The poststenotic vessel segment during dynamic exercise: effect of oral isosorbide-dinitrate

Area of Science:

• Cardiovascular Physiology
• Interventional Cardiology

Background:

• Coronary artery disease (CAD) affects vessel vasomotion.
• Understanding vasomotion in normal, stenotic, and poststenotic segments is crucial for CAD management.

Purpose of the Study:

• To investigate coronary vasomotion in different coronary artery segments during rest, exercise, and after nitrate administration in patients with CAD.
• To assess the effect of oral isosorbide-dinitrate (ISDN) premedication on exercise-induced coronary vasomotion.

Main Methods:

• 18 patients with CAD underwent quantitative coronary arteriography at rest, during exercise, and after sublingual nitroglycerin or ISDN spray.
• Patients were divided into two groups: no premedication (Group 1) and oral ISDN pretreated (Group 2).
• Semi-automatic computer system used for quantitative analysis of vessel cross-sectional area.

Main Results:

• Normal segments showed a slight increase in area during exercise. Stenotic segments narrowed significantly during exercise in untreated patients but not in ISDN-pretreated patients.
• Poststenotic segments exhibited minimal vasomotion during exercise, unaffected by stenosis or oral ISDN.
• Sublingual nitrates increased luminal area in normal and poststenotic segments post-exercise.

Conclusions:

• Poststenotic coronary vasomotion during exercise is minimal and independent of the stenotic segment's vasomotion.
• Oral ISDN effectively prevents exercise-induced narrowing at the stenosis site.
• Nitrate administration improves luminal area in poststenotic segments after exercise.