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Coronary Flow Reserve (coronary + flow_reserve)

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Medical Sciences	100%

Selected Abstracts

Relationship between Strain Rate Imaging and Coronary Flow Reserve in Assessing Myocardial Viability after Acute Myocardial Infarction

ECHOCARDIOGRAPHY, Issue 8 2010
Ph.D., Seong-Mi Park M.D.
Objectives: To evaluate the relationship between strain rate (SR) imaging and coronary flow reserve (CFR) in assessing viability of akinetic myocardium after acute myocardial infarction (MI). Methods: Forty patients with acute first ST-elevation MI were analyzed. SR imaging and CFR by intracoronary flow measurement were obtained on the same day, 3,5 days after primary percutaneous coronary intervention. Viability of the akinetic myocardium was determined on 6-week echocardiography. Results: Systolic SR (SRs, ,0.42 ± 0.10 vs. ,0.35 ± 0.11 per second, P = 0.03), early diastolic SR (SRe, 0.68 ± 0.31 vs. 0.41 ± 0.22 per second, P = 0.003), and systolic strain (Ss, ,5.9 ± 3.4 vs. ,2.5 ± 4.0%, P = 0.04) were greater in akinetic, but viable myocardium of 21 patients than in akinetic and nonviable myocardium of 19 patients. CFR was also higher in patients with akinetic, but viable myocardium (2.0 ± 0.5 vs. 1.5 ± 0.5, P < 0.001). SRs, SRe, and Ss were significantly related to CFR (r =,0.50, r = 0.58, r =,0.56, respectively, all P , 0.001) and SRe was most related to CFR (P < 0.001). The sensitivity and specificity to predict myocardial viability were 85.7% and 68.4% for CFR (cutoff = 1.75), and 90.5% and 57.9% for SRe (cutoff = 0.37 per second), respectively. Conclusions: The degree of myocardial deformation determined by SR imaging was related to the degree of microvascular integrity determined by CFR, and can be used as a noninvasive method to predict myocardial viability after acute MI. (Echocardiography 2010;27:977-984) [source]

Noninvasive Assessment of Coronary Flow Reserve in the Left Anterior Descending Artery by Transthoracic Echocardiography before and after Stenting

ECHOCARDIOGRAPHY, Issue 8 2007
Elie Chammas M.D., F.E.S.C.
Background: Noninvasive assessment of coronary flow reserve in the left anterior descending artery (LAD) by transthoracic Doppler echocardiography (TTDE) has been already validated as a new method for determining the degree of stenosis over the proximal flow. Objectives: The aim of the study is to determine, by TTDE, the feasibility and the value of the coronary flow reserve (CFR) (defined as the maximal increase in coronary blood flow above its basal pressure for a given perfusion pressure when coronary circulation is maximally dilated) in the mid-to-distal LAD before and after percutaneous angioplasty and to demonstrate the early recovery of microvascular tone immediately after stenting. Methods: The study population consisted of 36 patients with significant isolated LAD stenosis (70,90%) identified by coronary angiography. CFR was recorded in the mid-to-distal LAD at rest and during hyperemia obtained after adenosine intravenous infusion before and after stenting. Results: Adequate visualization of the LAD was obtained in 25 out of 36 patients (70%). At rest the mean CFR was 1.5132 ± 0.33 (1.1,2.58). However, after stenting the mean CFR was significantly higher: 2.18 ± 0.55 (1.3,3.8), with P <0.01. Conclusions: CFR can be easily determined by TTE in approximately 70% of patients. Noninvasive Doppler echocardiography shows impaired CFR in patients with LAD disease. After stenting CFR is restored, demonstrating early recovery of microvascular tone. These results are comparable to those published in the same conditions. Larger series with a long-term follow-up may allow identifying patients at high risk for restenosis after stenting. [source]

Coronary Flow Reserve by Transthoracic Echocardiography Predicts Epicardial Intimal Thickening in Cardiac Allograft Vasculopathy

