Need For Electrical Cardioversion Research Articles

Acute clinical outcomes of patients with HFpEF undergoing atrial fibrillation ablation

Abstract Aim Robust data show that atrial fibrillation (AF) ablation can improve left ventricular function and prevent cardiovascular complications in patients with heart failure and reduced ejection fraction. The effectiveness and safety of AF ablation in patients with heart failure and preserved ejection fraction (HFpEF) is less well characterized. Methods We retrospectively analyzed 785 consecutive patients with normal left ventricular function undergoing AF ablation in a high-volume center including 251 with AF and HFpEF. We compared baseline parameters, procedural details and procedural complications by heart failure status. Results Patients with HFpEF (n=251/785) were older (median age 70 years vs. 64 years; p < 0.05) and more frequently female (48.2% vs. 32.2%; p < 0.05) compared to patients without HF. Symptom severity was comparable with a median European Heart Rhythm Association score of 2 in both groups (p > 0.05). Arterial (71.7% vs. 59.7%, p < 0.05), diabetes (16.7% vs. 9.4%, p < 0.05) and dyslipidemia (41.4% vs. 27.2%, p < 0.05) were more common in patients with AF and HFpEF. Acute pulmonary vein isolation (PVI) was achieved in all patients using cryoballoon or radiofrequency energy with similar frequency in both groups (cryoballoon ablation: 37.8% vs. 41.6%; p > 0.05). A subgroup of patients in both groups additionally underwent cavotricuspid isthmus ablation for coexistent atrial flutter (26% vs. 20.7%; p > 0.05). Procedure times (119.4 ± 47.7 min vs. 120.2 ± 48.3 min; p > 0.05) and fluoroscopy times (15.8 ± 10.4 min vs. 15.5 ± 7.1 min; p > 0.05) were comparable. Overall complication rates did not differ (12.7% vs. 10.3%; p > 0.05). While the incidence of pericardial tamponades was slightly higher (2% vs. 0%), other severe and minor complications showed no significant differences, including stroke/transient ischemic attack (TIA; 0.4% vs. 0.6%), major life-threatening bleeding (0% vs. 0.2%), vascular complications (1.6% vs. 2.1%), phrenic nerve palsy (0.8% vs. 1.5%), and pulmonary vein stenosis (0.4 vs. 0%). The mean in-hospital stay for the procedure was 2 days in both groups (p > 0.05). In-hospital recurrence rates were similar (12.4% vs. 17%; p > 0.05), as was the need for electrical cardioversion before discharge (5.6% vs. 6.6%; p > 0.05). Conclusion Patients with HFpEF undergoing AF ablation were older, more frequently female, and have more comorbidities than patients without heart failure. Acute procedural success and acute complication rates appear low. These data encourage randomized evaluations of the safety and efficacy of ablation-based rhythm control therapy in patients with AF and HFpEF.

Cryoballoon ablation for atrial fibrillation in octogenarians: a propensity score-based analysis with a younger cohort.

In terms of safety and efficacy, cryoballoon ablation (CB-A) has become a valid option for achieving pulmonary vein isolation (PVI) in patients affected by symptomatic atrial fibrillation. However, CB-A data in octogenarians are still scarce and limited to single-centre experiences. The present multicentre study aimed to compare the outcomes and complications of index CB-A in patients older than 80 years with a cohort of younger patients. We retrospectively enrolled 97 consecutive patients aged ≥80 years who underwent PVI using the second-generation CB-A. This group was compared with a younger cohort of patients using a 1:1 propensity score matching. After the matching, 70 patients from the elderly group were analysed and compared with 70 younger patients (control group). The mean age was 81.4 ± 1.9 years among octogenarians and 65.2 ± 10.2 years in the younger cohort. The global success rate after a median follow-up of 23 [18-32.5] months was 60.0% in the elderly group and 71.4% in the control group (P = 0.17). Phrenic nerve palsy was the most common complication occurring in a total of 11 patients (7.9%): in 6 (8.6%) patients in the elderly group and in 5 patients (7.1%) in the younger group (P = 0.51). Only two (1.4%) major complications occurred: one (1.4%) femoral artery pseudoaneurysm in the control group, which resolved with a tight groin bandage, and one (1.4%) case of urosepsis in the elderly group. Arrhythmia recurrence during the blanking period and the need for electrical cardioversion to restore sinus rhythm after PVI were found to be the only independent predictors of late arrhythmia relapses. The present study showed that CB-A PVI is as feasible, safe and effective among appropriately selected octogenarians as it is in younger patients.

