Association between electrocardiographic features and mortality in COVID‐19 patients

BackgroundCardiovascular events have been reported in the setting of coronavirus disease‐19 (COVID‐19). It has been hypothesized that systemic inflammation may aggravate arrhythmias or trigger new‐onset conduction abnormalities. However, the specific type and distribution of electrocardiographic disturbances in COVID‐19 as well as their influence on mortality remain to be fully characterized.MethodsElectrocardiograms (ECGs) were obtained from 186 COVID‐19‐positive patients at a large tertiary care hospital in Northern Nevada. The following arrhythmias were identified by cardiologists: sinus bradycardia, sinus tachycardia, atrial fibrillation (A‐Fib), atrial flutter, multifocal atrial tachycardia (MAT), premature atrial contraction (PAC), premature ventricular contraction (PVC), atrioventricular block (AVB), and right bundle branch block (RBBB). The mean PR interval, QRS duration, and corrected QT interval were documented. Fisher''s exact test was used to compare the ECG features of patients who died during the hospitalization with those who survived. The influence of ECG features on mortality was assessed with multivariable logistic regression analysis.ResultsA‐Fib, atrial flutter, and ST‐segment depression were predictive of mortality. In addition, the mean ventricular rate was higher among patients who died as compared to those who survived. The use of therapeutic anticoagulation was associated with reduced odds of death; however, this association did not reach statistical significance.ConclusionThe underlying pathogenesis of COVID‐19‐associated arrhythmias remains to be established, but we postulate that systemic inflammation and/or hypoxia may induce potentially lethal conduction abnormalities in affected individuals. Longitudinal studies are warranted to evaluate the risk factors, pathogenesis, and management of COVID‐19‐associated cardiac arrhythmias.     

The de Winter electrocardiographic pattern evolves to ST elevation in acute total left main occlusion: A case series

The de Winter electrocardiographic (ECG) pattern was characterized by upsloping ST‐segment depressions, tall and positive symmetrical T waves in precordial leads. This rare ECG pattern was recognized as an indication of proximal left anterior descending artery occlusion. Less commonly, this ECG pattern was reported in association with occlusion of other coronary artery segments. We present three cases of the de Winter pattern associated with acute total left main occlusion. This pattern may evolve to ST elevation within hours of presentation. Widespread upsloping ST‐segment depressions from V₂–V₆, centered on V₅ were observed in these patients.     

Enhanced detection of abnormalities in heart rate variability and dynamics by 7‐day continuous ECG monitoring

BackgroundThe analysis of heart rate variability (HRV) and heart rate (HR) dynamics by Holter ECG has been standardized to 24 hs, but longer‐term continuous ECG monitoring has become available in clinical practice. We investigated the effects of long‐term ECG on the assessment of HRV and HR dynamics.MethodsIntraweek variations in HRV and HR dynamics were analyzed in 107 outpatients with sinus rhythm. ECG was recorded continuously for 7 days with a flexible, codeless, waterproof sensor attached on the upper chest wall. Data were divided into seven 24‐h segments, and standard time‐ and frequency‐domain HRV and nonlinear HR dynamics indices were computed for each segment.ResultsThe intraweek coefficients of variance of HRV and HR dynamics indices ranged from 2.9% to 26.0% and were smaller for frequency‐domain than for time‐domain indices, and for indices reflecting slower HR fluctuations than faster fluctuations. The indices with large variance often showed transient abnormalities from day to day over 7 days, reducing the positive predictive accuracy of the 24‐h ECG for detecting persistent abnormalities over 7 days. Conversely, 7‐day ECG provided 2.3‐ to 6.5‐fold increase in sensitivity to detect persistent plus transient abnormalities compared with 24‐h ECG. It detected an average of 1.74 to 2.91 times as many abnormal indices as 24‐h ECG.ConclusionsLong‐term ECG monitoring increases the accuracy and sensitivity of detecting persistent and transient abnormalities in HRV and HR dynamics and allows discrimination between the two types of abnormalities. Whether this discrimination improves risk stratification deserves further studies.     

