The Experts below are selected from a list of 45453 Experts worldwide ranked by ideXlab platform
Richard J Cohen - One of the best experts on this subject based on the ideXlab platform.
-
predicting Sudden Cardiac Death from t wave alternans of the surface electrocardiogram promise and pitfalls
Journal of Cardiovascular Electrophysiology, 1996Co-Authors: S David M D Rosenbaum, Paul Albrecht, Richard J CohenAbstract:T Wave Alternans and Sudden Cardiac Death. Sudden Cardiac Death remains a preeminent public health problem. Despite advances in preventative treatment for patients known to be at risk, to date we have been able to identify, and thus treat, only a small minority of these patients. Therefore, there is a major need to develop noninvasive diagnostic technologies to identify patients at risk. Recent studies have demonstrated that measurement of microvolt-level T wave alternans is a promising technique for the accurate identification of patients at risk for ventricular arrhythmias and Sudden Cardiac Death. In this article, we review the clinical data establishing the relationship between microvolt T wave alternans and susceptibility to ventricular arrhythmias. We also review the methods and technology that have been developed to measure microvolt levels of T wave alternans noninvasively in broad populations of ambulatory patients. In particular, we examine techniques that permit the accurate measurement of T wave alternans during exercise stress testing.
-
Predicting Sudden Cardiac Death from T wave alternans of the surface electrocardiogram: promise and pitfalls.
Journal of cardiovascular electrophysiology, 1996Co-Authors: David S Rosenbaum, Paul Albrecht, Richard J CohenAbstract:Sudden Cardiac Death remains a preeminent public health problem. Despite advances in preventative treatment for patients known to be at risk, to date we have been able to identify, and thus treat, only a small minority of these patients. Therefore, there is a major need to develop noninvasive diagnostic technologies to identify patients at risk. Recent studies have demonstrated that measurement of microvolt-level T wave alternans is a promising technique for the accurate identification of patients at risk for ventricular arrhythmias and Sudden Cardiac Death. In this article, we review the clinical data establishing the relationship between microvolt T wave alternans and susceptibility to ventricular arrhythmias. We also review the methods and technology that have been developed to measure microvolt levels of T wave alternans noninvasively in broad populations of ambulatory patients. In particular, we examine techniques that permit the accurate measurement of T wave alternans during exercise stress testing.
Elio Riboli - One of the best experts on this subject based on the ideXlab platform.
-
tobacco smoking and the risk of Sudden Cardiac Death a systematic review and meta analysis of prospective studies
European Journal of Epidemiology, 2018Co-Authors: Dagfinn Aune, Teresa Norat, Sabrina Schlesinger, Elio RiboliAbstract:Smoking is an established risk factor for cardiovascular disease including coronary heart disease and stroke, however, data regarding smoking and Sudden Cardiac Death have not been summarized in a meta-analysis previously. We therefore conducted a systematic review and meta-analysis to clarify this association. We searched the PubMed and Embase databases for studies of smoking and Sudden Cardiac Death up to July 20th 2017. Prospective studies were included if they reported adjusted relative risk (RR) estimates and 95% confidence intervals (CIs) for smoking and Sudden Cardiac Death. Summary RRs were estimated by use of a random effects model. Twelve prospective studies were included. The summary RR was 3.06 (95% CI 2.46–3.82, I2 = 41%, pheterogeneity = 0.12, n = 7) for current smokers and 1.38 (95% CI 1.20–1.60, I2 = 0%, pheterogeneity = 0.55, n = 7) for former smokers compared to never smokers. For four studies using non-current (never + former) smokers as the reference category the summary RR among current smokers was 2.08 (95% CI 1.70–2.53, I2 = 18%, pheterogeneity = 0.30). The results persisted in most of the subgroup analyses. There was no evidence of publication bias. These results confirm that smoking increases the risk of Sudden Cardiac Death. Any further studies should investigate in more detail the effects of duration of smoking, number of cigarettes per day, pack-years, and time since quitting smoking and Sudden Cardiac Death.
