Ludivine Wissocque

Incidence and predictors of sudden death, major conduction defects and sustained ventricular tachyarrhythmias in 1388 patients with myotonic dystrophy type 1

Aims To describe the incidence and identify predictors of sudden death (SD), major conduction defects and sustained ventricular tachyarrhythmias (VTA) in myotonic dystrophy type 1 (DM1). Methods and results We retrospectively enrolled 1388 adults with DM1 referred to six French medical centres between January 2000 and October 2013. We confirmed their vital status, classified all deaths, and determined the incidence of major conduction defects requiring permanent pacing and sustained VTA. We searched for predictors of overall survival, SD, major conduction defects, and sustained VTA by Cox regression analysis. Over a median 10-year follow-up, 253 (18.2%) patients died, 39 (3.6%) suddenly. Analysis of the cardiac rhythm at the time of the 39 SD revealed sustained VTA in 9, asystole in 5, complete atrioventricular block in 1 and electromechanical dissociation in two patients. Non-cardiac causes were identified in the five patients with SD who underwent autopsies. Major conduction defects developed in 143 (19.3%) and sustained VTA in 26 (2.3%) patients. By Cox regression analysis, age, family history of SD and left bundle branch block were independent predictors of SD, while age, male sex, electrocardiographic conduction abnormalities, syncope, and atrial fibrillation were independent predictors of major conduction defects; non-sustained VTA was the only predictor of sustained VTA. Conclusions SD was a frequent mode of death in DM1, with multiple mechanisms involved. Major conduction defects were by far more frequent than sustained VTA, whose only independent predictor was a personal history of non-sustained VTA. ClinicalTrials.gov no: NCT01136330.Aims To describe the incidence and identify predictors of sudden death (SD), major conduction defects and sustained ventricular tachyarrhythmias (VTA) in myotonic dystrophy type 1 (DM1). Methods and results We retrospectively enrolled 1388 adults with DM1 referred to six French medical centres between January 2000 and October 2013. We confirmed their vital status, classified all deaths, and determined the incidence of major conduction defects requiring permanent pacing and sustained VTA. We searched for predictors of overall survival, SD, major conduction defects, and sustained VTA by Cox regression analysis. Over a median 10-year follow-up, 253 (18.2%) patients died, 39 (3.6%) suddenly. Analysis of the cardiac rhythm at the time of the 39 SD revealed sustained VTA in 9, asystole in 5, complete atrioventricular block in 1 and electromechanical dissociation in two patients. Non-cardiac causes were identified in the five patients with SD who underwent autopsies. Major conduction defects developed in 143 (19.3%) and sustained VTA in 26 (2.3%) patients. By Cox regression analysis, age, family history of SD and left bundle branch block were independent predictors of SD, while age, male sex, electrocardiographic conduction abnormalities, syncope, and atrial fibrillation were independent predictors of major conduction defects; non-sustained VTA was the only predictor of sustained VTA. Conclusions SD was a frequent mode of death in DM1, with multiple mechanisms involved. Major conduction defects were by far more frequent than sustained VTA, whose only independent predictor was a personal history of non-sustained VTA. ClinicalTrials.gov no: NCT01136330.

Pregnancy in women with an implantable cardioverter-defibrillator: is it safe?

AIMS To describe obstetric/neonatal and cardiac outcomes for a cohort of women carrying implantable cardioverter-defibrillators (ICDs) during pregnancy. METHODS AND RESULTS All women in routine follow-up at our institution for ICD implantation who became pregnant between 2006 and 2013 were included in this study. All ICDs were pre-pectoral devices with bipolar endocardial leads. Obstetric/neonatal and cardiac outcomes were assessed during pregnancy and post-partum. Twenty pregnancies were conceived by 12 women carrying ICD devices, 14 of which resulted in live births and none in maternal death. Seven of these women had structural cardiomyopathies and five had channelopathies. No device-related complications were recorded. Twelve shocks (nine transthoracic and three from ICDs) were experienced during pregnancy by two women, one of whom miscarried shortly afterwards at 4 weeks gestation. One stillbirth, three miscarriages and one termination were recorded for women with long QT syndrome, repaired tetralogy of Fallot and repaired Laubry-Pezzi syndrome, respectively. Intrauterine growth restriction, low birth weight, and neonatal hypoglycaemia were recorded in four, three, and five pregnancies, respectively. CONCLUSIONS Pregnancy had no effect on ICD operation and no evidence was found to link ICD carriage with adverse pregnancy outcomes, although one miscarriage may have been induced by ICD shock therapy. A worsening of cardiac condition occurs in specific cardiac diseases and β-blocker therapy should be continued for all women carrying ICDs in pregnancy as the benefits outweigh the risks of taking this medication.

