Non-invasive assessment of coronary flow velocity reserve: a new method using transthoracic Doppler echocardiography

Area of Science:

• Cardiology
• Medical Imaging
• Ultrasound Technology

Background:

• Transthoracic Doppler echocardiography (TTDE) enables noninvasive assessment of coronary artery blood flow.
• Evaluating coronary flow velocity reserve (CFVR) is crucial for diagnosing and managing coronary artery disease.
• Previous methods for CFVR assessment were often invasive.

Purpose of the Study:

• To assess the feasibility of contrast-enhanced TTDE with second harmonic imaging for detecting coronary flow.
• To evaluate the coronary flow velocity reserve (CFVR) using TTDE.
• To compare TTDE-derived CFVR with intracoronary Doppler (ICD) measurements.
• To investigate CFVR changes after percutaneous transluminal coronary angioplasty (PTCA) in the left anterior descending artery (LAD).

Main Methods:

• Utilized contrast-enhanced transthoracic Doppler echocardiography (TTDE) with second harmonic technique.
• Administered intravenous adenosine infusion to induce hyperemia for CFVR assessment.
• Compared TTDE-derived CFVR with intracoronary Doppler (ICD) measurements in 80 patients.
• Assessed Doppler signal quality using intravenous Levovist infusion in a subset of patients.

Main Results:

• CFVR was successfully determined in 96% of patients (77 out of 80) using TTDE with adenosine.
• Doppler flow was visualized in all but one patient, indicating high feasibility.
• TTDE-derived CFVR (2.77 +/- 0.65) showed a strong correlation with ICD measurements (2.88 +/- 0.78) (r = 0.87, P < 0.001).

Conclusions:

• Contrast-enhanced TTDE with second harmonic imaging is a feasible technique for assessing coronary flow.
• TTDE provides reliable CFVR data, comparable to invasive ICD measurements.
• This noninvasive method is suitable for monitoring CFVR after PTCA in the LAD.