Simultaneous occurrence of atrial fibrillation and atrial flutter

INTRODUCTION: Early reports suggested that some patients with "atrial fibrillation/flutter" might have atrial fibrillation in one atrium and atrial flutter in the other. However, more recent conceptions of atrial fibrillation/flutter postulate that the pattern is due to a relatively organized (type I) form of atrial fibrillation. We report the occurrence and ECG manifestations of simultaneous atrial fibrillation and flutter in patients undergoing attempted catheter ablation of atrial flutter. METHODS AND RESULTS: In patients undergoing radiofrequency ablation for atrial flutter, an attempt was made to entrain atrial flutter by pacing in the right atrium. The arrhythmias observed occurred following attempts at entrainment, or spontaneously in one case. Twelve transient episodes of simultaneous atrial fibrillation and flutter were observed in five patients. The atrial fibrillation was localized to all or a portion of one atrium, during which the other atrium maintained atrial flutter. In each case, the surface 12-lead ECG reflected the right atrial activation pattern. No patients had interatrial or intra-atrial conduction block during sinus rhythm, suggesting functional intra-atrial block as a mechanism for simultaneous atrial fibrillation/flutter. CONCLUSION: In certain patients, the occurrence of transient, simultaneous atrial fibrillation and flutter is possible. In contrast to prior studies in which it was suggested that left atrial or septal activation determines P wave morphology, the results of the present study show that P wave morphology is determined by right atrial activation. Functional interatrial block appears to be a likely mechanism for this phenomenon.     

Multifocal atrial arrhythmia—A frequent misdiagnosis? A correlative study using the computerized ECG

All computerized ECGs taken over a 17-week study period were reviewed for the detection of multifocal atrial arrhythmia (MAA)--tachycardia or rhythm--and correlated with the diagnostic statement of the ECG computer system. MAA was identified by the authors in 96 of 11,610 (0.8%) computerized ECGs. In all instances, this specific arrhythmia was misclassified by the computer system as atrial fibrillation. Moreover, during the over-read, only 27.1% of ECGs were correctly diagnosed by the assigned electrocardiographers blinded to this study. MAA is not an uncommon atrial arrhythmia since it was identified in 14% of computerized ECGs interpreted as atrial fibrillation. This study supports the inference that MAA is indeed frequently misdiagnosed by most physicians and the need for improved ECG computer analysis programs for reliable detection of MAA.     

Bipolar atrial sensing thresholds in sinus rhythm and atrial tachyarrhythmias. A comparative analysis in patients with DDDR pacemakers.

Automatic mode switching (AMS) function in dual chamber pacemakers depends on adequate detection of atrial tachyarrhythmias. There are few data on showing how intra-operative atrial signal amplititude during sinus rhythm can predict atrial tachyarrhythmias after pacemaker implantation. In 43 patients undergoing DDDR pacemaker implantation and atrioventricular nodal ablation for the treatment of drug-refractory paroxysmal atrial fibrillation, atrial sensing thresholds during sinus rhythm and during induced atrial tachyarrhythmias (24-48 h after device implantation) were analysed. Five different DDDR pacemaker systems were implanted (Chorus 7034, Ela Medical n = 13; Meta DDDR 1254, Telectronics Pacing Systems n = 12; Vigor DR 1230, Guidant n = 6; Trilogy DR 2364, Pacesetter, n = 2; Kappa DR 401, Medtronic USA n = 10). Every patient received a steroid-eluting, screwing, bipolar atrial lead (Medtronic, Capsure-Fix 4068). The mean P wave amplitude during implantation was 3.91 +/- 1.14 mV. The mean atrial sensing threshold during sinus rhythm and during all modes of induced atrial tachyarrhythmias was 3.35 +/- 1.0 mV, and 1.52 +/- 0.92 mV, respectively (P < 0.001). Atrial fibrillation was induced in 36 patients. The mean sensing threshold during sinus rhythm in this patient group was 3.39 +/- 1.01 mV, the mean sensing threshold during atrial fibrillation was 1.27 +/- 0.56 mV, reflecting a 63% reduction of sensing threshold compared with sinus rhythm (P < 0.001). Atrial flutter was induced in seven patients. The mean sensing threshold during sinus rhythm was 2.92 +/- 1.19 mV, the mean sensing threshold during atrial flutter was 2.79 +/- 1.26 mV, reflecting a reduction of 5% (ns) compared with sinus rhythm. Atrial sensing thresholds during sinus rhythm were significantly correlated with sensing thresholds during atrial tachyarrhythmias (r = 0.44; P < 0.002), but there were significant variations in intra-individual results. The reduction of atrial sensing thresholds between sinus rhythm and induced atrial tachyarrhythmias ranged from 30% to 82%. CONCLUSION: Bipolar atrial sensing thresholds during sinus rhythm are correlated with sensing thresholds during atrial tachyarrhythmias, but there is a large degree of variance in individual patients. A 4:1 to 5:1 atrial sensing safety margin based on sensing threshold during sinus rhythm is a predictor for adequate postoperative detection of atrial tachyarrhythmias and the function of AMS devices.     

