Changes In Coronary Flow Velocity Research Articles

Diagnostic value of coronary flow acceleration measured by transesophageal echocardiography in coronary artery bypass graft surgery

Background: Transesophageal echocardiography as a method of intraoperative coronary flow assessment is largely unstudied.Objective: To evaluate the potential of intraoperative transesophageal echocardiography in diagnosing proximal coronary artery stenoses, to reveal the correlation between stenoses found on coronary angiography and coronary flow velocity in the corresponding area measured by intraoperative transesophageal echocardiography, and to study how coronary flow velocity changes before and after coronary artery bypass graft surgery and how it is related to postoperative myocardial injury.Methods: Our prospective cohort study included 186 patients scheduled for coronary artery bypass graft surgery. All the patients underwent intraoperative transesophageal echocardiography: coronary flow velocity was measured in the area of its acceleration (proximal parts of the left coronary artery) before and after the surgery. Troponin I was measured on the first postoperative day.Results: The areas of accelerated coronary flow before the procedure were detected in the left main coronary artery (88 patients, 47.3%), left anterior descending artery (146 patients, 78.5%), and left circumflex artery (28 patients, 15.1%). ROC analysis showed that coronary flow velocity of >73 cm/s in the left main coronary artery and of >91 cm/s in the left circumflex artery was associated with a stenosis of 50% and 70% in the respective arteries measured by coronary angiography. Furthermore, an increase in coronary flow velocity in the left anterior descending artery or its decrease by 4 cm/s after coronary artery bypass graft surgery are predictors of a 10-fold increase in troponin I concentration in the postoperative period.Conclusion: Coronary flow velocity assessment during intraoperative transesophageal echocardiography can offer added value in detecting clinically significant coronary artery stenoses, while assessment of changes in velocity may predict perioperative myocardial injury. Received 16 January 2023. Revised 16 May 2023. Accepted 31 August 2023. Funding: The study did not have sponsorship. Conflict of interest: The authors declare no conflict of interest. Contribution of the authorsConception and study design: S.M. Efremov, M.A. Novikov, A.V. ZagatinaData collection and analysis: S.M. Efremov, M.A. Novikov, A.A. Trofimov, A.V. ZagatinaStatistical analysis: S.M. Efremov, A.A. TrofimovDrafting the article: S.M. Efremov, A.A. TrofimovCritical revision of the article: S.M. Efremov, M.A. Novikov, A.A. Trofimov, D.V. Shmatov, M.S. Kamenskih, A.V. ZagatinaFinal approval of the version to be published: S.M. Efremov, M.A. Novikov, A.A. Trofimov, D.V. Shmatov, M.S. Kamenskih, A.V. Zagatina

Intraoperative transesophageal assessment of coronary artery flow can predict 5 type myocardial infarction

Abstract Background Stenosis of a coronary artery results in an increase in flow velocity in the pathologic segment. Effective grafting should decrease the stenotic native coronary velocity according to hemodynamic law. The range of decreased velocity before and after cardiac surgery can hypothetically reflect the effectiveness of a graft. The aim of the study is to determine if measuring coronary flow velocity changes during coronary artery bypass grafting (CABG) can predict intraoperative myocardial infarction. Methods One hundred sixty-six (166) consecutive patients (121 men, 64±9 years old) referred for cardiac surgery, were prospectively included in the study. A standard basic perioperative transesophageal echocardiography (TEE) examination was performed with additional scans of the left main, left anterior descending (LAD), and circumflex (LCx) arteries' proximal segments. Measurements of coronary flow velocities were performed before and after grafting in the same sites of the arteries. The maximal value of cardiac troponin I (cTnI) after CABG and the additive criteria were accounted for in the analysis as it is described in the expert consensus document for Type 5 myocardial infarction (MI) definition. Results One hundred sixty-three patients (98%) had arterial hypertension, 28 patients (17%) had diabetes mellitus, 35 patients (21%) were currently smokers. The feasibility of coronary flow assessment during cardiac operations was 95%. Before grafting, the mean velocity in the left main artery was 91±49 cm/s, in LAD 101±35 cm/s, and in LCx 117±49 cm/s. There was a significant correlation between changes in coronary flow velocities during operation and the value of cTnI (R=0.34, p<0.0001). Ten patients met the criteria for Type 5 MI. There were no differences in age, body mass index, number of coronary arteries with stenoses, frequency of prior MI, ejection fraction or coronary flow velocity before surgery in patients with and without Type 5 MI. The group of patients with Type 5 MI had an increase in native artery velocities during surgery in comparison with patients without MI, who had a significant decrease in coronary flow velocity after grafting (30±48 vs. −10±30 cm/s; p<0.0006). Increases in native coronary velocities greater than 3 cm/s predicted Type 5 MI with 81% accuracy (sensitivity 88%, specificity 70%). Conclusion Coronary flow velocity assessment during cardiac surgery could predict an elevation of cardiac troponins and Type 5 MI. Funding Acknowledgement Type of funding source: None

