Philippe Coumel

Bio: Philippe Coumel is an academic researcher from University of Paris. The author has contributed to research in topics: Long QT syndrome & QT interval. The author has an hindex of 13, co-authored 18 publications receiving 17422 citations.

Genotype-Phenotype Correlation in the Long-QT Syndrome Gene-Specific Triggers for Life-Threatening Arrhythmias

Abstract: Background The congenital long-QT syndrome (LQTS) is caused by mutations on several genes, all of which encode cardiac ion channels. The progressive understanding of the electrophysiological consequences of these mutations opens unforeseen possibilities for genotype-phenotype correlation studies. Preliminary observations suggested that the conditions ("triggers") associated with cardiac events may in large part be gene specific. Methods and results We identified 670 LQTS patients of known genotype (LQT1, n=371; LQT2, n=234; LQT3, n=65) who had symptoms (syncope, cardiac arrest, sudden death) and examined whether 3 specific triggers (exercise, emotion, and sleep/rest without arousal) differed according to genotype. LQT1 patients experienced the majority of their events (62%) during exercise, and only 3% occurred during rest/sleep. These percentages were almost reversed among LQT2 and LQT3 patients, who were less likely to have events during exercise (13%) and more likely to have events during rest/sleep (29% and 39%). Lethal and nonlethal events followed the same pattern. Corrected QT interval did not differ among LQT1, LQT2, and LQT3 patients (498, 497, and 506 ms, respectively). The percent of patients who were free of recurrence with ss-blocker therapy was higher and the death rate was lower among LQT1 patients (81% and 4%, respectively) than among LQT2 (59% and 4%, respectively) and LQT3 (50% and 17%, respectively) patients. Conclusions Life-threatening arrhythmias in LQTS patients tend to occur under specific circumstances in a gene-specific manner. These data allow new insights into the mechanisms that relate the electrophysiological consequences of mutations on specific genes to clinical manifestations and offer the possibility of complementing traditional therapy with gene-specific approaches.

Notched T Waves on Holter Recordings Enhance Detection of Patients With LQT2 (HERG) Mutations

Abstract: Background—The 2 genes KCNQ1 (LQT1) and HERG (LQT2), encoding cardiac potassium channels, are the most common cause of the dominant long-QT syndrome (LQTS). In addition to QT-interval prolongation, notched T waves have been proposed as a phenotypic marker of LQTS patients. Methods and Results—The T-wave morphology of carriers of mutations in KCNQ1 (n=133) or HERG (n=57) and of 100 control subjects was analyzed from Holter ECG recordings. Averaged T-wave templates were obtained at different cycle lengths, and potential notched T waves were classified as grade 1 (G1) in case of a bulge at or below the horizontal, whatever the amplitude, and as grade 2 (G2) in case of a protuberance above the horizontal. The highest grade obtained from a template defined the notch category of the subject. T-wave morphology was normal in the majority of LQT1 and control subjects compared with LQT2 (92%, 96%, and 19%, respectively, P<0.001). G1 notches were relatively more frequent in LQT2 (18% versus 8% [LQT1] and 4% [control...

Diagnostic performance of QT interval variables from 24-h electrocardiography in the long QT syndrome

Abstract: Aims The long QT syndrome is mainly defined by QT interval prolongation (QTc >0·44s). However, data obtained in genotyped patients showed that resting QTc measurement alone may be inaccurate for ascertaining the phenotype. The aim of this study was to evaluate the diagnostic performance of QT interval rate-dependence in untreated chromosome 11-linked patients. Methods The study population consisted of 25 untreated long QT patients linked to chromosome 11 and 25 age- and gender-matched controls. QTc intervals were measured on 12-lead resting ECG recordings. From 24-h Holter recordings, the slope of the relationship between ventricular repolarization and heart rate was studied separately day and night to assess neural modulation. Mean heart rates and rate-dependences of QT and Q-maximum of T (QTm) intervals were compared between long QT patients and controls for both time periods.

Health effects of fine particulate air pollution: lines that connect

Abstract: Efforts to understand and mitigate the health effects of particulate matter (PM) air pollution have a rich and interesting history. This review focuses on six substantial lines of research that have been pursued since 1997 that have helped elucidate our understanding about the effects of PM on human health. There has been substantial progress in the evaluation of PM health effects at different time-scales of exposure and in the exploration of the shape of the concentration-response function. There has also been emerging evidence of PM-related cardiovascular health effects and growing knowledge regarding interconnected general pathophysiological pathways that link PM exposure with cardiopulmonary morbidity and mortality. Despite important gaps in scientific knowledge and continued reasons for some skepticism, a comprehensive evaluation of the research findings provides persuasive evidence that exposure to fine particulate air pollution has adverse effects on cardiopulmonary health. Although much of this research has been motivated by environmental public health policy, these results have important scientific, medical, and public health implications that are broader than debates over legally mandated air quality standards.

2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS

Abstract: The Task Force for the management of atrial fibrillation of the European Society of Cardiology (ESC) Developed with the special contribution of the European Heart Rhythm Association (EHRA) of the ESC Endorsed by the European Stroke Organisation (ESO)

Atrial Fibrillation Begets Atrial Fibrillation A Study in Awake Chronically Instrumented Goats

Abstract: Background In this study we tested the hypothesis that atrial fibrillation (AF) causes electrophysiological changes of the atrial myocardium which might explain the progressive nature of the arrhythmia. Methods and Results Twelve goats were chronically instrumented with multiple electrodes sutured to the epicardium of both atria. Two to 3 Weeks after implantation, the animals were connected to a fibrillation pacemaker which artificially maintained AF. Whereas during control episodes of AF were short lasting (6±3 seconds), artificial maintenance of AF resulted in a progressive increase in the duration of AF to become sustained (>24 hours) after 7.1±4.8 days (10 of 11 goats). During the first 24 hours of AF the median fibrillation interval shortened from 145±18 to 108±8 ms and the inducibility of AF by a single premature stimulus increased from 24% to 76%. The atrial effective refractory period (AERP) shortened from 146±19 to 95±20 ms (−35%) (S1S1, 400 ms). At high pacing rates the shortening was less (−12%...