Setoguchi T, Matsumoto N, Matsunaga Y
… +10 more, Otsuka N, Monden M, Fujito H, Yagi T, Matsumoto M, Suzuki Y, Fukamachi D, Yokoyama K, Okumura Y, Yamauchi T
BACKGROUND: Right-sided chest precordial electrocardiogram (ECG) leads (VR-VR) are critical for diagnosing right ventricular (RV) infarction complicating acute inferior wall myocardial infarction. However, obtaining thes...BACKGROUND: Right-sided chest precordial electrocardiogram (ECG) leads (VR-VR) are critical for diagnosing right ventricular (RV) infarction complicating acute inferior wall myocardial infarction. However, obtaining these leads in emergency settings can be time-consuming. This study compared measured and synthesized right-sided precordial ECGs to determine whether a synthesized ECG derived from a standard 12‑lead tracing can serve as a reliable alternative. METHODS: We retrospectively analyzed 38 patients (admitted between 2016 and 2024) with acute inferior wall myocardial infarction who underwent both measured and synthesized right-sided precordial ECGs. ST-segment deviation from the isoelectric line was quantified at the ST junction (STJ), at 40 ms (ST1), and 80 ms (ST2) thereafter for VR-VR. Agreement was evaluated using Pearson's correlation, Bland-Altman analysis, and receiver-operating-characteristic (ROC) curve analysis for the detection of RV infarction (ST elevation ≥0.1 mV in VR). RESULTS: Pearson's r for measured versus synthesized ECGs was 0.90 for VR, 0.84 for VR, and 0.78 for VR (all P < 0.001). Bland-Altman plots showed negligible bias (mean difference ≤ 0.02 mV) with narrow 95% limits of agreement (∼ ± 0.12 mV). Diagnostic performance was equivalent between synthesized and measured VR (ΔAUC = 0.0028; SE = 0.0551; 95% CI -0.105 to 0.111; z = 0.0505; P = 0.9598). CONCLUSIONS: Synthesized right-sided precordial ECGs derived from a standard 12‑lead tracing closely reproduce measured leads in acute inferior wall myocardial infarction and may enable rapid identification of RV infarction without delaying reperfusion therapy.
We report a 78-year-old asymptomatic woman with no cardiac history and unremarkable cardiac evaluation, referred for a pre-surgical ECG showing diffuse T-wave inversion. Following ventriculoperitoneal shunting for chroni...We report a 78-year-old asymptomatic woman with no cardiac history and unremarkable cardiac evaluation, referred for a pre-surgical ECG showing diffuse T-wave inversion. Following ventriculoperitoneal shunting for chronic normal-pressure hydrocephalus (NPH), her ECG gradually normalized, suggesting a reversible neurocardiac effect. This case highlights a not well documented association between chronic NPH and T-wave inversions, possibly mediated by autonomic dysregulation, and underscores the importance of considering extracardiac neurologic disorders in the ECG differential diagnosis.
BACKGROUND: Electrical disturbances are common complications after transcatheter aortic valve implantation (TAVI), particularly with self-expandable valves. Improved noninvasive markers are needed to identify patients at...BACKGROUND: Electrical disturbances are common complications after transcatheter aortic valve implantation (TAVI), particularly with self-expandable valves. Improved noninvasive markers are needed to identify patients at increased risk. The frontal QRS-T angle reflects ventricular electrical heterogeneity, but the prognostic value of its post-procedural change remains unclear. METHODS: In this single-center retrospective observational cohort study, consecutive patients undergoing self-expandable TAVI were analyzed. ΔQRS-T angle was defined as the difference between post and pre-procedural frontal QRS-T angles. The primary endpoint was the occurrence of electrical disturbances within 24 h, including new-onset bundle branch block, QRS prolongation >20 ms, high-grade atrioventricular block, or permanent pacemaker implantation (PPM). Logistic regression and receiver operating characteristic (ROC) analyses were performed. RESULTS: A total of 135 patients were included, of whom 66 (48.9%) developed electrical disturbances. ΔQRS-T angle was significantly greater in patients with electrical disturbances (median 24° vs. 7°, p = 0.01). In multivariable analysis, ΔQRS-T angle independently associated with electrical disturbances (odds ratio [OR] 1.02 per degree increase, 95% confidence interval [CI] 1.01-1.03, p = 0.006) and PPM implantation (OR 1.016 per degree increase, 95% CI 1.01-1.07, p = 0.02). ROC analysis demonstrated modest discrimination (area under the curve 0.619, 95% CI 0.519-0.719). A cut-off value of 46.5° yielded 45.5% sensitivity and 87.0% specificity. CONCLUSIONS: Post-procedural change in frontal QRS-T angle is independently associated with early electrical disturbances and pacemaker requirement after self-expandable TAVI. ΔQRS-T angle may provide complementary risk information but requires external validation before routine clinical application.
