Syncope: electrophysiologic studies detected arrhythmias in patients with unexplained syncope.

Clinical bottom line (level 4)

Electrophysiologic studies detected many arrhythmias in patients with unexplained syncope.
Performing EPS after Holter monitoring added little in detecting arrhythmias.

Denes and Ezri: PACE 1985; 8 (1): 424-435

Expires October 2004

The study

Setting: medical centre, USA

50 patients (aged range 14 to 81 years; mean 57, 66% male) referred for electrophysiologic with unexplained syncope

The study was a case series.
All patients had full history and examination, ECG, CXR, EEG, and a CT/brain scan/ cerebral angiography or cardiac catheter/ echocardiogram as required. All patients had at least 24 hours of Holter monitoring.
Patients had electrophysiology unsedated: three electrodes at high right atrium, bundle of His, right ventricle.

The evidence

differential diagnosis	number of patients	prevalence (95% CI)
abnormal rhythm	37	74% (62% to 86%)
abnormal sinus node	15	30% (17% to 43%)
abnormal AV node	7	14% (4.4% to 24%)
long HV interval	4	8.0% (0.48% to 16%)
paroxysmal SVT	6	12% (3.0% to 21%)
ventricular tachycardia/ fibrillation	4	8% (0.48% to 16%)
carotid sinus syndrome	12	24% (12% to 36%)

diagnostic test	EPS positive	EPS negative	LR+ (95% CI)	LR- (95% CI)
Holter positive	16	5	1.12 (0.52 to 2.45)	0.92 (0.55 to 1.54)
total	37	13

Comments

EPS no better than chance at detect any arrhythmia found on Holter monitoring. Suggests that both EPS and Holter are missing arrhythmias, or that EPS is inducing new ones unrelated to syncope.

Citation

Denes P, and Ezri MD: The role of electrophysiologic studies in the management of patients with unexplained syncope. PACE 1985; 8 (1): 424-435

Contributor: Chris Ball and Clare Wotton, October 2000
Reviewer:

_{Clinical Question.}

_Patient	_{unexplained syncope}
_{Intervention or Exposure}	_{electrophysiologic studies}
_Outcome	_{detecting arrhythmias}