Improved left ventricular diastolic filling in patients with coronary artery disease after percutaneous transluminal coronary angioplasty

Multicenter validation of a machine learning phase space electro-mechanical pulse wave analysis to predict elevated left ventricular end diastolic pressure at the point-of-care

BACKGROUND

Phase space is a mechanical systems approach and large-scale data representation of an object in 3-dimensional space. Whether such techniques can be applied to predict left ventricular pressures non-invasively and at the point-of-care is unknown.

OBJECTIVE

This study prospectively validated a phase space machine-learned approach based on a novel electro-mechanical pulse wave method of data collection through orthogonal voltage gradient (OVG) and photoplethysmography (PPG) for the prediction of elevated left ventricular end diastolic pressure (LVEDP).

METHODS

Consecutive outpatients across 15 US-based healthcare centers with symptoms suggestive of coronary artery disease were enrolled at the time of elective cardiac catheterization and underwent OVG and PPG data acquisition immediately prior to angiography with signals paired with LVEDP (IDENTIFY; NCT #03864081). The primary objective was to validate a ML algorithm for prediction of elevated LVEDP using a definition of ≥25 mmHg (study cohort) and normal LVEDP ≤ 12 mmHg (control cohort), using AUC as the measure of diagnostic accuracy. Secondary objectives included performance of the ML predictor in a propensity matched cohort (age and gender) and performance for an elevated LVEDP across a spectrum of comparative LVEDP (<12 through 24 at 1 mmHg increments). Features were extracted from the OVG and PPG datasets and were analyzed using machine-learning approaches.

RESULTS

The study cohort consisted of 684 subjects stratified into three LVEDP categories, ≤12 mmHg (N = 258), LVEDP 13-24 mmHg (N = 347), and LVEDP ≥25 mmHg (N = 79). Testing of the ML predictor demonstrated an AUC of 0.81 (95% CI 0.76-0.86) for the prediction of an elevated LVEDP with a sensitivity of 82% and specificity of 68%, respectively. Among a propensity matched cohort (N = 79) the ML predictor demonstrated a similar result AUC 0.79 (95% CI: 0.72-0.8). Using a constant definition of elevated LVEDP and varying the lower threshold across LVEDP the ML predictor demonstrated and AUC ranging from 0.79-0.82.

CONCLUSION

The phase space ML analysis provides a robust prediction for an elevated LVEDP at the point-of-care. These data suggest a potential role for an OVG and PPG derived electro-mechanical pulse wave strategy to determine if LVEDP is elevated in patients with symptoms suggestive of cardiac disease.

Different Pathophysiology and Outcomes of Heart Failure With Preserved Ejection Fraction Stratified by K-Means Clustering

Background: Stratified medicine may enable the development of effective treatments for particular groups of patients with heart failure with preserved ejection fraction (HFpEF); however, the heterogeneity of this syndrome makes it difficult to group patients together by common disease features. The aim of the present study was to find new subgroups of HFpEF using machine learning. Methods: K-means clustering was used to stratify patients with HFpEF. We retrospectively enrolled 350 outpatients with HFpEF. Their clinical characteristics, blood sample test results and hemodynamic parameters assessed by echocardiography, electrocardiography and jugular venous pulse, and clinical outcomes were applied to k-means clustering. The optimal k was detected using Hartigan's rule. Results: HFpEF was stratified into four groups. The characteristic feature in group 1 was left ventricular relaxation abnormality. Compared with group 1, patients in groups 2, 3, and 4 had a high mean mitral E/e' ratio. The estimated glomerular filtration rate was lower in group 2 than in group 3 (median 51 ml/min/1.73 m² vs. 63 ml/min/1.73 m² p < 0.05). The prevalence of less-distensible right ventricle and atrial fibrillation was higher, and the deceleration time of mitral inflow was shorter in group 3 than in group 2 (93 vs. 22% p < 0.05, 95 vs. 1% p < 0.05, and median 167 vs. 223 ms p < 0.05, respectively). Group 4 was characterized by older age (median 85 years) and had a high systolic pulmonary arterial pressure (median 37 mmHg), less-distensible right ventricle (89%) and renal dysfunction (median 54 ml/min/1.73 m²). Compared with group 1, group 4 exhibited the highest risk of the cardiac events (hazard ratio [HR]: 19; 95% confidence interval [CI] 8.9-41); group 2 and 3 demonstrated similar rates of cardiac events (group 2 HR: 5.1; 95% CI 2.2-12; group 3 HR: 3.7; 95%CI, 1.3-10). The event-free rates were the lowest in group 4 (p for trend < 0.001). Conclusions: K-means clustering divided HFpEF into 4 groups. Older patients with HFpEF may suffer from complication of RV afterload mismatch and renal dysfunction. Our study may be useful for stratified medicine for HFpEF.

The relationship between coronary slow flow phenomenon and carotid femoral pulse wave velocity and aortic elastic properties

Introduction

In this study, we aimed to investigate the relationship between coronary slow flow (CSF) and carotid-femoral pulse wave velocity (CFPWV).

Methods

78 (27 women, mean age 43.95 ± 7.28) patients with CSF, and 70 (22 women, mean age 44.34 ± 7.08) healthy individuals were included in the study. Arterial stiffness measurement was performed to both groups via CFPWV, which is considered the gold standard. Aortic elastic properties (ASI-β and aortic distensibility) were evaluated in both groups.

Results

The CSF group had significantly higher CFPWV and aortic distensibility values and significantly lower ASI-β values compared to the control group. There was a positive correlation between TIMI frame count (TFC) obtained in all coronary arteries and CFPWV and aortic distensibility, and a negative correlation between TFC and ASI-β. It was determined that CFPWV predicted CSF with 97% specificity and 98% sensitivity at a 7.68 cut-off value (ROC area = 994, p < 0.001). ASI-β was determined to predict CSF with 64% specificity and 47% sensitivity at a 2.98 cut-off value (ROC area = 047, p < 0.001). Aortic distensibility was determined to predict CSF with 76% specificity and 79% sensitivity at a 3.94 cut-off value (ROC area = 706, p < 0.001).

Conclusion

Arterial stiffness increases in CSF patients, suggesting that CSF is a systemic pathology rather than a local disease and that a systemic cause such as atherosclerosis plays a role in etiology.

Left Atrial Strain in Evaluation of Heart Failure with Preserved Ejection Fraction

BACKGROUND

Patients with heart failure with preserved ejection fraction (HFpEF) may have elevated left ventricular filling pressure with exercise (LVFP-ex), despite normal LVFP at rest. The aim of this study was to assess the diagnostic value of resting left atrial strain (LAS) in detecting elevated LVFP-ex in patients with dyspnea evaluated on exercise stress echocardiography.

METHODS

Two-dimensional speckle-tracking analysis for LAS was performed in 669 consecutive patients (mean age, 64 ± 14 years; 53% men) who underwent treadmill echocardiographic evaluation and had left ventricular ejection fractions ≥ 50%. Assessment of LVFP at rest LVFP-ex was based on the 2016 American Society of Echocardiography guidelines for diastolic function assessment. An E/e' ratio ≥ 15 after exercise is considered to indicate elevated LVFP-ex. A continuous diagnostic score of HFpEF was calculated on the basis of the European Society of Cardiology HFA-PEFF diagnostic algorithm.

RESULTS

LAS_reservoir was lowest in patients with elevated LVFP at rest (n = 81) and lower in those with normal resting filling pressure who developed elevated LVFP-ex (n = 108) compared with those who maintained normal LVFP-ex (29.0 ± 5.2% vs 33.1 ± 5.0% vs 39.3 ± 4.8%, P < .001). Lower LAS_reservoir was associated with worse exercise capacity as assessed by metabolic equivalents, exercise time, and functional aerobic capacity (multivariate-adjusted P values all < .05). In patients with normal or indeterminate LVFP at rest (n = 587), LAS_reservoir and preexercise HFA-PEFF score demonstrated areas under the curve of 0.82 and 0.7, respectively, for elevated LVFP-ex. There were 28% higher odds of developing elevated LVFP-ex per 1% decrease in LAS_reservoir (odds ratio, 0.78; 95% CI, 0.74-0.82). Among patients with intermediate scores (n = 461), 123 developed elevations in LVFP-ex and were classified as having HFpEF per the diagnostic algorithm. The addition of LAS_reservoir improved the diagnostic value of HFA-PEFF score for HFpEF (area under the curve increased from 0.71 to 0.80, P = .01).

CONCLUSIONS

LAS_reservoir has potential to identify patients with intermediate scores for HFpEF who may develop elevated LVFP-ex only and is therefore a promising alternative to aid in diagnosis when exercise testing is not feasible.

Patients with Diabetes and Significant Epicardial Coronary Artery Disease Have Increased Systolic Left Ventricular Apical Rotation and Rotation Rate at Rest

OBJECTIVE

The purpose of this study was to determine whether resting myocardial deformation and rotation may be altered in diabetic patients with significant epicardial coronary artery disease (CAD) with normal left ventricular ejection fraction.

DESIGN

A prospective observational study.

SETTING

Diagnosis of epicardial CAD in patients with diabetes.

PATIENTS AND METHODS

Eighty-four patients with diabetes suspected of epicardial CAD scheduled for cardiac catheterization had a resting echocardiogram performed prior to their procedure. Echocardiographic measurements were compared between patients with and without significant epicardial CAD as determined by cardiac catheterization.

MAIN OUTCOME MEASURES

Measurement of longitudinal strain, strain rate, apical rotation, and rotation rate, using speckle tracking echocardiography.