BACKGROUND: Fragmented QRS (fQRS) on electrocardiography reflects myocardial conduction abnormalities and has been proposed as a potential marker of atrial structural remodeling. However, its prognostic value for atrial...BACKGROUND: Fragmented QRS (fQRS) on electrocardiography reflects myocardial conduction abnormalities and has been proposed as a potential marker of atrial structural remodeling. However, its prognostic value for atrial tachyarrhythmia occurrence after catheter ablation for atrial fibrillation (AF) or atrial flutter (AFL) remains uncertain. We conducted a meta-analysis to clarify the association between fQRS and post-ablation atrial tachyarrhythmia occurrence. METHODS: PubMed, Embase, Web of Science, Wanfang, and CNKI were systematically searched for longitudinal observational studies evaluating the association between baseline or early peri-procedural fQRS and atrial tachyarrhythmia occurrence after catheter ablation for AF or AFL. The primary outcome was post-ablation atrial tachyarrhythmia, including AF, AFL, or atrial tachycardia. Risk ratios (RRs) with 95% confidence intervals (CIs) were pooled using random-effects models accounting for the influence of potential heterogeneity. RESULTS: Six cohort studies involving 1064 patients were included. During follow-up ranging from 3 to 43.2 months, 331 patients developed atrial tachyarrhythmia after ablation. The presence of fQRS was significantly associated with a higher risk of post-ablation atrial tachyarrhythmia occurrence (pooled RR = 2.11, 95% CI 1.55-2.87; I = 66%). This association remained consistent in subgroup analyses stratified by arrhythmia type (AF vs AFL), timing of fQRS assessment, and follow-up duration. CONCLUSIONS: Fragmented QRS is associated with a more than twofold increased risk of atrial tachyarrhythmia occurrence after catheter ablation for AF or AFL. As a simple and widely available electrocardiographic marker, fQRS may aid in pre-procedural risk stratification and individualized post-ablation management.
BACKGROUND: Masquerading bundle branch block (MBBB) is a rare and underrecognized electrocardiographic pattern characterized by features of both right and left bundle branch block on the same tracing. Unlike typical bifa...BACKGROUND: Masquerading bundle branch block (MBBB) is a rare and underrecognized electrocardiographic pattern characterized by features of both right and left bundle branch block on the same tracing. Unlike typical bifascicular block, MBBB is increasingly recognized as a marker of advanced and often bilateral His-Purkinje system disease, with potential progression to high-grade atrioventricular block. CASE PRESENTATION: We report the case of an 84-year-old woman with a history of atrial fibrillation, heart failure with preserved ejection fraction, chronic kidney disease, and aortic stenosis who presented with generalized weakness and severe hyponatremia. Electrocardiography (EKG) demonstrated atrial fibrillation with a wide QRS complex and right bundle branch block morphology in the precordial leads. Notably, there was absence of the expected terminal S wave in leads I and aVL with left axis deviation, consistent with masquerading bundle branch block. Comparison with prior electrocardiography revealed progression from bifascicular block to MBBB. During hospitalization, telemetry showed episodes of bradycardia with heart rates as low as 30 beats per minute, raising concern for advanced conduction system disease. The patient was managed conservatively and discharged with ambulatory rhythm monitoring and electrophysiology follow-up. DISCUSSION: MBBB represents a complex conduction disturbance often reflecting diffuse His-Purkinje system involvement rather than isolated right-sided conduction delay. It is frequently misclassified as right bundle branch block with left anterior fascicular block, leading to underrecognition of its clinical significance. Accumulating evidence suggests that MBBB is associated with a higher risk of progression to symptomatic bradyarrhythmias and advanced atrioventricular block. Recognition of its characteristic electrocardiographic features is essential for appropriate risk stratification and management, including consideration of prolonged monitoring or early electrophysiologic evaluation. CONCLUSION: Masquerading bundle branch block is an important but underrecognized electrocardiographic marker of advanced conduction system disease. Early identification may facilitate timely monitoring and intervention to prevent adverse outcomes related to conduction system failure.