Atrial fibrillation is common after ablation of isolated atrial flutter during long-term follow-up

BACKGROUND: Previous studies have shown that the incidence of atrial fibrillation after atrial flutter ablation is approximately 20% among patients presenting with typical atrial flutter and no history of fibrillation. However, studies involving this population have been small, with follow-up typically less than 2 years. OBJECTIVE: The purpose of this study was to provide a more accurate perspective on the long-term risk of atrial fibrillation in patients presenting with isolated typical flutter. METHODS: Clinical records of consecutive patients who had flutter ablations at Presbyterian Medical Center between 1999 and 2004 were assessed (n = 254). Patients with no apparent history of atrial fibrillation before their flutter ablation were identified. Retrospective follow-up data on these patients were obtained by review of medical records from our institution, from patients' cardiologists and primary care physicians, and by direct patient questionnaires. Postablation atrial fibrillation and other arrhythmias were identified by electrocardiography, Holter monitoring, and subsequent clinical records. RESULTS: Postablation atrial fibrillation was identified in 40 (50%) of 80 patients, and an additional three patients presented with atypical atrial flutter, after a mean follow-up of 29.6 +/- 21.7 months. The incidence of atrial fibrillation was progressive, with 49% occurring after 2 years. There was no difference in age, left atrial size, hypertension, structural heart disease, or left ventricular dysfunction in patients who developed atrial fibrillation compared with those who did not. CONCLUSION: Atrial fibrillation occurs in over half of patients who present with isolated typical flutter after cavotricuspid isthmus ablation. Asymptomatic patients should be screened for recurrent arrhythmias indefinitely after ablation. In certain patients, atrial fibrillation and flutter may be different expressions of the same electrical disease, and eradication of the flutter circuit will not prevent the eventual manifestation of atrial fibrillation.     

Differentiating macroreentrant from focal atrial tachycardias occurred after circumferential pulmonary vein isolation

Macroreentrant and Focal Atrial Tachycardias. Background: Atrial tachycardias (ATs) are commonly observed following catheter ablation of atrial fibrillation (AF). The aim of this study was to identify ECG characteristics that differentiate focal from macroreentrant ATs after circumferential pulmonary vein isolation (CPVI). Methods and Results: One hundred and twenty ATs that occurred after CPVI were mapped using a 3‐dimensional mapping system in 87 patients with AF. Further ablation was performed to eliminate the ATs. The surface ECGs of 68 ATs in 41 consecutive patients (Group 1) were analyzed retrospectively to create diagnostic algorithms. The algorithms were tested in the second 46 consecutive patients (Group 2). Patients with macroreentrant AT had lower left atrial (LA) voltage than those with focal AT (1.3 ± 0.3 vs 1.5 ± 0.2 mV, P = 0.01). Focal AT had a higher incidence of a positive polarity in V6 compared with macroreentrant AT (88% vs 55%, P = 0.03). The positive amplitude of the flutter/P waves in V6 was higher for focal AT than macroreentrant AT. The cycle lengths of the focal ATs were longer than those for macroreentrant AT (296 ± 107 vs 244 ± 25 ms, P < 0.001). Right atrial macroreentrant AT had a higher incidence of a negative polarity in at least 1 precordial lead compared with LA macroreentry. The positive flutter waves in V1 could differentiate roof/mitral isthmus dependent from non‐roof/mitral isthmus dependent macroreentry. This algorithm correctly differentiated the focal from macroreentrant ATs with a sensitivity of 94%, specificity of 91%, and predictive accuracy of 92% in Group 2. Conclusion: Different electrophysiological properties may facilitate the differentiation between macroreentrant and focal ATs after CPVI. (J Cardiovasc Electrophysiol, Vol. 22, pp. 748‐755, July 2011)     

Left atrial appendage function in patients with atrial flutter.

