American Board of Internal Medicine (ABIM) Certification Practice Exam

What is an important diagnostic step for patients presenting with syncope?

1. Routine blood tests

2. Orthostatic vital signs measurement

3. Urinalysis

4. Chest X-ray

The correct answer is: Orthostatic vital signs measurement

Measuring orthostatic vital signs is a critical diagnostic step for patients presenting with syncope because it helps to assess for postural hypotension, a common cause of syncope. This involves measuring the patient’s blood pressure and heart rate while they are lying down, sitting, and standing. A significant drop in blood pressure or an increase in heart rate upon standing can indicate that the patient may be experiencing orthostatic hypotension due to factors such as dehydration, blood loss, or autonomic dysfunction. This assessment is particularly important in determining whether the syncope is related to volume status and autonomic stability, which requires further evaluation and management. It provides immediate data that can guide clinical decision-making regarding the need for fluid resuscitation, medications, or further diagnostic testing. While routine blood tests, urinalysis, and chest X-rays might be useful in broader clinical evaluations, they do not specifically address the immediate physiologic changes associated with syncope. Therefore, they are not as directly relevant to confirming or ruling out causes of syncope as the measurement of orthostatic vital signs.