Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:4.1.1.6 (CAD)
 4,420 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Dynamic ventriculography, before and after K-strophantin, was performed in 14 patients with coronary artery disease. Qualitative and quantitative evaluation of hemodynamic and angiographic data has been assessed. Digitalis was found to have different action on asynergic areas--that is improvement in some areas and worsening in others--and little or no action on normokynetic areas. After administration of K-strophantin (0.008 mg/kg), 54% of the examined asynergic zones improved their segmental systolic shortening while 34% worsened or appeared diskynetic. Improvement of asynergic zones could be related to the presence of viable myocardium, while paradoxical systolic motion would suggest the presence of frank fibrosis. Therefore 2 different behaviors of global ventricular function were observed in CAD patients. When ventricular function improves, the values of ejection fraction at midejection show that the improvement is obtained mostly in the first half of ejection. Since heart rate was fixed, enddiastolic volume unchanged and left ventricular systolic pressure increased, it seems likely that the observed changes could be due to a direct inotropic effect of K-strophantin. The author's opinion is that 'strophantin test' could be useful to test whether ventricular function would be enhanced using maintenance digitalis therapy in CAD patients and to determine residual contractile reserve; in addition potential worsening of ejection fraction can be elicited and then a more complete pattern of ventricular function can be provided.
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PMID:Dynamic ventriculography with K-strophantin. 68 71

In 107 patients having coronary artery disease in their majority, left ventricular ejection fraction and minimal cardiac transit times (MTT) were determined by precordial registration during the first passage of the radioactive tracer. 87 patients underwent echocardiographic examination. Data were compared with ventriculography and coronarography: left ventricular ejection fraction, if radiographically evaluated, shows a low sensitivity in indicating myocardial disorder. MTTs are reduced in more than 80% of patients with CAD at rest. With a few exceptions, all patients with disorders in the ventriculogram show reduced MTT values. MTTs, however, do not react specifically for myocardial performance. They also indicate disorders of central hemodynamics caused by vitia cordis. In these cases myocardial function can not be evaluated. Echocardiography can only be applied in about 85% of patients. It possesses a high sensitivity in discrimination of lower degree failures. Results are misleading in old infarctions with dyskinesia. It is concluded that best diagnostic information concerning global myocardial function results if direct hemodynamic parameters as MTT are combined with echocardiography.
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PMID:[Radiocardiographic procedures during the first passage of an intravascular tracer in diagnostic context with echo- and angiocardiography (author's transl)]. 73 85

72 patients with CAD, 10 patients with congestive cardiomyopathies and 10 normal subjects were evaluated by radionuclide angiography. Comparison with contrast angiography showed good results for LVEF (r = 0.83). Regional asynergies observed in the radionuclide angiography correlated well with defects in thallium scintigrams. Extent of abnormal wall motion was measured and compared with normals, appreciating the deviation from the normal mean radial shortening. Good correlation could be demonstrated with radionuclide ventriculography. In 80% of congestive cardiomyopathies the right ventricle wall became visible in the thallium scintigram.
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PMID:Assessment of regional wall motion in coronary artery disease using radionuclide methods. 73 91

A "real-time" ECG-gated scintigraphic image system was developed at NIH, Bethesda. This system presents in real-time manner 1) an image sequence, that spans a complete heart cycle, 2) a regional time activity curve, in which later distolic phenomena are correctly portrayed, and 3) a beat length distribution function. This system is suitable especially for stress investigations. Normal subjects showed an increase of ejection fraction, whereas patients with CAD revealed a decrease of EF.
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PMID:Radionuclide cineangiography during stress. 73 93

Angiographically determined changes in segmental wall motion (SWM) and ejection fraction (EF) are sensitive indices of left ventricular (LV) function. To compare the effects of exercise on LV function, first pass radionuclide angiocardiography was used before and during maximal upright bicycle stress in patients with nonsignificantly stenosed coronary arteries, and in those with greater than 75% stenosis. Gamma camera acquisitions were made in the 30 degree RAO projection using a 20 mCi I.V. bolus of 99mTc-pertechnetate. In the control group (seven normals, one nonsignificant (CAD) the EF significantly increased between rest and exercise (0.65 +/- 0.03 to 0.81 +/- 0.03 (mean +/- SEM), p less than 0.005). In this group SWM measured over the two anterior and two inferoposterior segments uniformly increased. In the 11 patients with a history of angina and significant coronary artery obstruction, the EF did not change in three and significantly decreased in the remaining eight (0.57 +/- 0.04 to 0.45 +/- 0.03, p less than 0.005). In all 11 patients SWM either decreased or did not increase in the areas supplied by the significantly stenosed coronary arteries. Upright maximal stress angiocardiography appears to be well-suited for diagnosing ischemic heart disease and localizing the area of ischemic dysfunction.
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PMID:Effects of maximal exercise stress on left ventricular function in patients with coronary artery disease using first pass radionuclide angiocardiography: a rapid, noninvasive technique for determining ejection fraction and segmental wall motion. 75 25

