Early Repolarization Research Articles

Effects of Early Repolarization on Electrocardiography and Long-Term Cardiovascular Outcomes: A 15-Year Population-Based Cohort Study.

We aimed to investigate the association between persistent early repolarization (ER) in healthy individuals and long-term cardiovascular events and mortality rates in a large cohort study. Demographic characteristics, medical records, 12-lead electrocardiograms (ECGs), and laboratory data were retrieved and analyzed from the Isfahan Cohort Study. The participants were followed up biannually via telephone interviews and 1 live structured interview in between until 2017. Individuals who had ER in all their ECGs were considered persistent ER cases. Study outcomes were cardiovascular events (unstable angina, myocardial infarction, stroke, and sudden cardiac death), cardiovascular-related mortality, and all-cause mortality. The independent t test, the χ2 test, the Mann-Whitney U test, and the Cox regression models were used for statistical analyses. The study population consisted of 2696 subjects (50.5% female). Persistent ER was found in 203 subjects (7.5%), with a higher frequency in men (6.7% vs 0.8%; P<0.001). Cardiovascular events, cardiovascular-related mortality, and all-cause mortality occurred in 478 (17.7%), 101 (3.7%), and 241 (8.9%) individuals, respectively. After controlling for known cardiovascular risk factors, we found an association between ER and cardiovascular events (adjusted hazard ratio [95% confidence interval] =2.36 [1.19-4.68], P=0.014), cardiovascular-related mortality (4.97 [1.95-12.60], P=0.001), and all-cause mortality (2.50 [1.11-5.58], P=0.022) in women. No significant association was found between ER and any study outcomes in men. ER is common in young men with no apparent long-term cardiovascular risks. In women, ER is relatively rare, but it could be associated with long-term cardiovascular risks.

The year in cardiovascular medicine 2022: the top 10 papers in arrhythmias.

(A) Comprehensive clinical, electrocardiographic, and genetic overview of the various diseases associated with VA or SCD as reported in the 2022 ESC Guidelines for VA and SCD.1 The VA/SCD Guidelines provide many updated recommendations for the management of patients with congenital heart disease, idiopathic VF, acquired Long QT, Brugada and early repolarization syndrome, as well as catecholaminergic polymorphic VT, and short QT syndrome. (B) From the same Guidelines, an algorithm for the management of sustained monomorphic ventricular tachycardia in patients with chronic coronary artery disease.1 The algorithm also holdsin partfor non-ischaemic pathologies. Note, the new VA/SCD Guidelines promote VT ablation significantly. It may e.g. be performed to ameliorate or avoid ICD therapy, or to enhance resynchronization therapy by ablation of frequent monomorphic PVCs (extrasystolopathy). The trials PARTITA, PAUSE-SCD, and SURVIVE-VT, discussed in the present paper, all strengthen the recommendations for application of catheter ablation.57 (C) Exercise causes downregulation of genes coding intercalated disk proteins, as well as scaffolding and ion channel proteins, both in normal mice and PKP2 conditional knockouts. Consistent with PKP2-dependent muscle mass deficit, cardiac dimensions in human athletes carrying PKP2 mutations were reduced (data not shown), compared with matched controls. Exercise challenges a cardiomyocyte desmosomal reserve which, if impaired genetically (e.g. Plakophilin2 loss), can cause accelerated progression of the cardiomyopathy.3 Reprinted with permission.

