摘要:

International statistics indicate that there is a close correlation between the consumption of saturated fats (dairy fats and meat fats) and the mortality from coronary heart disease (CHD), and this conception has been confirmed by many epidemiological studies. Such studies alone, however, cannot prove the existence of a cause-and-effect relationship between these two variables; dietary intervention trials are needed.The Finnish Mental Hospital Study was such a trial, conducted in two hospitals near Helsinki in 1959-1971. Practically total replacement of dairy fats by vegetable oils in the diets of these hospitals was followed by a substantial reduction in the mortality of men from CHD. Total mortality also appeared to be reduced. As to the causes of death other than CHD, none was significantly influenced by dietary change. This was also true for malignant neoplasms.To alleviate the burden of CHD on public health, many investigators have recommended important changes in the quantity and quality of dietary fats.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

The impact of cardiovascular disease was compared in non-diabetics and diabetics in the Framingham cohort. In the first 20 years of the study about 6% of the women and 8% of the men were diagnosed as diabetics. The incidence of cardiovascular disease among diabetic men was twice that among nondiabetic men. Among diabetic women the incidence of cardiovascular disease was three times that among nondiabetic women.Judging from a comparison of standardized coefficients for the regression of incidence of cardiovascular disease on specified risk factors, there is no indication that the relationship of risk factors to the subsequent development of cardiovascular disease is different for diabetics and non-diabetics. This study suggests that the role of diabetes as a cardiovascular risk factor does not derive from an altered ability to contend with known risk factors

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Mechanisms involved in the altered left ventricular (LV) diastolic properties during angina were studied in 26 patients with coronary artery disease. Angina was induced by rapid atrial pacing and measurements were made at rest and during angina in the immediate post-pacing period. No changes occurred in heart rate (71 ± 3 to 73 ± 3 beats/min, NS) or right ventricular (RV) end-diastolic pressure (10 ± I to 11 ± 1 mm Hg, NS), while significant increases occurred in LV end-diastolic pressure (17 i 1 to 30 ± 1 mm Hg, p lt; 0.01), aortic diastolic pressure (74 ± 3 to 80 ± 3 mm Hg, p lt; 0.01), coronary sinus blood flow (133 ± 15 to 212 ± 32 ml/min, p lt; 0.01), and the time constant (T) of LV pressure fall in early diastole (43 ± 2 to 58 ± 4 msec, p lt; 0.01). Despite the rise in arterial pressure, a significant fall was observed in peak negative dP/dt (1961 ± 106 to 1751 ± 80 mm Hg/sec, p lt; 0.01). Changes in RV end-diastolic pressure do not explain the increased LV end-diastolic pressure during angina. Increased aortic pressure and coronary blood flow may contribute, but the simultaneous fall in peak negative dP/dt and rise in T suggest that impaired ventricular relaxation is an important factor contributing to the previously demonstrated alteration in LV diastolic properties during angina pectoris.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

To clarify the mechanism of displacement of the left ventricular diastolic pressure-volume function with alteration of loading conditions, the effects of nitroglycerin on pressure-volume relations in 13 patients were compared with those of amyl nitrite in 13 other patients during cardiac catheterization. After nitroglycerin, average systemic mean arterial pressure declined by 15.1 mm Hg (17%) and left ventricular enddiastolic pressure by 9.4 mm Hg (49%); right ventricular systolic and end-diastolic pressures fell 11.6 mm Hg (36%) and 5 mm Hg (41%), respectively. In all patients diastolic pressure-volume curves were significantly displaced downward and leftward. After amyl nitrite, average systemic mean arterial pressure fell 20.1 mm Hg (22%), but left ventricular end-diastolic pressure and right ventricular systolic and end-diastolic pressures were not significantly reduced. No significant displacement of diastolic pressure-volume curves occurred. Both the rate constant of the exponentially fit diastolic pressure-volume curve, and the rate of diastolic isovolumic relaxation (T) were unchanged after each drug. Thus downward displacement of diastolic pressure-volume functions after nitroglycerin appears to be dependent more upon reduction of right ventricular filling dynamics than coronary perfusion pressures. More favorable effects upon left ventricular function may be associated with reduction of both left ventricular filling pressures and systemic impedance (reflecting both "preload" and "afterload") than of systemic arterial pressures ("afterload") alone.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

