclusion criteria of the Multisite Stimulation in Cardiomyopathy (MUSTIC), InSync, Multicenter InSync Randomized Clinical Evaluation (MIRACLE), Pacing Therapies for Congestive Heart Failure (PATH-CHF), Comparison of Medical Therapy, Pacing, and Defibrillation in Heart Failure (COMPANION), and CONTAK studies. The percentage of patients meeting the criteria ranged from 6% for those of MUSTIC to 23% for those of CONTAK. In a follow-up of 51 +/- 42 months, 28 patients died (15 from progressive HF, 13 from sudden death), 20 underwent heart transplantation, and 12 had sustained ventricular tachyarrhythmia. Relative risks of worsening HF ranged from 3.14 (95% confidence interval [CI] 1.41 to 6.99, p = 0.005) for the MIRACLE criteria to 4.63 (95% CI 1.76 to 12.2, p = 0.0019) for the MUSTIC criteria. Only the CONTAK criteria were significantly associated with a risk for major arrhythmic events (2.65, 95% CI 1.19 to 5.95, p = 0.018). Arrhythmic events constituted 16% of all cardiac events for the MUSTIC patients, 11% for InSync patients, 31% for PATH-CHF patients, 36% for MIRACLE patients, 38% for COMPANION patients, and 42% for CONTAK patients. In conclusion, in IDC, the less restrictive criteria for CRT were associated with the greatest risk for arrhythmic events. In contrast, patients with the MUSTIC criteria for CRT mainly had a risk for worsening HF and may not benefit from biventricular cardioverter-defibrillators.

Adult↗
PubMed2006

Progressive cardiac conduction defect is the prevailing phenotype in carriers of a Brugada syndrome SCN5A mutation.

INTRODUCTION: Loss-of-function mutations in the SCN5A gene encoding the cardiac sodium channel are responsible for Brugada syndrome (BS) and also for progressive cardiac conduction disease (inherited Lenègre disease). In an attempt to clarify the frontier between these two entities, we have characterized cardiac conduction defect and its evolution with aging in a cohort of 78 patients carrying a SCN5A mutation linked to Brugada syndrome. METHODS AND RESULTS: Families were included in the study if a SCN5A mutation was identified in a BS proband and if at least two family members were mutation carriers. Sixteen families met the study criteria, representing 78 carriers. Resting ECG showed a spontaneous BS ECG pattern in 28 of 78 (36%) gene carriers. Intraventricular conduction anomalies were identified in 59 of 78 gene carriers including complete (17) or incomplete (24) right bundle branch block, right bundle branch block plus hemiblock (6), left bundle branch block (1), hemiblock (1), and parietal block (10). PR and QRS duration were longer in the gene carrier cohort in comparison with their relatives carrying no mutation. Finally, in the gene carrier cohort conduction defect progressively aggravated with aging leading in five occasions to pacemaker implantations. CONCLUSION: The present study shows that the most common phenotype of gene carriers of a BS-type SCN5A mutation is progressive cardiac conduction defects similar to the Lenègre disease phenotype. In consequence, we propose that carriers of a SCN5A mutation need a clinical and ECG follow-up because of the risk associated with severe conduction defects.

Adolescent↗
PubMed2005

QT dispersion in nonischemic dilated cardiomyopathy. A long-term evaluation.

BACKGROUND: In idiopathic dilated cardiomyopathy (IDC), the predictive value of QT dispersion is still under debate. AIMS: This study assessed the role of QT dispersion for the long-term risk of cardiac death and of major arrhythmic events in IDC. METHODS AND RESULTS: In 162 patients with IDC (age 52+/-12 years), the QT interval on a 12-lead ECG was measured manually. QT dispersion was evaluated with QT range and QT standard deviation, for both QT and QTc (Bazett formula). With a follow-up of 53+/-41 months, QT dispersion was not a predictor of cardiac death in univariate or in multivariate analysis, and was of similar value for patients with or without bundle branch block. Using multivariate analysis, increased pulmonary capillary wedge pressure (p=0.003), decreased heart rate variability (Standard deviation of all NN intervals, p=0.01) and non-sustained ventricular tachycardia (NSVT) (p=0.03) were predictors of cardiac death. Sudden death and/or major arrhythmic events were independently predicted by NSVT (p=0.005), decreased heart rate variability (p=0.01) and late ventricular potentials on signal averaged ECG (p=0.02). CONCLUSION: This study confirms the poor prognostic value of QT dispersion in patients with IDC. Other methods to assess repolarization abnormalities need to be evaluated in such patients.

