Repolarization Abnormalities Research Articles

Distinguishing Wolff-Parkinson-White Syndrome From Fasciculoventricular Pathway Using QRS-T Angle Analysis.

Wolff-Parkinson-White (WPW) syndrome and fasciculoventricular pathway (FVP) present electrocardiographic manifestations characterized by delta waves, differentiating these two is challenging. Specifically, WPW type B with QRS width ≤120ms, resembles typical FVP features. Because of the presence of repolarization abnormalities in WPW syndrome, our hypothesis centered on the potential utility of the QRS-T angle for distinguishing WPW syndrome from FVP. To determine the discriminative value of the QRS-T angle for delineating WPW syndrome from FVP. We included cases of WPW syndrome treated with catheter ablation and FVP diagnosed via adenosine triphosphate administration between 2007 and 2023. We excluded cases with WPW type A, QRS width >120ms, intermittent WPW, congenital heart disease or myocardial damage, ablation history, tachycardia, palpitations within 3 months, and WPW syndrome featuring an accessory pathway on the left lateral wall. Eventually, we identified 40 and 54 patients from the WPW and FVP groups, respectively. The QRS-T angle was compared between the WPW and FVP cohorts. The QRS-T angle in the WPW group was significantly larger than in the FVP group (45.7 ± 46.3° vs. 17.8 ± 13.9°, p < 0.001). Receiver operating characteristic curve analysis with a sensitivity and specificity of 65.0% and 72.6%, respectively, demonstrated that the optimal cut-off value for the QRS-T angle was 22° for distinguishing WPW from FVP. Remarkably, all cases with a QRS-T angle >65° were within the WPW group. The QRS-T angle can offer promising utility in differentiating WPW syndrome from FVP.

Abstract 4134560: Sex Differences in Repolarization Abnormalities Associated with Ventricular Arrhythmia in Mitral Valve Prolapse

Background: Compared to men, women with mitral valve prolapse (MVP) are more likely to present with sudden death, and most women who die suddenly are premenopausal. Repolarization abnormalities are common in patients with MVP-attributed sudden death. However, differences in repolarization between men and women with MVP are not known. Hypothesis: Repolarization abnormalities are associated with ventricular arrhythmia and are more common in women than men with MVP. Aims: To investigate associations of ECG repolarization abnormalities with sex and ventricular arrhythmia in MVP. Methods: We reviewed 12-lead ECGs from 272 adults with MVP for T-wave inversion, ST segment elevation, ST depression, QTc and QT dispersion. Patients were excluded if they had prior MI, coronary artery disease, mitral valve surgery, moderate or severe LVH, heart failure, reduced left ventricular ejection fraction, atrial fibrillation or QRS duration &gt;120ms. Transthoracic echocardiograms were reviewed for mitral regurgitation, mitral annular disjunction, bi-leaflet or myxomatous MVP. Ambulatory ECGs (n=94) were assessed for NSVT or PVCs (&gt; 1% burden) and ECGs for &gt;1 PVC on any 10 second tracing. Associations were evaluated using Fisher’s exact test, Wilcoxon rank-sum test or multiple linear regression. Results: Among 272 patients, median (IQR) age was 58 (47-67) years, 162 (59.6%) were women, 46 (16.9%) were African American, and 34 (12.5%) had frequent ventricular ectopy. Women and men had similar rates of NSVT (15/66 [22.7%] vs 4/28 [14.3%], p=0.41) and frequent ventricular ectopy (25/162 [15.4%] vs 9/110 [8.1%], p=0.093). The QTc was longer in women (433 [417, 446] vs 423 [406, 442] ms, p=0.023) and in those with NSVT (437 [421, 444] vs 421 [405, 436] ms, p=0.028), but not in those with ventricular ectopy (437 [420, 445] vs 428 [410, 444] ms, p=0.15). There was a trend towards increased QTc in patients with mitral annular disjunction (433 [418, 454] vs 429 [408, 444] ms, p=0.054) and myxomatous MVP (434 [414, 450] vs 427 [408, 444] ms, p=0.076). Female sex was the only independent predictor of QTc (R 2 =0.14, p=0.0032). Conclusion: Among patients with mitral valve prolapse, women have longer QT interval than men, and longer QT interval is associated with nonsustained ventricular tachycardia. Subtle or dynamic delay in repolarization may promote malignant ventricular arrhythmias in women. Understanding these relationships may help identify patients at risk for sudden death.

