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Atrial fibrillation/flutter (AF) is the most common dysrhythmia in patients with hypertrophic cardiomyopathy (HCM). Unexplained left ventricular hypertrophy and left ventricular outflow tract obstruction are integral components of HCM pathology which can cause increased left atrial pressure and atrial myopathy contributing to the substrate for AF. We aimed to determine the impact of AF on hospital readmissions in patients with HCM. We conducted a retrospective analysis using the 2015 to 2019 Nationwide Readmission Database to analyze the effect of AF on 30-day readmission and causes of 30-day readmission in patients with HCM. We also determined the hospital, patient, and procedure-specific independent predictors of readmission in patients with HCM and AF. Of 191,235 index HCM hospitalizations, 81,390 (42.6%) had a secondary diagnosis of AF. A total of 16.9% of patients with HCM and AF were readmitted within 30 days as compared with 14% of HCM patients without AF. The presence of AF was independently associated with a higher risk of all-cause 30-day readmission (hazard ratio [HR] 1.21, 95% confidence interval [CI] 1.17 to 1.25, p <0.001). The foremost etiology of 30-day readmission in HCM patients with AF was hypertensive heart and chronic kidney disease with heart failure, whereas the foremost etiology of 30-day readmission in HCM patients without AF was sepsis. Interventions aimed toward AF management (electrical cardioversion: adjusted HR 0.91, 95% CI 0.82 to 1.01. p = 0.074, AF ablation: HR 0.92, 95% CI 0.74 to 1.13, p = 0.409, Watchman procedure: HR 1.50, 95% CI 0.16 to 14.6, p = 0.725) during index admission did not significantly impact the 30-day readmission in HCM patients with AF. Myectomy during index hospitalization (adjusted HR 0.54, 95% CI 0.34 to 0.86, p = 0.010) was most strongly associated with a lower risk of 30-day readmission in HCM patients with AF. In conclusion, in patients hospitalized for HCM, presence of AF was associated with excess risk of 30-day all-cause readmission. Interventions aimed toward HCM management, that is, myectomy rather than interventions aimed toward AF management predicted lower readmission rate in this patient population., Competing Interests: Declaration of competing interest Dr. Fudim has received support from National Heart, Lung, and Blood Institute grant K23HL151744, American Heart Association grant 20IPA35310955, the Mario Family Award, the Duke Chair's Award, the Translating Duke Health Award, Bayer, and BTG Specialty Pharmaceuticals; and has received consulting fees from AstraZeneca, Axon Therapies, CVRx, Daxor, Edwards Lifesciences, Galvani, and NXT Biomedical. Dr. Krasuski is serving as a consultant to Actelion/Janssen Pharmaceuticals, Bayer Pharmaceuticals, Gore Medical, and Medtronic. He receives research funding from the Adult Congenital Heart Association and Actelion. Dr. Khan has taken fees from Bayer. The remaining authors have no competing interests to declare., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Successful synchronized direct current cardioversion (DCCV) requires adequate current delivery to the heart. However, adequate current for successful DCCV has not yet been established. Transmyocardial current depends on 2 factors: input energy and transthoracic impedance (TTI). Although factors affecting TTI have been studied in animal models, factors affecting TTI in humans have not been well established. Herein, we explored the potential factors that affect TTI in humans. A retrospective review of patients who underwent 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, was 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% women) were included in the analysis; 143 of the patients (65%) underwent DCCV for atrial fibrillation and 77 (35%) underwent DCCV for atrial flutter. The mean impedance in our population was 73 ± 18 Ω. In a regression model with high impedance defined as the upper quartile of our cohort, body mass index (BMI), female sex, obstructive sleep apnea, and chronic kidney disease (all p values <0.05) were significantly associated with high impedance. According to a receiver operating characteristic analysis, BMI has a high predictive value for high impedance, with an area under the curve 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 determine the appropriate initial shock energy in patients who underwent DCCV for atrial fibrillation and flutter., Competing Interests: Declaration of competing interest Dr. Yarmohammadi had lectures/heart dissections supported by Zoll. Dr. Wan has been a consultant for Boston Scientific, Medtronic, Abbott, Sanofi, and Cardiologs. The remaining authors have no competing interests to declare., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: High-sensitivity cardiac troponin (hs-cTnT) is often increased in patients with atrial fibrillation/flutter, portending a poor prognosis. The etiologies for these increases have not been systematically investigated. Our aim was to define prevalence/significance of structural cardiac abnormalities in patients with atrial fibrillation/flutter and high-sensitivity cardiac troponin T (hs-cTnT) increases., Methods: This is a retrospective observational cohort study of patients with atrial fibrillation/flutter diagnosis with hs-cTnT measurements, echocardiograms, and coronary angiograms. Myocardial injury was defined as hs-cTnT >10 ng/L for women and >15 ng/L for men. Cases with myocardial injury were adjudicated according to the Fourth Universal Definition of Myocardial Infarction., Results: Patients with definite causes for increased hs-cTnT (n = 875) were tabulated but not evaluated further; common diagnoses were type 1 myocardial infarction, critical illness, and known heart failure. Of the remaining 401, increased hs-cTnT was present in 336 (84%) patients. Of those, 78% had nonischemic myocardial injury, the remaining (n = 75, 22%) had type 2 myocardial infarction. Patients with elevated hs-cTnT had greater left ventricular mass index, left ventricular filling pressures, and right ventricular systolic pressure. They more frequently had significant coronary artery disease (47% vs 31%, P = .016), especially in type 2 myocardial infarction. With logistic regression, age, sex (F), diabetes, left ventricular mass index, e' medial velocity, and right ventricular systolic pressure were independent determinants of myocardial injury. One-year mortality was higher in patients with myocardial injury., Conclusions: Structural heart abnormalities are common in patients with atrial fibrillation/flutter and increased hs-cTnT. Causes of myocardial injury should be elucidated in each patient to craft appropriate therapies., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Atrial fibrillation (AF) and flutter (AFL) frequently complicate transthyretin cardiac amyloidosis (ATTR-CM). Management poses challenges as rate control drugs are poorly tolerated and data addressing tolerability and efficacy of rhythm control is limited. We report outcomes of AF/AFL in ATTR-CM in a single center observational study of patients seen at our Amyloidosis Center with wild-type or hereditary ATTR-CM diagnosed between 2005-2019 including 84 patients (average age 74 ± 10 years, 94% male) with 27.6 ± 22.8 months follow-up. AF/AFL occurred in 61 patients (73%). Rapid ventricular response was common as was attempted rate control. However, discontinuation of rate control drugs was frequent (80%), often for adverse effects. Rhythm control was attempted in 64%, usually with cardioversion (DCCV) or ablation. Post-DCCV recurrence was common (91%) and time to recurrence was similar with or without anti-arrhythmic drugs (5.8 months (IQR 1.9-12.5) vs 6.2 months (IQR 1.9-12.5) p = 0.83). Ablation was performed in 23% with AFL (all for typical AFL) with 14% recurrence after mean of 60.9 months. Ablation for AF was performed in 12% with 86% recurrence after median of 6.2 months (IQR 5.6-12.3). Most patients (62%) with rhythm control had subjective improvement (≥1 NYHA class or resolved palpitations). In conclusion, AF/AFL was common in our cohort. Rate control was poorly tolerated and often abandoned. Rhythm control led to symptomatic improvement in a majority of cases, but durable success was limited. DCCV was modestly successful and not significantly improved with anti-arrhythmics. Ablation was successful with typical AFL but had limited success in AF., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Atrial fibrillation-flutter (AF) has been described in 10% to 24% of patients after heart transplant (HT). Data on AF hospitalizations after HT are limited to single-center experiences. To bridge this gap, we performed an analysis of admissions for AF in HT patients from the National Inpatient Sample (NIS) years 2000 to 2014. All hospitalizations with a primary diagnosis of 427.31 or 427.32 and V42.1 were used to identify hospitalizations with AF and previous HT respectively. Among a total of 211,961 HT related hospitalizations, 1,304 (0.62%) (955 males, 349 females, mean age 59 years, median CHA 2 DS 2 Vasc score 2 [Interquartile range 1 to 3]) were admitted with a primary diagnosis AF. Most hospitalizations were nonelective (80.17%). In-hospital mortality was 2.3% and the mean length of stay (LOS) was 3.7 days. Among those patients who were discharged from hospital, 85 % were discharged to home with self-care. Most commonly reported secondary diagnoses included hypertension (57.9%), diabetes (33%), renal failure (31.3%), and congestive heart failure (22%). The event rates for ischemic stroke and gastrointestinal bleeding in the same admission with the AF hospitalization were low (1.2% and 1.2% respectively). Cardioversion was performed in 37% and ablation in 11.2% of admissions. The adjusted median cost of hospitalization was $6478.7 (IQR $3561.8 to $12352.3) and did not change significantly during the study period. AF is a relatively infrequent cause of hospitalization among HT recipients. The number of hospitalizations, ablations, cardioversions, disposition, LOS, and cost of hospitalization for AF remained stable during the study period., (Copyright © 2019 Elsevier Inc. All rights reserved.)