Right Ventricular Pacing With Mechanical Dyssynchrony Causes Apoptosis Interruptus and Calcium Mishandling

BACKGROUND Mechanical dyssynchrony associated with rapid pacing induces cardiac cell stress and myocardial apoptotic pathway activation that has been implicated in the pathophysiology of left ventricular (LV) dysfunction. Effects of dyssynchrony per se are not fully understood. The objective of our study was to test whether ventricular dyssynchrony would elicit myocardial alterations in LV calcium handling regulation and cell survival or apoptosis signalling in right ventricular-paced swine. METHODS Implantation of pacemaker was performed under anaesthesia. Endocardial bipolar screw lead was inserted into the right jugular vein and positioned either in the right atrium or at the right ventricular (RV) apex. Swine were paced at 150 beats per minute for 3 weeks. RESULTS Compared with right atrial pacing, RV pacing led to abnormal LV sarcoplasmic reticulum calcium uptake (315 ± 65 vs 155 ± 55 nmol/min/mg, P < 0.05) and LV calcium-handling protein expression, ie, 35% reduction in ryanodine receptor 2, 25% decline in sarcoplasmic reticulum Ca(2+) ATPase, 70% increase in Na(+)/Ca(2+) exchanger, and 10% increase in phospholamban. RV pacing also elicited activation of LV apoptotic cascades without nuclear apoptosis. So-called interrupted apoptosis was the result of increased expression of X-linked inhibitor of apoptosis protein. Apoptosis and calcium mishandling were documented in absence of depressed heart function (ejection fraction 62 ± 8% vs 57 ± 12%, in right atrial- and RV-paced hearts, respectively, P > 0.05). CONCLUSIONS Slow rate RV pacing causes mechanical dyssynchrony and profound LV alterations in both apoptotic pathways and calcium handling in the early stages of pacing-induced cardiomyopathy.

Validation of an Organizational Management Model of Remote Implantable Cardioverter-Defibrillator Monitoring Alerts

Background—Implantable cardioverter-defibrillators (ICDs) are a standard means of sudden cardiac death prevention. Compared with ambulatory visits, remote monitoring (RM) of ICD recipients has improved the quality of health care and spared its resources. Few studies have addressed the organization of RM. We optimized and validated our institutional model of RM organization for ICD recipients. Methods and Results—This observational study of 562 ICD recipients compared 2 RM periods consisting of iterative, qualitative, and quantitative (1) device diagnostic evaluations by nurses and cardiologists; and (2) selected decisional trees. The main study end points were the professional interventions prompted by, and times allocated to, RM alerts. During the first period, 1134 alerts occurred in 427 patients (286 patient-year), of which 376 (33%) were submitted to cardiologists’ reviews, compared with, 1522 alerts in 562 patients (458 patient-year), of which 273 (18%) were submitted to cardiologists’ reviews during the second period (P<0.001). An intervention was prompted by 73 of 376 (19.4%) alerts in the first versus 77 of 273 (28.2%) in the second period (P=0.009). The mean time to manage an alert was 4 minutes 31 s in the first versus 2 minutes 10 s in the second period (P<0.001). The annual numbers of alert-related hospitalizations were 10.8 versus 8.1 per 100-patient-year (P=0.230), and annual numbers of alert-related visits were 9.8 and 6.1 per 100-patient-year (P=0.081), respectively. Conclusions—An optimized RM organization based on automated alerts and decisional trees enabled a focus on clinically relevant events and a decrease in the consumption of resources without compromising the quality of ICD recipients’ care.

Late diagnosis of isolated congenitally corrected transposition of the great arteries in a 92-year old woman

We report the case of a 92-year old woman with congenitally corrected transposition of the great arteries (CCTGA). The case is remarkable as the CCTGA had remained undiagnosed until the diagnosis was made when the patient was aged 70 years, and had 10 pregnancies without heart failure.

Remote monitoring of patients with implantable cardioverter-defibrillators: Can results from large clinical trials be transposed to clinical practice?