OBJECTIVE: To determine whether echocardiographic markers thromboembolic risk differ between patients with pure atrial flutter and patients with atrial flutter and intermittent atrial fibrillation. DESIGN: Patients with atrial flutter were followed up prospectively for 12 months to identify intermittent atrial fibrillation. After the follow up period, transthoracic and multiplane transoesophageal echocardiography were performed to assess left atrial chamber and appendage size, peak emptying velocities, and emptying fraction of the left atrial appendage. The presence of spontaneous echo contrast was also determined. SETTING: Tertiary cardiac care centre. PATIENTS: 20 consecutive patients with atrial flutter; 11 healthy subjects in sinus rhythm served as controls. RESULTS: Intermittent atrial fibrillation was documented in 11 patients by Holter monitoring or surface ECG; atrial fibrillation was not found in the other nine patients. Compared with the patients with pure atrial flutter, patients with atrial flutter and intermittent atrial fibrillation had larger left atrial chamber (mean (SD) 4.5 (0.6) v 3.8 (0.5) cm; 95% confidence interval 0.2 to 1.2; P = 0.01) and appendage areas (6.7 (2.2) v 4.8 (4.9) cm; 95% CI 0.4 to 3.5; P = 0.02), lower left atrial appendage emptying fractions (33 (11)% v 52 (11)%; 95% CI 8 to 29; P = 0.008), and also lower left atrial appendage emptying velocities (0.44 (0.21) v 0.79 (0.27) m/s; 95% CI 0.13 to 0.56; P = 0.005). In addition, a higher incidence of spontaneous echo contrast (11% v 36%) was observed in patients with atrial flutter and intermittent atrial fibrillation. CONCLUSIONS: Left atrial appendage function is depressed and spontaneous echo contrast more frequent in patients with atrial flutter and intermittent atrial fibrillation, as opposed to patients with pure atrial flutter. These data support the concept that patients with atrial flutter and intermittent atrial fibrillation have an increased risk of thromboembolic events and should therefore receive adequate anticoagulant treatment.     

Incidence and clinical significance of transformation of atrial fibrillation to atrial flutter in patients undergoing long-term antiarrhythmic drug treatment.

AIMS: To investigate the rate of transformation of atrial fibrillation to atrial flutter in patients taking antiarrhythmic drugs for the prophylaxis of atrial fibrillation, we retrospectively analysed data from 305 consecutive patients with paroxysmal atrial fibrillation (155 male; mean age 63 +/- 11 years) treated with ventricular rate controlling drugs, antiarrhythmic drugs, or without drugs. METHODS AND RESULTS: At a mean follow-up of 9 months (range 1-24) all patients experienced recurrence of arrhythmia: 48 (14.6%, Group A) suffered Type 1 atrial flutter, and 257 (85.4%, Group B) atrial fibrillation. The relative rate of recurrence of atrial flutter vs atrial fibrillation was similar in patients without treatment or with ventricular rate controlling drugs (from 6.8% to 14.6%, P=ns). However, recurrence was higher (25%) in patients administered antiarrhythmic drug therapy. The relative risk in these patients was 3.02 times greater, compared with patients without treatment, or treated with rate controlling drugs (P<0.001). There were no differences between groups concerning the baseline clinical characteristics and the clinical consequences of the recurrence; patients with atrial flutter had a lower rate of conversion to sinus rhythm (42% vs 64%) and a higher rate of hospital admission (69% vs 36%) compared with those with atrial fibrillation. Six patients (8.5%) experienced 1:1 atrioventricular conduction during atrial flutter with a ventricular rate of 240-280 beats x min(-1). CONCLUSION: Our data suggest that the use of antiarrhythmic drugs for the prophylaxis of atrial fibrillation is associated with a threefold increase in the probability of Type 1 atrial flutter recurrence, as opposed to atrial fibrillation, which may have important clinical consequences, but which did not in our study.     

