Apex two dimensional echocardiography. Alternative approach to quantification of acute myocardial infarction

Quantification of left ventricular regional myocardial function using two-dimensional speckle tracking echocardiography in healthy volunteers--a multi-center study

BACKGROUND

Although two-dimensional speckle tracking (2DST) has been validated in animal and early clinical studies for quantitative evaluation of myocardial motion and contractility, there are only limited measurements in large healthy population to be used as reference data, which severely restricts its clinical application. This study aimed at determining the age-specific normal values of left ventricular (LV) longitudinal, circumferential and radial strain in healthy adults.

METHODS

We studied 228 healthy subjects (109 males, mean age 44 ± 15 years, range 18-78 years). Their LV longitudinal, circumferential and radial strains were measured by 2DST at basal, middle and apical levels of parasternal short-axis and apical 2-, 4- and 3-chamber views. The effects of age, gender and echocardiographic machines (52 patients had measurements obtained by both GE and Philips machines) on these parameters were also evaluated.

RESULTS

The longitudinal and circumferential strains were -20.4 ± 3.4% and -22.9 ± 3.1%, respectively with higher values being observed at basal than apical segments. On the contrary, the radial strain which ranged 42.6 ± 12.9% decreased towards apical segments. The longitudinal strain declined, the circumferential strain rose and the radial strain remained similar during aging. Adult females had slightly higher circumferential and longitudinal strains than males (23 ± 3% vs -22 ± 3%, -21 ± 3% vs -20 ± 3% respectively; both p<0.01). Strains measured by the 2 different echo machines had good correlations but Phillips-assessed strains (longitudinal and circumferential) were 10% higher than GE measurements. Inter- and intra-observer variabilities were acceptable.

CONCLUSIONS

Strain measurements by 2DST echocardiography varies with age, gender and echocardiographic vendors in healthy adults. These findings are important to differentiate between health and disease and to assess the severity of disease.

Strain and strain rate deformation parameters: from tissue Doppler to 2D speckle tracking

Strain and strain rate deformation parameters based on Color Doppler Myocardial Imaging, and more recently on two-dimensional (2D) gray scale images, have evolved as important methods for the quantification of myocardial function. Although these parameters are already applicable in the research field, their acquisition and analysis involve a number of technical challenges and complexities. Accurate knowledge of the basic principles of those techniques, as presented in this article, will further enhance their applicability to clinical practice.

Comparison of strain doppler echocardiography and radiologic left ventriculography for quantitative assessment of regional myocardial function

OBJECTIVE

We aimed to study the comparison of strain and strain rate parameters with conventional left ventriculography derived regional function.

METHOD

Forty patients were included in the study. The study group was selected from patients who had undergone left ventriculography and coronary angiography for clinical indications. Regional myocardial function was assessed using the centerline method via ACOM PC Quantcor LVA measurement system. Patients were also evaluated with echocardiography. Strain and strain rate Doppler echocardiographic measurements were compared with conventional left ventriculography at anterobasal, anterolateral, inferior and posterobasal segments.

RESULTS

Radiological left ventricular radial shortening was found to correlate with longitudinal strain shortening in all ventriculographic segments examined (anterobasal, r = 0.771, P < 0.0001; anterolateral, r = 0.790, P < 0.0001; posterobasal, r = 0.861, P < 0.0001; inferior, r = 0.815, P < 0.0001). Correlation was persistent both in patients with or without coronary artery disease. The sensitivity of a peak systolic longitudinal strain >12.5% for prediction of patients with radial shortening >or=20% was 75%, with a specificity of 100%. However, no relationship could be demonstrated between radiological left ventricular radial shortening and strain rate measurements.

CONCLUSIONS

In our study it was shown that regional wall motion can be measured quantitatively via strain Doppler echocardiography with the left ventriculography as reference.