-
body mass index abdominal fatness and the risk of Sudden Cardiac Death a systematic review and dose response meta analysis of prospective studies
European Journal of Epidemiology, 2018Co-Authors: Dagfinn Aune, Teresa Norat, Sabrina Schlesinger, Elio RiboliAbstract:Although overweight and obesity are established risk factors for some types of heart disease including ischemic heart disease, heart failure and atrial fibrillation, less is known about the association between adiposity and Sudden Cardiac Death. We conducted a systematic review and meta-analysis of prospective studies to clarify the association between adiposity and risk of Sudden Cardiac Death. PubMed and Embase databases were searched up to July 20th 2017. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random effects models. The summary RR was 1.16 (95% CI 1.05–1.28, I2 = 68%, n = 14) per 5 unit increment in BMI, and 1.82 (95% CI 1.61–2.07, I2 = 0%, n = 3) per 0.1 unit increase in waist-to-hip ratio, and 1.03 (95% CI 0.93–1.15, I2 = 0%, n = 2) per 10 cm increase in waist circumference. The heterogeneity in the analysis of BMI and Sudden Cardiac Death persisted across most subgroup analyses. The association was stronger among studies with longer follow-up compared to short follow-up and was observed in the European and American studies, but not in the Asian studies. There was a J-shaped association between BMI and Sudden Cardiac Death and the lowest risk was observed in the normal weight range, however, the increased risk with a low BMI was attenuated among studies with a longer duration of follow-up. This meta-analysis suggest an increased risk of Sudden Cardiac Death with increasing BMI and waist-to-hip ratio, however, further studies with stratification for smoking status are needed of waist circumference, weight changes and adiposity at younger ages.
Dagfinn Aune - One of the best experts on this subject based on the ideXlab platform.
-
tobacco smoking and the risk of Sudden Cardiac Death a systematic review and meta analysis of prospective studies
European Journal of Epidemiology, 2018Co-Authors: Dagfinn Aune, Teresa Norat, Sabrina Schlesinger, Elio RiboliAbstract:Smoking is an established risk factor for cardiovascular disease including coronary heart disease and stroke, however, data regarding smoking and Sudden Cardiac Death have not been summarized in a meta-analysis previously. We therefore conducted a systematic review and meta-analysis to clarify this association. We searched the PubMed and Embase databases for studies of smoking and Sudden Cardiac Death up to July 20th 2017. Prospective studies were included if they reported adjusted relative risk (RR) estimates and 95% confidence intervals (CIs) for smoking and Sudden Cardiac Death. Summary RRs were estimated by use of a random effects model. Twelve prospective studies were included. The summary RR was 3.06 (95% CI 2.46–3.82, I2 = 41%, pheterogeneity = 0.12, n = 7) for current smokers and 1.38 (95% CI 1.20–1.60, I2 = 0%, pheterogeneity = 0.55, n = 7) for former smokers compared to never smokers. For four studies using non-current (never + former) smokers as the reference category the summary RR among current smokers was 2.08 (95% CI 1.70–2.53, I2 = 18%, pheterogeneity = 0.30). The results persisted in most of the subgroup analyses. There was no evidence of publication bias. These results confirm that smoking increases the risk of Sudden Cardiac Death. Any further studies should investigate in more detail the effects of duration of smoking, number of cigarettes per day, pack-years, and time since quitting smoking and Sudden Cardiac Death.