BACKGROUND AND PURPOSE: Obesity is associated with distinct ECG manifestations due to altered body fat distribution, which may vary by race/ethnicity. However, few studies have evaluated these differences. METHODS: We an...BACKGROUND AND PURPOSE: Obesity is associated with distinct ECG manifestations due to altered body fat distribution, which may vary by race/ethnicity. However, few studies have evaluated these differences. METHODS: We analyzed 7315 participants (mean age 59.6 ± 13.5 years; 52.4% female; 51.5% non-Hispanic White, 24.5% non-Hispanic Black, 24.0% Mexican American) from NHANES III, excluding those with prior cardiovascular disease or missing ECGs. Obesity was defined as BMI ≥30 kg/m. Standard 12‑lead ECGs were recorded and processed centrally. ECG waveform amplitudes and durations, PR, QRS and QT intervals, and P-, QRS-, and T-wave axes were measured automatically with visual inspection. Multivariable linear regression assessed associations between obesity and ECG parameters overall and stratified by race/ethnicity. RESULTS: Obesity was associated with prolonged QRS, QT, and PR durations (differences [msec] obese vs. non-obese [95% CI]: 2.17 [1.43-2.90], 1.90 [0.87-3.01], and 4.82 [3.40-6.24], respectively; all p < 0.001), and more leftward P-, QRS-, and T-wave axes (differences [degrees]: -7.36 [-8.54, -6.18], -9.53 [-11.52, -7.53], -7.02 [-8.60, -5.43]; all p < 0.001). Obesity was further associated with lower R and S amplitudes and prolonged wave durations in nearly all leads, with exceptions in III and aVF. Most associations were consistent across races, though effects on S amplitude in V3/V4, R duration in aVL, and S duration in II were weaker in Mexican Americans and non-Hispanic Whites (interaction p = 0.01-0.03). CONCLUSION: Obesity influences ECG waveform amplitudes and durations, largely independent of race/ethnicity. These findings support non-race-specific ECG interpretation while highlighting potential limitations of amplitude- and duration-based criteria.
PRKAG2 cardiomyopathy exhibits distinctive P-wave abnormalities-including notching, axis deviation, inter-atrial block, and enlarged P-wave terminal force in lead V1 (PTFV1)-that reflect underlying atrial involvement. Th...PRKAG2 cardiomyopathy exhibits distinctive P-wave abnormalities-including notching, axis deviation, inter-atrial block, and enlarged P-wave terminal force in lead V1 (PTFV1)-that reflect underlying atrial involvement. These atrial electrocardiographic features, when integrated with comprehensive genetic testing, may enable earlier diagnosis, facilitating accurate genotype-phenotype correlation and refined risk stratification beyond traditional preexcitation or hypertrophy patterns, ultimately guiding timely intervention and family screening in this rare but potentially malignant inherited cardiac disorder.
40-year-old gentleman who underwent permanent pacemaker implantation for intermittent complete heart block had episodes of pacemaker mediated tachycardia on device logs. The cause for endless loop tachycardia was unique...40-year-old gentleman who underwent permanent pacemaker implantation for intermittent complete heart block had episodes of pacemaker mediated tachycardia on device logs. The cause for endless loop tachycardia was unique in this case. The mechanism behind the initiation of the tachycardia and how to prevent it are discussed in this article.
