Bailout Deep Septal LV Pacing to Treat Inadvertent Complete AV Block During Complex Ablation Procedure.

We present a case of persistent complete atrioventricular block that occurred during the diagnostic portion of a premature ventricular contractions' radiofrequency ablation in a complex heart failure patient. The case was managed by bailout deep left ventricular septal pacing after bipolar radiofrequency elimination of premature ventricular contractions.

Acute Kidney Injury Resulting From Hemoglobinuria After Pulsed-Field Ablation in Atrial Fibrillation: Is it Preventable?

BACKGROUND: High-voltage pulses can cause hemolysis. OBJECTIVES: The authors evaluated the occurrence of hemoglobinuria after pulsed-field ablation (PFA) and its impact on renal function in patients with atrial fibrillation (AF). METHODS: A consecutive series of patients with AF undergoing PFA were included in this analysis. The initial patients who did not receive postablation hydration immediately after the procedure were classified as group 1 (n = 28), and the rest of the study patients who received planned fluid infusion (0.9% sodium chloride ≥2 L) after the procedure were categorized as group 2 (n = 75). RESULTS: Of the 28 patients in group 1, 21 (75%) experienced hemoglobinuria during the 24 hours after catheter ablation. The mean postablation serum creatinine (S-Cr) was significantly higher than the baseline value in those 21 patients (1.46 ± 0.28 mg/dL vs 0.86 ± 0.24 mg/dL, P < 0.001). Of those 21 patients, 4 (19%) had S-Cr. >2.5 mg/dL (mean: 2.95 ± 0.21 mg/dL). The mean number of PF applications was significantly higher in those 4 patients than in the other 17 patients experiencing hemoglobinuria (94.63 ± 3.20 vs 46.75 ± 9.10, P < 0.001). In group 2 patients, no significant changes in S-Cr were noted. The group 2 patients received significantly higher amounts of fluid infusion after catheter ablation than did those in group 1 (2,082.50 ± 258.08 mL vs 494.01 ± 71.65 mL, P < 0.001). In multivariable analysis, both hydration (R2 = 0.63, P < 0.01) and number of PFA applications (R2 = 0.33, P < 0.01) were independent predictors of postprocedure acute kidney injury. CONCLUSIONS: On the basis of our findings, both the number of PFA applications and postablation hydration were independent predictors of renal insult that could be prevented using planned fluid infusion immediately after the procedure.

Pulsed-Field Ablation Does Not Worsen Baseline Pulmonary Hypertension Following Prior Radiofrequency Ablations.

BACKGROUND: Studies have reported development of pulmonary hypertension (PH) secondary to reduced LA compliance following AF ablation. OBJECTIVES: We aimed to compare the risk of worsening of baseline PH between non-paroxysmal AF patients undergoing pulsed-field ablation (PFA) and standard radiofrequency ablation (RFA). METHODS: This multicenter study included 28 nonparoxysmal AF patients with PH undergoing a PFA-based ablation procedure after >1 failed RFA. A cohort of 28 AF patients with PH, scheduled for repeat RFA, 1:1 propensity-score matched using a multivariable logistic model, were used as the comparator group. Right heart catheterization and echocardiography were performed before and after the procedure to assess the pulmonary artery pressure (PAP). PH was defined as resting mean PAP of >20 mm Hg. RESULTS: The baseline characteristics of the PFA and propensity-matched RFA groups were comparable. The mean PAP assessments at baseline, follow-up, and change from baseline were analyzed. The groups had comparable baseline mean pulmonary artery pressures (mPAP) (P = 0.177). After adjustment for baseline mPAP in an analysis of covariance model, the least-squares means change at 3 months after ablation was -1.71 ± 1.03 mm Hg and 19.67 ± 1.03 mm Hg in PFA and RFA, respectively (P <0.001). CONCLUSIONS: In this propensity-matched population, no worsening of mPAP was detected following pulsed-field ablation in patients with pre-existing PH undergoing a repeat procedure for recurrence.

Catheter ablation approach and outcome in HIV+ patients with recurrent atrial fibrillation.

