Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0851184 (thinning)
 11,252 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The detection of regional myocardial dysfunction due to acute ischemic event has been limited almost entirely to experimental animal models. In human subjects, it has been limited to the observations during spontaneously-occurring or exercise-induced ischemic events. Recently, percutaneous transluminal coronary angioplasty (PTCA) provides an opportunity to study such dysfunction as the result of repeated interruptions of coronary blood flow. Echocardiograms and electrocardiograms were simultaneously recorded immediately before, during, and after 21 episodes of complete interruptions of coronary blood flow by PTCA in 11 patients. No patient had asynergy of the left ventricle either by two-dimensional echocardiography (2DE) or angiography. All patients had isolated single coronary artery stenosis including the left anterior descending artery in nine, left circumflex artery in one and right coronary artery in one. Recordings of M-mode and 2DE were successfully obtained in 10 patients. After balloon inflation, regional asynergy in the distribution of the instrumented coronary artery appeared in all 10 patients. Hypokinesis developed 9 +/- 3 (means +/- SD) sec after balloon inflation and progressed rapidly to akinesis or dyskinesis. At the same time, decreased systolic thickening of the left ventricular wall appeared in some patients in relation to the development of regional asynergy. However, systolic thinning of the left ventricular wall was not noted in all. The regional asynergy preceded ischemic electrocardiographic changes and had no relation to chest pain. Left ventricular wall motion began to normalize 12 +/- 3 sec after balloon deflation. Thereafter, transient hyperkinesis of the left ventricle developed. The first ischemic electrocardiographic change was a negative U wave which appeared 13 +/- 7 sec after coronary occlusion and remained 3 to 4 sec. Tall T waves were recorded at 28 +/- 12 sec and significant ST elevations developed 31 +/- 11 sec, after balloon inflation. These electrocardiographic changes invariably occurred only after the onset of wall motion abnormalities. Normalization of T waves was recognized at 17 +/- 16 sec and ST segment deviation were no longer present at 18 +/- 10 sec, after reperfusion. These electrocardiographic changes also preceded normalization of regional myocardial dysfunction. In conclusion, left ventricular wall motion abnormalities after coronary occlusion invariably precede the electrocardiographic changes, and begin to normalize after reperfusion prior to the electrocardiographic recovery.
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PMID:[Mechanical and electrocardiographic sequence of coronary artery occlusion: an echocardiographic study during coronary angioplasty]. 296 73

The effect of early chronic Chagas's disease on the timing and extent of regional left ventricular wall motion was studied with a frame by frame analysis of left ventriculograms in nine patients and compared with those in 19 normal subjects. In all the patients there was hypokinesis or akinesis in the anteroapical region together with delay in the onset of inward movement. Hypokinesis of the proximal inferior segment was also present, but the time of onset of inward motion here was normal. These differences can be explained on the basis of regional asynchrony within the normal left ventricle, where anteroapical wall motion is delayed with respect to that elsewhere. Thus contraction of the diseased anteroapical segment starts against an appreciable pressure and so may be isometric, whereas the affected proximal inferior segment starts contracting earlier against a lower pressure and so is able to shorten. No abnormalities of wall motion were seen during isovolumic relaxation despite segmental involvement, which is a distinctly different finding from that in patients with coronary artery disease. This may be due partly to the absence of incoordinate relaxation in Chagas's disease and partly to myocardial involvement by Chagas's disease in the mid-anterior segment. This is the site of rapid early diastolic wall thinning, which has been put forward as a major mechanism of normal rapid ventricular filling and whose premature activity causes disturbances in regional wall motion before mitral valve opening when relaxation is incoordinate. Thus quantitative analysis of both the timing and amplitude of wall motion indicates fundamental differences between Chagas's disease and coronary artery disease, when a less complex analysis would have shown a similar pattern of segmental dysfunction in both. Since the effect of the same pathological process on wall motion varies with the site of ventricular involvement, the importance of the disturbances seen in Chagas's disease becomes apparent only when the non-uniformity of normal left ventricular structure and function is taken into account.
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PMID:Left ventricular wall motion in patients with Chagas's disease. 668 24

A technique for epicardial mapping of segmental myocardial function at multiple sites over both right and left ventricles was developed using a high-resolution, 7.5-MHz, short-focus, miniaturized, M-mode echocardiographic transducer worn on the fingertip. Myocardial function was determined from the extent and time course of systolic thickening and diastolic thinning at each site mapped. The technique was characterized in an open-chest canine model of myocardial ischemia. Ischemia was induced by transient or permanent coronary occlusion in 17 dogs. Acute occlusions produced reduced segmental thickening within 10-15 seconds and, often, overt systolic thinning of ischemic myocardium. Rhodamine fluorescence perfusion maps were compared with echocardiographic maps in nine dogs. Segmental thickening was reduced in perfused segments adjacent to, but not involved by, ischemia, as well as ischemic segments. Reproducibility appeared satisfactory for quantitative analysis of grouped data on multiple segments, and qualitative analysis in individual segments. Initial human studies performed during coronary bypass surgery in 11 subjects showed echocardiographic abnormalities in the six patients with ventriculographic abnormalities and in four with normal ventriculograms. Transmural infarctions were akinetic, showing no change in thickness throughout the cardiac cycle. Hypokinetic segments distal to high-grade coronary stenosis were common, although most segments distal to stenosis contracted normally. Reversal of segmental contraction abnormalities by coronary bypass grafting was shown in three subjects, while worsening of function was seen in previously abnormal segments in two and in a previously normal segment in one subject. Epicardial echocardiographic mapping is a practical method for intraoperative assessment of myocardial function during coronary surgery in man that may enhance our understanding of the pathophysiology of coronary disease and the effects of coronary surgery.
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PMID:Epicardial mapping of segmental myocardial function: an echocardiographic method applicable in man. 698 15