RESULTS

Eighty-four patients were studied, 39 (46.4%) of whom had significant epicardial CAD. Global peak systolic apical rotation was significantly increased (14.9 ± 5.1 vs. 11.0 ± 4.8 degrees, P < 0.001) in patients with epicardial CAD along with faster peak systolic apical rotation rate (90.4 ± 29 vs. 68.1 ± 22.2 degrees/sec, P < 0.001). These findings were further confirmed through multivariate logistic regression analysis (global peak systolic apical rotation OR = 1.17, P = 0.004 and peak systolic apical rotation rate OR = 1.05, P < 0.001).

CONCLUSIONS

Patients with diabetes with significant epicardial CAD and normal LVEF exhibit an increase in peak systolic apical counterclockwise rotation and rotation rate detected by echocardiography, suggesting that significant epicardial CAD and its associated myocardial effects in patients with diabetes may be detected noninvasively at rest.

Effect of Percutaneous Coronary Intervention on Left Ventricular Diastolic Function in Patients With Coronary Artery Disease

BACKGROUND

There is considerable disagreement over the effects of percutaneous coronary intervention (PCI) on left ventricular diastolic function that has necessitated the investigation of diastolic indices. The present study was conducted to evaluate left ventricular diastolic function and its indices, three months after performing the PCI procedure in patients with coronary artery disease (CAD).

METHODS

In a quasi-experimental clinical trial study (before and after), 51 patients with CAD scheduled for elective PCI were investigated provided that their Ejection Fraction (EF) was > 30%. Before and three months after PCI, echocardiography was carried out to evaluate left ventricular diastolic indices including the E/Ea as the most important criteria for diagnosis of diastolic heart failure (DHF).

RESULTS

Based on the E/Ea indices and after PCI, the number of patients with DHF decreased significantly: 40 patients (78.4%) before PCI versus 28 patients (54.9%) after PCI (p<0.05). The Mean and Standard error of deceleration time (DT), isovolumic relaxation time (IVRT), early diastolic mitral annulus velocity; Ea (E'), E/Ea and left ventricular ejection function (LVEF) indices underwent significant changes. In addition, MVA dur/PVA dur, PVs/PVd, and E/Ea indices had changed significantly after PCI in both genders. However, no significant difference was reported for the other indices.

CONCLUSION

The E/Ea ratio as an important criterion for diagnosis of DHF was improved after PCI. Improvement of several other diastolic indices was observed after the PCI procedure. It can be concluded that PCI can be an effective treatment modality in patients with left ventricular diastolic indices.

The effect of slow coronary flow on right and left ventricular performance

OBJECTIVE

To evaluate left and right ventricular functions using tissue Doppler echocardiography (TDE) and myocardial performance index (MPI) methods in patients with slow coronary flow (SCF) and to determine the relationship between these parameters and thrombolysis in myocardial infarction frame count in SCF patients.

SUBJECTS AND METHODS

Thirty-five patients (20 males and 15 females) with SCF who underwent coronary angiography and 35 age- and sex-matched controls (14 males and 21 females) without SCF who underwent elective coronary angiography were enrolled in the study. Left ventricular (LV) and right ventricular (RV) functions were examined using conventional echocardiography and TDE.

RESULTS

LV systolic myocardial velocity (Sm), early myocardial velocity (Em), late myocardial velocity (Am), and Em/Am ratio were similar in both the SCF and control groups; however, isovolumetric relaxation time (IRT) was higher in the SCF group compared to the control group (IRT: 99 ± 17 vs. 88 ± 20; p = 0.01). In patients with SCF, LV MPI was higher than in the control group, but this was not statistically significant (0.61 ± 0.11 vs. 0.56 ± 0.12; p = 0.07). The RV tricuspid annular velocities and MPI were similar in the SCF and control groups.

CONCLUSION

This study showed that SCF affected LV functions echocardiographically and could cause partially reduced LV performance. In addition, SCF did not affect RV functions echocardiographically.

Left atrial passive emptying function during dobutamine stress MR imaging is a predictor of cardiac events in patients with suspected myocardial ischemia

OBJECTIVES

The aim of this study was to determine the prognostic value of assessing left atrial function during dobutamine stress testing.

BACKGROUND

Left ventricular diastolic dysfunction precedes systolic wall motion abnormalities in the ischemic cascade. Severity of left ventricular diastolic function during cardiac stress is not characterized well by current clinical imaging protocols but may be an important prognostic factor. We hypothesized that abnormal early left atrial emptying measured during dobutamine stress cardiac magnetic resonance will reflect these diastolic changes and may be associated with cardiovascular outcomes.

METHODS

We enrolled 122 consecutive patients referred for dobutamine stress cardiac magnetic resonance for suspected myocardial ischemia. Left atrial volumes were retrospectively measured by the biplane area-length method at left ventricular end-systole (VOL(max)) and before atrial contraction (VOL(bac)). Left atrial passive emptying fraction defined by (VOL(max) - VOL(bac)) × 100%/VOL(max) and the absolute percent increase in left atrial passive emptying fraction during dobutamine stress (ΔLAPEF) were quantified.

RESULTS

Twenty-nine major adverse cardiac events (MACE) occurred during follow-up (median 23 months). By Kaplan-Meier analysis, patients with ΔLAPEF <10.8 (median) experienced higher incidence of MACE than did patients with a ΔLAPEF >10.8 (p = 0.004). By univariable analysis, ΔLAPEF was strongly associated with MACE (unadjusted hazard ratio for every 10% decrease = 1.56, p < 0.005). By multivariable analysis, every 10% decrease in ΔLAPEF carried a 57% increase in MACE, after adjustment to presence of myocardial ischemia and infarction.

CONCLUSIONS

Reduced augmentation of left atrial passive emptying fraction during dobutamine stress demonstrated strong association with MACE. We speculate that reduced left atrial passive emptying reserve during inotropic stress may represent underlying diastolic dysfunction and warrants further investigation.

Incremental value of subclinical left ventricular systolic dysfunction for the identification of patients with obstructive coronary artery disease

BACKGROUND

Left ventricular (LV) diastolic dysfunction and subclinical systolic dysfunction may be markers of coronary artery disease (CAD). However, whether these markers are useful for prediction of obstructive CAD is unknown.

METHODS

A total of 182 consecutive outpatients (54 +/- 10 years, 59% males) without known CAD and overt LV systolic dysfunction underwent 64-slice multislice computed tomography (MSCT) coronary angiography and echocardiography. The MSCT angiograms showing atherosclerosis were classified as showing obstructive (> or =50% luminal narrowing) CAD or not. Conventional echocardiographic parameters of LV systolic and diastolic function were obtained; in addition, (1) global longitudinal strain (GLS) and strain rate (indices of systolic function) and (2) global strain rate during the isovolumic relaxation period and during early diastolic filling (indices of diastolic function) were assessed using speckle-tracking echocardiography. In addition, the pretest likelihood of obstructive CAD was assessed using the Duke Clinical Score.

RESULTS

Based on MSCT, 32% of patients were classified as having no CAD, whereas 33% showed nonobstructive CAD and the remaining 35% had obstructive CAD. Multivariate analysis of clinical and echocardiographic characteristics showed that only high pretest likelihood of CAD (odds ratio [OR] 3.21, 95% 1.02-10.09, P = .046), diastolic dysfunction (OR 3.72, 95% CI 1.44-9.57, P = .006), and GLS (OR 1.97, 95% CI 1.43-2.71, P < .001) were associated with obstructive CAD. A value of GLS > or =-17.4 yielded high sensitivity and specificity in identifying patients with obstructive CAD (83% and 77%, respectively), providing a significant incremental value over pretest likelihood of CAD and diastolic dysfunction.

CONCLUSIONS

The GLS impairment aids detection of patients without overt LV systolic dysfunction having obstructive CAD.

Prognostic value of left atrial volume in patients who underwent dobutamine stress echocardiography for known or suspected coronary artery disease

BACKGROUND

Left atrial volume indexed (LAVI) has been reported as a predictor of cardiovascular events. We sought to determine the prognostic value of LAVI for predicting the outcome of patients who underwent dobutamine stress echocardiography (DSE) for known or suspected coronary artery disease (CAD).

METHODS

From January 2000 to July 2005, we studied 981 patients who underwent DSE and off-line measurements of LAVI. The value of DSE over clinical and LAVI data was examined using a stepwise log-rank test.

RESULTS

During a median follow-up of 24 months, 56 (6%) events occurred. By univariate analysis, predictors of events were male sex, diabetes mellitus, previous myocardial infarction, left ventricular ejection fraction (LVEF), left atrial diameter indexed, LAVI, and abnormal DSE. By multivariate analysis, independent predictors were LVEF (relative risk [RR] = 0.98, 95% CI 0.95-1.00), LAVI (RR = 1.04, 95% CI 1.02-1.05), and abnormal DSE (RR = 2.70, 95% CI 1.28-5.69). In an incremental multivariate model, LAVI was additional to clinical data for predicting events (chi(2) 36.8, P < .001). The addition of DSE to clinical and LAVI yielded incremental information (chi(2) 55.3, P < .001). The 3-year event-free survival in patients with normal DSE and LAVI < or =33 mL/m(2) was 96%; with abnormal DSE and LAVI < or =33 mL/m(2), 91%; with normal DSE and LAVI >34 mL/m(2), 83%; and with abnormal DSE and LAVI >34 mL/m(2), 51%.

CONCLUSION

Left atrial volume indexed provides independent prognostic information in patients who underwent DSE for known or suspected CAD. Among patients with normal DSE, those with larger LAVI had worse outcome, and among patients with abnormal DSE, LAVI was still predictive.

