Characteristics of a large-scale cohort with accessory pathway(s): A cross-sectional retrospective study highlighting over a twenty-year experience.

OBJECTIVE: Catheter ablation following electrophysiologic study (EPS) is the mainstay of diagnosis and treatment for patients with atrioventricular reentrant tachycardia (AVRT), demonstrating excellent long-term outcome and a low rate of complications. In this study, our aim was to assess our experience in patients with accessory pathway (AP) and to compare our data with the literature. METHODS: We included 1,437 patients who were diagnosed and treated for AP in our hospital between 1998 and 2020. The demographic data of all the patients, AP location, and periprocedural results were recorded. RESULTS: Of the 1,437 patients, 1,299 (90.4%) were men; and the mean age of the population was 26.67 years. The location of 1,418 APs were along the left free wall (647 [45.6%] patients), in the posteroseptal region (366 [25.3%] patients), in the anteroseptal region (290 [20.4%] patients), and along the right free wall (115 [8.1%] patients). The ratio of the second AP existence was 3.0% and AVNRT co-existence was 2.0%. A total of 55 (3.8%) patients had recurrent sessions for relapse. Our center's total success rate was 95.5%, and total complication rate was 0.26%. CONCLUSION: According to our retrospective analysis, EPS is a highly functional tool in the diagnosis and management of arrhythmias such as AVRT for high-risk patient groups like military personnel with the aim of risk stratification and medical management.

Management of supraventricular arrhythmias in adults with congenital heart disease.

Supraventricular arrhythmias are a frequent complication in adults with congenital heart disease (ACHD). The prevalence increases with time since surgery, complexity of the underlying defect, type of repair and older age at surgery. Arrhythmias are the most frequent reason for hospital admission and along with heart failure the leading cause of death. The arrhythmia-associated increase in morbidity and mortality makes their management a key task in patients with ACHD. Intra-atrial re-entry is the most frequent arrhythmia mechanism. Less common arrhythmia mechanisms are supraventricular tachycardias in the presence of an accessory pathway, atrioventricular nodal re-entrant tachycardia or focal tachycardias. Patient management includes stroke prevention, acute termination and prevention of arrhythmia recurrence. Acute treatment depends on patients' symptoms. In cases of haemodynamic instability, immediate cardioversion is warranted. For stable patients, acute treatment includes rate control and termination by antiarrhythmic drugs or electrical cardioversion. Following a symptomatic arrhythmia, catheter ablation or treatment with antiarrhythmic drugs is recommended to prevent recurrences. Advances in mapping and ablation technology are now associated with high success rates of catheter ablation. In patients with a complex substrate recurrence rates of 50% remain high. However, in the presence of side effects and complications associated with long-term antiarrhythmic drug therapy, redo procedures are encouraged by current guidelines.

Differentiating junctional tachycardia and atrioventricular node re-entry tachycardia based on response to atrial extrastimulus pacing.

OBJECTIVES: The purpose of this study was to differentiate non-re-entrant junctional tachycardia (JT) and typical atrioventricular node re-entry tachycardia (AVNRT). BACKGROUND: JT may mimic AVNRT. Ablation of JT is associated with a lower success rate and a higher incidence of heart block. Electrophysiologic differentiation of these tachycardias is often difficult. METHODS: We hypothesized that JT can be distinguished from AVNRT based on specific responses to premature atrial complexes (PACs) delivered at different phases of the tachycardia cycle: when a PAC is timed to His refractoriness, any perturbation of the subsequent His indicates that anterograde slow pathway conduction is involved and confirms a diagnosis of AVNRT. A PAC that advances the His potential immediately after it without terminating tachycardia indicates that retrograde fast pathway is not essential for the circuit and confirms a diagnosis of JT. This protocol was tested in 39 patients with 44 tachycardias suggesting either JT or AVNRT based on a short ventriculo-atrial interval and apparent AV node dependence. Tachycardias were divided into 3 groups: clinically obvious AVNRT, clinically obvious JT, and clinically indeterminate rhythm. RESULTS: In the 26 cases of clinically obvious AVNRT, the sensitivity and specificity of the test were 61% and 100%, respectively. In the 9 cases of clinically obvious JT, the sensitivity and specificity were 100% and 100%, respectively. In the 9 cases of clinically indeterminate rhythm, the technique indicated AVNRT in 1 patient and JT in 7 patients, and the test was indeterminate in 1 patient. CONCLUSIONS: The response to PACs during tachycardia can distinguish JT and AVNRT with 100% specificity in adult patients.

Outcome of symptomatic patients undergoing extracardiac Fontan conversion and cryoablation.

OBJECTIVE: We review our experience with Fontan conversion and cryoablation in patients with an atriopulmonary Fontan in low cardiac output from arrhythmia or venous obstruction, including 2 patients with protein-losing enteropathy. METHODS: Ten patients (mean age 21.1 +/- 7.0 years) underwent extracardiac Fontan conversion, cryoablation, and pacemaker placement between November 1999 and April 2002 (13.1 +/- 4.1 years after the original atriopulmonary connection). Eight patients were in New York Heart Association class III and 2 were in New York Heart Association class IV. Nine patients had clinically important intra-atrial reentry tachycardia refractory to medical therapy. RESULTS: Follow-up was between 3.1 and 32.6 months (16.8 +/- 9). One death occurred at 7 days after surgery due to sepsis and multisystem organ failure. The second death occurred at 48 days from complications of protein-losing enteropathy. The second patient with protein-losing enteropathy had improved New York Heart Association classification, cessation of albumin transfusions, and a normal stool alpha antitrypsin level (down from 4.1 mg/g preoperatively). Five patients improved to New York Heart Association class I and 3 patients to New York Heart Association class II. Sustained arrhythmias could not be induced in any patient. Seven patients are on no antiarrhythmics. One patient had recurrence of intra-atrial reentrant tachycardia 11 months postoperatively, which required electrical cardioversion; this patient's symptoms are currently well controlled on 1 medication. CONCLUSION: Extracardiac Fontan, cryoablation, and pacemaker placement reduced atrial arrhythmias and improved New York Heart Association classification in all surviving patients. In selected patients, this operation offers improvement in clinical outcome and is an alternative to transplantation. Protein-losing enteropathy may not be a contraindication to performing Fontan conversion with cryoablation.