Noninvasive measurement of coronary artery blood flow using combined two-dimensional and Doppler echocardiography

Noninvasive measurement of left anterior descending coronary artery flow was attempted in 20 normal subjects and 80 patients with cardiovascular disease (valvular heart disease in 34, ischemic heart disease in 26, cardiomyopathy in 15 and other diseases in 5) using combined two-dimensional and Doppler echocardiography. A tubular structure about 2 mm in diameter containing Doppler flow signals was identified in the anterior interventricular sulcus in 7 (35%) of the normal subjects and 40 (50%) of the patients with cardiovascular disease. The blood flow within the tubular structure exhibited a biphasic flow pattern, consisting of systolic and diastolic phases with higher velocity during diastole. The highest velocities were observed in early diastole and, in several cases, a small peak was detected during the atrial contraction phase. On the basis of its spatial orientation and characteristic flow pattern, the tubular structure was identified as the midportion of the left anterior descending coronary artery. In a number of cases it was difficult to detect the systolic blood flow. Although blood flow was normally directed from the cardiac base to the apex, it was reversed toward the base in the patients with a bypass graft to the left anterior descending coronary artery. In patients with severe aortic insufficiency, however, flow velocity was lower during diastole than during systole and the duration of diastolic flow was reduced, failing to continue to the end of diastole. Flow velocity was high in patients with a bypass graft to the left anterior descending coronary artery, aortic stenosis or hypertrophic cardiomyopathy.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effect of graded coronary stenosis on myocardial blood flow and left ventricular wall motion

Summary The effect of graded coronary stenosis on resting regional myocardial flow and left ventricular (LV) wall motion was studied in 18 anesthetized dogs. The left circumflex coronary artery (LC) was constricted. The degree of LC stenosis and the changes in LV wall motion were determined by cineangiography of the coronary artery and LV. Regional myocardial flow was determined by tracer microspheres (TM), labeled with two different isotopes, Sr⁸⁵, Sc⁴⁶ or Ce¹⁴¹. The first TM₁ and the second TM₂ were infused after LC stenosis, and during a temporary complete LC occlusion respectively. Resting flow in areas with 70% stenosis was reduced, with a greater reduction of subendocardium and posterior papillary muscle, but minimum impairment of LV wall motion. No ST elevation was found. Animals with 80–90% stenosis showed a marked reduction of flow and wall motion, a significant ST-elevation and a delayed antegrade run-off in coronary arteriography.

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Der Einfluß des Stenosegrades auf den myokardialen Ruhefluß und auf die linksventrikuläre Wandbeweglichkeit

Zusammenfassung Der Einfluß des Stenosegrades (Ramus circumflexus der linken Koronararterie) auf den myokardialen Ruhefluß und auf die linksventrikuläre Wandbeweglichkeit wurde an 18 narkotisierten Hunden untersucht. Der Stenosegrad und die Änderungen der Wandbeweglichkeit wurden angiographisch bestimmt. Die regionale Myokarddurchblutung wurde mit tracer microspheres bestimmt, die entweder mit 85-Sr, 46-Sc oder mit 141-Ce markiert waren. Microspheres wurden nach Anlegen der LC-Stenose und während eines temporären LC-Verschlusses injiziert. Der myokardiale Ruhefluß war durch eine 70-%-Stenose bereits reduziert, die Durchblutungsverteilung war inhomogen und im Subendocardium und im posterioren Papillarmuskel deutlich mehr erniedrigt. Die Wandbeweglichkeit war nur minimal eingeschränkt, ST-Streckenhebung wurde nicht beobachtet. Tiere mit einer 80–90-%-Stenose zeigten eine deutliche Erniedrigung des Ruheflusses, die Wandbeweglichkeit war stark eingeschränkt, eine signifikante ST-Streckenhebung wurde beobachtet, und der koronarangiographische antegrade run-off war verzögert.

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With 5 figures and 2 tables

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This study was partly financed by grants from Educational Ministry of Japan.     

