Cardioversion In Patients Research Articles

External cardioversion of atrial fibrillation and flutter in patients with cardiac implantable electrical devices.

Atrial fibrillation and flutter are often treated with external electrical cardioversion (ECV) in patients with potentially electrically sensitive cardiovascular implantable electronic devices (CIED). Long-term follow-up data on contemporary CIED undergoing ECV is sparse. The aim is to investigate shock-related complications and impact on CIEDs. All ECV procedures from 2010 to 2020 in patients with CIED performed at a tertiary university hospital were identified in the Danish National Patient Registry. Changes in device measurements after ECV were retrospectively studied and procedure-related complications were identified by review of medical records. We analyzed 763 ECV procedures in 372 patients, median device implant time 1.9years. The mean age of patients was 69.9±9.9years of which 73.4% were men. We identified two cases of device programming changes and four cases of premature battery depletion (≤3years after device implant). Minor changes in device measurements were found for impedances, sensing, and pacing thresholds. No patients died due to ECV-related device dysfunctions within the first 12 months after cardioversions. External cardioversion in patients with contemporary pacemakers and implantable cardioverter-defibrillators seems safe in the majority of patients. Clinically important changes in device function following cardioversion were rarely observed but may be critical for device function. In an observational study, causality between cardioversion and device dysfunction cannot be established. For patient safety, we suggest that routine device interrogation after cardioversion still should be part of standard care.

Utility of Soluble ST2 biomarker to predict recurrence after electrical cardioversion in patients with atrial fibrillation

Abstract Background Atrial fibrillation (AF) is the more frequent arrhythmia in clinical practice. The ST2S is a biomarker that has demonstrated to be predictor of cardiovascular outcomes in patients with heart failure but there is scarce information of his utility in patients with AF. Purpose Considering the characteristics of the ST2S we hypothesize this biomarker could correlate to recurrence in patients with AF and electrical cardioversion (ECV). Methods This was an observational and prospective clinical trial. We compared all patients with AF referred for ECV with a control group without AF, from September 1th 2016 to September 30 2019. Clinical, ECG, echocardiographic and ST2S levels were analyzed in both groups at basal, at 3 and 6 months of follow-up in such cases with AF. Patients with inflammatory or allergic diseases, moderate/severe ventricular dysfunction, structural cardiomyopathy, moderate/severe hepatic, renal or respiratory disease were excluded. Results We included a total of 94 patients with AF and 40 paired controls. Clinical variables are presented in Table 1. Fifty-eight (61.7%) patients with AF had recurrence at follow-up. There was a significant difference between the ST2S levels at baseline between AF patients (17163.8 pg/mL) and controls (11016.2 pg/mL) (p=0.001). ST2S biomarker levels at 3 and 6 months of follow-up decreased in those patients without AF recurrence as shown in Figure 1. Covariable models were performed and ST2S biomarker levels at 3 months were significant to predict recurrence at 6 months follow-up (Table 2). The calculated cut-point of the biomarker was of 15511.51 pg/ml with a c-value: 0.669. Conclusions In our experience ST2S was a useful biomarker to predict recurrence of AF after ECV. Considering the size of the study more studies should be performed to confirm this results. Funding Acknowledgement Type of funding sources: None.

Bailout left atrial appendage occluder for pulmonary vein isolation and electrical cardioversion in patients with atrial fibrillation and left atrial appendage thrombus: a pilot study.

Cardioversion and catheter-based circumferential pulmonary vein isolation (CPVI) are established rhythm control treatment strategies for patients with atrial fibrillation (AF). However, these treatments are contraindicated for AF patients with a left atrial appendage (LAA) thrombus. We conducted the first-in-man case series study to evaluate the feasibility and safety of performing cardioversion or CPVI in AF patients with LAA thrombus immediately after implantation of LAA Occluder (LAAO) in a combined procedure. In our multi-center LAAO registry of 310 patients, 27 symptomatic and drug-refractory AF patients underwent a combined procedure of LAAO and CPVI, among whom 10 (mean age 68 ± 16years, 6 men) having anticoagulant-resistant LAA thrombus received a bailout procedure of LAAO implantation first then CPVI, and the other 17 patients without LAA thrombus received CPVI first then LAAO for comparison. The mean CHA2DS2-VASc score and HAS-BLED score were comparable between these two groups. In patients with LAA thrombus, we put carotid filters and did a no-touch technique, neither advancing the wire and sheath into the LAA nor performing LAA angiography. After LAAO implantation, the connecting cable was still connected to the occluder when cardioversion was performed. During CPVI, the occluder location was registered in the LA geometry by three-dimensional mapping to guide the catheter not to touch the LAAO. The procedure was successful in all the patients without intra-procedural complications. After a mean follow-up of 1.7 ± 0.7years, there was no device embolization, peri-device leak ≧ 5mm or stroke event in both groups. The AF recurrence rate was also similar between the two groups (P = 0.697). We demonstrated that cardioversion or CPVI is doable in symptomatic AF patients with LAA thrombus if LAA was occluded ahead as a bailout procedure.

