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.

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.

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.

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.

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.

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.

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.

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 Effective Novel Index for Predicting the Recurrence of Atrial Fibrillation Ablation: P Wave Duration-to-Amplitude Ratio.

OBJECTIVE: Atrial fibrillation is the most common arrhythmia observed in the clinical practice. Pulmonary vein isolation is a well established treatment option for atrial fibrillation but is limited by recurrence. Previous studies have demonstrated that abnormal P wave indices were associated with adverse atrial remodeling and its role in predicting atrial fibrillation recurrence. In the present study, we aimed to evaluate the place of a novel index as we named P wave duration-to-amplitude ratio in predicting the recurrence of atrial fibrillation. METHODS: Patients who underwent pulmonary vein isolation for symptomatic drug-resistant atrial fibrillation between January 2016 and March 2018 were retrospectively screened. A total of 111 patients were enrolled in the current study. P wave indices of the patients were calculated by precisely measuring the electrocardiogram traces recorded with an electrophysiology recording system. RESULTS: While P wave duration (129 ± 18.4 vs. 109 ± 15.7 ms, P <.001), P wave duration-toamplitude ratio (1072.7 ± 528.3 vs. 626.9 ± 368 ms/mV, P <.001), P wave peak time (65 ± 12 vs. 54 ± 10 ms, P <.001), and P wave dispersion (49 ± 14.1 vs. 27.9 ± 17 ms, P =.001) values were significantly higher in the atrial fibrillation recurrence (+) group, the P wave amplitude (0.12 ± 0.05 vs. 0.18 ± 0.02 mV, P <.001) value was found to be lower. A P wave duration-t o-amplitude ratiovalue of >830 ms/mV has 61.8% sensitivity and 88.4% specificity for the prediction of the atrial fibrillation recurrence (area of under the curve [AUC], 0.727). CONCLUSION: P wave duration-to-amplitude ratio, which may be considered as an indicator of the temporal and electrical propagation of the P wave in the atria, can predict atrial fibrillation ablation recurrence.

Invasive Heart Rate Control as a Salvage Therapy in Amiodarone-induced Thyroid Storm.

Atrial fibrillation (AF) is the most common arrhythmia, and amiodarone is one of the most commonly used drugs for medical cardioversion of AF, which should be used carefully due to its toxic effects. Amiodarone-induced thyrotoxicosis (AIT) may develop in amiodarone-treated patients. In contrast, the most common rhythm disturbance accompanying a thyroid storm is AF. This association may put both AF and thyrotoxicosis treatment into a vicious circle, leading to AI cardiomyopathy. Herein, we aimed to present atrioventricular node ablation as a salvage therapy in a patient with AIT who had AF-causing hemodynamic impairment, resistance to medical therapy, and cardioversion.

Catheter Ablation for Atrial Fibrillation in Patients ≤30 Years of Age.

Pulmonary vein (PV) automaticity is an established trigger for paroxysmal atrial fibrillation (PAF), making PV isolation (PVI) the cornerstone of catheter ablation. However, data on triggers for atrial fibrillation (AF) and catheter ablation strategy in very young patients aged <30 years are sparse. A total of 51 young patients (mean age 24.0 ± 4.2 years, 78.4% men) with drug-refractory PAF underwent electrophysiology (EP) study and ablation at 5 EP centers. None of the patients had structural heart disease or family history of AF. EP study induced supraventricular tachycardia (SVT) in 12 patients (n = 12, 23.5%): concealed accessory pathway mediated orthodromic atrioventricular reentrant tachycardia in 3 patients, typical atrioventricular nodal reentrant tachycardia in 6 patients, left superior PV tachycardia in 1 patient, left atrial appendage tachycardia in 1 patient, and typical atrial flutter in 1 patient. In patients with induced SVTs, SVT ablation without PVI was performed as an index procedure, except for the patient with atrial flutter who received cavotricuspid isthmus ablation in addition to PVI. Remaining patients underwent radiofrequency (n = 15, 29.4%) or second-generation cryoballoon-based PVI (n = 24, 47%). There were no major complications related to ablation procedures. Follow-up was based on outpatient visits including 24-hour Holter-electrocardiogram at 3, 6, and 12 months after ablation, or additional Holter-electrocardiogram was ordered in case of symptoms suggesting recurrence. Recurrence was defined as any atrial tachyarrhythmia (ATA) episode >30 seconds after a 3-month blanking period. A total of 2 patients with atrioventricular nodal reentrant tachycardia, 1 with left atrial appendage tachycardia, experienced AF recurrence within the first 3 months and received PVI. After the 3-month blanking period, during a median follow-up of 17.0 ± 10.1 months, 44 of 51 patients (86.2%) were free of ATA recurrence. In the PVI group, 33 of 39 patients (84.6%) experienced no ATA recurrence. In conclusion, SVT substrate is identified in around a quarter of young adult patients with history of AF, and targeted ablation without PVI may be sufficient in the majority of these patients. PVI is needed in the majority and is safe and effective in this population.

