Conventional Fluoroscopy-Guided vs Zero-Fluoroscopy Catheter Ablation of Supraventricular Tachycardias

Purpose: The aim of this study was to evaluate the safety and efficacy of zero-fluoroscopy (ZF) catheter ablation (CA) for supraventricular tachycardias (SVT).Methods: 584 consecutive patients referred to our institution for CA of SVT were analysed. Patients were categorised into two groups; zero-fluoroscopy (ZF) group and conventional fluoroscopy (CF) group. The ZF group was further divided into two subgroups (adults and paediatric). Patient characteristics, procedural information, and follow-up data were compared. Results: The ZF group had a higher proportion of paediatric patients (42.2% vs 0.0 %; p < 0.001), resulting in a younger age (30.9 ± 20.3 years vs 52.7 ± 16.5 years; p < 0.001) and lower BMI (22.8 ± 5.7 kg/m2 vs 27.0 ± 5.4 kg/m2; p < 0.001). Procedure time was shorter in the ZF group (94.2 ± 50.4 min vs 104.0 ± 54.0 min; p = 0.002). There were no major complications and the rate of minor complications did not differ between groups (0.0% vs 0.4%; p = 0.304). Acute procedural success as well as the long-term success rate when only the index procedure was considered did not differ between groups (92.5% vs 95.4%; p = 0.155; 87.1% vs 89.2%; p = 0.422). When repeated procedures were included, the long-term success rate was higher in the ZF group (98.3% vs 93.5%; p = 0.004). The difference can be partially explained by the operators' preferences.Conclusion: The safety and efficacy of ZF procedures in adult and paediatric populations are comparable to that of CF procedures.

Radiofrequency Catheter Ablation for Supraventricular Tachycardias: A Six-Year Single Centre Experience at NICVD

Pharmacological therapy is mostly employed in the management of supraventricular tachyarrhythmias in different part of the world including Bangladesh. However, Radiofrequency catheter ablation has been found to be highly effective and safe in the treatment of such tachyarrhythmias. Objective: The current study is aimed at sharing our experiences of 842 patients who presented with Supraventricular tachycardias and were diagnosed by EPS and treated with Radiofrequency catheter ablation. Methods: This descriptive study has been carried out in the cardiac electro physiology Department of NICVD, Dhaka, Bangladesh from 2nd January 2015 to 31st December, 2020. Electrophysiology study(EPS) was carried out to identity and diagnose the mechanism of different SVTs in 842 consecutive patients. RF catheter ablation was used to interrupt the tachycardia circuit. Results: Out of a total 842 patients who underwent Electrophysiology study, 435 were found to have atrioventricular nodal re-entry tachycardia (AVNRT) as underlying mechanism and 391 were having accessory pathway responsible for the reentry mechanism; of these accessory mediated tachycardia, 250 patients were manifested accessory pathway (WPWS); 141 were concealed accessory pathway (out of them 365 were presented with orthodromic and 26 as antidromic reciprocating tachycardia); moreover among the accessory pathway 231 patients were found having left sided accessory pathway whereas 155 having right sided pathway; 12 patients were having focal atrial tachycardia and 4 were found atrial flutter as the underlying cause for SVT. Radiofrequency catheter ablation was used with an overall success rate of 95%, recurrence rate of 2% without any significant complication. Complication: One patient developed pulmonary thrombo-embolism, 6 patients developed DVT of right lower limb, 4 patients developed complete heart block. Conclusion: RF catheter ablation is safe and highly effective mode of treatment of different types of supraventricular tachyarrhythmias which is emerging and becoming popular in our country. Bangladesh Heart Journal 2021; 36(2): 68-73

Association of age with clinical features and ablation outcomes of paroxysmal supraventricular tachycardias

ObjectiveThe role of age in clinical characteristics and catheter ablation outcomes of atrioventricular nodal re-entrant tachycardia (AVNRT) or orthodromic atrioventricular re-entrant tachycardia (AVRT) has been assessed in retrospective studies categorising age by arbitrary cut-offs, but contemporary analyses of age-related trends are lacking. We aimed to study the relationship of age with epidemiological, clinical features and catheter ablation outcomes of AVNRT and AVRT.MethodsWe recruited 600 patients (median age 56 years, 60% female) with a confirmed diagnosis of AVNRT (n=455) or AVRT (n=145) by means of an electrophysiological study. They were interrogated for arrhythmia-related symptoms with a structured questionnaire and followed up to 1 year. We analysed age as a continuous variable using regression models and adjusting for relevant covariables.ResultsBoth typical and atypical forms of AVNRT upraised with age while AVRT decreased (p<0.001 by regression). Female sex predominance in AVNRT was not observed in older patients. Overall, these tachycardias became more symptomatic with ageing despite a longer tachycardia cycle length (p<0.001) and regardless of the presence of structural heart disease, with a higher proportion of dizziness, syncope, chest pain or dyspnoea (p<0.005 for all) and a lower presence of palpitations or neck pounding (p<0.001 for both). Age was not associated with catheter ablation acute success, periprocedural complications or 1-year recurrence rates (p>0.05 for all).ConclusionsAge, evaluated as a continuous variable, had a significant association with the clinical profile of patients with AVNRT and AVRT. Nevertheless, catheter ablation outcomes and complications were not significantly related to patients’ age.