Long‐term prognosis in patients with non‐type 1 Brugada electrocardiogram: Results from a large Japanese cohort of idiopathic ventricular fibrillation

BackgroundBrugada syndrome (BrS) is diagnosed in patients with ST‐segment elevation with spontaneous, drug‐induced, or fever‐induced type 1 morphology. Prognosis in type 2 or 3 Brugada electrocardiogram (Br‐ECG) patients remains unknown. The purpose of this study is to evaluate long‐term prognosis in non‐type 1 Br‐ECG patients in a large Japanese cohort of idiopathic ventricular fibrillation (The Japan Idiopathic Ventricular Fibrillation Study [J‐IVFS]).MethodsFrom 567 patients with Br‐ECG in J‐IVFS, a total of 28 consecutive non‐type 1 patients who underwent programmed electrical stimulation (PES) (median age: 58 years, all male, previous sustained ventricular tachyarrhythmias [VTs] 1, syncope 11, asymptomatic 16) were enrolled. Cardiac events (CEs: sudden cardiac death or sustained VT/ventricular fibrillation) during the follow‐up period were examined.ResultsDuring a median follow‐up of 136 months, four patients (14%) had CEs. None of patients with PES‐ have experienced CEs. There was no statistically significant clinical risk factor for the development of CEs. Using the Kaplan–Meier method, the event‐free rate significantly decreased in a group with all 3 risk factors (symptom, wide QRS complex in lead V₂, and positive PES) (p = .01).ConclusionsOur study revealed long‐term prognosis in patients with non‐type 1 Br‐ECG. The combination analysis of these risk factors may be useful for the risk stratification of CEs in non‐type 1 Br‐ECG patients. The present study suggests that the patients with all these parameters showed high risk for CEs and need to be carefully followed.     

Night‐to‐night variability of sleep apnea detected by cyclic variation of heart rate during long‐term continuous ECG monitoring

BackgroundSleep apnea is common in patients with cardiovascular disease and is a factor that worsens prognosis. Holter 24‐h ECG screening for sleep apnea is beneficial in the care of these patients, but due to high night‐to‐night variability of sleep apnea, it can lead to misdiagnosis and misclassification of disease severity.MethodsTo investigate the long‐term dynamic behavior of sleep apnea, seven‐day ECGs recorded with a patch ECG recorder in 120 patients were analyzed for the cyclic variation of heart rate (CVHR) during sleep periods as determined by a built‐in three‐axis accelerometer.ResultsThe frequency of CVHR (Fcv) showed considerable night‐to‐night variability (coefficient of variance, 66 ± 35%), which was consistent with the night‐to‐night variability in apnea‐hypopnea index and oxygen desaturation index reported in earlier studies. In patients with presumed moderate‐to‐severe sleep apnea (Fcv > 15 cph at least one night), it was missed on 62% of nights, and on at least one night in 88% of patients. The CV of Fcv was negatively correlated with the average of Fcv, suggesting that patients with mild sleep apnea show greater night‐to‐night variability and would benefit from long‐term assessment. The average Fcv was higher in the supine position, but the night‐to‐night variability was not explained by the night‐to‐night variability of time spent in the supine position.ConclusionsCVHR analysis of long‐term ambulatory ECG recordings is useful for improving the reliability of screening for sleep apnea without placing an extra burden on patients with cardiovascular disease and their care.     

Electrocardiogram evolution of acute anterior ST‐segment elevation myocardial infarction following pericarditis

Electrocardiogram is a powerful tool for differentiating acute ST‐segment elevation myocardial infarction (STEMI) and pericarditis. However, an unusual ECG presentation of the simultaneous occurrence of the two conditions has not been reported previously. In this article, we report a case of ECG evolution of acute anterior STEMI following pericarditis with pericardial effusion (PE) and find that QRS complex widening in ECG lead with maximal ST‐segment elevation is also applicable for identifying STEMI even in patients with prior pericarditis. Undoubtedly, our case can help prevent emergency physicians from making incorrect diagnoses and administering inappropriate treatments.     