Abstract 4145896: Terminal Rhythm of the Worldwide First Genetically Modified Porcine-to-Human Xenotransplantation

Background: The worldwide first genetically modified porcine-to-human cardiac xenotransplantation was successfully performed in January 2022 at the University of Maryland with the recipient surviving 60 days. Aim: Assess the ECG parameters and cardiac rhythm during the death of the worldwide first porcine-to-human xenotransplant. Methods: Continuous 6-lead ECG telemetry was used to analyze ECG parameters and cardiac rhythm during the final 9 minutes after withdrawal of life support. Results: At the time of withdrawal (W), the patient was in sinus rhythm (70bpm, PR interval 280ms, right bundle branch block (RBBB) with QRS 140ms, QT 400ms; Figure). PR prolongation up to 360ms with loss of P wave was noted at W+2:55min. Irregular junctional rhythm with blocked PACs and bradycardia (23 bpm) occurred around W+3:25min. At that time, widening of RBBB to 160ms with non-specific repolarization abnormalities and QT prolongation were observed. At W+4:30min, increasing pauses of up to 8.5s with mild QRS axis shift occurred. At W+6min, asystole (up to 20s) with rare PVCs from the left anterolateral LV base were seen. Final rhythm at W+6min consisted of ventricular escape beats from the infero-basal LV before electrical activity ceased at W+6:45min. No other atrial or ventricular arrhythmias were noted. Conclusion: The porcine-to-human cardiac xenotransplant showed a terminal rhythm of bradycardia, sinus arrest, and junctional and ventricular escape beats. This is consistent with ischemia-related failure of impulse generation, slowing intra-atrial/AV-conduction delay, and failure of impulse propagation. Notably, no tachyarrhythmias were seen despite ectopic atrial and ventricular beats with prolongation of depolarization and repolarization. This is similar to traditional terminal rhythms observed in humans and does not suggest unexpected arrhythmic proclivities between pig myocardium and the human environment (“pig heart in human body”).

High-density isochronal repolarization mapping and re-entry vulnerability estimation for scar-related ventricular tachycardia ablation: mechanistic basis, clinical application, and challenges.

Alterations in repolarization gradients and increased heterogeneity are key electrophysiological determinants of ventricular arrhythmogenesis across a variety of aetiologies with and without structural heart disease. High-density repolarization mapping to localize these repolarization abnormalities could improve characterization of the individual arrhythmogenic substrate and inform more targeted ablation. Yet, due to challenges posed by intrinsic features of human cardiac repolarization itself as well as technical and practical limitations, they are not routinely assessed, and traditional substrate mapping techniques remain strictly limited to determining conduction abnormalities. Here, we provide an overview of the mechanistic role of repolarization alterations in ventricular re-entry arrhythmias followed by a description of a clinical workflow that enables high-density repolarization mapping during ventricular tachycardia (VT) ablations using existing clinical tools. We describe step-by-step guidance of how-to set-up and generate repolarization maps illustrating the approach in case examples of structural normal and abnormal hearts. Furthermore, we discuss how repolarization mapping could be combined with existing substrate mapping approaches, including isochronal late activation mapping, to delineate sites of increased re-entry vulnerability, that may represent targets for ablation without the requirement for VT induction. Finally, we review challenges and pitfalls and ongoing controversies in relation to repolarization mapping and discuss the need for future technical and analytical improvements in repolarization mapping to integrate into ventricular substrate mapping strategies. Repolarization mapping remains investigational, and future research efforts need to be focused on prospective trials to establish the additional diagnostic value and its role in clinical ablation procedures.

Clinical and genetic profiles of patients with hereditary and wild type transthyretin amyloidosis: the transthyretin cardiac amyloidosis registry in the state of Sao Paulo, Brazil REACT-SP

