Table 3.
Tests Performed During the Syncope Admission
| Test | CardiovascularSyncope, %(n= 284) | 95% CI forDifferenceBetweenCV and UN * | NoncardiovascularSyncope, %(n= 602) | 95% CI forDifferenceBetweenNCV and UN † | UnexplainedSyncope, %(n= 630) | p‡ |
|---|---|---|---|---|---|---|
| Standard cardiac tests | ||||||
| 12-Lead electrocardiogram | 99.6 | (0.0, 3.4) | 95.5 | (−4.4, −0.4) | 97.9 | .001 |
| Telemetry monitoring | 98.6 | (3.5, 10.1) | 82.1 | (−13.7, −6.3) | 92.1 | <.001 |
| Rule-out myocardial infarction § | 46.1 | (−6.1, 7.9) | 36.4 | (−14.3, −3.3) | 45.2 | .002 |
| Exercise test | 5.3 | (−4.6, 2.2) | 3.7 | (−5.3, −0.3) | 6.5 | .08 |
| Holter monitoring | 1.8 | (−5.1, 0.1) | 1.5 | (−4.7, −0.9) | 4.3 | .006 |
| Advanced cardiac tests | ||||||
| Echocardiogram | 27.8 | (4.5, 15.9) | 10.5 | (−11.0, −3.2) | 17.6 | <.001 |
| Cardiac catheterization | 12.7 | (6.4, 13.0) | 1.5 | (−3.2, 0.2) | 3.0 | <.001 |
| Electrophysiology study | 4.9 | (0.7, 5.3) | 0.5 | (−2.6, −0.2) | 1.9 | <.001 |
| Stress thallium | 3.2 | (−0.4, 3.6) | 2.0 | (−1.1, 1.9) | 1.6 | .29 |
| Signal-averaged electrocardiogram | 1.8 | (−0.8, 2.4) | 0.3 | (−1.6, 0.2) | 1.0 | .09 |
| Tilt table | 1.4 | (−0.3, 2.1) | 0.7 | (−0.7, 1.1) | 0.5 | .30 |
| MUGA scan ∥ | 1.4 | (−1.1, 1.9) | 0.5 | (−1.5, 0.5) | 1.0 | .37 |
| Neurologic tests | ||||||
| Computed tomography, head | 11.3 | (−17.6, −6.4) | 20.1 | (−7.8, 1.4) | 23.3 | <.001 |
| Carotid ultrasound | 7.4 | (−8.2, 0.2) | 8.8 | (−6.0, 0.8) | 11.4 | .11 |
| Electroencephalogram | 4.6 | (−16, −6.8) | 8.8 | (−10.9, −3.5) | 16.0 | <.001 |
| Magnetic resonance imaging, brain | 1.8 | (−4.3, 0.5) | 3.8 | (−2.0, 2.2) | 3.7 | .25 |
| Lumbar puncture | 0.4 | (−2.7, 0.3) | 1.0 | (−1.9, 0.7) | 1.6 | .24 |
*
Confidence intervals (95%) for the absolute percentage difference between cardiovascular syncope and unexplained syncope.
†
Confidence intervals (95%) for the absolute percentage difference between noncardiovascular syncope and unexplained syncope.
‡
p Values are derived from overall χ2for differences between the three groups.
§
Defined as the use of telemetry and the measurement of at least two creatine phosphokinase levels in the first 24 hours of admission.
∥
MUGA indicates multiple gated acquisition radionuclide fraction.