Incidence of atrial fibrillation post-cavotricuspid isthmus ablation in patients with typical atrial flutter: left-atrial size as an independent predictor of atrial fibrillation recurrence

Introduction: Atrial fibrillation and atrial flutter often coexist. The long-term occurrence of atrial fibrillation in patients presenting with atrial flutter alone is unknown. We report the long-term follow-up in patients who underwent cavotricuspid isthmus ablation for treatment of lone atrial flutter.
Methods and Results: Between January 1997 and June 2002, 632 patients underwent cavotricuspid isthmus ablation for the treatment of typical atrial flutter at the Cleveland Clinic Foundation. Three hundred sixty-three patients were included in this study and followed for a mean duration of 39 ± 11 months. The mean duration of atrial flutter symptoms was 12 ± 5 months. Mean left-atrial size and left-ventricular ejection fraction were 4.2 ± 0.8 cm and 47 ± 13%, respectively. After a mean follow-up time of 39 ± 11 months, 13% (48 of 363) of the patients remained in sinus rhythm. Five percent (18 of 363) of patients experienced recurrence of atrial flutter only. Sixty-eight percent (246 of 363) experienced the onset of atrial fibrillation and 14% (51 of 363) experienced recurrence of atrial flutter and the new onset of atrial fibrillation. Overall, 82% (297 of 363) of the patients experienced new onset of drug refractory atrial fibrillation. Left-atrial size was a predictor of atrial fibrillation recurrence post-atrial flutter ablation.
Conclusion: At long-term follow-up, approximately 82% of patients post-cavotricuspid isthmus ablation for atrial flutter developed drug refractory atrial fibrillation. This finding suggests that elimination of atrial flutter might delay, but does not prevent, atrial fibrillation. Evidence suggests both arrhythmias may share common triggers and such patients may derive a better long-term benefit from anatomical ablative treatment of atrial fibrillation as well.     

Accurate ECG Diagnosis of Atrial Tachyarrhythmias Using Quantitative Analysis: A Prospective Diagnostic and Cost‐Effectiveness Study

Quantitative ECG Analysis . Introduction: Optimal atrial tachyarrhythmia management is facilitated by accurate electrocardiogram interpretation, yet typical atrial flutter (AFl) may present without sawtooth F‐waves or RR regularity, and atrial fibrillation (AF) may be difficult to separate from atypical AFl or rapid focal atrial tachycardia (AT). We analyzed whether improved diagnostic accuracy using a validated analysis tool significantly impacts costs and patient care. Methods and Results: We performed a prospective, blinded, multicenter study using a novel quantitative computerized algorithm to identify atrial tachyarrhythmia mechanism from the surface ECG in patients referred for electrophysiology study (EPS). In 122 consecutive patients (age 60 ± 12 years) referred for EPS, 91 sustained atrial tachyarrhythmias were studied. ECGs were also interpreted by 9 physicians from 3 specialties for comparison and to allow healthcare system modeling. Diagnostic accuracy was compared to the diagnosis at EPS. A Markov model was used to estimate the impact of improved arrhythmia diagnosis. We found 13% of typical AFl ECGs had neither sawtooth flutter waves nor RR regularity, and were misdiagnosed by the majority of clinicians (0/6 correctly diagnosed by consensus visual interpretation) but correctly by quantitative analysis in 83% (5/6, P = 0.03). AF diagnosis was also improved through use of the algorithm (92%) versus visual interpretation (primary care: 76%, P < 0.01). Economically, we found that these improvements in diagnostic accuracy resulted in an average cost‐savings of $1,303 and 0.007 quality‐adjusted‐life‐years per patient. Conclusions: Typical AFl and AF are frequently misdiagnosed using visual criteria. Quantitative analysis improves diagnostic accuracy and results in improved healthcare costs and patient outcomes. (J Cardiovasc Electrophysiol, Vol. 21, pp. 1251‐1259, November 2010)     

Specialty-related differences in the epidemiology, clinical profile, management and outcome of patients hospitalized for heart failure; the OSCUR study. Oucome dello Scompenso Cardiaco in relazione all'Utilizzo delle Risore.