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.

Current clinical practice of cardiac resynchronization therapy in Turkey: Reflections from Cardiac Resynchronization Therapy Survey-II.

OBJECTIVE: Cardiac resynchronization therapy (CRT) has been shown to reduce mortality in selected patients with heart failure with reduced ejection fraction (HFrEF). CRT Survey-II was a snapshot survey to assess current clinical practice with regard to CRT. Herein, we aimed to compare Turkish data with other countries of European Society of Cardiology (ESC). METHODS: The survey was conducted between October 2015 and December 2016 in 42 ESC member countries. All consecutive patients who underwent a de novo CRT implantation or a CRT upgrade were eligible. RESULTS: A total of 288 centers included 11,088 patients. From Turkey, 16 centers recruited 424 patients representing 12.9% of all implantations. Compared to the entire cohort, Turkish patients were younger with a lower proportion of men and a higher proportion with ischemic etiology. Electrocardiography (ECG) showed sinus rhythm in 81.5%, a QRS duration of <130 ms in 10.1%, and ≥150 ms in 63.8% of patients. Left bundle branch block (LBBB) was more common. Median left ventricular ejection fraction (LVEF) was 25%, lower than in the overall ESC cohort, but NYHA class was more often II. Most common indication for CRT implantation was HF with a wide QRS (70.8%). Almost 98.3% of devices implanted were CRT-D, in contrast to the overall cohort. Fluoroscopy time was longer, but duration of overall procedure was shorter. LV lead implantation was unsuccessful in 2.6% patients. Periprocedural complication rate was 6.3%. The most common complication was bleeding. Remote monitoring was less utilized. CONCLUSION: These are the first observational data reflecting the current CRT practice in Turkey and comparing it with other countries of Europe. Findings of this study may help detect gaps and provide insights for improvement.

[Ablation of ventricular tachycardia in a patient with a left ventricular assist device]. / Sol ventrikül destek cihazi olan bir hastada ventriküler tasikardi ablasyonu.

The use of a left ventricular assist device (LVAD) as a bridge to heart transplantation (HTx) or as a destination therapy in patients with a contraindication for HTx is increasing. However, nearly half of the patients with LVAD support experience a ventricular arrhythmia (VA) in the first year. The history of a pre-LVAD VA is one of the most powerful predictors of VA after LVAD implantation. The clinical experience and data about ablation of a VA in patients with an LVAD are limited. There are important issues to be considered before and during the procedure in LVAD patients compared to other VA ablation patients. This is a report of ablation of intractable ventricular tachycardia in a patient with a LVAD.

Premature ventricular complexes: diagnostic and therapeutic considerations in clinical practice : A state-of-the-art review by the American College of Cardiology Electrophysiology Council.

Premature ventricular complexes (PVCs) are common arrhythmias in the clinical setting. PVCs in the structurally normal heart are usually benign, but in the presence of structural heart disease (SHD), they may indicate increased risk of sudden death. High PVC burden may induce cardiomyopathy and left ventricular (LV) dysfunction or worsen underlying cardiomyopathy. Sometimes PVCs may be a marker of underlying pathophysiologic process such as myocarditis. Identification of PVC burden is important, since cardiomyopathy and LV dysfunction can reverse after catheter ablation or pharmacological suppression. This state-of-the-art review discusses pathophysiology, clinical manifestations, how to differentiate benign and malignant PVCs, PVCs in the structurally normal heart, underlying SHD, diagnostic procedures (physical examination, electrocardiogram, ambulatory monitoring, exercise testing, echocardiography, cardiac magnetic resonance imaging, coronary angiography, electrophysiology study), and treatment (lifestyle modification, electrolyte imbalance, medical, and catheter ablation).