Intravenous cannulation alters the specificity of head-up tilt testing for vasovagal syncope in elderly patients.
Prolonged head-up tilt is increasingly used as a diagnostic test for vasovagal syncope. Its sensitivity is reported to increase with the concurrent administration of intravenous isoprenaline. False-positive responses are common in young controls particularly following intravascular instrumentation. We studied the influence of intravenous cannulation alone on responses to head-up tilt in ten healthy elderly subjects. All remained asymptomatic during tilt when non-cannulated whilst five developed symptomatic hypotension following cannulation. Thus, intravascular instrumentation influences responses to held-up tilt in elderly subjects; the significance of positive responses obtained using intravenous isoprenaline in this age group requires further evaluation.
McIntosh
S J
SJ
Department of Medicine/Geriatric Medicine, Royal Victoria Infirmary, Newcastle upon Tyne.
Lawson
J
J
Kenny
R A
RA
D000368:Aged; D001794:Blood Pressure; D002406:Catheterization, Peripheral; D005189:False Positive Reactions; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D012680:Sensitivity and Specificity; D013575:Syncope / Q000175:diagnosis* / Q000209:etiology / Q000503:physiopathology; D018667:Tilt-Table Test; D014630:Vagus Nerve / Q000503:physiopathology; D014664:Vasodilation; D014680:Veins