Epsilon‐Like Electrocardiographic Pattern in a Patient with Brugada Syndrome

Both Brugada syndrome (BrS) and arrhythmogenic right ventricle dysplasia/cardiomyopathy (ARVD/C) can cause repolarization abnormalities in right precordial leads and predispose to sudden cardiac death (SCD) due to ventricular arrhythmias. Although there is controversy over whether BrS is distinct from ARVD/C, it is believed that both are different clinical entities with respect to both the clinical presentation and the genetic predisposition. The coexistence of these two relatively rare clinical entities is also reported, but, some hypothesized that it is more possible that disease of the right ventricular muscle might accentuate the Brugada electrocardiographic pattern. In clinic practice, there may be cases where the dividing line is not so clear. We report a 33‐year‐old male presenting with recurrent syncope, who has a peculiar pattern of coved‐type ST‐segment elevation (ST‐SE) with epsilon‐like wave in right precordial leads.     

The value of ECG changes in risk stratification of COVID‐19 patients

BackgroundThere is growing evidence of cardiac injury in COVID‐19. Our purpose was to assess the prognostic value of serial electrocardiograms in COVID‐19 patients.MethodsWe evaluated 269 consecutive patients admitted to our center with confirmed SARS‐CoV‐2 infection. ECGs available at admission and after 1 week from hospitalization were assessed. We evaluated the correlation between ECGs findings and major adverse events (MAE) as the composite of intra‐hospital all‐cause mortality or need for invasive mechanical ventilation. Abnormal ECGs were defined if primary ST‐T segment alterations, left ventricular hypertrophy, tachy or bradyarrhythmias and any new AV, bundle blocks or significant morphology alterations (e.g., new Q pathological waves) were present.ResultsAbnormal ECG at admission (106/216) and elevated baseline troponin values were more common in patients who developed MAE (p = .04 and p = .02, respectively). Concerning ECGs recorded after 7 days (159), abnormal findings were reported in 53.5% of patients and they were more frequent in those with MAE (p = .001). Among abnormal ECGs, ischemic alterations and left ventricular hypertrophy were significantly associated with a higher MAE rate. The multivariable analysis showed that the presence of abnormal ECG at 7 days of hospitalization was an independent predictor of MAE (HR 3.2; 95% CI 1.2–8.7; p = .02). Furthermore, patients with abnormal ECG at 7 days more often required transfer to the intensive care unit (p = .01) or renal replacement therapy (p = .04).ConclusionsPatients with COVID‐19 should receive ECG at admission but also during their hospital stay. Indeed, electrocardiographic alterations during hospitalization are associated with MAE and infection severity.     

Trends in seroprevalence of SARS‐CoV‐2 and infection fatality rate in the Norwegian population through the first year of the COVID‐19 pandemic

BackgroundInfection with the novel coronavirus SARS‐CoV‐2 induces antibodies that can be used as a proxy for COVID‐19. We present a repeated nationwide cross‐sectional study assessing the seroprevalence of SARS‐CoV‐2, the infection fatality rate (IFR), and infection hospitalization rate (IHR) during the first year of the pandemic in Norway.MethodsResidual serum samples were solicited in April/May 2020 (Round 1), in July/August 2020 (Round 2) and in January 2021 (Round 3). Antibodies against SARS‐CoV‐2 were measured using a flow cytometer‐based assay. Aggregate data on confirmed cases, COVID‐19‐associated deaths and hospitalizations were obtained from the Emergency preparedness registry for COVID‐19 (Beredt C19), and the seroprevalence estimates were used to estimate IFR and IHR.ResultsAntibodies against SARS‐CoV‐2 were measured in 4840 samples. The estimated seroprevalence increased from 0.8% (95% credible interval [CrI] 0.4%–1.3%) after the first wave of the pandemic (Rounds 1 and 2 combined) to 3.2% (95% CrI 2.3%–4.2%) (Round 3). The IFR and IHR were higher in the first wave than in the second wave and increased with age. The IFR was 0.2% (95% CrI 0.1%–0.3%), and IHR was 0.9% (95% CrI 0.6%–1.5%) for the second wave.ConclusionsThe seroprevalence estimates show a cumulative increase of SARS‐CoV‐2 infections over time in the Norwegian population and suggest some under‐recording of confirmed cases. The IFR and IHR were low, corresponding to the relatively low number of COVID‐19‐associated deaths and hospitalizations in Norway. Most of the Norwegian population was still susceptible to SARS‐CoV‐2 infection after the first year of the pandemic.     

