Regional Diastolic Function Research Articles

Tissue-Engineered Myocardial Patch Derived From Extracellular Matrix Provides Regional Mechanical Function

Extracellular matrix (ECM), a tissue-engineered scaffold, recently demonstrated cardiomyocyte population after myocardial implantation. Surgical restoration of myocardium frequently uses Dacron as a myocardial patch. We hypothesized that an ECM-derived myocardial patch would provide a mechanical benefit not seen with Dacron. Using a canine model, a full thickness defect in the right ventricle was repaired with either Dacron or ECM. A third group had no surgery and determined baseline RV function. Eight weeks later, global systolic function was assessed by the preload recruitable stroke work relationship. Regional systolic function was measured by systolic area contraction (SAC), calculated by high density mechanical mapping. Tau was used to assess global diastolic function. Recoil rate and diastolic shear were used as measures of regional diastolic function. After functional data acquisition, tissue was fixed for histological evaluation. Global systolic and diastolic functions were similar at baseline and after ECM and Dacron implantation. Regional systolic function was greater in the ECM group compared with the Dacron group (SAC: 4.1+/-0.9% versus -1.8+/-1.1, P<0.05). Regional diastolic function was also greater in the ECM group (recoil rate (degrees sec(-1)): -44+/-7 versus -17+/-2, ECM versus Dacron; P<0.05). Immunohistochemical analysis revealed cardiomyocytes in the ECM implant region, a finding not seen with Dacron. At 8 weeks, an ECM-derived tissue-engineered myocardial patch provides regional mechanical function, likely related to cardiomyocyte population. These results are in sharp contrast to Dacron, a commonly used myocardial patch.

Volumetric Quantification of Global and Regional Left Ventricular Function From Real-Time Three-Dimensional Echocardiographic Images

Real-time 3D echocardiographic (RT3DE) data sets contain dynamic volumetric information on cardiac function. However, quantification of left ventricular (LV) function from 3D echocardiographic data is performed on cut-planes extracted from the 3D data sets and thus does not fully exploit the volumetric information. Accordingly, we developed a volumetric analysis technique aimed at quantification of global and regional LV function. RT3DE images obtained in 30 patients (Philips 7500) were analyzed by use of custom software based on the level-set approach for semiautomated detection of LV endocardial surface throughout the cardiac cycle, from which global and regional LV volume (LVV)-time and wall motion (WM)-time curves were obtained. The study design included 3 protocols. In protocol 1, time curves obtained in 16 patients were compared point-by-point with MRI data (linear regression and Bland-Altman analyses). Global LVV correlated highly with MRI (r=0.98; y=0.99x+2.3) with minimal bias (1.4 mL) and narrow limits of agreement (+/-20 mL). WM correlated highly only in basal and midventricular segments (r=0.88; y=0.85x+0.7). In protocol 2, we tested the ability of this technique to differentiate populations with known differences in LV function by studying 9 patients with dilated cardiomyopathy and 9 normal subjects. All calculated indices of global and regional systolic and diastolic LV function were significantly different between the groups. In protocol 3, we tested the feasibility of automated detection of regional WM abnormalities in 11 patients. In each segment, abnormality was detected when regional shortening fraction was below a threshold obtained in normal subjects. The automated detection agreed with expert interpretation of 2D WM in 86% of segments. Volumetric analysis of RT3DE data is clinically feasible and allows fast, semiautomated, dynamic measurement of LVV and automated detection of regional WM abnormalities.

Global and Regional Left Ventricular Function in Patients Undergoing Transcatheter Closure of Secundum Atrial Septal Defect

This study sought to evaluate global and regional left ventricular (LV) function before and early after device closure of atrial septal defects (ASDs) in patients with normal pulmonary pressure. Global LV diastolic function was unaffected by ASD closure. An improvement in global LV systolic function at rest resulted in an increase in stroke volume at rest. Nevertheless, total cardiac output did not change after the procedure, because of a decrease in heart rate at rest counterbalancing the increase in stroke volume. Thus, lateral and inferior LV regional systolic function were preserved after device implantation. Moreover, no changes in regional LV diastolic function were highlighted during the study.