Abstract Introduction Transthyretin amyloidosis (ATTR) is a multisystem disease caused by the deposition of fibrillar protein in organs and tissues. ATTR genotypes and phenotypes are highly heterogeneous. Purpose We designed the Transthyretin Cardiac Amyloidosis Registry in the state of São Paulo (REACT-SP), aiming to describe the demographic, genetic, clinical, and diagnostic test results and treatment of patients with ATTR. Methods We present data on physical signs and symptoms, cardiac and neurological assessments, and genetics in patients enrolled in the Transthyretin Cardiac Amyloidosis Registry in the state of São Paulo, Brazil. Results Six hundred-forty-four patients were enrolled, 505 with the variant form (ATTRv) and 139 with wild-type (ATTRwt). Sixteen different mutations were detected, the most common being Val50Met (48.3%) and V142Ile (40.8%). Overall, more than half of the patients presented cardiological involvement, and the difference in this proportion between the ATTRv and ATTRwt groups was significant (43.9 vs. 89.9%; p&amp;lt;0.001). The neurological phenotype also differed between ATTRv and ATTRwt (56.8 vs. 31.7%; p&amp;lt;0.001). The mixed phenotype was found in 25.6% of the population, without a significant difference between the forms of amyloidosis. A group of patients remained asymptomatic (10.4%), with a lower proportion of asymptomatic ATTRwt patients. The median time between the onset of symptoms and diagnosis was 1,853 (IQR 1277–2997) days, which was longer in ATTRv patients than in ATTRwt patients (p&amp;lt;0.001). Sinus rhythm was reported in 74.2%, atrial fibrillation in 17.0%, low voltage in 28.6%, repolarization abnormalities in 39.8%, and pseudo infarction in 27.4%. Echocardiography showed median Left Ventricular Ejection Fraction (LVEF) was 60%, Interventricular Septum (IVS) 14 mm, Posterior Wall Thickness (PWT) 13 mm, Left Atrium (LA) 41 mm, Left Ventricular Diastolic Diameter (LVDD) 45 mm, Left Ventricular Systolic Diameter (LVSD) 30 mm, basal Right Ventricular Diastolic Diameter (RVDD) 35 mm and Left Ventricle (LV) longitudinal strain 9.1%. There was some degree of LV diastolic dysfunction in 38.4%, apical sparing in 31.3%, and thrombus or masses in 1.0%. Late Gadolinium Enhancement (LGE) was absent in 29% and was subendocardial in 35.5%, transmural in 13.7%, mesocardial in 13.7%, and epicardial in 8.2%. Conclusions This study details the clinical and genetic spectrum of patients with ATTR in São Paulo, Brazil. This preliminary analysis highlights the considerable phenotypic heterogeneity of neurological and cardiac manifestations in patients with variant and wild-type ATTR.

The spectrum of ECG abnormalities in a large cohort of histologically proven cardiac tumors

Abstract Background Cardiac tumors represent a heterogeneous clinical scenario. The role of ECG in the diagnostic work-up remains to be investigated. Objectives To describe the spectrum of electrocardiographic abnormalities in a large cohort of histologically proven cardiac tumors and to evaluate potential red flags of malignancy. Material and Methods 247 consecutive patients with histologically proven cardiac tumors and available ECG at Bologna University Hospital were enrolled. All ECGs were independently analyzed off-line using a manual caliper by two experienced cardiologists who were blinded to clinical information and histological results. In case of disagreements, a third consensus re-assessment was performed to resolve any discrepancies. Multivariable regression analysis was used to assess potential predictors of malignancy among electrocardiographic abnormalities. Results Of 247 patients, 98 (39.7%) had malignant tumors. Compared with patients with benign tumors, those with malignant tumors exhibited a higher heart rate, right axis deviation, greater depolarization, repolarization abnormalities and bradyarrhythmia at presentation. Regarding specific ECG features, a higher heart rate on admission (p=0.001), bradyarrhythmias (p=0.01), ischemic-like repolarization abnormalities (ST-segment deviation, both depression and elevation, and negative T-wave; p&amp;lt;0.001) and low voltages (p=0.005) were identified as independent predictors of malignancy. Conclusion ECG is frequently abnormal in case of malignant cardiac tumors. Some specific electrocardiographic changes could have a supportive role in the diagnostic workup of patients with cardiac tumors by increasing the clinical suspicion of malignancy.ECG Tumors

Magnetocardiographic imaging of Tpeak-Tend magnetic field dynamics discriminates between ventricular repolarization disorders due to mitral valve prolapse and to ischemic heart disease