The efficacy of novel oral anticoagulants (NOACs) in severely obese patients is uncertain as volume of distribution is related to weight, and few such patients were enrolled in the pivotal trials. As the month after direct-current cardioversion (DCCV) for atrial fibrillation and atrial flutter is a high-risk period for stroke, we sought to evaluate the safety of performing DCCV in obese patients on NOAC. All patients who underwent DCCV after ≥3 weeks of NOAC or therapeutic warfarin treatment without a previous transesophageal echocardiogram over a 3-year period at a single center were included. Obesity groups were defined as normal (body mass index [BMI] < 25), overweight (BMI 25 to <30), class 1 obesity (BMI 30 to <35), class 2 obesity (BMI 35 to <40), and class 3 or severe obesity (BMI ≥ 40). The primary end point was stroke at 30days. Of 761 patients, 73 were severely obese, 78 class 2 obese, 197 class 1 obese, 254 overweight, and 159 in the normal weight group. Average age 66.4 ± 10.3years and 32.5% women. Mean CHA 2 DS 2 -VASc score was 2.6 ± 1.6, and 78.9% were on NOACs with no differences in groups. There were no strokes in the severely obese group, and 1 each in class 2 obesity and normal weight (p = 0.3). In conclusion, there was a low rate of stroke in all weight classes after DCCV in patients taking NOACs and warfarin. NOAC use in severely obese patients who underwent DCCV appears safe even in the absence of transesophageal echocardiogram., (Copyright © 2018. Published by Elsevier Inc.)