P385 CRYOBALLOON ABLATION FOR ATRIAL FIBRILLATION IN OCTOGENARIANS: A PROPENSITY–SCORE MATCHING COMPARISON WITH A COHORT OF YOUNGER PATIENTS

Abstract Background Atrial fibrillation (AF) is the most frequent sustained cardiac arrhythmia in adults with a current estimated prevalence between 2–4% in the general population. AF prevalence increases with advancing age and it is estimated that nearly 10% of octogenarians may be affected by this arrhythmia. In terms of safety and efficacy, Cryoballoon ablation (CB–A) has become a valid option for achieving pulmonary vein isolation (PVI) in patients affected by symptomatic atrial fibrillation (AF). However, CB–A data in octogenarians are still scarce and limited to single–centre experiences. The present multicenter study aimed to compare the outcomes and complications of index CB–A in patients older than 80 years old with a cohort of younger patients. Methods and results We retrospectively enrolled 97 consecutive patients aged ≥ 80 years who underwent PVI using the second–generation CB–A. This group was compared with a younger cohort of patients using a 1:1 Propensity score matching. After the matching, 70 patients from the elderly group were analyzed and compared with 70 younger patients (control group). The mean age was 81.4 ± 1.9 years among octogenarians and 65.2 ± 10.2 years in the younger cohort. The global success rate after a median follow–up of 23 [18 – 32.5] months was 60.0% in the elderly group and 71.4% in the control group (p = 0.17). Phrenic nerve palsy (PNP) was the most common complication occurring in a total of 11 patients (7.9%): in 6 (8.6%) patients for the elderly group and in 5 patients (7.1%) of the younger group (p = 0.51). Only 2 (1.4 %) major complications occurred: 1 (1.4%) femoral artery pseudoaneurysm in the control group, which resolved with a tight groin bandage and 1 (1.4%) case of urosepsis in the elderly group. Arrhythmia recurrence during the blanking period (BP) and the need for electrical cardioversion (ECV) to restore sinus rhythm after PVI were found to be the only independent predictors of late arrhythmia relapses. Conclusions The present study showed that CB–A PVI is as feasible, safe and effective among octogenarians as it is in younger patients.

670 DEXMEDETOMIDINE SEDATION FOR PULMONARY VEIN ISOLATION PROCEDURE

Abstract Background Peri-procedural anesthesia for catheter ablation of atrial fibrillation (AF) varies from conscious sedation to general anesthesia. Current guidelines do not suggest any specific strategy, thus the choice between different protocols is mainly driven by local expertise, operator and/or patient preference and availability of a dedicated anesthesiology team. Propofol is often the drug of choice despite the risk of respiratory depression. Few data have recently reported operator-directed nurse-administered dexmedetomidine (DEX) sedation as an effective and safe strategy. Aim of the study To evaluate the outcomes of operator-directed nurse-administered DEX sedation in AF ablation (pulmonary vein isolation-PVI). Method Between May 2022 and August 2022, 41 consecutive patients (male 83%, median age 64 years, IQR 57-71) with drug-refractory paroxysmal (n.27;66%) or persistent AF (n.14;34%) underwent first PVI procedure under DEX sedation. Our sedation protocol consisted of continuous intravenous administration of DEX (0.2–0,7 µg/kg/hr) titrated throughout the procedure to achieve mild to moderate sedation (Modified Observer's Assessment of Alertness and Sedation Scale 2-3). A single dose of Ondansetron (4 mg) was administered in the beginning of procedure. Adjunctive doses of fentanyl (cumulative dose 50-100 µg) were administered before the beginning of radiofrequency (RF) delivery and in case of inadequate control of the pain. A low dose propofol bolus (<1mg/kg) was eventually added for electrical cardioversion (ECV). Sedation-related complications were evaluated, including sustained hypoxemia (SpO2 <90%), need of anesthesiologist support and persistent hypotension (SBP < 90 mmHg). The day after the procedure, patients’ satisfaction and pain (0-100 scale) were assessed by a standardized questionnaire. Results Pulmonary vein isolation was performed either with Low Power Long Duration (LPLD, n.17;41,46%) or High-Power Short Duration (HPSD, n.24;58,54%) RF protocol. Median procedure time was 135’ (IQR 110-170’). Median DEX dose was 0,30 µg/kg/hr (IQR 0,27-0,33 µg/kg/hr). Median fentanyl dose was 75 µg (IQR 50-100 µg). In patients needing for ECV (n. 16; 39%), median propofol dose was 60 mg (IQR 47,5–105 mg). Thirteen patients (31,7%) had one or more significant risk factor (obesity, severe heart failure, pulmonary comorbidity, coronary artery disease) for anesthesia-related complications. Median pain scale value was 20 (IQR 10-50). Majority of patients (90,2%, n.37) reported mild to moderate pain (pain <60/100) during the procedure and satisfaction was overall high (median value 90, IQR 80-100), with a 90,2% of patients declaring a satisfaction of 60/100 or more. These results were independent from baseline characteristics (sex, age, AF type, HF, CAD, pulmonary comorbidity, obesity) and procedural aspects (LPLD vs HPSD, procedure time, need for ECV). A strong linear correlation was found between patients’ satisfaction and reported pain (r=-0,59). Only 1 (2,4%) sedation-related complication occurred, consisting in sustained post procedural hypotension treated with volume repletion. Conclusions in our experience, dexmedetomidine (DEX) sedation protocol during catheter ablation of atrial fibrillation is associated to high patients’ satisfaction and no respiratory complications. It seems to be also feasible in patients at higher risk for anesthesia-related complications (severe heart failure, BMI > 30 kg/m2), generally excluded from previous studies.

