Can transesophageal echocardiography be safely omitted in patients scheduled for elective ablation of atrial arrhythmias? Data based on the LATTEE registry.

BACKGROUND: According to the present guidelines, transesophageal echocardiography (TEE) before scheduled catheter ablation (CA) for atrial arrhythmias (atrial fibrillation [AF] or atrial flutter [AFL]) is not deemed obligatory for optimally anticoagulated patients. However, daily clinical practice significantly differs from the recommendations. AIMS: We aimed to identify transthoracic echocardiographic parameters that could be useful in identifying patients without left atrial thrombus (LAT), which makes it possible to avoid unnecessary TEE before scheduled CA. METHODS: This is a sub-analysis of a multicenter, prospective, observational study - the LATTEE registry. A total of 1346 patients referred for TEE before scheduled CA of AF/AFL were included. RESULTS: LAT was present in 44 patients (3.3%) and absent in the remaining 1302, who were younger, more likely to have paroxysmal AF, and displayed sinus rhythm during TEE. Additionally, they exhibited a lower incidence of heart failure, diabetes, systemic connective tissue disease, and chronic obstructive pulmonary disease. Furthermore, they had a lower CHA2DS2-VASc score and a higher prevalence of direct oral anticoagulants. Echocardiographic parameters, including left ventricular ejection fraction (LVEF) >65%, left atrial diameter (LAD) <40 mm, left atrial area (LAA) <20 cm2, left atrial volume (LAV) <113 ml, and left atrial volume index (LAVI) <51 ml/m2, demonstrated 100% sensitivity and 100% negative predictive value for the absence of LAT and were met by 417 patients. Additional echocardiographic indices: LVEF/LAD ≥1.4, LVEF/LAVI ≥1.6, and LVEF/LAA ≥2.7 identified 57 additional patients, bringing the total of predicted LAT-free patients to 474 (35%). CONCLUSIONS: Simple echocardiographic parameters could help identify individuals for whom TEE could be safely omitted before elective CA due to atrial arrhythmias.

Clinical and Laboratory Predictors of Long-Term Outcomes after Catheter Ablation for a Ventricular Electrical Storm.

Background: Ventricular electrical storm (VES) is characterized by the occurrence of multiple episodes of sustained ventricular arrhythmias (VA) over a short period of time. Radiofrequency ablation (RFA) has been reported as an effective treatment in patients with ventricular tachycardia (VT). Objective: The aim of the present study was to indicate the short-term and long-term predictors of recurrent VA after RFA was performed due to VES. Methods: A retrospective, single-centre study included patients, who had undergone RFA due to VT between 2012 and 2021. In terms of the short-term (at the end of RFA) effectiveness of RFA, the following scenarios were distinguished: complete success: inability to induce any VT; partial success: absence of clinical VT; failure: inducible clinical VT. In terms of the long-term (12 months) effectiveness of RFA, the following scenarios were distinguished: effective ablation: no recurrence of any VT; partially successful ablation: VT recurrence; ineffective ablation: VES recurrence. Results: The study included 62 patients. Complete short-term RFA success was obtained in 77.4% of patients. The estimated cumulative VT-free survival and VES-free survival were, respectively, 28% and 33% at the 12-month follow-up. Ischemic cardiomyopathy and complete short-term RFA success were predictors of long-term RFA efficacy. Neutrophil to lymphocyte ratio (NLR) and GFR <60 mL/min/1.73 m2 were associated with VES recurrence. NLR ≥2.95 predicted VT and/or VES recurrence with a sensitivity of 66.7% and specificity of 72.2%. Conclusion: Ischemic cardiomyopathy and short-term complete success of RFA were predictors of no VES recurrence during the 12-month follow-up, while NLR and GFR <60 ml/min/1.73 m2 were associated with VES relapse.

Real-Life Inter-Rater Variability of the PRAETORIAN Score Values.

(1) Background: The PRAETORIAN score is a tool developed for postoperative evaluation of the position of subcutaneous implantable cardioverter-defibrillator systems. The aim of our study was to evaluate the real-life inter-rater variability of the PRAETORIAN score, based on chest radiographs of S-ICD patients reviewed by independent clinical raters. (2) Methods: Postoperative chest X-rays of patients that underwent S-ICD implantation were evaluated by five clinical raters who gave values of the PRAETORIAN score. Ratings were then compared in a fully crossed manner to determine the inter-rater variability of the attributed scores. (3) Results: In total, 87 patients were included in the study. In the case of the most important final risk category of the PRAETORIAN score, the mean Light's kappa was 0.804, the Fleiss' kappa was 0.249, and the intraclass correlation was 0.38. The final risk category was identically determined by all five raters in 75.86% of patients, by four raters in 14.94%, and by three raters in 9.20% of patients. (4) Conclusions: The overall inter-rater variability of the PRAETORIAN score in a group of electrophysiologists experienced in S-ICD implantation, yet previously naive to the PRAETORIAN score, and self-trained in its utilization, was only modest in our study. Appropriate use of the score might require training of clinical raters.

Right Ventricular Endocardial Mapping and a Potential Arrhythmogenic Substrate in Cardiac Amyloidosis-Role of ICD.