251 Age related changes in global and regional left ventricular diastolic function: a pulsed Doppler tissue imaging study

251 Age related changes in global and regional left ventricular diastolic function: a pulsed Doppler tissue imaging study

Losartan improves regional left ventricular systolic and diastolic function in patients with hypertension: accurate evaluation using a newly developed color-coded tissue doppler imaging technique

BackgroundAngiotensin II receptor antagonists have recently been accepted as antihypertensive therapy. Tissue Doppler imaging (TDI) has been developed as a noninvasive tool to assess quantitatively regional myocardial motion abnormalities. This study was designed to determine whether our newly developed technique of color-coded TDI may be a useful means of quantifying the improvement in regional left ventricular (LV) myocardial contractility and relaxation after treatment with losartan in patients with hypertension. Methods and resultsLosartan (50 to 100 mg) was administered for 6 months to 37 previously untreated patients with essential hypertension. Averaged myocardial velocity profiles (MVPs) for color-coded TDI were recorded in the ventricular septum and LV posterior wall before and after treatment. Peak myocardial velocities and peak myocardial velocity gradients (MVGs) in the LV walls were determined during systole and early diastole. The plasma concentration of transforming growth factor (TGF)-β1 also was measured in all patients. Blood pressure and plasma TGF-β1 level decreased after initiation of losartan therapy. The LV mass index and LV meridional end-systolic wall stress also decreased after treatment with losartan. LV geometry changed from a pattern consistent with concentric hypertrophy to normal geometry in 10 patients and to a pattern consistent with concentric remodeling in 5 patients, and from concentric remodeling to normal geometry in 5 patients after treatment with losartan. The ratio of early to late diastolic filling for the transmitral flow velocity increased after losartan treatment. The peak systolic and early diastolic myocardial velocities and MVGs in the ventricular septum and LV posterior wall increased after treatment with losartan, although the values 6 months after treatment with losartan were still lower than those in normal individuals. There were good correlations between changes in plasma TGF-β1 level and changes in systolic and early diastolic MVGs 6 months after losartan. However, there were no significant correlations between changes in the systolic blood pressure and LV end-systolic wall stress and changes in the TDI parameters. ConclusionLosartan improves regional LV function in patients with hypertension. Our newly developed averaged MVP and MVG measurements may be useful for accurately evaluating regional LV myocardial contractility and relaxation in these patients.

Persistent diastolic dysfunction despite complete systolic functional recovery after reperfused acute myocardial infarction demonstrated by tagged magnetic resonance imaging.

This study was designed to characterise both the systolic and diastolic mechanical properties of regions with different degrees of myocardial ischaemic injury after reperfused acute myocardial infarction (AMI). Fourteen dogs underwent 90-min coronary artery occlusion followed by reperfusion. Image acquisition was performed 24 h after reperfusion using three techniques: tagged, first-pass perfusion and delayed-enhancement magnetic resonance imaging (MRI). Systolic circumferential strain and both systolic and diastolic strain rates were calculated in 30 segments/animal. Transmural AMI segments displayed reduced systolic contractility when compared to subendocardial AMI segments (systolic strain = -2.5 +/- 0.5% versus -6.0 +/- 0.9%, P < 0.01 and systolic strain rate = -0.11 +/- 0.12 versus -0.82 +/- 0.16 s(-1), P < 0.01), and both exhibited significant systolic and diastolic dysfunction compared to remote. Moreover, AMI segments presenting with microvascular obstruction ("no-reflow") displayed further compromise of systolic and diastolic regional function (P < 0.05 for both). Importantly, risk region segments only exhibited diastolic impairment (diastolic strain rate = 1.62 +/- 0.14 versus 2.99 +/- 0.13 s(-1), P < 0.001), but not systolic dysfunction compared to remote 24 h after reperfusion. Reversibly injured regions can demonstrate persistent diastolic dysfunction despite complete systolic functional recovery after reperfused AMI. Moreover, the presence of no-reflow entails profound systolic and diastolic dysfunction. Finally, tagged magnetic resonance imaging (MRI) strain rate analysis provides detailed mechanical characterisation of regions with different degrees of myocardial ischaemic injury.