BACKGROUND: Potentially malignant coronary artery anomalies (CAAs) are single coronary artery, myocardial bridges with deep course, ALCAPA, large or multiple fistulas, and anomalous coronary artery from the opposite sinu...BACKGROUND: Potentially malignant coronary artery anomalies (CAAs) are single coronary artery, myocardial bridges with deep course, ALCAPA, large or multiple fistulas, and anomalous coronary artery from the opposite sinus, interarterial course (IAC) anomalies, which can lead to life-threatening complications. It is well-known that the early repolarization pattern (ERP) is associated with sudden cardiac death (SCD).This investigation aimed to assess the relationship between ERP and poor cardiac outcomes in patients with malignant CAAs. METHODS: Imaging findings, electrocardiographic features, clinical details, and long-term outcomes were retrospectively assessed. The primary outcome was measured as major adverse cardiac events (MACE), defined as a combination of fatal ventricular arrhythmias (VAs), syncope, or SCD. The secondary endpoint was described as a combination of fatal VAs or SCD.The study population was divided into 2 groups: MACE (+) and MACE (-). RESULTS: A total of 139 patients with malignant CAAs [mean age: 54.54 ± 12.46 years; male:73 (52.5%)] were included in this study.At least one MACE occurred in 16 (11.5%) patients during follow-up. The frequencies of IAC anomalies (68.8 vs 39.0%, p = 0.024) and ERP (50 vs 14.6%, p = 0.002) were notably higher in the MACE (+) group than the others.The penalized Cox regression analysis demonstrated that ERP (HR = 4.06, 95%CI: 1.44-11.44, p = 0.008 for MACE, and HR = 6.45, 95%CI: 1.56-26.66, p = 0.008 for SCD or fatal VAs) was found to be an independent predictor of primary and secondary endpoints. CONCLUSION: The present study suggests that ERP may be associated with poor outcomes; however, causality cannot be inferred due to the retrospective observational design.
AIMS: We aimed to systematically evaluate standard 12‑lead electrocardiograms (ECG) in young individuals with exercise-induced laryngeal obstruction (EILO), with a special focus on the prevalence and clinical significanc...AIMS: We aimed to systematically evaluate standard 12‑lead electrocardiograms (ECG) in young individuals with exercise-induced laryngeal obstruction (EILO), with a special focus on the prevalence and clinical significance of T-wave inversion (TWI). METHODS AND RESULTS: 235 individuals (mean age 16.7 years, 85% females) presenting to the EILO Clinic, underwent 709 high-intensity cardiopulmonary exercise treadmill testing with continuous visualization of the larynx (CLE- Continuous Laryngoscopy Exercise). There was no adverse event during exercise tests. The prevalence of TWI (negatively deflected T-wave ≥1 mm (0.1 mV amplitude) in any 2 contiguous leads excluding aVR, III, and V1) was 42.6% (18.7% isolated in the inferior wall leads, 13.2% in the inferolateral leads, 5.1% in both the inferior and anterior leads, 3% both in the inferior and anteroseptal leads, 2.1% isolated in anteroseptal leads and 0.9% isolated in anterior wall leads). Age, body height and weight, exercise duration and peak oxygen uptake did not differ between individuals with versus without TWI (all p > 0.05). There was a trend towards lower total CLE score in individuals with TWI (4.2 vs 4.5, p = 0.070). Individuals with TWI had higher resting heart rate (98 vs 95 bpm, p = 0.05), shorter PQ-interval (124 vs 129 ms, p = 0.020) and achieved higher peak heart rate (193 vs 189 bpm, p = 0.005) and metabolic equivalents during exercise (13.4 vs 12.9, p = 0.028). CONCLUSIONS: High-intensity CLE-test in individuals with EILO was not associated with any adverse cardiac findings. TWI was highly prevalent and particularly observed in the inferior or inferolateral wall leads but had no association with energetic decline or cardiac dysfunction.
