Blood pressure oscillations during tilt testing as a predictive marker of vasovagal syncope.
OBJECTIVE
During head-up tilt (HUT) testing, a period of haemodynamic instability, marked by oscillations in blood pressure, often precedes vasovagal syncope. We hypothesized that the presence of oscillations in blood pressure during HUT testing predicts a positive diagnosis for vasovagal syncope.


RESULTS
The haemodynamic profiles of 42 consecutive patients non-responsive to passive HUT and glyceryl trinitrate (GTN) provocation ('non-responders') and, contemporaneously, 41 consecutive patients responsive to passive HUT and GTN provocation ('responders') were assigned oscillation-positive or oscillation-negative depending on the presence or absence of a characteristic oscillation in systolic blood pressure which varied by > or =30 mmHg (peak-to-trough). All the non-responders proceeded to an isoprenaline (Iso) challenge test. Of the 42 non-responders, 27 patients were Iso tilt-positive; all of these patients were assigned oscillation-positive. The other 15 non-responders were Iso tilt-negative; of these 9 were assigned oscillation-positive and 6 were assigned oscillation-negative. Of the 41 responder patients, 33 were assigned oscillation-positive, whereas 8 were assigned oscillation-negative. Overall, the presence of oscillations as a diagnostic predictor for vasovagal syncope had a sensitivity of 88% (positive predictive value of 87%) and a specificity of 40% (negative predictive value of 43%).


CONCLUSIONS
In patients non-responsive to passive HUT and GTN provocation, the presence of an oscillating systolic blood pressure varying > or =30 mmHg may still indicate a diagnosis of vasovagal syncope, possibly obviating the need for Iso testing.
Hausenloy
Derek John
DJ
The Hatter Cardiovascular Institute, University College London Hospital and Medical School, 67 Chenies Mews, London, UK.
Arhi
Chanpreet
C
Chandra
Navin
N
Franzen-McManus
Ann-Christine
AC
Meyer
Andrea
A
Sutton
Richard
R
D000328:Adult; D001795:Blood Pressure Determination / Q000379:methods*; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009991:Oscillometry / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019462:Syncope, Vasovagal / Q000175:diagnosis*; D018667:Tilt-Table Test / Q000379:methods*