P1564 Changes in coronary flow velocity measuring during coronary bypass grafting can predict elevation of cardiac troponin

Abstract Background Stenosis of a coronary artery results in an increase in flow velocity in the pathologic segment. Effective grafting should decrease the stenotic native coronary velocity according to a hemodynamic law. The range of decreased velocity can hypothetically reflect the effectiveness of a graft. Grafting effect insufficiencies often cause elevations in periprocedural cardiac troponin (cTn) elevation. The aim of the study is to determine, if measuring coronary flow velocity changes during coronary artery bypass grafting (CABG) can predict further cTn elevation. Methods and results Consecutive 68 patients (48 men, 64 ± 9 years old), who were referred for CABG, were included into the study. A standard basic perioperative transesophageal echocardiography (TEE) examination was performed with additional scans of the left main, left anterior descending (LAD), and circumflex (LCx) arteries’ proximal segments. Measurements of coronary flow velocities was performed before and after grafting in the same sites of the arteries. The maximal value of cTnI within 48 hours after CABG was accounted for in the analysis. All patients had arterial hypertension, 15 patients (22%) had diabetes mellitus, 12 patients (18%) was current smokers. Forty-one patients (60%) had prior myocardial infarctions, 18 persons (26%) had previous coronary stenting. The ejection fraction before the operation was 56 ± 13%. Before grafting the mean velocity in the left main artery was 79 cm/s (25th-75th quartile, 42-111), in LAD 98 cm/s (25th-75th quartile, 71-125), and in LCx 116 cm/s (25th-75th quartile, 68-156). There was a strong significant correlation between changes in coronary flow velocities and the value of cTnI (R = 0.56, p < 0.0004). The patients with and without significant elevations in cTnI had differences in coronary velocity changes before and after grafting (p < 0.009). Patients with elevated cTnI in more than 5 times, had, on average, an increase in the velocities for native arteries of 21 ± 19 cm/s. Conclusion Coronary flow velocity assessment during CABG could predict an elevation of cardiac troponins after cardiac surgery. Abstract P1564 Figure.

055 RELIABILITY OF RESTING CORONARY HAEMODYNAMICS WHEN REPEATED AFTER 6 MONTHS

Background Vasodilator-free indices of coronary stenosis severity require stability of resting coronary hemodynamics. It is unknown whether resting hemodynamics are sufficiently reproducible to be reliable over an extended period. We evaluate the long-term stability of resting and hyperaemic intracoronary pressure and flow velocity measurements over a 6-month period. Methods 17 patients (mean age 55±12), with 18 anatomically mild-to-moderate lesions (17 in the mid-left anterior descending artery and 1 circumflex artery) had invasive simultaneous pressure and flow velocity measurements made at rest and during intravenous adenosine infusion (140 µg/kg/min). Measurements were repeated after 6 months at the same vessel location. Changes in coronary flow velocity and microcirculatory resistance were compared using Student t test and the F test. Results Mean flow velocity at rest was similar at baseline and 6 months (22.2±8.5 cm/s vs 21.6±8.5 cm/s, p=0.78); hyperaemic mean flow (43.3±14.1 cm/s vs 46.5±11.5 cm/s, p=0.47) similarly did not significantly change. The mean change between baseline and 6 months was 4% and 17% for resting and hyperaemic flow respectively and this was not significantly different (p=0.27). Peak coronary flow velocity was also similar at both time points at rest (53.5±27.2 cm/s vs 46.9±20.3 cm/s, p=0.38) and hyperaemia (88.0±22.5 cm/s vs 90.4±24.6 cm/s, p=0.75); the mean change was 3.0% and 9.0% respectively (p=0.50). Microcirculatory resistance measured at rest was unchanged between baseline and 6 months at rest (4.97±2.37 mm Hg/cm.s vs 5.23±2.25 mm Hg/cm.s, p=0.58) and during hyperaemia (1.94±0.72 vs 1.95±0.67, p=0.98). The mean change in resistance was 17.8% at rest and 11.9% for hyperaemia, with no significant difference (p=0.64). Conclusions Coronary flow velocity and microcirculatory resistance when measured over rest or hyperaemia, vary to a similar degree over 6 months. This suggests that coronary haemodynamics during resting conditions are stable, consistent and reproducible in a manner similar to that observed during adenosine-mediated hyperaemia.