AIMS: This study was designed to identify potential specialty-related differences in the epidemiology, clinical profile, management and outcome of patients hospitalized for congestive heart failure in departments of cardiology or internal medicine. METHODS AND RESULTS: From 1 July to 31 December 1998, we prospectively recorded epidemiological and clinical data from patients with congestive heart failure consecutively admitted to 11 departments of cardiology and 12 departments of internal medicine in Liguria, a northern area of Italy. The overall study population included 749 patients; 22% were treated by cardiologists and 78% by internists (P<0.0001). Patients managed by cardiologists were more likely to undergo echocardiography (92% vs 37%), Holter monitoring (25% vs 3%) and exercise stress testing (20% vs 0.5%) than those managed by internists (P=0.001). At discharge, patients treated by cardiologists were more likely to be prescribed beta-blockers (41% to 4%) and ACE inhibitors (100% to 74%) than those treated by internists (P<0.0001), and the latter medication at higher dosages by cardiologists than internists. In addition, patients followed by cardiologists were younger (70+/-9 to 79+/-1 years;P<0.0001), more likely to be male (61% to 50%;P=0.011) and to have coronary artery disease (57% to 45%;P<0.006) than those followed by internists. Conversely, patients followed by internists were more likely to have diabetes, chronic obstructive pulmonary disease, atrial fibrillation and renal failure (P<0.03). In the overall study population, 53 patients (7%) died during hospitalization. Patients treated by cardiologists had a mortality not significantly different from that of patients treated by internists (10% and 6%, respectively;P=0.067), although congestive heart failure was more severe on admission in patients treated by cardiologists. CONCLUSION: Cardiologists follow published guidelines for congestive heart failure more strictly than internists, but treat a smaller number of patients who are younger, have more severe congestive heart failure and fewer co-morbidities than those managed by internists.     

Physician variation in the management of patients with atrial fibrillation.

OBJECTIVE: To investigate variations in the management of patients with atrial fibrillation among consultant physicians. DESIGN: Questionnaire survey. SUBJECTS: Consultant physicians in England, Wales, and Scotland. RESULTS: 214 consultant physicians (88 cardiologists and 126 non-cardiologists) were surveyed between May and July 1994. Most physicians (47.7%) reported that they saw one to five patients with atrial fibrillation weekly. Some 52% of cardiologists and 40% of non-cardiologists considered that the main factor influencing their decision of whether or not to anticoagulate was the clinical history--that is, heart failure, valve disease, or stroke. When encountering a patient admitted acutely with new onset atrial fibrillation, significantly more cardiologists (66% v 52%, chi 2 = 6.89, P = 0.03) would immediately start anticoagulant treatment, most favouring intravenous heparin. Most physicians would also introduce antiarrhythmic treatment or digoxin, but more cardiologists would attempt immediate pharmacological (39% v 18% of non-cardiologists, P < 0.001) or later electrical (86% v 69%, chi 2 = 11.7, P = 0.003) cardioversion to sinus rhythm, while non-cardiologists tended to prefer "rate control" with digoxin. Although many physicians would not continue antiarrhythmic treatment post-cardioversion, more cardiologists than non-cardiologists would do so (the commonest choice being class III agents) (31% v 17%, P = 0.04). Fewer non-cardiologists would continue anticoagulant treatment post-cardioversion (27% v 69% of cardiologists, chi 2 = 39.8, P < 0.0001). When treating patients with atrial fibrillation, decisions about anticoagulation were usually related to the perceived relative risk of thromboembolism versus haemorrhage derived for each of six case management scenarios in the questionnaire. There was, however, general agreement between cardiologists and non-cardiologists in the use of antithrombotic treatment in the management of lone atrial fibrillation, paroxysmal atrial fibrillation, and patients with atrial fibrillation and mitral valve disease or thyrotoxicosis. CONCLUSION: There is considerable variation in the management of atrial fibrillation, with more cardiologists than non-cardiologists considering cardioversion to sinus rhythm (and the use of antiarrhythmic and anticoagulant treatment post-cardioversion) and thrombo-prophylaxis with anticoagulation. Guidelines on the management of this common arrhythmia are clearly required.     

