Summer syncope syndrome redux.

Area of Science:

• Cardiology
• Geriatrics
• Environmental Medicine

Background:

• Antihypertensive therapy reduces cardiovascular risks but may cause orthostatic hypotension and syncope.
• Hot, dry climates and polypharmacy can exacerbate syncope risk in patients on antihypertensives.

Purpose of the Study:

• To investigate if continuing antihypertensive medication at the same dosage during summer in the Sonoran Desert increases syncopal episodes.
• To assess the link between antihypertensive use, dehydration, and syncope in a desert climate during warmer months.

Main Methods:

• Retrospective chart review of hypertensive patients admitted with syncope (ICD-9 code).
• Patients were categorized as 'cases' (summer months: May-September) or 'controls' (winter months: November-March).
• Primary outcome: clinical dehydration; statistical analysis using Fisher's exact test.

Main Results:

• 834 patients with syncope were reviewed; 477 in summer, 357 in winter.
• Significantly higher syncope cases due to dehydration in summer (40.5%) vs. winter (29%) among antihypertensive users (P = .04).
• No difference in syncope rates based on antihypertensive medication type or number of medications used.

Conclusions:

• Increased syncope events observed in summer among patients in a hot, dry climate taking antihypertensives.
• Data confirm higher syncope rates in summer for this population.
• Recommend judicious reduction of antihypertensive therapy in hot, dry climates during summer.