Abstract Background Several etiopathogenetic mechanisms, including ischemia of the papillary muscles, abnormal catecholamine regulation, baroreflex modulation, and activation of atrial natriuretic peptide induced by abnormal stretch of the prolapsing mitral leaflets, have been suggested as possible causes of ventricular repolarization abnormalities (VRab) in patients (pts) with mitral valve prolapse (MVP) [1-3], especially in those with chest pain (CP). Purpose Since magnetocardiography (MCG) is a sensitive alternative to improve the detection of VRab, this study aimed to evaluate its discrimination accuracy to differentiate VRab due to MVP from those due to ischemic heart disease (IHD). Methods MCG recordings of 32 female patients (age 40.3±13.3 years) with MVP (at echocardiography), 20 of them with CP and/or palpitations, were retrospectively compared with those of 35 pts with IHD (at least one vessel stenosis &amp;gt;70%) (age 66.2±10.6 years), and with those of 32 age-matched (age 40.8±11.5 years) healthy females (HF) without MVP. The cardiac magnetic field (MF) component perpendicular to the anterior chest wall (Bz) was recorded with a 36-channel DC-SQUID MCG system (sensitivity ~30 fT/VHz). Thirteen MCG parameters, five derived from the analysis of the T-wave MF extrema dynamics, and eight from the effective magnetic vector (EMV) dynamics, were automatically calculated with proprietary software during the Tpeak-Tend interval (T3-T4 in Figure 1). Discriminant analysis (DA) was applied to separate groups. Results At univariate analysis, 11 MCG parameters were significantly different (p&amp;lt; 0.05) between MVP and IHD pts (Table 1). After multivariate analysis, 9 parameters (AzimuthMeanA, TrajectoryLengthRangeD, AngleDerivativeRangeD, AzimuthdiffAD, Q2AnalysisScore, AngleMinimum, AngleDynamics, DistanceDynamics, RatioDynamics) differentiated MVP and IHD pts’ VRab with 80% accuracy (cross-correlated), at DA. Moreover, in IHD pts abnormality of EMV dynamics extended also along the whole T-wave [4]. Three EMV parameters of the Tpeak-Tend interval (TrajectoryLengthRangeD, AzimuthdiffAD, Q2AnalysisScore), and three T-wave MF extrema parameters (AngleMinimum, Distance Dynamics, and Ratio Dynamics) were abnormal in 11 MVP pts, 10 of them with CP but normal ECG, and only one asymptomatic. Discussion: MCG EMV and MF dynamics calculated from rest-MCG data are reliable to identify VRab in pts with MVP and with IHD, differentiating them with a good discrimination accuracy. MCG VRa abnormality was mostly confined in the Tpeak-Tend interval in pts with MVP (in agreement with previous ECG findings [5]), while extended to the whole ST interval in IHD pts. Rest MCG is more sensitive than ECG in detecting VRab in pts with MVP and CP. Due to the limited number of investigated cases, the potential arrhythmogenicity of MVP-related VRab detected with MCG was not evaluated.Figure 1.MCG imaging of Tpeak-Tend MFTable 1

QRS prolongation is associated with associated with adverse cardiac remodeling in hypertrophic cardiomyopathy

BackgroundSignal-averaged electrocardiogram (SAECG) records myocardial depolarization, and can detect inhomogeneous/slow conduction in fibrotic myocardium, which promotes reentrant ventricular arrhythmias (VAs). Hypertrophic cardiomyopathy (HCM) is associated with a high prevalence of cardiac fibrosis and VAs, but abnormal SAECG has low predictive power for VAs. We hypothesized that HCM-specific structural/electrical remodeling underlies this result. MethodsWe tested our hypothesis by retrospectively studying HCM patients (n = 73) who underwent transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) imaging within 12 months of SAECG and 12‑lead ECG. Patients were divided into 2 groups (normal-SAECG, abnormal-SAECG) based on filtered-QRS duration (fQRSd), root-mean-square-voltage (RMS40) and low-amplitude (<40 μV) signal of terminal 40 ms of filtered-QRS (late potentials). Abnormal SAECG was defined as fQRSd > 114 ms, RMS40 < 20 μV or LAS40 > 38 ms. ResultsAbnormal SAECG was seen in ∼50 % of HCM patients (37/73). In the abnormal-SAECG group, 78 % (n = 29) only had prolonged fQRSd, and 22 % (n = 8) had prolonged fQRSd plus late potentials (RMS40 < 20 μV or LAS40 > 38 ms). Mean fQRSd and LAS40 were significantly higher in the abnormal-SAECG group. The abnormal-SAECG group had significantly larger LA size, lower global-LV longitudinal systolic strain/strain rate and early-diastolic strain rate by TTE; higher LV-mass index (LVMI) and LV-scar burden by CMR; higher prevalence of repolarization abnormalities on 12‑lead ECG. LVEF and adverse outcomes (VT/VF, heart failure, death) were similar in the 2 groups. Univariate analysis showed that fQRSd is positively correlated with LVMI, LV-scar mass, and negatively correlated with global-LV early diastolic strain rate. ConclusionsIn HCM, abnormal SAECG is associated with greater structural/electrical LV-remodeling, reflecting a severe global myopathy.

Electrocardiographic abnormalities are frequently detected in healthy adult Borzoi with a normal echocardiogram.

Borzoi reportedly experience sudden death. The objective of this study was to report ECG intervals, amplitudes, and frequency of ECG abnormalities in clinically healthy Borzoi. 98 clinically healthy Borzoi were prospectively recruited and underwent echocardiogram, ECG, and cardiac troponin I testing between October 2020 and December 2022. Standard ECG measurements were obtained. Early repolarization notches and slurs were recorded. Of 82 Borzoi with a structurally normal echocardiogram, ventricular arrhythmias were documented in 8 (10%) dogs, all of which had normal cardiac troponin I concentrations. Median P wave duration was 55 milliseconds (range, 45 to 70 milliseconds). Median PR interval was 125 milliseconds (range, 80 to 175 milliseconds). Thirty-one (38%) Borzoi had first-degree atrioventricular block (PR interval > 130 milliseconds). Median QRS duration was 65 milliseconds (range, 48 to 90 milliseconds). Median QT interval was 235 milliseconds (range, 185 to 275 milliseconds). Twenty-nine (35%) and 15 (18%) of 82 Borzoi had QT intervals > 240 or > 250 milliseconds, respectively. Sixty-seven of 82 (82%) Borzoi had early repolarization notches or slurs. Seventeen of 82 (21%) Borzoi had an abnormality of the ST segment, most commonly convexity/doming. Convexity of the ST segment was intermittent (n = 9) or persistent (4). Ventricular arrhythmias, early repolarization, prolonged QT intervals, and ST segment abnormalities are not infrequent in clinically healthy Borzoi. P, PR, and QRS durations are commonly prolonged compared to general canine reference intervals. Future study into heritable channelopathies in Borzoi is warranted given the frequency of ventricular arrhythmias, repolarization abnormalities, and sudden death in the breed. Breed-specific ECG reference intervals are needed.

