Syncope: more arrhythmias were detected the longer Holter monitoring was worn.

Clinical bottom line (level 4)

  1. In patients with syncope, Holter monitoring over 72 hours detected twice as many arrhythmias as 24 hours worth.
Bass et al: Archives of Internal Medicine 1990; 150: 1073-1078
Expires October 2004

The study

Case series with ?objective ?blinded outcomes, not adjusted for confounding factors, not validated in an independent set of patients.

Setting: acute hospital, USA

95 patients (aged range 17 to 97 years; mean 61, 59% female) in- and out-patients with syncope (at least one episode within three months) and no specific cause found on history, physical or 12 lead ECG

Excluded if
  • previously evaluated
  • pharmacological or electrical cardioversion required
  • <18 years old
  • tonic-clonic movements, post-ictal or aura


    • All patients had three days of Holter monitoring (83% consecutive). Monitored for mean of 71.2 hours.

    100%? followed for 1-3 days
    Outcomes studied:
  • major abnormality detected each day: day 1 arrhythmia (ventricular tachycardia for three or more beats, sinus or ventricular pause > 2 sec, bradycardia < 30 bpm, Mobitz II block, complete heart block)
  • major abnormality detected each day: day 2
  • major abnormality detected each day: day 3

    • The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    major abnormality detected each day: day 1 1-3 days 14/95 15%
    (7.6% to 22%)
    major abnormality detected each day: day 2 1-3 days 9/95 9.5%
    (3.6% to 15%)
    major abnormality detected each day: day 3 1-3 days 3/95 3.2%
    (0.7% to 9.0%)

    Comments

    1. How many arrhythmias did Holter monitoring miss?

    Citation

    1. Bass E, Curtiss EI, Arena VC, et al: the duration of Holter monitoring in patients with syncope: Is 24 hours long enough?. Archives of Internal Medicine 1990; 150: 1073-1078
    Contributor: Chris Ball and Clare Wotton, October 2000
    Reviewer:

    Clinical Question.
    Patient syncope
    Intervention or Exposure Holter monitoring
    Outcome detecting arrhythmias