Alterations of regional myocardial function in a swine model of myocardial infarction assessed by echocardiographic 2-dimensional strain imaging

BACKGROUND

Tissue Doppler strain and strain rate imaging have been introduced for quantitative assessment of regional myocardial function. These techniques are largely limited to the evaluation of overall longitudinal myocardial function. This study attempted to apply radial strain, circumferential strain, radial displacement, and strain-based torsion analysis to differentiating the infarct, adjacent, and remote zones in a swine model of myocardial infarction.

METHODS

Seven pigs, body weight 24 to 26 kg, were subjected to myocardial infarction by occlusion of the left anterior descending coronary artery (LAD) and followed up for 8 weeks. Regional radial and circumferential deformations were quantified noninvasively by ultrasonic strain rate imaging before LAD occlusion, LAD occlusion immediately, and 4, 6, and 8 weeks after LAD occlusion. Strain-based left ventricular torsion was assessed at the same time points.

RESULTS

Both radial and circumferential strains, and torsion, were decreased significantly in the LAD territory areas as a result of myocardial ischemia and infarction. There were no significant changes in radial and circumferential strains, or torsion, in the areas of adjacent and remote zones over time.

CONCLUSIONS

These findings demonstrate that speckle-tracking strain imaging may be suitable for noninvasive quantification of left ventricular segmental function of ischemic heart disease.

Detection of ischemia and new insight into left ventricular physiology by strain Doppler and tissue velocity imaging: Assessment during coronary bypass operation of the beating heart

BACKGROUND AND OBJECTIVES

Detection of myocardial ischemia in humans by strain Doppler and tissue velocity imaging was validated in a novel, experimentally designed study model during coronary bypass operation of the beating heart.

METHODS

Assessment of ischemia was made with an opened chest and pericardium inherent in the operative procedure. Longitudinal strain and tissue velocity of interventricular septal regions were measured by transesophageal echocardiography during occlusion of the left anterior descending coronary artery (LAD).

RESULTS

Unexpectedly, baseline velocities demonstrated that the apical and basal septum moved toward each other during systole. This occurred when the apex was dislodged from the pericardial sac to obtain access to the LAD, without any change in strain. The preceding motion of all septal regions toward the apex was reestablished after the heart was repositioned within the pericardium. In 16 patients with antegrade LAD flow, strain Doppler detected ischemia during LAD occlusion by disclosing systolic lengthening of the apical septum ( P <.01) and reduced shortening of the mid septum ( P <.05). The location and degree of ischemic changes coincided with the concomitant deterioration of wall motion. Tissue velocity changed in the basal and mid septum ( P <.05) but not in the apical region, explained by tethering effects and the distinctive motion pattern at baseline. There was no evidence of ischemia by invasive hemodynamic measures. In 7 patients with retrograde LAD flow, there were no significant changes in strain or tissue velocity measurements during LAD occlusion.

CONCLUSIONS

Strain by Doppler is a sensitive means for detecting myocardial ischemia, also capable of correctly localizing the ischemia, as opposed to tissue velocity assessment. However, velocity measurements provided new physiological information by disclosing the normal longitudinal motion of the heart to be dependent on the pericardial sac enveloping the apex, irrespective of the structural integrity of the pericardium.

Noninvasive quantification of regional myocardial function using Doppler-derived velocity, displacement, strain rate, and strain in healthy volunteers: effects of aging

Quantification of regional function can be performed using Doppler tissue echocardiography to evaluate myocardial velocity, tissue displacement, strain, and strain rate. Although these techniques have been validated in animal experiments and early clinical trials, there are only limited measurements in healthy populations to use as reference data. In 100 healthy volunteers, left ventricular myocardial velocity, displacement, strain, and strain rate were measured using Doppler tissue echocardiography. Measurements were obtained from basal, mid, and apical segments of walls visualized from left ventricular apical 4- and 2-chamber views. Analysis of covariance was used to examine the effects of age and wall segment position. All parameters showed a strong dependence on wall segment position. Although myocardial velocities and strain rate showed significant dependence on age, displacement and peak systolic strain measures were less affected. Like pulsed Doppler mitral inflow velocity, tissue velocity and strain rate show age-related changes.

