Factors predicting the progression from paroxysmal to persistent atrial fibrillation despite an index catheter ablation.

INTRODUCTION: Despite undergoing an index ablation, some patients progress from paroxysmal atrial fibrillation (PAF) to persistent AF (PersAF), and the mechanism behind this is unclear. The aim of this study was to investigate the predictors of progression to PersAF after catheter ablation in patients with PAF. METHODS: This study included 400 PAF patients who underwent an index ablation between 2015 and 2019. The patients were classified into three groups based on their outcomes: Group 1 (PAF to sinus rhythm, n = 226), Group 2 (PAF to PAF, n = 146), and Group 3 (PAF to PersAF, n = 28). Baseline and procedural characteristics were collected, and predictors for AF recurrence and progression were evaluated. RESULTS: The mean age of the patients was 58.4 ± 11.1 years, with 272 males. After 3 years of follow-up, 7% of the PAF cases recurred and progressed to PersAF despite undergoing an index catheter ablation. In the multivariable analysis, a larger left atrial (LA) diameter and the presence of non-pulmonary vein (PV) triggers during the index procedure independently predicted recurrence. Moreover, a larger LA diameter, the presence of non-PV triggers, and a history of thyroid disease independently predicted AF progression. CONCLUSION: The progression from PAF to PersAF after catheter ablation is associated with a larger LA diameter, history of thyroid disease, and the presence of non-PV triggers. Meticulous preprocedural evaluation, patient selection, and comprehensive provocation tests during catheter ablation are recommended.

Long-term mortality and cardiovascular outcomes in patients with atrial flutter after catheter ablation.

AIMS: For patients with typical and atypical atrial flutter (AFL) but without history of atrial fibrillation (AF), the long-term cardiovascular (CV) outcomes after catheter ablation for AFL remain unclear. We compared the long-term all-cause mortality and CV outcomes in patients with AFL receiving catheter ablation compared with the results with medical therapy. METHODS AND RESULTS: Atrial flutter patients receiving catheter ablation for typical AFL were identified using the Health Insurance Database, and constituted the 'AFL ablation group'. Patients with typical and atypical AFL but without ablation (AFL without ablation group) were propensity matched to the AFL ablation group. Patients with prior AF diagnosis were excluded. Primary outcomes included all-cause and CV mortality, heart failure (HF) hospitalization, and stroke. The multivariable cox hazards regression model was used to evaluate the hazard ratio (HR) for study outcomes. A total of 3784 AFL patients (1892 patients in each group) was studied. Their mean follow-up durations were 7.85 ± 2.57 years (AFL without ablation group) and 8.31 ± 4.53 years (AFL ablation group). Atrial flutter with ablation patients had lower risks of all-cause mortality (HR: 0.68, P < 0.001), CV deaths (HR: 0.78, P = 0.001), HF hospitalization (HR: 0.84, P = 0.01), and stroke (HR: 0.80, P = 0.01). CONCLUSIONS: Catheter ablation for AFL in patients without prior AF was associated with lower risks of all-cause mortality and CV events compared with AFL patients without ablation during long-term follow-ups.

Effects of phosphodiesterase-1 inhibitor on pulmonary vein electrophysiology and arrhythmogenesis.

INTRODUCTION: Phosphodiesterase (PDE) isoform inhibitors have mechanical and electrical effects on the heart. Inhibition of PDE-1 enzymes is a novel strategy for treating heart failure. However, the electrophysiological effects of PDE-1 inhibition on the heart remain unclear. This study explored the effects of PDE-1 inhibition using ITI-214 on electrical activity in the pulmonary vein (PV), the most common trigger of atrial fibrillation, and investigated the underlying ionic mechanisms. METHODS: Conventional microelectrodes or whole-cell patch clamps were employed to study the effects of ITI-214 (0.1-10 µM) on PV electrical activity, mechanical responses and ionic currents in isolated rabbit PV tissue specimens and isolated single PV cardiomyocytes. RESULTS: ITI-214 at 1 µM and 10 µM (but not 0.1 µM) significantly reduced PV spontaneous beating rate (10 ± 2% and 10 ± 3%, respectively) and PV diastolic tension (11 ± 3% and 17 ± 3%, respectively). ITI-24 (1 µM) significantly reduced late sodium current (INa-Late ), L-type calcium current (ICa-L ) and the reverse mode of the sodium-calcium exchanger (NCX), but it did not affect peak sodium currents. CONCLUSIONS: ITI-214 reduces PV spontaneous activity and PV diastolic tension by reducing INa-Late , ICa-L and NCX current. Considering its therapeutic potential in heart failure, targeting PDE-1 inhibition may provide a novel strategy for managing atrial arrhythmogenesis.