Resting Coronary Haemodynamics are Stable and Reproducible When Retested After 6 Months in Patients with Non-obstructive Coronary Artery Disease

Background: Vasodilator-free indices of coronary stenosis severity require stability of resting coronary hemodynamics. It is unknown whether resting hemodynamics are sufficiently reproducible to be reliable over an extended period. We evaluate the long-term stability of resting and hyperemic intracoronary pressure and flow velocity measurements over a 6-month period. Methods: 17 patients (mean age 55+/-12), with 18 anatomically mild-to-moderate lesions (17 in the mid-left anterior descending artery and 1 circumflex artery) had invasive simultaneous pressure and flow velocity measurements made at rest and during intravenous adenosine infusion (140mcg/kg/min). Measurements were repeated after 6 months at the same vessel location. Changes in coronary flow velocity and microcirculatory resistance were compared using Students T-test and the F-test. Results: Mean flow velocity at rest was similar at baseline and 6 months (22.2+/-8.5cm/s vs 21.6+/-8.5cm/s, p1⁄40.78); hyperemic mean flow (43.3+/-14.1cm/s vs 46.5+/-11.5cm/s, p1⁄40.47) similarly did not significantly change. The mean change between baseline and 6 months was 4% and 17% for resting and hyperemic flow respectively and this was not significantly different (p1⁄40.27). Peak coronary flow velocity was also similar at both time points at rest (53.5+/-27.2cm/s vs 46.9+/-20.3cm/s, p1⁄40.38) and hyperemia (88.0+/-22.5cm/s vs 90.4+/-24.6cm/s, p1⁄40.75); the mean change was 3.0% and 9.0% respectively (p1⁄40.50). Microcirculatory resistance measured at rest was unchanged between baseline and 6 months at rest (4.97+/-2.37mmHg/cm.s vs 5.23+/-2.25mmHg/cm.s, p1⁄40.58) and during hyperemia (1.94+/-0.72 vs

Proximal Coronary Hemodynamic Changes Evaluated by Intracardiac Echocardiography during Myocardial Ischemia and Reperfusion in a Canine Model

The purpose of this study was to assess whether the dynamic changes in coronary flow velocity and coronary flow velocity reserve (CFVR) by intracardiac echocardiography (ICE) within proximal coronary arteries are related to myocardial perfusion status and infarct size in a myocardial ischemia-reperfusion injury model. In 14 dogs, left anterior descending coronary artery (LAD) was ligated for 2 hours followed by 2 hours reperfusion. Coronary flow velocity was obtained by ICE within coronary arteries at baseline, and at the end of both occlusion and reperfusion period. The CFVR was calculated as the ratio of hyperemic to resting peak diastolic velocity (PDV). Myocardial perfusion was evaluated by real time myocardial contrast echocardiography (MCE). The infarct area was detected by triphenyltetrazolium chloride (TTC) staining and expressed as the percentage of the whole left ventricular (LV) area. CFVR significantly decreased both in proximal LAD and left circumflex (LCx) artery at the end of occlusion, and did not recover at the end of reperfusion. However, no significant difference in flow parameters was observed between dogs with myocardial perfusion defect and those without. CFVR in LAD at the end of reperfusion did not correlate with the infarct size (r =-0.182, P = NS) either. Decreased CFVR detected by ICE occurs both in ischemic and in nonischemic proximal arteries during myocardial ischemia and early stage of reperfusion. This change in CFVR has poor correlation with the extent of microvascular impairment and cannot be used to predict infarct size.