Characteristics of Postoperative Atrial Fibrillation and the Effect of Posterior Pericardiotomy

BackgroundPostoperative atrial fibrillation (POAF) is a frequent complication of cardiac surgery. However, only a few detailed descriptions of the arrhythmia have been reported. We aim to describe the characteristics, outcomes, and variables associated with POAF and to evaluate how posterior pericardiotomy (PP) affects POAF characteristics. MethodsIn this post hoc analysis of the Posterior left pericardiotomy for the prevention of AtriaL fibrillation After Cardiac Surgery (PALACS) trial, we describe POAF characteristics based on continuous in-hospital telemetry data. ResultsOf 420 patients, 103 (24.5%) developed POAF. Median time to onset was 50.3 hours; 70.9% of events occurred within 3 days. Hemodynamic instability and rapid ventricular response occurred in 8.7% and 51.5% of cases, respectively. Most POAF patients received antiarrhythmics (97.1%), 22.3% electrical cardioversion, and 40.8% systemic anticoagulation. Median POAF duration was 24.0 hours; 70.9% of cases resolved within 36 hours. Median POAF burden was 15.9%. All patients were in sinus rhythm at follow-up. POAF was associated with longer hospitalization (7 vs 6 days; P < .001), but not increased mortality or morbidity. PP reduced POAF incidence (17.7% vs 31.3%; P = .001), especially after postoperative day 2 (time to POAF onset 41.9 vs 57.1 hours; P = .01). Age was associated with POAF. Female sex, coronary artery bypass grafting, beta blockers, and PP were inversely associated. ConclusionsPOAF remains frequent after cardiac surgery. Hemodynamic instability is rare, although rapid ventricular response and need for electrical cardioversion are frequent. POAF burden is significant, and the arrhythmias resolve within 30 days. PP reduces POAF especially after postoperative day 2.

Alleviation of AF related symptoms following acute conversion of recent-onset, symptomatic atrial fibrillation to sinus rhythm with flecainide acetate oral inhalation solution

Abstract Introduction Pharmacological restoration of sinus rhythm (SR) in patients with symptomatic atrial fibrillation (AF) is expected to be accompanied by prompt alleviation of symptoms to avoid the need for electrical cardioversion (ECV) and/or hospitalization. The feasibility and safety of acute cardioversion of recent-onset (≤48 hours) symptomatic AF to SR with flecainide acetate oral inhalation (FlecIH) solution was shown in the Phase 2, open-label INSTANT trial. We examined symptoms, heart rate, time to discharge and need for ECV reported among patients in the INSTANT trial whose AF was successfully converted to SR (“conversion group”; N=25) versus those whose AF did not convert to SR (“no conversion group”; N=29). Methods Conversion success was determined using 12-lead Holter monitoring during a 90-minute observation period. Patients in the no conversion group were offered alternative treatment per the investigator discretion. Symptoms, vital signs, time to discharge, and the need for ECV were evaluated through Day 5. Results Data from 54 patients (33.3% female) with a mean age of 62.1 years and a mean BMI of 26.8 kg/m2 were analyzed. All patients reported at least one AF-related symptoms at baseline (palpitations=85%; dizziness=35%; shortness of breath=37%; chest discomfort=39%) and 83.3% presented with AF symptoms ≤24 hours in duration. At 90 minutes, 80.0% of the conversion group were asymptomatic compared to 37.9% of the no conversion group (p&amp;lt;0.001). Mean (SD) ventricular rate at 90 minutes was 70.6 (12.5) bpm in the conversion group compared to 100.4 (29.4) bpm in the no conversion group (p&amp;lt;0.001). Median time to discharge was 2.3 (IQR: 0.75) hours for the conversion group compared to 3.6 (IQR: 1.02) hours for the no conversion group (p=0.001). By Day 5, 23 (79.3%) patients in the no conversion group had undergone ECV; no patients in the conversion group experienced AF recurrence by Day 5 (0% required ECV; p&amp;lt;0.001). Conclusions Conversion of recent onset AF to SR with inhaled flecainide was associated with a reduction in symptoms, normalization of heart rate, rapid hospital discharge and avoidance of ECV during a 5-day follow-up period. Funding Acknowledgement Type of funding sources: Private company. Main funding source(s): InCarda Therapeutics

Higher Incidence of Stroke in Severe COVID-19 Is Not Associated With a Higher Burden of Arrhythmias: Comparison With Other Types of Severe Pneumonia.

