T-wave inversion, QRS duration, and QRS/T angle as electrocardiographic predictors of the risk for sudden cardiac death

Long COVID in Uganda: Electrographic findings among patients at risk

Background

COVID-19 has a significant cardiovascular involvement. Electrocardiographic (ECG) abnormalities among people at a risk of Long COVID in Uganda was investigated.

Methods

A cross-sectional study was conducted from February to June 2022 at the post COVID - 19 clinic in Mulago National Specialized Hospital, Kampala. A standard resting ECG was performed on individuals at least 2 months following acute COVID-19, with a negative SARS-CoV-2 reverse-transcription polymerase chain reaction. Sociodemographic and clinical characteristics as well as vital signs were recorded for all study participants.

Results

Of the 244 study participants, 117 (47.9%) were female. The median age of all the participants was 33.0 (interquartile range: 26.0 - 43.5) years. Twenty-five (10.2%) participants had a history of smoking while 117 (48%) had a history of alcohol intake. In total, 46 (18.9%) had abnormal ECG findings (95% Confidence Interval (CI): 14.39 - 24.29) and non-specific T-wave inversion (n = 16, 34%) was the most frequent ECG abnormality. The proportion of participants with ECG abnormalities was 48% lower among females (adjusted prevalence ratio (aPR): 0.52, 95% CI: 0.28 - 0.96, p value < 0.05) and 2-fold greater for those with a history of smoking (aPR: 2.03, 95% CI:1.096 - 3.776, p value < 0.05).

Conclusion

One in five Ugandans who were checked at the clinic at a risk of Long COVID showed ECG abnormalities. ECG screening is suggested to be integrated into the follow-up care of those at a risk of Long COVID.

The Association of QRS Duration with Risk of Adverse Outcomes in Sex- and Race- Based Subgroups: The Dallas Heart Study

Introduction

We explored sex and race differences in the prognostic implications of QRS prolongation among healthy adults.

Methods

Participants from the Dallas Heart Study (DHS) free of cardiovascular (CV) disease who underwent ECG testing and cMRI evaluation were included. Multivariable linear regression was used to examine the cross-sectional association of QRS duration with left ventricular (LV) mass, LV ejection fraction (LVEF), and LV end diastolic volume (LVEDV). Association of QRS duration with risk of MACE was evaluated using Cox models. Interaction testing was performed between QRS duration and sex/race respectively for each outcome of interest. QRS duration was log transformed.

Results

The study included 2,785 participants. Longer QRS duration was associated with higher LV mass, lower LVEF, and higher LVEDV, independent of CV risk factors ([β: 0.21, P<0.001], [β: - 0.13, P<0.001], [β: 0.22, P<0.001] respectively). Men with longer QRS duration were more likely to have higher LV mass and higher LVEDV compared to women (P-int=0.012, P-int=0.01, respectively). Black participants with longer QRS duration were more likely to have higher LV mass as compared to White participants (P-int<0.001). In Cox analysis, QRS prolongation was associated with higher risk of MACE in women (HR = 6.66 [95% CI: 2.32, 19.1]) but not men. This association was attenuated after adjustment for CV risk factors, with a trend toward significance (HR = 2.45 [95% CI: 0.94, 6.39]). Longer QRS duration was not associated with risk of MACE in Black or White participants in the adjusted models. No interaction between sex/race and QRS duration for risk of MACE was observed.

Discussion

In healthy adults, QRS duration is differentially associated with abnormalities in LV structure and function. These findings inform the use of QRS duration in identifying subgroups at risk for CV disease, and caution against using QRS duration cut offs uniformly for clinical decision making.

What is known?

QRS prolongation in healthy adults is associated with higher risk of death, cardiovascular disease, and left ventricular hypertrophy.

What the study adds?

QRS prolongation may reflect a higher degree of underlying LV hypertrophy in Blacks compared to Whites. Longer QRS interval may reflect higher risk of adverse cardiac events, driven by prevalent cardiovascular risk factors.

Graphic Abstract

Risk of underlying left ventricular hypertrophy in demographic groups based on QRS prolongation.

Longitudinal association of ECG abnormalities with major adverse cardiac events in people with type 2 diabetes: The Hoorn Diabetes Care System cohort

AIMS

To investigate the association of (changes in) ECG abnormalities with incident major adverse cardiac events (MACE) in people with type 2 diabetes (T2D) without pre-existing cardiovascular disease (CVD).

METHODS

A prospective longitudinal study of 11,993 people with T2D without known CVD from the Hoorn Diabetes Care System cohort. Annually repeated measurements (1998-2018), included cardiovascular risk factors, over 70,000 ECGs, and self-reported cardiovascular events. ECG abnormalities were classified according to the Minnesota Classification as prolonged PR duration, prolonged QRS duration, left QRS-axis, QS pattern, ST-segment/T-wave abnormalities, or tall R-wave. The association of ECG abnormalities with MACEs was assessed using time-dependent Cox-regression models, adjusted for time-varying cardiovascular risk factors and medication use (Hazzard Ratios with 95%CIs).

RESULTS

During a median follow-up of 6.6 (IQR, 3.1-10.7) years, 5445 (45.4%) of the participants had an ECG abnormality (prevalent or incident) at any of the median 6 (IQR, 3-10) annual ECG recordings, and 905 people (7.5%) had a MACE (529 CHD, 250 HF, 126 SCA). After adjustment, most ECG abnormalities were associated with HF: prolonged QRS duration (HR, 4.01 (95%CI, 2.67-6.03)), QS pattern (2.68 (0.85-8.49)), ST-segment/T-wave abnormalities (4.26 (2.67-6.80)), and tall R-wave (2.23 (1.33-3.76)). Only QS pattern (2.69 (1.20-6.03)), and ST-segment/T-wave abnormalities (2.11 (1.48-3.02)) were associated with CHD. These associations were robust across age, sex, hypertension, or estimated CVD risk subgroups.

CONCLUSION

In people with T2D without pre-existing cardiovascular disease, ECG abnormalities related to decelerated conduction, ischemia and hypertrophy are predominantly early signs of emerging HF, while only abnormalities related to ischemic disorders are signs of CHD.

Predictive value of electrocardiographic markers in children with dilated cardiomyopathy

Dilated cardiomyopathy (DCM) refers to a heterogeneous group of cardiomyopathies characterized by ventricular dilatation and myocardial systolic dysfunction, which can lead to serious consequences such as malign arrhythmia, sudden death, heart failure, and thromboembolism. With its economical, non-invasive, simple and reproducible advantages, electrocardiogram (ECG) has become an important indicator for assessing the prognosis of cardiovascular diseases. In recent years, more and more studies of electrocardiography on DCM have been carried out, but there is still a lack of a comprehensive summary of its prognostic value. This article reviews the prognostic value of electrocardiographic markers in children with DCM.

