Electrocardiographic Parameter Research Articles

Deep terminal negative of the P wave in V1 and incidence of ischemic stroke: The atherosclerosis risk in communities (ARIC) study

BackgroundDeep terminal negative of the P wave in V1 (DTNPV1) is a marker of left atrial remodeling. We aimed to evaluate the association of DTNPV1 with incident ischemic stroke. MethodsThe Atherosclerosis Risk in Communities study is a prospective community-based cohort study. All participants at visit 4 (1996–1998) except those with prevalent stroke, missing covariates, and missing or uninterpretable ECG were included. DTNPV1 was defined as the absolute value of the depth of the terminal negative phase >100 μV in the presence of biphasic P wave in V1. Association between DTNPV1 as a time-dependent exposure variable and incident ischemic stroke was evaluated. The accuracy of the prediction model consisting of DTNPV1 and CHA2DS2-VASc variables in predicting ischemic stroke was analyzed. ResultsAmong 10,605 participants (63 ± 6 years, 56% women, 20% Black), 803 cases of ischemic stroke occurred over a median follow-up of 20.19 years. After adjusting for demographics, DTNPV1 was associated with an increased risk of stroke (HR 1.96, [95% CI 1.39–2.77]). After further adjusting for stroke risk factors, use of aspirin and anticoagulants, and time-dependent atrial fibrillation, DTNPV1 was associated with a 1.50-fold (95% CI 1.06–2.13) increased risk of stroke. When added to the CHA2DS2-VASc variables, DTNPV1 did not significantly improve stroke prediction as assessed by C-statistic. However, there was improvement in risk classification for participants who did not develop stroke. ConclusionDTNPV1 is significantly associated with higher risk of ischemic stroke. Since DTNPV1 is a simplified electrocardiographic parameter, it may help stroke prediction, a subject for further research.

New electrocardiographic parameters and risk of atrial arrhythmias in INOCA patients

Aims: Ischemia with no obstructive arteries (INOCA) is a clinical condition in which symptoms and signs of coronary artery disease are present, but coronary angiography does not show severe vessel narrowing. Atrial fibrillation (AF) is a common arrhythmia in cardiology practice, with an increasing prevalence with age and concomitant heart disease. P-wave dispersion (PWD) is an electrocardiographic (ECG) parameter defined as the difference between the maximum and minimum P-wave duration. There is an increasing number of studies showing an association between PWD and cardiovascular events. In this study, we aimed to evaluate the risk of AF in INOCA patients by detecting PWD, a new ECG parameter. Methods: The study included 51 INOCA patients and 36 healthy subjects as a control group. The groups were compared in terms of demographic characteristics, laboratory findings, echocardiography, and ECG findings. The difference between the longest P wave (Pmax) and the shortest P wave (Pmin) was considered as PWD (PWD=Pmax-Pmin). Results: When the patient group was compared with the control group, no difference was detected in terms of demographic characteristics or laboratory findings. When compared with the control group, Pmax duration and Pd values were significantly longer in the patient group compared to the control group (Pmax durations 112.7±7.09 ms and 98.1±5.5 ms, respectively, p<0.001; Pd durations 43.0±9.4 ms and 31.4±12.4 ms, respectively, p<0.001). On the other hand, Pmin durations did not differ significantly between the groups (p>0.05). Conclusion: We observed that PWD was higher in INOCA patients compared to controls, and our results suggest that INOCA patients are at risk for AF.

Evaluation of the risk of developing atrial fibrillation with new electrocardiographic parameters in patients with primary hyperparathyroidism

Aims: Primary hyperparathyroidism (PHPT) is a clinical entity characterized by hypercalcemia caused by excessive parathyroid hormone (PTH) secretion from the parathyroid gland and is the most common cause of hypercalcemia in outpatient clinics. Atrial fibrillation (AF) is a common arrhythmia encountered in cardiology practice, the prevalence of which increases with concomitant heart disease and age. P-wave peak time (PWPT) is the time from the onset of the p-wave to its peak and is a recently defined electrocardiographic (ECG) parameter. Recently, studies on the relationship between PWPT and cardiovascular events have been published. In this study, we aimed to evaluate the risk of AF in PHPT patients by detecting PWPT, a new ECG parameter.
 Methods: The study included 21 PHPT patients and 20 healthy subjects as a control group. The groups were compared in terms of demographic characteristics, laboratory findings, echocardiography, and ECG findings. D2 and V1 leads were used for PWPT, as recommended in the literature. 
 Results: When the patient group was compared with the control group, no difference was detected in terms of demographic characteristics and laboratory findings. When compared with the control group, patients with PHPT had significantly longer PWPT (PWPTV1 56.07 msec ± 8.33 s vs. 50.25 msec ± 7.00 s p

