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Background: We developed a novel electrocardiographic marker, T-wave area dispersion (TW-Ad), which measures repolarization heterogeneity by assessing interlead T-wave areas during a single cardiac cycle and tested whether it can identify patients at risk for sudden cardiac death (SCD) in the general population.Methods and Results: TW-Ad was measured from standard digital 12-lead ECG in 5618 adults (46% men; age, 50.9±12.5 years) participating in the Health 2000 Study-an epidemiological survey representative of the Finnish adult population. Independent replication was performed in 3831 participants of the KORA S4 Study (Cooperative Health Research in the Region of Augsburg; 49% men; age, 48.7±13.7 years; mean follow-up, 8.8±1.1 years). During follow-up (7.7±1.4 years), 72 SCDs occurred in the Health 2000 Survey. Lower TW-Ad was univariately associated with SCD (0.32±0.36 versus 0.60±0.19; P<0.001); it had an area under the receiver operating characteristic curve of 0.809. TW-Ad (≤0.46) conferred a hazard ratio of 10.8 (95% confidence interval, 6.8-17.4; P<0.001) for SCD; it remained independently predictive of SCD after multivariable adjustment for clinical risk markers (hazard ratio, 4.6; 95% confidence interval, 2.7-7.4; P<0.001). Replication analyses performed in the KORA S4 Study confirmed an increased risk for cardiac death (unadjusted hazard ratio, 5.5; 95% confidence interval, 3.2-9.5; P<0.001; multivariable adjusted hazard ratio, 1.9; 95% confidence interval, 1.1-3.5; P<0.05).Conclusion: Low TW-Ad, reflecting increased heterogeneity of repolarization, in standard 12-lead resting ECGs is a powerful and independent predictor of SCD in the adult general population. [ABSTRACT FROM AUTHOR]

Abstract: Introduction: Little is known about the association between electrocardiographic abnormalities and exercise‐related sudden cardiac death. Therefore, our aim was to identify possible electrocardiographic findings related to exercise‐induced sudden cardiac death. Methods and results: The FinGesture study includes 3,989 consecutive sudden cardiac deaths in northern Finland between 1998 and 2012, out of whom a total of 647 subjects had a previously recorded electrocardiography acquired from the archives of Oulu University Hospital. In 276 of these cases the death was witnessed, and the activity at the time of death was either rest or physical exercise (PE); in 40 (14%) cases sudden cardiac death was exercise‐related and in 236 (86%) cases death took place at rest. Fragmented QRS complex in at least two consecutive leads within anterior leads (V1‐V3) was more common in the exercise‐group compared to rest‐group (17 of 40, 43% vs. 51 of 236, 22%, P  =  0.005). Pathologic Q wave in anterior leads was more common in the PE group (9 of 40, 23% vs. 26 of 236, 11%; P  =  0.044). Median QRS duration was prolonged in the exercise‐group compared to the rest‐group (100 milliseconds vs. 94 milliseconds, P = 0.047). QTc interval, the prevalence of inverted T‐waves, or other electrocardiographic abnormalities did not differ significantly between the two groups. Conclusions: As a conclusion, fragmented QRS complex in the anterior leads is associated with an increased risk of sudden cardiac death during PE. [ABSTRACT FROM AUTHOR]

Background: Diabetes predisposes to sudden cardiac death (SCD). However, it is uncertain whether greater proportion of cardiac deaths are sudden among diabetes patients than other subjects. It is also unclear whether the risk of SCD is pronounced already early in the course of the disease. The relationship of impaired glucose tolerance (IGT) and SCD is scarcely documented.Methods: A general population cohort of 10594 middle-aged subjects (mean age 44 years, 52.6 % male, follow-up duration 35-41 years) was divided into diabetes patients (n = 82), subjects with IGT (n = 3806, plasma glucose ≥9.58 mmol/l in one-hour glucose tolerance test), and controls (n = 6706).Results: Diabetes patients had an increased risk of SCD after adjustment confounders (hazard ratio 2.62, 95 % confidence interval 1.46-4.70, p = 0.001) but risk for non-sudden cardiac death was similarly increased and the proportion of SCD of cardiac deaths was not increased. The SCD risk persisted after exclusion of subjects with baseline cardiac disease or non-fatal cardiac events during the follow-up. Subjects with IGT were at increased risk for SCD (univariate hazard ratio 1.51; 95 % confidence interval 1.31-1.74; p < 0.001) and also for non-sudden cardiac deaths and non-fatal cardiac events but adjustments for other risk factors attenuated these effects.Conclusions: Diabetes was associated with increased risk of SCD but also the risk of non-sudden cardiac death was similarly increased. The proportion of cardiac deaths being sudden in subjects with diabetes was not increased. The higher SCD risk in diabetes patients was independent of known cardiac disease at baseline or occurrence of non-fatal cardiac event during the follow-up. [ABSTRACT FROM AUTHOR]