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 7 2010
F. Tona
Cardiac allograft vasculopathy (CAV) is the leading cause of morbidity and mortality in heart transplantation (HT). We sought to investigate the role of coronary flow reserve (CFR) by contrast-enhanced transthoracic echocardiography (CE-TTE) in CAV diagnosis. CAV was defined as maximal intimal thickness (MIT) assessed by intravascular ultrasound (IVUS) ,0.5 mm. CFR was assessed in the left anterior descending coronary artery in 22 HT recipients at 6 ± 4 years post-HT. CAV was diagnosed in 10 patients (group A), 12 had normal coronaries (group B). The mean MIT was 0.7 ± 0.1 mm (range 0.03,1.8). MIT was higher in group A (1.16 ± 0.3 mm vs. 0.34 ± 0.07 mm, p < 0.0001). CFR was 3.1 ± 0.8 in all patients and lower in group A (2.5 ± 0.6 vs. 3.7 ± 0.3, p < 0.0001). CFR was inversely related with MIT (r =,0.774, p < 0.0001). A cut point of ,2.9, identified as optimal by receiver operating characteristics analysis was 100% specific and 80% sensitive (PPV = 100%, NPV = 89%, Accuracy = 91%). CFR assessment by CE-TTE is a novel noninvasive diagnostic tool in the detection of CAV defined as MIT ,0.5 mm. CFR by CE-TTE may reduce the need for routine IVUS in HT. [source]

Coronary Flow Reserve by Contrast-Enhanced Echocardiography: A New Noninvasive Diagnostic Tool for Cardiac Allograft Vasculopathy

AMERICAN JOURNAL OF TRANSPLANTATION, Issue 5p1 2006
F. Tona
Noninvasive tests have proven unsatisfactory in cardiac allograft vasculopathy (CAV) diagnosis. We assessed coronary flow reserve (CFR) by contrast-enhanced transthoracic echocardiography (CE-TTE) in heart transplantation (HT). CFR was assessed in the left anterior descending coronary artery in 73 HT recipients (59 male, aged 50 ± 12 years at HT), at 8 ± 4.5 years post-HT. CFR measurements were taken blindly from coronary angiographies. CFR cut points were the standard value of ,2 and those defined by receiver operating characteristics (ROC) curve analysis. CFR was lower in patients with CAV (2.3 ± 0.7 vs. 3.2 ± 0.5, p < 0.0001). The ,2 cut point was 100% specific and 38% sensitive. The ,2.7 cut point, optimal by ROC analysis, was 87% specific and 82% sensitive. Accuracy rose from 71% with the standard ,2 cut point to 85% with the optimal cut point of ,2.7. CFR by CE-TTE may offer promise as a novel, easily repeatable and accurate noninvasive tool in CAV detection. However, further longitudinal studies in larger patient cohorts are warranted before widespread adoption can be advocated. [source]

Impairment of Coronary Microvascular Function in Patients with Neurally Mediated Syncope

PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 2p1 2003
JAW-WEN CHEN
CHEN, J.-W., et al.: Impairment of Coronary Microvascular Function in Patients with Neurally Mediated Syncope.Recent evidence suggests that myocardial ischemia may occur in patients with neurally mediated syncope and normal coronary angiograms. This study was conducted to evaluate if coronary microvascular function is impaired in such patients. Coronary hemodynamic studies and head-up tilt table tests (HUTs) were performed on 30 consecutive patients with normal coronary angiograms and recurrent syncope. Another ten subjects with atypical chest pain and no evidence of myocardial ischemia or syncope served as a control. Great cardiac vein flow (GCVF) and coronary sinus flow (CSF) were measured by the thermodilution method at baseline and after dipyridamole infusion (0.56 mg/kg IV for 4 minutes). Coronary flow reserve (CFR), derived from CSF and GCVF, was significantly lower in the 15 patients with positive HUT than in the other 15 patients with negative HUT (1.75 ± 0.48vs2.64 ± 0.8, P < 0.01and2.29 ± 0.45vs3.07 ± 0.63, P < 0.01, respectively). Ischemic-like ECG was noted during treadmill exercise test in 40% of the former and in 7% of the latter group(P = 0.01). There was no significant difference in CFR between patients with negative HUT and control subjects. Coronary microvascular function was impaired in syncopal patients with positive HUT and relatively preserved in those with negative HUT, suggesting the possible linkage between coronary microvascular dysfunction and the development of neurally mediated syncope. (PACE 2003; 26[Pt. I]:605,612) [source]