Differences in regional systolic and diastolic function by Doppler tissue imaging in patients with hypertrophic cardiomyopathy and hypertrophy caused by hypertension

Objective Doppler tissue (DT) velocity abnormalities have been described in patients with pathologic left ventricular hypertrophy (LVH). Impaired myocardial function has been suggested as a primary disorder in hypertrophic cardiomyopathy (HCM) and differences in DT parameters have been reported to be distinguishable from other LVH causes. We evaluated DT differences for patients with LVH caused by hypertension and patients with HCM, assessing regional systolic and diastolic function. Methods A total of 62 participants were studied: 21 with HCM; 22 with LVH secondary to hypertension; and 19 control subjects. DT was used to record mitral annulobasal segment motion in the longitudinal axis. Systolic and diastolic velocities were measured at lateral and septal sites, and well-known ratios were obtained for diastolic assessment. A new global function index (GFI) that evaluates both systole and diastole was also calculated (GFI = [Emi/E DT]/S DT [s × cm −1], where mi is mitral inflow, E is E wave, and S is systolic wave). Results Comparison showed significant differences in all parameters evaluated at the septal-basal segment and a GFI value of 1.77 showed 85% sensitivity and 75% specificity for detecting HCM when interventricular septum thickness was increased. Conclusions In the presence of unexplained LVH, markedly decreased DT velocities at basal septum efficiently detect myocardial dysfunction at this segment, and a calculated GFI > 1.77 strongly supports the diagnosis of HCM.

Left ventricular regional systolic and diastolic function of inappropriate left ventricular hypertrophy in patients with systemic hypertension

P-355 Key Words: Inappropriate, Hypertrophy, Regional function

Effects of losartan and captopril on left ventricular systolic and diastolic function after acute myocardial infarction: Results of the Optimal Trial in Myocardial Infarction with Angiotensin II antagonist losartan (optimaal) echocardiographic substudy

Background Angiotensin-converting enzyme inhibitors have been shown to attenuate adverse remodeling after acute myocardial infarction (AMI), and the same has been suggested for angiotensin II type 1 receptor antagonists in animal models. Therefore the aim of the study was to compare the effects of losartan and captopril on regional systolic, diastolic, and overall left ventricular (LV) function after AMI. Methods Two hundred twenty-five patients aged ≥50 years with documented AMI and heart failure and/or LV dysfunction were randomly assigned treatment with either losartan (50 mg/d) or captopril (50 mg 3 times/d). Echocardiography was performed at randomization and after 3 months; echocardiograms were analyzed blinded at the core laboratory. Main outcome measures were changes in wall motion score index (WMSI), E-wave deceleration time (E-DT), and Tei index of overall LV function. Results WMSI decreased in both groups (losartan 1.58 ± 0.23 to 1.52 ± 0.26, P = .009, captopril 1.60 ± 0.24 to 1.48 ± 0.22, P < .001), although the decrease was greater in patients allocated to captopril (captopril −0.12 ± 0.17 vs losartan −0.05 ± 0.19, P = .007). In both groups E-DT increased, although the increase was significant only in patients treated with captoril (193 ± 61 ms to 208 ± 70 ms, P = .05). The change in E-DT was not different between treatment groups (captopril 14 ± 74 ms vs losartan 7 ± 80 ms, P = .52). Tei index decreased in both groups (losartan 0.59 ± 0.13 to 0.55 ± 0.15, P = .04, captopril 0.62 ± 0.15 to 0.55 ± 0.13, P < .001). However, the reduction was significantly greater in patients treated with captopril (captopril −0.08 ± 0.14 vs losartan −0.03 ± 0.14, P = .01). Conclusion Losartan and captopril improve systolic and overall LV function after AMI, but the benefit is greater for patients treated with captopril.

TISSUE CHARACTERIZATION TO DIFFERENTIATE PATHOLOGICAL FROM PHYSIOLOGICAL HYPERTROPHY IN PATIENTS WITH HYPERTENSION AND ATHLETES

