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Although global and regional left ventricular (LV) function has been demonstrated to improve after reperfusion in acute myocardial infarction (AMI), the timing of these changes has not been well established. In this study, serial 2-dimensional echocardiography was used to assess regional LV function in 23 patients with AMI in whom reperfusion was accomplished by thrombolysis alone, by coronary angioplasty alone or by both interventions within 6 hours after onset of chest pain. Echocardiograms were performed before or within 6 hours after reperfusion (n = 23) and at 1 (n = 19), 3 (n = 21) and 7 (n = 20) days after reperfusion. Wall motion index and percentage of normally functioning muscle were calculated using a 16-segment scoring system analyzed in blinded fashion without knowledge of patient identity, therapy or time of study. The mean wall motion index improved from 1.78 +/- 0.48 to 1.56 +/- 0.38 at 1 day (n = 19, p less than 0.01), and to 1.48 +/- 0.37 at 3-7 days (p less than 0.01), with no significant difference between 3 days (1.49 +/- 0.39) and 7 days (1.42 +/- 0.30). There was a corresponding improvement in the percentage of normally functioning muscle, from 53 +/- 24% at 6 hours to 62 +/- 20% at 1 day (p less than 0.05) and to 67 +/- 18% at 3-7 days (p less than 0.01), again with no significant difference between 3 days (67 +/- 21) and 7 days (70 +/- 20).(ABSTRACT TRUNCATED AT 250 WORDS)

A patient with rapidly progressing amyloidosis had cardiac involvement including the unusual echocardiographic appearance of both right and left ventricular outflow tract obstruction, previously unreported in this disease process. Echocardiographic findings were substantiated by autopsy findings of massive biventricular hypertrophy and amyloid deposition in the myocardium.

A regional wall motion index has been derived from two-dimensional echocardiograms by use of a 16-segment model that was subdivided into anterior (nine segments) and infero-postero-lateral (seven segments) regions. This new method is compared with the use of a previously described global wall motion index for the analysis of serial echocardiograms after reperfusion in 23 patients who had acute myocardial infarction. Mean global index improved from 1.84 +/- 0.46 to 1.56 +/- 0.37 at 24 hours (p less than 0.01) and to 1.50 +/- 0.29 after 3 days to 7 days (p less than 0.02), whereas mean regional index for infarct regions improved from 2.28 +/- 0.73 to 1.82 +/- 0.58 at 24 hours (p less than 0.01) and to 1.70 +/- 0.42 after 3 to 7 days (p less than 0.01), with no significant change in the noninfarct index (1.34 +/- 0.32 initially and 1.28 +/- 0.36 after 3 to 7 days). Although both global and regional indexes effectively demonstrate early recovery of left ventricular function, (within 24 hours in many patients), the regional index for infarct regions is higher than the global index and effectively distinguishes between infarct and noninfarct segments. An overlap index in which an additional apical segment is included in the anterior region (10 segments) for anterior infarctions and in the infero-postero-lateral region (eight segments) for inferior infarctions results in a greater differentiation between infarct and noninfarct regions, with the mean initial noninfarct overlap index (1.17 +/- 0.33) significantly less than the nonoverlap index.(ABSTRACT TRUNCATED AT 250 WORDS)

The ability of contrast-enhanced echocardiography to localize and quantify myocardial infarction was studied in 16 open chest dogs. Both routine and contrast-enhanced two-dimensional echocardiograms were recorded at baseline and 4 hours after occlusion of the left anterior descending (n = 11) or circumflex (n = 5) coronary artery. Ultrasound contrast was produced by injection into the aortic root of 3 ml of 0.3% hydrogen peroxide mixed with 6 ml blood. Systolic wall thickening was also measured and quantified as a marker of myocardial infarction. Dogs were sacrificed after 4 hours of coronary occlusion. The slice of the left ventricle that corresponded to the two-dimensional echocardiogram was stained with nitro-blue tetrazolium to localize the infarct. The size of the myocardial infarct was determined by planimetry.The oxygen bubbles produced by mixing hydrogen peroxide with blood produced an excellent intramyo-cardial ultrasound contrast effect. Complete data were available in 12 dogs. Contrast echocardiography accurately localized the infarction in all 11 dogs with an infarct documented by nitro-blue tetrazolium. The area of the infarct, determined by planimetry and expressed as a fraction of total myocardial area from the nitro-blue tetrazolium study, correlated well with the size of the infarct determined with contrast echocardiography (correlation coefficient [r] = 0.92, standard error of the estimate [SEE] = 0.05, probability [p] < 0.001). Intra-and interobserver correlations were excellent for the determination of fraction of infarcted myocardium by contrast echocardiography (r = 0.93, p < 0.001, SEE = 0.04; r = 0.89, p < 0.001, SEE = 0.07, respectively). Absence of systolic wall thickening also accurately localized myocardial infarction, but correlated poorly with the extent of infarction (r = 0.29, p = not significant).It is concluded that contrast-enhanced two-dimensional echocardiography, using a combination of hydrogen peroxide and blood to provide ultrasound contrast, accurately and reproducibly localizes and quantifies myocardial infarction.