Efficacy of Intraoperative Low Dose Intravenous Amiodarone in Pharmacologic Cardioversion in Patients with Preoperative Atrial Fibrillation Presenting for Mitral Valve Replacement Surgery Randomized Control Trial.

Atrial fibrillation (AF) is the most common form of dysrhythmia observed in the clinical field, causing multiple morbidities, such as thromboembolic complications. Hence, the maintenance of sinus rhythm is superior to rate control. This study tests the efficacy of single- and low-dose amiodarone on the persistence of AF after surgery before transfer to the intensive care unit. A double-blinded, randomized controlled trial assessed 113 patients who underwent mitral valve surgery with preoperative chronic AF. Patients were divided into two groups: the control group (N = 55) who received 50 mL of 5% dextrose over 10 min after general anesthesia induction, and the amiodarone group (N = 58) who received 1 mg/kg of amiodarone diluted in 50 mL of 5% dextrose over 10 min shortly after anesthesia induction. The amiodarone group had a statistically significant successful conversion of preoperative AF to normal sinus rhythm in 40 patients (72.73%). The control group demonstrated spontaneous conversion from AF to a normal sinus rhythm in seven patients (12.73%). The sinus rhythm was maintained in 60% of patients (36), as four patients reverted to AF during the hospital stay despite the initial normal sinus rhythm after the operation. In contrast, 53 (96.36%) patients in the control group were discharged from the hospital with a controlled rate of AF. In addition, low-dose amiodarone caused a statistically significant reduction in heart rates at 10, 30, and 60 min after declamping, extended throughout the first 24 h with mean heart rates of 97.233±7.311, 99.509±8.482, and 97.940±7.715 bpm, respectively. In comparison, the control group had heart rates of 115.382±7.547, 115.055±13.919, and 113.618±8.765 bpm at these times. The mean postoperative heart rate at the end of the first 24 h was 97.793±7.189 bpm in the amiodarone group and 113.036±9.737 bpm in the control group. No mortality or need for mechanical support was recorded in either group. Single and low-dose intraoperative intravenous amiodarone during mitral valve surgery may be practical to aid in pharmacological cardioversion of patients with preoperative chronic AF presenting for mitral valve surgery.

Pharmacological Cardioversion in Patients with Recent-Onset Atrial Fibrillation and Chronic Kidney Disease Subanalysis of the CANT II Study.

Pharmacological cardioversion (PCV) is commonly a primary option for termination of recent-onset atrial fibrillation (AF) in emergency departments (ED). This is a subanalysis of the CANT II study, evaluating the effectiveness and safety of antazoline in patients (n = 777) at three stages of chronic kidney disease (CKD): Group I > 60 mL/min (n = 531), Group II 45–59 mL/min (n = 149), and Group III < 45 mL/min (n = 97). Patients in Group III were older and with a higher prevalence of co-morbidities; however, we did not find statistically significant differences in the overall effectiveness of PCV in comparison with the other groups. In patients receiving amiodarone, the PCV success rate was similar in all the studied groups, but along with a renal function decline, it decreased in patients receiving antazoline (79.1 vs. 35%; p < 0.001), and it increased almost significantly in patients receiving propafenone (69.9 vs. 100%; p = 0.067). In patients in Group I, antazoline restored a sinus rhythm as effectively as propafenone and amiodarone; however, in patients in Group III, both antazoline and amiodarone became less effective in restoring a sinus rhythm than propafenone (p = 0.002 and p = 0.034, respectively). The rate of safety endpoint was the highest in patients in Group III (eGFR < 45 mL/min), and it was significantly higher than in patients in Groups I and II (p = 0.008 and p = 0.036, respectively). We did not observe antazoline-related adverse events in any of the studied groups of patients. This real-world registry analysis revealed a different influence of CKD on the effectiveness of individual drugs, and while propafenone and amiodarone maintained their AF termination efficacy, antazoline became significantly less effective in restoring sinus rhythm.

