Screening entire healthcare system ECG database: Association of deep terminal negativity of P wave in lead V1 and ECG referral with mortality

The clinical value of P-wave terminal force in lead V1 in evaluating pericardial thickness in tuberculous constrictive pericarditis

AIM

To investigate the relationship between p wave terminal force (Ptfv1) and pericardial thickness in patients with tuberculous constrictive pericarditis.

METHODS

From January 2018 to October 2022, 95 patients with tuberculous constrictive pericarditis who needed pericarditis dissection in a hospital were collected, and 3 patients who did not meet the criteria were excluded, a total of 92 cases. The absolute value of Ptfv1 in conventional electrocardiogram was tested before surgery, and pericardial thickness was measured by echocardiography and chest CT. Pericardial thickness was measured after pericardial dissection. Pearson correlation analysis was used, R software was used to make scatter plot, and non-parametric square test was used. The correlation of postoperative measurements with echocardiography, chest CT and absolute value of Ptfv1 was analyzed.

RESULTS

Pearson correlation analysis was conducted with postoperative measurements and echocardiography measurements, postoperative measurements and chest CT measurements, and postoperative measurements and absolute value of Ptfv1. Pearson correlation analysis showed that the correlation coefficients between postoperative measurements and echocardiography, chest CT and Ptfv1 values were statistically significant. Scatter plot and nonparametric Chi-square test showed that postoperative measurements were consistent with absolute values of echocardiography, chest CT and Ptfv1 (p < 0.05). And this study found that the distribution of the value of Ptfv1 ≥ 5 was higher than the value of Ptfv1 < 5 after pericardiectomy (0.95:0.05) in the absolute value of Ptfv1 ≥ 0.04 which measured before pericardiectomy. The hypothesis was statistically significant (p < 0.05).

CONCLUSION

The absolute value of Ptfv1 in electrocardiogram can be used as an auxiliary diagnostic index to evaluate pericardial thickness in tuberculous constrictive pericarditis.

A short P-wave duration is associated with incident heart failure in the elderly: a 15 years follow-up cohort study

BACKGROUND

Early identification of patients at risk of congestive heart failure (HF) may alter their poor prognosis. The aim was therefore to test whether simple electrocardiographic variables, the P-wave and PR-interval, could predict incident HF.

METHODS

The PIVUS (Prospective Investigation of the Vasculature in Uppsala Seniors) study (1016 individuals all aged 70 years, 50% women) was used to identify predictors of HF. Subjects with prevalent HF, QRS duration ≥ 130 ms, atrial tachyarrhythmias, implanted pacemaker/defibrillator, second- and third-degree atrioventricular block or delta waves at baseline were excluded. Cox proportional hazard analysis was used to relate the PR interval, P-wave duration (Pdur) and amplitude (Pamp), measured in lead V1, to incident HF. Adjustment was performed for gender, RR-interval, beta-blocking agents, systolic blood pressure, body mass index and smoking.

RESULTS

Out of 836 subjects at risk, 107 subjects were diagnosed with HF during a follow-up of 15 years. In the multivariate analysis, there was a strong U-shaped correlation between Pdur in lead V1 and incident HF (P = 0.0001) which was significant for a Pdur < 60 ms [HR = 2.75; 95% CI: 1.87-4.06, at Pdur 40 ms] but not for prolonged Pdur. There was no significant relationship between incident HF and the PR-interval or the Pamp. A Pdur < 60 ms improved discrimination by 3.7% when added to the traditional risk factors including sex, RR-interval, beta-blocking agents, systolic blood pressure, BMI and smoking (P = 0.048).

CONCLUSIONS

A short Pdur, an easily measured parameter on the ECG, may potentially be a useful marker of future HF, enabling its early detection and prevention, thus improving outcomes.

Harmful Impact of Tobacco Smoking and Alcohol Consumption on the Atrial Myocardium

Tobacco smoking and alcohol consumption are widespread exposures that are legal and socially accepted in many societies. Both have been widely recognized as important risk factors for diseases in all vital organ systems including cardiovascular diseases, and with clinical manifestations that are associated with atrial dysfunction, so-called atrial cardiomyopathy, especially atrial fibrillation and stroke. The pathogenesis of atrial cardiomyopathy, atrial fibrillation, and stroke in context with smoking and alcohol consumption is complex and multifactorial, involving pathophysiological mechanisms, environmental, and societal aspects. This narrative review summarizes the current literature regarding alterations in the atrial myocardium that is associated with smoking and alcohol.

Relationship between resting 12-lead electrocardiogram and all-cause death in patients without structural heart disease: Shinken Database analysis

Background

Resting 12-lead electrocardiography is widely used for the detection of cardiac diseases. Electrocardiogram readings have been reported to be affected by aging and, therefore, can predict patient mortality.

