Differences in Mechanisms and Outcomes of Syncope in Patients With Coronary Disease or Idiopathic Left Ventricular Dysfunction as Assessed by Electrophysiologic Testing

Abstract

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.

Increased sensitivity of electrophysiological study by isoproterenol infusion in unexplained syncope

“…Various causes of syncope were revealed by isoproterenol infusion; these results were in accordance with other studies: ventricular tachycardia [19,34], but also bradyarrhythmias [35], vagal hypertonia [32,35,36] or supraventricular tachyarrhythmias [35,37], were reported as possible causes of syncope in patients with heart disease [38].…”

Age, conduction defects and restrictive lung disease independently predict cardiac events and death in myotonic dystrophy

“…Electrophysiological study (EPS) was performed in the absence of cardioactive drugs if ECG showed significant changes, if arrhythmia was found during Holter monitoring or when symptoms occured. The protocol was previously reported and included the assessment of sinus node function and atrioventricular conduction, and a programmed atrial stimulation [8].…”

“…-conduction defect on ECG faced with isolated or associated first degree atrioventricular block, left anterior hemiblock or bundle branch block. -Holter arrhythymia in the presence of 2nd degree atrioventricular block, sinus bradycardia less than 40 b/min, sinus pause greater than 3 s, sustained atrial fibrillation N 1 min or ventricular tachycardia N 30 s observed in 24 h Holter monitoring -abnormal electrophysiological findings were categorized according to the criteria previously described by our group [8] as follows: i) sinus node dysfunction if the corrected sinus node recovery time was longer than 550 ms; ii) conduction disturbances, if atrioventricular Wenckebach block occurred at a pacing rate less than 90 b/min, or the HV interval was greater than 60 ms in the case of fine QRS complex or right bundle branch block, greater than 70 ms in the case of left bundle branch block or if infrahisian second degree atrioventricular block occurred at a pacing rate less than 150 b/min; and iii) inducible supraventricular tachyarrhythmia if it was sustained (N 3 min), and inducible ventricular tachyarrhythmia if it was sustained (N30 s) or required termination before 30 s due to hemodynamic intolerance.…”

Does syncope require rhythmic and non-rhythmic evaluation in patients with previous MI?

“…The following invasive studies were performed: (1) right and left angiography and coronary angiography was indicated in 301 patients; (2) complete EPS according to a protocol previously reported12 was systematic. The protocol included assessment of sinoatrial conduction function and atrioventricular conduction.…”

“…Abnormal electrophysiological findings were categorised as sinus node dysfunction, conduction disturbances, hypervagotonia, inducible supraventricular tachyarrhythmia or inducible ventricular tachyarrhythmia (VT/VF) according to classical diagnostic criteria 12. When several anomalies were noted, including the induction of a ventricular tachyarrhythmia, the presumed cause for syncope was categorised in ventricular tachyarrhythmia.…”