Syncope: the sensation of syncope did not alone suggest arrhythmia.

Clinical bottom line (level 1b)

Symptoms of dizziness and syncope did not indicate that patients were having arrhythmias.

Clark et al: Chest 1980; 77 (6): 722-725

Expires October 2004

The study

Setting: cardiovascular unit, USA

98 patients (aged range 25 to 82 years; mean 57, ?% male) unexplained dizziness and syncope. All patients had a history and physical, ECG, CXR, routine blood tests and urinalysis.

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

24 hours Holter monitoring. Arrhythmias: sinus bradycardia, second degree heart block, SVT, ventricular arrhythmia

Diagnostic test: symptom diary

The evidence

pre-test probability of significant arrhythmia: 64%, (95% CI: 55% to 74%)

diagnostic test	arrhythmia	no arrhythmia	LR+ (95% CI)	post-test probability	LR- (95% CI)	post-test probability
any symptom over 24 hours	23	18	0.71 (0.45 to 1.12)	56%	1.31 (0.89 to 1.93)	70%
total	63	35

42% of patients had symptoms during the study.
Only 3/41 (7%) of symptoms occurred within 30 minutes of arrhythmia.

Citation

Clark PI, Glasser SP, Spoto E: Arrhythmias detected by ambulatory monitoring: lack of correlation with symptoms of dizziness and syncope. Chest 1980; 77 (6): 722-725

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

_{Clinical Question.}

_Patient	_{unexplained dizziness and syncope}
_{Intervention or Exposure}	_likelihood
_Outcome	_arrhythmias