Measuring Absolute Coronary Flow and Microvascular Resistance by Thermodilution: JACC Review Topic of the Week

Area of Science:

• Cardiology
• Physiology
• Medical Devices

Background:

• Diagnosing coronary microvascular dysfunction (CMD) is challenging due to difficulties in measuring absolute coronary blood flow (Q) and microvascular resistance (Rμ).
• Current diagnostic methods often lack precision and direct quantification of these critical parameters.
• This gap hinders effective clinical assessment and management of CMD.

Purpose of the Study:

• To summarize the principles of thermodilution-derived absolute coronary flow measurements.
• To propose a standardized protocol for performing continuous intracoronary thermodilution.
• To enhance the clinical evaluation of the coronary microcirculation.

Main Methods:

• Continuous intracoronary thermodilution technique for direct quantification of absolute coronary blood flow (Q).
• Calculation of microvascular resistance (Rμ) using the validated thermodilution approach.
• Development of a standardized protocol for consistent and reliable measurements.

Main Results:

• Continuous intracoronary thermodilution provides a simplified and validated method for clinical use.
• The technique enables direct and precise quantification of Q and Rμ.
• Standardization ensures consistent and reliable results for evaluating coronary microcirculation.

Conclusions:

• Continuous intracoronary thermodilution offers a breakthrough in diagnosing coronary microvascular dysfunction.
• Standardized protocols are essential for optimizing the clinical application of this technique.
• This approach significantly enhances the accuracy and reliability of coronary microcirculation assessment.