Differences in mechanisms and outcomes of syncope in patients with coronary disease or idiopathic left ventricular dysfunction as assessed by electrophysiologic testing.
OBJECTIVE
This study evaluated the causes of syncope and the significance and differences in left ventricular (LV) dysfunction, coronary disease, and idiopathic dilated cardiomyopathy (DCM).


BACKGROUND
Risk stratification of and indications for an automated defibrillator could differ according to the cause of LV dysfunction.


METHODS
Electrophysiologic study, including atrial and ventricular programmed stimulation, was performed in 119 patients with coronary disease (group I) and 61 patients with DCM (group II) with an left ventricular ejection fraction (LVEF) <40% and syncope. Patients were followed from one to six years (mean 4 +/- 2 years).


RESULTS
Sustained monomorphic ventricular tachycardia (VT) was induced in 44 group I patients (37%) and 13 group II patients (21%); ventricular flutter (>270 beats/min) or ventricular fibrillation (VF) was induced in 24 group I patients (19%) and 9 group II patients (15%); and various other arrhythmias were identified. Syncope remained unexplained in 34 group I patients (30%) and 16 group II patients (27%). Prognosis depended on the heart disease: VT or VF induction was a predictive factor of mortality in coronary disease and identified a group with high cardiac mortality (46%), compared with patients with a negative study, who had a lower mortality (6%; p < 0.001) than in other studies. Cardiac mortality was only correlated with LVEF in DCM.


CONCLUSIONS
Various causes could explain syncope in 70% of patients with coronary disease and DCM, but differences were noted: VT was frequent in coronary disease with a bad prognosis, and ischemia could explain syncope; in DCM, different causes such as atrial tachycardia could be responsible for syncope, but the prognosis only depended on LVEF.
Brembilla-Perrot
Béatrice
B
Department of Cardiology, CHU of Brabois, Vandoeuvre Les Nancy, France. b.brembilla-perrot@chu-nancy.fr
Suty-Selton
Christine
C
Beurrier
Daniel
D
Houriez
Pierre
P
Nippert
Marc
M
de la Chaise
Arnaud Terrier
AT
Louis
Pierre
P
Claudon
Olivier
O
Andronache
Marius
M
Abdelaal
Ahmed
A
Abdelaah
Ahmed
A
Sadoul
Nicolas
N
Juillière
Yves
Y
D000368:Aged; D000369:Aged, 80 and over; D002311:Cardiomyopathy, Dilated / Q000150:complications* / Q000401:mortality / Q000503:physiopathology; D003324:Coronary Artery Disease / Q000150:complications* / Q000401:mortality / Q000503:physiopathology; D017147:Defibrillators, Implantable; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D018570:Risk Assessment; D013318:Stroke Volume; D016019:Survival Analysis; D013575:Syncope / Q000209:etiology / Q000503:physiopathology* / Q000517:prevention & control*; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000150:complications* / Q000503:physiopathology; D014693:Ventricular Fibrillation / Q000150:complications / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*