Patients with cardiac amyloidosis (CA) have an increased risk of sudden cardiac death. (SCD). However, the role of an implantable cardioverter-defibrillator in the primary prevention of SCD in this group of patients is still controversial. We present a case with CA with recurrent syncope and non-sustained ventricular tachycardia. In order to further stratify the risk of SCD, an electrophysiological study with endocardial electroanatomic voltage mapping was performed prior to the ICD placement.

Successful Catheter Ablation of the "R on T" Ventricular Fibrillation.

In patients with idiopathic ventricular fibrillation (VF), recurrent implantable cardioverter-defibrillator (ICD) shocks might increase mortality risk and reduce patients' quality of life. Catheter ablation of triggering ectopic beats is considered to be an effective method. We present a patient with recurrent VF, caused by the "R on T" premature ventricular complexes. In the presented case radiofrequency catheter ablation efficiently eliminated arrhythmia trigger, which was possible to detect thanks to the intracardiac electrocardiograms (ECG's) stored in the ICD.

Long-term results of irrigated bipolar radiofrequency ablation in patients with recurrent arrhythmia after failed unipolar ablation.

INTRODUCTION: The RF ablation of ventricular tachycardia (VT) or atrial flutter (AFl) can be unsuccessful due to lack of lesion transmurality. Bipolar ablation (BA) is more successful than unipolar ablation (UA). The purpose of our study was to investigate the long-term effect of BA ablation in patients after failed UA. METHODS: Patients with septal VT (5) or AFL (2) after 2 to 5 unsuccessful UA were prospectively analysed after BA. All patients presented with heart failure or had ICD interventions. RESULTS: BA was successful in 5 patients (1 failure each in the AFL and VT group). The follow-up duration was 10 to 26 months. In AFL group, BA was successful in 1 patient, unidirectional cavotricuspid block in was achieved in the other patient. All patients were asymptomatic for 12 months, but 1 had atrial fibrillation and the other had AFL reablation 19 months after BA. In VT group, all patients had several forms of septal VT. BA was successful in 4 patients. In 2 patients with high septal VT BA resulted in complete atrioventricular block. During follow-up, 1 patient had VT recurrence 26 months after BA and died after an unsuccessful reablation. Three patients had VT recurrences of different morphologies, which required reablation (UA in 2 and alcohol septal ablation in the other patient). CONCLUSION: BA was successful in patients with AFL and septal VT resistant to standard ablation. Relapses of clinical arrhythmia are rare; however, long-term follow-up is complicated by recurrences of different arrhythmias related to complex arrhythmogenic substrate.

Echocardiographic predictors of atrial fibrillation recurrence after catheter ablation: A literature review.

BACKGROUND: Catheter ablation (CA) is a well-known treatment option for patients with symptomatic drug-resistant atrial fibrillation (AF). Multiple factors have been identified to determine AF recurrence after CA, however their predictive value is rather small. Identification of novel predictors of CA outcome is therefore of primary importance to reduce health costs and improve long-term results of intervention. The recurrence of AF following CA is related to severity of left ventricular (LV) dysfunction, extent of atrial dilatation and fibrosis. The aim of this paper was to present and discuss the latest studies on the utility of echocardiographic parameters in terms of CA effectiveness in patients with paroxysmal and persistent AF. METHODS: PubMed, Google Scholar, EBSCO databases were searched for studies reporting echocardiographic preprocedural predictors of AF recurrence after CA. LV systolic and diastolic function, as well as atrial size, strain and dyssynchrony were taken into consideration. RESULTS: Twenty one full-text articles were analyzed, including three meta-analyses. Several echocardiographic parameters have been reported to determine a risk of AF recurrence after CA. There are conventional methods that measure left atrial size and volume, LV ejection fraction, parameters assessing LV diastolic dysfunction, and methods using more innovative technologies based on speckle tracking echocardiography to determine left atrial synchrony and strain. Each of these parameters has its own predictive value. CONCLUSIONS: Regarding CA effectiveness, every patient has to be evaluated individually to estimate the risk of AF recurrence, optimally using a combination of several echocardiographic parameters.

Echocardiographic assessment in patients with atrial fibrillation (AF) and normal systolic left ventricular function before and after catheter ablation: If AF begets AF, does pulmonary vein isolation terminate the vicious circle?

BACKGROUND: Radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) can be curative. There are conflicting data on whether AF associated atrial and ventricular structural remodeling reverses after ablation. The aim of this study was to evaluate the hemodynamic effect of AF ablation in patients with preserved left ventricular ejection fraction (LVEF). METHODS: Forty three AF patients were studied (aged 56 ± 11 years; 29 male, 23% persistent AF, LVEF ≥ 50%) in whom RFCA was performed. Echocardiographic evaluation of atrial and ventricular diameters, volumes and strain imaging by two-dimensional speckle tracking were performed before and at least 6 months after RFCA. Nine patients had AF during baseline examination. RESULTS: A significant decrease in the left (LA) and right (RA) atrial volume and an increase in the LA strain were observed 15 ± 7 months after RFCA. In the subgroup with baseline sinus rhythm, the increment in LA strain was only borderline significant. An increase in RA, right ventricular (RV) and Biatrial strain was noticed (p < 0.05). LVEF and global longitudinal strain of the left ventricle (LV), however, did not improve substantially. CONCLUSIONS: Radiofrequency catheter ablation of AF in patients with preserved LV systolic function results in significant improvement in RA and RV function with a substantial reduction in LA and RA size. No deleterious impact of AF ablation on LA function was revealed.