External transthoracic direct current (DC) cardioversion is a commonly used method of terminating cardiac arrhythmias. Previous research has shown that DC cardioversion resulted in myocardial injury as evidenced by increased levels of cardiac troponin, even though only minimally. Many of these studies were based on the outdated monophasic defibrillators and older, less sensitive troponin assays. This study aimed to assess the effect of external transthoracic DC cardioversion on myocardial injury as measured by the change in the new high-sensitivity cardiac troponin T (hs-cTnT) using the more modern biphasic defibrillators. Patients who were admitted for elective DC cardioversion for atrial fibrillation or atrial flutter were recruited. Hs-cTnT levels were taken before cardioversion and at 6 hours after cardioversion. A total of 120 cardioversions were performed. Median (twenty-fifth to seventy-fifth interquartile range) cumulative energy was 161 J (155 to 532 J). A total of 49 (41%) patients received a cumulative energy of 300 J or higher. The median hs-cTnT level before cardioversion was 7 ng/L (4 to 11 ng/L) and that after cardioversion was 7 ng/L (4 to 10 ng/L). A Wilcoxon signed-rank test showed no significant difference between pre- and post-cardioversion hs-cTnT levels (Z = -0.940, p = 0.347). In conclusion, external DC cardioversion did not result in myocardial injury within the first 6 hours as measured by high-sensitivity troponin T. Patients who are cardioverted and are found to have a significant increase in cardiac troponin after cardioversion should be assessed for causes of myocardial injury and not assumed to have myocardial injury due to the cardioversion itself., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Few data exist on direct current cardioversion (DCCV) in adult patients with congenital heart disease (CHD). This is a retrospective case-control study of 279 adults with CHD and 279 adults without CHD (control group) who had elective DCCV for atrial arrhythmias at Mayo Clinic, 2001 to 2013. Control patients were matched by gender and arrhythmia type. The objective was to compare DCCV procedural failure (failure to terminate the presenting arrhythmia) and arrhythmia recurrence (AR). In the CHD group (mean age 55 ± 20 years; men 166 [59%]), the most common diagnosis was Fontan palliation (61; 22%). Transesophageal echocardiography was performed before DCCV in 216 patients (77%); 162 (58%) had atrial flutter, and 117 (42%) had atrial fibrillation. Procedural failure and AR between the case and the control groups were more common in the CHD group (14% vs 7%, p = 0.01) and (83% vs 66% at 60 months, p = 0.001) respectively. There were no deaths or thromboembolic complications. The multivariable risk factors for procedural failure were Fontan palliation and spontaneous echocardiographic contrast; the risk factors for AR were Fontan palliation and atrial fibrillation. When patients with Fontan palliation were excluded from the analysis, the outcome of DCCV (failure and recurrence rates) was similar for the CHD and non-CHD groups despite the age difference between the cohorts. In conclusion, the present study showed that DCCV outcomes were similar for CHD and non-CHD patients, with the exception of patients with Fontan palliation., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Competing Interests: None of the authors have any conflicts of interest to report in association with this topic.

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., (Copyright © 2014 Elsevier Inc. All rights reserved.)

The responsibility of managing atrial fibrillation (AF) and atrial flutter (AFL) falls predominantly on the Medicare system. Patients with AF or AFL often have a range of cardiovascular (CV) co-morbidities and are frequently hospitalized for AF and other CV causes. The present retrospective cohort study used medical claims data to evaluate the rates of hospitalization and inpatient mortality in elderly (aged ≥65 years) patients with AF or AFL with Medicare supplemental insurance. The data were extracted from the United States Thomson Reuters MarketScan Medicare Supplemental and Coordination of Benefits Database (January 2004 to December 2007). Patients aged ≥65 years with ≥1 inpatient or ≥2 outpatient nondiagnostic claims for AF or AFL and ≥12 months of continuous enrollment before their index AF or AFL diagnoses were identified. The frequencies of hospitalization and inpatient death were evaluated over the postindex study period (mean 24.3 months). Of an eligible study population of 55,774 patients with AF or AFL (mean age 77.9 years, 52.2% men), 28,939 patients (51.9%) were hospitalized (all causes) with nonfatal outcomes, 12,652 (22.7%) were rehospitalized, and 1,592 (2.9%) died in the hospital. Higher proportions of patients were hospitalized for non-CV than for CV causes (35.6% vs 27.2%). For CV hospitalizations culminating in inpatient death (n = 516), the most common admission diagnoses were major bleeding, stroke or transient ischemic attack, and congestive heart failure. In conclusion, elderly patients with AF or AFL undergo frequent hospitalization for CV and non-CV causes. Measures that lower inpatient admission rates, particularly readmission rates, may reduce the increasing cost of treating patients with AF or AFL with Medicare supplemental insurance., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Information on atrial arrhythmia associated with right ventricular cardiomyopathy/dysplasia (ARVC/D) is limited. In 36 patients with task force criteria for ARVC/D and history of ventricular tachycardia (VT), we confirmed the incidence and type of atrial arrhythmia, onset related to referral for VT ablation, fastest documented ventricular rate, management, and clinical and hemodynamic factors associated with their development. Thirty-six patients (28 men) had a mean age of 47 years (range 17 to 80) and mean follow-up of 56 +/- 44 months. Thirty-five patients (97%) had implantable cardioverter-defibrillator (ICD) devices, 15 with atrial leads. Fifteen of 36 patients (42%) had documented atrial arrhythmias, with atrial flutter (aFL) in 11, atrial fibrillation (AF) in 11 patients, and aFL and AF in 7 patients. Maximum heart rate noted with atrial arrhythmia was 62 to 150 beats/min. In 9 patients, initial atrial arrhythmia preceded or was concurrent with presentation for VT ablation. In the remaining 6 patients, atrial arrhythmia (symptomatic in 4 patients) followed VT presentation. Three of these patients received ICD shock therapy for atrial arrhythmias. Seven of 11 patients with recurrent aFL required aFL ablation, 1 patient underwent His-bundle ablation for AF with rapid rate, and 8 patients required long-term drug therapy for AF control. Atrial arrhythmias were more common in patients with RV enlargement and moderate/severe tricuspid regurgitation. In conclusion, in patients with ARVC/D and VT, atrial arrhythmias are common, frequently necessitate ablative or pharmacologic treatment, and are more common in patients with moderate/severe tricuspid regurgitation and markedly enlarged right ventricle., (2010 Elsevier Inc. All rights reserved.)