Effect of Chronic Sustained-Release Dipyridamole on Myocardial Blood Flow and Left Ventricular Function in Patients With Ischemic Cardiomyopathy

CONGESTIVE HEART FAILURE, Issue 3 2007
Mateen Akhtar MD
Dipyridamole increases adenosine levels and augments coronary collateralization in patients with coronary ischemia. This pilot study tested whether a 6-month course of sustained-release dipyridamole/aspirin improves coronary flow reserve and left ventricular systolic function in patients with ischemic cardiomyopathy. Six outpatients with coronary artery disease and left ventricular ejection fraction (LVEF) <40% were treated with sustained-release dipyridamole 200 mg/aspirin 25 mg twice daily for 6 months. Myocardial function and perfusion, including coronary sinus flow at rest and during intravenous dipyridamole-induced hyperemia, were measured using velocity-encoded cine magnetic resonance stress perfusion studies at baseline, 3 months, and 6 months. There was no change in heart failure or angina class at 6 months. LVEF increased by 39%±64% (31.0%±13.3% at baseline vs 38.3%±10.7% at 6 months; P=.01), hyperemic coronary sinus flow increased more than 2-fold (219.6±121.3 mL/min vs 509.4±349.3 mL/min; P=.01), and stress-induced relative myocardial perfusion increased by 35%±13% (9.4%±3.4% vs 13.9%±8.5%; P=.004). Sustained-release dipyridamole improved hyperemic myocardial blood flow and left ventricular systolic function in patients with ischemic cardiomyopathy. [source]

Relationship between Strain Rate Imaging and Coronary Flow Reserve in Assessing Myocardial Viability after Acute Myocardial Infarction

Transthoracic Doppler Echocardiographic Coronary Flow Imaging in Identification of Left Anterior Descending Coronary Artery Stenosis in Patients with Left Bundle Branch Block

ECHOCARDIOGRAPHY, Issue 10 2008
Ozer Soylu M.D.
Background: Conventional noninvasive methods have well-known limitations for the detection of coronary artery disease (CAD) in patients with left bundle branch block (LBBB). However, advancements in Doppler echocardiography permit transthoracic imaging of coronary flow velocities (CFV) and measurement of coronary flow reserve (CFR). Our aim was to evaluate the diagnostic value of transthoracic CFR measurements for detection of significant left anterior descending (LAD) stenosis in patients with LBBB and compare it to that of myocardial perfusion scintigraphy (MPS). Methods: Simultaneous transthoracic CFR measurements and MPS were analyzed in 44 consecutive patients with suspected CAD and permanent LBBB. Typical diastolic predominant phasic CFV Doppler spectra of distal LAD were obtained at rest and during a two-step (0.56,0.84 mg/kg) dipyridamole infusion protocol. CFR was defined as the ratio of peak hyperemic velocities to the baseline values. A reversible perfusion defect at LAD territory was accepted as a positive scintigraphy finding for significant LAD stenosis. A coronary angiography was performed within 5 days of the CFR studies. Results: The hyperemic diastolic peak velocity (44 ± 9 cm/sec vs 62 ± 2 cm/sec; P=0.01) and diastolic CFR (1.38 ± 0.17 vs 1.93 ± 0.3; P=0.001) were significantly lower in patients with LAD stenosis compared to those without LAD stenosis. The diastolic CFR values of <1.6 yielded a sensitivity of 100% and a specificity of 94% in the identification of significant LAD stenosis. In comparison, MPS detected LAD stenosis with a sensitivity of 100% and a specificity of 29%. Conclusions: CFR measurement by transthoracic Doppler echocardiography is an accurate method that may improve noninvasive identification of LAD stenosis in patients with LBBB. [source]