Adult↗
PubMed2005

Potential cost savings by telemedicine-assisted long-term care of implantable cardioverter defibrillator recipients.

Home monitoring (HM) of cardioverter defibrillators (ICD) with its automated wireless remote data access, may decrease the rate of patient visits. This study examined the potential cost savings for the long-term care of ICD assisted by HM. A French database including 502 patients from 6 university hospitals was used. Costs of conventional follow-up (FU) of ICD were calculated without, and compared with the expected cost of FU with HM. Calculations included number of visits, including physician's fees, electrocardiograms, and specific ICD surveillance, and transportation costs. The mean distance between home and institutions performing follow-ups was 69 +/- 57 km. For each visit, a mean overall cost of 215 dollars was calculated, including 121 dollars for transportation and 94 dollars for medical services. HM may obviate up to 2 visits per year. Over the 5 years of expected life of the device, the decrease in costs for FU visits was estimated at 2,149 dollars. With an additional cost of 1,200 dollars for the HM system, saving began after a mean FU of 33.5 months. The time to onset of cost saving by HM ranged between 17.4 months for patients living >150 km from the medical facility to 52.2 months for those living <50 km away. It is concluded that the HM may considerably reduce the overall costs of ICD FU by saving on transportation cost, particularly when the distance between home and medical facility is >100 km.

Cost Savings↗
PubMed2004

Segmental wall motion abnormalities in idiopathic dilated cardiomyopathy and their effect on prognosis.

There is considerable variability in segmental wall motion abnormalities and in the prognosis of idiopathic dilated cardiomyopathy (IDC). Radionuclide ventriculography with Fourier analysis was performed in 107 patients with angiographically proved IDC. Amplitude analysis located the wall motion abnormalities. Using phase analysis in the left and right ventricles, the interventricular delay between the mean phase of the right and left ventricles was used to assess interventricular dyssynchrony and SDs of the mean phase in each ventricle was used to assess intraventricular dyssynchrony. Hypokinesis was global in 56 patients (52%) and localized in the anteroseptal wall in 34 (32%), the inferior wall in 12 (11%), the anteroseptal and inferior walls in 2 (2%), and the lateral wall in 3 (3%). Patients with localized wall motion abnormalities had larger left ventricular (LV) end-diastolic diameters (70 +/- 9 vs 66 +/- 8 mm, p = 0.009) and lower LV ejection fractions (25 +/- 9% vs 31 +/- 12%, p = 0.005). Intraventricular dyssynchrony was lower in patients with global hypokinesis (SD of LV mean phase 67 +/- 35 vs 48 +/- 22 ms, p = 0.002). With a follow-up of 27 +/- 23 months, increased SD of the LV phase (p = 0.005), decreased right ventricular ejection fraction (p = 0.006), decreased LV ejection fraction (p = 0.04), and localized wall motion abnormality (p = 0.009) were independent predictors of cardiac death or worsening heart failure leading to heart transplantation. Thus, segmental wall motion abnormalities are frequent in IDC and are associated with severe systolic dysfunction and a worse prognosis.

Cardiomyopathy, Dilated↗
PubMed2004

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

BACKGROUND: 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. AIMS: This study compared HRV in patients with congestive heart failure (CHF) and in patients with isolated right heart failure. METHODS: Time and frequency domain analysis of HRV on 24-h ECG recording was assessed in 15 healthy subjects and in two groups of patients with severe heart failure awaiting heart or heart/lung transplantation. These were 15 patients with CHF due to idiopathic dilated cardiomyopathy (IDC) and 10 patients with isolated right heart failure due to primary pulmonary hypertension (PPH). RESULTS: Measurement of HRV were significantly decreased in both groups of patients compared with the control group. Patients with IDC had higher pulmonary capillary wedge pressure than patients with PPH (P=0.04) but lower pulmonary artery pressure and lower pulmonary vascular resistance (PVR) (P<0.0001). However, all the measurements of HRV were significantly lower in patients with IDC than in patients with PPH (range 22-77%, P<0.05 to P<0.01). None of the HRV measurements correlated with filling pressure measurements. CONCLUSIONS: The increase in pulmonary vascular resistance in heart failure is not the main causal factor behind a decrease in HRV.

