Single-stage adenosine tilt testing in patients with unexplained syncope.
BACKGROUND
We previously have shown that a 3-minute single-stage adenosine tilt test has a diagnostic yield comparable to a two-stage protocol consisting of a 30-minute drug-free tilt followed by a 15-minute isoproterenol tilt. In this study, we sought to further define the clinical utility of adenosine tilt testing in patients with unexplained syncope by prospectively evaluating test specificity and determining predictors of a positive test response.


RESULTS
The specificity of single-stage adenosine tilt testing was determined using 30 control subjects. To determine the diagnostic yield of this protocol, adenosine tilts were performed in 129 patients with unexplained syncope. The adenosine tilt test protocol had high specificity (100%) but a low overall diagnostic yield (18%). However, the yield was affected significantly by age. In patients </=40 years of age, the tilt test was positive in 15 (41%) of 37 patients, which was significantly greater than the yield in patients between the ages of 41 and 64 years (6/41 patients [15%], P = 0.012) and those >/=65 years of age (2/41 patients [5%], P < 0.0001).


CONCLUSIONS
These data support single-stage adenosine tilt testing in patients </=40 years of age because the diagnostic yield of the test is maximal in this group and the test can be completed in </=3 minutes. Conversely, the diagnostic yield of adenosine tilt testing in patients >40 years of age is low, suggesting that the clinical utility of this protocol is limited in these patients.
Mittal
Suneet
S
Department of Medicine, Division of Cardiology, Cornell University Medical Center, New York, New York 10021, USA. sum2010@med.cornell.edu
Stein
Kenneth M
KM
Markowitz
Steven M
SM
Iwai
Sei
S
Guttigoli
Amit
A
Lerman
Bruce B
BB
D000241:Adenosine; D000328:Adult; D000367:Age Factors; D000368:Aged; D000889:Anti-Arrhythmia Agents; D004562:Electrocardiography; D005260:Female; D006327:Heart Block / Q000175:diagnosis / Q000503:physiopathology; D006329:Heart Conduction System / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012680:Sensitivity and Specificity; D013318:Stroke Volume / Q000502:physiology; D013575:Syncope / Q000175:diagnosis* / Q000503:physiopathology; D018667:Tilt-Table Test
D000889:Anti-Arrhythmia Agents; D000241:Adenosine