[X syndrome: does left ventricular myocardial perfusion suffer during exercise?]

Area of Science:

• Cardiology
• Nuclear Cardiology
• Exercise Physiology

Background:

• X syndrome presents with clinical signs of coronary heart disease, including anginal episodes.
• The underlying cardiac pathophysiology in X syndrome requires further elucidation.
• Myocardial perfusion abnormalities may be a key feature of X syndrome.

Purpose of the Study:

• To investigate myocardial perfusion during exercise in patients with X syndrome.
• To compare exercise-induced perfusion defects in X syndrome with coronary artery disease (CAD).
• To assess the severity of perfusion impairments in X syndrome relative to CAD severity.

Main Methods:

• Thallium-201 myocardial scintigraphy was performed on 16 patients with X syndrome.
• A control group of 11 patients with one-coronary artery disease was included.
• Bicycle ergometry was used to induce stress during scintigraphy.

Main Results:

• All 16 patients with X syndrome demonstrated local myocardial perfusion impairments during exercise.
• Perfusion defects were observed in the territories of various coronary vessels.
• Impairments in X syndrome were comparable to moderate coronary artery stenosis but less severe than critical stenosis.

Conclusions:

• Patients with X syndrome exhibit significant exercise-induced myocardial perfusion impairments.
• These perfusion defects correlate with clinical anginal episodes, suggesting underlying coronary issues.
• The severity of perfusion impairment in X syndrome is less than critical coronary artery stenosis.