Adult↗
PubMed2003

Reliability of QRS duration and morphology on surface electrocardiogram to identify ventricular dyssynchrony in patients with idiopathic dilated cardiomyopathy.

Using Fourier phase analysis of equilibrium radionuclide angiography in both ventricles, inter- and intraventricular delays were correlated with QRS morphology and duration in 103 patients with idiopathic dilated cardiomyopathy. We found that left bundle branch block on the left axis may reflect a high intra-left ventricular dyssynchrony. A precise evaluation of the dyssynchrony appears useful because a high proportion of patients with incomplete bundle branch block, left anterior hemiblock, or "normal" QRS exhibit a marked intra-LV dyssynchrony and may respond to cardiac resynchronization therapy.

Bundle-Branch Block↗
PubMed2003

Ca2+ current-mediated regulation of action potential by pacing rate in rat ventricular myocytes.

OBJECTIVE: Pacing rate regulates the duration of the cardiac action potential (AP). It also regulates the decay kinetics of the L-type Ca(2+) current (I(Ca-L)) which occurs via modulation of Ca(2+)-dependent inactivation. We investigated whether and how this latter process contributes to frequency-dependent (FD) changes in the AP waveform in rat ventricular cells. METHODS: We recorded APs using a microelectrode technique in rat papillary muscles, and using the whole-cell current patch-clamp technique in single rat ventricular cells. RESULTS: The AP duration (APD) was increased by high rates encompassing the physiological range (0.1-5.7 Hz) in both papillary muscles and single cells. This prolongation was accompanied by concomitant depolarisation (approximately 7 mV at 5.7 Hz) of the membrane potential (MP) in papillary muscles. Equivalent artificial depolarisation of the MP enhanced the FD prolongation in single cells. The FD prolongation was enhanced in presence of the K(+) current blocker 4-aminopyridine (5 mmol/l), and decreased in absence of extracellular Ca(2+). It was antagonised by Ca(2+) channel blockers (Co(2+), nifedipine, nitrendipine) and decreased by use of high EGTA (10 vs. 0.5 mmol/l EGTA) or BAPTA (20 mmol/l) in the patch-pipette. It was prevented by ryanodine or thapsigargin, two drugs that reduce or abolish SR-Ca(2+) function. CONCLUSION: I(Ca-L) contributes to the FD modulation of the AP, which occurs following a sudden change in cardiac frequency in rat ventricular cells. This highly dynamic physiological process is related to SR-Ca(2+) release and occurs through beat-to-beat adaptation of Ca(2+)-dependent inactivation of I(Ca-L).

4-Aminopyridine↗
PubMed2003

Management of atrial tachyarrhythmias: benefits of pacemaker diagnostics.

The aim of this prospective multicenter study was to assess the clinical benefits of the Selection (Vitatron) pacemaker diagnostic functions (AF 1.0) in the management of AF. Forty patients (71 +/- 9 years of age), with documented AF and conventional pacing indications, received a Selection. The AF 1.0 function of the pacemaker was programmed to document the AF burden, onset, daily distribution, duration, premature atrial beats before onset, and mode of onset of the last 12 episodes for AF episodes exceeding 180 beats/min. By comparing patients' symptoms records, patient conventional assessment at follow-up and AF 1.0 data, the investigators evaluated the usefulness of AF 1.0 in AF management at 3- and 6-month follow-ups. Usefulness was defined as a change in arrhythmia management prompted by the disclosure of AF 1.0 data. AF recurrences were recorded in 71% of the follow-ups with symptoms reported by patients in only 16%. Thirty-nine percent of therapeutic changes based on conventional assessment were confirmed by AF 1.0 data, and in 61% of instances, the initial changes were modified by AF 1.0 data. Changes included pacing parameters in 56% of cases, AF prevention with pacing algorithms in 37%, and medical treatment in 7%. All investigators indicated that AF 1.0 was useful in all patients. The AF 1.0 diagnostic functions offered a unique documentation of AF in asymptomatic patients, and allowed therapeutic adjustments impossible otherwise.

Aged↗
PubMed2003

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.

Cardiomyopathy, Dilated↗