We report a 62-year-old woman with a long history of palpitations who presented with fatigue and acute dyspnea. ECG demonstrated a regular narrow-QRS tachycardia with long RP' intervals and 1:1 atrioventricular conductio...We report a 62-year-old woman with a long history of palpitations who presented with fatigue and acute dyspnea. ECG demonstrated a regular narrow-QRS tachycardia with long RP' intervals and 1:1 atrioventricular conduction. Episodes were recurrent despite amiodarone and beta-blockers, and transthoracic echocardiography revealed severe biventricular dysfunction which improved after rhythm control. We discuss the ECG features, mechanisms, and diagnostic clues of long RP' supraventricular tachycardia in adults.
A 62-year-old man presented with severe chest pain and hypotension. The ECG demonstrated deep ST-depression in leads V-V, fused with QRS complex and T wave, resembling an inverted "shark fin" pattern. We discuss the clin...A 62-year-old man presented with severe chest pain and hypotension. The ECG demonstrated deep ST-depression in leads V-V, fused with QRS complex and T wave, resembling an inverted "shark fin" pattern. We discuss the clinical significance of this unusual ECG pattern.
Current guidelines classify acute coronary syndrome (ACS) into unstable angina (UA), ST-segment elevation myocardial infarction (STEMI), and non-ST-segment elevation myocardial infarction (NSTEMI). However, this classifi...Current guidelines classify acute coronary syndrome (ACS) into unstable angina (UA), ST-segment elevation myocardial infarction (STEMI), and non-ST-segment elevation myocardial infarction (NSTEMI). However, this classification pattern may lead to inadequate recognition of acute coronary occlusion (ACO), particularly when electrocardiographic (ECG) findings are atypical. An increasing number of "STEMI-equivalent" ECG patterns are considered significant features of ACO. The Aslanger's pattern is regarded as indicative of right coronary artery (RCA)-related inferior wall myocardial infarction, while the de Winter's pattern is considered an STEMI-equivalent manifestation of acute left anterior descending (LAD) occlusion. This article reports two cases of ACS patients who exhibited both Aslanger's and de Winter's patterns on admission ECG, but coronary angiography confirmed acute lesions in the left coronary artery system. The Aslanger's pattern is not a specific manifestation of RCA lesions. When co-occurring with de Winter patterns, heightened vigilance for acute left coronary artery lesions is warranted. Identifying such patterns holds significant clinical importance for avoiding delays in reperfusion therapy.
BACKGROUND: ST-segment elevation myocardial infarction (STEMI) and its equivalents describe the electrocardiogram (ECG) findings of acute coronary occlusion myocardial infarction (OMI). Discordance in ECG interpretation...BACKGROUND: ST-segment elevation myocardial infarction (STEMI) and its equivalents describe the electrocardiogram (ECG) findings of acute coronary occlusion myocardial infarction (OMI). Discordance in ECG interpretation between Emergency Medicine and Cardiology teams is common. OBJECTIVES: We examined the utility of an artificial intelligence (AI) algorithm to improve diagnostic accuracy for OMI in the difficult subset of canceled STEMI activations. METHODS: We conducted a retrospective review of STEMI activations over 17 months. We included cases that were canceled with the rationale of "ECG not meeting STEMI criteria." We excluded sustained activations, cancellations with alternative rationales, and incomplete records. OMI was defined as an angiographic culprit lesion with TIMI 0 or 1 flow. ECGs were reviewed by the AI algorithm and assessed for STEMI criteria. RESULTS: Of 1224 STEMI activations, 185 cancellations (15.1%) were included, with 17 patients meeting the study definition of OMI. STEMI criteria demonstrated lower sensitivity for OMI as compared to the AI algorithm (47.1% vs 94.1%, p = 0.005), and a non-significantly lower specificity (66.1% vs 73.2%, p = 0.090). The AI algorithm also demonstrated higher positive and negative likelihood ratios for OMI identification (3.51 and 0.08, respectively) than STEMI criteria (1.39 and 0.80, respectively). CONCLUSIONS: Our data suggests that the AI algorithm may serve as a clinical adjunct to improve interrater reliability between Emergency Medicine and Cardiology teams in OMI identification. Further prospective studies may help evaluate its utility in clinical practice.