Evidence of the role of body mass index (BMI) as a risk factor for sudden cardiac death (SCD) is conflicting, and how electrocardiographic (ECG) SCD risk markers perform in subjects with different BMIs is not known. In this study, a general population cohort consisting of 10,543 middle-aged subjects (mean age 44 years, 52.7% men) was divided into groups of lean (BMI <20, n = 374), normal weight (BMI 20.0 to 24.9, n = 4,334), overweight (BMI 25.0 to 29.9, n = 4,390), and obese (BMI >30, n = 1,445) subjects. Cox proportional hazards models adjusted for confounders were used to assess the risk for SCD associated with BMI and the risk for SCD associated with ECG abnormalities in subjects with different BMIs. The overweight and obese subjects were at increased risk for SCD (hazard ratios [95% CIs] were 1.33 [1.13 to 1.56], p = 0.001 and 1.79 [1.44 to 2.23], p <0.001 for overweight and obese subjects, respectively). The risk of non-SCD had a similar relation with BMI as SCD. Hazard ratios associated with ECG abnormalities were 3.03, 1.75, 1.74, and 1.34 in groups of lean, normal weight, overweight, and obese subjects, respectively, but no statistical significance was reached in the obese. ECG abnormalities improved integrated discrimination indexes and continuous net reclassification indexes statistically significantly only in the normal weight group. In conclusion, the overweight and obese are at increased risk for SCD but also for non-SCD, and ECG abnormalities are associated with increased risk of SCD also in normal weight subjects presenting with less traditional cardiovascular risk factors. [ABSTRACT FROM AUTHOR]

