Syncope: psychiatric problems accounted for some unexplained cases.

Clinical bottom line (level 4)

  1. A quarter of patients with unexplained syncope may have had a psychiatric cause.
  2. This was more likely in patients who felt light-headed or dizzy.
Linzer et al: Psychosomatics 1990; 31 (2): 181-188
Expires October 2004

The study

Setting: teaching hospital, USA

72 patients (aged median 53y, 67% female) unexplained syncope or presyncope following history and physical, hyperventilation, carotid sinus massage, ECG and 24 hour Holter monitoring
Patients were referred to a psychiatrist.
Non-independent unblinded reference standard, applied in all patients from a consecutive appropriate spectrum.
Reference standard:
  • semistructured interview by psychiatrist using DSM-III criteria
Diagnostic test: clinical findings
  • 10% of patients were disabled by their symptoms.

The evidence

pre-test probability of psychiatric cause for syncope: 26%, (95% CI: 16% to 37%)

differential diagnosis number of patients prevalence
(95% CI)
cause: unknown 22 31%
(20% to 41%)
psychiatric (major depression and panic disorder) 17 24%
(14% to 33%)
cardiac 6 8.3%
(1.9% to 15%)
neurological 5 6.9%
(1.1% to 13%)
situational 5 6.9%
(1.1% to 13%)
drug-induced 4 5.7%
(0.27% to 11%)
orthostatic hypotension 2 2.8%
(0.0% to 6.6%)
vasovagal 1 1.4%
(0.0% to 4.1%)
other 9 13%
(4.9% to 20%)


diagnostic test psychiatric cause no psychiatric cause LR+
(95% CI)		 post-test probability LR-
(95% CI)		 post-test probability
light-headed 16 14 3.2
(2.0 to 5.2) 		53% 0.21
(0.08 to 0.61) 		7%
short of breath 10 6 4.6
(2.0 to 11) 		63% 0.53
(0.33 to 0.87) 		16%
dizzy 17 23 2.1
(1.5 to 2.9) 		43% 0.19
(0.05 to 0.70) 		6%
palpitations 8 4 5.6
(1.9 to 16) 		67% 0.63
(0.42 to 0.93) 		18%
tinnitus 10 7 4.0
(1.8 to 9.0) 		59% 0.55
(0.34 to 0.89) 		16%
chest pain 8 5 4.5
(1.7 to 12) 		62% 0.64
(0.43 to 0.95) 		19%
tingling sensation in arms 9 7 3.6
(1.6 to 8.3) 		56% 0.61
(0.39 to 0.94) 		18%
numb feeling 10 10 2.8
(1.4 to 5.6) 		50% 0.58
(0.36 to 0.95) 		17%
blurred/ fading vision 13 17 2.1
(1.3 to 3.5) 		43% 0.46
(0.23 to 0.92) 		14%
room spinning 8 8 2.8
(1.2 to 6.4) 		50% 0.68
(0.46 to 1.02) 		20%
numb or tingling mouth 6 5 3.4
(1.2 to 9.7) 		55% 0.76
(0.55 to 1.04) 		21%
weak 12 23 1.5
(0.92 to 2.3) 		34% 0.65
(0.35 to 1.23) 		19%
nausea 8 15 1.5
(0.75 to 2.9) 		35% 0.81
(0.53 to 1.23) 		22%
near faint 11 24 1.3
(0.79 to 2.1) 		31% 0.77
(0.43 to 1.4) 		22%
sweating 8 17 1.3
(0.68 to 2.5) 		32% 0.85
(0.56 to 1.3) 		23%
sighing 2 1 5.6
(0.54 to 58) 		67% 0.91
(0.78 to 1.1) 		25%
aura 6 13 1.3
(0.57 to 2.9) 		32% 0.91
(0.64 to 1.3) 		25%
abdominal pain 1 6 0.46
(0.06 to 3.6) 		14% 1.1
(0.93 to 1.2) 		28%
total 19 53

  • median age (years):
    • psychiatric cause: 37
    • no psychiatric cause: 60
    • p<0.001
  • number of prodromal symptoms:
    • psychiatric cause: 12
    • no psychiatric cause: 6
    • p=0.0001
  • median frequency:
    • psychiatric cause: weekly
    • no psychiatric cause: monthly
    • p=0.005

Comments

  1. Note wide confidence intervals - this combined with lack of blinding or independence makes results uncertain.
  2. It is possible that having recurrent syncope leads to an increased chance of mental illness.

Citation

  1. Linzer M, Felder A, Hackel A, et al: Psychiatric syncope: a new look at an old disease. Psychosomatics 1990; 31 (2): 181-188
Contributor: Chris Ball and Clare Wotton, October 2000
Reviewer: F K Linda

Clinical Question.
Patient unexplained syncope
Intervention or Exposure prevalence
Outcome psychiatric cause