左房异常与心房颤动的关系

目的探讨左房异常与心房颤动发生的关系。方法应用心电图和动态心电图进行,持续性房颤患者为A组,阵发性房颤、房扑患者为B组,仅有心电图P波增宽的患者为C组,A、B、C三组各40例。所有入选患者均经超声心动图检测左房大小,观察患者窦性心律时心电图P波时限、切迹和P波离散度,并分析与房颤发生的关系。结果房颤男性多于女性,年龄大于60岁者94例(占78.3%),三组中86.7%的患者存在器质性心脏病(104例)。心电图P波切迹明显、P波离散度大者快速房颤发生率高;超声心动图检测左房直径大者房颤发生率高,持续性房颤比阵发性房颤患者左房直径大(p<0.05)。结论左房扩大、房内阻滞及P波离散度增大的患者易发生房颤。     

不纯心房扑动发生机制的心内电生理探讨

目的：心内电生理检查研究体表心电图不纯心房扑动的可能发生机制。方法6例患者经体表心电图证实有不纯心房扑动,射频消融时进行了心内电生理检查,并进行峡部阻断法消融心房扑动。结果：体表心电图与心心内电图同步记录证实,6例不纯心房扑动发作时均为右心房扑动、左心房颤动的心房脱节,心房扑动射频消融均获成功。随访期中2例复发,再次消融成功。结论：不纯心房扑动的发生可能是在右心房扑动的同时,左心房发生一过性颤动的结果。     

Factors associated with early atrial fibrillation after ablation of common atrial flutter. A single centre prospective study.

BACKGROUND: The occurrence of early atrial fibrillation (< or = 6 months) after ablation of common atrial flutter is of clinical significance. Variables predicting this evolution in ablated patients without a previous atrial fibrillation history have not been fully investigated. OBJECTIVES: The aim of the present study was: (1) to identify predictive factors of early atrial fibrillation (< or = 6 months) in the overall population following atrial flutter catheter ablation; (2) to identify predictive variables of early atrial fibrillation following (< or = 6 months) atrial flutter catheter ablation within a subgroup of patients without documented prior atrial fibrillation. METHODS: This study prospectively included 96 consecutive patients (age 65 +/- 13 years; 18 women) over a 12-month period. Their counterclockwise flutter was ablated by radiofrequency, by the same operator, with an 8-mm-tip catheter. Clinical, electrophysiological and echocardiographic data were collected and 27 variables were retained for analysis: age; gender; type of atrial flutter (permanent vs paroxysmal); symptom duration (months +/- SD); pre-ablation history of atrial fibrillation; structural heart disease; left ventricular ejection fraction (%); left atrial size (mm); cava--tricuspid isthmus dimension; septal isthmus dimension; systolic pulmonary pressure > or < or = 30 mmHg; right atrial area; left atrial area; isthmus block; number of radiofrequency applications (+/- SD); antiarrhythmic drugs at discharge; left ventricular diastolic diameter; left ventricular systolic diameter; left ventricular telediastolic volume; left ventricular telesystolic volume; A-wave velocity (cm . s(-1)); E-wave velocity (cm . s(-1)); E/A; isovolumetric relaxation time; E-wave deceleration time; significant mitral regurgitation and flutter cycle length (ms). RESULTS: Of the 96 consecutive ablated patients, early atrial fibrillation was documented in 16 patients (17%). Atrial fibrillation occurred 30 +/- 46 days (range 1 to 171 days) after ablation. Univariate analysis associated an early occurrence of atrial fibrillation with: atrial fibrillation history, left ventricular ejection fraction, left atrial size, left ventricular telesystolic volume, A-wave velocity, significant mitral regurgitation and flutter cycle length. Multivariate analysis using a Cox model found that the only independent predictors of early atrial fibrillation were left ventricular ejection fraction and pre-ablation history of atrial fibrillation. In the subgroup without prior atrial fibrillation history (n=63; 66%), the only independent predictor of early atrial fibrillation was the presence of a significant mitral regurgitation. CONCLUSIONS: In a subgroup of patients without atrial fibrillation history, 8% of patients revealed an early atrial fibrillation. Mitral regurgitation is a strong predictive factor of early atrial fibrillation occurrence with 80% sensitivity, 78% specificity and 98% negative predictive value. These data should be considered in post-ablation management.     

