Embolic potential of left ventricular thrombus after myocardial infarction: a two-dimensional echocardiographic study of 119 patients

Left ventricular thrombus complicating myocardial infarction was diagnosed by two-dimensional echocardiography in 119 patients. The infarct site was anterior in 98 patients and inferior in 11. Systemic embolism occurred in 26 patients (stroke in 18, lower limb embolism in 7 and mesenteric embolism in 1). A protruding configuration of the thrombus was more common in the patients with embolism than in those without (23 [88%] of 26 versus 17 [18%] of 93) (p less than 0.01). Free mobility of the thrombus was found in 15 (58%) of 26 and 3 (3%) of 93 cases, respectively (p less than 0.01). In predicting embolism, protruding thrombus configuration had a sensitivity of 88% and a specificity of 82%, and positive and negative predictive accuracy was 57 and 96%, respectively. For free mobility of the thrombus, sensitivity was 58%, specificity 97%, positive predictive accuracy 85% and negative predictive accuracy 89%. In the 46 patients whose echocardiogram was obtained during the hospital admission for the index infarct, repeat echocardiograms were obtained during oral anticoagulant therapy. Twelve of these 46 patients had embolism and 2 of the 12 died. In seven of these patients, full dose oral anticoagulant therapy had been given before embolism occurred and in five it was started after an embolic event. The thrombus decreased in size or disappeared in six patients; in four the thrombus showed no change, and in two of these four emboli recurred despite anticoagulation. It is concluded that two-dimensional echocardiography may help delineate the embolic potential of left ventricular thrombus complicating myocardial infarction and may be of value in weighing the benefits and disadvantages of oral anticoagulant therapy.

Immediate and long-term effects of nicardipine, at rest and during exercise, in patients with coronary artery disease

Haemodynamic effects of nicardipine were studied in 12 patients with documented coronary artery disease. Following nicardipine 10 mg, given intravenously to patients at rest, the heart rate increased, mean arterial pressure decreased, cardiac index increased, and systemic vascular resistance decreased significantly. Compared with the control exercise values, significant increases in heart rate and cardiac index and significant decreases in mean arterial pressure, systemic vascular resistance, and left ventricular end diastolic pressure occurred when nicardipine, 10 mg i.v., was given to the patients during exercise. All 12 patients complained of angina during the exercise phase, but following treatment with nicardipine, 10 mg i.v., only four patients reported angina when exercising to the same level. Exercise capacity on oral nicardipine treatment tended to increase whilst the ejection fraction response to exercise did not change. Thus, nicardipine was a potent vasodilator, which produced a marked reduction of systemic vascular resistance and left ventricular end diastolic pressure during exercise.

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.

Two-dimensional echocardiographic appearance of left ventricular thrombi with systemic emboli after myocardial infarction

To test the hypothesis that left ventricular (LV) thrombi that project into the lumen and are mobile are more likely to embolize than those that do not have these characteristics, the 2-dimensional echocardiograms of 16 patients with LV thrombi after myocardial infarction were retrospectively reviewed. Ten had evidence of peripheral embolization and 6 did not. The studies were reviewed in random order by an observer blinded to the clinical data. Each echocardiogram was graded as showing a protruding or nonprotruding thrombus and the presence or absence of increased mobility. The thrombus projected into the lumen on the echocardiograms of 8 of 10 patients who had had emboli and in 0 of 6 who had not. The thrombus had increased mobility in 4 of 10 patients with emboli and 0 of 6 without. Thus, LV thrombi that project into the lumen and have increased mobility are more likely to embolize than those without these characteristics.

Serial left ventricular ejection fraction in acute myocardial infarction by cross-sectional echocardiography: correlation of changing ejection fraction with clinical course