Polish single-centre follow-up of subcutaneous implantable cardioverter-defibrillator (S-ICD) systems implanted for the prevention of sudden cardiac death.

BACKGROUND AND AIM: Subcutaneous implantable cardioverter-defibrillator (S-ICD) is an effective and modern tool used to protect patients at risk of sudden cardiac death (SCD) from potentially life-threatening ventricular arrhythmias. The first S-ICD systems were implanted in Poland in 2014, but since that time the national experience with that therapy has been limited. Our analysis summarises the single-centre experience at the Department of Cardiology and Electrotherapy of the Medical University of Gdansk with the use of S-ICD from the year 2014 to 2017. METHODS AND RESULTS: The S-ICD therapy was used in 12 patients (five male, seven female, mean age 57.2 ± 12.5 years), in eight of them for the secondary prevention of SCD. No surgical complications of implantation procedures were observed during the perioperative hospitalisation nor during follow-up. During the mean follow-up of 14 ± 13 months we observed the appropriate function of the systems and a ventricular fibrillation episode successfully terminated by the device in one patient, two cases of S-ICD sensing problems (one of which led to inadequate intervention of the device), and an episode of atrial fibrillation also leading to inadequate intervention in another patient. CONCLUSIONS: S-ICD, being an effective and safe method used to treat patients at risk of SCD, may be safely and successfully introduced into clinical practice in centres new to that field. The number of complications during the initial experience and introduction of that method may be kept low if the operating team is experienced enough in cardiac electrotherapy.

Pre-discharge defibrillation testing: Is it still justified?

BACKGROUND: An implantable cardioverter-defibrillator (ICD) is routinely used to prevent sudden cardiac death. Since the introduction of that device into clinical practice, a defibrillation test (the so-called pre-discharge test [PDT]) has been an inseparable part of the ICD implantation procedure. Recently, the usefulness of PDT has been called into question. METHODS: The aim of this research was to analyze ICD tests performed within two time periods: in years 1995-2001 (period I) and 2007-2010 (period II), in order to compare the results of tests and solutions to all the problems with ICD systems revealed by means of PDT. RESULTS: During period I, 193 tests were performed, among which the ICD system malfunction was observed in 16 cases. Those included: sensing issues, specifically R-wave undersensing during ventricular fibrillation (VF) (7 patients) and T-wave oversensing (4 patients), as well as high defibrillation threshold (DFT) (2 patients) and ICD-pacemaker interaction (3 patients). During period II, among 561 tests, system malfunction was observed in 15 cases. In 1 patient it was VF undersensing, and in the remaining 14 it was high DFT. All the above problems were solved by means of appropriate ICD reprogramming, repositioning of the endocardial defibrillation lead or implantation of an additional subcutaneous defibrillation lead. CONCLUSIONS: Contemporary ICD technical solutions, compared to older systems, in most cases allow to avoid sensing problems. The key rationale behind ICD testing is the ability to confirm the efficacy of high-voltage therapy. Despite the increasing maximal defibrillation out-put of devices, and all possible adjustments to the characteristics of the impulse, there is still a group of patients that require additional procedures to ensure the appropriate defibrillation efficacy.

Implantation of additional subcutaneous array electrode reduces defibrillation threshold in ICD patients - preliminary results.

INTRODUCTION: Among the recipients of implantable cardioverter-defibrillators (ICDs), there is a group of patients in whom the defibrillation threshold (DFT) is too high to enable a sufficient safety margin between the DFT and the maximal available output of the device. The aim of the study was to investigate the ability of an additionally implanted single-coil subcutaneous array electrode to reduce the DFT in such patients. MATERIAL AND METHODS: Medtronic 6996SQ electrode was implanted in 15 patients selected from our follow-up group of 741 ICD patients: 10 of them had insufficient post-implant DFT safety margin, and 5 had ineffective first maximal energy shock as recorded by the device. In 6 cases the patients had CRT-D devices, in 5 cases - dual-chamber ICDs, and in 4 cases - single-chamber ICDs. In all patients but one the defibrillating electrode was single-coil. In one patient it was dual-coil. The underlying disease was coronary artery disease in 10 patients, dilated cardiomyopathy in 4 patients and hypertrophic cardiomyopathy in 1 patient. RESULTS: The subcutaneous electrode was successfully implanted in all the patients qualified for the procedure. No technical issues or perioperative complications were observed. Mean DFT was reduced from 33.3 ±4.1 J before the procedure to 25.3 ±4.4 J after the implantation procedure (p < 0.01). CONCLUSIONS: Our results show that the use of a single-coil subcutaneous electrode to reduce the DFT is a safe and effective procedure. Further studies are necessary to confirm these results.