Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0151814 (coronary occlusion)
 3,687 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The widespread use of cardiac ventriculography has focused interest on the frequency with which asynergy accompanies coronary heart disease as well as on its clinical and prognostic implications and dynamic nature. Recently, "intervention ventriculography" using nitroglycerin or postextrasystolic potentiation has indicated that asynergic zones may be more accurately classified as reversible (implying viable myocardium) or irreversible (nonviable or scarred myocardium), and thus the ventriculographic definition of aneurysm must reflect not only the severity of asynergy but its contractile reserve. Surface electrocardiogram Q waves, the severity of asynergy, and degree of coronary occlusion all adversely affect the potential for reversibility, whereas coronary collaterals enhance it. Important clinical applications include assessment of the potential utility of coronary bypass surgery in improving asynergy and of vasodilators in the treatment of patients with left ventricular failure. With refractory sequelae of aneurysms (heart failure, ventricular tachyarrhythmias, and systemic emboli) and a discrete aneurysm, surgical resection has been increasingly used with generally good results.
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PMID:Asynergy in coronary heart disease. Evolving clinical and pathophysiologic concepts. 41 Mar 36

Electrocardiograms and Frank vectorcardiograms were recorded in 156 consecutive patients with total occlusion of at least one coronary artery (on arteriography) and associated left ventricular contraction abnormality (on ventriculography). The angiograms and cardiograms were independently reviewed. In the presence of single vessel occlusion, appropriate vectorcardiographic diagnosis of myocardial infarction was determined in 118 of 156 cases (76 percent) compared with a lower electrocardiographic detection rate in 77 of 156 cases (49 percent). Findings diagnostic of two coexisting infarctions were observed in 71 percent of vectorcardiograms and 37 percent of electrocardiograms in 51 patients with double vessel occlusion and two areas of left ventricular dyskinesia. The vectorcardiographic detection rate was similarly superior to the electrocardiographic rate in the presence of subtotal coronary occlusion and myocardial asynergy in single (73 percent versus 53 percent) and double (53 percent versus 28 percent) vessel disease. The incidence rate of false positive diagnoses was 3 percent for electrocardiography and 4 percent for vectorcardiography. It is concluded that the vectorcardiogram is superior to the electrocardiogram in the diagnosis of obstructive coronary artery disease and left ventricular contraction abnormality.
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PMID:Correlation of electrocardiogram and vectorcardiogram with coronary occlusion and myocardial contraction abnormality. 98 55

To evaluate the influence of the native coronary circulation on the reversibility of asynergy, ventriculograms before and after sublingual nitroglycerin were performed in 51 patients with coronary artery disease and asynergy. The severity of stenotic lesions and caliber of the distal coronary vessels were determined by comparison with external catheter tip diameter corrected for magnification. Of 42 asynergic zones associated with larger than or equal to 90% proximal coronary occlusion, 27 (64%) were akinetic or dyskinetic while only 11 of 38 zones (29%) with less than 90% occlusion showed akinesis (P less than 0.005). Twenty-six of the 38 asynergic zones (69%) with less than 90% occlusion were reversible in contrast to 19 of the 42 zones (45%) with larger than or equal to 90% occlusion (P less than 0.05). Coronary collaterals were observed in 23 of 42 (55%) zones with larger than or equal to 90% occlusion in contrast to only 11 of 38 zones (29%) with less than 90% occlusion (P less than 0.05). Of the zones with both greater than or equal to 90% occlusion and collaterals, 74% were reversible, in contrast to only 11% without collaterals (P less than 0.001). Of the asynergic zones without collaterals, 63% with less than 90% occlusion were reversible in contrast to only 11% with larger than or equal to 90% occlusion (P less than 0.001). Pathologic Q waves were associated with 24 of 42 zones (57%) with larger than or equal to 90% occlusion compared to only nine of the 38 zones (24%) with less than 90% occlusion (P less than 0.01). The presence of Q waves was associated with a significant decrease in the incidence of reversibility regardless of the degree of coronary occlusion. Excluding the asynergic zones with either collaterals or Q waves, 79% with less than 90% occlusion were reversible in contrast to only 37% with larger than or equal to 90% coronary occlusion (P less than 0.05). In contrast, the caliber of the distal vessel could not be correlated with either the severity of asynergy or the presence of collaterals and was similar in both reversible and irreversible asynergic zones. In summary, larger than or equal to 90% proximal stenosis is associated with severe asynergy which is less likely to be reversible compared to asynergy associated with less than 90% coronary occlusion. In the presence of larger than or equal to 90% occlusion, coronary collaterals are associated with a significantly higher incidence of reversible asynergy and thus appear to serve a protective function. However, the caliber of the distal vessel per se does not effect the severity or reversibility of asynergy.
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PMID:Determinants of reversible asynergy. The native coronary circulation. 108 Jun 96