Relationship between vitaminD deficiency and success of cardioversion in patients with atrial fibrillation.

Inflammation plays an important role in the pathogenesis of atrial fibrillation (AF). VitaminD deficiency has been found to increase vulnerability to AF. The authors aimed to determine the relationship between vitaminD deficiency and cardioversion success in AF patients. The study included 200 persistent AF patients presenting for cardioversion. Serum vitaminD level was sampled on admission. The success of cardioversion was assessed and patients divided into two groups: successful or failed (groupI andII, respectively). VitaminD level was assessed and patients were divided into three groups: deficient, insufficient, and sufficient vitaminD level. Cardioversion was performed pharmacologically or electrically. Failure of cardioversion was defined as: (1)detection of AF rhythm in 12-lead ECG recording immediately after cardioversion or within 6‑month follow-up, or (2)ECG Holter monitoring of AF lasting > 30 s at 6‑month follow-up. There was ahighly statistically significant difference in baseline serum vitaminD level between groupI and groupII (P-value < 0.01). There were no statistically significant differences between the three groups in terms of vitaminD levels regarding age, gender, body mass index, smoking, and left atrial diameter. This study demonstrated that AF cardioversion failure was associated with vitaminD deficiency in patients without structural heart disease, while sufficient and insufficient vitaminD levels were associated with successful cardioversion. Therefore, vitaminD level assessment before cardioversion may help predict the success of cardioversion, and possible correction of deficient vitaminD levels may increase the chance of successful cardioversion.

Biomarkers associated with rhythm status after cardioversion in patients with atrial fibrillation

Biomarkers may help to improve our knowledge about the complex pathophysiology of atrial fibrillation (AF). In this study we sought to identify significant changes in biomarkers and clinical measures in patients with and without AF recurrence after electrical cardioversion. We measured 21 conventional and new biomarkers before and 30 days after electrical cardioversion and assessed the associations of changes in biomarker levels with rhythm status at follow-up. Significant between-group changes were observed for bone morphogenetic protein 10 (BMP10), N-terminal pro-B-type natriuretic peptide (NT-proBNP) and total bilirubin. Their respective changes were − 10.4%, − 62.0% and − 25.6% in patients with sinus rhythm, and 3.1%, 1.1% and − 9.4% in patients with recurrent AF, for a between-group difference of − 13.5% (95% confidence interval [CI] − 19.3% to − 7.6%; P < 0.001), − 63.1% (95% CI − 76.6% to − 49.6%; P < 0.001) and − 16.3% (95% CI − 27.9% to − 4.7%; P = 0.007). In multivariable models, the reductions of BMP10 and NT-proBNP were significantly associated with follow-up rhythm status (β coefficient per 1 − SD decrease, − 3.85; 95% CI − 6.34 to − 1.35; P = 0.003 for BMP10 and − 5.84; 95% CI − 10.22 to − 1.47; P = 0.009 for NT-proBNP. In conclusion, changes in BMP10 und NT-proBNP levels were independently associated with rhythm status after cardioversion, suggesting that these markers may be dependent on the actual heart rhythm.

Medicinal cardioversion in patients with paroxysmal form of atrial flutter at the prehospital stage

The work demonstrates the possibility of effective and safe medical cardioversion in patients with atrial flutter at the pre-hospital stage.

