Heart failure: a normal ECG made left ventricular systolic dysfunction less likely

Clinical bottom line (level 2b)

Roughly a fifth of patients referred for echocardiography had impaired left ventricular systolic function.
Patients with an abnormal ECG were at increased risk of having impaired LV function (LR+2.4) - further testing was required.
Patients who had a normal ECG were much less likely to have impaired LV function (LR-0.10) .

Davie et al: British Medical Journal 1996; 312: 222-

Expires October 2003

The study

Setting: university hospital, UK

534 patients (aged range 17 to 94 years, ?% male) referred for echocardiography

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

echocardiography performed by an experienced technician

Diagnostic test: major abnormality on ECG: atrial fibrillation, previous myocardial infarction, left ventricular hypertrophy, bundle branch block or left axis deviation (reviewed by 2 cardiology registrars). ECGs were considered normal if there was atrial enlargement, bradycardia or tachycardia, broadening of the QRS complex, poor R wave progression, right axis deviation, myocardial ischaemia , first degree atrioventricular block, or non-specific ST-T wave changes.

The evidence

pre-test probability of impaired left ventricular systolic function: 18%, (95% CI: 15% to 21%)

diagnostic test	impaired left ventricular systolic function	preserved LV systolic function	LR+ (95% CI)	post-test probability	LR- (95% CI)	post-test probability
abnormal ECG	90	169	2.4 (2.1 to 2.8)	35%	0.10 (0.047 to 0.22)	2%
total	96	438

Citation

Davie AP, Francis CM, Love MP, et al: value of the electrocardiogram in identifying heart failure due to left ventricular systolic dysfunction. British Medical Journal 1996; 312: 222-

Contributor: Chris Ball and Clare Wotton, October 1999
Reviewer:

_{Clinical Question.}

_Patient	_{suspected heart failure}
_{Intervention or Exposure}	_{abnormal ECG}
_Comparison	_{echocardiography}
_Outcome	_{heart failure}