Incremental changes in QRS duration as predictor for cardiovascular disease: a 21-year follow-up of a randomly selected general population

The QRS complex has been shown to be a prognostic marker in coronary artery disease. However, the changes in QRS duration over time, and its predictive value for cardiovascular disease in the general population is poorly studied. So we aimed to explore if increased QRS duration from the age of 50–60 is associated with increased risk of major cardiovascular events during a further follow-up to age 71. A random population sample of 798 men born in 1943 were examined in 1993 at 50 years of age, and re-examined in 2003 at age 60 and 2014 at age 71. Participants who developed cardiovascular disease before the re-examination in 2003 (n = 86) or missing value of QRS duration in 2003 (n = 127) were excluded. ΔQRS was defined as increase in QRS duration from age 50 to 60. Participants were divided into three groups: group 1: ΔQRS < 4 ms, group 2: 4 ms ≤ ΔQRS < 8 ms, group 3: ΔQRS ≥ 8 ms. Endpoints were major cardiovascular events. And we found compared with men in group 1 (ΔQRS < 4 ms), men with ΔQRS ≥ 8 ms had a 56% increased risk of MACE during follow-up to 71 years of age after adjusted for BMI, systolic blood pressure, smoking, hyperlipidemia, diabetes and heart rate in a multivariable Cox regression analysis (HR 1.56, 95% CI:1.07–2.27, P = 0.022). In conclusion, in this longitudinal follow-up over a decade QRS duration increased in almost two out of three men between age 50 and 60 and the increased QRS duration in middle age is an independent predictor of major cardiovascular events.

The effect of Systolic and diastolic blood pressure on Tp-e interval in patients divided according to World Health Organization classification for body mass index

Background: Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio are electrocardiographic markers and indices of ventricular arrhythmogenic events. We aimed to investigate ventricular repolarization in normal weight, overweight, obese and morbidly obese individuals by using ECG parameters including the above markers.Methods: A total of 310 obese patients with various cardiac complaints, who were admitted to our outpatient clinic between May 2020 and January 2021, were prospectively included in the study. Using the World Health Organization (WHO) body mass index (BMI) classification, patients were divided into four groups: normal weight (18.5-24.9 kg/m², n = 48), overweight (25-29.9 kg/m², n = 98), obese (30-39.9 kg/m², n = 119), and morbidly obese (>40 kg/m², n = 45).Results: The morbidly obese and normal groups were younger in age than the other two groups. The Tp-e interval values for Groups I-IV were 72.1 ± 6.9, 73.1 ± 6.2, 75.7 ± 7.3 and 81.1 ± 6.9, respectively, and significantly different (P < .001). We found that age, BMI, systolic blood pressure (BP) and diastolic BP were independent predictors of a prolonged Tp-e interval.Conclusions: The principal finding of our study was the gradual increase in Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio starting from the overweight stage and these parameters gradually increase in obese and morbidly obese patients. Additionally, systolic and diastolic blood pressure predicted Tp-e interval, Tp-e/QT ratio and Tp-e/QTc ratio.

Fragmented QRS on surface electrocardiography as a predictor of cardiac mortality in patients with SARS-CoV-2 infection

Aims

Although severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection is mainly a respiratory system disease, recent studies reported that cardiac injury is associated with poor outcomes in this population. There are few studies which assessed standard electrocardiogram (ECG) as a prognostic tool during the course of SARS-CoV-2 infection. The aim of this study is to identify the relationship between of ECG parameters and prognosis of patients infected with SARS-CoV-2.

Method and results

A total of 114 consecutive patients with a confirmed diagnosis of SARS-CoV-2 infection between March 2020 and May 2020 were included in the study. Standard 12‑lead surface ECG was reviewed for presence of fragmented QRS (fQRS), abnormal Q wave, T wave inversion, and duration of QRS. fQRS was observed in 36.8% (n = 42) of the patients who had SARS-CoV-2. Patient groups with and without fQRS did not differ in terms of age, gender, the presence of comorbid diseases and medical treatment. Hospitalization duration, intensive care unit(ICU) requirement, all-cause mortality, and cardiac mortality were found to be higher in patients with fQRS (all p values <0.05). There was a positive correlation between QRS duration and duration of hospital stay (p < 0.001, r = 0.421). QRS duration was also found to be associated with intensive care need, all-cause mortality, and cardiac mortality.

Conclusion

Our data shows that QRS duration and the presence of fQRS on standard ECG can help to identify patients with worse clinical outcome admitted for SARS-CoV-2 infection.

A genome-wide association and polygenic risk score study on abnormal electrocardiogram in a Chinese population

Electrocardiography is a common and widely-performed medical examination based on the measurement and evaluation of electrocardiogram (ECG) to assess the up-to-date cardiac rhythms and thus suggest the health conditions of cardiovascular system and on a larger level the individual’s wellness. Abnormal ECG assessment from the detection of abnormal heart rhythms may have clinical implications including blood clots in formation, ongoing heart attack, coronary artery blockage, etc. Past genetic-phenotypic research focused primarily on the physical parameters of ECG but not the medical evaluation. To unbiasedly uncover the underlying links of genetic variants with normal vs. abnormal ECG assessment, a genome-wide association study (GWAS) is carried out in a 1006-participant cohort of Chinese population effectively genotyped for 243487 single nucleotide polymorphisms (SNPs). Both age and sex are influential factors, and six novel SNPs are identified for potential association with abnormal ECG. With the selected SNPs, a polygenic risk score (PRS) differentiates the case–control subgroups, and correlates well with increased risk of abnormal ECG. The findings are reproduced in an independent validation cohort. The derived PRS may function as a potential biomarker for prospectively screening the high-risk subgroup of heart issues in the Chinese population.

Electrocardiographic Risk Markers of Cardiac Death: Gender Differences in the General Population

Background

Cardiac death is one of the leading causes of death and sudden cardiac death (SCD) is estimated to cause approximately 50% of cardiac deaths. Men have a higher cardiac mortality than women. Consequently, the mechanisms and risk markers of cardiac mortality are not as well defined in women as they are in men.

Aim

The aim of the study was to assess the prognostic value and possible gender differences of SCD risk markers of standard 12-lead electrocardiogram in three large general population samples.

Methods

The standard 12-lead electrocardiographic (ECG) markers were analyzed from three different Finnish general population samples including total of 20,310 subjects (49.9% women, mean age 44.8 ± 8.7 years). The primary endpoint was cardiac death, and SCD and all-cause mortality were secondary endpoints. The interaction effect between women and men was assessed for each ECG variable.