INTRODUCTION: Earlier studies have shown a clear association between severity of human immunodeficiency virus (HIV) infection and incident atrial fibrillation (AF). We present the long-term outcome of catheter ablation (CA) and electrophysiological characteristics in HIV+ AF patients. METHODS: This study evaluated 1438 consecutive AF patients [31 (2.15%) with HIV and 1407 (97.8%) without HIV diagnosis] undergoing their first CA at our center. A total of 31 HIV patients and 31 controls were generated by propensity matching, based on calculated risk factor scores, using a logistic model. During first procedure, all received isolation of pulmonary vein (PV) + posterior wall and superior vena cava. Non-PV triggers, defined as ectopic triggers originating from sites other than PVs, were identified at the redo ablation with high-dose isoproterenol challenge. RESULTS: Clinical characteristics were not different between the groups. When compared to the control, by the end of 5 years after the first procedure, recurrence was significantly greater in HIV group [100% vs. 54%, p < .001]. Among patients that underwent redo ablation non-PV triggers were higher in HIV group [93.5% vs. 54%, p < .001], and most frequently originated from the coronary sinus [67.7% vs. 45.2%, p < .001] and left atrial appendage [41.9% vs. 25.8%, p < .001]. After focal ablation of non-PV trigger, no difference in arrhythmia recurrence between two groups [80.6% vs. 87.1%, p = .753] at 1-year follow up was found. CONCLUSION: Our findings suggest that non-PV triggers are highly prevalent in HIV+ AF patients resulting in higher rate of the mid- and long-term arrhythmia recurrence.

Impact of Colchicine Monotherapy on the Risk of Acute Pericarditis Following Atrial Fibrillation Ablation.

BACKGROUND: Acute pericarditis is a known complication of ablation procedures for atrial fibrillation (AF). OBJECTIVES: This study aimed to evaluate the benefits of colchicine monotherapy in terms of reducing the risk of pericarditis and related hospitalization rate in AF patients undergoing catheter ablation. METHODS: Consecutive AF patients undergoing first catheter ablation were classified into 3 groups based on their colchicine use: Group 1: no colchicine; group 2: colchicine from 7 days before to 1 month after ablation; and group 3: colchicine from the day of the procedure to 1 month after. Standard institutional protocol was used to follow all patients for 1 year. RESULTS: A total of 1,075 patients were classified into groups 1 (n = 607), 2 (n = 213), and 3 (n = 255). Symptoms of acute pericarditis were reported in 129 patients (12%): group 1: n = 106 (17.5%); group 2: n = 4 (1.9%); and group 3: n = 19 (7.5%); P < 0.001. Rate of mild-moderate as well as severe pericarditis were significantly lower in group 2. In the multivariable regression analysis, pre- and post-ablation colchicine use was seen to be associated with significantly lower risk of acute pericarditis and related hospitalization compared with the other 2 groups. In addition, at 1-year follow-up, arrhythmia-free survival rate was significantly higher in paroxysmal AF patients receiving colchicine compared with the no-colchicine population. CONCLUSIONS: Colchicine therapy starting 7 days before to 1 month after the ablation procedure was associated with significantly lower risk of acute pericarditis and related hospitalization. In addition, paroxysmal AF patients receiving colchicine had a higher arrhythmia-free survival rate compared with those not receiving colchicine.

Best ablation strategy in patients with premature ventricular contractions with multiple morphology: a single-centre experience.

AIMS: This study aimed to examine the clinical benefits of targeted ablation of all Premature ventricular complex (PVC) morphologies vs. predominant PVC only. METHODS AND RESULTS: A total of 171 consecutive patients with reduced left ventricular ejection fraction (LVEF) and ≥2 PVC morphology with high burden (>10%/day) undergoing their first ablation procedure were included in the analysis. At the initial procedure, prevalent PVC alone was ablated in the majority. However, at the redo, all PVC morphologies were targeted for ablation. : At the first procedure, 152 (89%) patients received ablation of the dominant PVC only. In the remaining 19 (11%) patients, all PVC morphologies were ablated. At two years, high PVC burden was detected in 89 (52%) patients. Repeat procedure was performed in 78 of 89, where all PVC morphologies were ablated. At 5 years after the repeat procedure, 71 (91%) had PVC burden of <5% [3.8 ± 1.1% vs. 15.4 ± 4.3% in successful vs. failed subjects (P < 0.001)]. In patients with low PVC burden after the initial procedure, LVEF improved from 37.5% to 41.6% [mean difference (MD): 3.39 ± 2.9%, P < 0.001], whereas a reduction in LVEF from 39.8% to 34.5% (MD: 6.45 ± 4.7%, P < 0.001) was recorded in patients with high PVC burden. One year after the repeat procedure, LVEF improved from 36.2% to 41.7% (MD: 5.5 ± 4.3%, P < 0.001) in patients with successful ablation. CONCLUSION: In this observational series, ablation of all PVC morphologies was associated with significantly lower PVC burden and improvement of LVEF at long-term follow-up, compared with ablation of the dominant morphology only.