НАРУШЕНИЯ РИТМА И ПРОВОДИМОСТИ У ПАЦИЕНТОВ С ЭЛЕКТРОКАРДИОГРАФИЧЕСКИМ ФЕНОМЕНОМ РАННЕЙ РЕПОЛЯРИЗАЦИИ ЖЕЛУДОЧКОВ

The frequency and nature of cardiac arrhythmias and conduction disturbances in children and adolescents with electrocardiographic syndrome of early ventricular repolarization were studied. It has been determined that cardiac rhythm and conduction disturbances in patients with early ventricular repolarization syndrome are quite common, with a predominance of arrhythmias caused by a change in the automatism function of the sinus node and the presence of intraventricular blockades. It was revealed that in children with this electrocardiographic phenomenon, in the vast majority of cases, there are manifestations of the syndrome of connective tissue dysplasia - minor anomalies in the development of the heart – 84.1%, (p &lt; 0.001), and additional chords are most often recorded in the cavity of the left ventricle – 85.6% (p &lt; 0.001), both isolated and in combination with other anomalies and congenital heart defects. It was found that cardiac rhythm and conduction disturbances in patients with electrocardiographic syndrome of early ventricular repolarization are quite common (78.6±1.84%), with a predominance of cases of arrhythmias caused by changes in the automatism function of the sinus node (p &lt; 0.001) and the presence of intraventricular blocks. In children and adolescents with early ventricular repolarization, additional chords are most often recorded (85.6%, (p &lt; 0.001)), both isolated and in combination with other heart anomalies. The data obtained indicate the presence of a relationship between the early ventricular repolarization syndrome and connective tissue dysplasia, which makes it possible to attribute this electrocardiographic syndrome to the conditions associated with this syndrome.

ST domed Elevation – an Atypical Variant of Early Repolarization in the White Athlete after the COVID-19 Pandemic. A Case Report.

Background: Interpreting the electrocardiography (ECG) recording in young athletes is challenging for the sports doctor. Changes in intraventricular conduction and early ventricular repolarization observed during sports training are not always confirmed in the literature. We test healthy people and look for irregularities in their ECG records. The study aims to draw attention to ST-Elevation (STE) as a variant of the White Athlete's heart norm, with a frequency lower than an inverted T wave (TWI), but also as an effect of early repolarization of the ventricles in young athletes. Is it physiology? Case report: 14-year-old football player, examined for five years at a sports clinic, cardiology checked every year. Changes like symptomatic adult ECGs with STE and myocardial necrosis were suspected during our observation. Echocardiography, stress test good. A simple response to exercise is to adapt the athlete's heart by ischemia, preconditioning for the heart muscle, and a reversible remodelling that disappears after the sports period. We focus on changes in ECG, which are observed in athletes under 14 years of age, while most of the ECG classifications in an athlete were described above 16 years of age. Conclusion: the variant observed in our White Athlete is an example of several similar repolarization changes in ECG not yet classified as physiological or resulting from intensive training.

Cardiac Morphofunctional Characteristics of Individuals with Early Repolarization Pattern: A Literature Review

The early repolarization pattern (ERP) is an electrocardiographic phenomenon characterized by the appearance of a distinct J-wave or J-point elevation at the terminal part of the QRS complex. ERP is associated with an increased risk of ventricular arrhythmias in susceptible individuals. The cardiac morphofunctional parameters in subjects with ERP have been characterized mainly by imaging techniques, which suggests that certain changes could be identified in the background of the electrical pathomechanism: however, in this regard, current data are often contradictory or insufficiently detailed. For clarification, a more comprehensive cardiac imaging evaluation of a large patient population is necessary. This review summarizes and analyses the data from the literature related to cardiac morphofunctional characteristics in individuals with ERP.

Automated evaluation of ECG parameters during the COVID-19 pandemic

Algorithms for prompt automated evaluation of electrocardiogram parameters in the absence of specialized equipment and specialized specialists are considered. The patient’s electrocardiogram is recorded on a paper tape, then it is photographed on the primary care doctor’s mobile phone and processed by a specialized application. The application digitizes the photographed image of the electrocardiogram, evaluates its main parameters as well as calculates criteria for the differential diagnosis of certain diseases using approximate formulas. In addition, the digitized electrocardiogram image is transmitted to the server and processed using a machine learning system. Algorithms for digitizing and analyzing an electrocardiogram have been developed that make it possible to evaluate its elements that are important for diagnosis, and the average error in determining the position of the most complex (smoothed) peaks — P and T waves — was no more than 0.1 mm. An algorithm for the criteria analysis of an electrocardiogram is proposed to support the differential diagnosis of acute myocardial infarction with ST segment elevation and early ventricular repolarization syndrome which provides accuracy values of 0.85 and F-scores of 0.74. An alternative algorithm based on a deep neural network is proposed which provides the best values — 0.96 and 0.88, respectively, but requires large computing resources and is executed on the server. The algorithms are implemented as a set of library functions. They can be used both independently and as part of a full-scale clinical decision support system for automated evaluation of electrocardiogram parameters based on a client-server architecture. In addition, all calculation results, together with a photograph of the original electrocardiogram, can be promptly transferred to a qualified cardiologist in order to receive an advisory opinion remotely.

