Successful Direct Current Cardioversion Research Articles

Antiarrhythmic preferences and outcomes post DC cardioversion for atrial fibrillation, an Australian rural perspective.

Direct current cardioversion (DCCV) remains one of the recommended management strategies for symptomatic atrial fibrillation (AF). Antiarrhythmic drugs (AAD) are prescribed post procedure to maintain sinus rhythm (SR). Limited literature exists on the AAD prescribing practices and their efficacy, post-DCCV in rural Australia. The primary aim was to determine the preferred AAD post-DCCV and the factors affecting AAD prescribing practices. The secondary aim was to assess the efficacy of the AAD in maintaining SR. A retrospective observational audit of patients with non-valvular AF who underwent successful elective DCCV for symptomatic AF, during 2015-2020 at a regional hospital in New South Wales (NSW) (Dubbo Base Hospital). Patients were followed up for a duration of 12 months post-DCCV. 233 patients underwent successful DCCV during the study duration. Amiodarone was the preferred AAD of choice post-DCCV followed by sotalol and flecainide, respectively (36.5% vs. 27.8% vs. 1.3%). 35.2% patients were not prescribed AAD. Amiodarone and sotalol had similar but modest efficacies and neither were superior to no AAD, in maintaining SR 12 months post-DCCV (AF recurrence rate 61.5% vs. 68.2% vs. 71.6% respectively, p = 0.37). Antecedent cerebrovascular accident (CVA), pulmonary disease, smoking, prior treatment with digoxin, diuretics and left ventricular (LV) dysfunction were factors that influenced AAD prescribing practices. The study demonstrates equal efficacies of amiodarone, sotalol and no AAD in maintaining SR 12 months post-DCCV. Prescribing practices post-DCCV at Dubbo Base Hospital differ from observed national trends and guidelines. AAD prescription requires a multifaceted approach with a key consideration to prioritise safety over efficacy, being mindful of challenges in delivering optimal healthcare in a rural setting.

Predictors of Transthoracic Impedance in Patients Who Underwent Elective Electrical Cardioversion

Successful synchronized direct current cardioversion (DCCV) requires adequate current delivery to the heart. However, adequate current for successful DCCV is not yet established. Trans-myocardial current depends on two factors: input energy and transthoracic impedance (TTI). While factors affecting TTI have been studied in animal models, factors affecting TTI in humans have not been well established. Here we explored the potential factors that affect TTI in humans. Retrospective review of patients undergoing DCCV at a large quaternary medical center between October 2019 and August 2021 was conducted. Pertinent clinical information, including demographics, echocardiography findings, laboratory findings and body characteristics were collected. Cardioversion details including joules delivered and TTI were recorded by the defibrillator for each patient's first shock. Predictors of thoracic impedance were assessed using regression analysis. A total of 220 patients (29% female) were included in the analysis. 143 (65%) of the patients underwent DCCV for atrial fibrillation, 77 (35%) underwent DCCV for atrial flutter. Mean impedance in our population was 73 ± 18 ohms. In a regression model with high impedance defined as the upper quartile of our cohort, BMI, female sex, obstructive sleep apnea and chronic kidney disease (All p values <0.05) were significantly associated with high impedance. According to an ROC analysis, BMI has a high predictive value for high impedance, with an AUC of 0.76. In conclusion, our study reveals that elevated BMI, female sex, sleep apnea and chronic kidney disease were predictors of higher TTI. These factors may help in determining the appropriate initial shocking energy in patients undergoing DCCV for atrial fibrillation and flutter.

Abstract 14165: Left Atrial Appendage Emptying Velocity as a Predictor of Energy Required for Successful DC Cardioversion in Patients With Atrial Fibrillation