Holter ECG in evaluating myocardial ischemia. Validation using the exercise test

OBJECTIVES: Validation of ST-T ischemic changes in the Holter system by those recorded in the 12-lead ECG during the exercise test. DESIGN: The changes induced by the exercise test in the ST segment of the two Holter leads--aVF e V5 like--were compared with the changes simultaneously registered in the 12-lead ECG. SETTING: Exercise Test Laboratory and Holter Laboratory of the UTIC-Arsénio Cordeiro. Hospital de Santa Maria de Lisboa. PATIENTS: 31 patients, 23 male and 8 female, with a mean age of 55 +/- 7 years, 84% with ischemic heart disease. METHODS: The patients underwent a treadmill exercise test. 28 with the Bruce protocol and 3 with the Naugton protocol, during which the electrocardiogram was registered simultaneously with a 2-channel Holter recorder and by a conventional 12-lead system. The changes induced in the ST segment in the two systems were compared. RESULTS: The results of the two tests were concordant in 94% of the patients. In 4 patients (13%) there was not a good correlation between the inferior and anterior leads of the two methods, which diverged mainly between the Holter lead aVF and the inferior leads of the conventional ECG. The morphology of the ST depression was similar in both methods, and the severity of ST depression as judged by its amplitude showed an excellent positive linear correlation (r = 0.8542, p less than 0.001). CONCLUSIONS: The sensitivity and the specificity of the Holter system is similar to the conventional 12-lead ECG in detecting ischemic changes during exercise whenever they have electrocardiographic evidence.     

Some Controversies about Early Repolarization: The Haïssaguerre Syndrome

Controversy has followed the groundbreaking and cornerstone paper of Haïssaguerre et al. Much of this controversy has been due to the use of the term “early repolarization pattern” and possible waveform morphologies on the standard 12‐lead ECG ( it is 10 second strip) that could predict who will manifest the malignant arrhythmogenic syndrome described by Haïssaguerre et al. The standard ECG definition of early repolarization pattern (ERP) or early repolarization variant (ERV) since then has changed its clinical meaning for a surface electrocardiographic waveform from benign to malignant. The new definition of ERP/ERV contains only J wave but ST‐segment elevation is no more obligatory. In the old definition, early repolarization pattern (ERP) or early repolarization variant (ERV) 3 is a well‐recognized idiopathic electrocardiographic phenomenon considered to be present when at least two adjacent precordial leads show elevation of the ST segment, with values equal or higher than 1 mm. In the new electrocardiographic ERP concept, the ST segment may or may not be elevated and can be up‐sloping, horizontal or down‐sloping while in the old ERP/ERV concept it must be elevated at least 1 mm in at least two adjacent leads and the variant is characterized by a diffuse elevation of the ST segment of upper concavity, ending in a positive T wave of V₂ to V₄ or V₅ and prominent J wave and ST‐segment elevation predominantly in left precordial leads. The phenomenon constitutes a normal variant; it is almost a rule in athletes (present in 89% of the cases in this universe).     

Electrocardiographic characteristics of premature ventricular contractions in subjects with type 1 pattern of Brugada syndrome

Background

The ECG characteristics of premature ventricular contractions (PVCs) in subjects with Brugada syndrome (BrS) phenotype were investigated.

Methods and results

A total of 96 patients with type 1 ECG pattern of BrS were screened for PVCs. The study population consisted of 10 male individuals (mean age 41.9 ± 5.6 years) with spontaneous (n = 2) or drug-induced (n = 8) type 1 ECG phenotype of BrS and PVCs. Twenty patients (11 males, age 44.6 ± 15.1 years) with idiopathic right ventricular outflow tract (RVOT) PVCs (LBBB/inferior axis morphology with a negative QRS complex in lead aVL) successfully ablated from an endocardial site were also included in the study, and served as comparative controls. Six subjects with BrS phenotype (five during drug challenge) displayed PVCs with LBBB/inferior axis morphology and negative QRS complex in aVL lead which indicates an RVOT origin. The ECG characteristics of PVCs with LBBB/inferior axis in subjects with BrS and idiopathic RVOT arrhythmia were subsequently compared. QRS duration in inferior (p = 0.001) and right precordial leads (p < 0.001) was significantly longer in subjects with BrS phenotype. The RS interval in lead V2 was also significantly prolonged in individuals with BrS phenotype (p = 0.016). Subjects with BrS phenotype exhibited an increased intrinsicoid deflection time measured in right precordial leads compared to those with idiopathic RVOT PVCs (46.0 ± 7.6 vs. 27.2 ± 9.5 ms, p < 0.001). Finally, a pseudo-delta wave in precordial leads was more commonly observed in subjects with BrS ECG pattern (p = 0.029).