The Utility of Sodium Channel Provocation in Unexplained Cardiac Arrest Survivors and Electrocardiographic Predictors of Ventricular Fibrillation Recurrence.

The implications of a drug-induced type 1 Brugada ECG pattern following sodium channel blocker provocation (SCBP) are not fully understood. Baseline clinical and ECG data were obtained from consecutive unexplained cardiac arrest survivors undergoing SCBP at 3 centers. A further 15 SCBP positive (SCBP+) unexplained cardiac arrest survivors were recruited from 3 additional centers to explore ventricular fibrillation recurrence. A total of 121 consecutive unexplained cardiac arrest survivors underwent SCBP. The yield of the drug-induced type 1 Brugada ECG pattern was 17%. A baseline type 2/3 Brugada pattern (T2/3BP) (adjusted odds ratio, 19.36 [2.74-136.61]; P=0.003) and PR interval (odds ratio, 1.03 [1.01-1.05] per ms; P=0.017) were independent predictors of SCBP+ response. A pathogenic SCN5A variant was identified in 36% of the SCBP+ group versus 0% in the SCBP- group (P<0.001). Amongst SCBP+ patients, a spontaneous type 1 Brugada pattern was identified in 19% during follow up and in 24% a type 1 Brugada pattern was identified in a relative. Prior syncope (adjusted hazard ratio, 3.83 [1.36-10.78]; P=0.011) and the presence of global early repolarization (hazard ratio, 7.91 [3.22-19.44]; P<0.001) were independent predictors of 5-year ventricular fibrillation recurrence. There was a nonsignificant trend toward greater 5-year ventricular fibrillation recurrence in the SCBP- group (23/95 [24%] versus 3/34 [9%]; P=0.055). The yield of the drug-induced type 1 Brugada ECG pattern in consecutive unexplained cardiac arrest survivors undergoing SCBP is 17%. A baseline T2/3BP and PR interval were independent predictors of the drug-induced type 1 Brugada ECG pattern. Greater heritability of BrS phenotype in this group was evidenced by a greater prevalence of pathogenic SCN5A variants and relatives with a type 1 Brugada pattern. A history of prior syncope and the presence of global early repolarization were independent predictors of ventricular fibrillation recurrence.

Risk stratification of ventricular fibrillation in patients with symptomatic Brugada syndrome using pharmacological tests.

Brugada syndrome (BrS), which is characterized by J-point elevation in right precordial leads of a 12-lead electrocardiogram, is associated with the occurrence of ventricular fibrillation (VF). However, risk stratification of VF in patients with BrS remains challenging. The aim of this study was to identify a risk predictor of VF in patients with BrS using pharmacological tests. Twenty-one consecutive patients with BrS and a history of documented spontaneous VF (n = 16) or syncope presumed to be caused by lethal ventricular arrhythmia (n = 5) were enrolled. J-wave changes in response to intravenous verapamil, propranolol, and pilsicainide were separately assessed. During the median follow-up period of 86.0 months, 8 patients had VF recurrence (recurrence group) and 13 patients did not have VF recurrence (non-recurrence group). Intravenous propranolol injection induced significant J-wave augmentation (i.e., increase in amplitude >0.1 mV) in the inferior and/or lateral leads in the recurrence group compared to the non-recurrence group (p = .048 and p = .015, respectively). Kaplan-Meier analysis revealed that VF recurrence is significantly higher in patients with BrS and J-wave augmentation due to intravenous propranolol than in patients without J-wave augmentation (p = .014). The study results show that propranolol-induced J-wave augmentation is involved in the risk of VF in patients with BrS. The results suggest that early repolarization patterns in response to pharmacological tests may be useful for risk stratification of VF in patients with symptomatic BrS.