Aims: Thromboembolic events, including stroke, are typical complications of COVID-19. Whether arrhythmias, frequently described in severe COVID-19, are disease-specific and thus promote strokes is unclear. We investigated the occurrence of arrhythmias and stroke during rhythm monitoring in critically ill patients with COVID-19, compared with severe pneumonia of other origins.Methods and Results: This retrospective study included 120 critically ill patients requiring mechanical ventilation in three European tertiary hospitals, including n =60 COVID-19, matched according to risk factors for the occurrence of arrhythmias in n = 60 patients from a retrospective consecutive cohort of severe pneumonia of other origins. Arrhythmias, mainly atrial fibrillation (AF), were frequent in COVID-19. However, when compared with non-COVID-19, no difference was observed with respect to ventricular tachycardias (VT) and relevant bradyarrhythmias (VT 10.0 vs. 8.4 %, p = ns and asystole 5.0 vs. 3.3%, p = ns) with consequent similar rates of cardiopulmonary resuscitation (6.7 vs. 10.0%, p = ns). AF was even more common in non-COVID-19 (AF 18.3 vs. 43.3%, p = 0.003; newly onset AF 10.0 vs. 30.0%, p = 0.006), which resulted in a higher need for electrical cardioversion (6.7 vs. 20.0%, p = 0.029). Despite these findings and comparable rates of therapeutic anticoagulation (TAC), the incidence of stroke was higher in COVID-19 (6.7.% vs. 0.0, p = 0.042). These events also happened in the absence of AF (50%) and with TAC (50%).Conclusions: Arrhythmias were common in severe COVID-19, consisting mainly of AF, yet less frequent than in matched pneumonia of other origins. A contrasting higher incidence of stroke independent of arrhythmias also observed with TAC, seems to be an arrhythmia-unrelated disease-specific feature of COVID-19.

Higher incidence of stroke in severe COVID-19 is not associated with a higher burden of arrhythmias: comparison to other types of severe pneumonia

BackgroundThromboembolic events, including stroke, are typical complications of COVID-19. Whether arrhythmias, frequently described in severe COVID-19, are disease-specific and thus promote strokes is unclear. We investigated the occurrence of arrhythmias, and stroke during rhythm monitoring in critically ill COVID-19, compared to severe pneumonias of other origin.MethodsRecruited were 120 critically ill patients requiring mechanical ventilation in three European tertiary hospitals, including n=60 COVID-19, matched according to risk factors for occurrence of arrhythmias to n=60 patients from a retrospective consecutive cohort of severe pneumonias of other origin.ResultsArrhythmias, mainly atrial fibrillation (AF), were frequent in COVID-19. However, when compared to nonCOVID-19, no difference was observed with respect to ventricular tachycardias (VT) and relevant bradyarrhythmias (VT 10.0 vs. 8.4%, p=ns and asystole 5.0 vs. 3.3%, p=ns) with consequent similar rates of cardiopulmonary resuscitation (6.7 vs. 10.0% p=ns). AF was even more common in nonCOVID-19 (AF 18.3 vs. 43.3%, p=0.003; newly onset AF 10.0 vs. 30.0%, p=0.006) which resulted in higher need for electrical cardioversion (6.7 vs. 20.0%, p=0.029). Despite these findings and comparable rates of therapeutic anticoagulation (TAC), the incidence of stroke was higher in COVID-19 (6.7.% vs. 0.0, p=0.042). These events happened also in absence of AF (50%) and with TAC (50%).ConclusionArrhythmias were common in severe COVID-19, consisting mainly of AF, yet less frequent than in matched pneumonias of other origin. A contrasting higher incidence of stroke independent of arrhythmias observed also with TAC, seems to be an arrhythmia-unrelated disease-specific feature of COVID-19.Funding AcknowledgementType of funding sources: None. Figure 1

Reversal of unstable atrial fibrillation after surgical correction of hiatus hernia: A case report.

IntroductionThe presence of Atrial Fibrillation (AF) with herniation of abdominal content through the esophageal hiatus can be explained by the compression of the cardiac tissue by the viscera and, consequently, of its electrical transmission network, compromising the correct propagation of stimuli.Due to the causal relationship, hernia correction is almost always able to reverse the arrhythmic picture.Presentation of the caseA 75-year-old male with atrial fibrillation with a large hiatal hernia causing clinical decompensation was successfully treated after a laparocopic correction- primary closure of the defect was made with barbed surgical thread plus and placing a biological mesh (porcine small intestine submucosa, non-cross-linked), fixed with cyanoacrylate; after the procedure, he was discharged asymptomatic and with sinus heart rhythm.DiscussionIt is noticed that for cases in which the patient presents with a type IV hiatal hernia associated with atrial fibrillation, the laparoscopic correction of hernia using a mesh for the correction of the defect has good results in the literature.In the present case, it is noted that despite the severity of the condition denoted by hemodynamic instability and the need for electrical cardioversion, the surgical correction of the hiatal hernia was able to reverse the arrhythmic picture definitively.Conclusionthe concomitance of AF and hiatal hernia can explain the difficulty to control the arrhythmic picture and is necessary to consider, as soon as possible, the surgical correction of the defect as part of the treatment.