Prevalence of atrial fibrillation and procedural outcome in patients undergoing catheter ablation for premature ventricular complexes.

INTRODUCTION: Atrial fibrillation (AF) and premature ventricular complexes (PVC) are common arrhythmias. We aimed to investigate AF prevalence in patients with PVC and its impact on PVC ablation outcomes. METHODS: Consecutive patients undergoing PVC ablation at a single institution between 2016 and 2019 were included and prospectively followed for 2 years. Patients with severe valvular heart disease, hyperthyroidism, malignancy, alcohol use disorder and advanced renal/hepatic diseases were excluded. Twelve-lead electrocardiograms were used to diagnose AF and assess PVC morphology. All PVCs were targeted for ablation using 4-mm irrigated-tip catheters at standardized radiofrequency power guided by 3-D mapping and intracardiac echocardiography. Patients were followed with remote monitoring, device interrogations and office visits every 6 months for 2 years. Detection of any PVCs in follow-up was considered as recurrence. RESULTS: A total of 394 patients underwent PVC ablation and 96 (24%) had concurrent AF. Patients with PVC and AF were significantly older (68.2 ± 10.8 vs. 58.3 ± 15.8 years, p < .001), had lower LV ejection fraction (43.3 ± 13.3% vs. 49.6 ± 12.4%, p < .001), higher CHA2 DS2 -VASc (2.8 ± 1.3 vs. 2.0 ± 1.3, p < .001) than those without. PVCs with ≥2 morphologies were detected in 60.4% and 13.7% patients with vs without AF (p < .001). At 2-year follow-up, PVC recurrence rate was significantly higher in patients with vs without AF (17.7% vs. 9.4%, p = .02). CONCLUSION: AF was documented in 1/4 of patients undergoing PVC ablation and was associated with lower procedural success at long-term follow-up. This was likely attributed to older age, worse LV function and higher prevalence of multiple PVC morphologies in patients with concurrent AF.

Catheter Ablation for Atrial Fibrillation in Adult Congenital Heart Disease: An International Multicenter Registry Study.

BACKGROUND: Data on atrial fibrillation (AF) ablation and outcomes are limited in patients with congenital heart disease (CHD). We aimed to investigate the characteristics of patients with CHD presenting for AF ablation and their outcomes. METHODS: A multicenter, retrospective analysis was performed of patients with CHD undergoing AF ablation between 2004 and 2020 at 13 participating centers. The severity of CHD was classified using 2014 Pediatric and Congenital Electrophysiology Society/Heart Rhythm Society guidelines. Clinical data were collected. One-year complete procedural success was defined as freedom from atrial tachycardia or AF in the absence of antiarrhythmic drugs or including previously failed antiarrhythmic drugs (partial success). RESULTS: Of 240 patients, 127 (53.4%) had persistent AF, 62.5% were male, and mean age was 55.2±13.3 years. CHD complexity categories included 147 (61.3%) simple, 68 (28.3%) intermediate, and 25 (10.4%) severe. The most common CHD type was atrial septal defect (n=78). More complex CHD conditions included transposition of the great arteries (n=14), anomalous pulmonary veins (n=13), tetralogy of Fallot (n=8), cor triatriatum (n=7), single ventricle physiology (n=2), among others. The majority (71.3%) of patients had trialed at least one antiarrhythmic drug. Forty-six patients (22.1%) had reduced systemic ventricular ejection fraction <50%, and mean left atrial diameter was 44.1±8.2 mm. Pulmonary vein isolation was performed in 227 patients (94.6%); additional ablation included left atrial linear ablations (40%), complex fractionated atrial electrogram (19.2%), and cavotricuspid isthmus ablation (40.8%). One-year complete and partial success rates were 45.0% and 20.5%, respectively, with no significant difference in the rate of complete success between complexity groups. Overall, 38 patients (15.8%) required more than one ablation procedure. There were 3 (1.3%) major and 13 (5.4%) minor procedural complications. CONCLUSIONS: AF ablation in CHD was safe and resulted in AF control in a majority of patients, regardless of complexity. Future work should address the most appropriate ablation targets in this challenging population.

Impact of digital monitoring on compliance and outcome of lifestyle-change measures in patients with coexistent atrial fibrillation and obesity.