Precedents: In pathological left ventricular (LV) hypertrophy (H) of hypertensive patients (P) there is a deposition of collagen. Myocardial fibrosis is one of the factors responsible for systolic and diastolic dysfunction. Athletes increase their ventricular mass as physiological ventricular H. Integrated backscatter (IB) demonstrates changes in myocardial acoustic properties, depending upon their composition and function. Objectives: (1).Assess the capability of IB to differentiate physiological from pathological H. (2).Correlate IB with overall and regional systolic and diastolic functions. Methods: Group I(GI):13 hypertensive P with an LV mass index (LVMI)&gt;124 gr/m2, Group II(G2):11 athletes, Group III(G3): 8 volunteers. We determined overall systolic and diastolic functions and regional function of the basal septum, IB and cyclic variation of the IB (CVIB) of the posterior wall. Results: Age (years): G1:52 ± 15, G2:28 ± 8 G3:35 ± 8 p = 0.000; Sex: G1:m/f 12/1, G2: m/f 9/2, G3: m/f 4/4, LVMI: G1: 180.1 ± 58 gr/m2, G2:130.2 ± 20 gr/m2 G3: 90.2 ± 16 gr/m2 p = 0.000. Left atrial area (LAA): G1: 22 ± 4 cm2, G2: 18.8 ± 1.8 cm2, G3: 15.8 cm2 p = 0.001, mid‐wall shortening fraction (MWSF): G1:26.9 ± 3.5, G2:27.5 ± 4 G3:25 ± 3 p = NS; CVIB: G1:5,3 ± 2,5 G2:7.6 ± 2,1 G3:6.4 ± 1.1 P = 0.048.Correlation of IB and MWSF, p = NS; IB and MWSF p = NS, IB and CVIB:‐0.56 p = 0.005. Group 1 Goup 2 Group 3 P Correlation IB P Regional S 4.83 ± 0.9 5.68 ± 0.8 5.65 ± 1.3 0.03 regional −0.49 (p = cm/seg S 0.015) Regional e/a 0.8 ± 0.3 2.1 ± 0.6 1.9 ± 1.3 0.002 e/a −0.43 (p = 0.038) Transmitral 1.2 ± 0.3 2 ± 0.75 1.9 ± 0.9 0.008 E/A NS E/A BI (dB) 41 ± 6 29 ± 6 35 ± 8 0.001 LAA 0.43 (p = 0.037) Conclusion: (1). An increase in IB was seen in hypertensive patients, which may be the echocardiographic manifestation of myocardial fibrosis and/or depressed ventricular function. (2). IB differentiates physiological from pathological H. (3). Regional systolic and diastolic functions correlate inversely with IB in hypertensive patients, whereas LAA correlates with IB.

QUANTIFICATION OF REGIONAL MYOCARDIAL FUNCTION: IMPROVED DETECTION OF MYOCARDIAL ISCHEMIA IN DIABETIC PATIENTS DURING DOBUTAMINE DOPPLER MYOCARDIAL IMAGING ECHOCARDIOGRAPHY

The aim of the study was to evaluate the value of pulsed wave Doppler myocardial imaging (PW DMI) in detecting myocardial ischemia (mi) during dobutamine stress echocardiography (DSE) in diabetic patients. Methods: We studied 40 diabetic patients with known or suspected coronary artery disease. In all patients DSE (from 5 up to 40 mcg/kg/min infused in 3‐minute stages, plus atropine 1 mg if needed) was performed. DSE identified ischemia by the occurrence of wall motion abnormalities (WMA) with stress (positive DSE). Apical views were used to assess myocardial velocities (mv; Acuson‐ Sequoia, PW DMI) on baseline and at peak stres. The left ventricle was divided into 11 segments. The sample volume was placed in each adequately visualized segment and in each segment we measured peak mv of systolic (S), early (E), and late (A) diastolic waves and calculated their ratio (E/A) as an index of regional diastolic function. Results: Myocardial velocities were measured in 374 (85%) of 440 possible myocardial segments. During DSE in 21 (52.5%) patients WMA were detected in 73 (37%) of 197 adequately visualized segments, while in 19 (47.5%) patients WMA did not appear. Of 21 patients with DSE‐provoked WMA, in 9 (42.9%) patients symptomatic and in 12 (57.1%) patients silent mi appeared. In segments with DSE‐provoked symptomatic and silent WMA the ratio of E/A decreased by 23.7% and 20.1% (p &lt; 0.001 for both) and S decreased by 18.7% (p &lt; 0.005) and 14.4% (p &lt; 0.02) compared to baseline values. Of 301 segments without DSE‐induced WMA in 13 (4.3%) segments (6 in patients with positive and 7 segments in patients with negative DSE) we also found inversion of the E/A ratio (from 1.04 ± 0.08 to 0.94 ± 0.09, p &lt; 0.005). In 288 other segments without WMA ratio E/A and S mv significantly increased (p &lt; 0.001 for both). Conclusion: Quantification of regional myocardial function during conventional DSE in diabetic patients showed that symptomatic as well as silent mi is associated with significant decrease of E/A ratio and S mv but changes are more pronounced in symptomatic mi. Inverted regional E/A ratio may uncover super‐silent mi, which is not sufficient to provoke WMA.