Left ventricular volume and ejection fraction were measured in 22 survivors of acute myocardial infarction by means of two-dimensional echocardiography and using a Simpson's rule algorithm. Ten of the 22 patients experienced complications. For the group as a whole, there were no significant trends in left ventricular volume and ejection fraction between the first and third days and the third month after infarction. In the subgroups with uncomplicated and complicated infarction, there were trends towards increasing and decreasing ejection fractions, respectively, which failed to attain statistical significance, however. The difference in ejection fraction between both subgroups had become significant at 3 months; 55.2 +/- 11.1% in uncomplicated v. 41.3 +/- 6.9% in complicated cases (P less than 0.01). Individual changes in ejection fraction falling outside the limits of reproducibility of the method as assessed previously were observed between day 1 and day 3 in only 2 patients with uncomplicated and in 2 patients with complicated infarction. Between day 1 and 3 months such changes occurred in 8 patients with uncomplicated infarction (upward in 5 and downward in 3), and in 8 patients with complicated infarcts (upward in 3 and downward in 5). We conclude that changes in ejection fraction as measured by two-dimensional echocardiography tend to correlate with complications.

Measurement of left ventricular ejection fraction after acute myocardial infarction. A serial cross sectional echocardiographic study

Left ventricular ejection fraction was assessed by biplane cross sectional echocardiography in 65 patients with a first acute myocardial infarction on the first day. In 30 patients (group 1) measurements were repeated on the third day and in another 35 patients (group 2) at three months. Changes in ejection fraction of 0.05 or less were arbitrarily called insignificant. In group 1 only two patients showed a decrease of more than 0.1 between days 1 and 3, and both had an enzymatically confirmed infarct extension. The remaining patients had no complications. In group two 11 patients had decreases of more than 0.1 between day 1 and three months: three of them had an enzymatically confirmed reinfarction (perioperative in one) and four a possible reinfarction, and in two an angiographically confirmed left ventricular aneurysm developed. In two no complications occurred. The other complications that occurred were an enzymatically confirmed but small reinfarction, an angiographically confirmed but circumscript aneurysm, and an uncomplicated bypass operation in one patient each. These three patients had a small increase (between 0.05 and 0.1) in ejection fraction. Reproducibility of the method of measuring the ejection fraction was assessed concurrently in 20 outpatients with a previous myocardial infarction who were studied twice on the same day (with a 30 minute interval) by two different observers. The mean absolute difference in ejection fraction between the paired observations was 0.036 +/- 0.023 with a range of 0 to 0.07. Thus only changes in ejection fraction of more than 0.1 correlate with clinically recognised complications. Changes between 0.05 and 0.1 may be due to spontaneous variability or to the limited reproducibility of the method.

Early two-dimensional echocardiographic measurement of left ventricular ejection fraction in acute myocardial infarction

Left ventricular volume and ejection fraction were measured by 2-dimensional echocardiography from 2 orthogonal apical long axis views in 90 patients admitted with acute transmural myocardial infarction. Results were correlated with worst Killip class during hospital stay, enzymatic infarct size (peak CK-MB) and mortality. We used two algorithms, a biplane area-length algorithm and a modification of Simpson's rule. Both algorithms yielded essentially the same results: there were statistically significant trends towards higher end-diastolic and end-systolic volumes and lower ejection fraction with higher Killip -class. Ejection fraction was lower (P less than 0.01) in the 6 patients dying from cardiogenic shock (28.0 +/- 7.8% v. 46.6 +/- 10.1% in survivors with the area--length algorithm; 28.1 +/- 6.2% v. 48.1 +/- 10.2% with modified Simpson's rule). In 5 patients dying from other causes ejection fraction was 46.0 +/- 14.9% with the area-length method or 46.2 +/- 14.5% with Simpson's rule (not different from survivors). Correlation with peak CK-MB was only modest, though statistically significant: the regression equation was: y = -0. 39x + 54 (r = -0.35; P less than 0.01) with the area-length method; and y = -0. 41x + 55 (r = -0.37; P less than 0.01) with Simpson's rule. Left ventricular ejection fraction measured at the bedside in patients with acute myocardial infarction, can provide useful clinical information. Patients likely to develop shock can be identified shortly after admission.

Thallium-201 scanning to decide CCU admission in patients with non-diagnostic electrocardiograms

To determine the value of thallium-201 scintigraphy as a decisive factor in admission policy for patients with acute chest pain and nondiagnostic electrocardiograms, we undertook a prospective study in 149 such patients. The interval between pain and scan never exceeded 12 hr. Of 57 patients in whom a defect was seen, 34 had an acute infarction, 7 developed infarction within 2 months, and in 11 coronary heart disease was proven by angiography or strongly suggested by stress tests (ECG and thallium-201 scan). In 13 patients with an equivocal scan, coronary heart disease was proven or strongly suggested in 5. Of 79 patients with a normal scan, only 1 had acute infarction, and stress tests were positive in 6 and negative in 72. In these 72 no cardiac event occurred during a 1-year follow-up. Thallium-201 scintigraphy can help to select those patients with acute chest pain and nondiagnostic electrocardiograms who need observation in a CCU.