经胸超声心动图测定无冠状动脉狭窄的糖尿病患者左心室灌注量可行性的观察

目的 探讨常规经胸超声心动图(TTE)评估糖尿病患者左心室整体灌注功能的可行性及其与糖尿病病程的相关性. 方法 选取经冠状动脉造影证实无冠状动脉狭窄的T2DM患者(T2 DM组)60例和健康对照(NC)者60名.采用多普勒和三维超声心动图测量冠状窦血流和左心室质量(LVM).左心室整体灌注量由冠状窦血流量除以LVM计算所得,并分析其与糖尿病病程的相关性.结果 与NC组比较,T2DM组LVM增加[(154.35±19.44)vs(163.00±17.94)g,P＜0.05],静息时左心室灌注量减少[(6.04±4.77)vs(1.72±0.33) ml/(min·g),P＜0.01].静息时左心室整体灌注量与糖尿病病程呈负相关(r=-0.533,P=0.000). 结论 TTE可有效地检测出经冠状动脉造影证实无冠状动脉狭窄的糖尿病患者在静息时存在冠状动脉微血管功能障碍.糖尿病患者的左心室整体灌注量减少,且与其糖尿病病程呈负相关.     

Real-time dobutamine stress myocardial contrast echocardiography for detecting coronary artery disease: correlating abnormal wall motion and disturbed perfusion

BACKGROUND: Real-time myocardial contrast echocardiography (MCE) makes possible the simultaneous visualization of changes in perfusion imaging and wall motion. OBJECTIVES: To assess the accuracy of real-time MCE for detecting the presence and extent of coronary artery disease (CAD), and to evaluate the correlation between wall motion and myocardial perfusion by visual examination. METHODS: A total of 140 consecutive patients without resting wall motion abnormalities were screened to undergo dobutamine stress MCE with power modulation and coronary angiography. Significant coronary disease was defined by the quantification of over 50% stenosis in a major epicardial vessel. The visual identification of wall motion and myocardial perfusion abnormalities was determined by blind review. RESULTS: Eight patients were excluded due to suboptimal images (feasibility 94.3%). Myocardial contrast enhancement analysis and wall motion analysis were similar in terms of sensitivity (81.2% versus 83.5%, respectively) and specificity (76.5% versus 80.9%, respectively) in detecting the presence of CAD. Myocardial contrast enhancement analysis tended to have a greater sensitivity than wall motion analysis in detecting the ischemic extent over multiple vascular territories among patients with multiple-vessel disease (sensitivity 83.8% versus 71.4% [P=0.09], and abnormal segment length 54.7+/-21.1% versus 48.9+/-24.7% [P=0.03] for myocardial contrast enhancement and wall motion analysis, respectively). There was good concordance between the presence of myocardial ischemia and wall motion abnormality for the segment-by-segment analysis (89.7% agreement, kappa = 0.745). The correlation of the wall motion score and perfusion score at peak stress was also good (r=0.793, P=0.015). CONCLUSIONS: Dobutamine stress MCE with power modulation is similar in sensitivity and specificity to wall motion analysis for detecting the presence of CAD. However, it provides greater sensitivity in evaluating the extent of ischemia in patients with multiple-vessel disease.     

Quantitative analysis of myocardial response to dobutamine by measurement of left ventricular wall motion using omnidirectional M-mode echocardiography