Decreased vector magnitudes may help identify events in patients with Long QT syndrome.

All Long QT syndrome (LQTS) patients are at elevated risk for channelopathy-induced delayed myocardial repolarization and consequently potentially life-threatening cardiac events with 90% of initial cardiac events occurring between preteen and 40years old. Utilizing ECG and derived vectorcardiographic parameters, including T wave Vector Magnitude (TwVM) measurement data, this study attempts to determine whether TwVM from baseline ECGs is effectively predictive of future cardiac events for genotype-positive LQTS patients. Verified carriers of established LQTS disease-causing genotypes were selected from University of Minnesota patient encounters between 2010 and 2020 for inclusion in this retrospective study. Baseline and predictive ECG and derived vectorcardiographic parameter evaluation, clinical data, and statistical analysis were compared between patients with and patients without cardiac events. First recorded ECG was at presentation to our hospital and final ECG is defined as ECG just prior to cardiac event (event defined below in Methods) or the most final documented ECG before cut-off year of 2020 for the event-free group. Of 41 participants, 15 experienced cardiac events and 26 did not. While many baseline electrocardiographic parameter measurements did not show significant differences between patient groups, vectorcardiographic parameters at baseline, specifically the QRS vector magnitude (QRSVM) and azimuth of the spatial ventricular gradient, showed significance. Additionally, final vectorcardiographic parameters, particularly the QRSVM, TwVM, and azimuth of the spatial ventricular gradient showed significant differences between patient groups. Final T-wave frontal axis was significantly larger in those without cardiac events. Significant Kaplan-Meier curve separation between patient groups was noted based on a QRSVM of 1.43mV or lower, with additional consideration to patient age, genotype, and beta blocker use. This study shows evidence of ECG and derived vectorcardiographic parameters, including TwVM, being effective in early prediction of cardiac events in genotype-positive LQTS patients.

Heart rate stability in a clinical setting and after a short exercise in healthy male volunteers.

Limited data exist on heart rate stabilization in the domiciled nature of phase I clinical studies, particularly when frequent measurements of QT intervals are involved. The present analysis aimed to evaluate heart rate stability in the domiciled nature of, and stabilization after a short exercise. Fifty-six healthy male subjects were included in this analysis. Data during a domiciled clinical setting and after a short exercise were analysed. Mean values of 30 s intervals of collected electrocardiographical data (PR, RR, QT and QTcF intervals) during a 10-min supine resting period in a domiciled nature or after walking up and down three stories (100 steps) were compared to baseline values using paired t-tests or compared to the intrasubject standard deviation. Stable heart rates and stable QTcF intervals observed immediately upon assuming a supine position in the domiciled clinical setting. After the short exercise, PR interval and RR interval were significantly (p < 0.05) shorter for up to 120 s (mean value -9.8 ± 7.2 ms) and 30 s (-160 ± 165 ms, p < 0.05), respectively. QT and QTcF intervals were significantly (p < 0.05) shorter for up to 90 and 120 s postexercise, respectively. Both QT and QTcF intervals stabilized after 2 min, but QT interval remained prolonged while QTcF interval returned to baseline levels. In a clinical setting, male volunteers do not require a waiting period for electrocardiographic parameter normalization. However, accurate measurement of these parameters following a short exercise necessitates a minimum 2-min resting interval.