Case series on stereotactic body radiation therapy in non-ischemic cardiomyopathy patients with recurrent ventricular tachycardia.

INTRODUCTION: The efficacy of stereotactic body radiation therapy (SBRT) as an alternative treatment for recurrent ventricular tachycardia (VT) is still unclear. This study aimed to report the outcome of SBRT in VT patients with nonischemic cardiomyopathy (NICM). METHODS: The determination of the target substrate for radiation was based on the combination of CMR results and electroanatomical mapping merged with the real-time CT scan image. Radiation therapy was performed by Flattening-filter-free (Truebeam) system, and afterward, patients were followed up for 13.5 ± 2.8 months. We analyzed the outcome of death, incidence of recurrent VT, ICD shocks, anti-tachycardia pacing (ATP) sequences, and possible irradiation side-effects. RESULTS: A total of three cases of NICM patients with anteroseptal scar detected by CMR. SBRT was successfully performed in all patients. During the follow-up, we found that VT recurrences occurred in all patients. In one patient, it happened during a 6-week blanking period, while the others happened afterward. Re-hospitalization due to VT only appeared in one patient. Through ICD interrogation, we found that all patients have reduced VT burden and ATP therapies. All of the patients died during the follow-up period. Radiotherapy-related adverse events did not occur in all patients. CONCLUSIONS: SBRT therapy reduces the number of VT burden and ATP sequence therapy in NICM patients with VT, which had a failed previous catheter ablation. However, the efficacy and safety aspects, especially in NICM cases, remained unclear.

ABO Blood Groups as a Disease Marker to Predict Atrial Fibrillation Recurrence after Catheter Ablation.

Chronic inflammation harbors a vulnerable substrate for atrial fibrillation (AF) recurrence after catheter ablation. However, whether the ABO blood types are associated with AF recurrence after catheter ablation is unknown. A total of 2106 AF patients (1552 men, 554 women) who underwent catheter ablation were enrolled retrospectively. The patients were separated into two groups according to the ABO blood types, the O-type (n = 910, 43.21%) and the non-O-type groups (A, B, or AB type) (n = 1196, 56.79%). The clinical characteristics, AF recurrence, and risk predictors were investigated. The non-O type blood group had a higher incidence of diabetes mellitus (11.90 vs. 9.03%, p = 0.035), larger left atrial diameters (39.43 ± 6.74 vs. 38.20 ± 6.47, p = 0.007), and decreased left ventricular ejection fractions (56.01 ± 7.33 vs. 58.65 ± 6.34, p = 0.044) than the O-type blood group. In the non-paroxysmal AF (non-PAF) patients, the non-O-type blood groups have significantly higher incidences of very late recurrence (67.46 vs. 32.54%, p = 0.045) than those in the O-type blood group. The multivariate analysis revealed the non-O blood group (odd ratio 1.40, p = 0.022) and amiodarone (odd ratio 1.44, p = 0.013) were independent predictors for very late recurrence in the non-PAF patients after catheter ablation, which could be applied as a useful disease marker. This work highlighted the potential link between the ABO blood types and inflammatory activities that contribute to the pathogenic development of AF. The presence of surface antigens on cardiomyocytes or blood cells in patients with different ABO blood types will have an impactful role in risk stratification for AF prognosis after catheter ablation. Further prospective studies are warranted to prove the translational benefits of the ABO blood types for the patients receiving catheter ablation.

ECG characteristics of COVID-19 patient with arrhythmias: Referral hospitals data from Indonesia.

