Cardioscopic observation of subendocardial microvessels in patients with coronary artery disease

Area of Science:

• Cardiovascular Medicine
• Cardiac Physiology
• Interventional Cardiology

Background:

• Coronary microvessels are crucial for myocardial ischemia and cardiac function.
• In vivo functional properties of individual microvessels in coronary artery disease patients remain largely unknown.
• Direct observation of these microvessels has been limited.

Purpose of the Study:

• To investigate the in vivo functional properties of subendocardial coronary microvessels in patients with coronary artery disease.
• To determine the relationship between microvessel blood filling patterns and left ventricular contractile state.

Main Methods:

• Cardioscopy was used to observe subendocardial arterial microvessels (AMs) and venous microvessels (VMs) in 149 patients with coronary artery disease.
• Patients included those with stable angina and old myocardial infarction.
• Microvessel filling patterns were analyzed in relation to regional left ventricular wall motion (normokinetic, hypokinetic, akinetic, dyskinetic).

Main Results:

• Microvessels in normally contracting (normokinetic-hypokinetic) segments filled during diastole and collapsed during systole.
• Microvessels in akinetic-to-dyskinetic segments filled during systole and collapsed during diastole.
• No significant correlation was found between filling timing, coronary stenosis severity, or collateral development.

Conclusions:

• The timing of blood filling in coronary AMs and VMs is dictated by the regional left ventricular contractile status in patients with coronary artery disease.
• Preserved contraction facilitates diastolic filling, while impaired contraction leads to systolic filling.
• Further research is needed to explore these phenomena in other heart disease categories.