Syncope: major arrhythmias occurred in a tenth of patients with unexplained syncope, but were unrelated to symptoms.

Clinical bottom line (level 4)

Symptoms of dizziness and fainting were common in patients with syncope - few related to arrhythmias. Indeed symptoms made a major arrhythmia less likely!
24 hour ECG monitoring detected a major arrhythmia in around 9% of patients with unexplained syncope.

Gibson and Heitzman: American Journal of Cardiology 1984; 53: 1013-1017

Expires October 2004

The study

Setting: university hospital, USA

1512 patients (aged 66% aged >60 years, 54% female) unexplained syncope

Excluded if

unable to use symptom diary

inadequate records

Independent unblinded reference standard, applied in all patients from a consecutive appropriate spectrum.
Reference standard:

cardiac arrhythmia 24 hour ECG monitoring - results reviewed by two independent cardiologists

Diagnostic test: symptoms of syncope, presyncope

The evidence

pre-test probability of major arrhythmia: 8.7%, (95% CI: 7.2% to 10%)

diagnostic test	major arrhythmia	no major arrhythmia	LR+ (95% CI)	post-test probability	LR- (95% CI)	post-test probability
symptoms	6	249	0.25 (0.12 to 0.56)	2%	1.2 (1.1 to 1.2)	10%
total	131	1381

Comments

33% of patients aged > 60 were on medication that could predispose them to arrhythmias or hypotension. Uncertain how many of these arrhythmias related to the syncopal episodes.

Citation

Gibson TC, and Heitzman MR: diagnostic efficacy of 24-hour electrocardiographic monitoring for syncope. American Journal of Cardiology 1984; 53: 1013-1017

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

_{Clinical Question.}