Risk of sudden cardiac death associated with QRS, QTc, and JTc intervals in the general population

BACKGROUND QRS duration and corrected QT (QTc) interval have been associated with sudden cardiac death (SCD), but no data are available on the significance of repolarization component (JTc interval) of the QTc interval as an independent risk marker in the general population. OBJECTIVE In this study, we sought to quantify the risk of SCD associated with QRS, QTc, and JTc intervals. METHODS This study was conducted using data from 3 population cohorts from different eras, comprising a total of 20,058 individuals. The follow-up period was limited to 10 years and age at baseline to 30-61 years. QRS duration and QT interval (Bazett's) were measured from standard 12-lead electrocardiograms at baseline. JTc interval was defined as QTc interval - QRS duration. Cox proportional hazards models that controlled for confounding clinical factors identified at baseline were used to estimate the relative risk of SCD. RESULTS During a mean period of 9.7 years, 207 SCDs occurred (1.1 per 1000 person-years). QRS duration was associated with a significantly increased risk of SCD in each cohort (pooled hazard ratio [HR] 1.030 per 1-ms increase; 95% confidence interval [CI] 1.017-1.043). The QTc interval had borderline to significant associations with SCD and varied among cohorts (pooled HR 1.007; 95% CI 1.001-1.012). JTc interval as a continuous variable was not associated with SCD (pooled HR 1.001; 95% CI 0.996-1.007). CONCLUSION Prolonged QRS durations and QTc intervals are associated with an increased risk of SCD. However, when the QTc interval is deconstructed into QRS and JTc intervals, the repolarization component (JTc) appears to have no independent prognostic value.Peer reviewe

Risk of sudden cardiac death associated with QRS, QTc, and JTc intervals in the general population

BackgroundQRS duration and corrected QT (QTc) interval have been associated with sudden cardiac death (SCD), but no data are available on the significance of repolarization component (JTc interval) of the QTc interval as an independent risk marker in the general population.ObjectiveIn this study, we sought to quantify the risk of SCD associated with QRS, QTc, and JTc intervals.MethodsThis study was conducted using data from 3 population cohorts from different eras, comprising a total of 20,058 individuals. The follow-up period was limited to 10 years and age at baseline to 30–61 years. QRS duration and QT interval (Bazett’s) were measured from standard 12-lead electrocardiograms at baseline. JTc interval was defined as QTc interval – QRS duration. Cox proportional hazards models that controlled for confounding clinical factors identified at baseline were used to estimate the relative risk of SCD.ResultsDuring a mean period of 9.7 years, 207 SCDs occurred (1.1 per 1000 person-years). QRS duration was associated with a significantly increased risk of SCD in each cohort (pooled hazard ratio [HR] 1.030 per 1-ms increase; 95% confidence interval [CI] 1.017–1.043). The QTc interval had borderline to significant associations with SCD and varied among cohorts (pooled HR 1.007; 95% CI 1.001–1.012). JTc interval as a continuous variable was not associated with SCD (pooled HR 1.001; 95% CI 0.996–1.007).ConclusionProlonged QRS durations and QTc intervals are associated with an increased risk of SCD. However, when the QTc interval is deconstructed into QRS and JTc intervals, the repolarization component (JTc) appears to have no independent prognostic value.</p

Improving data quality, applicability and transparency of national water accounts - A case study for Finland

Highlights • A procedure for the compilation of the highly disaggregated national water accounts, and a data quality framework is described. • Sectoral data coverages and sources of error are reported and discussed. • Water accounts for self-abstracted water and mains-water are reported for 195 industries of the Finnish economy. • The accounts are primarily based on actual water supply and use rate data. • Data are reported separately for mains water, groundwater, fresh surface water, brackish water, and cooling water.This paper introduces a novel procedure for the compilation of highly disaggregated water accounts by using Finland as a case example. The procedure is based on combining the use of existing standard economic statistics and other registers and databases with a dataset on water supply and use collected in the present study. As an outcome, water supply and use accounts are presented for 195 industries in the Finnish economy in 2010. The water accounts presented are based primarily on actual water supply and use rates and distinguish between various raw water sources and uses: groundwater, fresh surface, brackish water self-abstracted for own use, and mains-water supply and use. Separate accounts for cooling water are presented. The paper covers flow accounts from the environment to the economy and within the economy excluding all return flows. Data coverage issues and potential sources of error are reported in detail and discussed together with the applicability of the procedure in other countries. Implications for the System of Economic-Environmental Accounting for Water (SEEA-Water) framework are assessed