Introduction: Obesity, a known risk factor for atrial fibrillation (AF), is potentially reversible through lifestyle changes, including diet and physical activity. However, lack of compliance is a major obstacle in attaining sustained weight loss. We investigated the impact of patient engagement using a digital monitoring system on compliance for lifestyle-change measures and subsequent outcome. Methods: A total of 105 consecutive patients with coexistent AF and obesity (body mass index ≥28) were classified into 2 groups based on the monitoring method: group 1, use of digital platform (n = 20); group 2, conventional method (n = 85). Group 1 used the RFMx digital monitoring platform (smartphone app) that sets weekly goals for exercise and weight loss, tracks patient compliance data continuously, and sends regular text reminders. Conventional method included monitoring patients' adherence to diet and change in weight during in-person clinic visits or monthly phone calls from staff. Results: Baseline characteristics of groups 1 and 2 were comparable. At 6 months of follow-up, 12 (60%) and 28 (33%) from group 1 and 2, respectively, were compliant with the physician instructions regarding diet and exercise (P = .025). Weight loss was observed in 9 of 12 (75%) from group 1 and 11 of 28 (39%) from group 2 (P = .038) and mean reduction in weight was 9.9 ± 8.9 lb and 4.0 ± 2.1 lb (P = .042). Conclusion: In this series, continuous digital monitoring was seen to be associated with significant improvement in compliance through better patient engagement, resulting in more weight loss compared to the conventional method.

Endocardial Scar-Homogenization With vs Without Epicardial Ablation in VT Patients With Ischemic Cardiomyopathy.

OBJECTIVES: In this study, the authors investigated the ablation success of scar homogenization with combined (epicardial + endocardial) vs endocardial-only approach for ventricular tachycardia (VT) in patients with ischemic cardiomyopathy (ICM) at 5 years of follow-up. BACKGROUND: Best ablation approach to achieve long-term success rate in VT patients with ICM is not known yet. METHODS: Consecutive ICM patients undergoing VT ablation at our center were classified into group 1: endocardial + epicardial scar homogenization and group 2: endocardial scar homogenization. Patients with previous open heart surgery were excluded. Epicardial ablation was performed despite being noninducible after endocardial ablation in all group 1 patients. All patients underwent bipolar substrate mapping with standard scar settings defined as normal tissue >1.5 mV and severe scar <0.5 mV. Noninducibility of monomorphic VT was the procedural endpoint in both groups. Patients were followed up every 4 months for 5 years with implantable device interrogations. RESULTS: A total of 361 patients (group 1: n = 70 and group 2: n = 291) were included in the study. At 5 years, 81.4% (n = 57/70) patients from group 1 and 66.3% (n = 193/291) from group 2 were arrhythmia-free (P = 0.01) Of those patients, 26 of 57 (45.6%) and 172 of 193 (89.1%) from group 1 and group 2 respectively were on anti-arrhythmic drugs (AAD) (log-rank P < 0.001). After adjusting for age, sex, and obstructive sleep apnea, endo-epicardial scar homogenization was associated with a significant reduction in arrhythmia-recurrence (HR: 0.48; 95% CI: 0.27-0.86; P = 0.02). CONCLUSIONS: In this series of patients with ICM and VT, epicardial substrate was detected in all group 1 patients despite being noninducible after endocardial ablation. Moreover, combined endo-epicardial scar homogenization was associated with a significantly higher success rate at 5 years of follow-up and a substantially lower need for antiarrhythmic drugs after the procedure compared with the endocardial ablation alone.

Recovery of Conduction Following High-Power Short-Duration Ablation in Patients With Atrial Fibrillation: A Single-Center Experience.

[Figure: see text].

Impact of Oral Anticoagulation Therapy Versus Left Atrial Appendage Occlusion on Cognitive Function and Quality of Life in Patients With Atrial Fibrillation.