Coronary Flow Velocity Changes in Response to Hypercapnia: Assessment by Transthoracic Doppler Echocardiography

The effects of hypercapnia on coronary arteries in human beings are not known. We used transthoracic Doppler echocardiography to evaluate coronary blood flow velocity (CFV) changes in response to hypercapnia in healthy adults. Twenty adults underwent transthoracic Doppler echocardiography of the left anterior descending coronary artery while breathing room air, 40% fraction of inspired oxygen, and 40% fraction of inspired oxygen with carbon dioxide supplemented to end-tidal tensions of +5, +7.5, and +10 mm Hg above baseline. Mean (SD) diastolic peak CFV values for these conditions were 23.1 (9.1), 23.0 (9.0), 25.5 (9.3), 27.9 (11.5), and 31.5 (13.0) cm/s, respectively. Significant overall differences between conditions (P < .001) and progressive levels of hypercapnia (P < or = .01) were observed. CFV increases remained significant after adjusting for increases in cardiac output (P = .038). CFV increases with hypercapnia. This is the first report of human coronary artery flow responses to hypercapnia. Transthoracic Doppler echocardiography methodology is feasible for measuring CFV and the effects of hypercapnia on the coronary circulation.

Relation between changes in coronary flow velocity and in wall motion for assessing contractile reserve during dobutamine stress echocardiography

The purpose of this study was to determine the relationship between coronary flow velocity (CFV) measured by transthoracic Doppler echocardiography (TTDE) and wall motion during dobutamine stress echocardiography (DSE) in patients with resting wall motion abnormalities (WMAs). One hundred fifty patients with resting WMA in the left anterior descending coronary artery (LAD) territory underwent CFV recording in the distal LAD by TTDE during contrast-enhanced DSE. Regional wall motion, CFV, and CFV ratio, defined as a ratio of CFV at each stage of dobutamine stress to basal CFV, were obtained. Patients were divided into 4 groups (sustained improvement, biphasic response, worsening response, and no change). CFV was successfully recorded in 129 patients during DSE (86%). The mean value of basal CFV did not differ among the 4 groups. Although CFV ratio during DSE progressively increased in patients with sustained improvement, this increase was blunted with biphasic response and almost lost with worsening or no change response ( P < .001, ANOVA). CFV ratio at peak stress was significantly higher in patients with sustained improvement (2.73 ± 0.69) than that with the other 3 groups ( P < .001). The value with biphasic response (1.68 ± 0.56) was also higher than that with worsening (0.98 ± 0.15, P < .005) and no change (1.28 ± 0.38, P < .08). The simultaneous assessment of CFV and function in the LAD territory is feasible, and flow and function are closely correlated. TTDE provides flow information that may complement conventional echocardiographic assessment of myocardial viability. (J Am Soc Echocardiogr 2002;15:1290-6.)

Verapamil improves the pacing-induced vasodilatation in symptomatic patients with hypertrophic cardiomyopathy

The purpose of the study was to assess the effect of verapamil on the response of diastolic coronary flow velocity and coronary vascular resistance to pacing in symptomatic patients with hypertrophic cardiomyopathy. In 14 patients with hypertrophic cardiomyopathy, the coronary flow velocity was detected in the left anterior descending coronary artery using transthoracic Doppler echocardiography. The peak diastolic coronary flow velocity and coronary vascular resistance was measured at baseline and during pacing. Changes of these parameters induced by the pacing (expressed as the percentage of baseline values) were compared on verapamil treatment and after verapamil withdrawal. The same measurements were obtained in ten control subjects. The results show that, in hypertrophic cardiomyopathy patients, increase in coronary flow velocity during pacing was significantly higher on than off verapamil therapy (64.8±32.5 vs. 41.1±21.3%, P<0.05). In control subjects, pacing-induced increase in coronary flow velocity was comparable to changes in coronary flow velocity in hypertrophic cardiomyopathy patients receiving verapamil (80.2±18.4 vs. 64.8±32.5%, P>0.05). After verapamil withdrawal in hypertrophic cardiomyopathy patients, coronary flow velocity increase during pacing was significantly lower than in control subjects (41.1±21.3 vs. 80.2±18.4%, P<0.05). During pacing the coronary vascular resistance decreased more on verapamil than after drug withdrawal (−34.7±11.7 vs. −24.6±12.9%, P<0.05). In control subjects the coronary vascular resistance decreased during pacing −38.6±6.3% to similar extent as in hypertrophic cardiomyopathy patients on verapamil. We can conclude that endothelium-dependent vasodilatation during pacing was impaired in symptomatic patients with hypertrophic cardiomyopathy. Verapamil treatment was able to restore adequate vasodilator response to pacing stress.