In this study we used myocardial contrast echocardiography to evaluate reperfusion hyperemia in an open-chest canine model of temporary coronary artery occlusion. Eight dogs had coronary occluders and electromagnetic flow probes on the left circumflex coronary artery. Aortic root injections of agitated sodium diatrizoate and saline solution were used for myocardial contrast. Data were collected at baseline (n = 16), during coronary occlusion (n = 18), immediately after coronary release (n = 18), and 5 minutes after coronary artery release (n = 12). Baseline coronary flow was 23.8 +/- 5.9 ml/min, decreasing to 0 ml/min during coronary occlusion. Immediately after coronary release flow was 96.6 +/- 41 ml/min (p less than 0.001 compared with baseline), and 5 minutes after coronary release flow was 68.2 +/- 27.9 ml/min (p less than 0.001 compared with baseline). The myocardial image intensity change after injection of contrast material was 74.25 +/- 30.6 ml/min at baseline and declined to 10.4 +/- 10.9 ml/min during coronary occlusion (p less than 0.001 compared with baseline). During reperfusion hyperemia image intensity change was 102.3 +/- 33.3 ml/min (p less than 0.001 compared with occlusion, p less than 0.02 compared with baseline, p less than 0.001 compared with remote regions). Considering all observations, myocardial image intensity change after contrast injection correlated positively with coronary flow (r = 0.67, p less than 0.001). Correlations within individual dogs ranged from r = 0.70 to 0.98. We conclude that image intensity change after aortic root injection of echocardiographic contrast correlates with coronary blood flow. Objective measurements of contrast intensity reflect increases in coronary flow associated with reactive hyperemia after coronary occlusion and release.

To evaluate the role of quantitative two-dimensional echocardiography (2DE) in the preoperative assessment of patients undergoing left ventricular (LV) aneurysmectomy, we identified 37 patients who were studied with 2DE 1 to 56 (mean 12.6) days prior to surgery. Diastolic (Dd) and systolic (Ds) minor-axis dimensions at the base were measured and fractional shortening (FS) was calculated. Global and basilar half ejection fraction (EF) as measured from right anterior oblique left ventriculograms. At follow-up (mean 17.9 months), 27 patients were alive and clinically improved (group A) and 10 patients either died or were symptomatically unimproved (group B). Basilar half EF was significantly greater among patients in group A (0.50 +/- 0.09) than in group B (0.37 +/- 0.10) (p less than 0.001). Echocardiographic FS provided the best separation between groups. Mean FS was 0.25 +/- 0.06 in group A and 0.15 +/- 0.04 in group B (p less than 0.001). All seven patients with FS less than 0.17 were in group B while 25 of 27 patients with FS greater than 0.17 were in group A (p less than 0.001). Considering all patients, basilar half EF and FS were highly correlated (r = 0.84).

The transport characteristics of muscle interstitial space were determined using an isolated rat diaphragm preparation. Permeability of the interstitial space for extracellular solutes is one-thirtieth to one-fiftieth that of an equivalent thickness of water. However, most of this low permeability can be accounted for by correcting for the tortuosity and relative volume of interstitial space. The estimated diffusivity of solutes (mol. wt. 100-70,000) in the interstitial space of muscle is only about one-half to one-fifth less than in water alone.