Background: Atrial fibrillation (AF) is a prevalent cardiovascular disease in the elderly population. Restoring sinus rhythm in AF often involves antiarrhythmic drugs, direct current (DC) cardioversion, and ablation. The predictive value of left atrial appendage (LAA) emptying velocity in determining the energy required for successful DC cardioversion remains uncertain. Aim: To study the association between LAA emptying velocity and the amount of energy required for cardioversion in patients with AF undergoing DC cardioversion. Methods: A total of 79 consecutive AF patients were enrolled in the study. Transesophageal echocardiography was performed to exclude the presence of clot formation, after which patients underwent DC cardioversion using escalating biphasic energy levels of 100 joules, 200 joules, and 360 joules to restore sinus rhythm. Patients were stratified into two groups based on LAA emptying velocity: the low-velocity group (≤30 cm/sec) and the high-velocity group (&gt;30 cm/sec). Clinical characteristics were compared between the groups. Results: Of the 79 patients, 49 had a low LAA emptying velocity (LAAEV). The low-velocity group was older, with a mean age of 75 years compared to 70 years in the high-velocity group. The severity of mitral regurgitation was similar between the two groups. Patients with reduced LAA emptying velocity required significantly higher joules for successful cardioversion compared to the high-velocity group (192 joules vs. 155 joules, p-value = 0.02). Sleep apnea was more prevalent in the high-velocity group. The utilization of antiarrhythmic medications did not differ significantly between the groups (55% vs. 63%, p-value = 0.25). Conclusions: The study showed AF patients with low LAA emptying velocity require higher energy levels for successful cardioversion, suggesting that LAA emptying velocity may serve as a predictor of energy requirement in DC cardioversion for restoring sinus rhythm in AF patients.

Comparative Effectiveness of Direct Current Cardioversion in Patients With Atrial Fibrillation and Obesity With Body Mass Index ≥50 kg/m2

Atrial fibrillation is one of the most frequently encountered arrhythmia, with obesity being an independent risk factor. There are sparse data on the success rates of direct current cardioversion (DCCV) in patients with severe obesity. We compared the effectiveness of DCCV in patients with a body mass index (BMI) >50kg/m2 with those with a BMI <30kg/m2. A retrospective chart review of 111 patients was performed between January 1, 2011 and January 1, 2022. The study cohort was stratified into 2 groups: BMI ≥50kg/m2 and BMI <30kg/m2. The primary outcome was successful achievement of normal sinus rhythm after DCCV. The secondary outcomes included number of attempted shocks, number of successful shocks on first attempts, and energy of successful shock. The primary outcome occurred in 94.6% of patients with a BMI <30kg/m2 group compared with 81.8% in the patients with a BMI ≥50kg/m2 (p=0.042). Patients in the higher BMI cohort had a higher median energy during a successful shock than the lower BMI cohort (250J [200 to 360J] vs 200J [150 to 200J], p <0.001). There was no difference in the number of shocks used between the 2 groups or in the success of the first shock delivered between BMI ≥50kg/m2 and BMI <30 kg/m2 (75% vs 58.2%, p=0.093). In conclusion, patients with a BMI ≥50kg/m2 had lower rates of successful DCCV than patients with a BMI <30kg/m2; therefore, clinicians must be aware of the alternative strategies to improve DCCV success and the possibility of DCCV failure in patients with higher BMIs.

The efficacy and safety of a nurse-led electrical cardioversion service for atrial fibrillation over a 2-year time period.

Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia worldwide, with a significant impact on morbidity, mortality, and utilization of healthcare resources. Electrical direct-current cardioversion (DCCV) is offered to patients with ongoing symptoms despite medical management. In this study, we aim to evaluate the safety and efficacy of a specialized nurse-led DCCV service. This was a retrospective cohort study analysing the outcome of patients presenting with AF or flutter, who were subsequently referred for a nurse-led DCCV procedure between August 2017 and December 2019. Analysis included a total of 341 patients (mean age = 68.37; standard deviation = 10.96) who presented with either AF (N = 267; 78.30%) or atrial flutter (N = 74; 21.70%). Approximately 30% of patients were females (N = 101) and 70% were males (N = 240). Of the 341 patients who underwent DCCV, 299 were successfully cardioverted (87.68%). Of those patients successfully cardioverted, 167 remained in sinus rhythm after 6 weeks (55.85%); 93 patients reverted back to AF (31.10%). Thirty-eight patients were lost to follow up (12.71%). Of all 341 patients who underwent DCCV, only 24 patients were admitted to hospital during the subsequent 3-month period (7.04%). Importantly, no patients were admitted as a direct complication of the DCCV procedure. Overall, data gathered from this study provides positive evidence to support the use of a nurse-led DCCV service. In addition to obtaining very successful cardioversion rates, we found low remission rates, with a very low hospital readmission rate for AF-related issues after successful DCCV.

Usefulness of the systemic immune-inflammation index in predicting atrial fibrillationrecurrence after direct current cardioversion.