Noninvasive Assessment of Coronary Flow Reserve in the Left Anterior Descending Artery by Transthoracic Echocardiography before and after Stenting

Coronary Flow Reserve by Transthoracic Echocardiography Predicts Epicardial Intimal Thickening in Cardiac Allograft Vasculopathy

Coronary Flow Reserve by Contrast-Enhanced Echocardiography: A New Noninvasive Diagnostic Tool for Cardiac Allograft Vasculopathy

Altered coronary vasomotor function in young patients with systemic lupus erythematosus

ARTHRITIS & RHEUMATISM, Issue 6 2007
Kumiko Hirata
Objective Accelerated atherosclerosis is an important cause of morbidity and mortality in patients with systemic lupus erythematosus (SLE). Altered coronary microvascular function may act as a marker of changes that predispose to the development of significant coronary vascular disease. The purpose of this study was to compare coronary flow reserve (CFR) in a group of premenopausal women with SLE and a group of age-, sex-, and race-matched healthy control subjects. Methods Coronary flow velocity in 18 premenopausal women with SLE (mean ± SD age 29.4 ± 5.9 years) and 19 matched healthy controls (mean ± SD age 28.2 ± 4.3 years) was assessed by transthoracic Doppler echocardiography after an overnight fast. The CFR was calculated as the ratio of hyperemic to baseline coronary blood flow velocity in the left anterior descending coronary artery. Hyperemia was induced by intravenous administration of adenosine triphosphate. Results The mean ± SD duration of SLE was 8.2 ± 7.2 years (range 0.25,25 years), and the mean ± SD score on the Systemic Lupus Erythematosus Disease Activity Index was 11.0 ± 5.3 (range 4.0,21.0). Adequate recordings of flow velocity in the left anterior descending artery under both conditions were obtained using an ultrasound procedure in all study subjects. CFR was significantly lower in SLE patients as compared with control subjects (mean ± SD 3.4 ± 0.8 versus 4.5 ± 0.5; P < 0.0001). Conclusion These findings provide evidence that coronary vasomotor function is impaired in patients with SLE and support the notion that many of these young patients have subclinical coronary artery disease. [source]

Transient global left ventricular dysfunction in a localized myocardial infarction related to occlusion of the distal left anterior descending artery

CLINICAL CARDIOLOGY, Issue 9 2006
Seong Bo Yoon M.D.
Abstract In some patients with acute myocardial infarction (MI), wall motion in the noninfarcted area declines globally despite localized myocardial damage. In most, an infarct-related lesion is the proximal part of the left anterior descending artery (LAD). Previous studies have reported that hypo-kinesis of remote myocardium may be related to multivessel disease, impaired coronary flow, or coronary flow reserve in nonculprit arteries. This report describes the case of a 53-year-old man who presented with severe global left ventricular (LV) dysfunction after an acute MI associated with distal LAD occlusion. Follow-up echocardiographic examination revealed nearly normalized LV function 5 days after the episode. We discuss a plausible mechanism of dysfunction of noninfarcted myocardium. [source]

Assessment of coronary morphology and flow in a patient with guillain-barré syndrome and st-segment elevation

CLINICAL CARDIOLOGY, Issue 3 2001
Nikolaos Dagres M.D.
Abstract Patients with Guillain-Barré syndrome often have cardiac disturbances as a manifestation of autonomic dysfunction. Such abnormalities consist of arrhythmias and disturbances of heart rate and blood pressure. We report a case of a patient with Guillain-Barré syndrome who developed ST-segment elevation in the inferolateral leads, suggestive of an acute coronary syndrome. Cardiac catheterization revealed angiographically normal coronary arteries. Intracoronary ultrasound was also normal. Intracoronary Doppler flow measurements revealed an elevated baseline coronary flow velocity of up to 41 cm/s and decreased coronary flow reserve, particularly in the left circumflex artery. Myopericarditis as cause of the electrocardiographic changes could be ruled out by echocardiography and endomyocardial biopsy. We postulate that the intracoronary Doppler findings are caused by autonomic dysfunction with decrease of coronary resistance and redistribution of the transmural myocardial blood flow. [source]