Tachycardia: PVCs on a 2 minute rhythm strip made frequent PVCs on ambulatory ECG monitoring more likely

Clinical bottom line (level 4)

  1. 30% of symtomatic patients refered for ambulatory ECG had frequent premature ventricular contractions.
  2. PVCs on a 2 minute rhythm strip made finding 10 or more PVCs per hour on ambulatory monitoring more likely (LR + 17) .
  3. No PVCs on a 2-minute rhythm strip could not safely rule out frequent PVCs on ambulatory monitoring.
Evenson et al: Journal of Clinical Epidemiology 2000; 53 : 491-497
Expires October 2004

The study

Setting: university hospital, USA

252 patients (aged ?, ?% male) refered for a clinically indicated continuous ambulatory ECG monitor (22% syncope or dizziness, 18% angina or ischaemia; 19% palpitations; 41% arrhythmias)

Excluded if
  • aged < 18
  • institutionalised
  • had a pacemaker
  • any of the following on rhythm strip; sick sinus syndrome, atrial fibrillation, or atrial flutter


    Independent ?blinded reference standard, applied in all patients from a consecutive inappropriate spectrum.
    Reference standard:
    • ambulatory ECG monitoring for 24 hours: considered abnormal if 10 or more PVCs per hour
    Diagnostic test: 2-minute continuous rhythm strip read by a cardiologist

    The evidence

    pre-test probability of 10 or more PVCs/hour: 18%, (95% CI: 15% to 22%)

    diagnostic test 10 or more PVCs/hour < 10 PVCs/hour LR+
    (95% CI)    		 post-test probability LR-
    (95% CI)    		 post-test probability
    PVCs on 2-min rhythm strip 42 6 16.8
    (7.5 to 38)     		88% 0.45
    (0.34 to 0.58)     		16%
    total 74 178

    Citation

    1. Evenson KR, Lamar Welch VL, Cascio WE, et al: validation of a short rhythm strip compared to ambulatory ECG monitoring for ventricular ectopy. Journal of Clinical Epidemiology 2000; 53 : 491-497
    Search Terms: from ACP Journal Club other articles noted
    Contributor: Chris Ball, October 2001
    Reviewer:

    Clinical Question.
    Patient symptomatic and referred for ambulatory ECG monitoring
    Intervention or Exposure 2 minute ECG rhythm strip
    Outcome 10 or more premature ventricular contractions (PVCs) per hour