Novel methods for enhancing ECG visualization research

All Long QT syndrome (LQTS) patients are at elevated risk for channelopathy-induced delayed myocardial repolarization and consequently potentially life-threatening cardiac events with 90% of initial cardiac events occurring between preteen and 40 years old. Utilizing ECG and derived vectorcardiographic parameters, including T wave Vector Magnitude (TwVM) measurement data, this study attempts to determine whether TwVM from baseline ECGs is effectively predictive of future cardiac events for genotype-positive LQTS patients.Verified carriers of established LQTS disease-causing genotypes were selected from University of Minnesota patient encounters between 2010 and 2020 for inclusion in this retrospective study. Baseline and predictive ECG and derived vectorcardiographic parameter evaluation, clinical data, and statistical analysis were compared between patients with and patients without cardiac events. First recorded ECG was at presentation to our hospital and final ECG is defined as ECG just prior to cardiac event (event defined below in Methods) or the most final documented ECG before cut-off year of 2020 for the event-free group.Of 41 participants, 15 experienced cardiac events and 26 did not. While many baseline electrocardiographic parameter measurements did not show significant differences between patient groups, vectorcardiographic parameters at baseline, specifically the QRS vector magnitude (QRSVM) and azimuth of the spatial ventricular gradient, showed significance. Additionally, final vectorcardiographic parameters, particularly the QRSVM, TwVM, and azimuth of the spatial ventricular gradient showed significant differences between patient groups. Final T-wave frontal axis was significantly larger in those without cardiac events. Significant Kaplan-Meier curve separation between patient groups was noted based on a QRSVM of 1.43 mV or lower, with additional consideration to patient age, genotype, and beta blocker use.This study shows evidence of ECG and derived vectorcardiographic parameters, including TwVM, being effective in early prediction of cardiac events in genotype-positive LQTS patients.

Coffee consumption and associations with blood pressure, LDL-cholesterol and echocardiographic measures in the general population

Coffee, next to water the most widespread beverage, is attributed both harmful and protective characteristics concerning cardiovascular health. This study aimed to evaluate associations of coffee consumption with cardiac biomarkers, echocardiographic, electrocardiographic parameters and major cardiovascular diseases. We performed a cross-sectional analysis of 9009 participants of the population-based Hamburg City Health Study (HCHS), enrolled between 2016 and 2018 median age 63 [IQR: 55; 69] years. Coffee consumption was classified into three groups: < 3 cups/day (low), 3–4 cups/day (moderate), > 4 cups/day (high). In linear regression analyses adjusted for age, sex, body mass index, diabetes, hypertension, smoking, and additives, high coffee consumption correlated with higher LDL-cholesterol (β = 5.92; 95% CI 2.95, 8.89; p < 0.001). Moderate and high coffee consumption correlated with lower systolic (β = − 1.91; 95% CI − 3.04, − 0.78; p = 0.001; high: β = − 3.06; 95% CI − 4.69, − 1.44; p < 0.001) and diastolic blood pressure (β = − 1.05; 95% CI − 1.67, − 0.43; p = 0.001; high: β = − 1.85; 95% CI − 2.74, − 0.96; p < 0.001). Different levels of coffee consumption did neither correlate with any investigated electrocardiographic or echocardiographic parameter nor with prevalent major cardiovascular diseases, including prior myocardial infarction and heart failure. In this cross-sectional analysis, high coffee consumption correlated with raised LDL-cholesterol levels and lower systolic and diastolic blood pressure. However, major cardiovascular diseases including heart failure and its diagnostic precursors were not associated with coffee consumption, connoting a neutral role of coffee in the context of cardiovascular health.

High risk of ventricular repolarization abnormalities among hemodialytic end-stage renal disease patients.

Patients with chronic renal disease (CKD) are at a significantly elevated risk for ventricular arrhythmia. Several electrocardiographic (ECG) methods can be used to assess the ventricular arrhythmia risk on the standard 12-lead ECG.

