Syncope: frequent or repetitive PVCs on ECG monitoring predicted death in patients with unexplained syncope.

Clinical bottom line (level 1b)

  1. 12 lead ECG was a useful screening test in patients with syncope though was usually normal.
  2. Around 40% of patients with unexplained syncope had an abnormal Holter recording.
  3. The risk of dying in the next two years was high - many suddenly.
  4. The following were risk factors:
    • frequent or repetitive PVCs
    • sinus pause > 2 seconds
    • congestive heart failure
    • Cr > 2.0 mg/dl
Kapoor et al: American Journal of Medicine 1987; 82: 20-28
Expires October 2004

The study

Prospective cohort study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: university hospital, USA

235 patients (aged range 14 to 90 years; mean 57, 61% female) unexplained syncope following initial work-up.

Factors studied:
  • death
  • frequent or repetitive PVCs premature ventricular contractions: frequent PVCs >10/ hour; repetitive PVCs two or more consecutive
  • congestive heart failure
  • Cr > 2.0 mg/dl
  • sinus pause > 2 seconds
  • frequent or repetitive PVCs




    • Regression analysis performed on risk factors for mortality.

    99% followed for mean 24 months
    Outcomes studied:
  • result of Holter monitoring: normal sinus rhythm with rare premature ventricular contractions (PVC)
  • supraventricular tachycardia
  • AF or flutter
  • ventricular arrhythmia
  • ventricular tachycardia
  • sinus bradycardia
  • heart block
  • atrial arrhythmia
  • death after two years
  • sudden death after two years

    • All patients had history, examination, baseline blood tests, urinalysis, ECG.
    • All had at least 24 hour Holter monitoring (mean 63.7 hours).

    The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    result of Holter monitoring: normal sinus rhythm with rare premature ventricular contractions (PVC) mean 24 months 133/235 57%
    (50% to 63%)
    supraventricular tachycardia mean 24 months 30/235 13%
    (8.5% to 17%)
    AF or flutter mean 24 months 21/235 8.9%
    (5.3% to 13%)
    ventricular arrhythmia mean 24 months 99/235 42%
    (36% to 48%)
    ventricular tachycardia mean 24 months 35/235 15%
    (10% to 19%)
    sinus bradycardia mean 24 months 11/235 4.7%
    (2.0% to 7.4%)
    heart block mean 24 months 9/235 3.8%
    (1.4% to 6.3%)
    atrial arrhythmia mean 24 months 22/235 9.4%
    (5.6% to 13%)
    death after two years mean 24 months 37/235 16%
    (11% to 20%)
    sudden death after two years mean 24 months 16/235 6.8%
    (3.6% to 10%)

    prognostic factor for
    death after two years     		time to outcome control rate (%) adjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    frequent or repetitive PVCs ? 3.7
    (1.8 to 7.5)     		4
    (2 to 10)
    congestive heart failure ? 4.0
    (1.9 to 8.1)     		4
    (2 to 9)
    Cr > 2.0 mg/dl ? 7.9
    (3.3 to 18.9)     		2
    (2 to 4)
    sinus pause > 2 seconds ? 3.3
    (1.1 to 9.6)     		4
    (2 to 76)

    prognostic factor for
    sudden death after two years     		time to outcome control rate (%) adjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    frequent or repetitive PVCs ? 14.9
    (4.0 to 55.7)     		2
    (1 to 6)

    • Initial ECG diagnosed cause in 7% (95% CI 4 to 9%) of cases (5 MI, 22 arrhythmias - 10 VT, 11 bradycardia) .

    Comments

    1. Risk factors need to be prospectively evaluated.

    Citation

    1. Kapoor WN, Cha R, Peterson JR, et al: Prolonged electrocardiographic monitoring in patients with syncope: importance of frequency or repetition of ventricular ectopy. American Journal of Medicine 1987; 82: 20-28
    Contributor: Chris Ball and Clare Wotton, October 2000
    Reviewer:

    Clinical Question.
    Patient syncope
    Intervention or Exposure risk factors
    Outcome death