Background: Fragmented QRS (fQRS) on 12-lead electrocardiogram (ECG) is associated with scarred myocardium and adverse outcome. However, the data on gender differences in terms of its prevalence and prognostic value is sparse. The aim of this study was to evaluate whether gender differences in fQRS exist among subjects drawn from populations with different risk profiles., Methods: We analyzed fQRS from 12-lead ECG in 953 autopsy-confirmed victims of sudden cardiac death (SCD) (78% men; 67.0 ± 11.4 yrs), 1900 coronary artery disease (CAD) patients with angiographically confirmed stenosis of ≥50% (70% men; 66.6 ± 9.0 yrs, 43% with previous myocardial infarction [MI]), and in 10,904 adults drawn from the Finnish adult general population (52% men; 44.0 ± 8.5 yrs)., Results: Prevalence of fQRS was associated with older age, male sex and the history and severity of prior cardiac disease of subjects. Among the general population fQRS was more commonly found among men in comparison to women (20.5% vs. 14.8%, p < 0.001). The prevalence of fQRS rose gradually along with the severity of prior cardiac disease in both genders, yet remained significantly higher in the male population: subjects with suspected or known cardiac disease (25.4% vs. 15.8% p < 0.001), CAD patients without prior MI (39.9% vs. 26.4%, p < 0.001), CAD patients with prior MI (42.9% vs. 31.2%, p < 0.001), and victims of SCD (56.4% vs. 44.4%, p < 0.001)., Conclusions: The prevalence of QRS fragmentation varies in different populations. The fragmentation is clearly related to the underlying cardiac disease in both genders, however women seem to have significantly lower prevalence of fQRS in each patient population in comparison to men., (Copyright © 2020 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Early repolarization (ER) has been linked to the risk of sudden cardiac death (SCD) in the general population, although controversy remains regarding risks across various subgroups., Objective: The purpose of this study was to investigate whether age and sex influence the prognostic significance of ER., Methods: We evaluated the 12-lead electrocardiograms of 6631 Finnish general population subjects age ≥30 years (mean age 50.1 ± 13.9 years; 44.5% men) for the presence of ER (J-point elevation ≥0.1 mV in ≥2 inferior/lateral leads) and followed them for 24.4 ± 10.3 years. We analyzed the association between ER and the risk of SCD, cardiac death, and all-cause mortality in subgroups according to age (<50 or ≥50 years) and sex., Results: ER was present in 367 of the 3305 subjects age <50 years and in 426 of 3326 subjects ≥50 years. ER was not associated with any of the endpoints in the entire study population. After adjusting for clinical factors, ER was associated with SCD (hazard ratio [HR] 1.88; 95% confidence interval [CI] 1.16-3.07) in subjects <50 but not in older subjects (interaction between ER and age group, P = .048). In the younger subgroup, women with ER had a high risk of SCD (HR 4.11; 95% CI 1.41-12.03), whereas among men ER was not associated with SCD. Finally, ER was not associated with cardiac mortality or all-cause mortality in either age group., Conclusion: ER is associated with SCD in subjects younger than 50 years, particularly in women, but not in subjects 50 years and older., (Copyright © 2019 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Aim: Inferolateral early repolarization (ER) has been associated with an increased risk of sudden cardiac death (SCD). However, this association is thought to be mainly due to ischaemic SCD. The association of ER and non-ischaemic SCD has not been studied. The aim was to evaluate whether inferolateral ER is associated with non-ischaemic SCD., Methods and Results: Study population consists of 275 consecutive victims of non-ischaemic SCD with 12-lead ECG and control group of general population cohort with 10 864 subjects. Sudden cardiac deaths were verified as non-ischaemic by medicolegal autopsy. Hypertensive cardiomyopathy (HTCMP) (25%), alcohol related dilated cardiomyopathy (ACMP) (24%), obesity associated cardiomyopathy (OCMP) (23%), and idiopathic myocardial fibrosis (IMF) (15%) were the most common causes of non-ischaemic SCD. A structurally normal heart was seen in only 1.5%. The prevalence of inferolateral ER was 20.7% among patients with non-ischaemic SCD compared to 5.3% in the general population (P < 0.001). The ECG pattern was accompanied with a horizontal/descending ST segment in 95% of the cases. The prevalence of inferolateral ER was slightly higher in the HTCMP group (26%) and the ACMP group (24%) than in the IMF group (20%) and the OCMP group (13%). The history of previously diagnosed cardiac diseases was not higher among subjects with ER (55%) than those without (59%, P = 0.59)., Conclusion: The prevalence of inferolateral ER among non-ischaemic SCD victims is high. Almost all ER patterns are accompanied with the malignant horizontal/descending ST segment morphology suggesting that inferolateral ER is not only associated with an ischaemic SCD but also a non-ischaemic SCD.

The identification of patients at risk for sudden cardiac death (SCD) is still a significant challenge to clinicians and scientists. Noninvasive identification of high-risk patients has been of great interest, and several ventricular depolarization and repolarization abnormalities in the standard 12-lead electrocardiogram (ECG) have been associated with increased vulnerability to lethal ventricular arrhythmias. Several benign and pathological conditions can induce changes in repolarization detected as alteration of the ST segment or T wave. Changes in the ST segment and T waves can be early markers of an underlying cardiovascular disease, and even minor ST-T abnormalities have predicted reduced survival and increased risk of SCD in the adult population. In this review, we will discuss the current knowledge of the SCD risk with standard 12-lead ECG T wave abnormalities in the general population, and possible T wave changes in various cardiac conditions predisposing to SCD., (© 2015 Wiley Periodicals, Inc.)

Background: Early repolarization (ER) is defined as an elevation of the QRS-ST junction in at least two inferior or lateral leads of the standard 12-lead electrocardiogram (ECG). Our purpose was to create an algorithm for the automated detection and classification of ER., Methods: A total of 6,047 electrocardiograms were manually graded for ER by two experienced readers. The automated detection of ER was based on quantification of the characteristic slurring or notching in ER-positive leads. The ER detection algorithm was tested and its results were compared with manual grading, which served as the reference., Results: Readers graded 183 ECGs (3.0%) as ER positive, of which the algorithm detected 176 recordings, resulting in sensitivity of 96.2%. Of the 5,864 ER-negative recordings, the algorithm classified 5,281 as negative, resulting in 90.1% specificity. Positive and negative predictive values for the algorithm were 23.2% and 99.9%, respectively, and its accuracy was 90.2%. Inferior ER was correctly detected in 84.6% and lateral ER in 98.6% of the cases., Conclusions: As the automatic algorithm has high sensitivity, it could be used as a prescreening tool for ER; only the electrocardiograms graded positive by the algorithm would be reviewed manually. This would reduce the need for manual labor by 90%., (© 2014 Wiley Periodicals, Inc.)