Clinical significance of diastolic function as an indicator of myocardial ischemia assessed by 16-frame gated myocardial perfusion SPECT

OBJECTIVE

Studies have suggested that ischemia-induced diastolic dysfunction persists longer than systolic dysfunction. We examined whether global left ventricular (LV) diastolic function during stress testing assessed by 16-frame gated myocardial perfusion single-photon emission computed tomography (SPECT) is useful as an indicator of myocardial ischemia.

METHODS

Thirty-nine patients underwent 16-frame technetium-99m (Tc-99m) quantitative gated SPECT (QGS), including treadmill exercise testing for suspected ischemic heart disease. Diastolic parameters of the first-third filling fraction (1/3FF), and the peak filling rate (PFR) were calculated by a time-volume curve from the QGS data.

RESULTS

The patients were divided into four groups, namely, IS, NL, DN, and DD, on the basis of tracer accumulation and the LV ejection fraction (LVEF) at rest. In the IS group (reversible tracer uptake reduction suggesting ischemia; n=11), LVEF, 1/3FF, and PFR after stress were significantly lower than those at rest, whereas in the NL group (normal perfusion; n=10) and DN group (fixed tracer uptake reduction with normal systolic function; EF>or=60% at rest; n=10), LVEF, 1/3FF, and PFR after stress did not differ from those at rest. However, in the DD group (fixed tracer uptake reduction with cardiac dysfunction; EF<60%, average 47.1%; n=8), LVEF, 1/3FF, and PFR were significantly altered after stress.

CONCLUSIONS

Altered global LV diastolic function during stress assessed by 16-frame gated myocardial perfusion SPECT is useful for the detection of myocardial ischemia. However, similar findings are observed in patients with cardiac dysfunction but without detectable ischemia. Our findings do suggest that tests should be performed with caution to determine whether ischemia exists on the basis of altered global LV function after stress in patients with cardiac dysfunction.

Improved regional myocardial diastolic function assessed by strain rate imaging in patients with coronary artery disease undergoing percutaneous coronary intervention

This study investigated the effects of percutaneous coronary intervention (PCI) on global and regional left ventricular diastolic function, as assessed by strain rate (SR) imaging. In 27 patients with coronary artery disease, we performed echocardiography before and after PCI to obtain segmental peak systolic SR and peak early diastolic SR (E(SR)). PCI did not significantly change peak systolic SR in the ischemic (1.59 +/- 0.59-1.66 +/- 0.52/s) and nonischemic (1.64 +/- 0.59-1.61 +/- 0.53/s) segments. E(SR) in the ischemic segments was significantly smaller than that in the nonischemic segments at rest (1.82 +/- 0.71 vs 2.03 +/- 0.64/s, P < .01). PCI caused a significant increase in E(SR) from 1.82 +/- 0.71 to 2.29 +/- 0.92/s in the ischemic (P < .001), but not in the nonischemic, segments. The peak early diastolic transmitral flow velocities after PCI were improved in patients with greater extent of improvement of E(SR) in the ischemic segments. These findings suggest that the improvement in left ventricular early diastolic filling after PCI may be associated with the degree of improvement in impaired regional myocardial relaxation.

Comparison of gated blood pool SPECT and multi-detector row computed tomography for measurements of left ventricular volumes and ejection fraction in patients with atypical chest pain: validation with radionuclide ventriculography

Gated blood pool SPECT (GBPS) is an alternative to planar radionuclide ventriculography (PRNV) and offers potential advantages. The aim of this study was to compare GBPS, multi-row detector spiral computed tomography (MDCT), and PRNV for the determination of left ventricular ejection fraction (LVEF) and left ventricular volumes (LV) in subjects with atypical chest pain.

METHOD

Twenty-three consecutive patients (14 men, 9 women; mean age 56.2 +/- 9.5 years) referred for MDCT for evaluation of atypical chest pain. All patients underwent PRNV, GBPS, and MDCT at the same day.

RESULTS

The mean LVEFs calculated with PRNA (57.3 +/- 8.6%), GBPS (55.2 +/- 6.6%), and MDCT (56 +/- 9.1%) were not statistically different (F value 0.3374, p = 0.715). Comparison of LVEFs from GBPS and MDCT yielded correlation coefficients of 0.5238 (p = 0.0178, 95% CI = 0.1057-0.7845). The correlation of LVEFs between GBPS and PRNV showed a correlation coefficient of 0.8073 (p < 0.0001, 95% CI = 0.5676-0.9209) and 0.6190 (p = 0.0036, 95% CI = 0.2431-0.8333) between MDCT and PRNV. The mean LV end-diastolic volume (EDV) calculated with GBPS (82.7 +/- 17.5 ml) was significantly lower than MDCT (106.8 +/- 18.5 ml) (p = 0.0001). The mean LV end-systolic volume (ESV) calculated with GBPS (37.2 +/- 9.6 ml) was also significantly lower than MDCT (48.1 +/- 15.8 ml) (p = 0.012). Comparison of EDV from GBPS and MDCT yielded a correlation coefficient of 0.5220 (p = 0.0182, 95% CI = 0.1033-0.7835). The correlation of ESV between GBPS and MDCT showed a correlation coefficient of 0.6642 (p = 0.0014, 95% CI = 0.3140-0.8553).

CONCLUSION

In conclusion, the LVEF, EDV, and ESV calculated by GBPS correlated significantly with those of obtained with 16-MDCT. In addition, there were no statistical differences of LVEF calculated from PRNV, GBPS, and MDCT. However, with regard to LV, EDV and ESV from GBPS revealed statistically significantly lower than those of MDCT. Also, these results should be addressed whether similar results could also be found in patients with cardiac diseases by the consequent larger population-based study.

Predictive Value of Normal Left Atrial Volume in Stress Echocardiography

OBJECTIVES

Our objective was to evaluate whether normal left atrial volume index (LAVI) is a predictor of a normal stress echocardiogram and thus a predictor of low ischemic risk.

BACKGROUND

Left atrial enlargement is closely related to the chronicity and intensity of the burden of increased ventricular filling pressure. Typically ischemic heart disease (IHD) has a long period of subclinical dysfunction. Increased filling pressure, reflected by enlarged LAVI, is hypothesized to mirror the burden of subclinical and overt IHD. We hypothesized that a normal LAVI might also be useful in predicting low IHD risk.

METHODS

One hundred eighty randomly selected patients (mean age, 63 +/- 15 years; 53% men) underwent outpatient exercise or dobutamine stress echocardiography for known or suspected coronary artery disease. Left atrial volume index was measured retrospectively with the biplane area-length method. The stress echocardiogram was interpreted as abnormal if wall motion abnormalities (WMAs) were noted at rest and/or with stress.

RESULTS

Left atrial volume index was categorized as < or =28 ml/m2 (normal), 28.1 to 32 ml/m2, 32.1 to 36 ml/m2, and >36 ml/m2. Abnormal stress echocardiography was identified in 57 patients (31.7%). The percentage of abnormal stress echocardiograms in each LAVI category was 5.7%, 21.9%, 38.7%, and 54.7%, respectively. The negative predictive value for LAVI < or =28 ml/m2 was 94.3%.

CONCLUSIONS

Normal resting LAVI (< or =28 ml/m2) was strongly predictive of a normal stress echocardiogram. Left atrial volume index might be a simple means of identifying patients with low ischemic risk and should be further evaluated as a complement to the assessment of ischemic risk.

Gated blood pool SPECT for measurement of left ventricular volumes and left ventricular ejection fraction: comparison of 8 and 16 frame gated blood pool SPECT

Gated blood pool SPECT (GBPS) is an alternative to planar radionuclide ventriculography (PRNV) and offers potential advantages. The aim of this study was to compare 8 and 16 frame GBPS for the determination of left ventricular ejection fraction(LVEF) and left ventricular volumes (LV) in subjects underwent two consecutive GBPS.

METHOD

About 66 consecutive patients (30 men, 36 women; mean age 62.3 +/- 10.4 years) referred for PRNV for evaluation of preoperative cardiac risk stratification (n = 40), prechemotherapy cardiac function evaluation (n = 18, breast cancer), and congestive heart failure patients (n = 8). All patients underwent PRNV of 16 frame and GBPS with both of 8 and 16 frame.

RESULTS

The mean LVEF calculated with PRNV (58.3 +/- 16.8), showed statistically lower than 8-GBPS (70.6 +/- 17.7), and 16-GBPS (69.9 +/- 16.8) (PRNV vs. 8-GBPS, p < 0.01; PRNV vs 16-GBPS, p < 0.01; 8-GBPS vs 16-GBPS, p > 0.05). The correlation of LVEFS between 8-GBPS and 16-GBPS showed a correlation coefficient of 0.9194 (p < 0.01, 95% CI = 0.8712-0.9500). The mean left ventricular end-diastolic volumes (EDV) calculated with 8-GBPS (83.2 +/- 33.5 ml), and 16-GBPS (88.4 +/- 36.8 ml) showed no statistical differences (p > 0.05). The mean left ventricular end-systolic volumes (ESV) calculated with 8-GBPS (28.1 +/- 31.4 ml), and 16-GBPS (30.5 +/- 33 ml) showed also no statistical differences (p > 0.05). Comparison of EDV from 8 and 16-GBPS yielded a correlation coefficient of 0.7430 (p < 0.01, 95% CI = 0.6108-0.8349). The correlation between ESV of 8-GBPS and 16-GBPS showed a correlation coefficient of 0.9522 (p < 0.01, 95% CI = 0.9228-0.9705).