Nawrót arytmii i niepożądane zdarzenia sercowo-naczyniowe w ciągu 12 miesięcy po kardiowersji elektrycznej u pacjentów z migotaniem przedsionków stosujących doustne leki przeciwzakrzepowe

ENWEndNote BIBJabRef, Mendeley RISPapers, Reference Manager, RefWorks, Zotero AMA Turek Ł, Sadowski M, Janion-Sadowska A, Kurzawski J, Domagała S, Janion M. Recurrence of arrhythmia and adverse cardiovascular events within 12 months of electrical cardioversion in patients with atrial fibrillation receiving oral anticoagulation therapy. Medical Studies/Studia Medyczne. 2022;38(4):273-286. doi:10.5114/ms.2022.122383. APA Turek, Ł., Sadowski, M., Janion-Sadowska, A., Kurzawski, J., Domagała, S., & Janion, M. (2022). Recurrence of arrhythmia and adverse cardiovascular events within 12 months of electrical cardioversion in patients with atrial fibrillation receiving oral anticoagulation therapy. Medical Studies/Studia Medyczne, 38(4), 273-286. https://doi.org/10.5114/ms.2022.122383 Chicago Turek, Łukasz, Marcin Sadowski, Agnieszka Janion-Sadowska, Jacek Kurzawski, Szymon Domagała, and Marianna Janion. 2022. "Recurrence of arrhythmia and adverse cardiovascular events within 12 months of electrical cardioversion in patients with atrial fibrillation receiving oral anticoagulation therapy". Medical Studies/Studia Medyczne 38 (4): 273-286. doi:10.5114/ms.2022.122383. Harvard Turek, Ł., Sadowski, M., Janion-Sadowska, A., Kurzawski, J., Domagała, S., and Janion, M. (2022). Recurrence of arrhythmia and adverse cardiovascular events within 12 months of electrical cardioversion in patients with atrial fibrillation receiving oral anticoagulation therapy. Medical Studies/Studia Medyczne, 38(4), pp.273-286. https://doi.org/10.5114/ms.2022.122383 MLA Turek, Łukasz et al. "Recurrence of arrhythmia and adverse cardiovascular events within 12 months of electrical cardioversion in patients with atrial fibrillation receiving oral anticoagulation therapy." Medical Studies/Studia Medyczne, vol. 38, no. 4, 2022, pp. 273-286. doi:10.5114/ms.2022.122383. Vancouver Turek Ł, Sadowski M, Janion-Sadowska A, Kurzawski J, Domagała S, Janion M. Recurrence of arrhythmia and adverse cardiovascular events within 12 months of electrical cardioversion in patients with atrial fibrillation receiving oral anticoagulation therapy. Medical Studies/Studia Medyczne. 2022;38(4):273-286. doi:10.5114/ms.2022.122383.

Удержание синусового ритма после фармакологической кардиоверсии у пациентов с фибрилляцией предсердий и различной выраженностью COVID-пневмонии

Atrium fibrillation is one of the most frequent rhythm disruptions in patients with COVID infection. Restoration and maintenance of the sinus rhythm helps to improve hemodynamics and reduce the risks of cardiovascular complications. The article presents the data of restoring the sinus rhythm with a pharmacological cardioversion in patients after COVID infection with varied intensity of lung lesions and the duration of the sinus rhythm maintenance during 12 months of observation. The research results showed the connection between atrium fibrillation restoration with the intensity of lung lesions against the background of the past COVID infection.

Tissue Doppler Imaging of Left Atrial Appendage Predicts Successful Cardioversion in Patients with Atrial Fibrillation

Tissue Doppler Imaging of Left Atrial Appendage Predicts Successful Cardioversion in Patients with Atrial Fibrillation

Clinical experience of new antiarrhythmic drug refralon for pharmacological cardioversion in patients with atrial fibrillation after pulmonary vein cryoablation

We present two cases of successful pharmacological cardioversion using antiarrhythmic drug refralon in patients with persistent atrial fibrillation after pulmonary vein cryoablation and ineffective electrical cardioversion. These clinical cases represent the first experience of successful use of refralon in patients who underwent cryoablation.

Cardioversion in patients with newly diagnosed non-valvular atrial fibrillation: observational study using prospectively collected registry data

ObjectiveTo investigate the clinical outcomes of patients who underwent cardioversion compared with those who did not have cardioverson in a large dataset of patients with recent onset non-valvular atrial fibrillation.DesignObservational...