Background We compared the cognitive status and quality of life in patients with atrial fibrillation undergoing left atrial appendage occlusion (LAAO) or remaining on oral anticoagulation (OAC) after atrial fibrillation ablation. Methods and Results Cognition was assessed by the Montreal Cognitive Assessment (MoCA) survey at baseline and follow-up. Consecutive patients receiving LAAO or OAC after atrial fibrillation ablation were screened, and patients with a score of ≤17 were excluded from the study. Quality of life was measured at baseline and 1 year using the Atrial Fibrillation Effect on Quality of Life survey. A total of 50 patients (CHA2DS2-VASc [congestive heart failure, hypertension, age≥75 years, diabetes mellitus, stroke or transient ischemic attack, vascular disease, age 65-74 years, sex category] score: 3.30±1.43) in the LAAO group and 48 (CHA2DS2-VASc score 2.73±1.25) in the OAC group were included in this prospective study. Mean baseline MoCA score was 26.18 and 26.08 in the LAAO and OAC groups, respectively (P=0.846). At 1 year, scores were 26.94 and 23.38 in the respective groups. MoCA score decreased by an estimated -2.74 (95% CI, -3.61 to -1.87; P<0.0001) points in the OAC group, whereas the change in the LAAO group was nonsignificant (0.79; (95% CI, -0.06 to 1.64; P=0.07). After adjusting for baseline clinical characteristics, remaining on OAC was an independent predictor of MoCA change at 1 year (regression coefficient, -3.38; 95% CI, -4.75 to -2.02; P<0.0001). Change in Atrial Fibrillation Effect on Quality of Life score did not differ significantly in achieving a clinically important difference between groups. Conclusions In this series, a significant difference in the postprocedure MoCA score was observed in postablation patients with atrial fibrillation receiving LAAO versus remaining on OAC with a substantial decline in the score in the OAC group. However, quality of life improved similarly across groups. Registration https://www.ClinicalTrials.gov. Unique identifier: NCT01816308.

Thromboembolic Risk in Atrial Fibrillation Patients With Left Atrial Scar Post-Extensive Ablation: A Single-Center Experience.

OBJECTIVES: This study evaluated the association of the post-ablation scar with stroke risk in patients undergoing atrial fibrillation (AF) ablation. BACKGROUND: Late gadolinium enhancement-cardiac magnetic resonance studies have reported a direct association between pre-ablation left atrial scar and thromboembolic events in patients with AF. METHODS: Consecutive patients with AF were classified into 2 groups based on the type of ablation performed at the first procedure. Group 1 involved limited ablation (isolation of pulmonary veins, left atrial posterior wall, and superior vena cava); and group 2 involved extensive ablation (limited ablation + ablation of nonpulmonary vein triggers from all sites except left atrial appendage). During the repeat procedure, post-ablation scar (region with bipolar voltage amplitude <0.5 mV) was identified by using 3-dimensional voltage mapping. RESULTS: A total of 6,297 patients were included: group 1, n = 1,713; group 2, n = 4,584. Group 2 patients were significantly older and had more nonparoxysmal AF. Nineteen (0.3%) thromboembolic events were reported after the first ablation procedure: 9 (1.02%) in group 1 and 10 (0.61%) in group 2 (p = 0.26). At the time of the event, all 19 patients were experiencing arrhythmia. Median time to stroke was 14 (interquartile range: 9 to 20) months in group 1 and 14.5 (interquartile range: 8 to 18) months in group 2. Post-ablation scar data were derived from 2,414 patients undergoing repeat ablation. Mean scar area was detected as 67.1 ± 4.6% in group 2 and 34.9 ± 8.8% in group 1 at the redo procedure (p < 0.001). CONCLUSIONS: Differently from the cardiac magnetic resonance-detected pre-ablation scar, scar resulting from extensive ablation was not associated with increased risk of stroke compared with that from the limited ablation.

Creating a safe workplace by universal testing of SARS-CoV-2 infection in asymptomatic patients and healthcare workers in the electrophysiology units: a multi-center experience.

BACKGROUND: As the coronavirus cases continue to surge, the urgent need for universal testing to identify positive cases for effective containment of this highly contagious pandemic has become the center of attention worldwide. However, in spite of extensive discussions, very few places have even attempted to implement it. We evaluated the efficacy of widespread testing in creating a safe workplace in our electrophysiology (EP) community. Furthermore, we assessed the new infection rate in patients undergoing EP procedure, to see if identification and exclusion of positive cases facilitated establishment of a risk-free operating environment. METHODS: Viral-RNA and serology tests were conducted in 1670 asymptomatic subjects including patients and their caregivers and staff in our EP units along with the Emergency Medical Service (EMS) staff. RESULTS: Of 1670, 758 (45.4%) were patients and the remaining 912 were caregivers, EMS staff, and staff from EP clinic and lab. Viral-RNA test revealed 64 (3.8%) positives in the population. A significant increase in positivity rate was observed from April to June 2020 (p = 0.02). Procedures of positive cases (n = 31) were postponed until they tested negative at retesting. Staff testing positive (n = 33) were retested before going back to work after 2 weeks. Because of suspected exposure, 67 staff were retested and source was traced. No new infections were reported in patients during or within 2 weeks after the hospital-stay. CONCLUSIONS: Universal testing to identify positive cases was helpful in creating and maintaining a safe working environment without exposing patients and staff to new infections in the EP units. TRIAL REGISTRATION: Trial Registration Number: clinicaltrials.gov : NCT04352764.