Electrical cardioversion during cryoballoon pulmonary vein isolation predicts long-term ablation success in persistent atrial fibrillation

Abstract Funding Acknowledgements Type of funding sources: None. Background Cryoballoon pulmonary vein isolation (cryoPVI) is an established option for treatment of atrial fibrillation (AF) but many periprocedural events influencing long-term outcome and procedural safety of ablation remain unclear. In radiofrequency ablation studies, failure to convert to sinus rhythm and electrical cardioversion (ECV) have been associated with increased recurrence rates. In this context, the influence of ECV during cryoPVI on long-term ablation efficacy is unclear. Objective A prospective comparison of AF recurrence after cryoballoon ablation in patients who were in AF or atrial tachycardia at the beginning of cryoPVI requiring ECV during procedure with patients who underwent ablation therapy without ECV. Methods We analyzed consecutive patients who underwent cryoPVI in a single-center cohort between 2018 and 2020. Follow-up was performed at 3, 6, 12, 18 and 24 months after ablation. Primary endpoints were: symptomatic AF recurrence for efficacy and bleeding, phrenic nerve injury, stroke or death for safety. Results 472 consecutive patients who underwent ablation in a single-center cohort were analysed. Mean follow-up time was 15 months. In 195 patients (74 paroxysmal AF vs. 121 persistent AF, age 69 ± 10 years, 57% male, CHA2DS2-VASc 2.6 ± 1.4) at least one ECV was performed following ablation, while no cardioversion was necessary in 277 patients (214 paroxysmal AF vs. 63 persistent AF, age 69 ± 10 years, 55% male, CHA2DS2-VASc 2.7 ± 1.5). After 24 months, primary efficacy endpoint occurrence was significantly higher in persistent AF requiring cardioversion during procedure than for persistent AF without cardioversion and paroxysmal AF with/ without cardioversion (56.1 % vs. 31.2%, 33.6%, 32.9%, log-rank p = 0.009, figure). Primary safety endpoint occurred in form of pericardial effusion or transient phrenic nerve injury in two patients in cardioversion group (1.0%) and three patients without cardioversion (1.1%). No deaths or strokes were observed in either group. Total procedure duration (55.6 ± 17min vs. 57.7 ± 15.9min, P = 0.17) and left-atrial dwell time (39.7 ± 14.9min vs. 42 ± 15.6min, P = 0.11) were similar. Conclusion In patients with persistent AF, the need for ECV during cryoPVI predicts a poorer long-term outcome during 2-year follow-up. Future studies should focus on this specific patient population. Abstract Figure.

Safety and Outcomes of Ventricular Tachycardia Substrate Ablation During Sinus Rhythm: A Prospective Multicenter Registry.

This study sought to analyze safety and outcomes of ventricular tachycardia (VT) substrate ablation during sinus rhythm (SR), without baseline VT induction. Safety and outcomes after scar-related VT ablation during SR are not well known. Hemodynamic instability and need for electrical cardioversion can compromise safety of VT ablation procedures. Four hundred twelve consecutive patients with structural heart disease undergoing VT ablation were included in a prospective multicenter registry. Substrate ablation during SR, without baseline VT induction, was the first step of the ablation procedure and the standard protocol. Scar dechanneling was the substrate ablation technique used. VT inducibility was tested after substrate ablation. VT induction protocol was negative after substrate ablation in 289 patients (70.1%), completing the procedure in SR. Procedure-related complication rate was 6.5%, including 1 death (0.2%). Thirty-day mortality after first VT ablation procedure was 1.7%. Overall survival was 95.8% and 88.6% at 1 and 3 years of follow-up, respectively. In a multivariable proportional hazards regression model, age≥70 years (hazard ratio [HR]: 4.95 [2.59 to 9.47]; p<0.001), chronic obstructive pulmonary disease (HR: 2.37 [1.24 to 4.52]; p=0.008), left ventricular ejection fraction<30% (HR: 2.43 [1.37 to 4.33]; p=0.002), and incomplete substrate ablation (HR: 2.37 [1.24 to 4.52]; p=0.026) were independent predictors of overall mortality. At 12months' follow-up, VT-free survival was 82.5% after 1 procedure and 87.8% after n procedures CONCLUSIONS: Substrate ablation during SR avoiding multiple VT induction has low procedure-related complications and low early mortality. Age, chronic obstructive pulmonary disease, and reduced left ventricular ejection fraction, but also incomplete substrate elimination, are predictors of mortality.