ECG left ventricular hypertrophy as a risk predictor of sudden cardiac death

Background: Electrocardiographic (ECG) left ventricular hypertrophy (LVH) is an established risk factor for cardiovascular events. However, limited data is available on the prognostic values of different ECG LVH criteria specifically to sudden cardiac death (SCD). Our goal was to assess relationships of different ECG LVH criteria to SCD. Methods: Three traditional and clinically useful (Sokolow-Lyon, Cornell, RaVL) and a recently proposed (Peguero-Lo Presti) ECG LVH voltage criteria were measured in 5730 subjects in the Health 2000 Survey, a national general population cohort study. Relationships between LVH criteria, aswell as their selected composites, to SCD were analyzed with Cox regression models. In addition, population-attributable fractions for LVH criteria were calculated. Results: After a mean follow-up of 12.5 +/- 2.2 years, 134 SCDs had occurred. When used as continuous variables, all LVH criteria except for RaVL were associated with SCD in multivariable analyses. When single LVH criteria were used as dichotomous variables, only Cornell was significant after adjustments. The dichotomous composite of Sokolow-Lyon and Cornell was also significant after adjustments (hazard ratio for SCD 1.82, 95% confidence interval 1.20-2.70, P = 0.006) and was the only LVH measure that showed statistically significant population attributable fraction (11.0%, 95% confidence interval 1.9-19.2%, P=0.019). Conclusions: Sokolow-Lyon, Cornell, and Peguero-Lo Presti ECG, but not RaVL voltage, are associated with SCD risk as continuous ECG voltage LVH variables. When SCD risk assessment/adjustment is performed using a dichotomous ECG LVH measure, composite of Sokolow-Lyon and Cornell voltages is the preferred option. (c) 2018 The Authors. Published by Elsevier B.V.Peer reviewe

Causes of nonischemic sudden cardiac death in the current era

Previous data have shown that various nonischemic cardiac diseases account for about 20% of sudden cardiac deaths (SCDs) and that dilated and hypertrophic cardiomyopathy (CM) are major causes of nonischemic SCD. The purpose of this study was to define the prevalence and causes of SCD due to nonischemic CM in the current era given the substantial change in the diagnosis and treatment of cardiac diseases and in lifestyle patterns. A total of 2661 consecutive victims of SCD from among a population of approximately 470,000 inhabitants in the Province of Oulu, Northern Finland, were included in the study. The causes of deaths were determined from the uniformly required autopsies of SCD victims in Finland, plus available medical records and standardized questionnaires. Nonischemic cause of SCD was found in 579 victims (21.8% of all the SCDs). Mean age (± SD) was 55 (±12) years; 78% were males. After subgrouping the nonischemic SCDs into various categories, SCDs associated most closely with obesity (23.7%), followed by alcoholic CM (19.0%), hypertensive CM (15.5%), and fibrotic CM (13.6%). Fibrotic CM was the most common association with SCD in subjects younger than 40 years (28.3%), whereas alcoholic CM was the most common cause of death in subjects between 40 and 59 years of age (25.8%). CM related to obesity, fibrotic CM, and alcoholic CM are commonly associated with nonischemic SCD in the current era. The association of SCD with fibrotic CM is notably frequent among victims younger than 40 years

Electrocardiographic risk markers for heart failure in women versus men

Abstract Heart failure (HF) is one of the leading causes of hospitalization in the Western world. Women have a lower HF hospitalization rate and mortality compared with men. The role of electrocardiography as a risk marker of future HF in women is not well known. We studied association of electrocardiographic (ECG) risk factors for HF hospitalization in women from a large middle-aged general population with a long-term follow-up and compared the risk profile to men. Standard 12-lead ECG markers were analyzed from 10,864 subjects (49% women), and their predictive value for HF hospitalization was analyzed. During the follow-up (30 ± 11 years), a total of 1,743 subjects had HF hospitalization; of these, 861 were women (49%). Several baseline characteristics, such as age, body mass index, blood pressure, and history of previous cardiac disease predicted the occurrence of HF both in women and men (p &lt;0.001 for all). After adjusting for baseline variables, ECG sign of left ventricular hypertrophy (LVH) (p &lt;0.001), and atrial fibrillation (p &lt;0.001) were the only baseline ECG variables that predicted future HF in women. In men, HF was predicted by fast heart rate (p = 0.008), T wave inversions (p &lt;0.001), abnormal Q-waves (p = 0.002), and atrial fibrillation (p &lt;0.001). Statistically significant gender interactions in prediction of HF were observed in ECG sign of LVH, inferolateral T wave inversions, and heart rate. In conclusion, ECG sign of LVH predicts future HF in middle-aged women, and T wave inversions and elevated heart rate are associated with HF hospitalization in men