Atrial fibrillation (AF) and atrial flutter (AFL) after heart transplantation (HT) has been associated with increased mortality. Diverse incidence rates have been reported to date, with no clear classification according to the time of onset of such arrhythmias. We determined the incidence of AF/AFL using the time of onset after HT and analyzed the associated risk factors and outcomes. We performed a retrospective study of 228 HT recipients (March 1996 to July 2007), including donor and recipient demographics, gender mismatch, ischemia time, surgical anastomosis, time of onset of AF/AFL, acute cellular rejection, left ventricular systolic function, and all-cause mortality. The mean age of the donors (81% men) was 30 +/- 12 years and of the recipients (78% men) was 53 +/- 11 years. AF/AFL occurred in 45 patients (20%): 24 (11%) in the first 30 days, 10 (4%) within the 31 days to 1 year, and 11 (5%) after 1 year. When the patients with AF/AFL were compared to those with sinus rhythm, the significant difference was the older mean age of the donors (p = 0.001) and the recipients (p = 0.02). The all-cause mortality rate was 43% for those with AF/AFL compared to 23% for those with sinus rhythm (hazard ratio 2.45; 95% confidence interval 1.2 to 4.8), mostly driven by the greater mortality in the later-onset AF/AFL group (>30 days after HT). In conclusion, AF and AFL have an incidence of 20% after HT and are associated with increased overall mortality compared to that in patients in sinus rhythm. AF/AFL is more common within the first 30 days of HT, with an overall incidence of 20%. Older donor and recipient age is a risk factor associated with AF/AFL., (Published by Elsevier Inc.)

External cardioversion is an established and very important tool to terminate symptomatic atrial flutter. The superiority of the biphasic waveform has been demonstrated for atrial flutter, but whether electrode position affects the efficacy of cardioversion in this population is not known. The aim of this trial was to evaluate whether anterior-lateral (A-L) compared with anterior-posterior (A-P) electrode position improves cardioversion results. Of 130 screened patients, 96 (72 men, mean age 62 +/- 12 years) were included and randomly assigned to a cardioversion protocol with either A-L or A-P electrode position. In each group, 48 patients received sequential biphasic waveform shocks using a step-up protocol consisting of 50, 75, 100, 150, or 200 J. The mean energy (65 +/- 13 J for A-L vs 77 +/- 13 J for A-P, p = 0.001) and mean number of shocks (1.48 +/- 1.01 for A-L vs 1.96 +/- 1.00 for A-P, p = 0.001) required for successful cardioversion were significantly lower in the A-L group. The efficacy of the first shock with 50 J in the A-L electrode position (35 of 48 patients [73%]) was also highly significantly greater than the first shock with 50 J in the A-P electrode position (18 of 48 patients [36%]) (p = 0.001). In conclusion, the A-L electrode position increases efficacy and requires fewer energy and shocks in external electrical cardioversion of common atrial flutter. Therefore, A-L electrode positioning should be recommended for the external cardioversion of common atrial flutter.

We aimed to determine whether smoking status affects the recurrence of atrial fibrillation or atrial flutter in patients after cardioversion. The clinical data of patients undergoing cardioversion for atrial flutter from January 1, 2000 to December 31, 2005 were prospectively collected. Arrhythmia recurrences were detected by retrospective review of comprehensive medical records and were determined using electrocardiography. The smoking history was prospectively collected through a standardized clinical form and subsequently categorized as lifetime nonsmoker, exsmoker, or current smoker. Univariate and multivariate associations with end points for clinical and lifestyle variables were assessed with Cox proportional hazards models. Women who were current smokers at cardioversion had a greater risk of atrial arrhythmia recurrence than did nonsmokers (hazard ratio 1.71, 95% confidence interval 1.10 to 2.67, p = 0.02). The increased risk of arrhythmia recurrence in female smokers was not seen in male smokers. Compared to lifetime nonsmokers, the mortality hazard ratio among men was 1.18 (95% confidence interval 0.88 to 1.58; p = 0.28) in exsmokers and 1.93 (95% confidence interval 1.20 to 3.11; p = 0.007) in current smokers. The risk of death after cardioversion was not increased in women. In conclusion, smoking is an independent predictor of atrial arrhythmia recurrence after cardioversion in women; however, an increased mortality risk, but not arrhythmia recurrence risk, was seen in men.