Conclusions

PVCs in BrS usually originate from the RVOT and display specific ECG characteristics that might be indicative of an epicardial origin. The prolonged interval criteria may be related to a localized epicardial conduction delay.     

Necklace‐embedded electrocardiogram for the detection and diagnosis of atrial fibrillation

BackgroundAtrial fibrillation (AF) is the major cause of stroke since approximately 25% of all strokes are of cardioembolic‐origin. The detection and diagnosis of AF are often challenging due to the asymptomatic and intermittent nature of AF.HypothesisA wearable electrocardiogram (ECG)‐device could increase the likelihood of AF detection. The aim of this study was to evaluate the feasibility and reliability of a novel, consumer‐grade, single‐lead ECG recording device (Necklace‐ECG) for screening, identifying and diagnosing of AF both by a cardiologist and automated AF‐detection algorithms.MethodsA thirty‐second ECG was recorded with the Necklace‐ECG device from two positions; between the palms (palm) and between the palm and the chest (chest). Simultaneously registered 3‐lead ECGs (Holter) served as a golden standard for the final rhythm diagnosis. Two cardiologists interpreted independently in a blinded fashion the Necklace‐ECG recordings from 145 patients (66 AF and 79 sinus rhythm, SR). In addition, the Necklace‐ECG recordings were analyzed with an automatic AF detection algorithm.ResultsTwo cardiologists diagnosed the correct rhythm of the interpretable Necklace‐ECG with a mean sensitivity of 97.2% and 99.1% (palm and chest, respectively) and specificity of 100% and 98.5%. The automatic arrhythmia algorithm detected the correct rhythm with a sensitivity of 94.7% and 98.3% (palm and chest) and specificity of 100% of the interpretable measurements.ConclusionsThe novel Necklace‐ECG device is able to detect AF with high sensitivity and specificity as evaluated both by cardiologists and an automated AF‐detection algorithm. Thus, the wearable Necklace‐ECG is a new, promising method for AF screening. Clinical trial registration: Study was registered in the ClinicalTrials.gov database ({"type":"clinical-trial","attrs":{"text":"NCT03753139","term_id":"NCT03753139"}}NCT03753139).     

Prognostic significance of ST segment depression in lateral leads I, aVL, V5 and V6 on the admission electrocardiogram in patients with a first acute myocardial infarction without ST segment elevation

OBJECTIVESWe sought to investigate the short-term prognostic value of the admission electrocardiogram (ECG) in patients with a first acute myocardial infarction (MI) without ST segment elevation.BACKGROUNDST segment depression on hospital admission predicts a worse outcome in patients with a first acute MI, but the prognostic information provided by the location of ST segment depression remains unclear.METHODSIn 432 patients with a first acute MI without Q waves or ≥0.1 mV of ST segment elevation, we evaluated the ability of the initial ECG to predict in-hospital death.RESULTSThe presence, magnitude and extent of ST segment depression were associated with an increased mortality, but the only electrocardiographic variable that was significant in predicting death after adjusting for baseline predictors was ST segment depression in two or more lateral (I, aVL, V₅, or V₆) leads (odds ratio 3.5, 95% confidence interval 1.2 to 10.6). Patients with lateral ST segment depression (n = 91, 21%) had higher rates of death (14.3% vs. 2.6%, p < 0.001), severe heart failure (14.3% vs. 4.1%, p < 0.001) and angina with electrocardiographic changes (20.0% vs. 11.6%, p = 0.04) than did the remaining patients, even though they had similar peak creatine kinase, MB fraction levels (129 ± 96 vs. 122 ± 92 IU/liter, p = NS). In contrast, ST segment depression not involving the lateral leads did not predict a poor outcome. Among patients who were catheterized, those with lateral ST segment depression had a lower left ventricular ejection fraction (57 ± 12% vs. 66 ± 13%, p = 0.001) and more frequent left main coronary artery or three-vessel disease than did the remaining patients (60% vs. 22%, p < 0.001).CONCLUSIONSIn patients with a first non–ST segment elevation acute MI, ST segment depression in the lateral leads on hospital admission predicts a poor in-hospital outcome.     