Coffee consumption and cardiovascular health in the general population

Abstract Background Coffee, next to water the most widespread beverage, is attributed both harmful and protective characteristics concerning cardiovascular health. This study aimed to evaluate associations of coffee consumption with cardiac biomarkers, echocardiographic, and electrocardiographic parameters as well as major cardiovascular diseases. Methods and results We performed a cross-sectional analysis of 9,009 participants a large German population-based cohort study, enrolled between 2016 and 2018 median age 63 [IQR: 55; 69] years. Coffee consumption was classified into three groups: &amp;lt;3 cups/day (low), 3–4 cups/day (moderate), &amp;gt;4 cups/day (high). In linear regression analyses adjusted for age, sex, body mass index, diabetes, hypertension, and smoking, moderate and high coffee consumption were associated with LDL-cholesterol (β=2.08; 95% CI: 0.14, 4.03, p=0.036; β=5.69; 95% CI: 2.91, 8.47; p&amp;lt;0.001). Moderate and high coffee consumption were negatively associated with systolic (β=−1.6; 95% CI: −2.66, −0.54; p=0.003; β=−2.63; 95% CI: −4.15, −1.12; p=0.001) and diastolic blood pressure (β=−0.8; 95% CI: −1.38, −0.22; p=0.007; β=1.28; 95% CI: −2.11, −0.45; p=0.002). Different levels of coffee consumption did neither correlate with any investigated electrocardiographic or echocardiographic parameter nor with prevalent major cardiovascular diseases, including prior myocardial infarction and heart failure. Conclusions In this cross-sectional analysis, moderate and high coffee consumption was positively associated with LDL-cholesterol and negatively associated with systolic and diastolic blood pressure. However, major cardiovascular diseases including heart failure and its diagnostic precursors were not associated with coffee consumption, connoting a neutral role of coffee in the context of cardiovascular health. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Deutsche Forschungsgemeinschaft [Grant Number TH1106/5-1; AA93/2-1]The Foundation Leducq [Grant Number 16 CVD 03]

Usefulness of P-wave peak time as an electrocardiographic parameter in predicting left ventricular diastolic dysfunction in patients with mitral regurgitation.

Conventional Doppler measurements have limitations in predicting left ventricular diastolic dysfunction (LVDD) in patients with mitral regurgitation (MR). Recently, electrocardiographic P-wave peak time (PWPT) has been proposed as a parameter of detecting LVDD. This study aimed to evaluate the association between PWPT and left ventricular end-diastolic pressure (LVEDP) in patients with MR. We performed echocardiography and cardiac catheterization in 82 patients with moderate or severe MR. We classified patients into two groups: low LVEDP group (L-LVEDP) (LVEDP <16 mmHg, n=40) and high LVEDP group (H-LVEDP) (LVEDP ≥16 mmHg, n=42). We evaluated LVDD and PWPT based on echocardiographic and electrocardiographic findings in both groups. The PWPT in lead II (PWPTII ) was significantly longer in patients in the H-LVEDP group than in those in the L-LVEDP group (67 vs. 47 ms, p < .001). Using correlation analysis, LVEDP was positively correlated with PWPTII (r=.577, p < .001). Using multivariate analysis, PWPTII was found to be an independent predictor of increased LVEDP (95% CI: 0.1030-0.110; p < .001). Using receiver operating characteristic (ROC) curve analysis, the optimal cutoff value of PWPTII for predicting elevated LVEDP was 58.9ms, with a sensitivity of 80.0% and a specificity of 73.8% (area under curve: 0.809, 95% CI: 0.713-0.905). To the best of our knowledge, this is the first study to assess the effect of a significant valvular disease on PWPT in lead II. These findings suggest that prolonged PWPTII may be an independent predictor of increased LVEDP in patients with moderate or severe MR.