CONCLUSION

This study demonstrated that the LVEFs of 8-GBPS correlated well with that of 16-GBPS. The LVEF of PRNV was significantly lower than those of 8 and 16-GBPS. Also, left ventricular EDV and ESV of 8-GBPS correlated well with those of 16-GBPS. Also, further studies, involving large lumber patients, should be performed to validate the usefulness of GBPS for the evaluation of left ventricular diastolic function.

Effects of Postischemic Regional Left Ventricular Diastolic Wall Motion Abnormalities or Delayed Relaxation Following Coronary Vasospasm on Global Diastolic Function

BACKGROUND

Regional left ventricular (LV) diastolic wall motion abnormalities detected by color kinesis (CK), an echocardiographic technique, may be a more sensitive measure to postischemic damage following coronary spasm than parameters of global diastolic function.

METHODS AND RESULTS

Regional LV diastolic wall motion was evaluated by using CK in 18 patients with variant angina on the day following coronary spasm, which was induced by intracoronary acetylcholine. Fractional regional LV cavity area expansion in the short-axis view during the first 30% of the LV filling time, was used to identify postischemic asynchronous diastolic wall motion. Regional delayed relaxation was observed in any of the LV regions in all the patients, who were divided into 2 groups (Group S: 7 patients with single-vessel spasm with regional delayed relaxation in one area. Group M: 11 patients with multivessel spasm or spasm of the proximal left anterior descending branch with regional delayed relaxation in multiple areas). In Group S, no abnormality (0%) was noted in any of the indexes of global diastolic function including the isovolumic relaxation time, the ratio of peak rapid filling to peak atrial filling velocities and the deceleration time. In contrast, in 5 (45%) of the Group M patients, abnormalities were noted in all of those indexes.

CONCLUSIONS

Postischemic regional LV-delayed relaxation following coronary vasospasm was detected sensitively by analysis of CK images. The indexes of global LV diastolic function are insensitive to postischemic damage following single vessel spasm, although they are somewhat sensitive following multivessel spasm.

Diagnosis of multivessel coronary vasospasm by detecting postischemic regional left ventricular delayed relaxation on echocardiography using color kinesis

BACKGROUND

It is not known whether multivessel coronary spasm occurs spontaneously in patients who have variant angina (VA) with demonstrated multivessel spasm induced by intracoronary injection of acetylcholine (ACh). Regional left ventricular (LV) diastolic dysfunction or wall motion abnormality may persist after an episode of coronary vasospasm. Color kinesis (CK) is a recent development that facilitates the echocardiographic evaluation of regional diastolic wall motion.

METHODS AND RESULTS

Regional diastolic wall motion was evaluated using CK in 26 patients with VA within 1 week of the last episode of angina. The LV segmental filling fraction in the short-axis view during the first 30% of the diastolic filling time, expressed as a percentage, was used to objectively identify postischemic diastolic endocardial motion asynchrony. Diastolic asynchrony or regional LV delayed relaxation was noted in all 26 (100%) patients and in 14 (54%) it was detected in multiple vascular territories, suggesting multivessel spasm. Multivessel spasm was induced by ACh in 11 (79%) of the patients with suspected multivessel spasm by CK. In 11 (92%) of the 12 patients with multivessel spasm induced by ACh multiple regions of delayed relaxation had been noted by CK. The regions of delayed relaxation were largely consistent with the territories perfused by the arteries reacting to ACh (sensitivity: 96%, specificity: 91%).

CONCLUSION

ACh induced spasm in the same coronary arteries as those perfusing the regions with delayed diastolic wall motion detected by CK in most of the patients with VA, suggesting that multivessel spasm does occur spontaneously in patients with susceptible arteries.

Association of plasma atrial natriuretic peptide, N-terminal proatrial natriuretic peptide, and brain natriuretic peptide levels with coronary artery stenosis in patients with normal left ventricular systolic function

PURPOSE

To examine whether coronary artery stenosis affects plasma levels of atrial natriuretic peptide (ANP), N-terminal proatrial natriuretic peptide (proANP), and brain natriuretic peptide (BNP) in patients with normal left ventricular systolic function.

METHODS

We studied 104 consecutive patients with normal left ventricular function and suspected coronary artery stenosis. Plasma natriuretic peptide levels were measured by immunoradiometric assays.

RESULTS

Plasma levels of ANP, N-terminal proANP, and BNP were higher in patients with (n = 65) than in those without (n = 39) coronary artery stenosis, whereas hemodynamic variables were similar. Patients who had coronary artery stenosis with only distal lesions (n = 36) had higher levels of all three natriuretic peptides than did patients with no coronary artery stenosis. N-terminal proANP levels were significantly higher in patients who had coronary artery stenosis with proximal lesions (n = 29) than in patients who had coronary artery stenosis with only distal lesions and those with no coronary artery stenosis. Multiple logistic regression analysis revealed that N-terminal proANP, but not ANP or BNP, was independently associated with coronary artery stenosis after adjusting for clinical and demographic variables (odds ratio per 100 fmol/mL increase = 1.9; 95% confidence interval: 1.9 to 2.6; P = 0.01). However, the sensitivity, specificity, and positive and negative predictive values of each peptide were not sufficiently high to be used for prediction.

CONCLUSION

N-terminal proANP may be associated with clinically important coronary artery stenosis in patients with normal left ventricular systolic function, but its clinical usefulness may be limited.

Left atrial volume as a morphophysiologic expression of left ventricular diastolic dysfunction and relation to cardiovascular risk burden

Left ventricular (LV) diastolic dysfunction is prevalent in the community. Current assessment of diastolic function can be complex, involving Doppler evaluation of an array of hemodynamic data. The relation between left atrial (LA) volume and diastolic function, and between LA volume and cardiovascular risk and disease burden are not well known. In the present prospective study of 140 adults, mean age 58 +/- 19 years, referred for a clinically-indicated echocardiogram and in sinus rhythm, with no history of atrial arrhythmias or valvular heart disease, we determined the LA volume, LV diastolic function status, cardiovascular risk score (based on age, gender, history of systemic hypertension, diabetes mellitus, hyperlipidemia, and smoking), and cardiovascular disease burden (based on confirmed vascular disease, congestive heart failure, and transient ischemic attack or stroke). LA volume was found to correlate positively with age, body surface area, cardiovascular risk score, LV end-diastolic and end-systolic dimensions, LV mass, diastolic function grade, tissue Doppler E/E', tricuspid regurgitation velocity, and negatively with LV ejection fraction (all p <0.006). In a multivariate clinical model, LA volume indexed to body surface area (indexed LA volume) was independently associated with cardiovascular risk score (p <0.001), congestive heart failure (p = 0.014), vascular disease (p = 0.012), transient ischemic attack or stroke (p = 0.021), and history of smoking (p = 0.008). In a clinical and echocardiographic model, indexed LA volume was strongly associated with diastolic function grade (p <0.001), independent of LV ejection fraction, age, gender, and cardiovascular risk score. In patients without a history of atrial arrhythmias or valvular heart disease, LA volume expressed the severity of diastolic dysfunction and provided an index of cardiovascular risk and disease burden.

Are ejection fractions from gated SPECT perfusion studies clinically useful? A comparison with radionuclide ventriculography

Gated SPECT (GSPECT) was evaluated for the measurement of left ventricular ejection fraction (LVEF) by comparing with equilibrium gated radionuclide ventriculography (RNVG). A total of 99 subjects underwent GSPECT and RNVG imaging. All studies were acquired in list mode with GSPECT studies processed to give 16- and 8-frames per R-R interval, and RNVG studies 24 frames per R-R interval. The Cedars-Sinai QGS software was used to calculate ejection fraction from GSPECT studies. RNVG studies were processed using a manually drawn single region of interest technique. Comparison of LVEF from GSPECT with RNVG yielded correlation coefficients of 0.82 and 0.81 for 16- and 8-frame GSPECT studies respectively. The mean 95% prediction interval was 33 +/- 11 percentage points for both 16- and 8-frame studies, indicating a great disparity between predicted ejection fraction values from GSPECT and actual RNVG values. Subgroup analysis of 29 patients with pathological Q-wave evidence of myocardial infarction demonstrated a poorer correlation coefficient of r = 0.69. Subgroup analysis of 32 patients with end-diastolic volumes < 100 ml demonstrated a poorer correlation coefficient of r = 0.32. Ejection fractions calculated from 16- and 8-frame studies showed a correlation of 0.99 with a mean 95% prediction interval of 8.7 +/- 0.04 percentage points. The 8-frame studies underestimated LVEF by 3.6 +/- 2.3% compared to the 16-frame studies. In conclusion, left ventricular ejection fractions calculated using the QGS algorithm from GSPECT studies are inadequate for use in clinical practice.

Enhanced external counterpulsation improves exercise tolerance, reduces exercise-induced myocardial ischemia and improves left ventricular diastolic filling in patients with coronary artery disease

OBJECTIVES

We examined whether enhanced external counterpulsation (EECP) improves myocardial ischemia, exercise tolerance and cardiac function in patients with coronary artery disease (CAD).

BACKGROUND

Enhanced external counterpulsation reduces angina and improves exercise tolerance in patients with CAD. Some objective improvements of ischemia by EECP have been reported, but they should be confirmed further. Detailed hemodynamic effects of EECP have been less well documented.

METHODS

Enhanced external counterpulsation was performed for a total of 35 h in patients with stable CAD (n = 12) who showed evidence of exercise-induced myocardial ischemia despite conventional medical or surgical therapies. All patients had significant stenotic lesions in major coronary arteries.