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

BackgroundInverted 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.MethodsA 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.ResultsThe 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]).ConclusionsThe 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.     

Serum tumor necrosis factor‐α, interleukin‐1β, interleukin‐6, and interleukin‐17 relate to anxiety and depression risks to some extent in non‐small cell lung cancer survivor

IntroductionInflammatory cytokines are proposed as modulators for the pathogenesis of anxiety and depression (anxiety/depression), and anxiety/depression are frequently existed in non‐small cell lung cancer (NSCLC) survivors. However, no published study has explored the association of inflammation cytokines with anxiety/depression in NSCLC survivors.ObjectivesWe aimed to evaluate serum tumor necrosis factor‐α (TNF‐α), interleukin‐1 beta (IL‐1β), interleukin‐6 (IL‐6), interleukin‐17 (IL‐17) levels, and their correlations with anxiety/depression in NSCLC survivors.MethodsTotally, 217 NSCLC survivors and 200 controls were recruited. Then, inflammatory cytokines in serum samples were detected by enzyme‐linked immunosorbent assay (ELISA). Besides, their anxiety/depression status was assessed by Hospital Anxiety and Depression Scale (HADS).ResultsHADS‐anxiety score, anxiety rate, anxiety severity, HADS‐depression score, depression rate, and depression severity were all increased in NSCLC survivors compared with controls (all P < 0.001). Regarding inflammatory cytokines, TNF‐α, IL‐1β, and IL‐17 levels were higher (all P < 0.01), while IL‐6 (P = 0.105) level was of no difference in NSCLC survivors compared with controls. Furthermore, TNF‐α, IL‐1β, IL‐6, and IL‐17 were all positively associated with HADS‐A score (all P < 0.05), anxiety occurrence (all P < 0.05), HADS‐D score (all P < 0.05), and depression occurrence (all P < 0.05) in NSCLC survivors, while the correlation‐coefficients were weak. Additionally, multivariate logistic regression analyses disclosed that TNF‐α (both P < 0.05) and IL‐1β (both P < 0.001) were independently correlated with increased anxiety and depression risks in NSCLC survivors.ConclusionSerum TNF‐α, IL‐1β, IL‐6, and IL‐17 are related to increased anxiety and depression risks to some extent in NSCLC survivors.     

Differential diagnosis between LQT1 and LQT2 by QT/RR relationships using 24‐hour Holter monitoring: A multicenter cross‐sectional study

BackgroundThe clinical course and therapeutic strategies in the congenital long QT syndrome (LQTS) are genotype‐specific. However, accurate estimation of LQTS genotype is often difficult from the standard 12‐lead ECG.ObjectivesThis study aims to evaluate the utility of QT/RR slope analysis by the 24‐hour Holter monitoring for differential diagnosis of LQTS genotype between LQT1 and LQT2.MethodsThis cross‐sectional study enrolled 54 genetically identified LQTS patients (29 LQT1 and 25 LQT2) recruited from three medical institutions. The QT‐apex (QTa) interval and the QT‐end (QTe) interval at each 15‐second were plotted against the RR intervals, and the linear regression (QTa/RR and QTe/RR slopes, respectively) was calculated from the entire 24‐hour and separately during the day or night‐time periods of the Holter recordings.ResultsThe QTe/RR and QTa/RR slopes at the entire 24‐hour were significantly steeper in LQT2 compared to those in LQT1 patients (0.262 ± 0.063 vs. 0.204 ± 0.055, p = .0007; 0.233 ± 0.052 vs. 0.181 ± 0.040, p = .0002, respectively). The QTe interval was significantly longer, and QTe/RR and QTa/RR slopes at daytime were significantly steeper in LQT2 than in LQT1 patients. The receiver operating curve analysis revealed that the QTa/RR slope of 0.211 at the entire 24‐hour Holter was the best cutoff value for differential diagnosis between LQT1 and LQT2 (sensitivity: 80.0%, specificity: 75.0%, and area under curve: 0.804 [95%CI = 0.68–0.93]).ConclusionThe continuous 24‐hour QT/RR analysis using the Holter monitoring may be useful to predict the genotype of congenital LQTS, particularly for LQT1 and LQT2.     