Effects of beta-adrenergic blockade on regional myocardial dysfunction induced by coronary artery occlusion were studied in chronically instrumented, conscious dogs before (n = 8) and after (n = 7) collateral development. Intravenous atenolol or propranolol produced no beneficial effects on systolic shortening in the area rendered ischemic during 2 minutes of circumflex occlusion, before collateral development. After the collateral development by repetitive 2-minute coronary occlusions, regional asynergy recovered to the preocclusive level during 2 minutes of occlusion. Both atenolol and propranolol significantly improved the peak reductions of regional shortening by 19 +/- 9% and 18 +/- 9%, respectively (p less than 0.05 versus without beta-blockade). These beneficial actions of beta-blockade were again noted during atrial tachypacing at matched heart rates of 160 +/- 11 beats/min. Thus the beneficial effects of beta-blockade on regional asynergy during coronary occlusion depend on the level of functional state of the collaterals and cannot be totally accounted for by the reduction in heart rate or by the cardioselectivity.
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PMID:Amelioration by beta-adrenergic blockade of regional myocardial dysfunction induced by coronary artery occlusion after, but not before collateral development in conscious dogs. 291 89

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.
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PMID:Two-dimensional echocardiography during percutaneous transluminal coronary angioplasty. 294 Aug 52

We have shown improvement in collateral filling immediately after sudden controlled coronary occlusion in human subjects undergoing elective coronary angioplasty. It has been suggested but not proved that collateral circulation can limit myocardial ischemia. We prospectively studied 23 patients with isolated left anterior descending (n = 14) or right coronary (n = 9) disease and normal left ventriculograms during elective coronary angioplasty. A second arterial catheter was used for injection of the contralateral artery to assess collateral filling before balloon placement and during coronary occlusion by balloon inflation. Left ventriculography was performed during another inflation. Grading of collateral filling was as follows: 0 = none, 1 = filling of side branches only, 2 = partial filling of the epicardial segment, 3 = complete filling of the epicardial segment. Indexes of myocardial ischemia included percent of the left ventricular perimeter showing new hypocontractility and the sum of ST segment elevation measured on a simultaneous 12-lead electrocardiogram recorded during each inflation. Collateral filling during balloon occlusion and indexes of ischemia were assessed at 30 to 40 sec into inflation. Aortic pressure and heart rate did not correlate with the percent hypocontractile perimeter nor the sum of ST segment elevation. There was a significant correlation between the grade of collateral filling during inflation and both percent hypocontractile perimeter (r = -.85) and the sum of ST segment elevation (r = -.87). Anginal pain occurred in all patients with grade 0 or 1 collateral filling but in only 36% of patients with grade 2 or 3 collaterals. In conclusion, collateral circulation limits myocardial ischemia as assessed by the extent of new ventricular asynergy and electrocardiographic changes during coronary occlusion in patients.
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PMID:Limitation of myocardial ischemia by collateral circulation during sudden controlled coronary artery occlusion in human subjects: a prospective study. 294 29