Coronary flow velocity response to adenosine characterizes coronary microvascular function in women with chest pain and no obstructive coronary disease: Results from the pilot phase of the Women’s Ischemia Syndrome Evaluation (WISE) Study

OBJECTIVESWe sought to develop and validate a definition of coronary microvascular dysfunction in women with chest pain and no significant epicardial obstruction based on adenosine-induced changes in coronary flow velocity (i.e., coronary velocity reserve).BACKGROUNDChest pain is frequently not caused by fixed obstructive coronary artery disease (CAD) of large vessels in women. Coronary microvascular dysfunction is an alternative mechanism of chest pain that is more prevalent in women and is associated with attenuated coronary volumetric flow augmentation in response to hyperemic stimuli (i.e., abnormal coronary flow reserve). However, traditional assessment of coronary volumetric flow reserve is time-consuming and not uniformly available.METHODSAs part of the Women’s Ischemia Syndrome Evaluation (WISE) study, 48 women with chest pain and normal coronary arteries or minimal coronary luminal irregularities (mean stenosis = 7%) underwent assessment of coronary blood flow reserve and coronary flow velocity reserve. Blood flow responses to intracoronary adenosine were measured using intracoronary Doppler ultrasonography and quantitative angiography.RESULTSCoronary volumetric flow reserve correlated with coronary velocity reserve (Pearson correlation = 0.87, p < 0.001). In 29 (60%) women with abnormal coronary microcirculation (mean coronary flow reserve = 1.84), adenosine increased coronary velocity by 89% (p < 0.001) but did not change coronary cross-sectional area. In 19 (40%) women with normal microcirculation (mean flow reserve = 3.24), adenosine increased coronary velocity and area by 179% (p < 0.001) and 17% (p < 0.001), respectively. A coronary velocity reserve threshold of 2.24 provided the best balance between sensitivity and specificity (90% and 89%, respectively) for the diagnosis of microvascular dysfunction. In addition, failure of the epicardial coronary to dilate at least 9% was found to be a sensitive (79%) and specific (79%) surrogate marker of microvascular dysfunction.CONCLUSIONSCoronary flow velocity response to intracoronary adenosine characterizes coronary microvascular function in women with chest pain in the absence of obstructive CAD. Attenuated epicardial coronary dilation response to adenosine may be a surrogate marker of microvascular dysfunction in women with chest pain and no obstructive CAD.

Ergonovine-Induced Alterations in Coronary Flow Velocity Preceding Onset of Occlusive Spasm in Patients Without Significant Coronary Artery Stenoses

This study examined serial changes in coronary flow velocity to elucidate the dynamic change of coronary circulation during coronary spasm. Twenty patients with variant angina and 27 control patients were studied. Coronary flow velocity was monitored using a Doppler guidewire following intracoronary ergonovine administration. In the control group, diastolic flow velocity either did not change or increased slightly in response to ergonovine. However, in patients with variant angina, 2 patterns of flow velocity alterations were observed. In the first pattern, flow initially increased and then suddenly decreased (16 of 20 patients). In the second pattern, flow gradually decreased (3 of 20 patients). In the remaining patient, the coronary flow alteration could not be detected because of branch spasm. When abnormally high flow velocity was defined as a 100% increase in flow after ergonovine administration within 1 minute, and abnormally low flow velocity was defined as a 50% decrease in flow to diagnose variant angina, sensitivities of 35%, 75%, and 85% were noted if flow was measured 1.0, 2.0, and 3.0 minutes after ergonovine administration, respectively. These abnormal flow velocities were observed before ischemic ST changes appeared. In conclusion, in patients with variant angina, characteristic serial changes in coronary flow velocity occur before occlusive spasm. Variant angina may be diagnosed earlier by monitoring flow velocity rather than by monitoring for ischemic electrocardiographic changes.

Coronary vein flow velocity changes during transluminal balloon angioplasty: a study using the Doppler guide wire.

The coronary flow velocity changes in the great cardiac and middle cardiac veins, induced by intracoronary administration of nitroglycerine, adenosine, and during percutaneous transluminal coronary angioplasty, were evaluated in 12 patients with significant coronary stenoses, using the Doppler wire (Flowire). Optimal spectral signals of the time-averaged peak flow velocity were obtained in 10 patients. Nitroglycerine produced no significant flow velocity changes (P = 0.13). Adenosine caused a significant augmentation of flow velocity compared to baseline (P = 0.003). During balloon inflation, venous flow velocity decreased (P = 0.007); however, the venous outflow did not cease. A pronounced venous hyperemic response, following balloon deflation, was also documented. The utility of continuous vein flow velocity monitoring with the Flowire, during high-risk and complicated coronary interventions remains to be elucidated.