Association of Electrocardiogram Findings With Clinical Outcomes in Patients With Chronic Coronary Syndrome: An Analysis of the ISCHEMIA Trials

ObjectiveWe aimed to investigate the association of electrocardiogram (ECG) findings with outcomes in patients with chronic coronary syndrome. MethodsThis secondary analysis of the ISCHEMIA and ISCHEMIA-CKD trials divided patients with chronic coronary syndrome into two groups, those with a normal ECG tracing and abnormal ECG tracing. Repolarization abnormalities included ST-segment depression ≥ 0.5 mm and T-wave inversion ≥ 1 mm; conduction abnormalities included left and right bundle branch block (LBBB and RBBB). The primary endpoint was cardiovascular death. Outcomes were assessed using a covariate-adjusted Cox-regression model. ResultsOf 5876 patients, 2901 (49.4%) had a normal and 2975 (50.6%) an abnormal ECG tracing. An abnormal ECG tracing at baseline, compared with a normal ECG tracing, was associated with an increased risk of cardiovascular death (257 of 2975 [8.6%] vs. 97 of 2901 [3.3%], adjusted hazard ratio [aHR] 2.01, 95% CI 1.58-2.55) over a median follow-up period of 3.1 years (IQR 2.1-4.2). This finding was consistent across subgroups except for patients with black skin color and current smokers, in whom an abnormal ECG was not significantly associated with increased risk of cardiovascular death. Individual ECG abnormalities (ST-segment depression [aHR 2.0, 95% CI 1.52-2.63], T-wave inversion [aHR 1.89, 95% CI 1.40-2.54], LBBB [aHR 1.74, 95% CI 1.05-2.90], and RBBB [aHR 1.52, 95% CI 1.04-2.22]) were independently associated with an increased risk of cardiovascular death. ConclusionIn patients with chronic coronary syndrome, an abnormal ECG tracing was associated with an increased risk of cardiovascular death. Our findings underscore the importance of the ECG in cardiovascular risk stratification and prognostication. Trial RegistrationNCT01471522, BioLINCC ID 14539.

Prognostic value of the electrocardiogram in patients with bicuspid aortic valve disease

BackgroundIdentifying bicuspid aortic valve (BAV) patients at risk for cardiac events remains challenging and the role of the electrocardiogram (ECG) has not yet been described. Therefore, this study aims to describe ECG parameters in BAV patients, and investigate their prognostic value. MethodsIn this single-center prospective study patients with BAV without a prior aortic valve replacement (AVR) were included. Transthoracic echocardiogram and 12‑lead resting-ECG were obtained. Associations between ECG parameters and the composite endpoint of all-cause mortality and AVR were assessed using Cox-proportional hazard analysis. Results120 patients with BAV were included (median age 30 years, 61% male). Median aortic jet velocity was 2.4 m/s [IQR: 1.7–3.4] and 5 patients (4%) had severe aortic regurgitation. All patients were in sinus rhythm. Any ECG abnormality was present in 57 patients (48%). Median PR-interval was 156 [IQR: 138–170] msec. A deviating QRS axis was found in 17 patients (14%) and Cornell criteria for LVH were fulfilled in 20 patients (17%). Repolarization abnormalities were present in 12 patients (10%). Median follow-up duration was 7.0 [6.3–9.8] years, during which 23 patients underwent AVR and 2 patients died. After adjusting for age, a longer PR-interval was associated with worse intervention-free survival (HR 1.02, 95% CI: 1.01–1.04). ConclusionAlmost half of the patients with BAV had abnormalities on their ECG. Moreover, the PR-interval may be an interesting prognostic marker for intervention-free survival in BAV patients.

Dysregulation of N-terminal acetylation causes cardiac arrhythmia and cardiomyopathy.