RESULTS

Enhanced external counterpulsation improved all exercise test parameters (p < 0.05): exercise duration, time to 1-mm ST segment depression, rate-pressure product at peak exercise and rate-pressure product at 1-mm ST segment depression. Moreover, the prevalence of exercise-induced reversible perfusion defects by thallium scintigraphy decreased after treatment (p < 0.01). Enhanced external counterpulsation did not alter systolic function but improved diastolic filling, left ventricular (LV) end-diastolic pressure (p < 0.05) by cardiac catheterization and LV peak filling rate end-diastolic volume/s (p < 0.01) and time to peak filling rate (p < 0.05) by radionuclide scintigraphy. These hemodynamic improvements were associated with decreased plasma brain natriuretic peptides levels after EECP (p < 0.05).

CONCLUSIONS

Thus, EECP treatment improves exercise tolerance and reduced myocardial ischemia by thallium scintigraphy in association with improved LV diastolic filling in patients with stable CAD.

Myogenic cell transplantation improves in vivo regional performance in infarcted rabbit myocardium

BACKGROUND

Although cardiac transplantation is an ideal treatment for end-stage heart disease, inadequate donor availability has stimulated efforts to manage terminally injured myocardium by other innovative methods. Autologous skeletal myoblast transplantation, or cellular cardiomyoplasty, is one method to potentially mediate myocardial repair within chronically injured hearts. However, few investigators have documented the ability of myogenic cells to alter load-insensitive indices of systolic and diastolic performance in vivo. In this study, both systolic and diastolic regional myocardial function were evaluated following left ventricular cryoinjury and compared with function after myogenic cell transplantation.

METHODS

Left ventricular pressure and segment length were determined in 9 rabbits by micromanometry and sonomicrometry 1 week following cryoinjury and 3 weeks after myoblast transplantation. At study termination, the extent of myoblast engraftment was determined by histologic analysis. Systolic performance was based on the linear regression of stroke work and end-diastolic segment length. Diastolic properties were evaluated by the curvilinear relationships between left ventricular pressure and strain, and left ventricular pressure and end-diastolic segment length.

RESULTS

Although mean indices of systolic performance were unchanged after cell transplantation, systolic performance improved in 3 animals. In contrast, myoblast engraftment was associated with significantly improved diastolic properties (strain and dynamic stiffness) in all animals.

CONCLUSIONS

These data quantify temporal changes in regional myocardial performance and suggest that cellular cardiomyoplasty improves diastolic compliance prior to affecting systolic performance. Cellular cardiomyoplasty, a potential therapeutic option for ischemic heart disease, appears to reverse diastolic creep and thus may represent a clinical alternative to transplantation in the near future.

Cellular cardiomyoplasty improves diastolic properties of injured heart

BACKGROUND

Acute myocardial infarction leads to loss of functional myocytes and structural integrity that often decreases diastolic compliance and increases resting myocardial segment length (diastolic creep). Successfully engrafting autologous skeletal myoblasts could improve compliance and potentially reverse creep. Thus, we transplanted myoblasts into cryoinjured rabbit heart (n = 15, CRYO) and measured regional diastolic properties in the presence (n = 9, +ENG) or absence (n = 6, -ENG) of engraftment.

MATERIALS AND METHODS

Left ventricular (LV) pressures (P) and myocardial segment lengths (SL) were measured in vivo by micromanometry and sonomicrometry after cryoinjury (CRYO) and again 3 weeks following transplantation of myoblasts. Performance was estimated from the relationships between end-diastolic (ED) P and strain (epsilon) or between EDP and EDSL. Compliance was characterized by strain (epsilon(8)) and dynamic stiffness (dP/dL(8)) at 8 mm Hg. Creep was characterized by resting myocardial segment length (EDSL(0)) and static stiffness at 8 mm Hg (m(stat8)).

RESULTS

Successful myoblast engraftment was determined via histologic examination. In nine +ENG animals, diastolic properties improved. Regional strain (epsilon(8)) increased (0.06 +/- 0.02 CRYO vs 0.10 +/- 0.04 +ENG; P = 0.0009) while dynamic stiffness (dP/dL(8)) decreased (43 +/- 23 mm Hg/mm CRYO vs 23 +/- 14 mm Hg/mm +ENG; P = 0.009). Static stiffness (m(stat8)) was unaffected (0.78 +/- 0.2 mm Hg/mm CRYO vs 0.72 +/- 0. 1 mm Hg/mm +ENG; P = 0.08), and creep did not occur (EDSL(0) = 10.3 +/- 2.8 CRYO vs 10.4 +/- 2.3 +ENG; P = 0.74). In the absence of myoblast engraftment (n = 6, -ENG), strain decreased (epsilon(8) = 0. 06 +/- 0.02 CRYO vs 0.05 +/- 0.02 -ENG; P = 0.048), but dynamic stiffness (dP/dL(8)) did not (36 +/- 19 mm Hg/mm CRYO vs 28 +/- 12 mm Hg/mm -ENG; P = 0.20). Furthermore, static stiffness decreased (0. 78 +/- 0.3 mm Hg/mm CRYO vs 0.65 +/- 0.2 mm Hg/mm -ENG; P = 0.05) and creep was obvious (EDSL(0) = 10.8 +/- 3.6 mm CRYO vs 13.0 +/- 4. 4 mm -ENG, P = 0.04).

CONCLUSIONS

Myoblast engraftment may partially overcome the loss of myocytes and structural integrity that often follow chronic myocardial ischemia. Improved compliance and reversal of diastolic creep suggest regeneration of viable muscle within once infarcted myocardium.

N-terminal proatrial natriuretic peptide in angina pectoris: impact of revascularization by angioplasty

AIMS

We investigated whether levels of N-terminal proatrial natriuretic peptide (N-terminal proANP) reflect the severity of coronary artery disease in chronic, stable angina pectoris. Furthermore, we investigated if revascularization by percutaneous transluminal coronary angioplasty (PTCA) affected the N-terminal proANP level and, finally, whether restenosis could be predicted by changes in N-terminal proANP after PTCA.

METHODS AND RESULTS

N-terminal proANP was measured in 286 patients before and after PTCA. The patients' baseline level of N-terminal proANP (787+/-403 pmol/l) correlated significantly with left ventricular end diastolic pressure, age and serum creatinine, but not with the number of stenotic vessels. Twenty-four hours post-PTCA N-terminal proANP decreased significantly, and completely revascularized patients demonstrated a decline two-fold larger than those incompletely revascularized (deltaN-terminal proANP -114+/-178 vs. -53+/-231 pmol/l, P<0.05). After 14 days N-terminal proANP had returned to baseline in both groups. Changes in N-terminal proANP from post-PTCA to the final follow-up was not predictive of angiographic restenosis.

INTERPRETATION

The significant decrease in N-terminal proANP observed after angioplasty, most pronounced in patients completely revascularized, is thought to reflect a transient improvement in resting left ventricular function.

Diastolic heart failure: standard Doppler approach and beyond

Evidence of normal systolic left ventricular function has been reported in up to 30-40% of patients with clinical signs of congestive heart failure, suggesting that diastolic dysfunction is an important predictor of prognosis and mortality. Doppler echocardiography as a noninvasive diagnostic procedure is able to provide immediate and relevant information on functional and structural changes underlying the clinical syndrome of heart failure. Four distinct early filling/late diastole (E/A) ratio patterns (normal, delayed relaxation, pseudonormal, restrictive) can be discerned if viewed within the context of other available clinical information. These patterns evolve from one to another in a single individual, with changes in disease evolution, treatment, and loading condition. They represent a continuum from normal to severe diastolic dysfunction, showing progressively increasing left ventricular (LV) chamber stiffness and subsequently decreasing deceleration time. The combination of Doppler restrictive filling pattern and decreased deceleration time provides important information that helps to differentiate gradations of diastolic dysfunction and has been found to be a potent predictor of prognosis and mortality in various cardiac conditions. When clinical and transthoracic data alone are not sufficient in guiding therapy of congestive heart failure, transesophageal echocardiography can be used to assess most Doppler flows, especially pulmonary venous and left atrial (LA) appendage flows. The use of the multiplane transducer in multiple intermediate scan planes further improves the possibility of optimizing the Doppler incident angle and obtaining the best Doppler recordings of the left upper or right upper pulmonary venous flow. Whereas LV diastolic dysfunction is common in patients with congestive heart failure and appears to be an important predictor of prognosis, little information is available about right ventricular (RV) diastolic dysfunction. The role of RV function in congestive heart failure has probably been underestimated and it is possible that RV diastolic dysfunction assessment is equally important in the follow-up of heart failure patients. Recently, 2 novel echocardiographic technologies for the assessment of ventricular wall dynamics have been developed--color kinesis and tissue Doppler imaging. Both techniques have recently been shown to provide global as well as regional information on LV contraction and filling. Complementary use of both techniques may allow a more complete noninvasive assessment of global and regional systo-diastolic LV function.