Methods

A total of 12,837 patients without structural heart disease who underwent electrocardiography at baseline were identified in the Shinken Database among those registered between 2010 and 2017 (n = 19,170). Using 438 electrocardiography parameters, predictive models for all-cause death and cardiovascular (CV) death were developed by a support vector machine (SVM) algorithm.

Results

During the observation period of 320.4 days, 55 all-cause deaths and 23 CV deaths were observed. In the SVM prediction model, the mean c-statistics of 10 cross-validation models with training and testing datasets were 0.881 ± 0.027 and 0.927 ± 0.101, respectively, for all-cause death and 0.862 ± 0.029 and 0.897 ± 0.069, respectively for CV death. For both all-cause and CV death, high values of permutation importance in the ECG parameters were concentrated in the QRS complex and ST-T segment.

Conclusions

Parameters acquired from 12-lead resting electrocardiography could be applied to predict the all-cause and CV deaths of patients without structural heart disease. The ECG parameters that greatly contributed to the prediction were concentrated in the QRS complex and ST-T segment.

Roles of Morris Index on Poor Outcomes in Patients with Non-ST Segment Elevation Acute Coronary Syndrome

Background

This study aimed to assess the roles of the Morris index in predicting poor outcomes in patients with non-ST segment elevation acute coronary syndrome (NSTE-ACS).

Material/Methods

This study included 905 patients with newly diagnosed NSTE-ACS. The Morris index, also known as P wave terminal force in lead V1 (PTFV1), was recorded at admission and discharge. PTVF1 (+) was defined as an absolute value >0.04 mm·s, while PTFV1 (−) was defined as an absolute value <0.04 mm·s. Based on their PTFV1 values at admission/discharge, patients were divided into 4 groups: PTFV1 (−)/(−), PTFV1 (+)/(−), PTFV1 (−)/(+), and PTFV1 (+)/(+). Univariate and multivariate regression analyses were utilized to identify the variables that could contribute to NSTE-ACS risk.

Results

Compared with the PTFV1 (−)/(−) group, the incidence of poor outcomes was significantly higher in the PTFV1 (−)/(+) (hazard ratio [HR], 3.548; 95% confidence interval [95% CI], 2.024–6.219) and PTFV1 (+)/(+) (HR, 2.133; 95% CI, 1.141–3.986) groups, but not statistically different in the PTFV1 (+)/(−) group (risk ratio, 0.983; 95% CI, 0.424–2.277).

Conclusions

Primary PTFV1 (+) at discharge and PTFV1 (+) during hospitalization were independent risk factors for poor outcomes, which may provide useful prognostic information for patients with NSTE-ACS.

Elevated red cell distribution width is associated with negative P wave amplitude in lead V1: national health and nutrition examination survey (NHANES III)

INTRODUCTION

Red cell distribution (RDW) is associated with atrial fibrillation (AF) incidence. However, its relationship with precursors of AF has not been established. We aim to investigate if association exists between RDW and negative P wave amplitude in V1, a marker of left atrial abnormality.

METHODS

NHANES III is a complex, multistage, clustered design survey of noninstitutionalized United States population between 1988-94. A Sample of 6403 individuals was extracted after excluding missing demographic, laboratory, anthropometric and ECG data and major ECG abnormalities. Variables were selected and univariate analysis was done first with a level of significance at P<0.01 (99% confidence). All the significant variables were included in a multivariate linear regression model.

RESULTS

53.58% of subjects were female. Racial distribution was caucasian 50.2%, hispanic 23.9% and african american 21.7%. Age, PR interval, heart rate, systolic blood pressure, red cell distribution width, glycated hemoglobin, serum cholesterol, serum ferritin, and body mass index showed a significant correlation with negative P wave amplitude in V1 (P<0.001). After including all these variables in a multivariate regression model, only age, body mass index, systolic blood pressure, PR interval, heart rate and red cell distribution width had a P≤0.001.

CONCLUSIONS

Increased RDW is independently associated with negative P wave amplitude in V1 after correcting for other cardiovascular risk factors. Further studies are required to analyze the reason for this correlation.

ECG conduction disturbances and ryanodine receptor expression levels in occupational lead exposure workers

Objectives

A significant number of researches have evidenced that occupational lead (Pb) exposure increased risks of cardiovascular disease. However, evidences about the potential effects of Pb on the cardiac conduction system are sparse and inconclusive. Besides, ryanodine receptors (RyRs) induced dysfunction of cardiac excitation contraction coupling which is considered to be one of the mechanisms in cardiovascular diseases. Therefore, we examined the association between occupational Pb exposure and ECG conduction abnormalities, as well as RyRs in Pb-induced ECG abnormalities.

Methods

We investigated 529 Pb smelter workers, and measured blood lead (BPb), zinc protoporphyrin (ZPP), ECG outcomes and RyR expression levels. Based on BPb levels, the workers were divided into three groups: the BPb not elevated group, the BPb elevated group and the Pb poisoning group. Descriptive and multivariable analyses were performed.