Handling of Ventricular Fibrillation in the Emergency Setting.

Ventricular fibrillation (VF) and sudden cardiac death (SCD) are predominantly caused by channelopathies and cardiomyopathies in youngsters and coronary heart disease in the elderly. Temporary factors, e.g., electrolyte imbalance, drug interactions, and substance abuses may play an additive role in arrhythmogenesis. Ectopic automaticity, triggered activity, and reentry mechanisms are known as important electrophysiological substrates for VF determining the antiarrhythmic therapies at the same time. Emergency need for electrical cardioversion is supported by the fact that every minute without defibrillation decreases survival rates by approximately 7%–10%. Thus, early defibrillation is an essential part of antiarrhythmic emergency management. Drug therapy has its relevance rather in the prevention of sudden cardiac death, where early recognition and treatment of the underlying disease has significant importance. Cardioprotective and antiarrhythmic effects of beta blockers in patients predisposed to sudden cardiac death were highlighted in numerous studies, hence nowadays these drugs are considered to be the cornerstones of the prevention and treatment of life-threatening ventricular arrhythmias. Nevertheless, other medical therapies have not been proven to be useful in the prevention of VF. Although amiodarone has shown positive results occasionally, this was not demonstrated to be consistent. Furthermore, the potential proarrhythmic effects of drugs may also limit their applicability. Based on these unfavorable observations we highlight the importance of arrhythmia prevention, where echocardiography, electrocardiography and laboratory testing play a significant role even in the emergency setting. In the following we provide a summary on the latest developments on cardiopulmonary resuscitation, and the evaluation and preventive treatment possibilities of patients with increased susceptibility to VF and SCD.

Likelihood of Spontaneous Cardioversion of Atrial Fibrillation Using a Conservative Management Strategy Among Patients Presenting to the Emergency Department

Numerous emergency department (ED) atrial fibrillation (AF) protocols have been developed to reduce hospitalizations, focusing on the use of cardioversion in the ED. An alternative strategy of rate control with early specialty follow-up may be more widely applicable. The likelihood of spontaneous cardioversion with such a protocol is unknown. Between 2015 and 2018, 157 patients who presented to the ED with a primary diagnosis of AF and were hemodynamically stable and with low to moderate symptom severity were discharged with early follow-up at an AF specialty clinic. Rhythm at short-term (within 72 hours), within 30-day follow-up, and need for electrical cardioversion was tabulated. Various demographic and co-morbidity variables were assessed to determine their association with likelihood of spontaneous cardioversion. At an average of 2.3 days, 63% and within 30 days, 83% had spontaneous cardioversion. By 90 days, only 6.3% required electrical cardioversion. Diabetes (38% vs 69%, p <0.01), coronary artery disease (39% vs 66%, p = 0.02), reduced ejection fraction (40% vs 72%, p <0.01), dilated right atrium (43% vs 73%, p <0.01) and moderate-to-severely dilated left atrium (38% vs 78%, p <0.01) predicted those who were less likely to convert to sinus rhythm. Most patients who present to the ED with AF will spontaneously convert to sinus rhythm by short-term (2 to 3 days) follow-up with a rate control strategy. In conclusion, aggressive use of electrical cardioversion in the ED may be unnecessary in hemodynamically stable patients without severe symptoms.

Intraoperative epicardial focal pulmonary venous electrocardiography in patients with atrial fibrillation.

In patients referred to off-pump coronary artery bypass grafting, pulmonary vein isolation (PVI) may be used for those with persistent atrial fibrillation (AF), an alternative to the Maze procedure. However, the success rate of PVI in persistent AF is limited. The study assesses the prognostic value of focal epicardial electrocardiography of the pulmonary veins (PVs) for surgical ablation results. We mapped 140 PV in 35 cases undergoing off-pump coronary artery bypass grafting. Data obtained using a sensing-pacing probe before ablation were analysed. The composite study end-point consisted of the need for electrical cardioversion for in-hospital recurrence of AF and the presence of AF at hospital discharge and after 6 months follow-up confirmed by 24-h Holter electrocardiographic monitoring. In patients with epicardial far-field (FF) signals recorded over at least 1 PV, the composite end-point occurred in 61% (14) vs 25% (3) of patients with no FF signal recorded over any PV (P = 0.04). The presence of FF signals in at least 1 PV significantly increased the risk of composite end-point occurrence (odds ratio 3; P = 0.04). The composite end-point occurred in 86% (6) of patients with FF signals recorded over all PVs and in 39% (11) in the remainder of the study population (P = 0.03). Intraoperative epicardial focal electrocardiography of PVs revealed more than 40% of PVs had only FF atrial signals. The presence of FF signals in PVs is related to a lower early effectiveness of PVI on ablating AF. Epicardial focal electrocardiography of PVs may be a clinically effective intraoperative tool in the decision-making process between less invasive PVI and the standard Maze procedure.