Outcome of patients with idiopathic ventricular fibrillation and correlation with ECG markers of early repolarization

BackgroundEarly repolarization pattern (ERP) has been associated with idiopathic ventricular fibrillation (IVF) and with cardiovascular mortality in the general population. As there is limited data about long- term outcome of IVF, the aim of our study was to observe ventricular arrhythmia (VA) recurrences in these patients and to identify a possible correlation of VA with ECG markers of early repolarization.Methods and resultsWe investigated 56 consecutive IVF patients who received an implantable cardioverter-defibrillator for secondary prevention. ERP was defined as a J-point elevation ≥ 0.1 mV in two or more contiguous inferior or lateral leads. Markers of early repolarization were present in 32.1% of cases with a preponderance of QRS slurring (77.8%). During a mean follow-up of 41.2 months, 11 patients (19.6%) received in total 18 adequate ICD-therapies. VF was most the common cause for ICDtherapy (61.1%) but monomorphic VT also occurred in four patients. Presence of ERP was associated with a significant trend towards arrhythmia recurrences. 38.9% patients with ERP received appropriate ICD-therapies whereas only 10.5% of patients without ERP had arrhythmia recurrence (p = 0.05). Inappropriate ICD-therapies occurred in seven patients (12.5%) with a non-significant trend towards a higher incidence in patients with a transvenous ICD (p = 0.15).ConclusionA significant correlation between ERP and VA recurrences in patients with IVF could be observed. Though monomorphic VA also play a role in the studied IVF-population, our data support the use of the S-ICD in this collective.Graphical abstract

Abstract 13011: A Rare Case of Spontaneous Coronary Artery Dissection

Introduction: Spontaneous coronary artery dissection (SCAD) is a rare condition; an intimal tear or bleeding of vasa vasorum leads to the creation of a false lumen filled with intramural hematoma. The hematoma causes coronary stenosis, leading to subsequent myocardial ischemia. SCAD is the cause of Acute Coronary Syndrome (ACS) in 0.1 to 4% of cases. Men account for less than 10% of cases, with a mean age of 48.6. Case Study: A 19-year-old male with prior medical history of morbid obesity and marijuana use was transferred from another hospital to our service after presenting with non-ST elevation MI. He was admitted following 30 minutes of a throbbing/pressure-like sensation in his throat, one episode of vomiting, and paresthesia in his left arm that spontaneously resolved. Initial EKG showed sinus rhythm with early repolarization changes. His troponin rose from 0.2 to 18 ng/mL. Upon admission, his high sensitivity troponin peaked at 15,000 pg/mL. Repeat EKG showed dynamic changes with T wave inversions in the inferolateral leads. The patient underwent an angiogram showing a diffuse, mid-LAD 40% de novo spontaneous dissection and a diffuse, distal-LAD 20% de novo spontaneous dissection with TIMI grade 3 and 2 flow, respectively. A repeat angiogram two days later showed improved coronary artery flow and deemed a low-risk lesion with stable patient hemodynamics; no intervention followed. The patient was treated conservatively with DAPT and discharged home with an outpatient Cardiology follow-up. A plan to have further imaging in 4 weeks to assess hematoma resolution was made. Conclusions: This case demonstrates an atypical presentation of SCAD in a very low-risk patient, given his sex, age, and clinical presentation of nonspecific chest pain. This case highlights the importance of high clinical suspicion for SCAD regardless of ACS risk profile in a patient presenting with chest pain.

Abstract 11779: Impinged RCA: Who's the Culprit?

Introduction: Post-sternotomy chest pain (CP) has been widely reported in literature. The etiologies include myocardial infarction, pulmonary embolism, hypersensitivity reactions to foreign material, wound infection, sternal instability and dehiscence, neuropathic pain due to intercoastal nerve damage or sternal wire fracture leading to migration. Here, we report a rare case of a young patient who presented with chronic chest pain after an atrial septal defect (ASD) repair. Case: A 28-year-old male with past medical history significant for an ASD (secundum) repair with autologous pericardial patch, hyperlipidemia, COVID-19 infection, known first degree AV block, and early repolarization changes, presented for a follow-up office visit three years after his ASD repair with complaints of typical anginal symptoms. Diagnosis: Vitals, physical exam, troponin, D-dimer and inflammatory markers were unremarkable. Chest x-ray (Figure 1A) showed sternal wires in place and no fractures of wires. EKG (Figure 1B) was unchanged. Echocardiogram showed LVEF 50% and no wall motion abnormalities. He underwent a coronary CTA which identified intermittent compression on the mid-RCA from the third bottom stainless steel sternal wire (Figure 1C), warranting removal. Treatment: He underwent explantation of all sternal wires and selective right coronary angiography (Figure 1D) was performed, which revealed intact and patent RCA without any complications. He continues to follow-up in our clinic without any CP. Conclusions: Chronic CP after any cardiac surgery remains a diagnostic dilemma and a source of anxiety for patients. We recommend comprehensive discussions with patients prior to surgery about these probable complications to alleviate the anxiety. Lastly, from research thus far, removal of sternal wires is a safe, simple, and effective procedure that should be offered to patients with persistent post-sternotomy CP after exclusion of serious complications.