Nitrate administration to enhance the detection of myocardial viability by technetium-99m tetrofosmin single-photon emission tomography

A comparison was performed between technetium-99m tetrofosmin myocardial perfusion tomography at baseline and after nitrate administration, using a 2-day protocol, and rest-reinjection thallium-201 single-photon emission tomography (SPET) studies in order to assess whether nitrates enhance the detection of viable myocardium with 99mTc-tetrofosmin. Fifteen patients with coronary artery disease, previous myocardial infarction and a left ventricular ejection fraction <40% underwent 201Tl rest-injection and 99mTc-tetrofosmin baseline-postnitroglycerin (0.4 mg sublingually) SPET studies, within 48 h. Tomograms based on the three spatial planes were divided into 15 segments and regional tracer uptake was quantitatively analysed. Viability was defined as presence of tracer uptake >/=50% of peak activity on baseline studies or after reversibility. The percentage of peak activity of 99mTc-tetrofosmin at baseline correlated with that of 201Tl (r=0.82, P <0.001). On baseline 99mTc-tetrofosmin studies, 73 of the 225 segments that were analysed had <50% of peak activity. Fifteen percent of these segments showed reversibility after nitrate administration, with an increase in 99mTc-tetrofosmin uptake from 40%+/-9% to 57%+/-9% of peak activity (P=0.003). All reversible segments after nitrate administration had viability criteria on 201Tl studies, but 20 segments that were non-viable on 99mTc-tetrofosmin studies were viable on 201Tl studies. Using a threshold value of >/=40% of peak activity, only seven segments remained non-viable on 99mTc-tetrofosmin studies. Overall agreement between 99mTc-tetrofosmin with nitrates and 201Tl-reinjection regarding the presence of myocardial viability was 90%. Detection of myocardial viability with 99mTc-tetrofosmin was enhanced after nitrate administration, correlating with viability criteria observed on thallium studies.

Impaired left ventricular diastolic filling occurs in diabetic patients without atherosclerotic coronary artery disease

Using left ventriculography, left ventricular diastolic function was studied in 24 diabetic patients who had angina pectoris without atherosclerotic large-vessel coronary artery diseases (group A, 14 patients with exercise-induced ischemic ST-T changes as seen during electrocardiogram; group B, 10 patients without such changes). In groups A and B, the global peak filling rate was significantly less than that in control patients without diabetes or cardiac diseases. The ratio of the global time to the peak filling rate to the diastolic time was higher in both groups A and B than in the control groups. However, the total of time differences, defined as the sum of the time differences between global time to the peak filling rate and each of the three regional time to the peak filling rate, was greater in group A than in either group B or the control patients. Total time difference was similar in group B and the controls. Left ventricular diastolic filling was impaired in diabetic patients without large-vessel coronary artery disease. Impaired diastolic filling was present regionally in patients with ischemic ST-T change but globally in those without such change.

Myocardial material property determination in the in vivo heart using magnetic resonance imaging

OBJECTIVES

To determine nonlinear material properties of passive, diastolic myocardium using magnetic resonance imaging (MRI) tissue-tagging, finite element analysis (FEA) and nonlinear optimization.

BACKGROUND

Alterations in the diastolic material properties of myocardium may pre-date the onset of or exist exclusive of systolic ventricular dysfunction in disease states such as hypertrophy and heart failure. Accordingly, significant effort has been expended recently to characterize the material properties of myocardium in diastole. The present study defines a new technique for determining material properties of passive myocardium using finite element (FE) models of the heart, MRI tissue-tagging and nonlinear optimization. This material parameter estimation algorithm is employed to estimate nonlinear material parameter sin the in vivo canine heart and provides the necessary framework to study the full complexities of myocardial material behavior in health and disease.

METHODS AND RESULTS

Material parameters for a proposed exponential strain energy function were determined by minimizing the least squares difference between FE model-predicted and MRI-measured diastolic strains. Six mongrel dogs underwent MRI imaging with radiofrequency (RF) tissue-tagging. Two-dimensional diastolic strains were measured from the deformations of the MRI tag lines. Finite element models were constructed from early diastolic images and were loaded with the mean early to late left ventricular and right ventricular diastolic change in pressure measured at the time of imaging. A nonlinear optimization algorithm was employed to solve the least squares objective function for hte material parameters. Average material parameters for the six dogs were E = 28,722 +/- 15984 dynes/cm2 and c = 0.00182 +/- 0.00232 cm2/dyne.

CONCLUSION

This parameter estimation algorithm provides the necessary framework for estimating the nonlinear, anisotropic and non-homogeneous material properties of passive myocardium in health and disease in the in vivo beating heart.

Effect of mibefradil on left ventricular diastolic function in patients with congestive heart failure

Calcium antagonists have antihypertensive and antianginal properties. In heart failure, however, their use can be hazardous, as systolic function can deteriorate. This may not be true of the new calcium antagonist mibefradil, which has a new chemical structure. Calcium antagonists may also be beneficial for diastolic left ventricular function in coronary artery disease. To investigate the possible effects of mibefradil on diastolic left ventricular function, we performed the present study as a multicenter, double-blind,placebo-controlled, multiple-dose safety trial. Fifteen patients with New York Heart Association (NYHA) class II or III for dyspnea and depressed ejection fraction (<40%) due to a previous myocardial infarction were investigated. The measured nuclear angiographic parameters included ejection fraction (EF), peak ejection rate (PER), and peak filling rate (PFR). Systolic and diastolic blood pressure (SBP, DBP) and heart rate (HR) were also obtained. Group I (5 patients) received placebo medication; group IIA (6 patients) received mibefradil 6.25, 12.5, or 25 mg/day; and group IIB (4 patients) received mibefradil 50 or 100 mg/day. Measurements were made before and after the first dose and after 1 week of treatment before and after the final dose. Mibefradil clearly decreased HR (repeated-measures analysis of variance p < 0.05). No statistically significant effects of mibefradil were noted on SBP or DBP or on systolic and diastolic left ventricular function. In our study conditions, mibefradil caused no worsening of systolic function and preserved diastolic function in short-term treatment of patients with decreased EF and heart failure.

[Congestive heart failure in the elderly. Value of Doppler echocardiography]

Fifty-eight consecutive elderly patients (seven men and 51 women, mean age 84 +/- 6) admitted for congestive heart failure were prospectively investigated by doppler echocardiography in order to 1) define the prevalence of cardiac failure with normal left ventricular systolic function, 2) estimate the role of abnormalities of left ventricular filling (diastolic dysfunction), 3) evaluate echodoppler parameters for assessment of diastolic function: ratio of early peak on atrial peak of filling velocities (E/A), mitral deceleration time (MDT) and isovolumic relaxation time (IRT). Of the 58 patients, 32 (55%) had normal left ventricular systolic function and 26 (45%) had systolic dysfunction. Of the 32 patients with normal systolic function, diastolic function could not be evaluated in nine patients, was abnormal in 16 and normal in seven. Congestive heart failure with normal systolic function is very frequent in the elderly subject. Sensitivity of clinical data being too low, doppler echocardiography is the easiest noninvasive technique for defining abnormalities of both left ventricular systolic and diastolic function. In the elderly, MDT and IRT are more sensitive parameters than E/A for the diagnosis of diastolic dysfunction.

Ventricular gradient variability. New ECG method for detection of ischemic heart disease

The usefulness of ventricular gradient variability for detecting the presence of ischemic heart disease was evaluated in 38 patients with coronary artery disease (group 1), 21 patients with chest pain and no coronary artery disease (group 2), and 33 healthy control subjects. The ventricular gradient of each consecutive heartbeat at rest over a 22-second interval was calculated using a microcomputer. The SD and coefficient of variation for azimuth, elevation, and magnitude were used as indices of ventricular gradient variability. The SD and coefficient of variation of both the magnitude and elevation of ventricular gradient in group 1 were significantly greater than those of the other two groups (P < .01, respectively). When the normal upper limit was defined as 2SD above the mean value in the control group, a comparison between the findings for group 1 and group 2 revealed that the coefficient of variation of magnitude of the ventricular gradient was the most sensitive (82%) and specific (91%) index for coronary artery disease (chi-square test, P < .001). This study suggests that the variability in the magnitude of the ventricular gradient is a reliable index of ischemic heart disease.

Preimplantation echo Doppler evaluation of VVI versus DDD pacing

This study was carried out to select before permanent pacemaker implantation patients with complete atrioventricular block (CHB) who would benefit best from DDD pacing, and to determine the optimal atrioventricular delay (AVD) for each of those patients. This was achieved with the aid of Doppler echocardiography. The effect of different AVDs on both the systolic and diastolic function of the normal and failing heart was also delineated in this study.

METHODS

Thirty patients with CHB and normal sinoatrial function were selected, with no age or sex predilection. These patients were categorized into three equal groups: groups A, B, and C with normal left ventricular (LV) systolic and diastolic function, LV diastolic dysfunction, and LV systolic dysfunction, respectively. For each patient, systolic and diastolic function was calculated utilizing echo Doppler during CHB, temporary VDD pacing with different AVDs, and temporary VVI pacing with a rate matching that during VDD mode. Temporary VDD mode of pacing was performed utilizing a temporary bipolar ventricular lead for ventricular pacing and an esophageal lead for atrial sensing to trigger ventricular pacing.