The prognostic significance of electrocardiography findings in patients with coronavirus disease 2019: A retrospective study

BackgroundCoronavirus disease 2019 (COVID‐19) has reached a pandemic level. Cardiac injury is not uncommon among COVID‐19 patients. We sought to describe the electrocardiographic characteristics and to identify the prognostic significance of electrocardiography (ECG) findings of patients with COVID‐19.HypothesisECG abnormality was associated with higher risk of death.MethodsConsecutive patients with laboratory‐confirmed COVID‐19 and definite in‐hospital outcome were retrospectively included. Demographic characteristics and clinical data were extracted from medical record. Initial ECGs at admission or during hospitalization were reviewed. A point‐based scoring system of abnormal ECG findings was formed, in which 1 point each was assigned for the presence of axis deviation, arrhythmias, atrioventricular block, conduction tissue disease, QTc interval prolongation, pathological Q wave, ST‐segment change, and T‐wave change. The association between abnormal ECG scores and in‐hospital mortality was assessed in multivariable Cox regression models.ResultsA total of 306 patients (mean 62.84 ± 14.69 years old, 48.0% male) were included. T‐wave change (31.7%), QTc interval prolongation (30.1%), and arrhythmias (16.3%) were three most common found ECG abnormalities. 30 (9.80%) patients died during hospitalization. Abnormal ECG scores were significantly higher among non‐survivors (median 2 points vs 1 point, p < 0.001). The risk of in‐hospital death increased by a factor of 1.478 (HR 1.478, 95% CI 1.131–1.933, p = 0.004) after adjusted by age, comorbidities, cardiac injury and treatments.ConclusionsECG abnormality was common in patients admitted for COVID‐19 and was associated with adverse in‐hospital outcome. In‐hospital mortality risk increased with increasing abnormal ECG scores.     

The impact of hydroxychloroquine–azithromycin combination on Tpeak‐to‐end and Tpeak‐to‐end/QT ratio during a short treatment course

BackgroundSince there was no proven treatment of coronavirus disease 2019 (COVID‐19), hydroxychloroquine–azithromycin (HCQ‐AZM) combination is being used in different countries as a treatment option. Many controversies exist related to the safety and effectiveness of this combination, and questions about how HCQ‐AZM combination affects the ventricular repolarization are still unknown.ObjectiveThe aim of the study was to show whether the hydroxychloroquine–azithromycin (HCQ‐AZM) combination prolonged Tpeak‐to‐end (TpTe) duration and TpTe/QT interval ratio or not.MethodsOne hundred and twenty‐six consequent COVID‐19(+) patients meeting the study criteria were enrolled in this study. Baseline ECGs were obtained immediately after hospitalization and before commencing the HCQ‐AZM combination. On‐treatment ECG was obtained 24–48 hr after the loading dose of HCQ/AZM. ECG parameters including PR interval, QRS duration, QT interval, QTc interval, TpTe duration, and TpTe/QT interval ratio were assessed. Demographic and laboratory findings were collected from an electronic recording system.ResultsECGs of 126 COVID‐19(+) patients who received HCQ‐AZM combination were assessed. Mean baseline QTc (by Fridericia formula), TpTe, and TpTe/QT ratio were 420.0 ± 26.5 ms, 82.43 ± 9.77 ms, and 0.22 ± 0.02, respectively. On‐treatment QTc, TpTe and TpTe/QT ratio were 425.7 ± 27.18 ms, 85.17 ± 11.17 ms, and 0.22 ± 0.03, respectively. No statistically significant acute impacts of HCQ‐AZM combination on TpTe duration and TpTe/QT interval ratio were observed compared with baseline values. No ventricular tachycardia/fibrillation and the significant conduction delays were seen during in‐hospital follow‐up.ConclusionHCQ‐AZM combination increased TpTe duration. However, no significant impact on TpTe/QT interval ratio was observed.