Sleep apnea (SA) is more prevalent in patients with atrial fibrillation (AF), but the impact of cardioversion on disordered breathing is unknown. Thus, we investigated the influence of restoring sinus rhythm in patients with AF and atrial flutter (AFlut) on SA. The 16 patients (mean age 63.1 +/- 11.2) with AF (n = 6) or AFlut (n = 10) and SA (apnea-hypopnea index >10) received cardioversion or ablation of cavotricuspid isthmus. We compared the severity of SA by sleep polygraphy under AF/Aflut with the first night after restoring sinus rhythm and after 4 weeks. Apnea-hypopnea index before and immediately after restoring sinus rhythm was similar (31.7 +/- 13.2 vs 30.1 +/- 15.7, p = NS) despite a significantly reduced heart rate (86.7 +/- 26.5 vs 67.8 +/- 11.9 beats/min, p <0.02). After 4 weeks, apnea-hypopnea index remained unchanged (38.1 +/- 18.1, p = NS) although heart rate was further reduced (61.8 +/- 8.8 beats/min, p <0.003). In our study, SA could not be improved by cardioversion of AF/AFlut. Therefore, although it is well known that SA leads to AF, eliminating AF does not cure or improve SA. In conclusion, our study shows that AF should be regarded more as an innocent bystander than a causative or aggravating condition in SA.

Purpose: To evaluate trend in mortality in stroke associated with atrial fibrillation, we examined mortality trend after stroke with atrial fibrillation by calendar year period (1980-1984, 1985-1989, 1990-1994, 1995-1999, and 2000-2002). We estimated trends separately for each sex in unadjusted analyses. We also adjusted for age, comorbid conditions, and general trend in mortality in the background population., Methods: We identified all individuals, aged 40-89 years, with an incident diagnosis of stroke of any nature (ischemic or hemorrhagic) and no history of heart valve disease and a previous or concomitant diagnosis of atrial fibrillation or flutter in the Danish National Registry of Patients. Subjects were followed in the Danish Civil Registration System for emigration and vital status. We used multivariate Cox proportional hazards regression analysis to estimate trend in mortality., Results: Incident stroke with a previous or concomitant diagnosis of nonvalvular atrial fibrillation or flutter was diagnosed in 24,470 subjects (11,554 men and 12,916 women). During 34,405 years of observation, 9237 men died, and during 35,381 years of observation, 10,827 women died. The hazard ratio for mortality after stroke in the last 3-year period compared with the first 5-year period was .65 (95% confidence interval [CI], .61-.71) in men and .69 (95% CI, .64-.74) in women., Conclusions: We observed a substantially better survival in men and women after stroke associated with atrial fibrillation or flutter in Denmark during the years 1980 to 2002. However, we could not control for changes in admission practice, diagnostic performance, or treatment.

Background: In patients undergoing transesophageal echocardiography-guided cardioversion, we evaluated the use and safety of an expedited in-hospital anticoagulation regimen that incorporates shorter-than-standard durations of precardioversion intravenous unfractionated heparin and postcardioversion bridging therapy with a low-molecular-weight heparin., Methods: Adult patients who underwent successful transesophageal echocardiography-guided cardioversion for atrial fibrillation or atrial flutter between May 2000 and August 2003 were classified into 2 groups by duration of intravenous unfractionated heparin therapy (<24 h or > or =24 h) before transesophageal echocardiography and cardioversion. Safety end points evaluated included all-cause death, stroke or other thromboembolic events, and major bleeding complications within 1 month after successful cardioversion., Results: The study population of 386 patients included 199 (52%) who received expedited intravenous unfractionated heparin (<24 h; minimum duration, <4 h) and 193 patients (50%) who were discharged on low-molecular-weight heparin therapy. The adverse event rates at 1-month follow-up were not significantly different between the 2 unfractionated heparin patient groups, and the rate of stroke among patients dismissed on low-molecular-weight heparin was less than 1%. No adverse events occurred among patients who received intravenous unfractionated heparin for less than 12 hours and who were dismissed on low-molecular-weight heparin bridging therapy., Conclusions: The use of an expedited heparin anticoagulation regimen in patients with atrial fibrillation or atrial flutter undergoing transesophageal echocardiography-guided cardioversion appears to be safe. Cardioversion can be performed as early as a few hours after initiation of intravenous unfractionated heparin, and bridging therapy with a low-molecular-weight heparin can be used after cardioversion until the international normalized ratio is therapeutic.

In 79 consecutive patients (51 men and 28 women) with paroxysmal (n = 54) or persistent atrial fibrillation (AF) (n = 25) and typical, isthmus-dependent atrial flutter (AFl), pulmonary vein (PV) isolation and anatomically guided linear ablation of the right atrial isthmus was performed during the same procedure. After 208 +/- 331 days of follow-up, 42% remained free of AF and AFl, and a symptomatic lessening was reported by 77%. Paroxysmal AF (beta = 1.682, p = 0.008) and ablation of 3 or 4 PVs (beta = 1.830, p = 0.013) were independent predictors for arrhythmia-free survival. Combined catheter ablation of PVs and the right atrial isthmus for the treatment of patients with mixed AF and AFl is moderately effective in preventing early arrhythmia recurrence but leads to clinical improvement in most patients., (Copyright 2004 Excerpta Medica, Inc.)