Although dobutamine stress echocardiography is important for assessing cardiac ischemia and viability, analysis of wall motion is qualitatively performed. We quantitatively evaluated left ventricular wall motion using a newly developed omnidirectional M-mode echocardiography that can depict the M-mode at the site of region of interest on the 2-dimensional image in real time, and established its usefulness for analyzing the myocardial response to dobutamine infusion. Dobutamine stress echocardiography with omnidirectional M-mode was performed in 57 patients with coronary lesions. In 38 of these patients, exercise stress single-photon emission computed tomographic thallium scintigraphy (Tl-201 SPECT) was performed. Endocardial excursion of 103 regions was measured from omnidirectional M-mode at baseline, low-dose (6 microg/kg/min), and at peak dose (30 microg/kg/min) dobutamine. A decrease and increase in wall excursion was scored (from -3 to 3) for a changes of every 2 mm, and a quantitative wall motion score (QWMS) was calculated as a summation of the scores from baseline to low dose and from low to peak doses. Quantitative coronary stenosis score (QCSS) was calculated as a summation of stenotic and collateral scores. The stenosis scores were graded as: 1 = 0% to 50%, 2 = 50% to 75%, 3 = 75% to 90%, 4 = 90% to 95%, 5 = 95% to 100%; collateral scores were graded as: -1 = poor collateral, -2 = good collateral. Based on the QWMS at each dose of dobutamine, the serial changes in wall motion were divided into 4 groups: augmented, biphasic, no change, and worsening. The QCSS was clearly different among these groups. QWMS was significantly correlated with QCSS (r = 0.657, p <0.001). The incidence of redistribution in Tl-201 SPECT was high in the region with low score of QWMS. In conclusion, omnidirectional M-mode is useful for quantitatively determining the grade of cardiac ischemia by assessing the serial change of ventricular wall motion during dobutamine infusion.     

Myocardial contrast echocardiography for assessment of myocardial perfusion at rest in a patient with left main coronary artery stenosis

The present case will focus on the potential of hypoperfusion detection with myocardial contrast echocardiography (MCE) using power Doppler harmonic imaging (PDHI). PDHI is normally performed in a triggered mode. Microbubbles were destroyed by the ultrasound energy in the myocardium, and myocardium has to be refilled with microbubbles within the time interval between the ultrasound pulses to obtain repetitive information about perfusion. Using the contrast agent Levovist, however, real-time PDHI also results in myocardial opacification presumably due to perfusion signals of the arteriolar microbubble passage. A 45-year-old woman with typical stress-induced angina was admitted to our department for cardiac catheterization. Prior to the angiography a conventional echocardiogram showed normal left ventricular function. Tissue Doppler, however, demonstrated postsystolic longitudinal shortening of the septal, anterior, and lateral wall regions. Myocardial contrast echocardiography with triggered PDHI showed complete opacification of the myocardium at rest. Using real-time PDHI with Levovist, the septum could not be opacified. The consecutive angiography documented a severe unprotected main coronary artery stenosis. After angioplasty and stent implantation, MCE measurements were repeated. Repetitive intravenous bolus injections of Optison during triggered PDHI showed no differences to the investigation prior to the angioplasty. Using real-time PDHI with Levovist, however, there was a marked difference in comparison to the pre-interventional analysis. A complete opacification of the apical septum was observed. The present case suggests that different MCE techniques can analyze different compartments of the myocardial vasculature in clinical practice. This methodological comparison between triggered and real-time PDHI shows obviously differences in the DI signal detection due to the different microbubble behavior. Clinicians should be aware of the potentials of MCE to improve noninvasive diagnostic procedures in patients with ischemic heart disease.     

Transesophageal Doppler echocardiographic detection of intramyocardial collateral flow to the right coronary artery and changes in the flow to the inferior left ventricular wall immediately after coronary artery bypass grafting