Nicardipine or nitroglycerin in patients with failed percutaneous coronary angioplasty: effect on myocardial diastolic function

OBJECTIVE

To evaluate whether intracoronary vasodilators can improve diastolic function in 32 patients with failed percutaneous transluminal coronary angioplasty (PTCA).

DESIGN

Clinical trial.

SETTING

Single-institution, academic hospital.

PARTICIPANTS

Failed PTCA patients undergoing emergency coronary artery bypass grafting surgery.

INTERVENTIONS

Patients were divided into 2 groups: group A received 0.1 mg of intracoronary nicardipine, and group B received 20 microg of intracoronary nitroglycerin. Both drugs were administrated via a coronary dilatation perfusion catheter inserted in the catheterization laboratory by the cardiologist. Subsequently, they were continuously infused via the side port of the introducer of the pulmonary artery catheter and titrated to keep systolic blood pressure at about two thirds of the control value. Transesophageal echocardiography (Power Vision/6000, 9-mm 5MHZ Probe; Toshiba, Elmsford, NY) was used in this study.

MEASUREMENTS AND MAIN RESULTS

Left ventricular ejection fraction, cardiac index, tissue Doppler imaging velocity of the left ventricle and mitral annulus, and troponin levels were measured before and after administration of the 2 vasodilators and after cardiopulmonary bypass. Diastolic dysfunction was found preoperatively in all the patients and responded only to intracoronary nicardipine. Ea of mitral annulus velocity significantly increased in group A patients from 7.5 +/- 0.02 to 11.8 +/- 0.01 (p < 0.005) and decreased in group B patients from 8.0 +/- 0.03 to 7.5 +/- 0.02 after nicardipine or nitroglycerin administration. Left ventricular ejection fraction and cardiac index increased significantly (p < 0.005) only after nicardipine administration. Troponin levels were significantly lower in group A than in group B patients (p < 0.005).

CONCLUSION

Intracoronary nicardipine improves diastolic function and myocardial flow velocity in patients with failed PTCA undergoing emergency coronary artery bypass graft surgery.

Myocardial strain by Doppler echocardiography. Validation of a new method to quantify regional myocardial function

BACKGROUND

Myocardial strain is a measure of regional deformation, and by definition, negative strain means shortening and positive strain, elongation. This study investigates whether myocardial strain can be measured by Doppler echocardiography as the time integral of regional velocity gradients, using sonomicrometry as reference method.

METHODS AND RESULTS

In 13 anesthetized dogs, myocardial longitudinal strain was measured on apical images as the time integral of regional Doppler velocity gradients. Ultrasonic segment-length crystals were placed near the left ventricular (LV) apex and near the base. Apical ischemia was induced by occluding the left anterior descending coronary artery (LAD), and preload was increased by saline. Percentage systolic strain by Doppler correlated well with strain by sonomicrometry (y=0.82x-1.79, r=0.92, P<0.01). During LAD occlusion, apical myocardium became dyskinetic, as indicated by positive strain values and negative Doppler velocities. At the LV base, myocardial strain by Doppler, strain by sonomicrometry, and velocity of shortening by sonomicrometry (dL/dt) were unchanged during apical ischemia. However, myocardial Doppler velocities at the base decreased from 4.2+/-0.7 (+/-SEM) to 2.7+/-0. 4 cm/s (P<0.05), probably reflecting loss of motion caused by tethering to apical segments. Volume loading increased myocardial Doppler velocities from 2.2+/-0.3 to 4.1+/-0.8 cm/s (P<0.05) and Doppler-derived strain from -12+/-1% to -22+/-2% (P<0.05), whereas peak LV elastance remained unchanged.

CONCLUSIONS

Myocardial strain by Doppler echocardiography may represent a new, powerful method for quantifying regional myocardial function and is less influenced by tethering effects than Doppler tissue imaging. Like myocardial Doppler velocities, strain is markedly load-dependent.

New method for evaluating left ventricular wall motion by color-coded tissue Doppler imaging: in vitro and in vivo studies

OBJECTIVES

The aim of this study was to examine the accuracy and validity of a newly developed tissue Doppler imaging system in in vitro and in vivo studies.