External cardioversion using the monophasic damped sine (MDS) waveform is successful 70% to 94% of the time when using up to 360 J. The rectilinear biphasic (RLB) defibrillator has been shown to be superior in efficacy to the MDS waveform in atrial cardioversion in a small randomized study. This larger, retrospective study compares the results of the RLB waveform with those of the MDS waveform for cardioversion of atrial fibrillation (AF) and atrial flutter in a large cohort of patients. We performed 1,877 external cardioversion procedures in 1,361 patients for AF and atrial flutter by using the RLB defibrillator. We compared these results with those of the MDS defibrillator in 2,025 patients who underwent 2,818 cardioversion procedures. The overall success rates for the RLB defibrillator were 99.1% for AF and 99.2% for atrial flutter, and the corresponding success rates for the MDS defibrillator were 92.4% and 99.8% (p <0.001; RLB superior for AF). The median overall successful energy level for the MDS waveform was 200 J, whereas the corresponding RLB energy level was 100 J. Multivariate analyses demonstrated that underlying clinical conditions or use of antiarrhythmic drugs does not significantly affect overall success rates. Our results from >4,000 procedures confirmed and extended those of the previous report by showing a very high success rate for cardioversion of AF and atrial flutter using the RLB waveform. The MDS waveform was equally effective for atrial flutter but significantly less effective in terminating AF.

Atrial flutter (AFl) recurrence after initial in-patient presentation, cardioversion, and drug treatment is almost universal, often leading to rehospitalization and risk of serious clinical consequences. Radiofrequency ablation of AFl, which has an excellent safety record, should be evaluated as a first-line approach for most patients with AFl.

Patients with congenital heart disease are vulnerable to atrial tachyarrhythmias, especially after atrial surgeries. We evaluated the efficacy of atrial arrhythmia detection and antitachycardia pacing (ATP) using the Medtronic AT500 pacemaker in 28 patients with congenital heart disease (age 30 +/- 18 years). Of 15 patients with atrial arrhythmias, 14 had atrial tachycardia events that were appropriately detected. ATP was enabled for 167 treatable episodes, successfully converting 90 (54%). Rhythms classified as ventricular tachycardia were detected 127 times, yet most were actually atrial or sinus tachycardia with 1:1 atrioventricular conduction. Atrial tachycardias in congenital heart disease are amenable to ATP algorithms in the AT500 pacemaker.

The purpose of this study was to explore the mechanisms of conversion from atypical atrial flutter (AFL) to atrial fibrillation (AF), and the long-term results of cavotricuspid isthmus ablation in these patients. We retrospectively reviewed the records of 221 patients with typical AFL referred to our hospital for ablation. A total of 25 patients had atypical AFL, and cavotricuspid isthmus ablation was performed in 23 with isthmus-dependent atypical AFL, as well as in 180 patients with typical counterclockwise and/or clockwise AFL. In all, 13 spontaneous transitions from atypical AFL to AF were documented in 11 of 17 patients. Before AF, a pattern of lower loop reentry was observed in 11 of 13 patients (85%) and upper loop reentry in 3 (1 had both). Multiple early breaks along the tricuspid annulus during AFL were noted in 6 of 13 patients (46%). Among the 13 transitions, discrete atrial premature complexes before AF were found in 5 patients with lower loop reentry and in 1 with upper loop reentry (46%). In the remaining patients, a more rapid atrial rhythm was involved in the development of AF with a pulmonary venous focus in 2. In some cases, additional "breaks" in the functional line of block occurred before the development of AF. There was a significant increased incidence of AF (68%) in those with atypical AFL compared with those with typical AFL (38%) (p = 0.004). After a mean follow-up of 28 +/- 9 months for the atypical group and 18 +/- 11 months for the typical group, the AF recurrence rate was similar (57% vs 48%, p = 0.4). Discrete atrial premature complexes or atrial tachycardia may initiate AF either directly or by producing further breaks in lines of functional block. Bidirectional cavotricuspid isthmus block is associated with cure or control of AF in approximately 50% of patients with AFL.

We compared transesophageal and phased-array intracardiac echocardiography (TEE/ICE) for the 2-dimensional and spectral Doppler assessment of left atrial (LA) mechanical function. TEE is commonly used to assess LA body and LA appendage mechanical function in patients who are undergoing radiofrequency ablation of typical atrial flutter. Fifteen patients underwent TEE and ICE imaging before and after ablation of typical atrial flutter. The following parameters were measured: (1) LA appendage emptying velocity and fractional area change, (2) severity of LA spontaneous echo contrast (graded 0 to 4), (3) maximal inflow velocity of the left and right upper pulmonary veins, and (5) maximal mitral valve E- and A-wave inflow velocities in sinus rhythm. Diagnostic quality imaging was achieved in all patients with TEE and ICE. Comparing TEE and ICE, the following absolute values and linear correlation coefficient (R) were obtained: preablation LA appendage emptying velocity: 0.45 +/- 0.21 versus 0.44 +/- 0.21 m/s (r = 0.95, p = <0.001); postablation LA appendage velocity: 0.33 +/- 0.24 versus 0.34 +/- 0.24 m/s (r = 0.97, p <0.001); LA appendage fractional area change: 35.3 +/- 13.7 versus 35.9 +/- 17.1% (r = 0.81, p <0.001); left upper/right upper pulmonary vein inflow velocity: 0.50 +/- 0.17/0.49 +/- 0.18 versus 0.51 +/- 0.17/0.47 +/- 0.20 m/s (r = 0.93/0.90, p <0.001); mitral valve E/A wave: 0.66 +/- 0.14/0.31 +/- 0.14 versus 0.69 +/- 0.17/0.35 +/- 0.23 (r = 0.84/0.97, p <0.002); LA spontaneous echo contrast (pre- and postablation): 1.1 +/- 1.2/1.3 +/- 1.2 versus 1.2 +/- 1.3/1.4 +/- 1.3 (r = 0.92/0.90, p <0.001). No patients were identified with LA appendage thrombus. Thus, TEE and phased-array ICE provided equivalent imaging data with high statistical correlation. ICE may be an imaging alternative to TEE in the evaluation of a "stunned" left atrium.