BACKGROUND Remote monitoring (RM) is increasingly used to follow up patients with implantable cardioverter-defibrillators (ICDs). Randomized control trials provide evidence for the benefit of this intervention, but data for RM in daily clinical practice with multiple-brands and unselected patients is lacking. AIMS To assess the effect of RM on patient management and clinical outcome for recipients of ICDs in daily practice. METHODS We reviewed ICD recipients followed up at our institution in 2009 with RM or with traditional hospital only (HO) follow-up. We looked at the effect of RM on the number of scheduled ambulatory follow-ups and urgent unscheduled consultations, the time between onset of asymptomatic events to clinical intervention and the clinical effectiveness of all consultations. We also evaluated the proportion of RM notifications representing clinically relevant situations. RESULTS We included 355 patients retrospectively (RM: n=144, HO: n=211, 76.9% male, 60.3±15.2 years old, 50.1% with ICDs for primary prevention and mean left ventricular ejection fraction 35.5±14.5%). Average follow-up was 13.5 months. The RM group required less scheduled ambulatory follow-up consultations (1.8 vs. 2.1/patient/year; P<0.0001) and a far lower median time between the onset of asymptomatic events and clinical intervention (7 vs. 76 days; P=0.016). Of the 784 scheduled ambulatory follow-up consultations carried out, only 152 (19.4%) resulted in therapeutic intervention or ICD reprogramming. We also found that the vast majority of RM notifications (61.9%) were of no clinical relevance. CONCLUSION RM allows early management of asymptomatic events and a reduction in scheduled ambulatory follow-up consultations in daily clinical practice, without compromising safety, endorsing RM as the new standard of care for ICD recipients.

Failed laser extraction of a fractured right ventricle defibrillator lead in a patient with persistent left superior vena cava.

Sohal et al (2) have previously reported a successful laser extraction of a 5–year-old Sprint Fidelis® ICD lead (Medtronic) through a PLSVC. The interest of our report lies in the description of the failure to extract a fractured RV-ICD lead, 6 years after the ICD implantation through a PLSVC, the placement of a new ICD RV lead, and postoperative PLSVC thrombosis. We cannot exclude that the venous occlusion might have occurred even if the defective lead was abandoned and a new lead inserted. It is however highly suspicious that the extraction caused the thrombus, because of the long sheath time manipulation and laser utilization. Venous occlusion after lead extraction is rarely described, but not properly looked for when asymptomatic (3). We used a 12-French sheath DOI: 10.5301/jva.5000475

Lack of change in myocardial function and fibrosis following a 6-day ultra-endurance exercise: A case report

a Department of Cardiovascular Medicine, Lille University Hospital, Cardiology Hospital, CHRU, 59037 Lille, France b University of Lille 2, EA4488 “Activite Physique, Muscle, Sante”, Faculty of Sports Sciences and Physical Education, 59790 Ronchin, France c Electrophysiology Service, Montreal Heart Institute, Montreal, Canada d Cardiology Department, Hopital du Bocage, University Hospital, Dijon, France, Doctrotter Medical Consulting Assistance e Radiology and Cardiovascular Imaging, Lille University Hospital, Cardiology Hospital, CHRU, 59037 Lille, France f University of Lille 2, Faculty of Medicine, 59045 Lille, France g Department of Medicine, Universite de Montreal, Montreal, Canada

0372: Outcomes of patients with unexplained syncope, bundle branch block and normal electrophysiological study

Background Little is known about predictors of high-degree atrioventricular block (AVB) in patients without evidence of advanced His-Purkinje conduction disturbances at electrophysiological study (EPS) performed for unexplained syncope associated with bundle branch block (BBB). Aims Identify electrocardiographic predictors of high-degree AVB during follow-up of these patients. Methods. In this multicenter cohort, patients were included if they had: (1) unexplained syncope, (2) bundle branch block (>120ms), (3) no HPCD at EPS, i.e. baseline HV interval Results Among the 150 studied patients (72±14 years, 62% male, mean left ventricular ejection fraction 57±8%), index electrocardiograms showed right BBB (70%; n=105), left BBB (2.7%; n=41), and nonspecific intraventricular conduction disturbance (3%; n=4). A first-degree AVB was noted in 62 patients (44.3%). During a mean follow-up of 584±88 days, high-degree AVB was documented in 25 patients (17%). The presence of a first-degree AVB on the index electrocardiogram was associated with an increased risk of subsequent high-degree AVB [72% vs. 35%; p Conclusion In patients with unexplained syncope associated with BBB, 16% of patients subsequently developed high-degree AVB despite no evidence of advanced HPCD at EPS. This was more likely to occur in patients with first-degree AVB at presentation. Conversely, this finding never occurred in patients with isolated RBBB and normal PR interval.