Adverse Events Associated With Electrical Cardioversion in Patients With Acute Atrial Fibrillation and Atrial Flutter

BackgroundWe sought to evaluate safety of electrical cardioversion (ECV) for patients with acute atrial fibrillation (AF) or atrial flutter (AFL) in the emergency department (ED). MethodsThis was an analysis of data from 4 multicentre AF/AFL studies conducted from 2008 to 2019 at 23 large EDs. We included adult patients who received attempts at ECV and who had presented acutely after symptom onset. Staff manually reviewed study and clinical records to abstract data. ResultsWe evaluated 1736 ECV cases with a mean age of 60.1 years and 67.1% male. The overall success of ECV was 90.2% (95% confidence interval 88.7%-91.6%), with 4.9% of patients admitted. ED physicians performed the ECV in 95.2% and provided sedation in 96.5%; 13.9% (12.3%-15.7%) of cases experienced important adverse events that required treatment, and 0.4% were classified as life threatening. Another 5.6% had adverse events that did not require treatment. Logistic regression found that the RAFF-3 study cohort (odds ratio [OR] 2.0), age ≥ 85 years (OR 2.1), coronary artery disease (OR 1.5), midazolam (OR 1.9), and fentanyl (OR 1.5) were associated with important adverse events. ConclusionsThis large evaluation of the safety of ECV for acute AF/AFL in the ED found that while serious adverse events were rare, there were a concerning number of events following sedation that required intervention. Physicians should be aware that older age, coronary artery disease, and fentanyl are associated with higher risks of important adverse events. This study provides more information for shared decision making discussions with patients when choosing between drug-shock and shock-only cardioversion strategies.

Racial and Sex Disparities in Anticoagulation After Electrical Cardioversion for Atrial Fibrillation and Flutter.

BackgroundAnticoagulation is indicated for 4 weeks after cardioversion in patients with atrial fibrillation/flutter. We sought to examine whether there is evidence of sex or racial disparity in anticoagulant prescription following cardioversion, and whether postcardioversion anticoagulation affects outcomes.Methods and ResultsWe identified a representative sample of Medicare patients who underwent elective electric cardioversion in an outpatient setting from 2015 to 2017. We identified patients who had an anticoagulant prescription for 3 months after the cardioversion date. Multivariable logistic regression was used to assess factors associated with a prescription of an anticoagulant after cardioversion. Cox regression analysis was used to test association of anticoagulation with a composite end point of 90‐day mortality, ischemic stroke, or arterial embolism. The final study cohort included 7860 patients. Overall, 5510 patients (70.1%) received any anticoagulation following cardioversion, while 2350 (29.9%) did not. Patients who did not receive anticoagulation were younger, with a lower burden of most comorbidities. Patients were less likely to receive anticoagulation if they had dementia or atrial flutter, while patients with valvular heart disease, obesity, heart failure, peripheral vascular or coronary disease, or hypertension were more likely to receive anticoagulation. Female sex (adjusted odds ratio, 0.84; 95% CI, 0.75–0.92; P<0.001), Black and Hispanic race (adjusted odds ratio, 0.50; 95% CI, 0.38–0.65; and odds ratio, 0.56; 95% CI, 0.41–0.75, respectively; P<0.001) were independently associated with lower probability of anticoagulant prescription. Postcardioversion anticoagulation was associated with lower risk of the composite end point (adjusted hazard ratio, 0.38; 95% CI, 0.27–0.52; P<0.001).ConclusionsRacial and sex disparities exist in anticoagulant prescription after outpatient elective cardioversion for atrial fibrillation.

Direct oral anticoagulants for electrical cardioversion

The article discusses the issues of anticoagulant preparation for elective electrical cardioversion in patients with persistent atrial fibrillation. Updated preparation regimens for electrical cardioversion are proposed, as well as the potential of using direct oral anticoagulants for this purpose is discussed.