Background: QRS transition zone is related to the electrical axis of the heart in the horizontal plane and is easily determined from the precordial leads of a standard 12-lead ECG. However, whether delayed QRS transition, or clockwise rotation of the heart, carries prognostic implications and predicts sudden cardiac death (SCD) is unclear., Objective: The purpose of this study was to study whether delayed transition is associated with mortality and SCD., Methods: We evaluated 12-lead ECGs of 10,815 Finnish middle-aged subjects from the general population (52% men, mean age 44 ± 8.5 years) and followed them for 30 ± 11 years. Main end-points were mortality and SCD., Results: Delayed QRS transition at lead V4 or later occurred in 1770 subjects (16.4%) and markedly delayed transition at lead V5 or later in 146 subjects (1.3%). Delayed transition zone was associated with older age, male gender, higher body mass index, hypertension, baseline cardiovascular disease, leftward shift of the frontal QRS axis, wider QRS-T angle, and ECG left ventricular hypertrophy. After adjusting for several clinical and ECG variables, delayed transition was associated with overall mortality (hazard ratio [HR] 1.15, 95% confidence interval [CI] 1.07-1.22, P < .001) and SCD (HR 1.23, 95% CI 1.03-1.47, P = .029). Markedly delayed transition at V5 or later predicted significantly SCD (HR 1.89, 95% CI 1.18-3.03, P = .008) and all-cause mortality (HR 1.30, 95% CI 1.07-1.58, P = .01). However, further adjustments for repolarization abnormalities attenuated this effect., Conclusion: Delayed QRS transition in the precordial leads of an ECG seems to be a novel ECG risk marker for SCD. In particular, markedly delayed transition was associated with significantly increased risk of SCD, independent of confounding factors., (Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Prevalence and prognostic significance of abnormal P terminal force (PTF) in the general population are not known. The aim of this study was to assess the prevalence of abnormal PTF and to compare clinical outcomes of middle-aged subjects with and without the PTF., Methods and Results: The presence of PTF was assessed in a cohort of 10 647 middle-aged subjects (mean age [SD], 44 [8] years; 47.2% female). The subjects were followed 35 to 41 years, and data on mortality and hospitalizations were obtained from national registers. Primary outcomes were all-cause mortality, cardiac mortality, and arrhythmic death. Secondary outcomes were hospitalization because of congestive heart failure, coronary heart disease, new onset atrial fibrillation, and stroke. The Cox proportional hazards model was used to assess the risk for death (all-cause), and the Fine and Gray competing risks model was used for other outcomes. The prevalence of PTF 0.04 to 0.049, 0.05 to 0.059, and ≥0.06 mm·s were 4.8%, 1.5%, and 1.2%, respectively. Subjects presenting PTF ≥0.04 mm·s were at increased risk for death, cardiac death, and congestive heart failure, and subjects presenting PTF ≥0.06 mm·s were at increased risk for atrial fibrillation. However, after adjustment for potential confounding factors, an increased risk was observed only for death (hazard ratio, 1.76; 95% confidence interval, 1.45-2.12; P<0.001) and atrial fibrillation (hazard ratio, 1.91; 95% confidence interval, 1.34-2.73; P<0.001) in subjects presenting PTF ≥0.06 mm·s., Conclusions: PTF ≥0.04 mm·s is a relatively common finding in a 12-lead ECG of middle-aged subjects. PTF ≥0.06 mm·s is associated with increased risk for atrial fibrillation and death in the general population., (© 2014 American Heart Association, Inc.)