N-terminal-acetyltransferases including NAA10 catalyze N-terminal acetylation (Nt-acetylation), an evolutionarily conserved co-translational modification. Little is known about the role of Nt-acetylation in cardiac homeostasis. To gain insights, we studied a novel NAA10 variant (p.R4S) segregating with QT-prolongation, cardiomyopathy and developmental delay in a large kindred. Here we show that the NAA10-R4S mutation reduced enzymatic activity, decreased expression levels of NAA10/NAA15 proteins, and destabilized the enzymatic complex NatA. In NAA10R4S/Y-iPSC-CMs, dysregulation of the late sodium and slow rectifying potassium currents caused severe repolarization abnormalities, consistent with clinical QT prolongation. Engineered heart tissues generated from NAA10R4S/Y-iPSC-CMs had significantly decreased contractile force and sarcomeric disorganization, consistent with the pedigree's cardiomyopathic phenotype. We identified small molecule and genetic therapies that normalized the phenotype of NAA10R4S/Y-iPSC-CMs. Our study defines novel roles of Nt-acetylation in cardiac regulation and delineates mechanisms underlying QT prolongation, arrhythmia, and cardiomyopathy caused by NAA10 dysfunction.

Arrhythmic Mitral Valve Prolapse Syndrome and Ventricular Arrhythmias: A Comprehensive Review and the Role of Catheter Ablation.

Mitral valve prolapse (MVP) affects 2-3% of the general population, and despite its benign prognosis overall, it is associated with sudden death in a small subset of patients. The term "arrhythmic MVP syndrome" (AMVPS) refers to the presence of frequent or complex ventricular arrhythmias, commonly reported in female patients with a stereotypical phenotype including bileaflet myxomatous disease, ECG repolarisation abnormalities in inferior leads, mitral annular disjunction, and significant fibrosis in the inferolateral LV and papillary muscles. Modern imaging technologies have led to the identification of new risk factors that have been implemented in recent risk stratification guidelines; however, screening for patients with MVP who are at risk of sudden cardiac death (SCD) remains challenging. In addition, there is a limited amount of data on the outcomes of different treatment approaches in AMVP and no specific indication for targeted or disease-modifying therapies within current guidelines. Potential arrhythmic substrates in patients with AMVP syndrome have been the subject of interest in previous studies, with areas consisting of fibrosis at the papillary muscle level and the Purkinje system. Premature ventricular contractions (PVCs) originating from these areas have been shown to play an important role as triggers for ventricular fibrillation and SCD in patients with AMVP. Catheter ablation has emerged as a potential treatment modality in patients with MVP and ventricular arrhythmias (VAs), targeting arrhythmic substrates and triggering PVC foci. The aim of this review is to explore the role of catheter ablation in treating patients with AMVP.

Congenital Apical Left Ventricular Aneurysm.

A 17-year-old male was referred for evaluation by Pediatric Cardiology following a pre-sports medical screening, which revealed abnormal ventricular repolarization (negative T wave from V3-V6) on a 12-lead ECG. For 8 years, he has been a competitive football player. There was no relevant personal or family medical history, and he denied any prior cardiovascular symptoms. His cardiovascular physical examination was normal. In the initial assessment, a transthoracic echocardiogram was conducted, revealing an apical aneurysm of the left ventricle (LV) with regional dyskinesia, accompanied by mild mitral regurgitation. The examination also demonstrated globally preserved left ventricular systolic function, with no images suggestive of vegetations or intracardiac thrombi found. For further anatomical and myocardial characterization, a cardiac magnetic resonance (CMR) was performed. The results revealed a wide apical aneurysm of the LV, predominantly lateral, with thin walls, ridges within the outpouching, and local dyskinesia. No areas of late gadolinium enhancement (LGE) were found, suggestive of fibrosis, anomalous infiltration, or scar from a previous infarction. After excluding other etiologies, the diagnosis of a congenital ventricular aneurysm was determined. This is a very rare condition (0.12%) with a wide and variable clinical presentation, ranging from benign arrhythmias to sudden death. Various imaging techniques aid in its diagnosis, with CMR being particularly useful for excluding inflammation and cardiomyopathies, identifying LGE, and evaluating left ventricular volumes and function. There is no standard treatment, and controversy surrounds indications for surgical intervention. If a conservative approach is adopted, measures aimed at preventing endocarditis and embolism must be considered.

"Spasms in Silence": A case of coronary vasospasm-induced ventricular fibrillation.

A 56-year-old man presented following an aborted cardiac arrest. His initial ECGs showed episodes of transient repolarization abnormalities. Coronary vasospasm can be a precipitant for ventricular arrhythmia in these patients, underpinning the importance of continuous ECG for accurate diagnosis and management.