R-WAVE PEAK TIME AS A NEW PREDICTOR OF MYOCARDIAL INJURY IN PATIENTS INFECTED WITH COVID-19

Objectives: Myocardial injury is closely associated with the poor prognosis of patients infected with coronavirus disease 2019 (COVID-19). Early diagnosis of cardiovascular complications that develop during the process of COVID-19 is crucial. R-wave peak time (RWPT) is an electrocardiographic parameter in which myocardial involvement caused by various situations is shown. This study was designed to assess the predictive value of RWPT in patients infected with COVID-19 who developed a myocardial injury. Methodology: A total of 138 patients diagnosed with COVID-19 were enrolled in this prospective study. The patients were classified according to their troponin values ─ study group (SG, n= 52) with high troponin and control group (CG, n= 86) without elevated troponin. All data obtained from patients were compared. Results: QRS duration (101 ± 5 ms vs. 99 ± 6 ms, p= .013) and RWPT (43 ± 6 ms vs. 38 ± 5 ms, p&lt;0.001) were significantly longer in SG than in the CG. In multivariate analysis, C-reactive protein (OR: 1.109, 95% CI: 1.058–1.163; p&lt;0.001), ejection fraction (OR: .844, 95% CI: .765–.931; p=0.001), and RWPT (OR: 1.211, 95% CI: 1.096–1.339; p&lt;0.001) were independent predictors of myocardial injury in COVID-19-infected individuals. The ROC analysis revealed a cut-off value of RWPT for myocardial injury of 40.5 ms, with a sensitivity of 63.5% and a specificity of 62.8% (AUC: 0.730, 95% CI: 0.641–0.819, p&lt;0.001). Conclusion: RWPT is a significant predictor of myocardial injury and may benefit in better identifying patients with myocardial injury in COVID-19.

QTc Interval is Associated with Atrial Fibrillation in Individuals with Metabolic Syndrome Phenotype.

PurposeManifestations of metabolic syndrome (MetS) carry risks for atrial fibrillation (AF). The study determined whether any electrocardiographic parameter can reflect increased AF risk in individuals with MetS.Patients and MethodsFrom our University Hospital database, we examined the presence of AF and its correlation with MetS manifestations, renal function, lipid profiles, and electrocardiographic parameters (P wave duration, PR interval, QRS width, and QTc intervals). Between January 2008 and December 2015, data from 4479 adults (women 41.6% vs men 58.4%) were identified.ResultsThe overall prevalence of AF was 12.4%, without sex differences (women, 12.8% vs men, 12.1%). Patients with AF were older (age 73.9 ± 11.8 vs non-AF 67 ± 13.5 years), with lower lipid levels (TG, total cholesterol, and LDL-cholesterol, all p < 0.0001), and at lower eGFR level (64.1 ± 30.9 vs non-AF 68.8 ± 41.4 mL/min/1.73m2, p < 0.0001). Besides, sex differences were present in all electrocardiographic parameters (all p < 0.05). Hypertension had the highest odds ratio (1.33; p = 0.026) for AF. Comparing AF to non-AF, the QTc of quartiles was significantly different (p < 0.0089). The shortest and longest QTc quartiles had an increased incidence of AF.ConclusionAF risk in patients with MetS phenotypes can be reflected by QTc quartiles.

General anesthesia and electrocardiographic parameters in in vivo experiments involving rats.

In in vivo cardiovascular or toxicological studies involving rat models, changes in selected electrocardiographic (ECG) parameters are monitored after various interventions to assess the origin and development of heart rhythm disorders. Each ECG parameter has diagnostic significance; as such, commonly evaluated ECG parameters, including heart rate, PR interval, P wave duration, P wave amplitude, QRS complex, QT and QTc interval duration, R wave and T wave amplitude, of rats under various types of general anesthesia were the focus of this study. Studies that performed in vivo cardiovascular or toxicological experiments in rats were retrieved from a search of the Web of Science database for articles published mainly between 2000 and 2021. In total, the search retrieved 123 articles. ECG parameters that were reported as baseline or control values were summarized and averages with ranges were calculated. It is important to be cautious when interpreting results and, in discussions addressing the mechanisms underlying a given type of arrhythmia, acknowledge that initial ECG parameters may already be affected to some extent by the general anesthesia as well as by sex and the time of day the experiments were performed.

A novel electrocardiographic parameter for the prediction of atrial fibrillation after coronary artery bypass graft surgery "P wave peak time".