Background: Arrhythmia is a significant clinical modifier in COVID-19 patient outcomes. Currently, data on arrhythmia and ECG characteristics in COVID-19 from lower middle-income countries are limited. Methods: COVID-19 was confirmed by polymerase chain reaction testing of a nasopharyngeal sample. All clinical records were systematically evaluated to obtain demographic characteristics and medical comorbidities. The ECG was recorded on admission, in-hospital, and at discharge. Results: Total documented arrhythmia events account for 22% of patients, comprising 6% of new-onset arrhythmia and 16% of existing arrhythmia. Atrial fibrillation is the most common arrhythmia. The ECG changes were a decrease in heart rate (91 ± 22 vs. 83 ± 20, p < .001) and an increase in the QT interval (354.7 ± 53.70 vs. 371.4 ± 59.48 msec, p < .001) from hospital admission to hospital discharge, respectively. The in-hospital HR of 85 bpm or higher increases the risk of death (OR = 2.69, p = .019). Conclusion: The incidence of arrhythmias in COVID-19 patients at COVID-19 referral hospitals in Indonesia is 22%. Atrial fibrillation is the most common arrhythmia in COVID-19 patients. Prolongation of QRS duration from admission to discharge was related to the occurrence of new-onset arrhythmia. The in-hospital HR of 85 bpm or higher increased the risk of death.

Dynamic changes in signal-averaged P wave after catheter ablation of atrial fibrillation.

BACKGROUND: The comprehensive surveillance for interval changes in signal-averaged P-wave (SAPW) after pulmonary vein isolation (PVI) remains lacking. We aimed to analyze the SAPW parameters before and after PVI and explored their link to the left atrial electrical properties. METHODS: Eighteen patients with paroxysmal atrial fibrillation receiving primary catheter ablation were enrolled. SAPW parameters, including root mean square voltages in the last 40, 30, and 20 ms (RMS40, RMS30, and RMS20, respectively), the total P-wave (RMSt), the integral of P-wave potentials (Int-p), and P-wave duration (fPWD), were measured before and after PVI and correlated to the left atrial activation time (LAT) and mean left atrial voltage (LAV) from electro-anatomical mapping. RESULTS: Compared with the SAPW before PVI, fPWD (before vs after PVI: 144.1 ± 5.2 vs 135.1 ± 11.9 ms, p = 0.02), Int-p (687.4 ± 173.1 vs 559 ± 202.5 mVms, p = 0.01), and RMSt (6.44 ± 1.3 vs 5.44 ± 2.0 mV, p = 0.04) all decreased after PVI. RMS20, RMS30, and RMS40 showed no significant difference. Similarly, LAT (97.5 ± 9.3 vs 90.5 ± 9.3 ms, p = 0.008) and LAV (1.37 ± 0.27 vs 0.96 ± 0.31 mV, p = 0.001) decreased after PVI. Although consistent changes after PVI were observed between SAPW parameters and LAT or LAV, no linear correlation was observed among them. CONCLUSION: The consistent changes in SAPW and left atrial electrical properties after PVI suggest that SAPW may be used as a noninvasive tool to monitor the responses to PVI.

Left atrial appendage closure device implantation guided with fluoroscopy only: Long-term results.

BACKGROUND: Left atrial appendage (LAA) closure device is an alternative to anticoagulants for stroke prevention in selected atrial fibrillation (AF) patients. The LAA device implantation is safe with short period of learning curve. The standard implantation technique warrants a transesophageal echocardiography (TEE) guided and general anesthesia. In region of Asia Pacific as well as Indonesia, both TEE and general anesthesia are not always available in district hospital. We studied the safety and efficacy of Amplatzer Cardiac Plug (ACP) implantation guided by fluoroscopy only and without general anesthesia. METHODS: Consecutive nonvalvular AF patients with CHA2DS2VASc score of ≥2 and HASBLED score of ≥3 are participated. Patients requiring long-life anticoagulant for any other indication are excluded. The choice of implanted first or second-generation ACP is that with excess size of 2-4 mm of measured landing zone diameter. RESULTS: Twenty-five subjects were implanted ACP by means fluoroscopy only (Group A) and 28 subjects using standard technique group (Group B). The median AF duration was 36 months (6-276 months) and majority of patients (49%) are having permanent AF. The mean CHA2DS2VASc score is 3.9 ± 1.63. Successful implantation of ACPs was 96% in both groups. Nonfatal pericardial effusion occurred in three patients. During 75 weeks of follow-up period, there were no significant differences of stroke event and death between groups. CONCLUSION: ACP implantation guided with fluoroscopy only is feasible and safe.