This study examined the feasibility of Doppler transesophageal echocardiography (TEE) to detect collateral flow to the myocardium supplied by the right coronary artery (RCA) in the inferior left ventricular wall. Forty-four patients who underwent elective coronary artery bypass grafting (CABG) were prospectively studied. Presence of collateral flow to the RCA was diagnosed on preoperative angiography using the Rentrop score and by intraoperative Doppler TEE. Agreement of the 2 methods was analyzed by calculating the kappa coefficient. Collateral flow was present on preoperative angiography in 19 patients and absent in 25 patients. Intraoperative TEE detected collateral flow in the inferior wall in 15 patients (79%) with and 3 patients (12%) without angiographic collaterals, resulting in a kappa coefficient for agreement of 0.67 (95% confidence interval 0.45 to 0.90). Baseline collateral flow disappeared after CABG in 12 of 14 patients with grafting of the RCA but persisted in all patients without such grafting. Physiologic flow in the inferior wall was detected by TEE in a total of 27 patients at baseline and in 38 patients after CABG (p = 0.0018); its peak velocity increased after surgery only in the subgroup of patients with grafting of the RCA. In conclusion, these findings indicate that Doppler TEE may detect collateral flow in the inferior left ventricular wall, and that there are typical changes in collateral and physiologic flow after CABG.     

Regional myocardial perfusion and function after coronary bypass surgery: evaluation using handgrip exercise Doppler echocardiography]

To evaluate myocardial perfusion and function of the interventricular septum after coronary artery bypass surgery, 29 patients with internal mammary artery grafts (IMAG) were examined using handgrip exercise Doppler echocardiography. IMAG flow was measured by color flow Doppler. Septal excursion and percent thickening of the interventricular septum during systole were measured as indicators of regional left ventricular function by M-mode echocardiography. Myocardial perfusion was estimated by thallium-201 exercise myocardial scintigraphy using a treadmill. 1. At rest, there were no significant correlations between IMAG flow and septal excursion and percent thickening or myocardial perfusion. 2. After the isometric handgrip exercise test, IMAG flow increased 20.0 +/- 3.9% from at rest, and the percentage of change in IMAG flow correlated significantly with changes in septal excursion (r = 0.63) and percent thickening (r = 0.72). It was found that a response of bypass graft flow to exercise has a correlation with contractility of cardiac muscle. 3. The rate of increase in IMAG flow in patients with normal myocardial scintigraphic findings (31.8 +/- 6.2%) was higher than that in patients with ischemia (15.3 +/- 5.6%) or infarction (15.0 +/- 11.3%). 4. A greater increase of percent thickening was observed in patients with normal exercise myocardial scintigraphic findings. These results suggest that the responses of the bypass graft flow to handgrip exercise may reflect viability and contractility of cardiac muscles perfused by the graft. Thus, exercise Doppler echocardiography is useful for evaluating regional myocardial perfusion and function of the interventricular septum after coronary artery bypass surgery.     

Comparison of two- versus three-dimensional myocardial contrast echocardiography for assessing subendocardial perfusion abnormality after percutaneous coronary intervention in patients with acute myocardial infarction

Myocardial contrast echocardiography (MCE) visualizes myocardial perfusion abnormalities after acute myocardial infarction. However, the limited view of 2-dimensional echocardiography reduces its ability to estimate perfusion abnormalities, especially in the subendocardial region. Three-dimensional echocardiography provides images of the left ventricular endocardium directly. This study was conducted to evaluate the ability of 3-dimensional MCE to assess abnormalities of subendocardial perfusion. Intracoronary 2- and 3-dimensional MCE was performed after primary percutaneous coronary intervention in 47 patients with acute myocardial infarction. Myocardial perfusion within the risk area was evaluated as good, poor, or no reflow on 2-dimensional MCE or as good, poor, or no myocardial opacification in endocardium on 3-dimensional MCE. The 2 methods showed different distributions of perfusion patterns: good, poor, and no reflow on 2-dimensional MCE in 31 (66%), 9 (19%), and 7 (15%) patients and good, poor, and no myocardial opacification in endocardium on 3-dimensional MCE in 17 (36%), 16 (34%), and 14 (20%) patients, respectively. Although only 19 patients (61%) with good reflow on 2-dimensional MCE showed myocardial perfusion grade 3 on angiography, 16 of 17 patients (94%) with good myocardial opacification in endocardium on 3-dimensional MCE showed myocardial perfusion grade 3. Although there were no significant differences in peak creatine kinase among the 3 subsets classified by 2-dimensional MCE, peak creatine kinase showed significant differences not only among the 3 groups but also among the subsets classified by 3-dimensional MCE. Classification by 3-dimensional MCE also predicted regional wall motion after 4.6 +/- 2.7 months, with significant differences between each pair of groups, whereas there was significant overlap of these values between the group with poor reflow and other 2 groups by 2-dimensional MCE. In conclusion, 3-dimensional MCE is a feasible way to assess subendocardial perfusion and predicts infarct size and functional recovery more precisely than 2-dimensional MCE.     