Background: We aimed to determine whether there is a relationship between thesystemic immune-inflammation (SII) index and the recurrence of atrial fibrillation (AF) after successful direct current cardioversion (DCCV). Methods: The study included 99 patients with persistent AFwho underwent successful cardioversion between 2015 and 2020. Results: In multiple regression analyses, the SII index was found to be a better independent predictor of AF recurrence after successful DCCV (p<0.001). The cut-off value of SII (563) was associated with 96.9% sensitivity and 55.2% specificity to predict AF recurrence after DCCV. Conclusion: As a simple biomarker, SII index is an independent parameter for predicting AF recurrence after successful DCCV in patients with persistent AF. Also, SII levels can predict AF recurrence better than neutrophil-to-lymphocyte ratio.

Early improvement of cardiac performance after atrial fibrillation direct current cardioversion

Abstract Funding Acknowledgements Type of funding sources: None. Background Atrial fibrillation (AF) is the most common arrhythmia and one of the most prevalent cardiac disease. Restoring sinus rhythm improves long-term systolic and diastolic function, quality of life and relieve symptoms in patients with symptomatic AF. Purpose The aim of the study was to evaluate the early effects of AF direct current cardioversion on myocardial deformation using speckle-tracking echocardiography. Methods 51 patients with persistent AF who underwent successful direct current cardioversion were enrolled (age: 70 ± 9 years; men: 72.5%). Patients with ischemic, dilatative, hypertrophic cardiomyopaties, valvular heart disease, previous cardiac interventions were excluded from the study. Left ventricular ejection fraction was 55.2 ± 7.0%. A transthoracic echocardiography was performed one day before the successful cardioversion and 6 hours after, employing 2d standard echocardiography and speckle-tracking technique to evaluate left atrial, left ventricular and free-wall right ventricular longitudinal strain. Results Restoration of sinus rhythm led to a reduction of the heart rate (83 ± 14 vs 70 ± 13 bpm, p &amp;lt; 0.001). After about six hours from successful AF direct current cardioversion, we highlighted an increase in left ventricular filling pressure estimated with the ratio E/E’ (8.19 ± 0.29 vs 9.34 ± 0.41, p = 0.0016). A significant increase in left atrial longitudinal strain (10.47 ± 0.64% vs 19.76 ± 1.01%, p &amp;lt; 0.001, Figure A) and in left ventricular longitudinal strain (-13.10 ± 0.60% vs -15.86 ± 0.51%, p &amp;lt; 0.001, Figure C) were noticed; also the free wall right ventricular longitudinal strain increased (-12.06 ± 1.16% vs -15.86 ± 1.29%, p = 0.047, Figure B). Conclusion Restoring sinus rhythm improves cardiac performance as evidenced by the increase in either left atrial and bi-ventricular longitudinal strain, suggesting an amelioration even if after early time. Abstract Figure

Abstract 12254: Predictors of Transthoracic Impedance in Patients Undergoing Electrical Cardioversion

Introduction: Successful synchronized direct current cardioversion (DCCV) requires adequate current delivery to the heart. However, adequate current for successful DCCV is not yet established. Trans-myocardial current depends on two factors: input energy and transthoracic impedance (TTI). While factors affecting TTI have been studied in animal models, factors affecting TTI in humans have not been well established. Here we explored potential factors that affect TTI in humans. Methods: Retrospective review of consecutive patients undergoing DCCV at a large quaternary medical center between October 2019 and December 2020 was conducted. Pertinent clinical information, including demographics, echocardiography findings, laboratory findings and body characteristics were collected. Cardioversion details including joules delivered and TTI were recorded by the defibrillator for each patient’s first shock. Predictors of thoracic impedance were assessed using multivariable regression analysis after adjustment for confounders. Results: A total of 180 patients were analyzed, 31% of which were female. Mean impedance was 73.15 ± 21.50 (range 39-208). In multivariate analysis, higher TTI was significantly associated with higher BMI (p&lt;0.001, Figure ) and female gender (p=0.006) after adjustment for all confounders. Other factors including age, history of cardiac surgery, left ventricular ejection fraction, left atrial size, brain natriuretic peptide, and antero-posterior chest diameter were not associated with TTI. Conclusion: Our results align with prior studies that body habitus and gender affect TTI and suggest that adjustments in input energy based on these factors may be required for appropriate trans-myocardial current delivery in synchronized cardioversion.