Purpose: To determine the incidence of thromboembolic complications after cardioversion in patients with atrial flutter., Subjects and Methods: We reviewed 615 electrical cardioversions performed electively in 493 patients with atrial flutter. Embolic complications were evaluated during the 30 days after cardioversion. Follow-up data were obtained by follow-up visits and by contacting the treating physician., Results: Anticoagulants had been administered in 415 cardioversions (67%). Cardioversion was successful in 570 procedures (93%). Three embolic events (in 3 patients) occurred in the 30 days after 550 successful cardioversions with completed follow-up (0.6% of successful procedures; 95% confidence interval, 0.1% to 1.6%). Two of the 3 patients had not been anticoagulated, whereas the third patient had subtherapeutic oral anticoagulation. No embolic event occurred in procedures performed with adequate anticoagulation. The incidence of embolism in patients regardless of subtherapeutic anticoagulation was 1% (3 of 303 successful cardioversions)., Conclusions: We observed a low (0.6%) incidence of postcardioversion thromboembolic complications in patients with atrial flutter. Embolic events did not occur in patients with adequate anticoagulation.

An abrupt decrease in the pacing rate in patients with dual-chamber pacemakers tracking atrial tachyarrhythmias carries a high risk of malignant ventricular arrhythmia. The pacing rate should be reduced by multistep programming over several days.

The pure class III agent dofetilide was evaluated to determine its effect on atrial function after cardioversion of atrial fibrillation or flutter. Compared with placebo, dofetilide-treated patients had evidence of better atrial function after cardioversion, indicating that this agent has a positive atrial inotropic effect during the period of postcardioversion atrial stunning.

The clinical effectiveness and cost to convert recent-onset atrial fibrillation or flutter to sinus after 3 to 4 weeks of anticoagulation with intravenous ibutilide was compared with direct-current cardioversion. The low success rate with ibutilide made direct-current cardioversion the more clinical and cost-effective method to restore sinus rhythm.

Conversion of atrial flutter and atrial fibrillation (AF) can be achieved by either pharmacologic or direct-current (DC) electrical cardioversion. DC electrical cardioversion is more effective and restores sinus rhythm instantaneously; however, general anesthesia is necessary, which can cause severe complications. On the other hand, pharmacologic cardioversion is less effective. First, time to conversion is unpredictable and may be relatively long, especially with oral drug therapy. Also, the rate of conversion is lower and depends on duration of AF. In addition, safety is an important issue. Adverse drug reactions include bradycardia, paradoxical tachycardia due to enhanced atrioventricular conduction, ventricular proarrhythmia, and acute heart failure. In paroxysmal AF, drug therapy is usually aimed at an acute conversion. Class IA and IC drugs are more efficacious than the class III drugs sotalol, amiodarone, and ibutilide. By contrast, class III drugs are more effective for the conversion of atrial flutter. Acute conversion out-of-hospital ("pill in the pocket approach") should be done only if the drug used appeared effective and safe after a few in-hospital trials. In persistent AF, DC conversion is preferred because drugs are particularly ineffective if the arrhythmia has lasted >24-48 hours. The latter probably relates to electrical and anatomical remodeling of the atria during ongoing atrial fibrillation and flutter. Nevertheless, a wait-and-see approach using, for example, oral amiodarone may be adopted with late DC conversion if the drug fails to convert persistent AF. However, the consequences of remodeling seem to dictate an early conversion. In this respect, echocardiography-guided DC cardioversion may become increasingly important in AF. It will prevent treatment resistance and potentially reduces embolic complications. In a hybrid approach, antiarrhythmic drugs may be used to enhance DC conversion and prevent (sub)acute recurrences of AF. However, it may increase the defibrillation threshold, especially if class IC drugs are used. New treatment options such as automatic defibrillation (implantable atrioverter) are still investigational.

Pooled data from 32 studies were reviewed to assess the timing of thrombolic complications after cardioversion of atrial fibrillation or flutter. We found that 98% of embolic episodes occurred within 10 days of cardioversion.