Systolic wall stress may affect the intramural coronary blood flow velocity in myocardial hypertrophy, independently on the left ventricular mass

AIM: We sought to evaluate the relationship between left ventricular systolic wall stress (LV-SWS) and coronary artery blood flow velocity in patients with LV hypertrophy (LVH). METHODS AND RESULTS: The study population comprised 38 patients, aged 66.7 +/- 12.7, who were divided into two groups based on the LV-SWS median value. Group A included 19 patients at "low-stress" (92.0 +/- 18.0 mmHg/cm2) and group B other 19 patients at "high-stress" (134.2 +/- 32.3 mmHg/cm2) (P < 0.002). Coronary blood flow velocities were measured both in the left anterior descending (LAD) and in the intramural (IM) arteries. There were no significant between-group differences in the main clinical and echocardiographic parameters. Diastolic velocity in the LAD was also comparable, while it was higher in the IM arterioles of patients from group B than from group A (peak velocity 110.9 +/- 35.2 cm/s vs 92.0 +/- 29.4 cm/s, P < 0.02; mean velocity 78.6 +/- 28.8 vs. 56.0 +/- 20.2 cm/s, P < 0.01, respectively). Overall, moderate, but significative, linear correlation was found between IM peak and mean diastolic velocity and LV-SWS (r = 0.41, P = 0.01, and r = 0.44, P = 0.007, respectively), whereas there was no correlation with wall thickening and LV mass. CONCLUSIONS: Main findings from the present study likely suggest that in patients with mild-to-moderate LVH, high blood flow velocity in the IM arterioles, but not in the LAD, may be related to an increase in LV-SWS, rather independent on the absolute LV mass.     

Myocardial perfusion by contrast echocardiography: diagnosis of coronary artery disease using contrast-enhanced stress echocardiography and assessment of coronary anatomy and flow reserve

The advent of intravenous contrast agents, and newer ultrasound technology to enhance their detection, promises to improve and augment our conventional stress echocardiographic practice by improving diagnostic accuracy and providing novel information regarding myocardial perfusion and functional assessment of the coronary vasculature. The combination of intravenous contrast and harmonic stress echocardiography is a powerful tool for improved wall motion analysis through enhanced image quality, routinely permitting the evaluation of patients with suboptimal images. In this era of cost containment, we await studies in large populations addressing resource utilization and cost-effectiveness to determine if, indeed, all patients presenting with stress echocardiography should receive contrast. Myocardial perfusion can be observed using the technique, but the complex interactions of microbubbles and ultrasound in patients must be understood more fully before its implementation becomes routine practice. Non-invasive imaging of coronary arteries using contrast-enhanced transthoracic harmonic echo/Doppler promises to expand the field of diagnostic and experimental echocardiography, bringing new insight into the pathophysiology of ischemic and non-ischemic heart disease. The continued development of newer contrast agents and refinement of ultrasound imaging equipment ensures that the applications of contrast echocardiography in the assessment of CAD will continue to increase.     