Predictors of sinus rhythm after electrical cardioversion of atrial fibrillation: results from a data mining project on the Flec-SL trial data set.

Data mining is the computational process to obtain information from a data set and transform it for further use. Herein, through data mining with supportive statistical analyses, we identified and consolidated variables of the Flecainide Short-Long (Flec-SL-AFNET 3) trial dataset that are associated with the primary outcome of the trial, recurrence of persistent atrial fibrillation (AF) or death. The 'Ranking Instances by Maximizing the Area under the ROC Curve' (RIMARC) algorithm was applied to build a classifier that can predict the primary outcome by using variables in the Flec-SL dataset. The primary outcome was time to persistent AF or death. The RIMARC algorithm calculated the predictive weights of each variable in the Flec-SL dataset for the primary outcome. Among the initial 21 parameters, 6 variables were identified by the RIMARC algorithm. In univariate Cox regression analysis of these variables, increased heart rate during AF and successful pharmacological conversion (PC) to sinus rhythm (SR) were found to be significant predictors. Multivariate Cox regression analysis revealed successful PC as the single relevant predictor of SR maintenance. The primary outcome risk was 3.14 times (95% CI:1.7-5.81) lower in those who had successful PC to SR than those who needed electrical cardioversion. Pharmacological conversion of persistent AF with flecainide without the need for electrical cardioversion is a powerful and independent predictor of maintenance of SR. A strategy of flecainide pretreatment for 48 h prior to planned electrical cardioversion may be a useful planning of a strategy of long-term rhythm control.

218-04: Substrate Ablation Before or After Ventricular Tachycardia Induction and Ablation. A Randomized Study

Background: Ventricular tachycardia (VT) induction and mapping as the first step in VT ablation procedures remains standard practice. However, the role and the optimal sequence of VT induction and ablation when combined with substrate ablation during procedures remains unclear. Methods and Results: Forty-eight consecutive patients with structural heart disease and clinical VTs were included and randomized to a simplified substrate ablation procedure with scar dechanneling as the first step (group 1, n = 24) or standard procedure with VT induction and ablation followed by scar dechanneling afterwards (group 2, n = 24). Thirty-eight patients had coronary artery disease, 10 non-ischemic cardiomyopathy and 1 arrhythmogenic right ventricular dysplasia. Prior to substrate ablation, 32 VTs were induced and targeted for ablation in 23 patients of the group 2. Procedure time (209 ± 70 min. vs. 262 ± 63 min., P = 0.009), fluoroscopy time (14 ± 6 min. vs. 21 ± 9 min, P = 0.005) and the need for electrical cardioversion (25% vs 54%, P = 0.039) were lower in group 1. After substrate ablation, 16 (66%) patients from group 1 and 12 (50%) from group 2 were non-inducible (P = 0.242). After residual inducible-VT ablation the percentage of patients with acute procedure success was 87.5% in group 1 and 70.8% in group 2 (P = 0.155). There were no differences in VT recurrence rate between groups during a mean follow-up of 22 ± 14 months (log rank P= 0.557). Conclusion: VT induction and mapping prior to substrate ablation prolongs the procedure, radiation exposure and the need for of electrical cardioversion; without benefit in terms of acute and long-term outcomes.

Substrate modification or ventricular tachycardia induction, mapping, and ablation as the first step? A randomized study

The role and optimal sequence of ventricular tachycardia (VT) induction, mapping, and ablation when combined with substrate modification is unclear. The purpose of this study was to test the benefits of starting the scar-related VT ablation procedure with substrate modification vs the standard protocol of VT induction, mapping, and ablation as the first step. Forty-eight consecutive patients with structural heart disease and clinical VTs were randomized to simplified substrate ablation procedure with scar dechanneling as the first step (group 1, n = 24) or standard procedure with VT induction, mapping, and ablation followed by scar dechanneling (group 2, n = 24). Procedure and fluoroscopy times, the need for external cardioversion, acute results, and VT recurrence during follow-up were compared between groups. Thirty-seven patients had ischemic cardiomyopathy, 10 nonischemic cardiomyopathy, and 1 arrhythmogenic cardiomyopathy. Before substrate ablation, 32 VTs were induced and targeted for ablation in 23 patients of group 2. Procedure time (209 ± 70 minutes vs 262 ± 63 minutes; P = .009), fluoroscopy time (14 ± 6 minutes vs 21± 9 minutes; P = .005), and electrical cardioversion (25% vs 54%; P = .039) were lower in group 1. After substrate ablation, 16 patients (66%) of group 1 and 12 patients (50%) of group 2 were noninducible (P = .242). End-procedure success (after residual inducible VT ablation) was achieved in 87.5% and 70.8% of patients, respectively (P = .155). There were no differences in VT recurrence rate between groups during a mean follow-up of 22 ± 14 months (log rank, P = .557). VT induction and mapping before substrate ablation prolongs the procedure, radiation exposure, and the need for electrical cardioversion without improving acute results and long-term ablation outcomes.