BACKGROUND

Because quantitative measurement of wall motion velocity in real time is still difficult by conventional echocardiography, we developed a new system for evaluating ventricular wall motion by analyzing Doppler signals from cardiac tissue.

METHODS

We used a modified Doppler color imaging system, omitting the high pass filter to allow Doppler signals from cardiac tissue to enter the auto-correlator. Ultrasound carrier and pulse repetition frequencies were 3.75 MHz and 3.0 to 6.0 kHz, respectively. Under these conditions, the lowest measurable velocity was 0.2 cm/s.

RESULTS

In the rotating sponge model, the measured velocity correlated well with the actual velocity (y = 0.97x + 2.17, r = 0.99). In clinical settings, the mid-ejection mean velocity at either endocardial or epicardial sites of the left ventricular posterior wall measured by M-mode tissue Doppler imaging correlated well with that measured by conventional M-mode echocardiography (y = 0.94x + 0.64, r = 0.99). During systole, in healthy subjects, the anterior left ventricular wall was color-coded blue and the posterior wall was color-coded red, whereas the akinetic regions associated with myocardial infarction showed no color throughout the cardiac cycle. The ventricular posterior wall excursion velocity, defined as the difference between velocities at the endocardial and epicardial sites, was significantly slower in patients with dilated cardiomyopathy (0.4 +/- 0.3 cm/s) than in normal subjects (2.0 +/- 0.6 cm/s).

CONCLUSIONS

These results indicate that the present system accurately represents tissue velocity and can create two-dimensional color images that facilitate visual assessment of ventricular wall motion.

Diagnosis of recent myocardial infarction with quantitative backscatter imaging: preliminary studies

Acute myocardial ischemia and chronic myocardial infarction may be recognized with ultrasound tissue characterization techniques because of myocardial acoustic changes caused by reduced perfusion and/or collagen deposition. Our purpose was to study the acoustic properties of recent myocardial infarction when the predominating pathologic finding was myocardial edema and leukocytic infiltration. We used a new quantitative backscatter imaging system to study 18 patients 9 +/- 5 days after myocardial infarction (eight patients with anteroseptal myocardial infarction and 10 with inferior myocardial infarction) and 20 normal subjects. The cyclic variation of relative integrated backscatter (end-diastolic minus end-systolic) was calculated from on-line measurements. Standard parasternal long- and short-axis and apical four- and two-chamber views were obtained. In the anteroseptal myocardial infarction group, the cyclic variation of relative integrated backscatter was lower in the septum (1.5 +/- 1.6 dB) than in the posteroinferior wall (3.2 +/- 1.2 dB); however, the sample size of only three patients (of eight patients imaged) in the latter group prevented statistical comparison. The cyclic variation of relative integrated backscatter in the infarcted septum was less than the measurement obtained in the septum of the control group (4.3 +/- 2.4 dB, p less than 0.05). In the inferior infarction group, the cyclic variation of integrated backscatter in the posteroinferior wall (1.8 +/- 1.7 dB) was not significantly different from the measurement obtained in the septum (3.7 +/- 3.6 dB); however, the cyclic variation in the posteroinferior wall was significantly less than that obtained in the control group posteroinferior wall (5.7 +/- 1.7 dB, p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Early Indium-111 antimyosin scintigraphy for assessment of regional wall motion asynergy on discharge after myocardial infarction

To assess the relation between early Indium-111 monoclonal antimyosin antibody scintigraphy and degree of regional asynergy on discharge, 38 patients with a first acute myocardial infarct were studied (18 anterior, 20 inferoposterior infarctions). In 21 patients thrombolytic therapy was administered. On the first day of myocardial infarction, 80 MBq Indium-111 Antimyosin was injected. Planar images, anterior, lateral and left anterior oblique, were made 24 hours later. Localized myocardial uptake was present in 37/38 patients, and was evaluated for Count Density Index (count density of infarct zone/left lung count density) in the left anterior oblique images, which displayed the infarct zone well. Regional asynergy on discharge was evaluated by cross-sectional echocardiography and defined mild (hypokinesia) or severe (akinesia or dyskinesia). Count density index was significantly lower in 15 patients with mild asynergy, compared with 22 patients with severe asynergy (1.61 +/- 0.25 vs. 2.42 +/- 0.40, p less than 0.001). This difference was present in both patient groups treated with or without thrombolysis. We conclude that early count density index, reflecting the amount of local necrosis, is highly correlated to the ultimate degree of wall motion impairment.

