Tilt-table testing of patients with pacemaker and recurrent syncope.

Area of Science:

• Cardiology
• Electrophysiology
• Nephrology

Background:

• Recurrent syncope in pacemaker (PM) patients presents diagnostic challenges due to multifactorial etiology.
• Pacemakers are often implanted for conditions other than neurally mediated syncope.

Purpose of the Study:

• To investigate the diagnostic utility of head-up tilt table testing (HUT) in pacemaker patients experiencing syncope or presyncope.
• To elucidate the mechanisms of syncope in patients with pacemakers.

Main Methods:

• A cohort of 41 pacemaker patients referred for syncope underwent standard head-up tilt table testing (HUT) with nitroglycerine provocation.
• Patient data including demographics, resting vitals, fluid intake, and pacing parameters were collected.

Main Results:

• Head-up tilt table testing (HUT) demonstrated a high diagnostic yield, with 54% of patients exhibiting a positive response.
• Vasodepressor or orthostatic hypotensive responses were the most common (72% of positive tests).
• Cardioinhibitory responses leading to syncope were also observed, though less frequent.

Conclusions:

• Head-up tilt table testing (HUT) is a valuable diagnostic tool for evaluating syncope in patients with pacemakers.
• The primary mechanisms identified were vasodepressor and orthostatic hypotension, but cardioinhibitory responses should also be considered.