Results

During the follow-up (7.7 ± 1.2 years), a total of 883 deaths occurred (24.5% women, p < 0.001). There were 296 cardiac deaths (13.9% women, p < 0.001) and 149 SCDs (14.8% women, p < 0.001). Among those who had died due to cardiac cause, women had more often a normal electrocardiogram compared to men (39.0 vs. 27.5%, p = 0.132). After adjustments with common cardiovascular risk factors and the population sample, the following ECG variables predicted the primary endpoint in men: left ventricular hypertrophy (LVH) with strain pattern (p < 0.001), QRS duration > 110 ms (p < 0.001), inferior or lateral T-wave inversion (p < 0.001) and inferolateral early repolarization (p = 0.033). In women none of the variables remained significant predictors of cardiac death in multivariable analysis, but LVH, QTc ≥ 490 ms and T-wave inversions predicted SCD (p < 0.047 and 0.033, respectively). In the interaction analysis, LVH (HR: 2.4; 95% CI: 1.2–4.9; p = 0.014) was stronger predictor of primary endpoint in women than in men.

Conclusion

Several standard ECG variables provide independent information on the risk of cardiac mortality in men but not in women. LVH and T-wave inversions predict SCD also in women.

Clinical Implications of Fragmented QRS Complex as an Outcome Predictor in Children with Idiopathic Dilated Cardiomyopathy

Fragmented QRS (fQRS) is an easily evaluated noninvasive parameter in electrocardiograms (ECGs) for predicting cardiac adverse events. Our study aimed to evaluate whether fQRS could be used as a risk factor to predict a major adverse cardiac event (MACE) in children with idiopathic dilated cardiomyopathy (DCM). Our retrospective study enrolled 63 patients aged ≤ 19 years who were newly diagnosed with idiopathic DCM at Samsung Medical Center from 2003 to 2014, and followed up until December 2018. Demographic data, ECGs, and echocardiography were reviewed and analyzed for their possible links with adverse outcomes. The median age was 14.0 months and the median length of follow-up was 65.0 months. Age, QRS duration, and ejection fraction in M-mode at diagnosis were significantly different between the fQRS and non-fQRS groups (P = 0.026; P = 0.001; and P = 0.020). Significant difference between the fQRS and non-fQRS groups was found in patients with a MACE (P = 0.016, odd ratio 3.643) or any arrhythmias (P = 0.008, odd ratio 6.563). The MACE-free survival rate showed a significant difference in terms of fQRS (P = 0.003; P = 0.007; and P = 0.027). In univariate analyses, age, QRS duration, corrected QT, positive fQRS, and the number of leads with fQRS were significant predictors of MACEs. Among the above factors, positive fQRS at diagnosis was a strongly significant predictor of adverse outcomes in multivariate analyses (hazards ratio 94.529, P = 0.001). Fragmented QRS complex at diagnosis could be used as a strong predictor for cardiac adverse outcomes in pediatric patients with idiopathic DCM.

Influence of Optimization Design Based on Artificial Intelligence and Internet of Things on the Electrocardiogram Monitoring System

With the increasing emphasis on remote electrocardiogram (ECG) monitoring, a variety of wearable remote ECG monitoring systems have been developed. However, most of these systems need improvement in terms of efficiency, stability, and accuracy. In this study, the performance of an ECG monitoring system is optimized by improving various aspects of the system. These aspects include the following: the judgment, marking, and annotation of ECG reports using artificial intelligence (AI) technology; the use of Internet of Things (IoT) to connect all the devices of the system and transmit data and information; and the use of a cloud platform for the uploading, storage, calculation, and analysis of patient data. The use of AI improves the accuracy and efficiency of ECG reports and solves the problem of the shortage and uneven distribution of high-quality medical resources. IoT technology ensures the good performance of remote ECG monitoring systems in terms of instantaneity and rapidity and, thus, guarantees the maximum utilization efficiency of high-quality medical resources. Through the optimization of remote ECG monitoring systems with AI and IoT technology, the operating efficiency, accuracy of signal detection, and system stability have been greatly improved, thereby establishing an excellent health monitoring and auxiliary diagnostic platform for medical workers and patients.

Prospective associations between ECG abnormalities and death or myocardial infarction in a cohort of 980 employed, middle-aged Swedish men

Background

In 1993, 1000 randomly selected employed Swedish men aged 45–50 years were invited to a nurse-led health examination with a survey on life style, fasting lab tests, and a 12-lead ECG. A repeat examination was offered in 1998. The ECGs were classified according to the Minnesota Code. Upon ethical approval, endpoints in terms of MI and death over 25 years were collected from Swedish national registers with the purpose of analyzing the independent association of ECG abnormalities as risk factors for myocardial infarction and death.

Results

Seventy-nine of 977 participants had at least one ECG abnormality 1993 or 1998.

One hundred participants had a first MI over the 25 years. Odds ratio for having an MI in the group that had one or more ECG abnormality compared with the group with two normal ECGs was estimated to 3.16. 95%CI (1.74; 5.73), p value 0.0001.

One hundred fifty-seven participants had died before 2019. For death, similarly no statistically significant difference was shown, OR 1.52, 95%CI (0.83; 2.76).

Conclusions

Our study suggests that presence of ST- and R-wave changes is associated with an independent 3–4-fold increased risk of MI after 25 years follow-up, but not of death. A 12-lead resting ECG should be included in any MI risk calculation on an individual level.

Supplementary Information

The online version contains supplementary material available at 10.1186/s43044-020-00114-9.

The prognostic significance of T-wave inversion according to ECG lead group during long-term follow-up in the general population

Background

Inverted T waves in the electrocardiogram (ECG) have been associated with coronary heart disease (CHD) and mortality. The pathophysiology and prognostic significance of T‐wave inversion may differ between different anatomical lead groups, but scientific data related to this issue is scarce.

Methods

A representative sample of Finnish subjects (n = 6,354) aged over 30 years underwent a health examination including a 12‐lead ECG in the Health 2000 survey. ECGs with T‐wave inversions were divided into three anatomical lead groups (anterior, lateral, and inferior) and were compared to ECGs with no pathological T‐wave inversions in multivariable‐adjusted Fine–Gray and Cox regression hazard models using CHD and mortality as endpoints.

Results

The follow‐up for both CHD and mortality lasted approximately fifteen years (median value with interquartile ranges between 14.9 and 15.3). In multivariate‐adjusted models, anterior and lateral (but not inferior) T‐wave inversions associated with increased risk of CHD (HR: 2.37 [95% confidence interval 1.20–4.68] and 1.65 [1.27–2.15], respectively). In multivariable analyses, only lateral T‐wave inversions associated with increased risk of mortality in the entire study population (HR 1.51 [1.26–1.81]) as well as among individuals with no CHD at baseline (HR 1.59 [1.29–1.96]).