B-PO05-201 IMMEDIATE RECURRENCE OF ATRIAL FIBRILLATION AS A PREDICTOR OF LONG TERM ATRIAL FIBRILLATION RECURRENCE FOLLOWING DIRECT CURRENT CARDIOVERSION

Immediate recurrence of AF (IRAF) is a common cause of direct current cardioversion (DCC) failure, and long-term recurrence of AF (LRAF) frequently occurs after a successful DCC. Identification of modifiable factors associated with IRAF and LRAF might improve overall success of DCC for atrial fibrillation. We sought to identify modifiable factors associated with IRAF and LRAF. We used logistic regression to determine factors associated with IRAF and a cox proportional hazards model to determine factors associated with LRAF. Given the low number of IRAF events, factors for that analysis were selected from a list of 94 (7 baseline vitals, 10 cardiac parameters, 9 cardiac diseases, 43 medications, 11 cardiac procedures, and 7 demographic variables) using elastic net regularization. First time cardioversions (n = 4202) in our institutional EP lab database from September 2012 to September 2017 were included in the analysis. IRAF (n = 432) was associated with increased heart rate (OR 1.01 per beat/min, p = 0.009) and was a significant predictor of LRAF (n = 2551) (median follow-up time 3.65 months) (HR 1.84 (95% CI 1.54-2.21) p < 0.001) (Figure). Other modifiable factors associated with LRAF included dofetilide use (HR 1.22 (95% CI 1.02-1.45) p < 0.001) and apixaban use (HR 0.82 (95% CI 0.69 - 0.97) p = 0.020). IRAF was associated with higher heart rate in AF, suggesting that better rate control at the time of DCC might reduce IRAF. IRAF was associated with LRAF after DCC. As pulmonary vein (PV) triggers have been postulated to cause IRAF, the presence of IRAF may support PV isolation as a strategy for prevention of recurrent AF.

The efficacy and safety of a nurse-led electrical cardioversion service for atrial fibrillation over a two-year time period

Abstract Funding Acknowledgements Type of funding sources: None. Background &amp; Purpose Atrial fibrillation (AF) is the most prevalent cardiac arrhythmia worldwide, with a significant impact on morbidity, mortality and utilisation of healthcare resources. Electrical direct-current cardioversion (DCCV) is offered to patients with ongoing symptoms despite medical management. In this study we aim to evaluate the safety and efficacy of a specialised nurse-led DCCV cardioversion service. Methods This was a retrospective cohort study analysing the outcome of patients presenting with atrial fibrillation or flutter, who were subsequently referred for a nurse-led DCCV procedure between August 2017 and December 2019. Results Analysis included a total of 341 patients (mean age = 68.37; STDV = 10.96) who presented with either atrial fibrillation (N = 267; 78.30%) or atrial flutter (N = 74; 21.70%). Approximately 30% of patients were female (N = 101); and 70% were male (N = 240). Of the 341 patients who underwent DCCV, 299 were successfully cardioverted (87.68%), whilst 42 patients remained in AF (12.32%). Of those patients successfully cardioverted, 167 remained in sinus rhythm after 6 weeks (55.85%); 93 patients reverted back to AF (31.10%). 38 patients were lost to follow up (12.71%). Of all 341 patients who underwent DCCV, only 24 patients were admitted to hospital during the subsequent 3 month period (7.04%). Of these admissions, 11 were due to persistent AF (45.83%), and 13 were due to other non-related reasons (54.17%). Importantly, no patients were admitted as a direct complication of the DCCV procedure. Using a Chi-squared analysis, we found a significant difference in cardioversion success rates between patients presenting with atrial flutter (97% success rate) versus those in atrial fibrillation (85% success rate) (χ2 = 8.089; p = 0.004; α&amp;lt;0.05). We did not find a significant difference in cardioversion success rates between males and females (χ2 = 1.651; p = 0.199; α&amp;lt;0.05); nor did we witness a significant impact from the presence of ischaemic heart disease (χ2 = 1.545; p = 0.214; α&amp;lt;0.05) or hypertension (χ2 = 2.075; p = 0.150; α&amp;lt;0.05). Similarly, we found negligible impact of LV ejection fraction (χ2 = 1.494; p = 0.684; α&amp;lt;0.05) or LA size (χ2 = 1.310; p = 0.727; α&amp;lt;0.05) upon cardioversion success rates. We witnessed a dramatic improvement in DC cardioversion success rates in patients taking antiarrhythmic medication in preference to a rate control strategy alone (χ2 = 11.825; p = 0.008; α&amp;lt;0.05). Conclusion Overall, data gathered from this study provides positive evidence to support the use of a nurse-led DCCV service. In addition to obtaining very successful cardioversion rates, we found low remission rates, with a very low hospital readmission rate for AF related issues after successful DCCV.