Background: Early repolarization (ER) in the inferior/lateral leads predicts mortality, but whether ER is a specific sign of increased risk for arrhythmic events is not known., Objective: The purpose of this study was to study the association of ER and arrhythmic events and nonarrhythmic morbidity and mortality., Methods: We assessed the prognostic significance of ER in a community-based general population of 10,846 middle-aged subjects (mean age 44 ± 8 years). The end-points were sustained ventricular tachycardia or resuscitated ventricular fibrillation (VT-VF), arrhythmic death, nonarrhythmic cardiac death, new-onset atrial fibrillation (AF), hospitalization for congestive heart failure, or coronary artery disease during mean follow-up of 30 ± 11 years. ER was defined as ≥0.1-mV elevation of J point in either inferior or lateral leads., Results: After including all risk factors of cardiac mortality and morbidity in Cox regression analysis, inferior ER (prevalence 3.5%) predicted VF-VT events (n = 108 [1.0%]) with a hazard ratio (HR) of 2.2 (95% confidence interval [CI] 1.1-4.5, P = .03) but not nonarrhythmic cardiac death (n = 1235 [12.2%]), AF (n = 1659 [15.2%]), congestive heart failure (n = 1752 [16.1%]), or coronary artery disease (n = 3592 [32.9%]) (P = NS for all). Inferior ER predicted arrhythmic death in cases without other QRS complex abnormalities (multivariate HR 1.68, 95 % CI 1.10-2.58, P = .02) but not in those with ER and other coexisting abnormalities in QRS morphology (HR 1.30, 95% CI 0.86-1.96, P = .22)., Conclusion: ER in the inferior leads, especially in cases without other QRS complex abnormalities, predicts the occurrence of VT-VF but not nonarrhythmic cardiac events, suggesting that ER is a specific sign of increased vulnerability to ventricular tachyarrhythmias., (Copyright © 2014 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

We wanted to evaluate the prevalence and prognostic value of the fragmented QRS (fQRS) complex, defined as changes in QRS morphology with various RSR'-patterns in 12-lead electrocardiogram (ECG) in a middle-aged general population. We evaluated the 12-lead ECGs of 10,904 Finnish middle-aged subjects (52% men, mean age 44 ± 8.5 years) with (n = 2,543) and without (n = 8,361) an evidence of cardiac disease drawn from general population and followed them for 30 ± 11 years. Fragmentation of the QRS complex was defined as various RSR'-patterns in at least 2 consecutive leads within the same territory (inferior II, III, aVF; lateral I, aVL, V4 to V6; anterior V1 to V3). Primary end points were death from any cause, cardiac, and arrhythmic deaths. In the total population, fQRS was present in 19.7% (n = 2,147) of subjects, including 15.7% (n = 1714) in inferior leads, 0.8% (n = 84) in lateral leads, and 2.9% (n = 314) in anterior leads. Fragmentation was not associated with increased mortality in subjects without a known cardiac disease. However, fQRS observed in lateral leads in subjects with an evidence of cardiac disease was associated with an increased risk of all-cause (p = 0.001), cardiac (p = 0.001), and arrhythmic (p = 0.004) mortalities. In conclusion, fQRS reflecting minor intraventricular conduction defect is a common finding, especially in the inferior leads, but it is not a sign of increased risk of mortality in subjects without a known cardiac disease. Lateral fQRS, which is less commonly observed in the ECG, is associated with a worse outcome in patients with a known cardiac disease., (Copyright © 2014 Elsevier Inc. All rights reserved.)

Aims: Prolonged PR interval, or first degree AV block, has been traditionally regarded as a benign electrocardiographic finding in healthy individuals, until recent studies have suggested that it may be associated with increased mortality and morbidity. The aim of this study was to further elucidate clinical and prognostic importance of prolonged PR interval in a large middle-aged population with a long follow-up., Methods and Results: We evaluated 12-lead electrocardiograms of 10 785 individuals aged 30-59 years (mean age 44 years, 52% males) recorded between 1966 and 1972, and followed the subjects for 30 ± 11 years. Prolonged PR interval was defined as PR >200 ms, with further analysis performed using PR ≥220 ms. Main endpoints were all-cause mortality, cardiovascular mortality, and sudden cardiac death, and other endpoints included hospitalizations due to cardiovascular causes. During the baseline examination, prolonged PR interval >200 ms was present in 2.1% of the subjects, but PR interval normalized to ≤200 ms in 30% of these individuals during the follow-up. No increase in mortality or in hospitalizations due to coronary artery disease, heart failure, atrial fibrillation, or stroke was associated with prolonged PR interval (P = non-significant for all endpoints). These results were not changed after multivariate adjustment or in several subanalyses., Conclusion: In the middle-aged general population, prolonged PR interval normalizes in a substantial proportion of subjects during the time course, and it is not associated with an increased risk of all-cause or cardiovascular mortality.

