Challenging wide QRS tachycardia diagnosis: One trigger two mechanisms.

The coexistence of different types of wide QRS complex tachycardias induced by the same trigger has rarely been observed. The electrical instability and incessant nature of tachycardias can cause tachycardiomyopathy and will not allow accurate diagnosis during an electrophysiological study (EPS). In case of an electrical storm, elimination of the trigger may be the first approach to provide patient stability. We report a successfully managed case of repetitive initiation of pleomorphic ventricular tachycardia and Mahaim-type antidromic atrioventricular reentrant tachycardia, induced by a premature ventricular complex in the right ventricular outflow tract.

Combining conventional technique with fluoroscopy integration module in accessory pathway ablation.

INTRODUCTION: Accessory pathway (AP) ablation is a straightforward approach with high success rates, but the fluoroscopy time (FT) is significantly longer in conventional technique. Electroanatomical mapping systems (EMS), reduce the FT, but anatomical and activation mapping may prolong the procedure time (PT). The fluoroscopy integration module (FIM) uses prerecorded fluoroscopy images and allows ablation similar to conventional technique without creating an anatomical map. In this study, we investigated the effects of combining the FIM with traditional technique on PT, success, and radiation exposure. METHODS: A total of 131 patients who had undergone AP ablation were included in our study. In 37 patients, right and left anterior oblique (RAO-LAO) images were acquired after catheter placement and integrated with the FIM. The ablation procedure was then similar to the conventional technique, but without the use of fluoroscopy. For the purpose of acceleration, anatomical and activation maps have not been created. Contact-force catheters were not used. 94 patients underwent conventional ablation using fluoroscopy only. RESULTS: FIM into AP ablation procedures led to a significant reduction in radiation exposure, lowering FT from 7.4 to 2.8 min (p < .001) and dose-area product from 12.47 to 5.8 µGym² (p < .001). While the FIM group experienced a reasonable longer PT (69 vs. 50 min p < .001). FIM reduces FT regardless of operator experience and location of APs CONCLUSION: Combining FIM integration with conventional AP ablation offers reduced radiation exposure without compromising success rates and complication.

Lead related atrial perforation mimicking inferior ST elevation myocardial infarction.

ST-elevation myocardial infarction (STEMI) is a life-threatening clinical condition that requires immediate intervention, mostly caused by complete occlusion of epicardial vessels. Other diseases such as myocarditis, pericarditis, electrolyte disturbance, and early repolarization may mimic. We present a rare case of atrial lead-related atrial perforation which mimics inferior STEMI.

Pre-procedural imaging and atrial tachycardia ablation in a patient with complex congenital heart disease.

Atrial tachycardias (AT) are common cardiac arrhythmia disorder for congenital heart disease (CHD). The anatomic substrate that surgical suture lines, scar tissue, or prosthetic material may cause pre-existing atrial conduction abnormalities which leads to the underlying mechanism of reentrant ATs. Radiofrequency Catheter ablation (RFCA) is used in the treatment of atrial tachycardia in CHD patients. However venous system abnormalities may complicate the procedure. We report that ablation of a case with atrial tachycardia with challenging anatomy (persistent left superior vena cava draining into the left atrium, coronary sinus agenesis, inferior vena cava (IVC) agenesis, azygos system drained to the superior vena cava, and repaired ventricular septal defect). This case report discusses the key points of access to cardiac chambers and mapping in very rare challenging anatomy.

Improving implant training for physicians and their teams in under-represented regions.

The burden of cardiovascular disease is increasing globally, with low- and middle-income countries (LMICs) absorbing most of the burden while lacking the necessary healthcare infrastructure to combat the increase. In particular, the disparity in pacemaker implants between high-income countries and LMICs is glaring, partially spurned by reduced numbers of physicians and supporting staff who are trained in pacemaker implant technique. Herein, we will discuss current pacemaker implant training models, outline training frameworks that can be applied to underserved regions, and review adjunctive training techniques that can help supplement traditional training models in LMICs.

The predictive value of electrocardiographic polarization parameters on appropriate ICD shock in primary prevention heart failure patients.

