Sex differences in exercise induced left ventricular dysfunction in patients with syndrome X

Area of Science:

• Cardiology
• Nuclear Cardiology
• Cardiovascular Physiology

Background:

• Syndrome X presents with chest pain and ischemic evidence despite normal coronary arteries, often without vasospasm.
• Previous studies have not consistently identified sex-specific differences in the presentation or evaluation of Syndrome X.

Purpose of the Study:

• To investigate exercise-induced left ventricular dysfunction in patients with Syndrome X.
• To determine if sex influences the occurrence and characteristics of exercise-induced left ventricular dysfunction in Syndrome X.
• To explore the relationship between exercise capacity and left ventricular dysfunction in this patient group.

Main Methods:

• Retrospective review of clinical, electrocardiographic, and scintigraphic data from 32 patients (18 men, 14 women) with Syndrome X.
• First-pass radionuclide angiography was used to assess resting and exercise left ventricular ejection fraction (LVEF) and regional wall motion.
• Correlation analysis was performed between clinical variables, scintigraphic findings, and exercise duration.

Main Results:

• Resting LVEF was normal (>50%) in all subjects, with no significant sex difference.
• Exercise significantly decreased LVEF overall (57.4%). A fall >5% occurred in 17 subjects, with regional wall motion abnormalities in 12.
• Women exhibited a significant LVEF fall on exercise (71% vs. 39% in men) and more dyskinetic segments (57% vs. 22% in men). Exercise duration was shorter in women and correlated with LVEF changes.

Conclusions:

• Exercise-induced left ventricular dysfunction is common in Syndrome X patients with normal coronary arteries.
• Women with Syndrome X are more likely to experience exercise-induced left ventricular dysfunction and have lower exercise capacity.
• Patient sex is a critical factor in interpreting non-invasive evaluations for suspected Syndrome X.