Overview
Functional coronary diagnostics is concerned with the dynamic changes in vessel diameter, pressure ratios and blood flow in the large and small coronary vessels. The Andreas Gruentzig Cardiac Catheterization Laboratories offer patients a wide range of functional examinations:
- Fractional flow reserve (FFR and iFR) can be used to measure the blood supply to the heart. This very precise technique enables the physician to determine whether a vasoconstriction is the cause of a relevant circulatory disturbance of the heart muscle, which would necessitate stent placement. The examination may require the administration of a drug (adenosine). Side effects of this substance (e.g. chest pain, dizziness, shortness of breath) are rare and only of short duration (seconds).
Two physicians from our team performing and interpreting an FFR measurement. The values of the measurement show that the narrowing in the coronary vessel must be treated with a stent.
- Vasoreactivity testing is performed on patients who complain of chest pain but who do not have evidence of vasoconstriction on conventional coronary angiography. During vasoreactivity testing, the physician injects acetylcholine into the coronary artery to determine whether the patient is prone to vasoconstriction (spasm), which is responsible for the discomfort. The treatment of a proven spasm tendency can then be established specifically with medication.
The left section of the image shows a tightening of the anterior vessel (spasm, white arrow) after acetylcholine administration. The image section on the right shows how the vessel wall rapidly relaxes again after administration of nitroglycerin (white arrow).
- Restricted blood flow in the smallest blood vessels (with diameter less than 400 µm) is called microcirculatory dysfunction. The small vessels that supply blood to the heart muscle are not visible in conventional coronary angiography. Modern techniques allow coronary resistance to be measured to identify a circulatory disturbance in the microcirculation. Drug treatment of a detected microcirculatory disturbance can then be established in a targeted manner.