RESULTS

Qualitatively the most obvious change in the pattern of LV filling as AVD is increased in the three groups, is the earlier occurrence of active atrial filling A wave due to progressive approximation of the ECG P wave toward the previous QRS. As the AV interval is increased, the following changes occur: (a) A wave occurs progressively earlier with superimposition onto the early filling E wave resulting in a progressive increase in its velocity (VA), its FVI, and its percent atrial contribution (%AC); (b) the three times diastolic filling time (DFT), mitral valve opening to Q wave (MVO-Q), and closure (Q-MVC) progressively shorten; (c) since DFT decreases, less passive filling occurs early during diastole, thus E.FVI decrease with longer AV intervals; (d) the ratios VE/VA and FVI E/A decrease subsequently to the previous described changes. Compared to CHB, percent ejection fraction (% EF) was not significantly changed during VVI pacing. Percent EF increased significantly during VDD in comparison to VVI pacing modes. Percent EF was highest at optimal AVD and decreased as this AVD increased or decreased. The cardiac output (CO) increment during VDD in comparison to VVI pacing modes differed much among the three groups. In group A, a 10.29% increase in CO was seen when comparing VDD pacing (with optimal AVD) with that of VII one; in group B, this increment was much greater and reached 29.48%; in group C it reached 23.68%.(ABSTRACT TRUNCATED AT 400 WORDS)

Mechanisms, diagnosis, and treatment of diastolic heart failure

Diastolic heart failure, in the absence of LV systolic dysfunction, is a common clinical condition that can be demonstrated in as many as one third of patients with congestive heart failure. Diastolic dysfunction caused by abnormalities in LV filling can be a result of many pathologic conditions, including hypertrophy, infiltrative cardiomyopathies, or myocardial ischemia. The major physiologic determinants of LV filling can be divided into cellular mechanisms, hemodynamic characteristics, and hormonal influences. Cellular mechanisms for impaired LV inactivation are determined by the handling of calcium within the myocyte during excitation-contraction-relaxation coupling. The hemodynamic characteristics of LV diastolic filling are determined by loading conditions, the time constant of isovolumic relaxation, heart rate, ventricular nonuniformity, pericardial restraint, myocardial elasticity, chamber compliance, and coronary blood flow. The sympathetic nervous system and the renin-angiotensin system are important modulators of diastolic filling, directly or indirectly. The diagnosis of heart failure is confirmed by a combination of clinical tests including invasive and noninvasive techniques, each of which has advantages and disadvantages. Treatment of medical conditions in which diastolic heart failure is a prominent component include pharmacotherapy with calcium channel antagonists, beta-adrenergic blocking agents, diuretic agents, and angiotensin-converting-enzyme inhibitors. Certain conditions associated with diastolic filling abnormalities such as pericardial disease or severe ischemic heart disease may be best managed by surgical or percutaneous intervention. Future research will include further delineation of the cellular mechanisms of active myocardial relaxation and clinical investigation into treatment directed at improving outcome.

Role of ischemia in postinfarction heart failure: hypothetical considerations based on use of verapamil in the DAVIT II Study. Danish Study Group on Verapamil in Myocardial Infarction

Based on a retrospective analysis of the DAVIT II database, we attempted to propose subgroups of post-infarction patients with heart failure, who might benefit or not benefit from antiischemic medical intervention. In DAVIT II, patients were randomized in a double-blind fashion to either verapamil 360 mg/day or placebo in the second week after the infarct and followed up to 18 months. The endpoint was the first major event; that is, death or reinfarction. In patients with heart failure but no ischemia, the event rate was 17.6% in the verapamil-treated patients and 16.5% in the placebo group (hazard verapamil: 1.01; 95% CL: 0.57, 1.79). In patients with both heart failure and residual ischemia, the event rate was 11.3% and 17.8% in the verapamil and placebo groups, respectively (hazard verapamil: 0.60; 95% CL: 0.24, 1.52). Although the latter reduction in major events was not statistically significant, we propose, in accordance with other studies, that in postinfarction patients with both heart failure and residual myocardial ischemia, the harmful negative inotropic effects of antiischemic drugs might be outweighed by their antiischemic effects, by means of which the prognosis might be improved. Patients without ischemia but with heart failure may, however, be at a disadvantage from such treatment.

The role of scintigraphic techniques in the evaluation of functional results of coronary bypass grafting and percutaneous transluminal coronary angioplasty

Scintigraphic techniques can be used first, to guide appropriate referral for interventional procedures, and second to predict the effect of revascularization on regional perfusion and function prior to the intervention, thereby being able to assess efficacy of revascularization and to assess whether ischemia is the origin of recurrence of symptoms. Of increasing importance is the ability of nuclear techniques to identify those myocardial regions with abnormal function which might benefit from revascularization by showing improvement in regional wall motion. Positron emission tomography is considered to be the gold standard to assess regional myocardial perfusion and metabolism. The introduction of the reinjection technique makes 201Tl-scintigraphy the method of choice to detect jeopardized myocardium and to guide appropriate referral for revascularization procedures in those institutes where PET is not available. Even when the costly PET-instrumentation is available, cost-benefit analysis is indicated to assess the additional value of PET compared with 201Tl reinjection imaging.

Left ventricular diastolic dysfunction in coronary artery disease: effects of coronary revascularization

Left ventricular diastolic dysfunction was studied globally and regionally in patients with coronary artery disease, and the effects of coronary revascularization were evaluated. A total of 25 patients with angina pectoris who had a stenotic lesion (greater than or equal to 90%) in only left anterior descending branch underwent coronary revascularization [percutaneous transluminal coronary angioplasty (PTCA) in 13 patients and coronary artery bypass graft (CABG) in 12]. Nine patients with normal coronary artery were studied as controls. Left ventricular volume and radial axes were measured on serial frames of one cardiac cycle by cine left ventriculography. The radial axes were drawn from the left ventricular gravity to left ventricular wall at every 20 degrees. Left ventricular filling fraction and distension rate of radial axes were calculated at the times of 25%, 50%, 75%, and 100% of diastolic period, 100% being end-diastole. Although there were no significant changes of the systolic function by revascularization, the filling fraction increased from 11.2 +/- 2.6 to 14.5 +/- 3.5% (p less than 0.001) at 25% time of diastole, from 29.9 +/- 4.9 to 32.5 +/- 5.0% (p less than 0.05) at 50% time in the PTCA group, and from 11.8 +/- 3.7 to 13.4 +/- 3.8% (p less than 0.01) at 25% time in the CABG group. The distension rate of radial axis to the anterior wall also increased significantly at 25% and 50% time of diastole after revascularization, and the change was marked in the PTCA group. However, these increases did not apply to the control patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term variation in myocardial ischemia during daily life in patients with stable coronary artery disease: its relation to changes in the ischemic threshold

Long-term variation in the frequency of myocardial ischemia during daily activity in patients with coronary artery disease who do not experience symptomatic changes has not been documented. Because at one point in time, the magnitude of such ischemia is strongly related to the ischemic threshold measured during exercise testing, this study was undertaken to determine whether patients with stable coronary artery disease show long-term variations in the frequency and duration of myocardial ischemia and to establish whether such variability is related to parallel changes in the ischemic threshold during exercise testing. Forty consecutive patients (mean age 61 +/- 8 years) who showed a stable clinical course over greater than or equal to 12 months were studied with a repeat exercise treadmill test and ambulatory electrocardiographic (ECG) monitoring after withdrawal of antianginal medications. The ischemic threshold was determined as the exercise time at 1 mm of ST segment depression. The mean interval to both follow-up evaluations was 15 +/- 3 months. Among the 23 patients with myocardial ischemia on ambulatory ECG monitoring at initial evaluation, the number and duration of ischemic episodes at follow-up were increased in 5 patients (mean increase 3.6 +/- 2 episodes and 123 +/- 98 min), unchanged in 1 patient and decreased in 17 patients (mean decrease 2.6 +/- 2 episodes and 98 +/- 72 min). Of the 17 patients without ischemic episodes at initial evaluation, 3 had evidence of ischemia on follow-up ambulatory ECG monitoring.(ABSTRACT TRUNCATED AT 250 WORDS)

Impairment of left ventricular function during coronary angioplastic occlusion evaluated with a nonimaging scintillation probe

Impairment of left ventricular function during controlled myocardial ischemia induced by coronary angioplasty has been reported from angiographic and echocardiographic studies. Ejection fraction, peak ejection, peak filling rates, and end-systolic and end-diastolic volumes were investigated before, during and after coronary occlusion on-line with a nonimaging scintillation probe. The study consisted of 18 patients (mean age 59 +/- 10 years) with coronary artery stenosis of greater than 70%. During balloon inflation of 60 seconds' duration, coronary occlusion pressure was 31.6 +/- 12 mm Hg. There was no significant change in heart rate. Delay between first and second dilatation was 109 +/- 63 seconds. Ejection fraction decreased from 53 +/- 16 to 40 +/- 12% (first dilatation, p less than 0.01) and to 39 +/- 14% (second dilatation, p less than 0.01) and recovered to 51 +/- 16% 5 minutes after the second dilatation. Peak ejection rate was significantly reduced during the first and second balloon inflations. Peak filling rate decreased from 2.5 +/- 0.8 to 2.0 +/- 0.7 end-diastolic volume.s-1 (first dilatation, p less than 0.01) and to 1.8 +/- 0.7 end-diastolic volume.s-1 (second dilatation, p less than 0.01) and remained reduced at 2.2 +/- 0.7 end-diastolic volume.s-1 (p = not significant) at 5 minutes after the second dilatation. End-systolic and end-diastolic volumes increased significantly during the first and second dilatations and returned to normal after dilatation. It is concluded that short, controlled myocardial ischemia during coronary angioplasty leads to a decrease in systolic and diastolic left ventricular function. Sequential dilatations do not further decrease function if a sufficient interval is kept.