OBJECT: The effect of frontal QRS-T angle, Tp-e and Tp-e/QT ratio on cardiac events have been shown in many studies. In this study, we aimed to determine the prognostic value of frontal QRS-T angle, TPe and Tp-e/QT ratio on ICD shock in patients who had ICD (Implantable Cardioverter Defibrillator) implanted due to heart failure with reduced ejection fraction (HFrEF). MATERIAL AND METHOD: 158 patients with HFrEF who had previous ICD implantation were retrospectively analyzed. 27 patients were found to have an appropriate shock. Frontal QRS-T angle, Tp-e interval, Tp-e/QT ratio were calculated by evaluating the basal ECG records of the patients. Comparisons of these arrhythmogenic predictors were made in patients with and without ICD shock at follow-up. RESULT: When 158 patients with previous ICD implantation were analyzed in two groups with and without ICD shock, the number of patients with frontal QRS-T angle >120°, Tp-e interval > 105 ms, Tp-e/QT > 0.2 in the shock group (n: 27) was found to be high with a different significance (p:<0.01, p:<0.01, p:<0.01). There was no significant difference between the two groups regarding other ECG parameters such as QRS duration, QT interval, PR interval, fragmented QRS and positive T wave. In addition, more amiodarone use was observed in the shock group, and more hyperlipidemia cases were observed in the non-shocked group (p:0.01; p:<0.01). CONCLUSION: Increased frontal QRS-T angle, Tp-e interval, and Tp-e/QT ratio are arrhythmogenic parameters and predict appropriate ICD shock.

Evaluation of left atrial and left ventricular functions in patients with Wolff-Parkinson-White syndrome before and after radiofrequency catheter ablation using three-dimensional speckle tracking echocardiography.

BACKGROUND: Wolff-Parkinson-White (WPW) syndrome is one of the most common congenital cardiac abnormalities among ventricular pre-excitation syndromes. Radiofrequency catheter ablation (RFCA) treatment of accessory pathways (APs) in WPW patients is an established curative therapy restoring normal atrioventricular conduction. We have not encountered any studies evaluating both the LA and LV functions of these patients before and after RFCA with three dimensional-speckle tracking echocardiography (3D-speckle tracking echocardiography (STE)). AIM: The purpose of the current study was to assess the LA and LV functions in patients with WPW syndrome before and after RFCA using 3D-STE. METHODS: A total of 21 patients with WPW syndrome who had been scheduled for RFCA were prospectively recruited for this study. 3D-STE examinations of the patients were performed 12-24 h before ablation and 1 month after ablation. RESULTS: The LV-global longitudinal strain (LV-GLS) and LV-global circumferential strain (LV-GCS) were significantly depressed in the pre-RFCA WPW group than in the control group (-14.3 ± 2.1 vs. -21.5 ± 2.2, p < .001; -12.6 ± 1.8 vs. -20.4 ± 1.8, p < .001, respectively). The left atrial strain-reservoir (LAS-r) and LAS-active were significantly decreased in the pre-RFCA WPW group than in the control group (31.9 ± 2.4 vs. 48.8 ± 2.6, p < .001; 11.7 ± 2 vs. 26.5 ± 2.1, p < .001, respectively). The LV-GLS, LV-GCS, LAS-r, and LAS-active values improved after RFCA compared to before. CONCLUSION: The results of our study indicated that there are subclinical impairments in LV and LA myocardial dynamics in the apparently healthy WPW patients, and these deteriorations improve after RFCA of AP.

An unusual 'bow tie' image in pacemaker implantation.

Upper venous system anatomic variations may cause difficulties during cardiac pacemaker implantation. Persistent left superior vena cava (PLSVC) and absent right superior vena cava could be an arrhythmogenic source of atrial arrhythmias and cardiac conduction disease. We represent dual-chamber pacemaker implantation in a patient with a very rare upper venous system anomaly, paroxysmal atrial fibrillation, sick sinus syndrome, that cause unusual fluoroscopic image.

Comparison of electrophysiological characteristics of right- and left-sided Mahaim-type accessory pathways.