Conclusions

The prognostic information of inverted T waves differs between anatomical lead groups. T‐wave inversion in the anterior and lateral lead groups is independently associated with the risk of CHD, and lateral T‐wave inversion is also associated with increased risk of mortality. Inverted T wave in the inferior lead group proved to be a benign phenomenon.

[Association of T-wave amplitude on electrocardiogram with left ventricular ejection fraction in children with dilated cardiomyopathy]

OBJECTIVE

To study the association of T-wave amplitude on electrocardiogram (ECG) with left ventricular ejection fraction (LVEF) in children with dilated cardiomyopathy.

METHODS

A retrospective analysis was performed for the clinical data of 44 children who were diagnosed with dilated cardiomyopathy from May 2009 to June 2018. According to LVEF, they were divided into two groups: LVEF ≥50% group (n=26) and LVEF <50% group (n=18). After treatment, 25 children were followed up for 3-42 months (mean 14±9 months). The Guangdong Zhongshan SR-1000A ECG Automatic Analyzer was used to obtain the 12-lead body surface ECG results in the supine position. T-wave amplitude on ECG was evaluated by software and manual measurement.

RESULTS

Compared with the LVEF ≥50% group, the LVEF <50% group had a significant reduction in the T-wave amplitude in leads II, V4, V5 and V6 (P<0.05). The increased-LVEF group (an increase in LVEF > 5% after treatment) had a significant increase in the T-wave amplitude in leads aVR, V5, and V6 after treatment (P<0.05), while the unchanged-LVEF group (an increase in LVEF ≤ 5% after treatment) had a significant reduction in the T-wave amplitude in lead aVR after treatment (P<0.05). The receiver operating characteristic curve analysis showed that the T-wave amplitude in leads II, V4, V5 and V6 had a certain value in predicting LVEF <50% in children with dilated cardiomyopathy (P<0.05). A combination of T-wave amplitude of ≤0.20 mV in lead II, ≤0.40 mV in lead V4, and ≤0.30 mV in leads V5 and V6 had a sensitivity of 88.2% and specificity of 76.0% in the predication of LVEF <50% in children with dilated cardiomyopathy.

CONCLUSIONS

T-wave amplitude on ECG can be used as the indexes for the evaluation of the left ventricular systolic function in children with dilated cardiomyopathy.

Effect of anemia on the frontal QRS-T angle

BACKGROUND

Anemia is a common health problem worldwide and is associated with a poor prognosis for cardiovascular diseases. It can alter myocardial depolarization and repolarization by affecting the generation and propagation of electrical impulses. The frontal QRS-T angle is a novel marker of the absolute difference between myocardial depolarization and repolarization. This study investigated the effects of anemia on the frontal QRS-T angle.

METHODS

The study included 66 anemic subjects with no cardiac disorders, and 50 age- and gender-matched controls. Twelve-lead electrocardiography (ECG) was obtained for all subjects, and the frontal QRS-T angle was calculated based on the automatic report of the ECG machine.

RESULTS

Subjects with anemia had a significantly higher frontal QRS-T angle than subjects without anemia (28.9±14.1 vs. 22.5±11.8, P=0.011). In correlation analysis, the frontal QRS-T angle was positively correlated with the Body Mass Index (BMI; r=0.287, P=0.002), left ventricular mass (LVM; r=0.264, P=0.004), and heart rate (r=0.275, P=0.003) and negatively correlated with the hemoglobin level (r=-0.349, P<0.001). Multivariate regression analysis showed that the hemoglobin level (β=-0.254, tβ=-2.805, P=0.006), BMI (β=0.240, t=2.770, P=0.007), and LVM (β=0.201, t=2.303, P=0.023) were independently associated with the frontal QRS-T angle.

CONCLUSIONS

The hemoglobin level was found to be an independent predictor of the frontal QRS-T angle.

Association of ECG parameters with late gadolinium enhancement and outcome in patients with clinical suspicion of acute or subacute myocarditis referred for CMR imaging

BACKGROUND

Risk stratification of myocarditis is challenging due to variable clinical presentations. Cardiovascular magnetic resonance (CMR) is the primary non-invasive imaging modality to investigate myocarditis while electrocardiograms (ECG) are routinely included in the clinical work-up. The association of ECG parameters with CMR tissue characterisation and their prognostic value were investigated in patients with clinically suspected myocarditis.

METHODS AND RESULTS

Consecutive patients with suspected myocarditis who underwent CMR and ECG were analysed. Major adverse cardiovascular event (MACE) included all-cause death, hospitalisation for heart failure, heart transplantation, documented sustained ventricular arrhythmia, or recurrent myocarditis. A total of 587 patients were followed for a median of 3.9 years. A wide QRS-T angle, low voltage and fragmented QRS were significantly associated with late gadolinium enhancement. Further, a wide QRS-T angle, low voltage and prolonged QTc duration were associated with MACE in the univariable analysis. In a multivariable model, late gadolinium enhancement (HR: 1.90, 95%CI: 1.17-3.10; p = 0.010) and the ECG parameters of a low QRS voltage (HR: 1.86, 95%CI: 1.01-3.42; p = 0.046) and QRS-T-angle (HR: 1.01, 95%CI: 1.00-1.01; p = 0.029) remained independently associated with outcome. The cumulative incidence of MACE was incrementally higher when findings of both CMR and ECG were abnormal (p<0.001).

CONCLUSION

In patients with clinically suspected myocarditis, abnormal ECG parameters are associated with abnormal tissue characteristics detected by CMR. Further, ECG and CMR findings have independent prognostic implications for morbidity and mortality. Integrating both exams into clinical decision-making may play a role in risk stratification in this heterogeneous patient population.

Incidental abnormal ECG findings and long-term cardiovascular morbidity and all-cause mortality: A population based prospective study

BACKGROUND

The additional prognostic value of resting electrocardiogram (ECG) in long-term cardiovascular disease (CVD)-risk-assessment is unclear. We evaluated the association of incidental abnormal ECG findings with long-term CVD-risk and all-cause mortality, and assessed the additional prognostic value of ECG as a screening tool in adults without known CVD.

METHODS

A cohort of 2601 Israeli men and women without known CVD were actively followed from 1976 to 1982 for 23-year cumulative CVD-incidence, and until May 2017 for all-cause mortality. At baseline and follow-up, participants underwent interviews, physical examinations, blood tests and ECG.

