Summary
Background
Atrial flutter (AFL) and atrial fibrillation (AF) are “fellow-travellers”. AF may be a stable, “isolated” rhythm, a bridge between sinus rhythm and AF, or both arrhythmias can coexist. Whether the characteristics of isolated AFL are different from those of patients with AFL combined with AF is still unclear.
Aim
To compare the clinical characteristics of patients with isolated AFL to those of patients with AFL combined with AF, in a series of patients referred for AFL ablation.
Methods
Seventy-six consecutive patients (mean age 66.9 ± 12.2 years; 53 men) with a history of electrocardiogram-documented paroxysmal or persistent AFL, referred for catheter ablation, underwent clinical work-up including bidimensional echocardiogram. Patients were subdivided into group I (44 with isolated AFL) and group II (32 with AFL and a history of AF).
Results
Underlying heart disease was present in 62 patients (81.6%). Hypertension was the most common cardiac disorder ( n = 44, 57.9%) and was more prevalent in group II than in group I (75.0% vs 45.5%; P = 0.01). Prevalence of prior cardiac surgery was higher in group I (22.7% vs 6.3%; P = 0.04). AFL was persistent in 35 group I patients and 17 group II patients (79.5% vs 53.1%; P = 0.01). Class I or III antiarrhythmic drug use was more frequent in group II (84.4% vs 45.5%; P = 0.001).
Conclusion
This study showed significant differences between patients with isolated AFL and those with AFL combined with AF, in the prevalence of underlying heart disease and the use of antiarrhythmic medication, which were higher when both atrial arrhythmias were combined. In turn, the history of cardiac surgery (including atriotomy), was more common in patients with isolated AFL than in those with AFL combined with AF.
Résumé
Introduction
Une relation étroite existe entre flutter atrial (FLA) et fibrillation atriale (FA). Le FLA peut être une arythmie cardiaque « isolé » et stable, mais aussi un rythme transitoire entre rythme sinusal et FA. Ces deux troubles du rythme peuvent par ailleurs coexister chez le même patient. L’existence d’une différence de caractéristiques cliniques des patients avec FLA isolé de ceux avec FLA et FA associés n’a pas été précédemment étudiée. Nous avons comparé ces deux populations dans une série de patients adressés pour ablation de FLA.
Méthode et résultats
Soixante-seize patients (53 hommes et 23 femmes) avec un âge moyen de 66,9 ± 12,2 ans et un FLA paroxystique ou persistent documenté par ECG, adressés pour ablation endocavitaire de FLA ont bénéficié d’un examen clinique complet incluant une échocardiographie bidimensionnelle. Les patients étaient répartis en deux groupes : groupe I (44 patients) dans lequel les patients avaient un FLA isolé et groupe II (32 patients) dans lequel les patients avaient également un antécédent de FA. Une cardiopathie sous-jacente était présente chez 62 patients (81,6 %). L’hypertension artérielle était l’anomalie la plus fréquente, retrouvée chez 44 patients (57,9 %) et était plus fréquente dans le groupe II que dans le groupe I (75,0 % versus 45,5 % ; p = 0,01). La prévalence d’un antécédent de chirurgie cardiaque avec atriotomie était supérieure dans le groupe I que dans le groupe II (22,7 % versus 6,3 % ; p = 0,04). Le FLA était persistent chez 35 patients du groupe I et 17 patients du groupe II (79,5 % versus 53,1 % ; p = 0,01). La prescription de traitement antiarythmique de classe I ou III était plus fréquente dans le groupe II que dans le groupe I (84,4 % versus 45,5 % ; p = 0,001). Les caractéristiques cliniques des deux groupes étudiés étaient comparables par ailleurs.
Conclusion
Cette étude rapporte des différences cliniques significatives entre les patients avec FLA isolé et ceux avec FLA et FA associés en termes de prévalence de cardiopathie sous-jacente et de prescription de traitement antiarythmique qui étaient supérieures quand les deux troubles du rythme étaient combinés. En revanche, un antécédent de chirurgie cardiaque avec cicatrice d’atriotomie était plus fréquent chez les patients avec FLA isolé que chez les patients avec FLA et FA associés.