Blood flow patterns in the left ventricle in patients with myocardial infarction and ventricular aneurysm: evaluation using real-time two-dimensional Doppler echocardiography

To evaluate how the intraventricular blood flow is affected by the size of a left ventricular aneurysm and ventricular dysfunction, systolic left ventricular blood flow patterns were evaluated using two-dimensional Doppler flow images (real-time 2-D Doppler echo). The subjects consisted of 10 normal controls, 35 patients with anteroseptal infarction, two patients with inferior infarction and five patients with anteroseptal-inferior infarctions. The systolic period was divided into three subsets; early, mid- and end-systole. Forty-two patients with myocardial infarction were classified into three groups according to the left ventricular inflow patterns on real-time 2-D Doppler echo using the apical left ventricular long-axis approach; i.e., inflow signals confined to early systole (Group I), visualized up to mid-systole (Group II) and end-systole (Group III). Left ventricular end-diastolic dimension (LVDd), left ventricular end-systolic dimension (LVDs), and % non-contractile circumference (delta L) were calculated by the same echocardiographic approach. Ejection fraction (EF) was calculated by left ventricular cineangiography using the Simpson's method. The left ventricular inflow Doppler signals in the normal controls and Group I turned in the apex and then directed toward the left ventricular outflow tract during late diastole and early systole. Significant differences in EF were observed among the three groups. EF in Group I, II and III was 53 +/- 9%, 41 +/- 8% and 29 +/- 7%, respectively. However, LVDd, LVDs and delta L had the largest values in Group III and the smallest values in Group I. LVDd, LVDs and delta L were smallest in Group I and largest in Group III. In the normal controls, the left ventricular inflow signals proceeded to the apex and directed toward the left ventricular outflow tract in the early systolic period. Various changes in the inflow pattern were observed in patients with myocardial infarction and severe wall motion abnormalities, including delayed timing in proceeding from the apex to the left ventricular outflow tract, stagnant blood at the apex and further inflow of blood toward the apex even during end-systole. The patients with sustained inflow during late systole had hypofunction of the left ventricle as demonstrated by smaller EF and larger LVDd, LVDs, and delta L. In conclusion, the observation of intracardiac blood flows by real-time 2-D Doppler echo is of help in evaluating the severity of myocardial infarction.     

Digital subtraction contrast echocardiography: a new method for the evaluation of regional myocardial perfusion

The potential of contrast enhanced digital subtraction echocardiography to demonstrate and quantitate myocardial perfusion was evaluated in 36 patients undergoing routine coronary arteriography or angioplasty. In 24 technically successful studies, multiple cross sectional echocardiographic images, obtained before and after intracoronary (sonicated contrast) injection, were stored by high speed, real time data transfer to an on line minicomputer. Subsequent digital subtraction processing of the stored image data provided composite images in which the distribution of myocardial perfusion was easily seen. Quantitative analysis of peak enhanced myocardial grey level and washout half time successfully differentiated between myocardial segments in which angiography had suggested normal, reduced, and grossly impaired or absent perfusion. The results suggest that this new method of digital image capture and quantitative processing has substantial advantages over previous off line qualitative techniques. It is likely to be of considerable value for routine coronary arteriography, angioplasty, and coronary thrombolysis.     

超声四维应变技术结合实时心肌超声造影技术评价冠心病患者左室心肌灌注及运动功能改变的价值

目的 探索四维应变技术（4D-SI）结合实时心肌超声造影技术（MCE）评价冠心病患者心肌灌注及运动功能的临床价值。 方法 选取经冠状动脉造影确诊为冠心病的患者 30 例,血供异常的心肌节段按供血冠脉狭窄程度分为轻度、中度和重度狭窄组,并选取 15 例健康体检者作为正常对照组。所有分组均进行 MCE 和 4D-SI 检查,得出长轴应变 (4D-GLPS) 、环向应变 (4D-GCPS) 、面积应变 (4D-GAPS) 及径向应变 (4D-GRPS) 参数指标分析左室各节段心肌运动功能,并应用 MCE 再灌注充盈曲线获得 A 值和 β 值分析各节段心肌血流灌注情况。 结果 在异常冠脉供血区,中度和重度狭窄组的 β 值和各应变值均低于对照组 (P<0.05),轻度狭窄组的 4D-GLPS、4D-GAPS 值低于对照组 (P<0.05)。单参数 ROC 曲线分析结果显示,4D-GLPS 和 4D-GAPS 诊断早期心肌损伤价值较高;多参数联合的 ROC 曲线分析结果显示,和单一技术相比,各应变值联合 β 值诊断中、重度冠脉狭窄节段的 AUC 较大 ,灵敏度及特异度相对较高。 结论 MCE 的再灌注参数 β 值和 4D-SI 技术参数 4D-GLPS、4D-GCPS、4D-GAPS 和 4D-GRPS 均可发现静息状态下 >75% 的冠脉狭窄引起的心肌缺血,其中 4D-GLPS、4D-GAPS 能够发现轻度狭窄组早期的心肌损伤改变,且两种技术结合诊断中、重度冠脉狭窄的价值明显高于仅应用单一技术。     

