[Paroxysmal atrial fibrillation: main cause of syncope in hypertrophic cardiomyopathy].
The aim of this retrospective study was to determine the mechanism of syncope in idiopathic hypertrophic cardiomyopathy (HCM). An electrocardiographic study was undertaken in 43 patients with HCM: 27 (Group I) had a history of syncope and 16 (Group II) had no history of syncope but were investigated for conduction defects (n = 7) or unsustained ventricular tachycardia (VT) (n = 9). The stimulation protocol used programmed atrial pacing with 1 and 2 extrastimuli and ventricular pacing using up to 3 extrastimuli delivered at 2 sites. The following results were obtained: sustained atrial fibrillation (AF) (> 1 min) was induced in 21 patients in Group I (78%), 4 in Group II (25%); VT was induced in 3 patients in Group I (11%), and 3 in Group II (19%); infra-Hisian block was detected in 1 patient in Group I. The mechanism of syncope was elucidated in 23 patients in Group I (85%): one atrioventricular block 1 sinus node dysfunction, 18 atrial fibrillations, 2 associations of AF-VT and 1 VT. The authors conclude that the prevalence of inducible AF was higher in patients with HCA and syncope than in controls and HCM without syncope: this was the only detectable difference in 67% of patients with unexplained syncope. Paroxysmal AF could therefore explain malaise or syncope in up to 2/3 of cases of HCM.
Service de cardiologie A, CHU Brabois, Vandoeuvre.
B
B
Brembilla-Perrot
A
A
Terrier de La Chaise
D
D
Beurrier
D000328:Adult; D000368:Aged; D000404:Ajmaline; D001145:Arrhythmias, Cardiac / Q000209:etiology; D001281:Atrial Fibrillation / Q000150:complications* / Q000209:etiology; D002304:Cardiac Pacing, Artificial / Q000009:adverse effects; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications*; D005260:Female; D006801:Humans; D007545:Isoproterenol; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D013575:Syncope / Q000209:etiology* / Q000503:physiopathology
D000404:Ajmaline; D007545:Isoproterenol
La fibrillation auriculaire paroxystique: principale cause de syncope dans la cardiomyopathie hypertrophique?