It is apparent that a variety of factors may be responsible for myocardial ischemia, and even infarction, in the absence of occlusive major vessel coronary disease. In particular, it must be emphasized than angina-like chest pain may well have its origin in myocardial ischemia, even in younger patients with unusual patterns of chest pain but without predisposition to premature CAD. Increasing awareness of disorders such as coronary arterial spasm, functional impairment of subendocardial blood flow and the possible role of variant patterns of anatomic distribution of the coronary arterial tree, will provide a better understanding of their significance as determining or contributing factors in patients with the anginal syndrome.
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PMID:The anginal syndrome without evidence of coronary artery disease. 76 88

In 10 patients without and 20 patients with various degrees of angiographically proven CAD 93 pacing runs were studied. Changes of PAm, of ECG, and of anginal pain serving as parameters of myocardial ischemia were correlated to the rate-pressure-product. In patients without CAD no correlations could be ascertained. In each patient with CAD determination of ischemia was achieved reproducibly. Ischemia threshold is represented by a sharp increase of PAm. Ischemia threshold seems a parameter to be preferred as compared to pain threshold. The extent of CAD (angiographically estimated) correlates well with the pacing test especially when collaterals are taken into account. After NG no substantial improvement of ischemia can be detected: Ischemia threshold before and after NG was reached at same rate pressure in each case. We conclude the atrial pacing test to be an excellent test for the provocation of myocardial ischemia. The test is also useful for estimation of the extent of CAD.
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PMID:Pacing-induced myocardial ischemia in spite of nitroglycerin. Correlations regarding the extent of coronary artery disease. 80 82

To clarify the influence of propranolol-and particularly its heart-rate effects-on myocardial ischemia, coronary hemodynamics and metabolism were studied in 15 patients utilizing a protocol to control heart rate. Ten patients had significant coronary narrowing (CAD) and 5 were normal. Systemic pressure, coronary sinus blood flow (CSBF), left ventricular oxygen utilization (LVVO2), ST Segment depression, and myocardial lactate extraction were measured before and after propranolol (10 mg IV), at rest, during pacing-induced tachycardia stress. Propranolol-related reduction in CSBF and LVVO2 at rest was reversed when heart rate was controlled in both patient groups. Propranolol failed to alter heart-rate threshold, tension-time index (TTI), CSBF, or LVVO2 at angina in the CAD patients. Likewise, ischemic-type ST depression, decreases in lactate extraction, and coronary resistance were unchanged compared to values observed during tachycardia stress before propranolol. In normal coronary patients, propranolol also produced no significant change in LVVO2 or coronary resistance when its heart rate effects were controlled. These data imply that a major coronary and metabolic influence of propranolol relates to changes occurring secondary to its influence on heart rate. Furthermore, this agent's anti-ischemic effect is not prominent during tachycardia stress suggesting that this stress test may be clinically useful in patients taking propranolol.
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PMID:Effects of propranolol on coronary hemodynamic and metabolic responses to tachycardia stress in patients with and without coronary disease. 83 33

In summary, near-maximal or maximal exercise testing has a sensitivity of approximately 60% and a specificity of approximately 90% for coronary atherosclerotic heart disease. When screening asympatomatic men with exercise testing, an abnormal response identifies a group of men at very high risk for coronary artery disease. However, the predictive value limitations are obvious and the false-positive problem must be realized. At present, there is no second line of noninvasive studies that can separate an exercise-test false positive from a true positive with certainty. Risk-factor consideration may help separate them; The sensitivity limitations of exercise testing must be especially considered when evaluating people at high risk for CAD. An abnormal test response does not absolutely predict the presence of CAD and a normal response does not rule out its possibility. In appropriate instances where coronary angiography can be performed at minimal risk and when it is justified for reasons of public safety or individual well-being, this procedure can give a reasonably definitive answer. Creation of iatrogenic "cardiac cripples" can be the most common complication of screening tests and should be avoided. Therefore, good clinical judgment needs to be used in conjunction with any screening test.
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PMID:The detection of asympatomatic coronary artery disease. 85 28

In 32 patients with angiographically proved CAD the diffusion parameters of the lung (intracapillary pulmonary blood volume, Vc, and diffusion capacity of the alveolo-capillary membrane, Dm, respectively the reciprocal value membrane resistance) were measured. As reference the pre-a-LVDP was used, as it represents more adequately than the LVEDP the pressure acting on the alveolo-capillary membrane. There was a significant positive correlation between the Vc and the pre-a-LVDP as well as a highly significant positive correlation between the diffusion resistance of the alveolo-capillary membrane and the pre-a-LVDP. This corresponds to a pulmonary congestion with an increase of Vc and an interstitial edema with an increase of the diffusion resistance of the alveolo-capillary membrane. The Dco may be unchanged in spite of a marked increase of LVDP, since the decrease of the membrane component is accompanied by an increase of the blood component of diffusion. Only the differentiation of the CO-transfer in its components Vc and Dm gives an information about changes of the hemodynamics in CAD.
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PMID:Changes of the CO-diffusing components of the lung in patients with coronary artery disease (author's transl). 91 71


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