With use of transesophageal echocardiography, the short-term effects of transthoracic electrical cardioversion of atrial flutter (AFI) on atrial mechanical function and spontaneous echo contrast were determined. Thirty patients who had AFI for a mean of 6.4 +/- 12.2 months underwent transthoracic cardioversion. A transesophageal echocardiogram was recorded immediately before cardioversion, and left atrial appendage emptying velocity and spontaneous contrast were assessed serially at 1, 3, and 5 minutes after cardioversion in 28 patients, and also at 8, 10, and 15 minutes after cardioversion in a subgroup of 13 patients. Cardioversion was deferred in 2 patients (7%) because a thrombus was found in the left atrial appendage. Before cardioversion, spontaneous contrast was present in the left atrium in 7 of 28 patients (25%) who underwent cardioversion. The mean left atrial appendage emptying velocity of 54 +/- 22 cm/s before cardioversion fell by 26% to 40 +/- 25 cm/s at 1 minute after restoration of sinus rhythm (p <0.01). There were no significant changes in the mean left atrial appendage-emptying velocity between 1 and 15 minutes after cardioversion. Within 5 minutes after conversion to sinus rhythm, left atrial spontaneous echo contrast developed de novo or worsened in 12 of the 28 patients (43%). In conclusion, the results of this study demonstrate that persistent AFI may be associated with left atrial thrombi before cardioversion and that cardioversion of AFI is associated with a significant degree of atrial stunning and formation of spontaneous echo contrast.

During cardioversion, skin burns result from current preferentially flowing at the electrode edge. We tested new electrodes with high perimeter impedance to yield more uniform current distribution; these electrodes reduced histopathologic skin injury.

Atrial fibrillation (AF) has captured the imagination of clinical investigators who have initiated trials to examine several aspects of this multifaceted arrhythmia. We will review the protocol designs of ongoing trials that are examining the relative value of rhythm versus rate control, new methods for pharmacologic restoration and maintenance of sinus rhythm (including prophylaxis after cardiac surgery), and nonpharmacologic interventions such as pacing and atrial defibrillation. We antic ipate that the results of these studies will have a major impact on the care of patients with AF in the new millennium.

Based on multiple studies, clear, guided anticoagulation therapy is recommended for patients with atrial fibrillation. The value of anticoagulation therapy in patients with atrial flutter, however, is less well established. Little is known about the incidence of thromboembolism in patients with atrial flutter. We evaluated the risk of thromboembolism in 191 consecutive unselected patients referred for treatment of atrial flutter. A history of embolic events was noted in 11 patients. Acute embolism (<48 hours) occurred in 4 patients (3 after direct current cardioversion, 1 after catheter ablation). During follow-up of 26+/-18 months, 9 patients experienced thromboembolic events. During the follow-up, the overall embolic event rate (including acute embolism and thromboembolic events during follow-up) was 7 % in this patient population. Risk indicators for an embolic event in an univariate analysis were organic heart disease (p = 0.037), depressed left ventricular function (p = 0.02), history of systemic hypertension (p = 0.004), and diabetes mellitus (p = 0.0038). Using multivariate analysis, a history of hypertension was the only independent predictor for elevated embolic risk in this patient population (odds ratio = 6.5; 95% confidence intervals 1.5 to 45). Thus, the thromboembolic risk is higher than previously recognized for patients with atrial flutter. Anticoagulation therapy may decrease this risk.

To establish possible myocardial damage by direct-current countershock, we measured plasma levels of troponin T after electrical cardioversion in 33 nonselected patients with atrial fibrillation or flutter. Unchanged normal levels of troponin T indicate that significant myocardial cell injury by shocks in the usual dosage is unlikely to occur.

Fourteen patients with typical atrial flutter underwent pacing from the low lateral right atrium and the proximal coronary sinus in normal sinus rhythm before and after catheter ablation. During low lateral right atrial pacing, a positive change in P-wave morphology in the inferior leads was noted in every patient (n = 12) in whom bidirectional block was achieved; no recurrence was noted in any of these patients.

Fifty patients with symptomatic type I atrial flutter in whom termination of the arrhythmia with transesophageal stimulation was unsuccessful were randomized to undergo a repeat procedure after intravenous propafenone (n = 25) or placebo (n = 25). Immediate sinus rhythm recovery rate was 36% in the propafenone group and 4% in the placebo group (p = 0.005), indicating that intravenous propafenone increases the rate of successful transesophageal stimulation and can be used when a first attempt at conversion is ineffective.

Amiodarone is effective for long-term maintenance of sinus rhythm after electrical cardioversion of refractory atrial fibrillation or flutter. To examine its efficacy and safety for pharmacologic conversion of these arrhythmias, we studied 129 patients with refractory atrial fibrillation or flutter who had failed previous intensive conventional antiarrhythmic treatment. In anticipation of electrical cardioversion, patients were loaded with amiodarone, 600 mg/day during a 4-week period. The main outcome measure was pharmacologic conversion during this period. During the loading period, 23 patients (18%) converted to sinus rhythm. When analyzed in a multivariate model, conversion was related to desethylamiodarone plasma level (p = 0.0006), arrhythmia duration (p = 0.04), left atrial area (p = 0.02), and concomitant treatment with verapamil (p = 0.01). During ongoing atrial fibrillation after loading, the ventricular rate decreased from 100 +/- 25 to 87 +/- 27 beats/ min (p <0.001). Amiodarone appeared to be safe and did not have to be discontinued because of intolerable side effects. Thus, amiodarone loading is safe and is still able to convert refractory atrial fibrillation or flutter. Conversion is related to increased desethylamiodarone plasma levels and concomitant treatment with verapamil. Because prolonged loading may increase desethylamiodarone plasma concentrations, this may enhance efficacy and obviate the need for electrical cardioversion.