Abstract 10184: The Risk Factors for Ischemic Sudden Cardiac Death in Women

Background: Sudden cardiac death (SCD) is a significant cause of death accounting for 15-20 % of all deaths in Western countries. Coronary artery disease (CAD) is the most common cause of SCD. Even though women are at a lower risk for SCD &amp; CAD, the decline in mortality of these conditions has been slower in women than in men. Previous studies have shown that CAD is more challenging to detect in women, hence SCD is often the first manifestation of underlying CAD among women. The aim of this case-control study was to determine factors associated to SCD due to CAD in women. Methods: The study group consists of women with ischemic SCD (N=888) derived from the Fingesture study conducted in Northern Finland from 1998 to 2017 and all SCDs were autopsy verified. The control group consisted of women with angiographically verified CAD without SCD occurring during the 5-year-follow-up (N=610) from Artemis study. To perform comparison between these groups, we utilized medical records, autopsy findings, echocardiograms and ECGs. Results: Subjects with SCD were older (73.2±11.3 vs. 68.8±8.0 p &lt; 0.001) and were more likely to be smokers or ex-smokers (37.1% vs. 27.6 %, p = 0.045). The proportion of subjects with prior myocardial infarction (MI) was higher in controls (46.9 % vs. 41.4 % in SCD subjects, p = 0.037), but in contrast, SCD subjects were more likely to have underlying silent MI (25.6 % vs. 2.4 % in CAD controls, p &lt; 0.001). Decreased left ventricular ejection fraction (LVEF 35-55 %) was more common finding in SCD subjects than in CAD controls (33.1% vs. 8.7 %, p &lt; 0.001, respectively) as well as LV hypertrophy (70.9 % vs. 55.1 %, p &lt; 0.001, respectively). Various ECG-abnormalities were more common in SCD subjects including higher heart rate, prolonged QTc- and JTc-intervals, wide or fragmented QRS-complex, short PR-interval and early repolarization. The prevalence of Q-waves and T-inversions did not differ between these groups. Conclusions: Underlying CAD and MI are often underdiagnosed in women with ischemic SCD considering the high proportion of silent myocardial infarctions and the number of subjects without prior CAD diagnosis. LV hypertrophy as well as decreased LVEF were more frequent findings in SCD subjects. Several ECG abnormalities were more common among subjects with SCD.

Abstract 14679: Electrocardiogram Findings From Athletic Adaptation and COVID-19 Infection in Collegiate Football Players

Introduction: Improved criteria have enhanced the sensitivity and specificity of the 12-lead ECG to identify underlying cardiovascular conditions predisposing to sudden cardiac death or morbidity. However, the impacts of chronic high-intensity exercise and especially ethnicity on changes in longitudinal ECG remain unknown. Furthermore, given the ongoing pandemic, we must consider how COVID19 infection may impact ECG findings. We analyzed collegiate student athlete ECGs over time to determine whether longitudinal training, race, and post-COVID19 status impact the ECG findings with the goal of informing future interpretation criteria. Methods: We included twenty-two NCAA Division I football players from January 2018 to January 2021. Ten athletes contracted COVID19 during this period. We compared pre-season ECGs prior to the first and third years of athletic participation as well as any within 34 days after confirmed COVID19 infection. Heart rate, QRS duration, QT interval, and any International Criteria findings were identified. The ECGs acquired prior to the athlete’s first-year of participation served as the baseline for comparison for the third-year and post-COVID19 ECG. T-tests and two-sample z-tests were used as appropriate for statistical analysis. Results: Compared to matched first-year baseline, the QRS duration of post-COVID19 ECGs was significantly longer (102 ± 26 ms vs 100 ± 31 ms, p = 0.01, 95% CI 0.62-3.77), which was not seen when compared to matched third-year ECGs. There were no other significant differences between white and black athletes, or those of third-year ECGs compared to the matched first-year baseline. Conclusions: In this small cohort of 22 athletes, there was no significant change in heart rate, QRS duration, QT interval, or International Criteria classifications, including early repolarization and voltage, between first- and third-year ECGs of white and black athletes. Although the post-COVID19 QRS duration was significantly increased compared to first-year ECGs, the range was still within normal; there was no increase with respect to third-year ECGs. Further analysis of a larger sampling of athletes of different sexes and sports that also considers the impact of training on the post-COVID ECG is ongoing.