Patients with postoperative atrial fibrillation (POAF) have increased risk of both short- and long-term mortality and morbidity; therefore, prediction of POAF is crucial in the preoperative period of the patients undergoing coronary artery bypass graft surgery. Electrocardiography (ECG) is the simplest and cost-effective tool in the preoperative workup of the patients for the prediction of POAF. A newly defined ECG parameter P wave peak time (PWPT) has been shown as a marker of atrial fibrillation development in non-surgical patients and we investigated its role in patients undergoing cardiac surgery. A total of 327 patients undergoing isolated or combined cardiac surgery were involved and the primary endpoint was defined as the development of POAF. The study population was divided into two groups based on the presence or absence of POAF. Groups were compared for both standard P wave parameters and for PWPT on surface ECG. The predictors of POAF were assessed by multivariate regression analysis. The frequency of POAF was 20.4% (n = 67). P wave peak time in leads D2 (65.1 ± 11.8 vs 57.2 ± 10, p < 0.01) and V1 (57.8 ± 18 vs 44.8 ± 12.3, p < 0.01) were longer in patients with POAF. In multivariate regression analysis, PWPT in leads DII and V1 were independent predictors of POAF (OR: 1.11, 95%CI: 1.02-1.21, p = 0.01, OR: 1.06, 95%CI: 1.00-1.13, p = 0.03 respectively). PWPT in leads DII and V1 can predict the development of POAF in patients undergoing cardiac surgery.

ACUTE EFFECTS OF SMOKING ON VENTRICULAR REPOLARIZATION

Objective: Cigarette smoking, modifiable and preventable risk factor of death due to cardiovascular changes globally. As the frequency increases, this alters the ventricular repolarization and sympathetic tone lead to ventricular arrhythmogenesis. The aim and objective of the study are to evaluate the effects of smoking (before and immediately after smoking) on ventricular repolarization by recording the Tp-e interval, Tp-e/QTc ratio by using an electrocardiogram, since it is an accurate, less expensive, and non – invasive tool. Methods: Around 40 healthy male volunteers who are smokers aged between 18 and 25 years were recruited in this study. All subjects were non-alcoholics, non–tobacco chewers took no drugs, and had a uniform pattern of diet and activity. The acute effect of smoking on the heart was determined by measuring the electrocardiographic parameter before and immediately after smoking a king-size cigarette. Results: The analysis showed that there was a statistically significant increase in heart rate immediately after smoking compared to baseline values in smokers. TP interval and Tp-e interval were increased immediately after smoking and were highly significant. Conclusion: Our study has proven that there was a remarkable change in cardiac activity immediately after smoking. Tp-e Interval may serve as a better risk factor to predict sudden cardiac arrest in the future especially in chronic smokers. Smoker’s heart is already injured due to its injurious chemicals, adding on to that every new cigarette increases the burden on cardiovascular health. Hence, it is never late to quit smoking rather than suffering from its injurious effect.

Evaluation of electrocardiographic changes in patients under COVID-19 treatment regimes

Background and Aim: Awareness of electrocardiographic (ECG) changes is crucial in patients who receive coronavirus disease 2019 (COVID-19) treatment. In this study, we aimed to evaluate ECG parameters in patients under COVID-19 therapy and their relationship with the severity of lung involvement and the disease on the basis of thoracic computerized tomography (TCT) findings and laboratory parameters. Materials and Methods: Of 350 patients hospitalized due to COVID-19 between March 2020 and June 2020, 300 patients with available data were retrospectively analyzed. Blood analysis, electrocardiographic, and clinical findings were evaluated. Six-month follow-up data were also recorded. Results: The patients were categorized into two groups: survivor (n = 206, 68.7%, Group 1) and nonsurvivor patients (n = 94, 31.3%, Group 2). The mean total follow-up period was 125.39 ± 73.09 days. The mean age was similar in both groups. In multivariate regression analysis that aimed to predict COVID-19 disease severity, it was found that besides increased C-reactive protein and D-dimer levels, and ≥50% lung involvement in TCT, which are well known as bad prognostic factors, the corrected QT interval duration (QTc) prolongation ≥60 miliseconds (msn) during hospitalization was associated with worse prognosis in COVID-19 patients during follow-up. Conclusion: Our study is the first study that demonstrated that the presence of ≥60 msn QTc prolongation during hospital stay was found to be the most valuable ECG parameter to predict the prognosis and had a significant association with ≥50% lung involvement in TCT in patients under anti-COVID therapy. Close monitoring of this ECG parameter is important both in terms of treatment planning and interpretation of disease progression.