AIMS: Mahaim-type accessory pathways (MAPs) are generally right-sided due to the embryological differentiation, but left-sided localization is also possible. This study aims to compare the clinical and electrophysiological characteristics of right- and left-sided MAPs. METHODS: Of 251 patients diagnosed with AP by electrophysiological study between November 2015 and February 2020, 12 patients with MAP were included (right sided n = 8, left sided n = 4). MAP was diagnosed if; (1) no retrograde conduction; (2) anterograde decremental conduction; (3) adenosine sensitivity; and (4) Mahaim potential at successful ablation site were present. RESULTS: Ten of twelve MAPs were clustered on the lateral walls of the mitral (n = 3, 75%) and tricuspid annuli (n = 7, 87.5%). Right-sided MAPs were mostly long pathways extending toward the conduction system whereas left-sided MAPs were short extending toward the neighboring myocardium. For right- and left-sided APs, the median QRS times were 129 and 156 ms (p = .042), the median VAbl -RVApex intervals were -12 and 64 ms (p = .007), the median QRS-V(His) intervals were 16 and 86 ms (p = .120), and the median VAbl -QRS interval was -8 and 12 ms (p = .017), respectively. Coexistence of dual atrioventricular node physiology was observed only in right-sided APs (n = 3, 37.5%). CONCLUSION: MAPs are more typically located on the right but may rarely be seen on the left. Catheter ablation was associated with high success without complications.

Repeat procedure is a new independent predictor of complications of atrial fibrillation ablation.

AIMS: Atrial fibrillation (AF) ablation has made huge progress with respect to innovation, efficacy, and safety, however, complications are still present. Recent studies examined various predictors of complications. However, limited data exist regarding the role of a repeat procedure. Our aim was the prospective evaluation of the incidence and predictors of complications related to AF ablation procedures in consecutive patients, including repeat procedures. METHODS AND RESULTS: All ablation procedures for AF between January 2013 and December 2015 were analysed in our electrophysiology laboratory. During the study period 1243 procedures were analysed [394 female, median age 62 (55-69)]. Overall complication rate was 6.84%, major complication rate was 2.82%. Major complications were the following: 18 pericardial tamponades; 5 pseudoaneurysms; 1 arteriovenous fistula; 6 thromboembolic cerebrovascular events; 3 pulmonary vein stenosis; and 2 atrioventricular blocks. No atrio-oesophageal fistula or procedure related death occurred. Univariate analysis for overall complications showed that age ≥ 65 years (P = 0.0231), female gender (P = 0.0438), hypertension (P = 0.0488), CHA2DS2-VASc score ≥ 2 (P = 0.0156), and previous AF ablation procedure (P < 0.0001) is associated with higher risk for adverse events. Multivariate analysis showed that the only independent predictor of overall complications was previous AF ablation procedure (P < 0.0001). Similarly, the only predictor of major complications was previous AF ablation procedure (P < 0.0001). CONCLUSION: Incidence of complications associated with AF ablation in our high volume electrophysiology laboratory is similar to other cohorts. The only independent predictor of complications was previous AF ablation procedure in our series.

Long-term single-centre large volume experience with transseptal endocardial left ventricular lead implantation.

AIMS: The aim of our study was to investigate the long-term efficacy and safety of transseptal endocardial left ventricular lead implantation (TELVLI). METHODS AND RESULTS: Transseptal endocardial left ventricular lead implantation was performed in 54 patients (44 men, median age 69, New York Heart Association III-IV stage) between 2007 and 2017 in a single centre. In 36 cases, the transseptal puncture (TP) was performed via the femoral vein, and in 18 cases, the TP and also the left ventricular (LV) lead placement were performed via the subclavian vein. An electrophysiological deflectable catheter was used to reach the LV wall through the dilated TP hole. The LV lead implantation was successful in all patients. A total of 54 patients were followed up for a median of 29 months [interquartile range (IQR) 8-40 months], the maximum follow-up time was 94 months. Significant improvement in the LV ejection fraction was observed at the 3-month visit, from the median of 27% (IQR 25-34%) to 33% (IQR 32-44%), P < 0.05. Early lead dislocation was observed in three cases (5%), reposition was performed using the original puncture site in all. The patients were maintained on anticoagulation therapy with a target international normalized ratio between 2.5 and 3.5. Four thromboembolic events were noticed during follow-up. A total of 27 patients died, with a median survival of 15 months (IQR 6-40). CONCLUSION: The TELVLI is an effective approach for cardiac resynchronization therapy (CRT) however it is associated with a substantial thromboembolic risk (7%).