To assess the usefulness of different electrocardiographic variables as markers for the presence, extent and location of new wall motion abnormalities seen after sudden controlled coronary occlusion, 23 patients with isolated left anterior descending (n = 12), or right (n = 11) coronary artery disease and a normal baseline left ventriculogram were prospectively studied during transluminal coronary angioplasty. A simultaneous 12 lead electrocardiogram was recorded before passing the balloon catheter and again at 30 seconds into the fourth inflation cycle. Using a second arterial catheter, a left ventriculogram was obtained at 40 seconds into the fourth inflation cycle. The extent of wall motion abnormalities was described as the percent of left ventricular perimeter showing hypocontractility. During balloon inflation, 19 of the 23 patients developed new hypocontractility ranging from 3 to 40%. ST segment elevation in lead V2 was the most sensitive marker for anterior wall hypocontractility and ST segment elevation in lead III was the most sensitive marker for inferior wall hypocontractility. Highly significant correlations were observed between the extent of the hypocontractile perimeter and 1) the sum of ST segment elevation in all 12 leads; 2) the magnitude of ST segment elevation in either lead V2 or lead III; and 3) the total number of leads with ST elevation greater than or equal to 0.5 mV. No significant changes were seen in the sum of R wave amplitudes, but a significant prolongation of the QT interval was seen during ischemia. In conclusion, acute ST segment elevation parallels the development of new asynergy during transluminal coronary angioplasty.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Prospective analysis of electrocardiographic variables as markers for extent and location of acute wall motion abnormalities observed during coronary angioplasty in human subjects. 295 16

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

In 73 patients with acute occlusion of single coronary artery, the authors assessed the possibilities of ECG and echocardiography in determining non-invasively which of the 3 main arteries had been occluded. The sensitivity of ECG for the individual arteries and particular ECG signs ranged between 30-98%, the specificity was between 86-100%. While it was always possible to determine occlusion of the left anterior descending coronary artery (LAD), in several cases it was difficult to distinguish between occlusion of the left circumflex (LCX) and the right coronary artery (RCA). The LCX occlusion is a frequent source of error in interpreting electrocardiograms of patients with fresh myocardial infarction. The sensitivity of echocardiography in identifying the occluded coronary artery ranged between 77-100%, specificity 97-100%. The following ECG and echocardiographic signs of coronary occlusion were determined. The LAD occlusion is indicated by ECG changes in V1-4, and anteroseptal and apica asynergy on echocardiography. LCX occlusion: increased R wave amplitude in V1, and lateral and posterior wall asynergy. The RCA occlusion: ECG changes in II, III, aVF, asynergy of the posterior wall and part of the septum and right ventricle. These combined signs make possible the identification the occluded coronary artery in 95% of patients with myocardial infarction.
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PMID:The possibility of non-invasive identification of occluded coronary artery in acute myocardial infarction. A comparison of ECG and echocardiography with coronary arteriography or autopsy. 382 88

The authors report on 18 patients with fresh transmural myocardial infarction (MI) and 5 patients with an abrupt change of stable into unstable angina pectoris (AP), in whom superselective intracoronary thrombolysis (SIT) was performed. All patients with unstable AP showed an improvement of subjective complaints and increased tolerance of exercise, even though a demonstrable angiographic effect of SIT was found only in 1 patient. Coronary occlusion disappeared in 13 patients with MI (72%). A significant improvement of local kinetic disturbances and of the global left ventricular function occurred in 50%, in-hospital death occurred only in the group in which recanalization did not succeed. Emphasis is placed on the necessity of checking the effect of SIT not only by documenting correction, of the coronary occlusion but also by evaluating the size of MI and the extent of disturbances of local and total left ventricular kinetics. The most accurate and practical method for this purpose is two-dimensional echocardiography. The authors developed their own echocardiographic indicators of the infarction focus--asynergy extent and asynergy index.
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PMID:Intracoronary thrombolytic treatment in myocardial infarction and unstable angina pectoris. 399 90


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