RESULTS

At baseline, 1199 (46.1%) had incidental abnormal ECG findings (exposed-group). CVD cumulative incidence reached 31.6% among the 930 survivors who participated in the active follow-up (294/930). During a 31-year median follow-up, 1719 (66.1%) of the total cohort died. Incidental abnormal ECG findings were associated with 46% greater CVD-risk (odds ratio = 1.46, 95%CI = 1.09-1.97). The net reclassification improvement (NRI) of CVD-risk was 7.4% (95%CI_NRI = 1.5%-13.3%, p = 0.01) following the addition of ECG findings, but the C-index improvement was not statistically significant [C-index = 0.656 (0.619-0.694) vs. C-index = 0.666 (0.629-0.703), p = 0.14]. Multivariable Cox regression demonstrated an all-cause mortality hazard ratio (HR) of 1.18 (95%CI = 1.07-1.30) for exposed vs. unexposed individuals. Non-specific T-wave changes and left-axis deviation are the incidental ECG abnormalities that were associated with all-cause mortality [HR = 1.18 (95%CI = 1.05-1.33) and HR = 1.19 (95%CI = 1.00-1.42), respectively].

CONCLUSION

Incidental abnormal ECG findings, mainly non-specific T-wave changes and left-axis deviation, were associated with increased long-term CVD-risk and all-cause mortality among individuals without known CVD, and demonstrated net reclassification improvement for CVD-risk.

Changes on the electrocardiogram in anorexia nervosa: A case control study

PURPOSE

Anorexia nervosa is a complex psychiatric condition with increased mortality. The electrocardiogram (ECG) may show repolarization changes which may associate with an increased risk of sudden death. Up to 80% of patients may be prescribed psychopharmacotherapies which alter the ECG, potentially compounding arrhythmic risk. This study aimed to describe and improve understanding of ECG changes in eating disorders and assess the effect of psychopharmacotherapies.

METHODS

Adolescent patients diagnosed with anorexia nervosa were reviewed. ECGs were reviewed by blinded expert reviewers, and repolarization parameters were compared to healthy controls. Patients on and off psychopharmacotherapies were compared.

RESULTS

Thirty-eight anorexia nervosa patients off psychopharmacotherapies were age matched to 53 healthy controls. Heart rate was lower in anorexia nervosa patients (56 vs. 74 bpm, p < 0.001). The absolute QT interval was longer in patients compared to controls (408 vs. 383 ms, p < 0.001), but the QTc by Hodges' formula was similar between groups (401 vs. 408 ms, p = 0.16). The prevalence of T-wave flattening and inversion was also similar between groups (13% vs. 4%, p = 0.12) and T-peak to T-end interval (Tpe) was shorter in patients compared to controls (p < 0.01). ECG parameters were similar between patients on and off psychopharmacotherapies aside from off-drug patients showing lower HR (56 vs. 65, p = 0.04).

CONCLUSIONS

Autonomic and repolarization changes are evident on the ECG of anorexia nervosa patients, though the QTc interval was in fact similar between groups. Changes in T-wave morphology and duration may be promising metrics of repolarization effects of anorexia nervosa.

Global electrical heterogeneity as a predictor of cardiovascular mortality in men and women

Aims

The aim of this study was to investigate the contribution of depolarization and repolarization abnormalities, specially abnormalities in global electrical heterogeneity of heart in cardiovascular disease (CVD) and all-cause mortality.

Methods and results

Eight hundred and forty men and 911 women, average age of 63 years participated in this study with average follow-up was 14 years. Six electrocardiogram/vector electrocardiogram (ECG/VECG) markers QRS-duration, QTc-interval, QRST-angle, sum of absolute QRST integral (SAI QRST), T-wave roundness, and TV1-amplitude were estimated from VECG measurements. Hazard ratios (HRs) for CVD events (164 deaths) and all-cause mortality (383 deaths) for ECG parameters were calculated. Electrocardiogram or vector electrocardiogram parameter models adjusted for risk clinical factors showed that strongest predictors for CVD mortality were QRST-angle (HR 3.44, 95% confidence interval 2.12-5.36), QTc-interval (2.72, 1.73-4.29), and T-wave roundness (2.09, 1.26-3.46) among men. The strongest ECG/VECG parameters for CVD death were QRST-angle (2.47, 1.37-4.45), SAI QRST (2.37, 1.23-4.6), and QTc-interval (2.15, 1.16-4.01) among female participants. Multivariable adjusted models revealed that strongest independent ECG predictors for CVD death were QRST-angle, QTc-interval, resting heart rate, and T-roundness for men, QRST-angle and SAI QRST for women. QRST-angle, QTc-interval, resting heart rate, and T-roundness were associated with all-cause mortality in male population, although none of the ECG/VECG parameters predicted all-cause mortality among women.

Conclusion

Characteristics of global electrical heterogeneity QRST-angle and QTc-interval in men and QRST-angle and SAI QRST among females were strong and independent risk markers for cardiovascular mortality. These parameters provide new additional ECG tools for cardiovascular risk stratification.

Superior grey relational analysis on blood lipids and hematological parameters

Purpose

The purpose of this paper is to investigate the superior relationship between blood lipid- and cardiovascular disease (CVD)-related hematological parameters using superior grey relational analysis (GRA).

Design/methodology/approach

A total of 294 individuals who underwent simultaneous routine blood examination and blood lipid examination in the Physical Examination Center of the First Affiliated Hospital of Shantou University Medical College were included in this study. Superior GRA was performed to find out the superior factor in CVD-related hematological parameters and blood lipids. CVD-related hematological parameters included red blood cell distribution width, white cell count, and platelet count, platelet distribution width, mean platelet volume, as well as platelet crit. The indicators of blood lipids analyzed here consist of low-density lipoprotein, high-density lipoprotein, triglyceride and total cholesterol.

Findings

The results showed that all the grey relational degree of hematological parameters and blood lipids were over 0.8; the superior factor in hematological parameters was PLT, whereas TC was the superior factor in blood lipids.

Practical implications

Findings of this study suggested that hematological parameters are closely related to blood lipids and a potential role for hematological parameters in the prediction of dyslipidemia, which need further study; TC has the greatest influence on hematological parameters, whereas TG displays a minimal impact.

Originality/value

To the authors’ best knowledge, it was the first study to analyze the relationship between various CVD-related hematological parameters and blood lipids via superior GRA.

Trends in electrocardiographic abnormalities and risk of cardiovascular mortality in Lithuania, 1986-2015

Background

This study aimed to assess the trends in the prevalence of electrocardiographic (ECG) abnormalities from 1986 to 2015 and impact of ECG abnormalities on risk of death from cardiovascular diseases (CVD) in the Lithuanian population aged 40–64 years.