Predictive value of indium-111 antimyosin uptake for improvement of left ventricular wall motion after thrombolysis in acute myocardial infarction

In 21 patients treated with thrombolysis for acute myocardial infarction (AMI), the degree of myocardial uptake of indium-111 monoclonal antimyosin antibodies injected within 24 hours after onset of AMI was compared with the degree and extent of regional asynergy on admission and discharge, as assessed by 2-dimensional echocardiography. On the first day of AMI, 80 MBq of indium-111 antimyosin was injected and planar images were made 24 hours later. Indium-111 antimyosin uptake was evaluated for count density index (count density of infarct zone/left lung count density) in the left anterior oblique projection, in which the infarction zone was well displayed in all patients. Using 2-dimensional echocardiography, the left ventricle was divided into 13 segments and evaluated for regional asynergy, which was considered severe (akinesia or dyskinesia) or mild (hypokinesia). The extent of regional asynergy was measured by the number of asynergic segments. All 21 patients had severe regional asynergy on admission. Nine of 21 showed only mild regional asynergy on discharge and 12 of 21 had persistent severe regional asynergy in at least 1 segment. The count density index was significantly lower in patients with mild regional asynergy on discharge compared with patients with severe regional asynergy (1.63 +/- 0.27 vs 2.50 +/- 0.42, p less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Predictive value of two-dimensional echocardiographic and hemodynamic measurements on admission with acute myocardial infarction

To identify high-risk patients with acute myocardial infarction, we compared admission values of two-dimensional echocardiography and hemodynamic monitoring. Left ventricular wall motion score (WMS), left ventricular stroke work index (LVSWI), and pulmonary capillary pressure (PCP) were obtained in 77 patients without clinical signs of heart failure. Progression into Killip grade 3 or 4 was found in 16 of 77 patients (21%) within 32 +/- 6 hours (mean +/- 1 standard deviation) after admission. Mean WMS, LVSWI, and PCP in those patients who developed severe pump failure were significantly different from those who did not: 13.4 +/- 4.9 versus 7.3 +/- 4, 30 +/- 4 versus 46 +/- 11 gm/m2, and 21 +/- 8 versus 12 +/- 6 mm Hg, respectively. Sensitivity of WMS of greater than 7 and LVSWI of less than 35 gm/m2 in predicting Killip grade 3 or 4 was 88% and 94%, specificity was 57% and 87%, positive predictive value was 35% and 65%, and negative predictive value was 95% and 98%. Sensitivity of PCP was low (50%). Early identification of patients developing myocardial rupture or reinfarction was limited by both methods. We conclude that echocardiographic examination on admission in patients with acute myocardial infarction provides an alternative approach for early identification of low-risk patients.

Short and long term predictive value of admission wall motion score in acute myocardial infarction. A cross sectional echocardiographic study of 345 patients

A score of left ventricular segmental wall motion was used as a convenient rapid way to assess overall left ventricular function in acute myocardial infarction. Its success in risk stratification at admission was assessed by a blind review of cross sectional echocardiographic tape recordings from multiple acoustic windows. Sixty nine (20%) of the 345 patients died during hospital stay or within a one year follow up. The mean (SD) wall motion score in those who died was significantly higher than in those who survived (16.2 (5.9) vs 5.7 (3.9)). There were no differences between the group that died in hospital within three months of discharge and the group that died between three months and one year after discharge. Among the 31 patients who died in hospital, however, wall motion score was highest in 15 patients dying of cardiogenic shock (19.2 (4.2)). In 16 patients with lethal ruptures it was 13.5 (6.1). The nine patients with free wall ruptures had higher wall motion scores than those with ventricular septal rupture or papillary muscle rupture (15.7 (6.9) vs 8.5 (5.3)). Eight (3.3%) of 245 patients with a score less than 10 died, compared with 61 (61%) of 100 scoring greater than or equal to 10. The sensitivity of a score of greater than or equal to 10 in predicting death within one year was 88%, the specificity was 86%, the positive predictive value was 61%, and the negative predictive value was 97%.

