Diagnosis and management of typical atrial flutter

Intracardiac Echocardiography Guidance Improves Procedural Outcomes in Patients Undergoing Cavotricuspidal Isthmus Ablation for Typical Atrial Flutter

Atrial flutter (AFL) represents a prevalent variant of supraventricular tachycardia, distinguished by a macro-reentrant pathway encompassing the cavotricuspid isthmus (CTI). Radiofrequency (RF) catheter ablation stands as the favored therapeutic modality for managing recurring CTI-dependent AFL. Intracardiac echocardiography (ICE) has been proposed as a method to reduce radiation exposure during CTI ablation. This study aims to comprehensively compare procedural parameters between ICE-guided CTI ablation and fluoroscopy-only procedures. A total of 370 consecutive patients were enrolled in our single-center retrospective study. In 151 patients, procedures were performed using fluoroscopy guidance only, while 219 patients underwent ICE-guided CTI ablation. ICE guidance significantly reduced fluoroscopy time (73 (36; 175) s vs. 900 (566; 1179) s; p < 0.001), fluoroscopy dose (2.45 (0.6; 5.1) mGy vs. 40.5 (25.7; 62.9) mGy; p < 0.001), and total procedure time (70 (52; 90) min vs. 87.5 (60; 102.5) min; p < 0.001). Total ablation time (657 (412; 981) s vs. 910 (616; 1367) s; p < 0.001) and the time from the first to last ablation (20 (11; 36) min vs. 40 (25; 55) min; p < 0.01) were also significantly shorter in the ICE-guided group. Acute success rate was 100% in both groups, and no major complications occurred in either group. ICE-guided CTI ablation in patients with AFL resulted in shorter procedure times, reduced fluoroscopy exposure, and decreased ablation times, compared to the standard fluoroscopy-only approach.

Ablation of intra-atrial reentrant tachycardias in adults with congenital heart disease: islands, isthmuses, channels, and walls

PURPOSE OF REVIEW

The adult congenital heart patient population is rapidly growing due to increasing survival rates, and they often face chronic physiologic challenges as sequalae of both their defects and repairs. Among the most common sequalae are arrhythmias. Here we describe intra-atrial reentrant tachycardia (IART), one of the most commonly seen arrhythmias in the adult congenital heart population, and the approaches to successful ablation in adult congenital heart patients.

RECENT FINDINGS

IART has increasing ablation success rates due to the increasing exposure of electrophysiologists to congenital cases, advances in technology, and the increasing application of both our pediatric congenital knowledge and adult acquired knowledge to the adult congenital population.

SUMMARY

IART is a frequently seen arrhythmia in the adult congenital population, and it can have life-threatening consequences in the setting of congenital disease. Ablation techniques and treatment rates have improved over time, despite the challenges these cases present to clinicians; success of the ablation depends on careful, often creative, preplanning, and understanding of the complex individualized anatomy and circuits of the patient.

Ablation Therapy as Management of Typical Atrial Flutter in the Early Period After Cardiac Surgery

Introduction

Available data on management of atrial flutter in the early postoperative setting after cardiac surgery are scarce. We aimed to investigate the safety and efficacy (profile) of flutter ablation in the early postoperative phase (30 days after cardiac surgery) in a cohort of 47 consecutive patients.

Methods

Between 2007 and 2016, 47 patients who underwent ablation for postoperative typical atrial flutter were retrospectively identified and analyzed. Follow-up data were acquired from patients’ records in case of rehospitalization and via follow-up calls.

Results

The median age of patients was 69 years, 89% male and with a median LV-EF of 55%. CAD was present in 80.8% of patients. The predominant conduction of atrial flutter was 2:1 (76.6%); 85.1% of patients had either undergone CABG, SAVR, or a combination of these two. Acute procedural success could be achieved in 100% of patients with one vascular pseudoaneurysm that was managed conservatively. No other complications occurred. After a median follow-up of 5.7 years, follow-up information regarding heart rhythm was available in 87.2% of patients. One patient (2.1%) had undergone repeat ablation for typical flutter. Two patients (4.2%) had developed atrial fibrillation, while 87.2% of patients were in sinus rhythm.

Conclusions

In this small cohort, early postoperative ablation of typical flutter was associated with a favorable short- and long-term safety and efficacy profile and can be considered part of heart rhythm management options in this setting.

Poincaré Plot Image and Rhythm-Specific Atlas for Atrial Bigeminy and Atrial Fibrillation Detection

A detector based only on RR intervals capable of classifying other tachyarrhythmias in addition to atrial fibrillation (AF) could improve cardiac monitoring. In this paper a new classification method based in a 2D non-linear RRI dynamics representation is presented. For this aim, the concepts of Poincaré Images and Atlases are introduced. Three cardiac rhythms were targeted: Normal sinus rhythm (NSR), AF and atrial bigeminy (AB). Three Physionet open source databases were used. Poincaré Images were generated for all signals using different Poincaré plot configurations: RR, dRR and RRdRR. The study was computed for different time window lengths and bin sizes. For each rhythm, the Poincaré Images of the 80% of that rhythm's patients were used to create a reference image, a Poincaré Atlas. The remaining 20% were used as test set and classified into one of the three rhythms using normalized mutual information and 2D correlation. The process was iterated in a tenfold cross-validation and patient-wise dataset division. Sensitivity results obtained for RRdRR configuration and bin size 40 ms, for a 60 s time window were 94.35% ±3.68, 82.07% ±9.18 and 88.86% ±12.79 with a specificity of 85.52% ±7.46, 95.91% ±3.14, 96.10% ±2.25 for AF, NSR and AB respectively. Results suggest that a rhythms general RRI pattern may be captured using Poincaré Atlases and that these can be used to classify other signal segments using Poincaré Images. In contrast with other studies, the former method could be generalized to more cardiac rhythms and does not depend on rhythm-specific thresholds.

Using the Virtual Heart Model to validate the mode-switch pacemaker operation

Artificial pacemakers are one of the most widely-used implantable devices today, with millions implanted worldwide. The main purpose of an artificial pacemaker is to treat bradycardia, or slow heart beats, by pacing the atrium and ventricles at a faster rate. While the basic functionality of the device is fairly simple, there are many documented cases of death and injury due to device malfunctions. The frequency of malfunctions due to firmware problems will only increase as the pacemaker operations become more complex in an attempt to expand the use of the device. One reason these malfunctions arise is that there is currently no methodology for formal validation and verification of medical device software, as there are in the safety-critical domains of avionics and industrial control automation. We have developed a timed-automata based Virtual Heart Model (VHM) to act as platform for medical device software validation and verification. Through a case study involving multiple arrhythmias, this investigation shows how the VHM can be used with closed-loop operation of a pacemaker to validate the necessity and functionality of the complex mode-switch pacemaker operation. We demonstrate the correct pacemaker operation, to switch from one rhythm management mode to another, in patients with supraventricular tachycardias. (1).