-
body mass index abdominal fatness and the risk of Sudden Cardiac Death a systematic review and dose response meta analysis of prospective studies
European Journal of Epidemiology, 2018Co-Authors: Dagfinn Aune, Teresa Norat, Sabrina Schlesinger, Elio RiboliAbstract:Although overweight and obesity are established risk factors for some types of heart disease including ischemic heart disease, heart failure and atrial fibrillation, less is known about the association between adiposity and Sudden Cardiac Death. We conducted a systematic review and meta-analysis of prospective studies to clarify the association between adiposity and risk of Sudden Cardiac Death. PubMed and Embase databases were searched up to July 20th 2017. Summary relative risks (RRs) and 95% confidence intervals (CIs) were calculated using random effects models. The summary RR was 1.16 (95% CI 1.05–1.28, I2 = 68%, n = 14) per 5 unit increment in BMI, and 1.82 (95% CI 1.61–2.07, I2 = 0%, n = 3) per 0.1 unit increase in waist-to-hip ratio, and 1.03 (95% CI 0.93–1.15, I2 = 0%, n = 2) per 10 cm increase in waist circumference. The heterogeneity in the analysis of BMI and Sudden Cardiac Death persisted across most subgroup analyses. The association was stronger among studies with longer follow-up compared to short follow-up and was observed in the European and American studies, but not in the Asian studies. There was a J-shaped association between BMI and Sudden Cardiac Death and the lowest risk was observed in the normal weight range, however, the increased risk with a low BMI was attenuated among studies with a longer duration of follow-up. This meta-analysis suggest an increased risk of Sudden Cardiac Death with increasing BMI and waist-to-hip ratio, however, further studies with stratification for smoking status are needed of waist circumference, weight changes and adiposity at younger ages.
Timo H Makikallio - One of the best experts on this subject based on the ideXlab platform.
-
asymptomatic st segment depression during exercise testing and the risk of Sudden Cardiac Death in middle aged men a population based follow up study
European Heart Journal, 2009Co-Authors: Jari A Laukkanen, Timo H Makikallio, Rainer Rauramaa, Sudhir KurlAbstract:Aims Silent electrocardiographic ST change predicts future coronary events in patients with coronary heart disease (CHD), but the prognostic significance of asymptomatic ST-segment depression with respect to Sudden Cardiac Death in subjects without apparent CHD is not well known. Methods and results We investigated the association between silent ST-segment depression during and after maximal symptom-limited exercise test and the risk of Sudden Cardiac Death in a population-based sample of 1769 men without evident CHD. A total of 72 Sudden Cardiac Death occurred during the median follow-up of 18 years. The risk of Sudden Cardiac Death was increased among men with asymptomatic ST-segment depression during exercise [hazard ratio (HR) 2.1, 95% confidence interval (CI) 1.2–3.9] as well as among those with asymptomatic ST-segment depression during recovery period (HR 3.2, 95% CI 1.7–6.0). Asymptomatic ST-depression during exercise testing was a stronger predictor for the risk of Sudden Cardiac Death especially among smokers as well as in hypercholesterolaemic and hypertensive men than in men without these risk factors. Conclusion Asymptomatic ST-segment depression was a very strong predictor of Sudden Cardiac Death in men with any conventional risk factor but no previously diagnosed CHD, emphasizing the value of exercise testing to identify asymptomatic high-risk men who could benefit from preventive measures.