The Impact of Personal Thoracic Impedance on Electrical Cardioversion in Patients with Atrial Arrhythmias.

Background and Objectives: Direct current cardioversion (DCCV) is a safe and useful treatment for atrial tachyarrhythmias. In the past, the energy delivered in DCCV was decided upon empirically, based only on the type of tachyarrhythmia. This conventional method does not consider individual factors and may lead to unnecessary electrical damage. Materials and Methods: We performed DCCV in patients with atrial tachyarrhythmias. The impedance and electrical current at the moment of shock were measured. The human thoracic impedance between both defibrillator patches and the electric current that was used were measured. Results: A total of 683 DCCVs were performed on 466 atrial tachyarrhythmia patients. The average impedance was 64 ± 11 Ω and the average successful current was 23 ± 6 mA. The magnitude of the electrical current that was successful depended upon the human impedance (linear regression, B = −0.266, p < 0.001) and the left atrial diameter (B = 0.092, p < 0.001). Impedance was directly proportional to body mass index (BMI) (B = 1.598, p < 0.001) and was higher in females than in males (77 ± 15 Ω vs. 63 ± 11 Ω, p < 0.001). Notably, the high-impedance (>70 Ω) group had a higher BMI (27 ± 4 kg/m2 vs. 25 ± 3 kg/m2, p < 0.001) and a higher proportion of females (37% vs. 9%, p < 0.001) than the low-impedance group (<70 Ω). However, thoracic impedance was not an independent predictor for successful DCCV. Conclusions: Human thoracic impedance was one of the factors that impacted the level of electrical current required for successful DCCV in patients with atrial arrhythmias. In the future, it will be helpful to consider individual predictors, such as BMI and gender, to minimize electrical damage during DCCV.

Left atrial wall dyskinesia assessed during contractile phase as a predictor of atrial fibrillation recurrence after electrical cardioversion performed due to persistent atrial fibrillation

Direct current cardioversion (DCCV) is one of the basic methods for restoring sinus rhythm (SR) in patients with atrial fibrillation (AF). Left atrial (LA) strain is one of the parameters used to assess the risk of AF recurrence following DCCV. Assessing the strain also allows for the detection of segmental disorders of LA wall contractility, including dispersion or dyskinesia. In the present study, we determined the predictive value of LA wall dyskinesia in assessing the risk of AF recurrence after DCCV. We performed a comprehensive echocardiography in 89 patients with persistent AF following successful DCCV. We assessed the strain and strain rate in the reservoir (r), conduit, and contractile (ct) phases by using speckle tracking echocardiography. Dyskinesia was diagnosed when the strain rate of any segment of the LA wall displayed positive values during contraction. After 12 months, 47.2% of patients maintained SR. Patients who maintained SR had a significantly lower LA strain (LAS)r assessed in the apical 4-chamber view (4c) (11.38 ± 4.63 vs 14.54 ± 5.11; P = .004) and 2-chamber view (2c) (11.05 ± 4.1 vs 14.93 ± 6.82%; P = .006), LASct4c (2.51 ± 2.3 vs 5.09 ± 3.29%; P < .001), LASct2c (3.6 ± 2.98 vs 5.67 ± 4.23%; P = .008), peak strain rate (pLASR) ct4c (0.36 ± 0.24 s vs 0.62 ± 0.4−1; P < .001) and pLASRct2c (0.49 ± 0.30 vs 0.79 ± 0.53 s−1; P = .01). LA dyskinesia was observed less frequently in the 4c view in patients who maintained SR (59.57 vs 17.5%; P < .001). Multivariable logistic regression showed that the LASct4c (odds ratio (OR) 0.78; 95%CI 0.63–0.97; P = .027) and LA dyskinesia observed in the 4c view (OR 3.53; 95%CI 1.16–10.76; P = .027) were significant independent predictors of AF recurrence at 12 months. We conclude that LA dyskinesia observed in the 4c view and LASct4c are independent risk factors for AF recurrence following DCCV.

Left atrial emptying fraction determined during atrial fibrillation predicts maintenance of sinus rhythm after direct current cardioversion in patients with persistent atrial fibrillation.