Results

Compared with the BPb not elevated group, the Pb poisoning group had a higher incidence of high QRS voltage, and a lower level of RyR1 gene expression (p<0.05). Further unconditional multivariable logistic regression analyses showed that high QRS voltage was positively related to BPb (OR=1.045, 95% CI 1.014 to 1.078) and inversely associated with RyR1 expression (OR=0.042, 95% CI 0.002 to 0.980) after adjusting for potential confounders. In addition, multiple linear regression analyses showed that the QTc interval was positively associated with ZPP (β=0.299, 95% CI 0.130 to 0.468) after adjusting for potential confounders.

Conclusions

Our study provided evidences that occupational exposure to Pb may be associated with worse ECG outcomes (high QRS voltage), which might be related to decreased levels of RyR1.

Readily available ECG databases

Medical databases are an essential tool in health research that have become more frequently used in the last few decades alongside the growth and worldwide availability of the internet. Heart diseases are one of the most common health problems in the world with a vast amount of work being done on disease prevention and surveillance. With respect to arrhythmia detection, the electrocardiogram (ECG) is one of the most studied monitoring tools to date, generating large amounts of real-time data and giving rise to readily available ECG databases. In this research, we provide an overview of the most cited ECG databases with public/read access and discuss their characteristics with emphasis on the ECG records, as well as their use and applications carried out by other researchers around the world.

P-wave terminal force in lead V1 is a predictive indicator for the diagnosis of tuberculous constrictive pericarditis

OBJECTIVES

The purpose of this study is to explore the value of P-wave terminal force in lead V1 (PTFV1) in the clinical diagnosis of tuberculous constrictive pericarditis (TCP).

METHODS

A total of 53 patients with TCP and 64 patients with tuberculous exudative pericarditis were enrolled in this retrospective study. The demographic and clinical characteristics were collected, including gender, age, the course of disease and New York Heart Association (NYHA) classification. Besides, echocardiography data also were obtained, including left atrial diameter, left ventricular end-diastolic diameter and left ventricular ejection fraction. In addition, the parameters of electrocardiogram (ECG) were obtained, such as heart rate, the time from the corrected ORS wave origin to T-wave terminal, atrial fibrillation, right bundle branch block, atrial premature beat, and PTFV1 value.

RESULTS

No significant differences were found in age, gender, the course of disease, echocardiography results, ECG parameters (in addition to PTFV1) between patients with TCP and patients with tuberculous exudative pericarditis. The percentage of patients located in NYHA class IV in the patients with TCP was significantly higher than those of patients with tuberculous exudative pericarditis (p = 0.041). Moreover, the incidence rate of abnormal PTFV1 (≤ -0.04 mm·s) was obviously higher in patients with TCP than those of patients with tuberculous exudative pericarditis (64.2% vs 9.4%, p < 0.001).

CONCLUSIONS

Abnormal PTFV1 (≤ -0.04 mm·s) is associated with TCP, and PTFV1 may be a potential novel diagnostic indicator for TCP diagnosis.

Electrocardiographic left atrial abnormalities predict cardiovascular mortality

OBJECTIVE

Clinical utilization of electrocardiography for diagnosis of left atrial abnormalities is hampered by variable P-wave morphologies, multiple empiric criteria, and lack of an imaging "gold standard". Our aim was to determine the prevalence of P-wave patterns and demonstrate which components have associations with cardiovascular death (CVD).

METHODS

This is a retrospective analysis of 20,827 veterans <56 years of age who underwent electrocardiograms at a Veteran's Affairs Medical Center from 1987 to 1999, followed for a median duration of 17.8 years for CVD. Receiver Operating Characteristic, Kaplan-Meier and Cox Hazard analyses were applied, the latter with adjustment for age, gender and electrocardiography abnormalities.

RESULTS

The mean age was 43.3 ± 8 years, and 888 CVD (4.3%) occurred. A single positive deflection of the P-wave (Pattern 1) was present in 29% for V1 and 81% for V2. A singular negative P-wave (Pattern 2) was present in 4.6% for V1 and 1.6% in V2. A P-wave with an upward component followed by downward component (Pattern 3) was present in 64.5% for V1 and 17.5% for V2. When the downward component in Patterns 2 and/or 3 is at least -100 μV, a significant association is observed with CVD (adjusted hazard ratios [HRs] 2.9-4.1, P < 0.001). Total P-wave duration ≥140 ms was also associated with CVD (adjusted HR 2.2, P < 0.001).

CONCLUSIONS

A negative P-wave in V1 or V2 ≤-100 μV, and P-wave with a duration of ≥140 ms, all have independent and significant associations with CVD, with HRs comparable to other electrocardiography abnormalities.