The role of baseline and post-procedural frontal plane QRS-T angles for cardiac risk assessment in patients with acute STEMI.

BACKGROUND: To our knowledge, no study so far investigated the importance of post-procedural frontal QRS-T angle f(QRS-T) in ST segment elevation myocardial infarction (STEMI). The aim of our study was to investigate the role of baseline and post-procedural f(QRS-T) angles for determining high risk STEMI patients, and the success of reperfusion. METHODS: A total of 248 patients with first acute STEMI that underwent primary percutaneous coronary intervention (pPCI) or thrombolytic therapy (TT) between 2013 and 2014 were included in this study. Baseline f(QRS-T) angle was defined as the angle which measured from the first ECG at the time of hospital admission. Post-procedural (QRS-T) angle was defined according to the treatment strategy as follows: the angle which measured from the post-PCI ECG in patients treated with pPCI; the angle which measured from the ECG taken 90 min after onset of therapy in patients treated with TT. RESULTS: The baseline (101.9° ± 48.0 vs. 72.1° ± 49.1, p = 0.014) and post-procedural f(QRS-T) angles (95.7° ± 48.1 vs. 58.1° ± 47.1, p = 0.002) were significantly higher in patients who developed in-hospital mortality than the patients who did not develop in-hospital mortality. Also, f(QRS-T) angle measured at 90 min was significantly lower in patients with successful thrombolysis group compared to failed thrombolysis group (53.2° ± 42.8 vs. 77.3° ± 52.9, p = 0.033), whereas baseline f(QRS-T) angle was similar between two groups (78.6° ± 53.4 vs. 78.9° ± 54.0, p = 0.976). Multivariate analysis showed that post-procedural f(QRS-T) angle ≥89.6° (odds ratio: 3.541, 95% confidence interval: 1.235-10.154, p = 0.019), but not baseline f(QRS-T) angle, was independent predictor of in-hospital mortality. CONCLUSION: f(QRS-T) angle may be used as a beneficial tool for determining high risk patients in acute STEMI. Unlike previous studies, we showed for the first time that that post-procedural f(QRS-T) can predict in-hospital mortality and TT failure.

Longer right to left ventricular activation delay at cardiac resynchronization therapy implantation is associated with improved clinical outcome in left bundle branch block patients.

AIMS: Data on longer right to left ventricular activation delay (RV-LV AD) predicting clinical outcome after cardiac resynchronization therapy (CRT) by left bundle branch block (LBBB) are limited. We aimed to evaluate the impact of RV-LV AD on N-terminal pro-B-type natriuretic peptide (NT-proBNP), ejection fraction (EF), and clinical outcome in patients implanted with CRT, stratified by LBBB at baseline. METHODS AND RESULTS: Heart failure (HF) patients undergoing CRT implantation with EF ≤ 35% and QRS ≥ 120 ms were evaluated based on their RV-LV AD at implantation. Baseline and 6-month clinical parameters, EF, and NT-proBNP values were assessed. The primary endpoint was HF or death, the secondary endpoint was all-cause mortality. A total of 125 patients with CRT were studied, 62% had LBBB. During the median follow-up of 2.2 years, 44 (35%) patients had HF/death, 36 (29%) patients died. Patients with RV-LV AD ≥ 86 ms (lower quartile) had significantly lower risk of HF/death [hazard ratio (HR): 0.44; 95% confidence interval (95% CI): 0.23-0.82; P = 0.001] and all-cause mortality (HR: 0.48; 95% CI: 0.23-1.00; P = 0.05), compared with those with RV-LV AD < 86 ms. Patients with RV-LV AD ≥ 86 ms and LBBB showed the greatest improvement in EF (28-36%; P<0.001), NT-proBNP (2771-1216 ng/mL; P < 0.001), and they had better HF-free survival (HR: 0.23, 95% CI: 0.11-0.49, P < 0.001) and overall survival (HR: 0.35, 95% CI: 0.16-0.75; P = 0.007). There was no difference in outcome by RV-LV AD in non-LBBB patients. CONCLUSION: Left bundle branch block patients with longer RV-LV activation delay at CRT implantation had greater improvement in NT-proBNP, EF, and significantly better clinical outcome.