Catheter ablation of atrial flutter due to amiodarone therapy for paroxysmal atrial fibrillation.

AIMS: Antiarrhythmic drug treatment for atrial fibrillation can cause atrial flutter-like arrhythmias. The aim of this study was to clarify the effect of catheter ablation of the tricuspid annulus-vena cava inferior isthmus on amiodarone-induced atrial flutter and to determine the incidence of atrial fibrillation after catheter ablation of amiodarone-induced atrial flutter in comparison to regular typical flutter. METHODS AND RESULTS: Among 92 consecutive patients with typical atrial flutter who underwent isthmus ablation 28 patients had atrial flutter without a history of previous atrial fibrillation (group I), 10 patients had atrial flutter following the initiation of amiodarone therapy for paroxysmal atrial fibrillation (group II) and 54 patients had atrial flutter and atrial fibrillation (group III). Atrial cycle length during atrial flutter in amiodarone-treated patients (group II) (277+/-24 ms) was significantly longer as compared to the cycle length of atrial flutter in group I (247+/-33 ms) and group III patients (235+/-28 ms). The rate of successful transient entrainment and overdrive stimulation to sinus rhythm was not different between patients with (60%) or without amiodarone therapy (group I: 71%, group III: 53%). Successful isthmus ablation with bidirectional conduction block eliminating right atrial flutter was achieved in 90% of amiodarone-treated patients and 93% of patients without amiodarone therapy. In the amiodarone-treated patient group atrial conduction times during pacing in sinus rhythm were significantly prolonged by 20-30% before and after ablation in all regions of the reentrant circuit. During a mean follow-up of 8+/-3 months post-ablation, atrial fibrillation recurred in two of 10 patients on continued amiodarone therapy after successful isthmus ablation. Thus, successful catheter ablation of atrial flutter due to amiodarone therapy was associated with a markedly lower recurrence rate of paroxysmal atrial fibrillation (20%) as compared to patients with atrial flutter plus preexisting paroxysmal atrial fibrillation (76%) and was similar to the outcome of patients with successful atrial flutter ablation without preexisting atrial fibrillation (25%). CONCLUSION: These data suggest that isthmus ablation with bidirectional block and continuation of amiodarone therapy is an effective therapy for the treatment of atrial flutter due to amiodarone therapy for paroxysmal atrial fibrillation.     

Physician variation in anticoagulating patients with atrial fibrillation. Dartmouth Primary Care COOP Project

We investigated variations in the oral anticoagulant treatment of atrial fibrillation by physicians in three specialties: family physicians (or general practitioners), general internists, and cardiologists. Results showed general agreement in the anticoagulation decision regarding patients with either mitral valve disease or a history of chronic alcohol abuse, but substantial disagreement in other categories of patients. Estimations of the risk of embolization and risk of hemorrhage differed widely among all physicians, cardiologists generally rating the embolization risks lower than the other physicians. A physician's treatment decision was strongly related to the relative risk of embolism vs hemorrhage derived for each case. A relationship between physician specialty and treatment decision was also demonstrated, with cardiologists least likely, and family practitioners most likely, to institute anticoagulation in nonrheumatic patients with atrial fibrillation. The reason for this variation appears to be differences in the estimated risk of systemic embolism.     