510 Role of Doppler tissue imaging in the assessment of diastolic dysfunction in hypertensive patients with and without concentric geometric remodeling

It has been shown that in patients with essential hypertension and cardiac hypertrophy Tissue Doppler Imaging (TDI) is able to detect impairment of diastolic function more accurately than pulsed transmitralic Doppler (TD). The aim of this study was to assess if, in hypertensive patients without cardiac hypertrophy, there are differences in diastolic function evaluated by using TDI or TD. We studied 17 patients (46±9 years, 11 male) with never treated essential hypertension. Echocardiographic evaluation was used to assess the following parameters: concentric remodelling (CR) pattern, defined as a normal left ventricular mass index with a relative wall thickness >0.45; global diastolic dysfunction (GDD), detected by correcting for age the TD flow early to atrial (E/A) ratio values; regional diastolic dysfunction (RDD) evaluated by TDI, with the sample volume positioned within the basal septum and defined according to the age-corrected tissue E/A ratio values. CR was found in 12 patients (70%); among these, 4 showed both GDD and RDD, while 5 patients showed only RDD. In the absence of CR, no patient showed either GDD or RDD. At Fisher test analysis, RDD was significantly associated with the presence of CR (p=0.019), whereas no significant association was found between CR and GDD. TDI showed a higher sensitivity in detecting diastolic dysfunction than TD (75% vs 33%) and a higher negative predictive value (63% vs 38%); both TDI and TD had a specificity and positive predictive value of 100%. In conclusion, in hypertensive patients with cardiac remodeling an abnormal regional diastolic function can be observed more frequently than a global diastolic dysfunction, thus suggesting that TDI is able to detect early impairment of diastolic function more accurately than pulsed transmitralic Doppler even in the absence of cardiac hypertrophy.

Use of myocardial tissue Doppler imaging for intraoperative monitoring of left ventricular function

Detection of myocardial ischaemia during surgery is usually by assessment of regional wall motion using two-dimensional transoesophageal echocardiography (TOE). Tissue Doppler imaging (TDI) may assist this assessment and improve its accuracy. We measured peak myocardial velocities in the anterior mid-wall of the left ventricle by TOE and pulsed-wave TDI in addition to transmitral flow velocity, two-dimensional echocardiography and cardiovascular variables. We studied 42 patients before and after coronary bypass surgery with left internal mammary artery grafts. Peak systolic and early and late diastolic velocity measurements of the anterior mid-wall were obtained in all patients. Variation between and within observers was small (<6%). Peak systolic thickening velocity correlated with visual assessment of anterior wall motion score, fractional area change of the left ventricle and left ventricular systolic wall stress. Because of the wide overlap of systolic velocity between the segments with normal and abnormal wall motion, it was not possible to separate normal from abnormal segments on the basis of TDI-derived velocity alone. The diastolic velocity in the anterior wall reflected the transmitral filling pattern. After surgery, the peak systolic and late diastolic anterior wall velocities increased (from 4.2 (95% confidence interval 4.0, 4.7) to 5.7 (4.8, 6.3) cm s(-1) and from 3.5 (3.2, 3.9) to 6.0 (5.1, 6.9) cm s(-1) respectively), while the ratio of early to late diastolic velocity decreased from 1.5 (1.2, 1.7) to 1.0 (0.8, 1.2). TDI changes characteristic of new myocardial ischaemia were not seen in any patient. Intraoperative measurement of TDI in the anterior wall of the left ventricle is feasible and provides additional quantitative information on both regional and global systolic and diastolic function. We found changes in myocardial velocities indicating improvement in the systolic and impairment in the diastolic function of the anterior wall of the left ventricle immediately after mammary artery grafting.

