Bipolar catheter ablation with dedicated radiofrequency system for highly refractory ventricular arrhythmia-Does the rate of success depend on arrhythmia origin?

INTRODUCTION: Despite rapid technological progress, some arrhythmias are still resistant to standard unipolar ablation. These include arrhythmias arising from the base of the heart, cardiac crux, or epicardium. Bipolar radiofrequency ablation (B-RFA) may be useful in some cases, however, data on the efficacy of this approach in various arrhythmia localizations are scarce. The aim of this study was to assess the efficacy of B-RFA in patients with ventricular arrhythmias originating from various locations, occurring refractory to standard unipolar ablation approaches. METHODS: An observational, single center study was conducted over a 30-month period. B-RFA were performed using dedicated radio frequency (RF) generator and electroanatomic mapping system. RESULTS: Twenty-four procedures, in 23 patients with a median (range) of 1 (1-2) previously failed unipolar ablation procedures, were included in the final analysis. There were 12 ablations of ventricular arrhythmias originating from interventricular septum with an acute success rate of 75%, and 12 from left ventricular (LV) summit with an acute success rate of 58%. The midterm success rate (median interquartile range follow-up of 205 days [188-338]) was 66% and 50%, respectively. CONCLUSIONS: B-RFA is a promising method of catheter ablation for refractory cardiac arrhythmias. A higher success rate was observed in ablation for difficult ventricular arrhythmias originating from interventricular septal region than LV summit.

The Comparative Effectiveness and Safety of Different Anticoagulation Strategies for Treatment of Left Atrial Appendage Thrombus in the Setting of Chronic Anticoagulation for Atrial Fibrillation or Flutter.

PURPOSE: To compare effectiveness of different treatments for atrial fibrillation (AF) patients who were scheduled for cardioversion (CV) or ablation (CA) presenting with left atrium appendage (LAA) thrombus despite chronic oral anticoagulation therapy (OAC). METHODS: This was a retrospective cohort study. We analyzed 2014-2019 medical records of patients scheduled for CV or CA of AF who were diagnosed with LAA thrombus despite optimal OAC and had a follow-up transesophageal echocardiogram (TOE). Changes in treatment were divided into the following groups: switch to a drug with different mechanism of action, switch to a drug with similar mechanism of action, initiation of combination therapy, or deliberate no change in treatment. Patients with contraindications to non-vitamin K antagonists were excluded from the analysis. RESULTS: We analyzed data of 129 patients comprising 181 cycles of treatment. The overall effectiveness of LAA thrombus dissolution was 51.9% regardless of the number of cycles and 42.6% for the first cycle of treatment. Any change of treatment was more effective than deliberate no change-OR 2.97 [95% CI: 1.07-8.25], P = 0.031, but no particular strategy seemed to be more effective than the other. Left atrium area (OR 0.908 [95% CI: 0.842-0.979]) and number of treatment cycles (OR 0.457 [95% CI: 0.239-0.872]) were both adversely related to thrombus resolution. There was one ischemic and three bleeding adverse events during the treatment. CONCLUSION: LAA thrombus resolution in patients already on OAC may require a change of previous OAC treatment but the overall effectiveness of dissolution seems to be about 50%.

A quality of life, clinical and biochemical improvements after catheter ablation of persistent arrhythmia in patients with structural heart disease and arrhythmia-mediated cardiomyopathy.

BACKGROUND: Arrhythmia-mediated cardiomyopathy (AMC) is an essential clinical situation that is commonly underdiagnosed. Successful arrhythmia control leads to improvement in health-related quality of life (HRQoL) and heart failure (HF) symptoms in patients with structural heart disease (SHD). AIMS: The study aimed to evaluate the impact of catheter ablation (CA) of persistent arrhythmia on HRQoL, biochemical and clinical parameters HF in patients with SHD and AMC. METHODS: Patients with SHD, on optimal medical treatment, with persistent arrhythmia and strong suspicion of AMC, scheduled for CA were prospectively enrolled. Study procedures included: HRQoL measurement (the Minnesota Living with Heart Failure Questionnaire [MLHFQ] and the EuroQol Research Foundation [EQ-5D-3L] questionnaire), biomarkers (N-terminal pro-B-type natriuretic peptide [NT-proBNP], troponin T [TnT], matrix metalloproteinase-9 [MMP-9], soluble suppression of tumorigenesis-2 [sST2], tissue inhibitor of matrix metalloproteinase-1 [TIMP-1]), transthoracic echocardiography and clinical assessment. RESULTS: At 6 months, 30/35 (86%) patients were free of persistent arrhythmia. Patients who underwent successful CA had a significant improvement in HRQoL: MLHFQ (median [interquartile range, IQR], -22 [-28; -11]; P <0.001), EQ5D-3L score (mean [standard deviation], 21.8 (16.8); P <0.001); EQ5D-3L index (median [IQR], 0.09 (0.05; 0.18); P <0.001). A significant decrease in injury bio markers was observed: NT-proBNP (median [IQR], -414 [-1397; -318] pg/ml; P <0.001), TnT (median [IQR], -2.27 (-8.52; 0.55) ng/l; P <0.01) but not in fibrosis biomarkers: (median [IQR], sST2: 2.20 [-5.4; 4.3] ng/ml; P = 0.741, MMP-9: 34 [-376; 283] ng/ml; P = 0.881, TIMP-1: 11.1 [-17.1; 31.9] ng/ml; P = 0.215). There was a significant increase of left ventricular ejection fraction (LVEF) (mean [SD], 9.8 [5.9] %; P <0.01). CONCLUSIONS: Successful CA significantly improved clinical status, LVEF, and HRQoL of patients with SHD and AMC.

Rapid pharmacological cardioversion of recent-onset atrial fibrillation using antazoline in elderly patients.

INTRODUCTION: There is insufficient evidence on the efficacy and safety of pharmacological cardioversion of recent­onset atrial fibrillation (AF) in elderly patients. Antazoline has been shown to be effective and safe in various patient populations. OBJECTIVES: We aimed to compare the clinical efficacy and safety of intravenous antazoline for pharmacological cardioversion of recent­onset AF between patients aged 75 years or older and those younger than 75 years. PATIENTS AND METHODS: This retrospective analysis was conducted using data derived from emergency room medical records of patients referred for pharmacological cardioversion due to symptomatic AF lasting less than 48 hours. The threshold for old age was set at 75 years. Conversion to sinus rhythm was considered the primary efficacy outcome. The primary safety outcome was defined as any adverse event requiring hospitalization. RESULTS: The study included 334 participants, of whom 110 patients were aged 75 years or older (study group) and 224 patients were younger than 75 years (controls). Successful cardioversion was achieved using lower mean (SD) antazoline doses in the study group than in controls: 151 (59) mg vs 168 (58) mg (P = 0.039). Study and control groups showed a similar efficacy and safety of antazoline (78.2% and 68.3%, respectively; odds ratio [OR], 1.66; 95% CI, 0.98-1.31; P = 0.06) as well as hospitalization rates (0.9% and 4.0%, respectively; OR, 0.22; 95% CI, 0.03-1.75; P = 0.17). CONCLUSIONS: Intravenous antazoline seems to be effective and safe for pharmacological cardioversion of recent­onset AF in elderly patients in the emergency setting.