Left ventricular diastolic filling in patients with coronary artery disease without myocardial infarction

Left ventricular diastolic dysfunction at rest was studied in 24 patients with coronary artery disease but no evidence of previous myocardial infarction. Seven patients with normal coronary arteries were studied as control. Diastolic filling was analyzed by the serial left ventricular volume and 14 radial axes from the gravity point of the left ventricle with cine left ventriculography. There were no differences in the systolic function between coronary artery disease and the normal control. Peak filling rate was decreased significantly in the groups with left anterior descending artery disease (LAD, p less than 0.05) and multivessel disease (MVD, p less than 0.05), but not in the group with right coronary artery disease (RCA). Time to peak filling rate was prolonged in each group of LAD (p less than 0.05), RCA (p less than 0.05), and MVD (p less than 0.001), compared with controls. The time-volume curve showed disturbed rapid filling in the LAD and RCA groups, and also both depressed rapid and slow filling in the MVD group. In the LAD group, the filling fraction was decreased significantly at the time of 25% of the diastolic period (p less than 0.001) and radial distension to the anterior wall was decreased at the time of 25%, 50%, and 75% of the diastolic period, compared with controls. In the RCA group, the filling fraction (p less than 0.001) and radial distension to the posterior wall were decreased only at the time of 25% of the diastolic period. In the MVD group, filling fraction and radial distension to the most wall were decreased at 25%, 50%, and 75% of the diastolic period.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of exercise radionuclide angiography with thallium SPECT imaging for detection of significant narrowing of the left circumflex coronary artery

Although quantitation of exercise thallium tomograms has enhanced the noninvasive diagnosis and localization of coronary artery disease, the detection of stenosis of the left circumflex coronary artery remains suboptimal. Because posterolateral regional wall motion during exercise is well assessed by radionuclide angiography, this study determined whether regional dysfunction of the posterolateral wall during exercise radionuclide angiography is more sensitive in identifying left circumflex disease than thallium perfusion abnormalities assessed by single-photon emission computed tomography (SPECT). One hundred ten consecutive patients with CAD were studied, of whom 70 had a significant stenosis of the left circumflex coronary artery or a major obtuse marginal branch. Both regional function and segmental thallium activity of the posterolateral wall were assessed using visual and quantitative analysis. Left ventricular regional function was assessed objectively by dividing the left ventricular region of interest into 20 sectors; the 8 sectors corresponding to the posterolateral free wall were used to assess function in the left circumflex artery distribution. Similarly, using circumferential profile analysis of short-axis thallium tomograms, left ventricular myocardial activity was subdivided into 64 sectors; the 16 sectors corresponding to the posterolateral region were used to assess thallium perfusion abnormalities in the left circumflex artery territory. Qualitative posterolateral wall motion analysis detected 76% of patients with left circumflex coronary artery stenosis, with a specificity of 83%, compared with only 44% by qualitative thallium tomography (p less than 0.001) and a specificity of 92%. Whereas quantitation of thallium activity increased the sensitivity for detecting left circumflex coronary artery stenosis to 80% with a specificity of 55%, it did not achieve statistical significance when compared with qualitative wall motion analysis.(ABSTRACT TRUNCATED AT 250 WORDS)

Correlation of quantitative angiographic parameters with changes in left ventricular diastolic function after angioplasty of the left anterior descending coronary artery

This study evaluates the changes in left ventricular (LV) diastolic filling after percutaneous transluminal coronary angioplasty and the relation of such changes to quantitative angiographic measurements of the severity of coronary narrowings. Pulsed Doppler echocardiographic measurements were performed in 40 patients with single left anterior descending artery narrowing before, and 10 and 30 days after angioplasty. Minimal luminal diameter and percent diameter stenosis of coronary lesions were measured by computer-assisted quantitation. The ratio of early to late diastolic flow velocities (E/A ratio), time velocity integral of early diastolic filling period (Ei) and the ratio of early and late diastolic filling periods (Ei/Ai ratio) increased gradually after angioplasty. Minimal luminal diameter correlated significantly with the percent changes in E/A ratio (r = 0.59 at 10 days, r = 0.57 at 30 days), Ei (r = 0.53 at 10 days, r = 0.55 at 30 days) and Ei/Ai ratio (r = 0.41 at 10 days, r = 0.49 at 30 days). Percent diameter stenosis showed overall weaker correlations than minimal diameter with the percent changes in E/A ratio (r = 0.39 at 10 days, r = 0.32 at 30 days) and Ei (r = 0.38 at 10 days, r = 0.31 at 30 days). Thus, LV diastolic filling improves serially after coronary angioplasty in patients with 1-vessel disease. The magnitude of improvement in diastolic filling correlates better with minimal luminal diameter than percent diameter stenosis. Therefore, minimal luminal diameter is a better predictor of changes in Doppler transmitral flow parameters after angioplasty than percent diameter stenosis.

Clinical efficacy of PTCA and identification of restenosis: evaluation by serial body surface potential mapping

We used serial body surface potential mapping (BSPM) with the departure map technique to evaluate the clinical efficacy of percutaneous transluminal coronary angioplasty (PTCA) in various pathophysiologic stages of coronary artery disease, and to detect restenosis. The BSPM was performed prior to, 1 week after, and 1 month after PTCA. A follow-up coronary angiography was performed 3 to 6 months after PTCA, and BSPM was also performed at the same time. The results of BSPM were compared with those of thallium-201 single-photon emission computed tomography (Tl-201 SPECT) and radionuclide ventriculography. After PTCA, BSPM showed a significant reduction in the departure area, the Tl-201 SPECT also showed a significant reduction in the extent and severity scores, and the left ventricular ejection fraction improved significantly. In the cases with restenosis, the departure area, which had decreased in size after PTCA, showed an increase in size. After successful re-PTCA, the size of the departure area again became smaller. We concluded that BSPM, which is a simple, noninvasive, and inexpensive method, is useful in the evaluation of the clinical efficacy of PTCA and in the detection of restenosis after successful PTCA.

Radionuclide methods to evaluate percutaneous transluminal coronary angioplasty

Radionuclide angiocardiography and myocardial perfusion imaging with exercise are valuable methods to assess patients undergoing percutaneous transluminal coronary angioplasty. Successful angioplasty results in improvement in ventricular systolic and diastolic function and regional perfusion. Complications of angioplasty, such as periprocedural infarction and side branch occlusion, can be documented noninvasively. Radionuclide methods have also been demonstrated to be of prognostic value in predicting coronary artery restenosis and recurrent cardiac symptoms. However, to avoid underestimating the success of coronary revascularization, studies must be scheduled long enough following angioplasty to allow transient abnormalities associated with artery dilation to resolve.

Effects of acute administration of gallopamil on left ventricular relaxation and filling dynamics in acute myocardial infarction assessed by Doppler echocardiography

The purpose of this study was to assess the acute effect of an intravenous bolus of the calcium antagonist gallopamil on left ventricular diastolic function using Doppler echocardiography. Fifteen patients with acute myocardial infarction in the first Killip class and sinus rhythm were randomized to an intravenous bolus of gallopamil (50 micrograms/kg over 5 minutes) or placebo in a crossover sequence. Doppler echocardiography was performed at baseline and 15 minutes after each bolus. No patients had received calcium antagonists or beta blockers before the study; all patients received nitroglycerin, which was withdrawn at least 2 hours before the baseline Doppler echocardiogram. The following Doppler parameters were calculated: the early (E) and late (A) peak filling velocities, the velocities ratio (E/A), the diastolic filling time-velocity integral (TVI), the peak filling rate normalized to the mitral stroke volume (nMPFR), the isovolumic relaxation time (IVRT), and the systolic flow velocity integral (SFVI). Expressing the parameters measured after a gallopamil bolus as the percent change of those measured after placebo, E, E/A, and nMPFR increased by 25.5 +/- 11.5%, 30.6 +/- 15.5%, and 19.0 +/- 12.2%, respectively (p less than 0.001); IVRT decreased by 13.5 +/- 7.0% (p less than 0.001); and TVI increased mildly by 6.9 +/- 9.9% (p = 0.01). SFVI and A did not change significantly. Negligible differences were observed between placebo and baseline values. Heart rate, mean blood pressure, and left ventricular and atrial diameters did not change significantly. It was concluded that gallopamil infusion improves early left ventricular filling and relaxation in patients with acute myocardial infarction. Considering the unchanged loading conditions, this indicates an improvement in left ventricular diastolic performance.

Transient left ventricular filling abnormalities (diastolic stunning) after acute myocardial infarction

A variety of experimental studies suggest that diastolic left ventricular (LV) function changes after acute myocardial infarction (AMI), but limited data exist on these changes in humans. To assess diastolic filling after AMI, 60 patients underwent Doppler echocardiographic examination within 24 hours of AMI. Of 54 patients who also underwent catheterization, 45 (83%) were successfully reperfused. A subgroup of 17 patients underwent a follow-up Doppler examination at 7 days after infarction, whereas 15 patients with stable exertional angina served as control subjects. There was no significant difference in age, gender, incidence of systemic hypertension or diabetes mellitus, heart rate, mean arterial pressure or severity of coronary artery disease between the infarct and control groups. The infarct group had a lower velocity time integral total (9.9 +/- 0.4 cm vs 12.0 +/- 0.9 cm, p less than 0.001), a lower velocity time integral E (5.8 +/- 0.3 cm vs 6.8 +/- 0.5 cm, p less than 0.01) and a lower velocity time integral 0.333 (3.5 +/- 0.4 cm vs 6.1 +/- 0.5 cm, p less than 0.01) than the control group. In addition, velocity time integral A/total was significantly greater in the infarction group (0.44 +/- 0.03 vs 0.35 +/- 0.04, p less than 0.01) compared to the control group. The follow-up subgroup showed an increase in velocity time integral total (p less than 0.01), velocity time integral E (p less than 0.05) and velocity time integral 0.333/total (p less than 0.05) over the first 7 days after infarction. The final recovery values at 7 days were not significantly different from those of the coronary artery disease group.(ABSTRACT TRUNCATED AT 250 WORDS)