Two-dimensional echocardiographic detection of left ventricular posterior wall motion abnormalities using an inferior angulation view

Two-dimensional echocardiography is frequently used to detect left ventricular (LV) wall motion abnormalities. Modification of the apical 4-chamber view by inferior angulation of the transducer provides a superior image for detection of regional wall motion abnormalities of the LV posterior wall. The inferior angulation image was prospectively compared with the standard parasternal short-axis image for detection of posterior LV wall motion abnormalities as defined by contrast left ventriculography in 63 consecutive patients. Posterior wall akinesia was present on the contrast left ventriculogram in 22 of the 63 patients. The parasternal short-axis image was judged technically inadequate for interpretation in 7 patients (11%). The inferior angulation image was technically adequate for interpretation in all patients. The sensitivity, specificity and accuracy of the inferior angulation image for detection of LV posterior wall motion abnormality was 91%, 80% and 84%, respectively, vs 67%, 71% and 70% for the parasternal short-axis image. The differences between the sensitivity, specificity and accuracy for the 2 views were not statistically significant. These observations indicate that the inferior angulation image provides a useful plane for routine echocardiographic analysis of regional LV wall motion either as a primary method to detect posterior wall motion abnormality or as a confirmatory view to document posterior wall motion abnormality.

Two-dimensional echocardiography during percutaneous transluminal coronary angioplasty

In order to study myocardial and clinical events during transient coronary occlusion in humans, two-dimensional echocardiography was continuously performed in 15 patients undergoing 49 balloon inflations during percutaneous transluminal coronary angioplasty (PTCA). Transient segmental asynergy developed in all patients 8 +/- 3 seconds after balloon inflation and returned to baseline 19 +/- 8 seconds after balloon deflation. Segmental dyskinesis was seen in only 8 of 11 patients undergoing PTCA of the left anterior descending artery (LAD). A wall motion score, based on degree of asynergy of 13 segments of the left ventricle, was significantly higher during LAD than during right coronary artery inflation (7.9 +/- 1.3 vs 4.0 +/- 1.4, p less than 0.01). Left ventricular size index increased significantly during balloon inflation, from 179 +/- 9 to 196 +/- 10 mm (p less than 0.01). Four patients developed transient ST segment changes in the extremity leads of the ECG and five patients had angina pectoris. The very first sign of ischemia in three patients, who developed all of these symptoms together, was consistently asynergy, followed by ECG changes, and last, angina pectoris. Thus during PTCA, transient asynergy and left ventricular dilatation develop, which are often clinically silent.

Incidence, timing and prognostic value of left ventricular aneurysm formation after myocardial infarction: a prospective, serial echocardiographic study of 158 patients

Serial 2-dimensional echocardiography was performed prospectively in 158 consecutive patients with first acute myocardial infarction (AMI) to determine the incidence of left ventricular (LV) aneurysm formation and the time course required for, and the clinical significance of, onset of LV aneurysm formation. Studies were performed throughout the first 5 days and after 3 months and 1 year. LV aneurysm was defined as an abnormal bulge in the LV contour during both systole and diastole. Eighty-four patients had anterior, 68 posterior and 6 anteroposterior AMI defined echocardiographically. During the study period, LV aneurysm was found in 35 of 158 patients (22%): in anterior AMI in 27, in posterior AMI in 6 and in anteroposterior AMI in 2. No new aneurysm developed after 3 months. Early aneurysm formation, during the first 5 days after AMI, was seen in 15 patients with anterior infarction. Twelve of these 15 (80%) died within 1 year (10 within 3 months), in contrast to 5 (25%) of the remaining 20 patients with LV aneurysm (p less than 0.05). Dyskinesia of the anterior wall in the acute stage usually resulted in aneurysm formation. Thus, LV aneurysm formation is seen in 22% of mostly anterior AMI and occurs within 3 months after AMI. Early aneurysm formation is associated with a high 3-month (67%) and 1-year (80%) mortality rate.