Spectrum of electrocardiographic abnormalities in a large cohort of cardiac masses

BackgroundCardiac masses represent a heterogeneous clinical scenario. Potential electrocardiographic (ECG) red flags of malignancy remain to be investigated. ObjectivesThe purpose of this study was to describe the spectrum of ECG abnormalities in a large cohort of cardiac masses and to evaluate potential red flags suggestive of malignancy. MethodsThis was an observational cohort study of 322 consecutive patients with a cardiac mass and available ECG at Bologna University Hospital. All masses were diagnosed by histologic examination or, in the case of cardiac thrombi, by radiologic resolution after proper anticoagulant therapy. Multivariable regression analysis was used to assess potential predictors of malignancy among ECG abnormalities. All-cause mortality at follow-up was evaluated. ResultsOf 322 patients, 98 (30.4%) had malignant tumors. Compared with patients with benign masses, those with malignant tumors exhibited a higher heart rate, right-axis deviation, greater depolarization, repolarization abnormalities, and bradyarrhythmia at presentation. Regarding specific ECG features, a higher heart rate on admission (P = .014), bradyarrhythmias (P = .009), ischemic-like repolarization abnormalities (ST-segment deviation, both depression and elevation, and negative T-wave; P <.001), low voltages (P = .001), and right-axis deviation (P = .025) were identified as independent predictors of malignancy. Considering these specific ECG alterations, a malignancy-oriented ECG was associated with higher mortality at follow-up (median 20.7 months). ConclusionECG frequently is abnormal in cases of malignant cardiac tumors. Some specific ECG changes are strongly suggestive for malignancy and type of infiltration.

Early Screening for Long QT Syndrome and Cardiac Anomalies in Infants: A Comprehensive Study.

(1) Background: Sudden Infant Death Syndrome (SIDS) represents sudden and unexplained deaths during the sleep of infants under one year of age, despite thorough investigation. Screening for a prolonged QTc interval, a marker for Long QT Syndrome (LQTS), should be conducted on all newborns to reduce the incidence of SIDS. Neonatal electrocardiograms (ECGs) could identify congenital heart defects (CHDs) early, especially those not detected at birth. Infants with prolonged QTc intervals typically undergo genetic analysis for Long QT Syndrome. (2) Methods: The study involved infants aged 20-40 days, born with no apparent clinical signs of heart disease, with initial ECG screening. Infants with prenatal diagnoses or signs/symptoms of CHDs identified immediately after birth, as well as infants who had previously had an ECG or echocardiogram for other medical reasons, were excluded from the study. We used statistical software (SPSS version 22.0) to analyze the data. (3) Results: Of the 42,200 infants involved, 2245 were enrolled, with 39.9% being males. Following this initial screening, 164 children (37.8% males) with prolonged QTc intervals underwent further evaluation. Out of these 164 children, 27 children were confirmed to have LQTS. However, only 18 children were finally investigated for genetic mutations, and mutations were identified in 11 tests. The most common mutations were LQT1 (54.5%), LQT2 (36.4%), and LQT3 (1 patient). Treatment options included propranolol (39.8%), nadolol (22.2%), inderal (11.1%), metoprolol (11.1%), and no treatment (16.7%). The most common abnormalities were focal right bundle branch block (54.5%), left axis deviation (9.2%), and nonspecific ventricular repolarization abnormalities (7.1%). Multiple anomalies were found in 0.47% of children with focal right bundle branch block. Structural abnormalities were associated with specific features in 267 patients (11.9%), primarily isolated patent foramen ovale (PFO) at 61.4%. (4) Conclusions: This screening approach has demonstrated effectiveness in the early identification of LQTS and other cardiac rhythm anomalies, with additional identification of mutations and/or prolonged QTc intervals in family members. Identifying other ECG abnormalities and congenital heart malformations further enhances the benefits of the screening.

Energy wavelet signal processed ECG and standard 12 lead ECG: Diagnosis of early diastolic dysfunction

BackgroundLeft ventricular (LV) diastolic dysfunction (LVDD) is the result of impaired LV relaxation and identifies those at risk of developing heart failure. Echocardiography has been used as the gold standard to identify early LVDD. The signal processed electrocardiogram (hsECG) has demonstrated effectiveness to detect early LVDD. Whether or not the standard 12‑lead electrocardiogram (ECG) can accurately predict early LVDD is not known. MethodsA standard 12‑lead ECG including signal processing (hsECG) was performed in 569 patients. Patients with atrial fibrillation, bundle branch block, pre-excitation, left ventricular hypertrophy or known cardiovascular disease were excluded, leaving 464 examinations for analysis. Early LVDD was diagnosed by established methods using echocardiography. Repolarization abnormalities (T wave discordance) in V1, V6, I and aVL and the hsECG were compared to the echocardiographic findings to establish diagnostic accuracy. ResultsA total of 84 (18.1%) patients were diagnosed with early LVDD. A combination of a borderline or abnormal finding on the hsECG produced the best diagnostic model (sensitivity 84.5%, specificity 47.9%). The best performing ECG lead was V1 with a sensitivity of 38.1% and specificity of 92.1%. Regression analysis demonstrated increasing age and V1 to be predictive of LVDD. ConclusionsThe hsECG displayed reasonable ability to detect early LVDD. Other than V1, repolarization abnormalities on the standard 12‑lead ECG did not. While lead V1 showed promise in detecting LVDD, whether this or any other simple ECG variable can predict future LVDD would be of further interest.