Tip 1 Diabetes Mellitusta Kardiyak Elektrofizyolojik Denge İndeksinin Değerlendirilmesi

Background: Type 1 diabetes mellitus (T1DM) has been suggested to carry the risk of developing cardiac arrhythmias. The risk of cardiovascular events and sudden death is higher in patients with T1DM. The index of cardiac electrophysiological balance (iCEB), which shows the balance between ventricular depolarization and repolarization, is a new electrocardiographic (ECG) parameter when compared to other ECG parameters. iCEB provides more information on ventricular arrhythmo-genesis than the other traditional ECG parameters such as QT and corrected QT (QTc) intervals. The aim of this study is to evaluate the relationship between T1DM and iCEB.Materials and Methods: This study was conducted retrospectively. The patient group consisted of 50 patients (58% male, mean age 32.9 ± 8.7 years) diagnosed with T1DM, while the control group consisted of 50 healthy individuals (58% male, mean age 33.9 ± 6.8 years). The clinical, demo-graphic and ECG records of the patients were obtained from our hospital's medical documentation system. iCEB and corrected iCEB (iCEBc) values of all participants were calculated by dividing the relevant QT and QTc intervals by the QRS duration.Results: Mean PR, QRS, and QT intervals were similar between groups, while mean heart rate and QTc interval were found to be higher in the T1DM group than in healthy subjects [(83.1 ± 9.8 vs 78.9 ± 13.3 bpm, respectively, p = 0.019) and (425 ± 20.4 vs 397.6 ± 10.6 ms, respectively, p &amp;lt; 0.001)]. The iCEBc of the patient group with T1DM was higher than the control group (5.1 ± 0.5 vs 4.7 ± 0.4 ms, p &amp;lt;0.001, respectively). However, there was no significant difference in iCEB be-tween the patient and control groups (4.3 ± 0.4 and 4.3 ± 0.4 ms, respectively, p = 0.402).Conclusions: In our study, iCEBc was found to be significantly increased in T1DM patients com-pared to healthy subjects. Consequently; it is important to evaluate the risk of ventricular ar-rhythmia with iCEBc in T1DM patients.Key Words: Electrocardiography, Index of cardiac electrophysiological balance, Type 1 diabetes mellitus, Ventricular arrhythmia

Central Sleep Apnea Is Associated with an Abnormal P-Wave Terminal Force in Lead V1 in Patients with Acute Myocardial Infarction Independent from Ventricular Function.

Sleep-disordered breathing (SDB) is highly prevalent in patients with cardiovascular disease. We have recently shown that an elevation of the electrocardiographic (ECG) parameter P wave terminal force in lead V1 (PTFV1) is linked to atrial proarrhythmic activity by stimulation of reactive oxygen species (ROS)-dependent pathways. Since SDB leads to increased ROS generation, we aimed to investigate the relationship between SDB-related hypoxia and PTFV1 in patients with first-time acute myocardial infarction (AMI). We examined 56 patients with first-time AMI. PTFV1 was analyzed in 12-lead ECGs and defined as abnormal when ≥4000 µV*ms. Polysomnography (PSG) to assess SDB was performed within 3–5 days after AMI. SDB was defined by an apnea-hypopnea-index (AHI) >15/h. The multivariable regression analysis showed a significant association between SDB-related hypoxia and the magnitude of PTFV1 independent from other relevant clinical co-factors. Interestingly, this association was mainly driven by central but not obstructive apnea events. Additionally, abnormal PTFV1 was associated with SDB severity (as measured by AHI, B 21.495; CI [10.872 to 32.118]; p < 0.001), suggesting that ECG may help identify patients suitable for SDB screening. Hypoxia as a consequence of central sleep apnea may result in atrial electrical remodeling measured by abnormal PTFV1 in patients with first-time AMI independent of ventricular function. The PTFV1 may be used as a clinical marker for increased SDB risk in cardiovascular patients.

Delta QRS distinguishes Ito -mediated J waves from pseudo J waves produced by conduction delay on body surface electrocardiographic.