Introduction
Atrial flutter (AFL) and atrial fibrillation (AF) are considered to be “fellow-travellers” and to share similar clinical contexts. AFL may be a stable, “isolated” rhythm, a bridge between sinus rhythm and AF, or both arrhythmias can coexist in the same patient. Among patients referred for catheter ablation of AFL, the prevalence of AF before ablation in current literature ranged from 24% to 62% . The follow-up of patients who underwent successful ablation of the cavotricuspid isthmus for isolated AFL showed occurrence of AF in up to 70% of cases . Long-term administration of class I or III antiarrhythmic agents in patients with AF may promote the conversion of AF into AFL in 12.8% to 22.4% of cases . Newly discovered AF has been detected in 8% of patients after AFL ablation, early (< 6 months) after the procedure .
Clinical characteristics of patients with AF have been previously described in a number of population-based studies . Multivariable analysis from the Framingham Heart Study showed that age, male sex, hypertension, congestive heart failure, diabetes and valve disease were independent risk factors for the development of AF . Arrhythmogenic substrates and mechanisms underlying the presence of common AFL are better understood than those of AF and catheter ablation therapy of AFL has been proposed as a first-line treatment because of the limited efficacy of pharmacological therapy and the good results that it achieves. Surprisingly, studies on the clinical characteristics of patients with AFL are scarce. In a population-based study, independent clinical risk factors for AFL development were found to be heart failure and chronic obstructive pulmonary disease, with relative risks being 3.5 and 1.9, respectively. AFL was found to be 2.5 times more frequent in men than in women .
Whether the characteristics of patients with isolated AFL differ from those of patients with AFL combined with AF is still unclear. The aim of this study was to compare the clinical characteristics of patients with isolated AFL to those of patients with AFL combined with AF, in a series of patients referred for AFL ablation.
Methods
From 1 January 2005 to 30 April 2007, 76 consecutive patients with electrocardiogram (ECG)-documented AFL lasting more than 30 seconds were referred to our institution for catheter ablation. The information provided by the clinical and biological work-up was prospectively collected but the analysis was retrospective. Excluded from the study were patients with recent (< 1 month) cardiac surgery, acute pulmonary embolism, pulmonary infection, hyperthyroidism or prior left atrial ablation for the treatment of AF. All patients underwent M mode and bidimensional echocardiogram. ECG diagnosis of AF was made according to Bellet’s definition . AFL was diagnosed when the surface ECG showed highly regular atrial tachycardia greater than 240 beats per minute, with continuous wave and the typical “sawtooth” pattern in the inferior leads. The atrial rate of AFL had to be greater than 200 beats per minute in patients on class I or class III antiarrhythmic agents . Common AFL was defined on the ECG as having negative flutter waves (F waves) in the inferior leads (II, III and VF) and positive F waves in lead V1. The surface ECG of uncommon AFL was defined as having positive F waves in the inferior leads and negative F waves in lead V1. The type of AFL was defined according to the classification described for AF: paroxysmal when the arrhythmia was self-terminating within 7 days and persistent when lasting for more than 7 days . Patients without detectable underlying heart disease or a detectable cause were labelled as having “lone AFL”.
Patients were subdivided into two groups based on the absence or presence of a clinical history and/or of the ECG record of AF. Group I included patients with no history of AF and group II included patients with both AFL and a history of ECG-documented AF (duration > 30 seconds). Clinical characteristics and the use of antiarrhythmic and anticoagulant medications were recorded. ECG (and, when indicated, 24-hour ECG ambulatory recording) and bidimensional echocardiographic findings were reviewed. Hypertension was diagnosed when blood pressure at rest was greater than 140/90 mmHg (or, in a treated patient, by the use of antihypertensive medication). Coronary artery disease was diagnosed when a documented history of myocardial infarction and/or coronary revascularization was present, or if one or more significant (> 70%) obstructive lesion(s) were present on a coronary angiogram. Diagnosis of valvular heart disease was made in patients with moderate to severe valvular regurgitation or on the evidence of mitral stenosis.
Statistical analysis
Results are reported as mean ± standard deviation or number and percentage, as applicable. Qualitative clinical characteristics of patients were examined using Fisher’s exact test or the Khi-square test. The t test was used for quantitative values. A P value less than 0.05 was considered to be statistically significant. All analyses were performed using Microsoft Excel (Microsoft Corporation, Redmond, WA, USA) and SPSS (SPSS Inc., Chicago, IL, USA).