Echocardiography is the basic imaging technique used to determine the odds of maintaining sinus rhythm (SR) following direct current cardioversion (DCCV) for persistent atrial fibrillation (AF). However, most studies are focused on the echocardiographic parameters obtained during SR resulting from successful DCCV. The aim of this study was to assess the value of the echocardiographic parameters measured before DCCV for the prognosis of SR maintenance after DCCV. The study included 146 patients with persistent AF who underwent DCCV. Clinical and echocardiographic data were collected directly before DCCV and, for patients with SR, one month, six months, and 12 months after DCCV. We found that left atrial emptying fraction (LAEF) assessed during atrial fibrillation was significantly larger in the group with SR maintenance after 12 months than in the group with AF recurrence (30.8±8.3 vs. 24.6±10.4%; p<0.001). In multivariable logistic regression analysis with a model containing echocardiographic parameters, LAEF (OR 1.053; 95% CI 1.011-1.096; p = 0.013) and the E/e'mean ratio (OR 0.883; 95% CI 0.788-0.990; p = 0.033) were independent predictors of SR maintenance. Analyzing a model including clinical and echocardiographic variables, only LAEF (OR 1.046; 95% CI 1-1.095; p = 0.049) and beta-blockers used before DCCV (OR 14.694; 95% CI 1.622-133.139; p = 0.017) were independent predictors of SR maintenance after 12 months. Our results indicate that LAEF measured during AF is a significant predictor of SR maintenance in the 12 months following DCCV due to persistent AF. Our findings confirm the recently raised hypothesis about the superiority of echocardiographic parameters assessing mechanical remodeling over parameters assessing structural remodeling of left atrium in predicting sinus rhythm maintenance after electrical cardioversion.

Safety and Effectiveness of Electrical and Pharmacological Cardioversion in Persistent Atrial Fibrillation. Part I: Study Rationale, Design and Assessment of Effectiveness

Aim. We aimed to compare effectiveness of new class III antiarrhythmic drug Refralon with direct current cardioversion (DCC) in patients with persistent atrial fibrillation (AF). Material and methods. 60 patients with persistent AF were randomized to groups of DCC (n=30) and pharmacologic conversion (PCV; n=30). There were no differences in age, sex, AF duration, concomitant cardiovascular diseases, CHA2DS2-VASc score and echocardiographic parameters between the groups compared. Initial assessment excluded contraindications to restore sinus rhythm (SR). In DCC group two attempts using biphasic synchronized shocks of 150 J and 170 J were performed. In PCV group patients received up to three subsequent intravenous injections of Refralon 10 μg/kg (maximal dose 30 μg/kg). Results. SR was restored in 27 of 30 patients (90%) in DCC group and in 28 of 30 patients (93.3%) in PCV group. 95% confidence interval (CI) for primary effectiveness criterion was [-0.1 – 0.16]. AF recurred in 1 patient after successful DCC. There were no AF recurrences in PCV group. 26 of 30 patients (86.7%) in DCC group and 28 of 30 patients (93.3%) in PCV group remained in SR 24 hours after cardioversion. 95%CI for secondary effectiveness criterion was [-0.07 – 0.19]. Conclusion. Effectiveness of Refralon is noninferior to DCC in patients with persistent AF.

Handheld Ultrasound as a Novel Predictive Tool in Atrial Fibrillation: Prediction of Outcomes Following Electrical Cardioversion.

BackgroundAtrial fibrillation (AF) recurrence after successful direct current cardioversion (CV) is common, and clinical predictors may be useful. We evaluated the risk of early AF recurrence according to inferior vena cava (IVC) measurements by handheld ultrasound (HHU) at the time of CV.ObjectiveAssess HHU and objectively obtained measurements acquired at the point of care as potential clinical predictors of future clinical outcomes in patients with AF undergoing CV.MethodsMaximum IVC diameter (IVCd) and collapsibility with inspiration were measured by the Vscan HHU (General Electric Healthcare Division) in 128 patients immediately before and after successful CV for AF. Patients were followed by chart review for recurrence of AF.ResultsMean IVCd was 2.16 cm in AF pre-CV and 2.01 cm in sinus rhythm post-CV (P<.001). AF recurred within 30 days of CV in 34 of 128 patients (26.6%). Among patients with IVCd <2.1 cm pre-CV and decrease in IVCd post-CV, AF recurrence was 12.1%, compared to 31.6% in patients not meeting these parameters (odds ratio [OR] 0.299, P=.04). This association persisted after adjustment for age, ejection fraction <50%, left atrial enlargement, and amiodarone use (adjusted OR 0.185, P=.01). Among patients with IVCd post-CV <1.7 cm, AF recurrence was 13.5%, compared to 31.9% in patients not meeting this parameter (OR 0.185, P=.01). IVC parameters did not predict AF recurrence at 180 or 365 days.ConclusionsThe presence of a normal IVCd pre-CV that becomes smaller post-CV and the presence of a small IVCd post-CV were each independently associated with reduced likelihood of early, but not late, AF recurrence. HHU assessment of IVCd at the time of CV may be useful to identify patients at low risk of early recurrence of AF after CV.