On surface electrocardiographic (ECGs), it is difficult to differentiate Ito -mediated J waves, a repolarization phenomenon seen in J wave syndromes (JWS) from terminal QRS deflections that mimic J waves (pseudo J waves) in intraventricular conduction delay (IVCD), an abnormality in depolarization. We hypothesize that the difference between the "maximum QRS duration" inclusive of J point or terminal QRS deflections and the minimum QRS duration identified across a 12-lead ECG is significantly larger in Ito -mediated J waves, and can serve as a marker to make this distinction. A retrospective analysis was performed on adults with ECGs consisting of one of the four following manifestations: J waves associated with hypothermia and early repolarization, and pseudo J waves associated with right bundle branch block (RBBB) and non-specific intraventricular conduction delay (NS-IVCD). All ECGs were assessed individually and the maximum and minimum discrete QRS deflections on 12-lead tracings, defined as "QRSmax " and QRSmin , were identified. The difference between "QRSmax " and QRSmin , designated as ∆QRS, was calculated and compared across the studied populations. A total of 60 patients consisting of 15 patients in each arm were included in the study. ΔQRS was significantly larger in the hypothermia and early repolarization groups, compared to RBBB and NS-IVCD (p<.0001), with the following mean ∆QRS: hypothermia 54.3±13.7ms, early repolarization pattern 47.3±15.3ms, RBBB 19.3±6.5ms, and NS-IVCD 16.0±6.6ms. ∆QRS may serve as a reliable ECG parameter for distinguishing Ito -mediated J waves from pseudo J waves produced by delayed intraventricular conduction.

Exploration of electrocardiographic and echocardiographic findings to screen transthyretin amyloid cardiomyopathy in patients with mild left ventricular hypertrophy

Abstract Background The transthyretin amyloid cardiomyopathy (ATTR-CM), a common condition in the elderly, is a life-threatening disease; however, it is treatable. The early accurate diagnosis is, therefore, an important key to improve the patient's outcomes. Electrocardiography and echocardiography are instant diagnostic tools with red flags for the screening of the ATTR-CM. In fact, ATTR-CM often mimics left ventricular hypertrophy (LVH), and the differential diagnosis is difficult to establish. Thus, the characteristics of cardiac amyloidosis may be obscured in ATTR-CM patients with mild LVH, possibly making the disease difficult to diagnose. Therefore, in this study, the effect of LVH on the occurrence of electrocardiographic and echocardiographic parameters for ATTR-CM was investigated, and their incremental value over the age for the screening of ATTR-CM in the patients with mild LVH was recorded. Methods This study retrospectively studied 319 consecutive nonischemic LVH patients with a sinus rhythm who underwent detailed diagnostic tests. The light chain-associated amyloidosis was an exclusion criterion. The mean left ventricular wall thickness (MWT) &amp;lt;12 mm was defined as mild LVH, while MWT ≥12 mm was defined as moderate to severe LVH. The ATTR-CM was diagnosed with biopsy or 99 mTc-PYP scintigraphy. The elderly were defined as people aged ≥65 years in males and ≥70 years in females, according to the literature. Each electrocardiographic and echocardiographic parameter was binarized with an external cut-off point to increase the external validity, being the incremental benefit of each parameter over age for identifying ATTR-CM assessed using a receiver operating characteristic curve analysis and comparisons of the area under the curve (AUC). Results Fourteen patients (8%) among the 170 patients with mild LVH had ATTR-CM, while 27 patients (18%) among the 149 patients with moderate to severe LVH had ATTR-CM. The patients with mild LVH had fewer electrocardiographic and echocardiographic parameters, showing a significant difference between ATTR-CM and non-ATTR-CM patients than those with moderate to severe LVH (Table 1). Among several binarized parameters, the voltage-to-mass ratio, E/A ratio, the global longitudinal strain, and also the relative apical sparing pattern demonstrated additive value for identifying the ATTR-CM over aging (Table 2). In addition, the discriminative ability of the propensity score calculated from these four variables and age was considered excellent for the screening of ATTR-CM (AUC = 0.98). Conclusion The patients with mild LVH appear to have fewer electrocardiographic and echocardiographic specific findings of the ATTR-CM compared to patients with moderate to severe LVH. However, several red flags may be useful for screening ATTR-CM even in patients with a mild LVH. Funding Acknowledgement Type of funding sources: None. Table 1Table 2