Evaluation of Atrial Electromechanical Delay and Left Atrial Phasic Function in Individuals with Electrocardiographic Early Repolarization Pattern.

Atrial electromechanical delay (EMD) and left atrial (LA) phasic function have been demonstrated to be predictors for the development of atrial fibrillation (AF). In the present study, we aimed to evaluate atrial EMD and LA phasic function in individuals with electrocardiographic early repolarization pattern (ERP). Eighty consecutive individuals with ERP and 40 age- and gender-matched control subjects without ERP were compared in this cross-sectional study. Atrial electromechanical coupling (Pa') was measured from lateral mitral annulus (Pa'lateral), septal mitral annulus (Pa'septal), and lateral tricuspid annulus (Pa'tricuspid) using tissue Doppler echocardiography to calculate intra- and inter-atrial EMD. LA maximal volume, LA minimal volume, and LA volume before atrial contraction were calculated using the biplane area-length method to assess LA phasic function. LA diameter, LA volume index, Pa'lateral, Pa'septal, Pa'tricuspid electrical activity and intra-left atrial EMD were significantly increased in the ERP patients. Mitral lateral, septal, tricuspid lateral annular tissue Doppler s' and e' waves were significantly decreased in the ERP patients. There were no significant difference between the groups in terms of interatrial EMD, intra-right atrial EMD, LA total emptying volume and LA total emptying fraction indicating LA reservoir function, LA passive emptying volume and LA passive emptying fraction indicating LA conduit function, LA active emptying volume and LA active emptying fraction indicating LA pump function. Left atrial EMD parameters are affected in individuals with ERP, but LA phasic functions are not affected. Further prospective studies are needed to clarify whether individuals with ERP have an increased susceptibility to AF.

Prognostic Assessment of Early Repolarization/J Wave Electrocardiographic Pattern in Patients With Stable Ischemic Heart Disease

Recent studies suggested that early repolarization (ER)/J wave at the electrocardiogram (ECG) is associated with increased risk of sudden death and ventricular arrhythmias in patients with acute myocardial infarction. In this study, we prospectively assessed whether ER/J wave has any long-term prognostic implications in patients with stable ischemic heart disease (IHD). We enrolled consecutive clinically stable patients with documented IHD, referred to undergo a routine ECG. ER (typical concave ST-segment elevation) and J wave were diagnosed according to prospectively defined criteria. The final population included 617 patients with documented IHD (455 men; age 68.1 ± 11years). ER/J wave was found in 138 patients (22.4%), 13 of whom (2.1%) showed ER and 133 (21.6%) a J wave. At a follow-up of 8.1±2.9years, 160 deaths occurred (25.9%), 60 (9.7%) attributed to cardiovascular causes. Total mortality was lower in patients with versus those without ER/J wave (18.8% vs 28.0%; hazard ratio [HR] 0.61, 95% confidence interval [CI] 0.40 to 0.93, p=0.02). The difference, however, was not significant after adjustment for confounding clinical variables (HR 0.78, 95% CI 0.51 to 1.19, p=0.25). No significant difference was found in cardiovascular death between patients with (7.2%) and those without (10.4%) ER/J wave (adjusted HR 0.78, 95% CI 0.40 to 1.55, p=0.48). Similar results were obtained for ER and J wave separately, and for ECG location of ER/J wave (inferior or lateral/precordial) and type of J wave (notched or slurred). The ER/J wave pattern at the ECG is not associated with increased risk of long-term mortality in clinically stable patients with a documented history of IHD.