Transesophageal echocardiography with tissue doppler imaging in the assessment of global and regional systolic and diastolic right ventricular function in atrial septal defects

Transesophageal echocardiography with tissue doppler imaging in the assessment of global and regional systolic and diastolic right ventricular function in atrial septal defects

Prolonged postischemic regional left ventricular delayed relaxation or diastolic asynchrony detected by color kinesis following coronary vasospasm

Coronary vasospasm is characterized by transient myocardial ischemia resulting from temporary coronary flow obstruction followed by reperfusion.1,2 Several studies have suggested that left ventricular (LV) diastolic function may be a more sensitive marker of coronary ischemia than systolic function.3–6 It is conceivable that impaired or stunned regional diastolic function follows transient severe myocardial ischemia associated with coronary vasospasm. To date, the postischemic process of normalization of regional diastolic function in patients with coronary vasospasm has not been investigated. We hypothesized that the adverse effect of spasm-induced ischemia on regional diastolic function would persist well beyond the ischemic event. Color kinesis (CK) (Philips Medical Systems, Andover, Massachusetts), a new technique based on acoustic quantification, has recently been developed to facilitate the evaluation of regional wall motion.7,8 The present study was designed to investigate whether impaired regional LV wall motion or diastolic asynchrony could actually be diagnosed using this method, and, if so, how long the regional diastolic dysfunction persists after coronary vasospasm.

Colour encoded endocardial tracking: the current state of play.

Colour encoded endocardial tracking is a new echocardiographic technique designed to track ventricular wall endocardial motion and thus help in assessing both regional and global ventricular function. It is an extension of automatic boundary detection, a technique based on integrated backscatter analysis. By utilizing automated boundary detection, colour encoded endocardial tracking automatically tracks endocardial motion on a frame by frame basis. Colour overlays are then superimposed on the grey-scale images. These colour overlays are updated in real time, providing an integrated display of the magnitude and timing of endocardial wall motion. With further post-processing analysis, this technique can provide quantitative information on both global and regional ventricular systolic and diastolic function.

Myocardial ischemia assessed by Tc99m MIBI SPECT and left ventricle regional systolic and diastolic function evaluated by tissue Doppler echocardiography.

Tc99m MIBI single-photon emission computed tomography (SPECT) study facilitates the evaluation of the regional myocardial perfusion and tissue Doppler echocardiography imaging facilitates the quantitative assessment of the regional systolic and diastolic function of the myocardium. The aim of the study was an assessment of the correlation between regional rest myocardial perfusion defects and regional rest systolic and diastolic myocardial velocities in patients with ischemic heart disease (IHD). In 40 IHD patients (33 men, 7 women) aged 43-74 years (mean 56 years) rest SPECT imaging with Tc99m MIBI and rest tissue Doppler examinations were performed. The control group consisted of 35 healthy sex and age matched pesons. The left ventricle was divided into 13 segments. The number of non-perfused segments in three myocardial perfusion regions (left anterior descending artery, circumflex artery, right coronary artery) was assessed in IHD patients. During tissue Doppler examination the maximal systolic and maximal early diastolic velocity of the myocardium in each segment were established in both examined groups. The systolic and diastolic myocardial velocities were significantly lower in IHD group as compared to control group. In the IHD group statistically significant decrease of systolic and diastolic velocities in relation to the number of non-perfused segments was found. In comparing the linear regression slopes for systolic and for diastolic myocardial velocities in terms of intensification of perfusion defects, a more pronounced decrease in diastolic velocity was encountered. Both systolic and diastolic myocardial velocities are decreased in the myocardial regions with perfusion defects, but the reduction of the diastolic velocity is higher than the reduction of the systolic velocities. Thus our results indicate a good correlation between the intensity of perfusion abnormalities and myocardial velocities. The levels of diastolic dysfunction is more pronounced than the level of systolic dysfunction in the ischemic myocardium.

Novel approach to the quantitation of regional left ventricular systolic and diastolic function using tissue Doppler imaging to create a myocardial velocity profile and gradient.