Apelin and Atrial Fibrillation: The Role in the Arrhythmia Recurrence Prognosis.

Apelin is a novel peptide of wide expression and multiple biological functions including the crucial role in cardiovascular homeostasis. The apelin role in the pathophysiology of heart rhythm disorders is considered, although the reports are scarce so far. The purpose of this study is to investigate the potential utility of apelin as a marker of arrhythmia recurrence after direct-current cardioversion (DC). The prospective, observational study included 60 patients (aged 41–86; 30% female) with nonvalvular, persistent atrial fibrillation from the group of 204 consecutive patients scheduled for DC during the 12-month period (from May 2010 to May 2011) in the Cardiology Clinic Medical University of Lodz, Poland. The study group was divided into SCD (successful DC), 45 (75%) patients, and NDC (nonsuccessful DC), 15 (25%) patients. Within the SCD group, the subgroups were distinguished depending on the time sinus rhythm maintenance after DC: up to 7 days (SDC-7), 11 patients; 7 to 30 days (SDC-30), 12 patients; over 90 days (SDC-90), 22 patients. Patients were evaluated during the hospitalization and within the 3-month follow-up period. The apelin level was determined within the plasma samples collected at the admission, using the commercially available enzyme-linked immunosorbent assay (ELISA) Kit for apelin-36. It was found that the median value of initial apelin in the subset of patients from groups NDC + SDC-7 + SDC-30 is significantly higher than from group SDC-90 (p = 0.0463); there was no relationship between NDC and SCD overall. Neither of the compared subgroup pairs revealed statistically significant correlation between the proBNP concentration and the DC effectiveness in our population. In conclusion, in our study, proBNP was not a marker of arrhythmia recurrence whereas higher apelin concentration at the admission indicated patients in whom DC was not effective or they had an arrhythmia recurrence within a month-period observation.

Left Atrial Sphericity Index Predicts Early Recurrence of Atrial Fibrillation After Direct-Current Cardioversion: An Echocardiographic Study.

Attempts to achieve rhythm control using direct-current cardioversion (DCC) are common in those with persistent atrial fibrillation (AF). Although often successful, AF recurs within 1 month in as many as 57% of patients. The aim of this study was to assess whether a baseline left atrial sphericity index (LASI) acquired by 2-dimensional transthoracic echocardiography (TTE) could be used as a predictor of AF recurrence after successful DCC. A baselline LASI assessed by 2D TTE can predict AF recurrence after successful DCC in patients with persistent AF. A total of 124 consecutive patients with persistent AF lasting <120 days underwent successful DCC. Other than β-blockers, no other antiarrhythmic treatment was administered. Prior to DCC, all patients underwent thorough TTE, and LASI was calculated as the fraction of the left atrial width/length of the largest possible left atrial volume in a 4-chamber view. The primary outcome was a TTE-estimated baseline LASI as a predictor of AF recurrence after successful DCC for persistent AF. Anatomically, a more spherical shape of the left atrium (LASI >0.9) proved to be a strong and independent predictor of AF recurrence, with an odds ratio between 4.1 (95% confidence interval: 1.6-11.9, P = 0.005) and 7.6 (95% confidence interval: 3.3-19.7; P = 7.2 × 10(-6) ). The receiver operating characteristic curve indicated good power for distinguishing between recurring and nonrecurring AF, and we chose a cutoff of 0.9 because high specificity was a priority for clinical reasons. In conclusion, baseline LASI >0.9 was associated with significantly greater AF recurrence throughout the 12-month follow-up period.

