Unexplained syncope evaluated by electrophysiologic studies and head-up tilt testing.

Area of Science:

• Cardiology
• Clinical Electrophysiology

Background:

• Unexplained syncope presents a diagnostic challenge.
• Identifying the cause is crucial for effective management and preventing recurrence.

Purpose of the Study:

• To characterize patient subgroups with unexplained syncope.
• To evaluate the diagnostic yield of electrophysiologic studies and head-up tilt testing.
• To assess the efficacy of therapies guided by these investigations.

Main Methods:

• Retrospective study of 86 patients with unexplained syncope.
• Electrophysiologic studies were performed on all patients.
• Head-up tilt testing was conducted for patients with negative electrophysiologic results.

Main Results:

• Electrophysiologic studies identified causes in 34% of patients (Group 1), often related to ventricular tachycardia and structural heart disease.
• Head-up tilt testing diagnosed causes in 40% of patients (Group 2), with successful management using beta-blockers or disopyramide.
• Syncope remained unexplained in 26% of patients (Group 3).
• Overall, syncope recurred in 10% of patients during follow-up.

Conclusions:

• The combined use of electrophysiologic evaluation and head-up tilt testing diagnoses the cause of syncope in up to 74% of unexplained cases.
• Therapeutic strategies based on these diagnostic findings are effective in preventing syncope recurrence.