The perfluorocarbon Fluosol DA has been reported to increase the subjective echogenicity of infarcted myocardium. To investigate this phenomenon, two-dimensional echocardiograms were recorded in 20 closed-chest dogs before and 24,48,72, and 96 h following permanent coronary artery occlusion. Low-dose Fluosol, 10 ml/kg (LDF) (four dogs), high-dose Fluosol, 25 ml/kg (HDF) (eight dogs), or lactated Ringers 25 ml/kg (LR) (eight dogs) was administered 48 h after occlusion. Left ventricular sections corresponding to the short-axis echocardiographic examination plane were stained with nitroblue tetrazolium 48 h after Fluosol administration. Short-axis echocardiographic studies were evaluated by two blinded observers who found no consistent increase in the echogenicity of the infarcted area in any group. Videodensitometry of the infarcted area, normalized to the average value of two remote areas, confirmed mean post-Fluosol increases of 66% in LR dogs, 65% in LDF dogs, and 107% in HDF animals (p less than 0.001 for all dogs; all intergroup comparisons NS). The increase in videodensity observed in all groups may have occurred as a consequence of volume administration, although changes in infarct intensity occurring over time cannot be excluded.

Upright bicycle exercise echocardiography and coronary angiography were performed in 42 patients from 1 month to 15 years (mean 6.3 years) after coronary artery bypass grafting (CABG) to determine if exercise-induced wall motion abnormalities could be correlated with the presence and location of nonrevascularized vessels. Nonrevascularized vessels were defined as obstructed vessels without grafts, obstructed grafts or native vessels obstructed distal to bypass graft insertion. Adequate quality echocardiograms were recorded at rest, peak exercise and after exercise in 38 patients (90%). Rest and postexercise echocardiograms were adequate in 3 others. Only 1 patient was excluded from analysis for inadequate peak and postexercise echocardiograms. Exercise-induced wall motion abnormalities were present in 33 of 35 patients (94%) who had 1 or more nonrevascularized vessels and these abnormalities were absent in 5 of 6 (83%) who had all vessels revascularized. Wall motion abnormalities were localized to the territory of the left anterior descending (LAD) artery or to a combined right (R) coronary-left circumflex (LC) region of circulation. Exercise-induced wall motion abnormalities were present in 24 of 27 LAD artery regions (89%) and 23 of 26 R-LC regions (88%) that had nonrevascularized vessels. These abnormalities were absent in 13 of 14 LAD regions (93%) and in 12 of 15 R-LC regions (80%) that had only revascularized vessels. Upright bicycle exercise echocardiography was successfully performed after CABG. The technique detected and accurately localized nonrevascularized and revascularized vessels.

Left ventricular pseudoaneurysm represents a cardiac rupture which is temporarily confined by pericardium and is amenable to curative surgical treatment. The case described illustrates several atypical features of its presentation and diagnosis, highlighting the importance of maintaining a sufficient clinical index of suspicion for this relatively uncommon, but potentially lethal entity. The use of various diagnostic imaging methods is described, including the first description of magnetic resonance imaging of ventricular pseudoaneurysm. The prospect of medical therapies directed toward the prevention of cardiac rupture, and thus pseudoaneurysm, is discussed in the context of its pathophysiology which involves alterations in the cardiac fibroskeletal support.

Excerpt Continuous ambulatory electrocardiographic monitoring was introduced in the 1960s and has become a common technique for evaluating arrhythmias in patients with a wide variety of cardiac dis...

Two-dimensional echocardiograms were done during rest and after exercise in 95 patients who subsequently had coronary arteriography. Prior myocardial infarction was present in 36 patients, 35 of whom had wall motion abnormalities. There was no evidence of prior infarction in 59 patients, 44 of whom had coronary disease. In these 44 patients, the exercise electrocardiogram showed ischemia in 19, was normal in 13, and was nondiagnostic in 12. Exercise echocardiograms were abnormal in 35 of these 44 patients. In 15 patients without coronary disease, the treadmill response was nondiagnostic in 6, ischemic in 1, and normal in 8. Exercise echocardiograms were normal in 13 of these 15 patients. We conclude that exercise echocardiography is a valuable addition to routine treadmill testing. It may be of special value in patients with an abnormal resting electrocardiogram or a nondiagnostic response to treadmill testing or when a false-negative treadmill test is suspected.