Background: Previous population studies have found an association between electrocardiographic T-wave morphology parameters and cardiovascular mortality, but their relationship to sudden cardiac death (SCD) is not clear. To our knowledge, there are no follow-up studies assessing the association between electrocardiographic T-wave peak to T-wave end interval (TPE) and SCD. We assessed the predictive value of electrocardiographic T-wave morphology parameters and TPE for SCD in an adult general population sample., Methods and Results: A total of 4 T-wave morphology parameters (principal component analysis ratio, T-wave morphology dispersion, total cosine R-to-T, T-wave residuum) as well as TPE were measured from digital standard 12-lead ECGs in 5618 adults (46% men; mean age 50.9±12.5 years) participating in the Finnish population-based Health 2000 Study. After a mean follow-up time of 7.7±1.4 years, 72 SCDs had occurred. In univariable analyses, all T-wave morphology parameters were associated with an increased SCD risk. In multivariable Cox models, T-wave morphology dispersion and total cosine R-to-T remained as predictors of SCD, with T-wave morphology dispersion showing the highest SCD risk (hazard ratio of 1.4 [95% confidence interval 1.1-1.7, P=0.001] per 1 SD increase in the loge T-wave morphology dispersion). In contrast, TPE was not associated with SCD in univariable or multivariable analyses., Conclusions: Electrocardiographic T-wave morphology parameters describing the 3-dimensional shape of the T-wave stratify SCD risk in the general population, but we did not find an association between TPE and SCD.

Background: Electrocardiographic early repolarization (ER) pattern has been previously associated with arrhythmic mortality and with an increased risk of ventricular fibrillation. We hypothesized that there is an association between ER and sudden cardiac death (SCD) during an acute coronary event., Methods and Results: The present study included 432 consecutive victims of SCD because of acute coronary event and 532 survivors of such an event, in whom 12-lead ECGs recorded before and unrelated to the event could be evaluated. SCDs were verified by medicolegal autopsy to be because of acute coronary event. ER was defined as an elevation of the QRS-ST junction in at least 2 inferior or lateral leads, manifested as QRS notching or slurring. The prevalence of ER pattern ≥0.1 mV was more common in cases (62/432; 14.4%) than controls (42/532; 7.9%) (P=0.001). The victims of SCD were younger, were more commonly men and smokers, had lower body mass index, had elevated heart rate, had prolonged QRS complex, and had lower prevalence of history of prior cardiovascular disease than controls. After adjustments for baseline differences, the odds ratio for J waves without ST-segment elevation in the SCD group was 2.15 (95% CI, 1.20-3.85; P=0.01)., Conclusions: Higher prevalence of ER in a standard 12-lead ECG in victims of SCD than in survivors of an acute coronary event suggests that the presence of ER increases the vulnerability to fatal arrhythmia during acute myocardial ischemia and provides a plausible mechanistic link between this ECG pattern and higher arrhythmic mortality of middle-aged/elderly subjects.

Aims: Spatial QRS-T angle measured from a 12-lead electrocardiogram (ECG) has been shown to predict cardiac mortality. However, there is a paucity of studies on the prognostic significance of frontal QRS-T angle, which is more readily available from the standard 12-lead ECG. The purpose of the present study was to investigate the importance of wide frontal QRS-T angle, QRS-axis, and T-wave axis as cardiac risk predictors in general population., Methods and Results: We evaluated the 12-lead ECGs of 10 957 Finnish middle-aged subjects from the general population recorded between 1966 and 1972, and followed them for 30 ± 11 years. QRS-T angle 0 to 90°, QRS-axis -30 to 90°, and T-wave axis 0 to 90° were considered normal. The primary endpoint was death from arrhythmia, and the secondary endpoints were all-cause mortality and non-arrhythmic cardiac mortality. QRS-T angle ≥ 100° was present in 2.0% of the subjects, and it was associated with an increased risk of sudden arrhythmic death [relative risk (RR) 2.26; 95% confidence interval (CI) 1.59-3.21; P< 0.001) and all-cause mortality (RR 1.57; CI 1.34-1.84; P< 0.001), but not with non-arrhythmic cardiac mortality (RR 1.34; CI 0.93-1.92; P= 0.13). The prognostic significance of wide QRS-T angle was mainly due to abnormal T-wave axis, which predicted death from arrhythmia (RR 2.13; CI 1.63-2.79; P< 0.001), all-cause mortality (RR 1.39; 1.24-1.55; P< 0.001), and non-arrhythmic cardiac death (RR 1.87; CI 1.50-2.34; P< 0.001)., Conclusion: Frontal QRS-T angle ≥ 100° increases the risk of arrhythmic death, this being mainly the result of an altered T-wave axis.