E-cigarettes and their lone constituents induce cardiac arrhythmia and conduction defects in mice

E-cigarette use has surged, but the long-term health effects remain unknown. E-cigarette aerosols containing nicotine and acrolein, a combustion and e-cigarette byproduct, may impair cardiac electrophysiology through autonomic imbalance. Here we show in mouse electrocardiograms that acute inhalation of e-cigarette aerosols disturbs cardiac conduction, in part through parasympathetic modulation. We demonstrate that, similar to acrolein or combustible cigarette smoke, aerosols from e-cigarette solvents (vegetable glycerin and propylene glycol) induce bradycardia, bradyarrhythmias, and elevations in heart rate variability during inhalation exposure, with inverse post-exposure effects. These effects are slighter with tobacco- or menthol-flavored aerosols containing nicotine, and in female mice. Yet, menthol-flavored and PG aerosols also increase ventricular arrhythmias and augment early ventricular repolarization (J amplitude), while menthol uniquely alters atrial and atrioventricular conduction. Exposure to e-cigarette aerosols from vegetable glycerin and its byproduct, acrolein, diminish heart rate and early repolarization. The pro-arrhythmic effects of solvent aerosols on ventricular repolarization and heart rate variability depend partly on parasympathetic modulation, whereas ventricular arrhythmias positively associate with early repolarization dependent on the presence of nicotine. Our study indicates that chemical constituents of e-cigarettes could contribute to cardiac risk by provoking pro-arrhythmic changes and stimulating autonomic reflexes.

Evaluation of the relationship between monocyte to HDL ratio with STEMI, STEMI severity, thrombosis, and early repolarization

Introduction Due to the relationship between high maximum heart rate (MHR) values ​​and the severity of coronary atherosclerosis and cardiac events, as well as standard features and clinical outcomes of early repolarization significant and myocardial infarction with ST-segment elevation, this study investigated the relationship between monocyte to HDL ratio and STEMI, STEMI severity, Thrombosis, and early repolarization were performed. Method This cross-sectional prospective observational study was performed on STEMI patients referred to Imam Khomeini Hospital in Ahvaz in 1399. In this study, STEMI patients and individuals with referred early repolarization patterns are evaluated during the first 12 hours after the onset of pain and used for statistical analysis of SPSS software version 22. Results: In this study, 36 patients have studied with a mean age of 61.6±14.4; 23 patients were male, and the rest were female. The ratio of monocytes to HDL in STEMI patients varied based on the age and sex of the patients. The mean MHR in STEMI patients based on PCI need was 16.4±2.9 in patients in need and 20.5±2.1 in patients who were candidates for CABG. The ratio of monocytes to HDL in STEMI patients varied based on the occurrence and severity of thrombosis.

Protein Kinase D1 Regulates Cardiac Hypertrophy, Potassium Channel Remodeling, and Arrhythmias in Heart Failure.

Background Structural and electrophysiological remodeling characterize heart failure (HF) enhancing arrhythmias. PKD1 (protein kinase D1) is upregulated in HF and mediates pathological hypertrophic signaling, but its role in K+ channel remodeling and arrhythmogenesis in HF is unknown. Methods and Results We performed echocardiography, electrophysiology, and expression analysis in wild-type and PKD1 cardiomyocyte-specific knockout (cKO) mice following transverse aortic constriction (TAC). PKD1-cKO mice exhibited significantly less cardiac hypertrophy post-TAC and were protected from early decline in cardiac contractile function (3 weeks post-TAC) but not the progression to HF at 7 weeks post-TAC. Wild-type mice exhibited ventricular action potential duration prolongation at 8 weeks post-TAC, which was attenuated in PKD1-cKO, consistent with larger K+ currents via the transient outward current, sustained current, inward rectifier K+ current, and rapid delayed rectifier K+ current and increased expression of corresponding K+ channels. Conversely, reduction of slowly inactivating K+ current was independent of PKD1 in HF. Acute PKD inhibition slightly increased transient outward current in TAC and sham wild-type myocytes but did not alter other K+ currents. Sham PKD1-cKO versus wild-type also exhibited larger transient outward current and faster early action potential repolarization. Tachypacing-induced action potential duration alternans in TAC animals was increased and independent of PKD1, but diastolic arrhythmogenic activities were reduced in PKD1-cKO. Conclusions Our data indicate an important role for PKD1 in the HF-related hypertrophic response and K+ channel downregulation. Therefore, PKD1 inhibition may represent a therapeutic strategy to reduce hypertrophy and arrhythmias; however, PKD1 inhibition may not prevent disease progression and reduced contractility in HF.