Methods

Data from four surveys carried out in Kaunas city and five randomly selected municipalities of Lithuania were analysed. A resting ECG was recorded and CVD risk factors were measured in each survey. ECG abnormalities were evaluated using Minnesota Code (MC). Trends in age-standardized prevalence of ECG abnormalities were estimated for both sexes. Multivariate Cox proportional hazards models were used to estimate hazard ratios (HR) for coronary heart disease (CHD) and CVD mortality. Net reclassification index (NRI), integrated discrimination improvement and other indices were used for evaluation of improvement in the prediction of CVD and CHD mortality risk after addition of ECG abnormalities variable to Cox models.

Results

From1986 to 2008, the decrease in the prevalence of Q-QS MC was observed in both genders. The prevalence of high R waves increased in men, while the prevalence of ST segment and T wave abnormalities as well as arrhythmias decreased in women. Ischemic changes and possible MI were associated with a 2.5-fold and 4.4-fold higher risk of death from CVD in men and 1.51-fold and 2.56-fold higher mortality risk from CVD in women as compared to individuals with marginal or no ECG abnormalities. The addition of ECG abnormalities to traditional CVD risk factors improved Cox regression models performance. According to NRI, 18.6% of men were correctly reclassified in CVD mortality prediction model and 25.2% of men - in CHD mortality prediction model.

Conclusions

the decreasing trends in the prevalence of ischemia on ECG in women and increasing trends in the prevalence of left VH in men were observed. ECG abnormalities were associated with higher risk of CVD mortality. The addition of ECG abnormalities to the prediction models modestly improved the prediction of CVD mortality beyond traditional CVD risk factors. The use of ECG as routine screening to identify high risk individuals for more intensive preventive interventions warrants further research.

A comprehensive evaluation of the genetic architecture of sudden cardiac arrest

Aims

Sudden cardiac arrest (SCA) accounts for 10% of adult mortality in Western populations. We aim to identify potential loci associated with SCA and to identify risk factors causally associated with SCA.

Methods and results

We carried out a large genome-wide association study (GWAS) for SCA (n = 3939 cases, 25 989 non-cases) to examine common variation genome-wide and in candidate arrhythmia genes. We also exploited Mendelian randomization (MR) methods using cross-trait multi-variant genetic risk score associations (GRSA) to assess causal relationships of 18 risk factors with SCA. No variants were associated with SCA at genome-wide significance, nor were common variants in candidate arrhythmia genes associated with SCA at nominal significance. Using cross-trait GRSA, we established genetic correlation between SCA and (i) coronary artery disease (CAD) and traditional CAD risk factors (blood pressure, lipids, and diabetes), (ii) height and BMI, and (iii) electrical instability traits (QT and atrial fibrillation), suggesting aetiologic roles for these traits in SCA risk.

Conclusions

Our findings show that a comprehensive approach to the genetic architecture of SCA can shed light on the determinants of a complex life-threatening condition with multiple influencing factors in the general population. The results of this genetic analysis, both positive and negative findings, have implications for evaluating the genetic architecture of patients with a family history of SCA, and for efforts to prevent SCA in high-risk populations and the general community.

Electrocardiogram as a predictor of sudden cardiac death in middle-aged subjects without a known cardiac disease

Background

Abnormal 12‑lead electrocardiogram (ECG) findings and proposing its ability for enhanced risk prediction, majority of the studies have been carried out with elderly populations with prior cardiovascular diseases. This study aims to denote the association of sudden cardiac death (SCD) and various abnormal ECG morphologies using middle-aged population without a known cardiac disease.

Methods

In total, 9511 middle-aged subjects (mean age 42 ± 8.2 years, 52% males) without a known cardiac disease were included in this study. Risk for SCD was assessed after 10 and 30-years of follow-up.

Results

Abnormal ECG was present in 16.3% (N = 1548) of subjects. The incidence of SCD was distinctly higher among those with any ECG abnormality in 10 and 30-year follow-ups (1.7/1000 years vs. 0.6/1000 years, P < 0.001; 3.4/1000 years vs. 1.9/1000 years, P < 0.001). At 10-year point, competing risk multivariate regression model showed HR of 1.62 (95% CI 1.0–2.6, P = 0.05) for SCD in subjects with abnormal ECG. QRS duration ≥ 110 ms, QRST-angle > 100°, left ventricular hypertrophy, and T-wave inversions were the most significant independent ECG risk markers for 10-year SCD prediction with up to 3-fold risk for SCD. Those with ECG abnormalities had a 1.3-fold risk (95% CI 1.07–1.57, P = 0.007) for SCD in 30-year follow-up, whereas QRST-angle > 100°, LVH, ER ≥ 0.1 mV and ≥0.2 mV were the strongest individual predictors. Subjects with multiple ECG abnormalities had up to 6.6-fold risk for SCD (P < 0.001).

Conclusion

Several ECG abnormalities are associated with the occurrence of early and late SCD events in the middle-age subjects without known history of cardiac disease.

Body mass index, abdominal fatness, and the risk of sudden cardiac death: a systematic review and dose-response meta-analysis of prospective studies

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.

Comparison of QRS Duration and Associated Cardiovascular Events in American Indian Men Versus Women (The Strong Heart Study)

Electrocardiographic QRS duration at rest is associated with sudden cardiac death and death from coronary heart disease in the general population. However, its relation to cardiovascular events in American Indians, a population with persistently high cardiovascular disease mortality, is unknown. The relation of QRS duration to incident cardiovascular disease during 17.2 years of follow-up was assessed in 1,851 male and female Strong Heart Study participants aged 45 to 74 years without known cardiovascular disease at baseline. Cox regression with robust standard error estimates was used to determine the association between quintiles of QRS duration and incident cardiovascular disease in gender-stratified analyses, adjusted for age, systolic blood pressure, hypertension, antihypertensive medication use, body mass index, current smoking, diabetes, total cholesterol, high-density lipoprotein cholesterol, and albuminuria. In women only, QRS duration in the highest quintile (≥105 ms) conferred significantly higher risk of cardiovascular disease than QRS duration in the lowest quintile (64 to 84 ms) (hazard ratio 1.6, 95% CI 1.1 to 2.4) likely because of higher risks of coronary heart disease (hazard ratio 1.8, 95% CI 1.1 to 3.1) and myocardial infarction (hazard ratio 2.1, 95% CI 1.0 to 4.7). Furthermore, when added to the Strong Heart Study Coronary Heart Disease Risk Calculator, QRS duration significantly improved prediction of future coronary heart disease events in women (Net Reclassification Index 0.17, 95% CI 0.06 to 0.47). In conclusion, QRS duration is an independent predictor of cardiovascular disease in women in the Strong Heart Study cohort and may have value in estimating risk in populations with similar risk profiles and a high lifetime incidence of cardiovascular disease.