Optimal time for predicting left ventricular remodeling after successful primary coronary angioplasty in acute myocardial infarction using serial myocardial contrast echocardiography and magnetic resonance imaging.

The objective of this study was to determine the optimal time to assess microvascular integrity within the risk area for myocardial infarction in order to predict unfavorable left ventricular remodeling (LVR) after successful primary coronary angioplasty. Fifty-three patients who underwent myocardial contrast echocardiography (MCE) just before recanalization, shortly after and 1 day (Day 2) and 3 weeks after recanalization were studied. The no- and low-reflow ratio (LR ratio) was analyzed at each stage. The wall-thinning ratio within the risk area was determined using magnetic resonance imaging performed 3-4 weeks after the recanalization. Thirteen of the 53 patients showed LVR 3-8 months after recanalization. The optimal time to predict LVR was found to be Day 2 based on the receiver operating characteristic curves. The LR ratio on Day 2 (chi2=7.39, p=0.007) and the collateral circulation before recanalization (chi2=4.57, p=0.03) were chosen as independent variables for predicting LVR. Patients with greater than 0.43 in the LR ratio on Day 2 showed a lower wall-thinning ratio (58+/-19% vs 72+/-20%, p=0.05). This study shows that the optimal time to estimate the microvascular integrity for predicting LVR is 1 day after recanalization, which is neither shortly after recanalization nor during the convalescent stage.     

Intraventricular isovolumic relaxation flow patterns improve the predicting power of Doppler echocardiography for the left ventricular filling pressure in patients with anterior wall myocardial infarction

BACKGROUND AND PURPOSE: Previous studies have shown that left ventricular systolic asynchrony affects both the relaxation and filling phases of diastole. The purpose of this study was to delinate how the anterior wall dyssynergy influenced the intraventricular flow redistribution patterns during the isovolumic relaxation (IVR) period, which delineated the changes in diastolic suction performance and, therefore, determined the significant Doppler flow variables for predicting left ventricular filling pressure. METHODS: Seventy-three patients with anterior wall myocardial infarction and dyssynergy were enrolled. Those who exhibited the whole IVR intraventricular flow redistributing toward the mitral apparatus, which indicated the reverse physiologic intraventricular pressure gradient in early diastole, were classified as group B, otherwise, as group A. The Doppler echocardiographic variables of mitral inflow were correlated with the left ventricular end-diastolic pressures (LVEDP). RESULTS: With lower ejection fraction rate and more apical dyssynergy, the group B patients had much slower mitral flow propagation. For group A patients, the independent determinants for LVEDP were the ratio of mitral flow propagation rate to peak velocity in early diastole, the early mitral flow deceleration time and the IVR time, all occurring in early diastole. In contrast, the only independent determinant for LVEDP in group B patients was the ratio of mitral peak flow velocity in early diastole to that in late diastole. CONCLUSIONS: The intraventricular IVR flow patterns could delineate how the left ventricular systolic dyssynergy influenced the diastolic process, and determine which echocardiographic variables were more useful for predicting LVEDP in patients with anterior wall myocardial infarction.