Non-pharmacological interventions to improve the success of electrical cardioversion in patients with atrial fibrillation

Abstract Background: Electrical cardioversion (ECV) is a common management strategy for atrial fibrillation (AF). ECV contains multiple modifiable components, including pad size and placement, shock energy, and waveform phases. Guidance on optimal technique, however, is limited. A comprehensive review of interventions used to increase ECV success will guide ideal clinical practice and identify techniques that could be studied in future randomized controlled trials. Methods: This review will include RCTs randomized controlled trial and observational studies that compare acute cardioversion success between 2 or more non-pharmacological interventions in patients with AF undergoing ECV. We will search CENTRAL, MEDLINE and EMBASE from inception to present and will also include the grey literature as part of our search. We will assess the risk of bias for each study and summarize the extracted data in a narrative report with a table of findings included. Results: Based on a full search strategy developed for MEDLINE along with findings from the grey literature search, the non-pharmacological interventions are expected to include pad placement, shock energy, waveform phases, and manual pressure, among others. Conclusions: The objective of this scoping review is to identify and examine the evidence on non-pharmacological interventions to improve electrical cardioversion in patients with AF. Registered on Open Science Framework: https://osf.io/gdh27/

Implementation of a Procainamide-Based Cardioversion Strategy for the Management of Recent-Onset Atrial Fibrillation.

Atrial fibrillation/flutter (AF) remains the most common rhythm disturbance in adult patients presenting to emergency departments (EDs). Although pharmacologic cardioversion has been established as safe and effective in recent-onset AF, its use in U.S. EDs is uncommon. The purpose of this study was to assess the safety and efficacy of intravenous (IV) procainamide for pharmacologic cardioversion in patients presenting to the ED with AF of <48-hr duration. Patients presenting to the ED with recent-onset AF (<48 hr) undergoing a cardioversion strategy with IV procainamide from 2017 to 2019 were reviewed. Clinical outcomes assessed included rates of cardioversion, hospital admission, stroke, and return ED visits for arrhythmia or serious adverse events. A total of 64 patients received procainamide therapy-60.9% achieved cardioversion and 35.9% were admitted to the hospital. The mean dose was 1062.4 mg (12.1 mg/kg). No patients returned to the ED secondary to stroke and 9.4% experienced complications attributed to procainamide, the most common being hypotension. Within 30 days of therapy, 20.3% of patients returned to the ED secondary to arrhythmia recurrence. Patients experiencing cardioversion with procainamide were less likely to be admitted to the hospital (25.6% vs. 52.0%; p = 0.04) or receive a rate control agent (17.9% vs. 64.0%; p = 0.001). There was no significant difference in the rate of 30-day return between those who experienced pharmacologic cardioversion and those who did not (p = 0.220). The implementation of a procainamide-based acute cardioversion strategy for patients presenting to the ED with recent-onset AF resulted in a 60% cardioversion rate, which was associated with a significantly higher rate of discharge from the ED. Transient hypotension was the most common adverse event. Further investigation into ED-based protocols for management of recent-onset AF is necessary to better understand their safety and efficacy.

Outcomes of transesophageal echocardiogram-guided electrical cardioversion in patients with atrial fibrillation greater than 48 hours treated in the emergency department versus the cardiology ward: A retrospective comparison study.

The current emergency medicine literature on cardioversion for atrial fibrillation (AF) describes its performance on those who are hemodynamically unstable, present within 48hours of the onset of the arrhythmia, or are on long-term anticoagulants. For patients who are not anticoagulated and present with atrial fibrillation for more than 48hours, one option is to perform a transesophageal echocardiogram and then synchronized cardioversion in the absence of atrial clot. The objective of this study is to compare outcomes of patients presenting to the emergency department (ED) with atrial fibrillation (AF) of more than 48hours who underwent a transesophageal echocardiogram (TEE) and subsequent cardioversion in the ED versus the cardiology ward. This was a retrospective comparison study of patients who presented to the ED with AF for more than 48hours, underwent a transesophageal echocardiogram, and then were electrically cardioverted either in the emergency department or in the cardiology ward. Outcomes include: time to cardioversion, length of hospital stay, rate of successful cardioversion, and rate of complications. Electrical cardioversion was performed in the ED on 94 patients (62%) and the cardiology ward on 57 (38%). Over 90% of cardioversions were successful in both groups. Time to cardioversion was significantly less in the ED group versus the cardiology group (1.04±0.9days versus 3.81±1.9; P<.001). Similarly, the mean length of hospital stay was less for the ED group (1.6±1.6days versus 7.3±3.5; P<.001). Patients who present in atrial fibrillation for more than 48hours and then have a TEE undergo electrical cardioversion faster in the ED compared with the cardiology ward. This clinical pathway also results in a shorter length of hospital stay without having more side effects.

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.