Continuous ECG Monitoring in Patients With Acute Coronary Syndrome or Heart Failure: EASI Versus Gold Standard

The purpose of the study was to compare the EASI system with the standard 12-lead surface electrocardiogram (ECG) for the accuracy in detecting the main electrocardiographic parameters (J point, PR, QT, and QRS) commonly monitored in patients with acute coronary syndromes or heart failure. In this observational comparative study, 253 patients who were consecutively admitted to the coronary care unit with acute coronary syndrome or heart failure were evaluated. In all patients, two complete 12-lead ECGs were acquired simultaneously. A total of 6,072 electrocardiographic leads were compared (3,036 standard and 3,036 EASI). No significant differences were found between the investigate parameters of the two measurement methods, either in patients with acute coronary syndrome or in those with heart failure. This study confirmed the accuracy of the EASI system in monitoring the main ECG parameters in patients admitted to the coronary care unit with acute coronary syndrome or heart failure.

Distinguishing between those dying suddenly or not suddenly from coronary heart disease: long-term prospective results from the Northwick Park Heart Study

AIM

To establish whether ECG findings are associated with subsequent risk of sudden death from coronary heart disease (CHD).

METHODS AND RESULTS

Potential risk factors for CHD were measured at entry to the first Northwick Park Heart Study of 2167 men. ECG findings were coded as high or low risk for CHD according to definitions in the Minnesota code. Sudden or non-sudden deaths were defined as occurring in less than or more than 24 hours, respectively. The only factor independently associated with sudden death among the 262 men dying of CHD was high-risk ECG. Of 184 sudden CHD deaths, 34 men (18.5%) had had high-risk ECGs at entry to the study compared with 5 (6.4%) of 78 men who experienced non-sudden deaths (adjusted OR 3.94 (95% CI 1.33 to 11.67)) (p=0.006). Findings were also compared among all 2167 men, where high-risk ECGs were again associated with sudden death. T-wave changes were the main abnormalities associated with a high risk of sudden death.

CONCLUSIONS

In a group of men who had not previously experienced major episodes of CHD but who subsequently died from it, there was strong evidence that high-risk ECG changes, mainly T-wave abnormalities, differentiated between those who later died sudden deaths and those who survived for >24 hours.

Sudden Cardiac Risk Stratification with Electrocardiographic Indices - A Review on Computational Processing, Technology Transfer, and Scientific Evidence

Great effort has been devoted in recent years to the development of sudden cardiac risk predictors as a function of electric cardiac signals, mainly obtained from the electrocardiogram (ECG) analysis. But these prediction techniques are still seldom used in clinical practice, partly due to its limited diagnostic accuracy and to the lack of consensus about the appropriate computational signal processing implementation. This paper addresses a three-fold approach, based on ECG indices, to structure this review on sudden cardiac risk stratification. First, throughout the computational techniques that had been widely proposed for obtaining these indices in technical literature. Second, over the scientific evidence, that although is supported by observational clinical studies, they are not always representative enough. And third, via the limited technology transfer of academy-accepted algorithms, requiring further meditation for future systems. We focus on three families of ECG derived indices which are tackled from the aforementioned viewpoints, namely, heart rate turbulence (HRT), heart rate variability (HRV), and T-wave alternans. In terms of computational algorithms, we still need clearer scientific evidence, standardizing, and benchmarking, siting on advanced algorithms applied over large and representative datasets. New scenarios like electronic health recordings, big data, long-term monitoring, and cloud databases, will eventually open new frameworks to foresee suitable new paradigms in the near future.

Electrocardiographic T Wave Abnormalities and the Risk of Sudden Cardiac Death: The Finnish Perspective

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.

Spatial/Frontal QRS-T Angle Predicts All-Cause Mortality and Cardiac Mortality: A Meta-Analysis

BACKGROUND

A number of studies have assessed the predictive effect of QRS-T angles in various populations since the last decade. The objective of this meta-analysis was to evaluate the prognostic value of spatial/frontal QRS-T angle on all-cause death and cardiac death.

METHODS

PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials were searched from their inception until June 5, 2014. Studies reporting the predictive effect of spatial/frontal QRS-T angle on all-cause/cardiac death in all populations were included. Relative risk (RR) was used as a measure of effect.

RESULTS

Twenty-two studies enrolling 164,171 individuals were included. In the combined analysis in all populations, a wide spatial QRS-T angle was associated with an increase in all-cause death (maximum-adjusted RR: 1.40; 95% confidence interval [CI]: 1.32 to 1.48) and cardiac death (maximum-adjusted RR: 1.71; 95% CI: 1.54 to 1.90), a wide frontal QRS-T angle also predicted a higher rate of all-cause death (maximum-adjusted RR: 1.71; 95% CI: 1.54 to 1.90). Largely similar results were found using different methods of categorizing for QRS-T angles, and similar in subgroup populations such as general population, populations with suspected coronary heart disease or heart failure. Other stratified analyses and meta-analyses using unadjusted data also generated consistent findings.

CONCLUSIONS

Spatial QRS-T angle held promising prognostic value on all-cause death and cardiac death. Frontal QRS-T angle was also a promising predictor of all-cause death. Given the good predictive value of QRS-T angle, a combined stratification strategy in which QRS-T angle is of vital importance might be expected.

Electrocardiographic Predictors of Cardiovascular Mortality

Cardiovascular diseases are the main causes of mortality. Sudden cardiac death may also appear in athletes, due to underlying congenital or inherited cardiac abnormalities. The electrocardiogram is used in clinical practice and clinical trials, as a valid, reliable, accessible, inexpensive method. The aim of the present paper was to review electrocardiographic (ECG) signs associated with cardiovascular mortality and the mechanisms underlying those associations, providing a brief description of the main studies in this area, and consider their implication for clinical practice in the general population and athletes. The main ECG parameters associated with cardiovascular mortality in the present paper are the P wave (duration, interatrial block, and deep terminal negativity of the P wave in V1), prolonged QT and Tpeak-Tend intervals, QRS duration and fragmentation, bundle branch block, ST segment depression and elevation, T waves (inverted, T wave axes), spatial angles between QRS and T vectors, premature ventricular contractions, and ECG hypertrophy criteria.

Changes of Virtual Planar QRS and T Vectors Derived from Holter in the Populations with and without Diabetes Mellitus

Aims

Research related to type 2 diabetes mellitus (DM) and parameters of electrocardiography (ECG) was limited. Patients with and without DM (NDM) were randomly enrolled in a study to exploit the influence of DM on planar QRS and T vectors derived from the Virtual Holter process.

Methods

A total of 216 (NDM) and 127 DM patients were consecutively and randomly recruited. We selected a 1‐minute length of ECG, which was scheduled for analysis at 4 AM. After a series of calculating algorisms, we received the virtual planar vector parameters.