Associations between Total Atherosclerosis Burden of Baroreceptor-Resident Arteries and ECG Abnormalities after Acute Ischemic Stroke.

Electrocardiogram (ECG) abnormalities are the most common cardiac complications after acute ischemic stroke (AIS) and predict poor outcomes. The arterial baroreflex is an essential determinant of cardiovascular autonomic regulation, with receptors mainly residing in carotid sinuses and aortic arch. The atherosclerosis of these baroreceptor-resident arteries (BRA) is very common in AIS patients and might impair baroreflex function. However, the associations between the atherosclerosis of BRA and ECG abnormalities after AIS are still unknown. In total, 228 AIS patients within 7 days after onset without a pre-existing heart disease were prospectively recruited. With computed tomography angiography, atherosclerosis conditions in 10 segments of the carotid sinuses and aortic arch were scored and summed as the Total Atherosclerosis Burden of BRA (TAB-BRA), and asymptomatic coronary artery stenosis (ACAS) ≥50% was simultaneously assessed. We performed 12-lead ECG to dynamically detect abnormal repolarization, and 24 h Holter ECG to monitor arrhythmias and heart rate variability (HRV) parameters, which are reliable indicators to assess cardiac autonomic function. We found that TAB-BRA was positively associated with abnormal repolarization (OR 1.09; CI% 1.03-1.16; p = 0.003) and serious cardiac arrhythmias (OR 1.08; CI% 1.01-1.15; p = 0.021). In addition, TAB-BRA was an important predictor of abnormal repolarization, persisting over 3 days (OR 1.17; CI% 1.05-1.30; p = 0.003). However, ACAS ≥ 50% did not relate to these ECG abnormalities. TAB-BRA was negatively correlated with parasympathetic-related HRV parameters. Our results indicated that AIS patients with a high TAB-BRA are more likely to have ECG abnormalities and delayed normalization, which may relate to the decreased cardiac parasympathetic activity, but not the accompanied ACAS ≥ 50%.

A PARTICULAR CASE OF CARDIAC ARREST

Abstract 88–year–old man with arterial hypertension, cognitive impairment, carrier of dual–chamber PM due to sinus node disease. Diagnosis of congenital long QT syndrome (LQT1) approximately 20 years ago during family screening (syncopal episodes in his son positive for LQT1), no history of syncope or major arrhythmias. In home therapy with mirtazapine and norvasc. He arrived in our cardiac intensive care unit for ACC on torsade de pointes trated with two cycles of CPR and 1 DC shock at 200 Joules with ROSC. On arrival ECG evidence of electrically induced ventricular rhythm, QTc 850 msec. On echocardiogram akinesia of the mid–basal segments of all the LV walls (takotsubo–like) with EF 25–30%. On coronary angiography non critical multivessel coronary disease. At laboratory tests increase of WBC, PCR and PCT, slight plateau movement of troponin, normal electrolytes. The patient underwent a chest CT scan with evidence of an inflammatory focus for which antibiotic therapy was started. Congenital long QT syndrome (LQTS) is an inherited condition characterized by prolongation of the QT interval (more than 450 ms in men and 460 ms in women), associated with repolarization abnormalities. There are three main forms transmitted via AD: LQT1, LQT2 and LQT3. The most common variant is LQT1 caused by a loss of function mutation in the KCNQ1 gene which causes a reduction in the outgoing potassium current during phase 3 of the action potential. In these patients, episodes of syncope caused by torsade de pointes, major arrhythmias and sudden cardiac death are frequent. Patients with LQTS should avoid taking drugs that can prolong the QT interval such as some antipsychotics, antidepressants (like mirtazapina that can cause QT prolongation, torsade de pointes, ventricular tachycardia and sudden cardiac death if administered at high doses or in patients with predisposing factors), antibiotics. Furthermore, there are various factors that can influence the QT prolongation: electrolyte alterations, physical stress, cerebrovascular events. The use of mirtazapine for a long period in association with takotsubo syndrome (probably triggered by underlying pneumonia) in a patient with LQTS, may have resulted in massive lengthening of the QT interval causing torsade de pointes and therefore ACC. During the hospitalization, mirtazapine was suspended and nadolol was introduced with a progressive reduction of the QT segment. No new arrhythmic events were recorded.