Importance of the Activation Sequence of the His or Right Bundle for Diagnosis of Complex Tachycardia Circuits

In this review, we emphasize the unique value of recording the activation sequence of the His bundle or right bundle branch (RB) for diagnoses of various supraventricular and fascicular tachycardias. A close analysis of the His to RB (H-RB) activation sequence can help differentiate various forms of supraventricular tachycardias, namely atrioventricular nodal reentry tachycardia from concealed nodofascicular tachycardia, a common clinical dilemma. Furthermore, bundle branch reentry tachycardia and fascicular tachycardias often are included in the differential diagnosis of supraventricular tachycardia with aberrancy, and the use of this technique can help the operator make the distinction between supraventricular tachycardias and these other forms of ventricular tachycardias using the His-Purkinje system. We show that this technique is enhanced by the use of multipolar catheters placed to span the proximal His to RB position to record the activation sequence between proximal His potential to the distal RB potential. This allows the operator to fully analyze the activation sequence in sinus rhythm as compared to that during tachycardia and may help target ablation of these arrhythmias. We argue that 3 patterns of H-RB activation are commonly identified—the anterograde H-RB pattern, the retrograde H-RB (right bundle to His bundle) pattern, and the chevron H-RB pattern (simultaneous proximal His and proximal RB activation)—and specific arrhythmias tend to be associated with specific H-RB activation sequences. We show that being able to record and categorize this H-RB relationship can be instrumental to the operator, along with standard pacing maneuvers, to make an arrhythmia diagnosis in complex tachycardia circuits. We highlight the importance of H-RB activation patterns in these complex tachycardias by means of case illustrations from our groups as well as from prior reports.

Arrhythmias Other Than Atrial Fibrillation in Those With an Irregular Pulse Detected With a Smartwatch: Findings From the Apple Heart Study

Background: The Apple watch irregular pulse detection algorithm was found to have a positive predictive value of 0.84 for identification of atrial fibrillation (AF). We sought to describe the prevalence of arrhythmias other than AF in those with an irregular pulse detected on a smartwatch. Methods: The Apple Heart Study investigated a smartwatch-based irregular pulse notification algorithm to identify AF. For this secondary analysis, we analyzed participants who received an ambulatory ECG patch after index irregular pulse notification. We excluded participants with AF identified on ECG patch and described the prevalence of other arrhythmias on the remaining participant ECG patches. We also reported the proportion of participants self-reporting subsequent AF diagnosis. Results: Among 419 297 participants enrolled in the Apple Heart Study, 450 participant ECG patches were analyzed, with no AF on 297 ECG patches (66%). Non-AF arrhythmias (excluding supraventricular tachycardias <30 beats and pauses <3 seconds) were detected in 119 participants (40.1%) with ECG patches without AF. The most common arrhythmias were frequent PACs (burden ≥1% to <5%, 15.8%; ≥5% to <15%, 8.8%), atrial tachycardia (≥30 beats, 5.4%), frequent PVCs (burden ≥1% to <5%, 6.1%; ≥5% to <15%, 2.7%), and nonsustained ventricular tachycardia (4–7 beats, 6.4%; ≥8 beats, 3.7%). Of 249 participants with no AF detected on ECG patch and patient-reported data available, 76 participants (30.5%) reported subsequent AF diagnosis. Conclusions: In participants with an irregular pulse notification on the Apple Watch and no AF observed on ECG patch, atrial and ventricular arrhythmias, mostly PACs and PVCs, were detected in 40% of participants. Defining optimal care for patients with detection of incidental arrhythmias other than AF is important as AF detection is further investigated, implemented, and refined.

Supraventricular tachycardia: modern methods of diagnosis and treatment (мethodical recommendations)

Methodical recommendations are devoted to one of the most pressing problems of cardiology – paroxysmal heart rhythm disorders in clinical practice. The recommendations consider the basic principles of determining supraventricular tachycardias (SVT) and their electrophysiological mechanisms. The clinic and features of ECG diagnostics of separate forms of tachycardias are stated. Emergency care and long-term therapy for SVT with narrow and wide QRS complexes are presented. Methods of treatment and algorithms for the management of patients with SVT in accordance with the updated in 2019 recommendations of the European Association of Cardiologists for the management of patients with SVT, antiarrhythmic drugs and their use, the principles of catheter treatment of tachycardia. Recommendations are addressed to cardiologists, therapists, doctors of functional diagnostics, general practitioners and family medicine, interns.

A case report of a patient with wide complex tachycardia due to Wolff–Parkinson–White syndrome mimicking ventricular tachycardia

Background Wide complex tachycardia (WCT) associated with syncope as manifestation of an underlying, life-threatening arrhythmia might potentially be the harbinger of sudden cardiac death. Identifying the aetiology of a WCT is imperative to provide appropriate treatment and prevent recurrence. Case summary We report the case of a 22-year-old male who had been experiencing haemodynamically significant WCT leading to syncope at the age of 13 years. As the patient and the family rejected an electrophysiological (EP) study, he had received an implantable cardioverter-defibrillator (ICD) for secondary prevention. After 7 years of experiencing multiple shocks, the patient finally gave consent to an EP study, which identified a left-sided accessory atrioventricular pathway that was successfully ablated during the same procedure. Discussion The differential diagnosis of WCT might be challenging and includes both ventricular and supraventricular tachycardias. In young patients without structural heart disease experiencing WCT, an EP study should be offered before ICD implantation to make a final diagnosis with the potential to provide definitive treatment.

Utilizing the Cool-Down Phenomenon to Differentiate Supraventricular Tachycardias in a Patient with COVID-19 Infection

A 63-year-old male patient with a history of hypertension, diabetes mellitus type 2, prostate cancer and class two obesity was admitted for encephalopathy. During his hospital stay he developed narrow complex tachycardia and it was difficult to definitively diagnose the underlying arrhythmia. Observation of the cool down phenomenon on telemetry strip allowed us to make the diagnosis of atrial tachycardia and elegantly rule out other causes. We report this interesting case of narrow complex tachycardia.