BACKGROUND: Fragmented QRS (fQRS) complexes have been associated with myocardial conduction abnormalities and arrhythmic risk in various cardiac conditions. However, their clinical significance in patients with isolated...BACKGROUND: Fragmented QRS (fQRS) complexes have been associated with myocardial conduction abnormalities and arrhythmic risk in various cardiac conditions. However, their clinical significance in patients with isolated hypertension, particularly in relation to ventricular arrhythmia burden and autonomic dysfunction, remains incompletely understood. This study aimed to investigate the association between fQRS, ventricular arrhythmia burden, left ventricular geometry, and cardiac autonomic function in these patients. METHODS: This retrospective observational study included 229 patients with isolated hypertension who underwent 24-h rhythm Holter monitoring and ambulatory blood pressure monitoring. Patients were classified according to the presence of fQRS on standard 12‑lead electrocardiography. Ventricular arrhythmias were evaluated using Holter recordings and classified according to the Lown classification system. Cardiac autonomic function was assessed using heart rate variability (HRV) and heart rate turbulence (HRT) parameters. Echocardiographic evaluation was performed to assess left ventricular mass and geometry. Comparisons were made between patients with and without fQRS, and multivariable logistic regression analysis was used to identify independent predictors of higher arrhythmia burden. RESULTS: fQRS was present in 101 patients (44.1%) who demonstrated significantly higher ventricular and atrial ectopic burden and were more frequently classified into higher Lown arrhythmia classes compared with those without fQRS (p < 0.001). Echocardiographic assessment revealed greater left ventricular mass index and a higher prevalence of concentric hypertrophy in patients with fQRS. Standard HRV parameters (SDNN and RMSSD) as well as the variability index (%), were significantly lower in the fQRS group, and impaired HRT was observed exclusively among these patients. Non-dipper heart rate pattern was also significantly more frequent in patients with fQRS. In multivariable analysis, lower SDNN values, the presence of fQRS, concentric hypertrophy, and non-dipper heart rate pattern emerged as independent predictors of higher Lown classification. CONCLUSIONS: In patients with isolated hypertension, fQRS is associated with increased ventricular arrhythmia burden, adverse left ventricular remodeling, and objective markers of autonomic dysfunction.
A 34-year-old female patient presented with typical junctional premature beats (JPB), along with beats mimicking blocked atrial premature beats (APB) and ventricular premature beats (VPB). In accordance with the principl...A 34-year-old female patient presented with typical junctional premature beats (JPB), along with beats mimicking blocked atrial premature beats (APB) and ventricular premature beats (VPB). In accordance with the principle of monism, these premature beats with similar coupling intervals but markedly different morphologies should be regarded as diverse manifestations of JPB. Such electrocardiographic (ECG) findings are highly deceptive and prone to misdiagnosis.
A 60-year-old male with a single-chamber AAI pacemaker implanted for symptomatic sinus node dysfunction presented for routine follow-up. ECG showed an alternating pattern of atrial sensed (As) and atrial paced (Ap) beats...A 60-year-old male with a single-chamber AAI pacemaker implanted for symptomatic sinus node dysfunction presented for routine follow-up. ECG showed an alternating pattern of atrial sensed (As) and atrial paced (Ap) beats. Analysis demonstrated a shorter As-Ap interval (1000 ms) compared to a prolonged Ap-As interval (∼1200 ms), inconsistent with hysteresis. The delayed atrial pacing suggested oversensing. Further evaluation identified far-field R-wave sensing following atrial paced beats, which reset the lower rate interval, leading to suppression of timely atrial pacing. This phenomenon occurred selectively after paced beats because the subsequent QRS complex fell outside the atrial refractory period, unlike after sensed beats. Device interrogation confirmed far-field R-wave oversensing and a longer AV interval following paced events. Management included prolongation of the atrial refractory period and adjustment of the lower rate interval, which resolved the alternating pacing pattern. This case highlights the importance of recognizing far-field R-wave oversensing as a cause of atypical pacing behavior and underscores the need for a thorough understanding of pacemaker timing cycles.