Usefulness of Pharmacologic Conversion of Atrial Fibrillation During Dofetilide Loading Without the Need for Electrical Cardioversion to Predict Durable Response to Therapy

Conversion of persistent atrial fibrillation (AF) to sinus rhythm is frequently seen during the 3-day in-hospital loading period required during dofetilide initiation, but it is not known whether pharmacologic conversion (PC) without the need for electrical cardioversion (EC) is a predictor of long-term maintenance of sinus rhythm during continued therapy with dofetilide. We sought to test the hypothesis that PC predicts durable maintenance of sinus rhythm and determine additional predictors of long-term maintenance of sinus rhythm on dofetilide. We retrospectively reviewed all elective inpatient admissions for dofetilide loading from 2003 to 2011 at the University of Virginia. A multivariate Cox proportional hazards model was used to assess predictors of maintenance of sinus rhythm after in-hospital dofetilide loading. In all, 101 patients with a current duration of AF lasting for a median of 1.86 months (interquartile range 0.47 to 6.03) were included in the analysis. Forty-seven patients were in the PC group, whereas 54 patients were in the EC group. Patients in the PC group remained longer in sinus rhythm compared with the patients in the EC group (log-rank p = 0.032). The seventy-fifth percentile for the current episode duration in the PC group was 5.77 months, indicating that even long-standing persistent AF frequently converted pharmacologically. Hypertension and a longer duration of the current AF episode were also predictors of recurrence in the multivariate model. In conclusion, PC during in-hospital dofetilide loading is an important predictor of durable response even in long-standing persistent patients, which has important public health implications for choice of therapy.

Echocardiographic predictors of frequency of paroxysmal atrial fibrillation (AF) and its progression to persistent AF in hypertensive patients with paroxysmal AF: Results from the Japanese Rhythm Management Trial II for Atrial Fibrillation (J-RHYTHM II Study)

Little is known about associations among echocardiographic variables, frequency of atrial fibrillation (AF), and progression from paroxysmal to persistent AF. The purpose of this study was to investigate echocardiographic predictors of frequency of paroxysmal AF and its progression to persistent AF in hypertensive patients with paroxysmal AF. We used data from 286 patients with paroxysmal AF and hypertension in the Japanese Rhythm Management Trial II for Atrial Fibrillation (J-RHYTHM II Study). Echocardiographic evaluation was performed at baseline. Endpoints were (1) percent of AF days measured daily by transtelephonic monitoring over 1 year and (2) development of persistent AF, defined as incidence of AF lasting for longer than 7 days and/or need for electrical cardioversion. Univariate and multivariate linear regression analysis was performed to evaluate the association between echocardiographic variables and percent of AF days. Cox proportional hazards analysis was used to examine the association between echocardiographic variables and development of persistent AF. Among echocardiographic variables, increased left atrial dimension (LAD) was associated with more AF days and development of persistent AF: a 10-mm increase in LAD was associated with a 6.5% increase in AF days (95% confidence interval 2.7%-10.3%) and an 84% increased risk of developing persistent AF (hazard ratio 1.84, 95% confidence interval 1.28-2.67). These associations remained significant after adjustment for age, sex, and other potential confounding factors. Increased LAD is associated with more AF days and progression from paroxysmal to persistent AF in patients with paroxysmal AF and hypertension. Increased LAD may be a good echocardiographic predictor of AF frequency and progression.

Pulmonary vein isolation and linear lesions in atrial fibrillation ablation

Various strategies have been used for atrial fibrillation (AF) ablation. It is unclear whether adding linear lesions to pulmonary vein (PV) isolation has significant advantages. We assessed the clinical benefit of adding linear lesions in patients undergoing PV isolation for AF. One hundred patients (63 male and 37 female; mean age of 59 +/- 11 years) with documented paroxysmal AF were included in the study. Patients were randomized into two groups. The first group underwent PV isolation alone. The second group underwent PV isolation and had two linear lesions created; one line between the superior PVs, and a second line from the left inferior PV to the mitral valve annulus. Patients' clinical progress after the ablation was evaluated and compared at 1, 3, and 9 months after their respective ablation procedures. The linear lesions group maintained sinus rhythm and had fewer symptoms than the lone PV isolation group (86 vs. 58%, respectively) (p < 0.05) at 1 month. At 9 months, when patients who reverted to AF underwent additional management to regain sinus rhythm (90 vs. 82%, respectively) (p = NS), there was no statistical difference between the groups regarding the use of antiarrhythmics, the need for electrical cardioversion, and subjective improvement. The addition of linear lesions to PV isolation more effectively achieved sinus rhythm initially and fewer patients required additional management to maintain their rhythm when compared to patients who underwent lone PV isolation. However, at 9 months, the overall results were similar in both groups.