Results
The study included 76 patients with AFL who fulfilled the inclusion criteria. There were 53 men (69.7%) and 23 women (30.3%), with a mean age of 66.9 ± 12.2 years (range 33–90 years), as shown in Table 1 . The mean time from the first episode of AFL to present clinical evaluation was 76 ± 55 days (range 0–240 months). Underlying heart disease was present in 62 patients (81.6%) and included hypertension in 44 patients (57.9%), ischaemic cardiomyopathy in 15 patients (19.7%), valvular heart disease in 10 patients (13.2%), four of whom had rheumatic valve disease and dilated cardiomyopathy in seven patients (9.2%). History of cardiac surgery (including atriotomy) was present in 12 patients (15.8%). AFL occurred 3–43 months after cardiac surgery. None of these 12 patients experienced AFL perioperatively or had documented AFL prior to surgery. Chronic obstructive lung disease was diagnosed in 12 patients (15.8%). Fourteen patients (18.4%) were classified as having “lone AFL”. Among 62 patients with detectable heart disease, 15 were in New York Heart Association class I (24.2%), 24 in class II (38.7%), nine in class III (14.5%) and 14 in class IV (22.4%). A history of thromboembolic event was present in eight patients (10.5%). In no patient was an embolic event the presenting symptom of AFL. Common predisposing factors to thromboembolism were not more common in patients with a history of embolic events than in those without. Hypertension was significantly more common in group II than in group I (75.0% vs 45.5%; P = 0.01). Prior cardiac surgery (including atriotomy) was significantly more frequent in group I than in group II (22.7% vs 6.3%; P = 0.04). The remaining clinical characteristics of the two groups did not differ significantly.
| Total population ( n = 76) | Isolated AFL ( n = 44) | AFL combined with AF ( n = 32) | P | |
|---|---|---|---|---|
| Age (years) | 66.9 ± 12.2 | 66.7 ± 12.5 | 67.2 ± 12.1 | 0.86 |
| Male/female ratio (n/n) | 53/23 | 31/13 | 22/10 | 0.34 |
| Body weight (kg) | 75.6 ± 13.8 | 76.5 ± 13.7 | 74.4 ± 14.1 | 0.64 |
| Height (cm) | 168.5 ± 7.7 | 169.7 ± 6.5 | 166.7 ± 8.9 | 0.11 |
| Systolic BP (mmHg) | 132 ± 14 | 132 ± 15 | 133 ± 13 | 0.71 |
| Diastolic BP (mmHg) | 70 ± 10 | 69 ± 10 | 72 ± 9 | 0.80 |
| NYHA functional class | 2.34 ± 1.09 | 2.30 ± 1.00 | 2.41 ± 1.21 | 0.67 |
| I | 15 (24.2) | 9 (20.5) | 10 (31.3) | * |
| II | 24 (38.7) | 21 (47.7) | 8 (25.0) | * |
| III | 9 (14.5) | 6 (13.6) | 5 (15.6) | * |
| IV | 14 (22.4) | 8 (18.2) | 9 (28.1) | * |
| Underlying heart disease | 62 (81.6) | 33 (75.0) | 29 (90.6) | 0.08 |
| Hypertension | 44 (57.9) | 20 (45.5) | 24 (75.0) | 0.01 |
| Coronary artery disease | 15 (19.7) | 8 (18.6) | 7 (21.9) | 0.72 |
| Dilated cardiomyopathy | 7 (9.2) | 5 (11.4) | 2 (6.3) | 0.69 |
| Non-rheumatic heart disease | 10 (13.2) | 5 (11.6) | 5 (15.6) | 0.73 |
| Rheumatic heart disease | 4 (5.3) | 2 (4.5) | 2 (6.3) | 0.91 |
| Lone AFL | 14 (18.4) | 11 (25.0) | 3 (9.4) | 0.08 |
| Predisposing or associated factors | ||||
| Prior cardiac surgery | 12 (15.8) | 10 (22.7) | 2 (6.3) | 0.04 |
| Bronchopulmonary disease | 14 (18.4) | 9 (20.5) | 5 (15.6) | 0.59 |
| Prior embolic events | 8 (10.5) | 2 (4.5) | 6 (18.8) | 0.06 |
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
