Which test is most appropriate to evaluate vasodepressor syncope related to standing or posture?

• A. Tilt-table testing
• B. Cardiac catheterization
• C. Echocardiogram
• D. Holter monitoring

Answer: (A)

Fainting that happens with standing is usually due to a reflex that causes blood vessels to dilate and BP to drop when upright. To evaluate this under controlled conditions, a tilt-table test is the best choice because it recreates the upright posture and orthostatic stress while closely monitoring blood pressure and heart rate. By gradually tilting the patient from flat to near-vertical, clinicians can provoke the syncope and see how the body responds, helping distinguish a vasodepressor (BP drops primarily with little heart-rate change) from a cardioinhibitory form ( significant slow heart rate or pauses) or a mixed pattern. If initial tilting is negative but suspicion remains, pharmacologic provocation can increase sensitivity to reveal the abnormal reflex.

Echocardiography checks heart structure and function, useful for ruling out a structural cause but not for reflex-mediated fainting. Holter monitoring looks for arrhythmias during daily life, which helps if an arrhythmic cause is suspected, but it doesn’t directly reproduce orthostatic-induced syncope. Cardiac catheterization is invasive and targets coronary or structural issues, not evaluation of vasodepressor syncope.