Results

Patients with DM were elderly (65.61 ± 12.08 vs 59.41 ± 16.86 years, P < 0.001); higher morbidity of hypertension (76.38% vs 58.14%, P < 0.001) and coronary artery disease (44.09% vs 32.41%, P = 0.03); thicker interventricular septum (10.92 ± 1.77 vs 10.08 ± 1.96 mm, P < 0.001) and left ventricular posterior wall (9.84 ± 1.38 vs 9.39 ± 1.66 mm, P = 0.03); higher lipid levels and average heart rate (66.67 ± 12.04 vs 61.87 ± 13.36 bpm, P < 0.01); higher angle of horizontal QRS vector (HQRSA, –2.87 ± 48.48 vs –19.00 ± 40.18 degrees, P < 0.01); lower maximal magnitude of horizontal T vector (HTV, 2.33 ± 1.47 vs 2.88 ± 1.89 mm, P = 0.01) and maximal magnitude of right side T vector (2.77 ± 1.55 vs 3.27 ± 1.92 mm, P = 0.03), and no difference in angle of frontal QRS‐T vector (FQRSTA, 32.77 ± 54.20 vs 28.39 ± 52.87 degrees, P = 0.74) compared with patients having NDM. After adjusting for confounding factors, DM was significantly effective on FQRSTA (regression coefficient –40.0, 95%CI –66.4 to –13.6, P < 0.01), HQRSA (regression coefficient 22.6, 95%CI 2.5 to 42.8, P = 0.03), and HTV (regression coefficient 0.9, 95%CI 0.2 to 1.7, P = 0.01). Confounding factors included: sex, 2‐hour postprandial blood glucose, smoking, triglyceride, apolipoprotein A, creatinine, left ventricular ejection fraction, and average heart rate.

Conclusions

The risk factors of DM and lipid metabolism abnormality particularly apolipoprotein A significantly modified parameters of virtual planar QRS and T vector, including frontal QRS‐T angle.

Preoperative frontal QRS-T angle is an independent correlate of hospital length of stay and predictor of haemodynamic support requirement following off-pump coronary artery bypass graft surgery

OBJECTIVES

With the adoption of novel operative techniques and aggressive care protocols that facilitate earlier extubation and mobilization of patients, postoperative length of stay (LOS) following coronary artery bypass graft surgery (CABG) has declined. However, there is paucity of information regarding preoperative electrocardiographic predictors of LOS following CABG. In this study, we investigated whether frontal QRS-T angle, which is an abnormal repolarization marker in prediction of various cardiovascular events, was an independent correlate of postoperative hospital LOS for off-pump CABG. Furthermore, we evaluated independent predictors of vasopressor agent/intra-aortic balloon pump (IABP) support requirement following off-pump CABG.

METHODS

In this observational study, 78 patients with stable angina, who were scheduled for elective coronary artery bypass surgery following diagnosis of obstructive coronary artery disease by conventional angiography, were enrolled.

RESULTS

Left ventricular ejection fraction (LVEF) was significantly lower and vasopressor agent/IABP support requirement and incidence of sustained atrial or ventricular arrhythmias was higher in patients with wide QRS-T angle (P < 0.05). Postoperative hospital LOS was also longer in this group. From the preoperative characteristics, wide frontal QRS-T angle was found to be an independent correlate of postoperative hospital LOS (B ± SD: 11.97 ± 0.62, P ≤ 0.01). Wide frontal QRS-T angle was also found to be an independent predictor of vasopressor agent/IABP support requirement postoperatively (OR: 7.87, P ≤ 0.01).

CONCLUSIONS

Prediction of the hospital LOS and patient outcome following CABG is of great importance. Being easily obtainable via standard 12-lead electrocardiogram and its low cost may make frontal QRS-T angle a beneficial marker for reducing both patient-based morbidity and economic burden.

T-wave inversion and mortality risk

OBJECTIVE

To investigate the predictive value of T-wave inversion (TWI) on routine electrocardiogram (ECG) for mortality in the general population with various risk groups in a prospective population-based follow-up study. Subjects. ECGs of a random population-based sample of 1814 men aged 42-60 years without coronary heart disease (CHD) at baseline.

RESULTS

During an average follow-up of 21 years, 685 deaths occurred. Of these deaths 174 were due to CHD and 278 to cardiovascular disease (CVD). There were 57 subjects with TWI. After adjusting for age, TWI was associated with an increased CHD mortality (relative risk (RR) 4.10, 95% CI 2.26-7.41), CVD mortality (RR 3.47, 95% CI 2.09-5.78), and all-cause mortality (RR 2.07, 95% CI 1.37-3.12). After further adjustment for conventional risk factors, TWI remained statistically significant, predicting CHD mortality (RR 2.62, 95% CI 1.57-4.36), CVD mortality (RR 2.18, 95% CI 1.40-3.38), and all-cause mortality (RR 1.41, 95% CI 1.00-2.01), respectively.

CONCLUSION

TWI is a strong predictor for CHD, CVD, and all-cause mortality in the general population. The respective risks of CHD and CVD among men with TWI were also increased among men with high blood pressure, LDL cholesterol, and obesity.

Electrocardiographic repolarization-related variables as predictors of coronary heart disease death in the women's health initiative study

BACKGROUND

We evaluated 25 repolarization-related ECG variables for the risk of coronary heart disease (CHD) death in 52 994 postmenopausal women from the Women's Health Initiative study.

METHODS AND RESULTS

Hazard ratios from Cox regression were computed for subgroups of women with and without cardiovascular disease (CVD). During the average follow-up of 16.9 years, 941 CHD deaths occurred. Based on electrophysiological considerations, 2 sets of ECG variables with low correlations were considered as candidates for independent predictors of CHD death: Set 1, Ѳ(Tp|Tref), the spatial angle between T peak (Tp) and normal T reference (Tref) vectors; Ѳ(Tinit|Tterm), the angle between the initial and terminal T vectors; STJ depression in V6 and rate-adjusted QTp interval (QTpa); and Set 2, TaVR and TV1 amplitudes, heart rate, and QRS duration. Strong independent predictors with over 2-fold increased risk for CHD death in women with and without CVD were Ѳ(Tp|Tref) >42° from Set 1 and TaVR amplitude >-100 μV from Set 2. The risk for these CHD death predictors remained significant after multivariable adjustment for demographic/clinical factors. Other significant predictors for CHD death in fully adjusted risk models were Ѳ(Tinit|Tterm) >30°, TV1 >175 μV, and QRS duration >100 ms.

CONCLUSIONS

Ѳ(Tp|Tref) angle and TaVR amplitude are associated with CHD mortality in postmenopausal women. The use of these measures to identify high-risk women for further diagnostic evaluation or more intense preventive intervention warrants further study.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00000611.