The myocardial velocity profile (MVP) and gradient (MVG) between the endocardium and epicardium of the left ventricular (LV) wall measured by color-coded tissue Doppler imaging (TDI) are new indices for evaluating regional LV myocardial function. However, accurate recording and measurement of the MVP is difficult using conventional methodology because of the stochastic nature of the ultrasound signal; that is, the effect of speckled noise. The aim of this study was to validate the accuracy and establish the validity of a newly developed method for measuring the MVP and MVG using 10 clinically normal controls and 10 patients with a hypertensive hypertrophied LV posterior wall. A non-isotropic, averaging algorithm was developed that was capable of obtaining a stable MVP (averaged MVP). Averaged MVP was recorded using parasternal, LV short-axis, color-coded TDI, placing regions of interest along the LV posterior wall with the reference point for angle-correction being at the center of LV contraction. The velocity from epicardium to endocardium within the region of interest was automatically angle-corrected to calculate the velocity component radially relative to the LV cavity and was spatially averaged along the circumference within the region of interest. Inter- and intraobserber variabilities of measurements were lower in the averaged MVP and MVG than in the conventional MVP and MVG. The correlation coefficients of the linear regression lines of systolic and early diastolic MVPs in the LV posterior wall were higher in all controls and hypertensive patients with the averaged method than with the conventional TDI procedures. The mean peak systolic and early diastolic MVGs were lower in the hypertensive group than in the controls. In conclusion, the newly developed averaged MVP provides a stable and reproducible index for the quantitative assessment of regional LV myocardial function.

Determinants of tissue Doppler measures of regional diastolic function during dobutamine stress echocardiography

Background Diastolic dysfunction induced by ischemia may alter transmitral blood flow, but this reflects global ventricular function, and pseudonormalization may occur with increased preload. Tissue Doppler may assess regional diastolic function and is relatively load-independent, but limited data exist regarding its application to stress testing. We sought to examine the stress response of regional diastolic parameters to dobutamine echocardiography (DbE). Methods Sixty-three patients underwent study with DbE: 20 with low probability of coronary artery disease (CAD) and 43 with CAD who underwent angiography. A standard DbE protocol was used, and segments were categorized as ischemic, scar, or normal. Color tissue Doppler was acquired at baseline and peak stress, and waveforms in the basal and mid segments were used to measure early filling (Em), late filling (Am), and E deceleration time. Significant CAD was defined by stenoses >50% vessel diameter. Results Diastolic parameters had limited feasibility because of merging of Em and Am waves at high heart rates and limited reproducibility. Nonetheless, compared with normal segments, segments subtended with significant stenoses showed a lower Em velocity at rest (6.2 ± 2.6 cm/s vs 4.8 ± 2.2 cm/s, P <.0001) and peak (7.5 ± 4.2 cm/s vs 5.1 ± 3.6 cm/s, P <.0001). Abnormal segments also showed a shorter E deceleration time (51 ± 27 ms vs 41 ± 27 ms, P =.0001) at base and peak. No changes were documented in Am. The same pattern was seen with segments identified as ischemic with wall motion score. However, in the absence of ischemia, segments of patients with left ventricular hypertrophy showed a lower Em velocity, with blunted Em responses to stress. Conclusion Regional diastolic function is sensitive to ischemia. However, a number of practical limitations limit the applicability of diastolic parameters for the quantification of stress echocardiography. (Am Heart J 2002;144:516-23.)

Assessment of diastolic function by cardiovascular magnetic resonance

Background The assessment of diastolic heart function has been hampered by multiple difficulties. Cardiovascular magnetic resonance (CMR) is a new, noninvasive technique to study cardiac function. Methods The literature on CMR for the analysis of diastolic function and its clinical applications is extensively reviewed. Results Analysis of ventricular filling velocity and volume flow, volumetric assessment of ventricular chamber volume, analysis of 3-dimensional myocardial strains, and assessment of myocardial energy content are numerous validated applications of CMR. With the advent of real-time imaging and automated analysis of myocardial strains, CMR tagging is a promising method to assess regional diastolic function. Today, many CMR techniques are leaving the experimental or developmental stage rapidly and becoming clinically available for the evaluation of diastolic function in heart disease. Conclusions CMR is emerging as a highly accurate and reproducible noninvasive 3-dimensional technique for the assessment of diastolic function. (Am Heart J 2002;144:198-205.)