Comparison of two-dimensional echocardiography with radionuclide angiography during dynamic exercise for the detection of coronary artery disease

Two-dimensional echocardiography (2DE) was performed during 30-degree left lateral decubitus bicycle exercise in 52 patients who underwent cardiac catheterization for suspected coronary artery disease (CAD). Adequate echocardiograms were obtained in 39 patients (75%). Thirty-five of these patients underwent radionuclide angiography (RNA) with the same exercise protocol as for echocardiography. Exercise-induced or increased initial asynergy was considered to be a positive test by both 2DE and RNA. Echocardiographic, scintigraphic, and coronary angiographic data were compared to each other. Significant CAD (greater than 50% luminal obstruction) was present in 26 patients (66%). One of 15 patients with exercise-induced asynergy by 2DE had no CAD. Six 2DE and two RNA studies during exercise were falsely negative, sensitivity 76% versus 91%. Inclusion of RNA ejection fraction data would increase the sensitivity but decrease the specificity of RNA. Exercise-induced septal asynergy was far more frequently present by 2DE than by RNA (11 versus 6) in the 17 patients who had exercise-induced anterior asynergy by both methods. We conclude that it was possible to perform exercise 2DE in 75% of our patients. Exercise-induced asynergy on 2DE was specific (92%) for CAD. The sensitivity of 2DE in detecting CAD was less than that of RNA.

Left ventricular thrombus following acute myocardial infarction: a prospective serial echocardiographic study of 96 patients

In a prospective serial study of 96 patients with acute myocardial infarction, two dimensional echocardiography identified left ventricular thrombus in 18 patients. The majority of thrombi (15) developed within the first 4 days after admission. In three patients thrombi were identified for the first time 4 months after the acute episode. All 18 patients had received therapeutic anticoagulants on admission and had large anterior wall infarctions complicated by severe pump failure and motion abnormalities echocardiographically. None of the patients had systemic embolisation during the study period. Thus, left ventricular thrombus is a not uncommon though silent complication of acute anterior wall infarction even when patients receive therapeutic anticoagulants.

Two dimensional echocardiography in the diagnosis of left ventricular thrombus. A prospective study of 67 patients with anatomic validation

Seventy-two patients, in whom a high prevalence of left ventricular thrombus (LVT) was anticipated, were studied prospectively by two-dimensional echocardiography (2DE). Adequate echocardiograms were obtained in 67 patients (93 percent). Presence or absence of LVT was verified at surgery in 51 patients undergoing aneurysmectomy, and at autopsy in 16 patients dying from acute myocardial infarction. Twenty-six patients had LVT and 41 did not. The LVT was defined echocardiographically as an echo-dense mass adjacent to asynergic left ventricular wall and distinct from the endocardial surface. Twenty-four of 26 LVT were correctly predicted by 2DE (sensitivity 92 percent). Absence of LVT was correctly predicted in 36 of 41 patients (specificity 88 percent). In five patients, LVT by 2DE was not anatomically confirmed (17 percent false positives). Thus, 2DE can detect or exclude the presence of LVT with a good sensitivity and specificity.

Echocardiographic-cineangiographic correlation in detecting left ventricular aneurysm: a prospective study of 422 patients

Four hundred twenty-two consecutive patients with a documented myocardial infarction underwent cardiac catheterization and echocardiographic examination. Adequate two dimensional echocardiograms were obtained in 386 patients (91 percent). Left ventricular aneurysm was defined echocardiographically and cineangiographically as a well demarcated bulge in the contour of the left ventricular wall during both diastole and systole, demonstrating dyskinesia or akinesia. Cineangiography was considered as the standard for the diagnosis of left ventricular aneurysm. The site of aneurysm was mainly anteroapical. An aneurysm was judged present on cineangiography in 111 patients and on echocardiography in 118 patients. The presence and absence of an aneurysm echocardiographically correlated in 103 and 260 patients, respectively, with cineangiography. In 8 patients a cineangiographically identified aneurysm was not manifested echocardiographically, whereas in 15 patients an aneurysm identified on echocardiography was not evident on cineangiography. Thus two dimensional echocardiography can detect or exclude a left ventricular aneurysm with a high level of sensitivity (93 percent) and specificity (94 percent).