Early repolarization in adolescent athletes: A gender comparison of ECG and echocardiographic characteristics.

The early repolarization pattern (ERp) is an electrocardiographic finding previously associated with arrhythmic risk in adults. The purpose of this study is to evaluate the prevalence and characteristics of ERp in a group of adolescent athletes according to gender. Furthermore, potential associations with clinical, electrocardiographic, and echocardiographic parameters are explored. In this cross-sectional study young athletes (age < 18 years) were consecutively enrolled during the annual pre-participation evaluation, undergoing also transthoracic echocardiography assessment from January 2015 to March 2020. The prevalence of ERp was 27% in the whole population. Athletes with ERp were more frequently men practicing endurance sports. Women with ERp showed lower heart rate at rest, greater posterior, and relative ventricular wall thickness than those without ERp. Men with ERp presented higher systolic blood pressure at peak exercise, greater septal wall thickness, and indexed left ventricular mass than those without ERp. Both genders with ERp showed increased QRS voltage and narrower QRS duration. The ERp phenotype in men was more frequently notched with higher amplitude and ascending ST segment. Women's ERp presented more frequently a slurred morphology, especially in the inferior leads, and horizontal ST slope. No differences emerged in the occurrence of arrhythmias at rest and during maximal exercise test between groups, even considering higher risk phenotypes. ERp is an ECG finding compatible with normal cardiac adaptations to training in young athletes. ERp demonstrated gender differences regarding phenotypes previously associated with increased cardiovascular risk, not showing any differences in arrhythmias during maximal exercise test.

Gender-Specific Differences In Electrocardiographic Recordings

Studies have reported gender differences in electrocardiographic (ECG) recordings. Specifically, females are reported to have higher heart rates (HR), shorter PR intervals, longer QT intervals, lower ECG voltages, ST segment deviations, and a greater prevalence of sinus arrhythmia. Yet, many studies report the need for more research on differences in ECG recordings in male and females. PURPOSE: To examine whether there are significant gender differences in ECG recordings. METHODS: A total of 104 active participants, including 34 male (M, age = 24.6 ± 10.3 yrs) and 70 females (F, age = 26.6 ± 12.2 yrs) were included in this study. Participants were excluded from the study if they had a positive disease history or if they indicated use of any medication that is reported to effect cardiac conduction. A standard 12-lead ECG was recorded after 5 minutes of supine rest. ANOVA was used to test for a significant effect of gender on heart rate (HR), PR interval, QTc interval, P axis, QRS axis, T axis, QRS/T Angle and on voltage criteria for left ventricular hypertrophy (LVH) based on the Cornell product (CP) and Sokolow-Lyon (SL). RESULTS: Significant differences between M and F subjects were found for HR (M = 58.1 ± 12.2; F = 66.4 ± 11.3 bpm, p < .05), PR interval duration (M = 167.7 ± 30.9; F = 153.3 ± 26.7 ms, p < .05), QTc duration (M = 385.1 ± 25.8; F = 391.4 ± 20.4 ms, p < .05), CP criterion (M = 1185.0 ± 734.6; F = 521.8 ± 360.5 mVms, p < 0.001) and SL criterion (M = 36.6 ± 9.9; F = 23.6 ± 7.6 mm, p < 0.001) for LVH. There were no significant differences between M and F in the P axis, QRS axis, T axis, or QRS/T Angle. The M subjects had a greater prevalence of sinus arrhythmia (M = 23.5%; F = 18.6%), 1st degree atrioventricular block (M = 11.8%; F = 2.9%), and early repolarization (M = 14.7%; F = 1.4%) compared to the F subjects. CONCLUSIONS: Similar to other studies, we found that the male participants had a lower heart rate, longer PR interval, shorter QTc interval, and overall greater ECG voltages in comparison to female participants. However, we did not find a significant gender effect on P axis, QRS axis, T axis or QRS/T angle. The molecular basis for gender differences in the electrical activity of the heart has not been clearly determined but warrants further study.