-
prediction of Sudden Cardiac Death by fractal analysis of heart rate variability in elderly subjects
Journal of the American College of Cardiology, 2001Co-Authors: Timo H Makikallio, Heikki V Huikuri, Anne Makikallio, L Sourander, Raul D Mitrani, Agustin Castellanos, Robert J MyerburgAbstract:OBJECTIVES The aim of this study was to test the hypothesis that abnormal scaling characteristics of heart rate (HR) predict Sudden Cardiac Death in a random population of elderly subjects. BACKGROUND An abnormality in the short-term fractal scaling properties of HR has been observed to be related to a risk of life-threatening arrhythmias among patients with advanced heart diseases. The predictive power of altered short-term scaling properties of HR in general populations is unknown. METHODS A random sample of 325 subjects, age 65 years or older, who had a comprehensive risk profiling from clinical evaluation, laboratory tests and 24-h Holter recordings were followed up for 10 years. Heart rate dynamics, including conventional and fractal scaling measures of HR variability, were analyzed. RESULTS At 10 years of follow-up, 164 subjects had died. Seventy-one subjects had died of a Cardiac cause, and 29 Deaths were defined as Sudden Cardiac Deaths. By univariate analysis, a reduced short-term fractal scaling exponent predicted the occurrence of Cardiac Death (relative risk [RR] 2.5, 95% confidence interval [CI], 1.9 to 3.2, p < 0.001) and provided even stronger prediction of Sudden Cardiac Death (RR 4.1, 95% CI, 2.5 to 6.6, p < 0.001). After adjusting for other predictive variables in a multivariate analysis, reduced exponent value remained as an independent predictor of Sudden Cardiac Death (RR 4.3, 95% CI, 2.0 to 9.2, p < 0.001). CONCLUSIONS Altered short-term fractal scaling properties of HR indicate an increased risk for Cardiac mortality, particularly Sudden Cardiac Death, in the random population of elderly subjects.
David S Rosenbaum - One of the best experts on this subject based on the ideXlab platform.
-
repolarization alternans implications for the mechanism and prevention of Sudden Cardiac Death
Cardiovascular Research, 2003Co-Authors: Mariah L Walker, David S RosenbaumAbstract:For nearly 100 years, beat to beat alternation of T wave amplitude, termed T wave alternans (TWA), has been closely linked to electrical instability in the heart. TWA is now established among the strongest markers of susceptibility to Sudden Cardiac Death. Since computer technology allows for detection of very subtle yet clinically significant TWA during standard exercise testing, TWA has been used increasingly as a noninvasive clinical tool for identifying and treating patients at risk for Sudden Cardiac Death. The observation of TWA hastening ventricular tachyarrhythmias in an extraordinary variety of clinical and experimental conditions suggest potential universality of TWA in the pathophysiological mechanism of Sudden Death. High resolution optical mapping studies have shown that TWA arises from alternans of repolarization at the level of the ventricular myocyte. Cellular alternans is likely due to the actions of one or more ionic currents and is closely related to, if not directly dependent on, the kinetics of intracellular calcium cycling. Impairment in calcium cycling at the cellular and sub-cellular levels has been implicated in the mechanism of cellulcar alternans. Importantly, spatially discordant alternans between cells is most likely a consequence of heterogeneities of electrophysiological properties between cells which span the ventricular wall, serving to amplify spatial heterogeneities of repolarization, and forming a substrate for reentrant excitation. Through this mechanism, TWA is linked directly and mechanistically to the pathogenesis of arrhythmias. Although available data would suggest that TWA is certainly closely related to a mechanism of arrhythmogenesis, and is a strong marker of clinical risk, the precise sequence of events which triggers Sudden Cardiac Death, and the potential role of TWA in this process remains elusive.
-
Predicting Sudden Cardiac Death from T wave alternans of the surface electrocardiogram: promise and pitfalls.
Journal of cardiovascular electrophysiology, 1996Co-Authors: David S Rosenbaum, Paul Albrecht, Richard J CohenAbstract:Sudden Cardiac Death remains a preeminent public health problem. Despite advances in preventative treatment for patients known to be at risk, to date we have been able to identify, and thus treat, only a small minority of these patients. Therefore, there is a major need to develop noninvasive diagnostic technologies to identify patients at risk. Recent studies have demonstrated that measurement of microvolt-level T wave alternans is a promising technique for the accurate identification of patients at risk for ventricular arrhythmias and Sudden Cardiac Death. In this article, we review the clinical data establishing the relationship between microvolt T wave alternans and susceptibility to ventricular arrhythmias. We also review the methods and technology that have been developed to measure microvolt levels of T wave alternans noninvasively in broad populations of ambulatory patients. In particular, we examine techniques that permit the accurate measurement of T wave alternans during exercise stress testing.