Coronary vein flow velocity changes during transluminal balloon angioplasty: A study using the doppler guide wire

The coronary flow velocity changes in the great cardiac and middle cardiac veins, induced by intracoronary administration of nitroglycerine, adenosine, and during percutaneous transluminal coronary angioplasty, were evaluated in 12 patients with significant coronary stenoses, using the Doppler wire (Flowire). Optimal spectral signals of the time-averaged peak flow velocity were obtained in 10 patients. Nitroglycerine produced no significant flow velocity changes (P = 0.13). Adenosine caused a significant augmentation of flow velocity compared to baseline (P = 0.003). During balloon inflation, venous flow velocity decreased (P - 0.007); however, the venous outflow did not cease. A pronounced venous hyperemic response, following balloon deflation, was also documented. The utility of continuous vein flow velocity monitoring with the Flowire, during high-risk and complicated coronary interventions remains to be elucidated. Cathet Cardiovasc Diagn 40:85–91, 1997. © 1997 Wiley-Liss, Inc.

Coronary flow velocity changes after intravenous dipyridamole infusion: Measurements using intravascular Doppler guide wire a documentation of flow inhomogeneity

This study assessed changes in coronary flow velocity measured distal to a significant stenosis of the left anterior descending coronary artery and at the adjacent normal left circumflex coronary artery, produced by intravenous administration of dipyridamole, in patients undergoing coronary angioplasty with a documented perfusion defect on dipyridamole-thallium-201 scintigraphy. Significant flow inhomogeneity is believed to develop during coronary vasodilation induced by dipyridamole, causing a defect in the thallium-201 scintigram. The recently developed intracoronary Doppler guide wire permits assessment of flow velocity variables in normal and stenotic arteries. In 17 patients with stable angina we studied changes in time-averaged peak velocity and the diastolic/systolic velocity ratio simultaneously using two 0.014-in. (0.36-mm) Doppler guide wires at baseline and after 4 min of dipyridamole infusion (0.56 mg/kg body weight). Coronary flow velocity reserve and relative flow reserve were correlated with the degree of stenosis on coronary angiography and quantitative analysis of thallium-201 images. No changes in distal flow velocity was observed in the stenotic vessel (5.5 +/- 33.7% [mean +/- SD]), in contrast to a significant increase observed in the adjacent normal vessel (162.4 +/- 39.8%). Poststenotic coronary flow velocity reserve correlated with percent lumen diameter stenosis (r = -0.66, p < 0.05). A correlation was also observed between the relative flow reserve/thallium-201 relative perfusion ratio (r = 0.90, p < 0.001). To our knowledge, these findings represent the first direct proof of dipyridamole-induced flow inhomogeneity producing a perfusion defect on thallium-201 imaging. The degree of inhomogeneity is related to the extent of the perfusion defect.

Noninvasive assessment of coronary flow dynamics before and after coronary angioplasty using transesophageal Doppler

Recent invasive studies using intracoronary Doppler catheters or guide wires reported improved coronary flow dynamics after successful percutaneous transluminal coronary angioplasty. Transesophageal Doppler enables the measurement of coronary flow velocities within the left anterior descending artery. The present study was designed to test: (1) whether transesophageal Doppler may detect coronary flow velocity changes in patients undergoing angioplasty for left anterior descending artery stenosis, and (2) whether this technique may help to evaluate non-invasively the results of the procedure. Twenty-three patients undergoing angioplasty of the left anterior descending artery were studied by transesophageal Doppler before and ≤24 hours after the interventional procedure. Coronary flow velocities were measured in the proximal part of the left anterior descending artery with the use of pulsed Doppler guided by color flow imaging. The degree of stenosis was measured by computerized quantitative coronary arteriography. Coronary flow velocity signals were successfully obtained in 19 of 23 patients (83%). In 16 successful angioplasty procedures, peak diastolic velocity increased from 37 ± 14 cm/s before angioplasty to 51 ± 16 cm/s after (p = 0.0001). In the 3 patients in whom angioplasty was unsuccessful, transesophageal Doppler showed no significant increase in peak diastolic coronary flow velocity. In a total of 19 angioplasty procedures, a good linear relation was found between the percent changes in coronary flow diastolic velocity and the reduction in the degree of stenosis (r = 0.85; p = 0.0001). All patients with >20% increase in peak diastolic velocity had >40% stenosis reduction. Thus, in patients with stenosis of the left anterior descending artery, transesophageal Doppler shows improvement in coronary flow pattern after successful angioplasty. This method may be useful for noninvasive evaluation of angioplasty results in these patients.