Background: 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., Objective: 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., Methods: 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., Results: 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%)., Conclusion: 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., (Copyright © 2011 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Prolonged duration of QRS complex in a 12-lead ECG is associated with adverse prognosis in patients with cardiac disease, but its significance is not well established in the general population. In particular, there is a paucity of data on the prognostic significance of nonspecific intraventricular conduction delay in apparently healthy subjects., Methods and Results: We evaluated the 12-lead ECGs of 10 899 Finnish middle-aged subjects from the general population (52% of whom were men; mean age 44±8.5 years) between 1966 and 1972 and followed them for 30±11 years. Primary end points were all-cause mortality, cardiac mortality, and arrhythmic death. Prolonged QRS duration was defined as QRS ≥110 ms and intraventricular conduction delay as QRS ≥110 ms, without the criteria of complete or incomplete bundle-branch block. QRS duration ≥110 ms was present in 1.3% (n=147) and intraventricular conduction delay in 0.6% (n=67) of the subjects. Prolonged QRS duration predicted all-cause mortality (multivariate-adjusted relative risk [RR] 1.48; 95% confidence interval [CI] 1.22-1.81; P<0.001), cardiac mortality (RR 1.94; CI 1.44-2.63; P<0.001), and sudden arrhythmic death (RR 2.14; CI 1.38-3.33; P=0.002). Subjects with intraventricular conduction delay had increased all-cause mortality (RR 2.01; CI 1.52-2.66; P<0.001), increased cardiac mortality (RR 2.53; CI 1.64-3.90; P<0.001), and an elevated risk of arrhythmic death (RR 3.11; CI 1.74-5.54; P=0.001). Left bundle-branch block also weakly predicted arrhythmic death (P=0.04), but right bundle-branch block was not associated with increased mortality., Conclusions: Prolonged QRS duration in a standard 12-lead ECG is associated with increased mortality in a general population, with intraventricular conduction delay being most strongly associated with an increased risk of arrhythmic death.

Background: Early repolarization (ER) in inferior/lateral leads of standard ECGs increases the risk of arrhythmic death. We tested the hypothesis that variations in the ST-segment characteristics after the ER waveforms may have prognostic importance., Methods and Results: ST segments after ER were classified as horizontal/descending or rapidly ascending/upsloping on the basis of observations from 2 independent samples of young healthy athletes from Finland (n=62) and the United States (n=503), where ascending type was the dominant and common form of ER. Early repolarization was present in 27/62 (44%) of the Finnish athletes and 151/503 (30%) of the US athletes, and all but 1 of the Finnish (96%) and 91/107 (85%) of US athletes had an ascending/upsloping ST variant after ER. Subsequently, ECGs from a general population of 10 864 middle-aged subjects were analyzed to assess the prognostic modulation of ER-associated risk by ST-segment variations. Subjects with ER ≥0.1 mV and horizontal/descending ST variant (n=412) had an increased hazard ratio of arrhythmic death (relative risk 1.43; 95% confidence interval 1.05 to 1.94). When modeled for higher amplitude ER (>0.2 mV) in inferior leads and horizontal/descending ST-segment variant, the hazard ratio of arrhythmic death increased to 3.14 (95% confidence interval 1.56 to 6.30). However, in subjects with ascending ST variant, the relative risk for arrhythmic death was not increased (0.89; 95% confidence interval 0.52 to 1.55)., Conclusions: ST-segment morphology variants associated with ER separates subjects with and without an increased risk of arrhythmic death in middle-aged subjects. Rapidly ascending ST segments after the J-point, the dominant ST pattern in healthy athletes, seems to be a benign variant of ER.