Asynchronous left ventricular wall motion early after coronary thrombosis

To study regional wall motion early in the development of acute myocardial infarction, left ventriculograms performed in 24 patients before thrombolysis and within 3.5(1.2) (mean (SD] hours of the onset of pain were digitised frame by frame. Isometric and contour plots of regional wall motion were constructed. In 19 patients (seven with anterior descending, eight with right, and four with circumflex disease) thrombosis was demonstrated on an underlying stenosis. In 10 patients the two remaining coronary arteries were normal, and in nine, one or both showed important disease. Mean values of global indices of left ventricular function, including end diastolic volume, ejection fraction, peak ejection and filling rates, and cavity shape changes were all within normal limits, though end systolic volume was significantly raised. Total systolic amplitude of wall motion was normal in the affected area in all but seven patients (four with anterior descending, two with right, and one with circumflex thrombosis). Dyskinesis of more than 2 mm was seen in only three patients, all with thrombosis of the anterior anterior descending coronary artery, and hyperkinesis was present in four. The commonest abnormality of wall motion was hypokinesis during ejection followed by prolonged inward motion during isovolumic relaxation, which was seen in four patients with anterior descending, seven with right, and three with circumflex artery thrombosis. This was preceded by outward motion during isovolumic contraction and delayed inward motion during ejection in eight with right or circumflex thrombosis. Five of six patients without thrombosis had simple hypokinesis or dyskinesis without asynchrony. Disease of other coronary arteries did not affect the pattern of wall motion seen after right or circumflex coronary artery occlusion but it reduced the incidence of delayed inward motion along the free wall after thrombosis of anterior descending artery. Thus early after acute coronary thrombosis asynchronous wall motion is commoner than simple hypokinesis or dyskinesis. Its persistence suggests that in the setting of coronary artery thrombosis in man, residual contractile activity may persist for up to six hours after the onset of symptoms.

Long-term follow-up of left ventricular thrombus after acute myocardial infarction. A two-dimensional echocardiographic study in 96 patients

To determine the incidence, natural history, and relation to anticoagulant therapy of left ventricular thrombus (LVT) following acute myocardial infarction (MI), we performed two-dimensional echocardiography in 96 consecutive patients with isolated MI during the acute episode and after four and 12 months. Only patients with anterior MI received oral anticoagulant therapy on admission and throughout the study period. The LVT was identified in 21/65 patients with anterior and in 1/31 patients with inferior MI. The large majority of LVT cases were seen for the first time during the acute phase of MI. LVT was associated with a significantly higher peak value of CK-MB (118 +/- 24 vs 76 +/- 35, p less than 0.001) and Killip class (2.5 +/- 0.8 vs. 1.5 +/- 0.7, p less than 0.002). Patients with anterior MI and LVT more frequently had segmental dyskinesia during acute MI than patients without LVT (86 percent vs 18 percent, p less than 0.001). In four patients LVT resolved during the study period. Discontinuation of anticoagulant therapy in four patients with an aneurysm led to LVT formation in three. Two patients suffered a clinically recognized embolic event; one never had LVT demonstrated by echocardiography. Thus, LVT usually develops in the early days following large anterior MI, complicated by pump failure and segmental dyskinesia, even when patients receive oral anticoagulant therapy. Surprisingly, the incidence of embolic events was low (1/22) in our LVT patients.

Anatomical basis of cross sectional echocardiography

Ten hearts were cut in planes to simulate echocardiographic cuts which may be taken to visualise the anatomy of the cardiac chambers and great arteries. The various myocardial wall segments were named from these sections by referring to their position in the reconstituted heart. The sections were studied in their correct anatomical position. In this way they provide a reference for appropriate orientation of echocardiographic images.