Permanent atrial fibrillation in heart disease in Spain. The CARDIOTENS study 1999

INTRODUCTION AND OBJECTIVE: Atrial fibrillation is the most common arrhythmia seen in clinical practice. The objective of this study was to know the frequency of atrial fibrillation and the characteristics of patients with atrial fibrillation in the Cardiotens study. MATERIAL AND METHOD: A cross-section study with systematic selection of the study sample. All 32,051 outpatients seen on the same day by 1,159 physicians specialized in primary-care (79%) and cardiology (21%) were prospectively added to a database including history of cardiac disease (heart failure, coronary disease or atrial fibrillation), blood pressure, and ongoing treatment. RESULTS: Atrial fibrillation was present in 25% of patients with previous cardiovascular disease (6,194 patients), the prevalence being 4.8% (1,540/32,051) of the study population. Atrial fibrillation was more frequent in females 29%, (810/2,837) than in males, 22% (730/3,367), p < 0.005). Atrial fibrillation was present in 33% (469/1,420) of patients with heart failure and in 12% (387/3,226) of those with coronary heart disease. Arterial hypertension was diagnosed in 25% of the patients with atrial fibrillation. Only 33% of them were treated with oral anticoagulants (41% of the patients seen by cardiologists and 26% by primary-care physicians, p < 0.005). The antiarrhythmic drug most often used was digoxin (36%). CONCLUSIONS: Atrial fibrillation had the same frequency and epidemiology in Spain as in other Western countries. Antithrombotic therapy is underused by primary-care physicians and cardiologists.     

Criteria for the electrocardiographic diagnosis of atrial flutter improve diagnostic accuracy

Purpose

We previously developed and validated diagnostic criteria for the differentiation of atrial flutter from atrial fibrillation. In this study we examine if the criteria (F waves in the frontal plane and a partially or completely regular ventricular response) can improve the diagnostic accuracy of internists.

Methods

Two groups of 10 internists (1 group given the criteria and 1 not) read a set of electrocardiograms (ECGs) selected from the hospital database with cardiologist-confirmed diagnoses of atrial fibrillation, atrial flutter, or “atrial fibrillation-flutter” (100 each). The final diagnoses of all ECGs were provided by a consensus of electrophysiologists. The criteria also were used to establish the criteria-based diagnoses.

Results

Of the 298 ECGs analyzed, the electrophysiologist diagnosis was atrial fibrillation in 71% and atrial flutter in 29%. The concordance of the internists’ diagnoses with the electrophysiologist consensus diagnoses was 66 ± 12% for those not given the criteria and 81 ± 4% (P <.01) for those given the criteria. The concordance of the internists’ diagnoses with the criteria based diagnoses was 66 ± 12% for those not given the criteria and 83 ± 4% (P <.01) for those given the criteria.

Conclusions

The simple criteria of F waves in the frontal plane and a partially or completely regular ventricular response can be used to improve the differentiation of atrial flutter from atrial fibrillation based on the ECG.     

Persistent Atrial Flutter in Patients Treated for Atrial Fibrillation with Amiodarone and Propafenone:

INTRODUCTION: Antiarrhythmic drugs have been reported to promote the conversion of atrial fibrillation to atrial flutter in patients with paroxysmal atrial fibrillation. However, information about the electrophysiologic mechanism and response to radiofrequency ablation of these drug-induced atrial flutters is limited. Furthermore, the determinants of the development of persistent atrial flutter in patients treated for atrial fibrillation with antiarrhythmic drugs are still unknown. METHODS AND RESULTS: Among the 136 patients treated for atrial fibrillation with amiodarone (n = 96) or propafenone (n = 40), 15 (11%, mean age 65.5 +/- 12.3 years) were identified to have subsequent development of persistent atrial flutter based on surface ECG characteristics during antiarrhythmic drug treatment. The mean interval between the beginning of drug treatment and the onset of atrial flutter was 5.0 +/- 5.5 months. Intracardiac mapping and entrainment studies revealed that 11 patients had counterclockwise typical atrial flutter, and 4 had clockwise typical atrial flutter. All 15 patients underwent successful ablation with creation of complete bidirectional isthmus conduction block. After a mean follow-up of 12.3 +/- 4.2 months, 14 (93%) of 15 patients who underwent successful ablation and continued taking antiarrhythmic drugs have remained in sinus rhythm. Univariate analysis of clinical variables demonstrated that only atrial enlargement was significantly related to the occurrence of persistent atrial flutter. CONCLUSION: In patients with atrial fibrillation, persistent typical atrial flutter might occur during antiarrhythmic drug treatment, and atrial enlargement was a risk factor for the development of such an arrhythmia. Radiofrequency ablation and continuation of pharmacologic therapy offered a safe and effective means of achieving and maintaining sinus rhythm.