Comparison of the Effects of Epicardial and Endocardial Cardiac Resynchronization Therapy on Transmural Dispersion of Repolarization.

BACKGROUND: Despite significant improvements in cardiac output and functional capacity with cardiac resynchronization therapy (CRT), incidence of sudden cardiac death still remains high. Reversal of physiological myocardial activation sequence during epicardial pacing increases the transmural dispersion of repolarization (TDR). The aim of this study was to compare the effects of endocardial and epicardial biventricular pacing on repolarization parameters in the same patient group. METHODS: Seven patients who had transseptal endocardial left ventricle (LV) lead placement, in whom epicardial CRT had failed due to coronary sinus (CS) lead dislodgement after successful implantation, were admitted to the study. LV endocardial leads were implanted through the interatrial septum in a lateral position. Electrocardiograms (ECGs) were scanned before and after successful epicardial and endocardial biventricular pacing and analyzed using digital calipers. ECG markers of TDR (TpTe and TpTe/QT ratio) were measured and compared. RESULTS: Baseline QRS durations (161.7 ± 15.9 ms vs 162.2 ± 17.8 ms, P = 0.95), TpTe values (107.1 ± 20.5 ms vs 108.5 ± 17.6 ms, P = 0.89), and TpTe/QT ratios (0.24 ± 0.05 vs 0.24 ± 0.03, P = 0.88) were similar before epicardial and endocardial CRT. QRS interval reduction was similar (-28.3 ± 11.6 ms vs -29.1 ± 11.4 ms, P = 0.89) in both groups. Compared to transseptal endocardial CRT, epicardial CRT was associated with a significant increase in TpTe (17.1 ± 19.5 ms vs -12.6 ± 18.9 ms, P = 0.01) and TpTe/QT ratio (0.03 ± 0.04 vs -0.02 ± 0.03, P = 0.04). CONCLUSION: Transseptal LV endocardial pacing is associated with significant reduction in TDR characteristics compared to epicardial pacing in CRT. Further studies are warranted to determine whether these effects may contribute to reduction of arrhythmias in patients with CRT.

Clinical Heterogeneity in Patients with Long QT Syndrome and Segregation of Single Nucleotide Variants and Clinical Symptoms in 17 Affected Families.

Introduction: Long QT syndrome (LQTS) is a disorder of ventricular myocardial repolarization characterized by a prolonged QT interval on the electrocardiogram. It increases the risk of ventricular arrhythmias, which can cause syncope or sudden cardiac death. In this study, we study the genotype-phenotype relationships of patients referred to us with suspected arrhythmia syndrome. Methods: Seventeen cases and their twenty relatives were evaluated. Next-generation sequencing analysis was performed for 17 LQTS-related genes. Results: We detected seventeen single nucleotide variants (SNVs) with potential pathogenic significance in 26 of the 36 subjects analyzed. KCNH2 c.172G>A, KCNQ1 c.1768G>A, ANK2 c.4666A>T, c.1484_1485delCT, KCNH2 c.1888G>A were reported as pathogenic or likely pathogenic in HGMD variant classification database. Conclusion: Current study pointed out that early diagnosis can be life-saving for patients and their families by taking family history and detailed examination. Also, we highlight the clinical heterogeneity of arrhythmia syndrome through a patient with a dual phenotype.

Single coronary artery originating from the right sinus of Valsalva and hypoplastic left anterior descending artery: An extremely rare combination of congenital coronary artery anomalies.

A 57-year-old woman with a history of hypertension, hyperlipidemia and stable angina is described. A coronary angiogram revealed the presence of a single coronary artery arising from the right sinus of Valsalva that was providing the left anterior descending (LAD), left circumflex and right coronary artery branches, with noncritical occlusive atherosclerotic plaques at the proximal circumflex artery. A small hypoplastic LAD tapering proximally was found, but no LAD and compensatory collateral circulatory vessels were observed distally. In the present report, the authors discuss this extremely rare combination of congenital coronary anomalies and their clinical implications.