Effect of Early Direct Current Cardioversion on the Recurrence of Atrial Fibrillation in Patients With Persistent Atrial Fibrillation

In patients with persistent atrial fibrillation (AF), the sinus rhythm (SR) can be restored by direct current cardioversion (DCC), although the recurrence of AF after successful DCC is common. We examined whether transesophageal echocardiography (TEE)-guided early DCC, compared with the conventional approach of DCC after 3 weeks of anticoagulation with dabigatran-etexilat, reduces the recurrence of AF. A total of 126 consecutive patients with persistent AF were randomly assigned to a TEE followed by early DCC (n = 65) or to a conventional treatment with dabigatran-etexilat for 3 weeks followed by DCC (n = 61). None of the patients received any antiarrhythmic treatment other than β blockers, and all the DCCs were successful. Forty-eight-hour Holter monitoring was performed at 28 days and at 3, 6, and 12 months after the DCC. The primary outcome was AF recurrence lasting ≥30 seconds. The analysis was stratified by AF duration <60 (n = 62) or >60 days (n = 64) before DCC. We observed a significant reduction in the AF recurrence risk (p = 0.003) in patients with persistent AF <60 days who received early DCC, but there was no significant benefit of early DCC (p = 0.456) in patients with persistent AF lasting >60 days. The recurrence-free survival probability at 28 days in patients with persistent AF <60 days was 0.27 (95% confidence interval 0.14 to 0.51) in the conventional treatment group compared with 0.69 (95% confidence interval 0.54 to 0.87; p = 0.006) in the early DCC group. A benefit of early DCC persisted throughout 12 months of follow-up. In conclusion, TEE-guided early DCC in patients with persistent AF <60 days results in a significant reduction of AF recurrence.

Relationship between brain natriuretic peptides and recurrence of atrial fibrillation after successful direct current cardioversion: a meta-analysis.

Atrial fibrillation (AF) recurrence is common after successful direct current cardioversion (DCCV), with a 40% rate of recurrence within the first month. Several studies have investigated the potential association between brain natriuretic peptide (BNP) or N-terminal (NT)-proBNP levels before DCCV and the risk of AF recurrence, but results have been inconsistent. We, therefore, conducted a systematic review and meta-analysis of all available data to determine whether sinus rhythm (SR) maintenance after successful DCCV may be determined by preprocedural BNP and NT-proBNP levels. We systematically searched Scopus, the Cochrane library, EMBASE, and MEDLINE databases to identify publications evaluating BNP or NT-proBNP levels in relation to post-DCCV AF recurrence, indexed from inception to September 2013. Among the initial 1,067 citations, 18 studies fulfilled the specified criteria. The difference in BNP and NT-proBNP concentrations in the AF recurrence and the SR-maintaining group was estimated by the standardized mean difference and the estimates of the pooled outcomes were evaluated using random-effects models. Baseline BNP levels in the AF recurrence group were significantly higher compared to BNP levels in the SR-maintaining group (standardized mean difference [SMD] -1.51, confidence interval [CI] [-2.53, -0.48], P = 0.004). Similar results were observed for NT-proBNP levels, which were significantly higher in the AF recurrence group compared with the SR-maintaining group (SMD -0.63, CI [-1.13, -0.14], P = 0.01). Our analysis suggests that low preprocedural BNP/NT-proBNP levels are associated with SR maintenance. The use of BNP or NT-proBNP for prediction of long-term response to DCCV appears to be useful and should be further evaluated.

Safety of Short-Term Use of Dabigatran or Rivaroxaban for Direct-Current Cardioversion in Patients With Atrial Fibrillation and Atrial Flutter

Direct-current cardioversion (DCCV) for persistent atrial fibrillation or atrial flutter (AF) carries a risk of thromboembolic events (TEs). Therapeutic anticoagulation with warfarin is recommended for 3 to 4 weeks before and 4 weeks after DCCV to reduce TE; however, the safety of short-term anticoagulation with the novel oral anticoagulants (dabigatran and rivaroxaban) before DCCV has not been assessed. A retrospective cohort study was performed on all patients undergoing elective DCCV for AF at Northwestern Memorial Hospital from June 1, 2012 to September 30, 2013. Inclusion criteria included patients taking any of the novel oral anticoagulants for 21 to 60 days before DCCV and successful DCCV to sinus rhythm. Patients were monitored for a minimum of 60 days after DCCV to evaluate for TEs including stroke, transient ischemic attack, systemic emboli, and death. In total, 53 patients (47 men, 89%; age 65±10 years, median 66) were evaluated. Agents used were dabigatran (30 patients, 57%) and rivaroxaban (23 patients, 43%) for an average of 38±9 days. The mean CHADS2 score was 1.2±1.1 (score=0, 26%; 1, 43%; 2, 17%; and >3, 13%). Eleven patients (21%) underwent a transesophageal echocardiography before their DCCV; all showed no thrombus. No patients were found to have episodes of TE within 60 days of DCCV. No patients were found to have major bleeding events. In conclusion, the use of short-term dabigatran or rivaroxaban therapy for DCCV of AF appears safe.