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

Apex echocardiography has been chosen as an approach to detect and quantify acute myocardial infarction because the usual parasternal acoustic windows are often occluded. Fifty-three patients were studied, all within 12 hours after the onset of symptoms of their first myocardial infarction. Three apical long axis views were obtained, that is the two and four chamber views, and the right anterior oblique equivalent or three chamber view. Satisfactory echocardiograms were obtained in 48 patients (91%). The individual apical views were divided into equal segments and the area of asynergy was estimated in each view. Left ventricular asynergy was present in all 48 patients. In 46 patients a positive correlation between the electrocardiogram and the echocardiogram was obtained, as far as infarct localisation was concerned. The estimated asynergic area correlated well with the peak value of the isoenzyme of creatine kinase (CK MB). Apex echocardiography is a reliable alternative method of detecting and quantifying myocardial infarction soon after the onset of symptoms.

Variation in fecal pollution indicators through tidal cycles in the Fraser River estuary

Daily fluctuations in fecal pollution indicators in the Fraser River estuary were examined by sampling through 24 h at four sites; water levels, currents, and salinities were observed simultaneously. Fecal coliforms were measured on shipboard using the membrane filter technique, and coprostanol and cholesterol were extracted using hexane and analyzed by gas chromatography. Maximum concentrations of fecal sterols and coliforms occurred after high tide at the station upstream of major sewage outfalls and on the ebb or at low tide at the stations downstream of major sewage outfalls. Fecal coliform counts were highly correlated with coprostanol and cholesterol levels at sites near sewage treatment plants. Coprostanol was highly correlated with cholesterol except where concentrations approached detection limits. In receiving waters, fecal coliform counts but not sterol concentrations were reduced by chlorination of sewage treatment plant effluents during the summer months. We concluded that, dependent on the objectives of a future monitoring program, samples should be collected either randomly in time such that the seasonal or annual mean includes tidal variability or systematically during the ebb tide to assess contributions to bathing beaches and shellfish harvesting areas. Fecal sterols deserve consideration as potentials indicators of fecal contamination from chlorinated sewage effluents.

Detection and quantification of acute, isolated myocardial infarction by two dimensional echocardiography

Ninety consecutive patients with acute, isolated myocardial infarction were evaluated with two dimensional echocardiography. Satisfactory echocardiograms were obtained in 66 patients (73 percent). All patients were studied 2 to 12 hours after the onset of symptoms. Sixty patients had additional studies at 48 and 72 hours. Long axis views were obtained at the base, body and apex of the left ventricle. Five short axis views of the left ventricle were obtained at different levels from the cardiac base to the apex. The individual short axis views, corrected for the end-diastolic internal diameter of the left ventricle, were divided into equal segments and the area of asynergy in each view was estimated. Infarct localization was similar on electrocardiography and echocardiography in 62 of 66 patients. In two dimensional echocardiography in one patient. The results of an echocardiographic study in one patient were false negative. During the study period the individual asynergic area remained stable. The initial asynergic area correlated well (r = 0.87, p less than 0.01) with the peak value of the isoenzyme of creatine kinase (CK-MB), which occurred hours later. Thus, two dimensional echocardiography is a reliable method to localize and quantify, early after the onset of symptoms, the eventual extent of myocardial involvement in patients with acute, isolated infarction.

Steroid-nucleosides

A new class of potential chemotherapeutic agents consisting of steroids coupled with nucleoside bases is described. Such structures may be viewed as nucleosides in which the sugar moiety is replaced by a steroid molecule. We may therefore expect the nucleoside characteristics to give interference at the DNA level, resulting in the desired antitumor activity, whereas the steroid moiety may provide target specificity. A number of such coupling products were prepared and preliminary biologic studies are reported.