Assessment of Coronary Flow Velocity Reserve by Noninvasive Transthoracic Doppler Echocardiography in Patients with Angiographically Normal Coronary Arteries

Summary： The measurement of coronary flow velocity reserve （CFVR） by transthoracic Doppler echocardiography （TTDE） with invasive intracoronary Doppler flow wire technique （ICD） was validated and the pathological factors which influence CFVR in patients with angiographically normal coronary arteries were analyzed. CFVR was determined successfully in left anterior descending artery （LAD） in 37 of 40 patients with angiographically normal coronary arteries （men 22, women 15, age 20-75 years, mean age 54±12 years）. Coronary flow velocity was measured in the distal LAD by TTDE with contrast enhancement at baseline and during intravenous adenosine infusion of 110 μg/ kg per min within 48 h after ICD technique. Average peak velocity at baseline （APVb）, average peak velocity during hyperemia （APVh） and CFVR determined from TTDE were correlated closely with those from ICD measurements （APVb： y= 0. 64x＋ 5. 04, r=0. 86, P〈0. 001; APVh： y=0. 63x＋14. 36, r=0.82, P〈0.001; CFVR： y=0.65xq-0.92, r=0.88, P〈0.001）. For CFVR measurements, the mean differences between TTDE and ICD methods were 0. 12±0.39. CFVR in patients with history of hypertension was significantly lower than that in patients without history of hypertension （P〈0.05）. Intravascular ultrasound （IVUS） was performed in 34 patients. Plaque formation was found in LAD by IVUS in 17 （50%） patients. No significant difference in CFVR was found between the patients without plaque formation （3. 11±0. 49） and those with plaque formation （2. 76±0.53, P=0. 056）. It is suggested that TTDE with contrast enhancement provides reliable measurement of APV and CFVR in the distal I.AD. The early stage of atherosclerosis could be detected by IVUS, which may be normal in angiography. CFVR is impaired in patients with history of hypertension compared with that in patients without history of hypertension.

Non-invasive Assessment of Coronary Flow Velocity Reserve: A New Method Using Transthoracic Doppler Echocardiography

Summary: Transthoracic Doppler echocardiography (TTDE) allows noninvasive flow measurement in the distal left anterior descending artery (LAD). The feasibility of detecting coronary flow by contrast-enhanced TTDE with second harmonic technique was assessed, the coronary flow velocity reserve (CFVR) was evaluated in comparison to intracoronary Doppler flow (ICD) analysis and the CFVR after PTCA in LAD was investigated. In 77 (96 %) of 80 patients, CFVR was successfully determined with intravenous adenosine infusion. Doppler signal quality was evaluated in the first 46 patients by use of intravenous Levovist infusion and second harmonic technique. The Doppler flow was not visible in 1 patient only. CFVR determined from TTDE (2.77±0.65) was correlated closely with those from ICD (2.88±0.78) measurements (y=0.73x+0.67, r=0.87, P<0.001). In conclusion, TTDE is a feasible method and provides reliable data on CFVR which can be used for follow-up after PTCA.

Assessment of angiographic coronary slow flow phenomenon with intracoronary ultrasound and doppler flow mapping

In order to study the mechanism of angiographic coronary slow flow phenomenon (SF), intracoronary ultrasound (ICUS) and Doppler (ICD) were performed in 14 patients with angiographic SF phenomenon but with normal angiograms and in 16 patients with normal angiographic coronary flow (NF). A 3.5 F, 20 MHz ultrasound catheter (Boston Scientific) was used for ICUS and a 0.014 inch FloWire (Cardiometrics) was used for ICD. Coronary flow velocity including average peak velocity (APV), maximal peak velocity (MPV) at rest and at hyperemia as well as coronary flow reserve (CFR) were compared in both groups in comparison to the presence or absence of plaque formation based on ICUS. CFR in the SF group (4.2±1.1) was even higher than that of the NF group (3.1±0.6, P<0.001). Department of Cardiology, University GHS Essen, Germany (Ge JB, Simon H, Jeremias A, Liu FQ, Grge G, Haude M, Baumgart D and Erbel R) Significant differences were also found concerning the APV and MPV among both groups (both P <0.001). Plaque formation was found in 7/13 patients with a lumen reduction of 21%±24% in SF group and in 7/16 of the NF group with a lumen reduction of 19%±17%. Comparison of APV, MPV and CFR in SF and NF grups. Comparison of APV, MPV and CFR in SF and NF groups[BHDFG1*2,WK8ZQ1,WK11DW,WK11DWW] SF group NF groupAPV (cm/s) Rest 7.7±2.0 21.1±5.0 * Peak31.7±14.961.3±14.2 *MPV (cm/s) Rest17.4±4.637.0±11.4 * Peak56.8±14.981.8±17.7 *CFR4.2±1.13.1±0.6 # * P<0.001, #P=0.002. Coronary slow flow phenomenon in angiography indicates reduced resting flow velocity without reduction of coronary flow reserve.