We measured aortic and coronary sinus dopamine (DA), epinephrine (E), and norepinephrine (NE) in eight patients with cardiac ischemia (I) and eight control subjects (C). Samples were taken at rest (73 ± 3 beats/min in C and 68 ± 3 beats/min in I) and during coronary sinus pacing to peak rates (144 ± 4 beats/min in C and 136 ± 6 beats/min in I). Arterial NE was higher in the ischemic patients at rest (254 ± 25 pg/ml in C and 324 ± 21 in I; p lt; 0.05). There were no differences in arterial E and DA. Neither pacing nor angina affected peripheral catecholamine concentrations. Resting myocardial NE flux was similar for both groups. With pacing, coronary sinus flow and net myocardial NE release increased significantly in both groups. The maximum relative increase in net myocardial NE release was less in the ischemic patients than in the controls (575 ± 145% in C and 255 ± 40% in I; p lt; 0.05). Thus, angina induced by pacing does not augment peripheral sympathetic activity. Furthermore, pacing-induced angina appears to be associated with a decrease in cardiac sympathetic tone compared with that found in paced controls.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

The coronary venous efflux of lactate, inosine and hypoxanthine during pacing-induced angina has been compared with myocardial extraction of the catabolites during exercise-induced angina. Inosine and hypoxanthine were analyzed by enzyme assay after separation by column chromatography.Myocardial lactate extraction at rest (15 ± 9%, mean ± SD) was converted to production levels (-34 ± 26%) during pacing-induced angina (p lt; 0.0005) and increased (24 ± 13%) during exercise (p lt; 0.05). The arterial values at rest (850 ± 330 Amol/1) were unchanged during pacing and increased fivefold during exercise (4380 ± 1860μumol/l). The mean myocardial inosine extraction at rest (33 ± 10%) was transformed to release values (-41 ± 30%) during pacing (p lt; 0.0005) as well as during exercise (-20 + 27%) (p lt; 0.0005). The hypoxanthine extraction at rest (25 ± 11%) decreased during pacing (-7.8 29%) (p lt; 0.0025) and exercise (10 ± 25%) (NS). The slight increase of arterial inosine and hypoxanthine values was not significant. Myocardially produced lactate, a sensitive marker of pacing-induced ischemia, was obscured by elevated arterial concentrations during exercise. However, inosine significantly correlated with lactate during pacing, and was useful in detecting ischemic myocardial energy deficiency during exercise-induced angina.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

To assess the feasibility of detecting wall motion abnormalities with echocardiography during exercise-induced ischemia, we performed echocardiograms on 13 patients with angiographically documented coronary artery disease at rest and during supine bicycle exercise at increasing work loads until angina or ischemic electrocardiographic changes appeared. We analyzed echocardiographic indices of regional left ventricular function in these patients and 11 age- and heart rate-matched normal volunteers. In the 13 patients, 22 of 25 echocardiographically defined wall segments (13 septa, nine posterior left ventricular walls) were supplied by coronary arteries with > 70% stenosis and were compared with the corresponding 22 segments from the 11 normals. Mean systolic septal thickening increased in the 22 segments of normals from 56 ± 3% (SEM) at rest to 77 ± 7% in exercise (p lt; 0.01) while in the patients' 22 wall segments supplied by stenotic vessels the mean value fell during peak exercise from 59 6 to 35 ± 3% (p lt; 0.005). Mean systolic posterior left ventricular wall thickening rose similarly in normals from 89 ± 9 to 115 ± 8% (p lt; 0.005) but fell during peak exercise from 75 ± 9 to 54 ± 9% (p lt; 0.01) in the patients' nine abnormally perfused segments. Maximal velocity of diastolic wall thinning rose from rest to exercise in the septa and posterior left ventricular walls of normals from 5.5 ± 0.3 to 7.7 ± 0.6 cm/sec (p lt; 0.005) and from 8.4 ± 0.8 to 11.8 ± 1.2 cm/sec (p lt; 0.001), respectively. In patients, these same indices fell at peak exercise from 5.9 ± 0.5 to 4.3 ± 0.4 cm/sec (p lt; 0.05) and from 8.3 ± 1.2 to 6.2 ± 1.4 cm/sec (p lt; 0.005 vs normals in exercise), respectively. The percent systolic change in left ventricular internal diameter increased from rest to exercise in normals from 38 ± 2 to 44 ± 2% (p lt; 0.001), but fell in patients during peak exercise from 35 ± 2 to 28 ± 2% (p lt; 0.001).Exercise echocardiography appears in these patients to be sensitive in detecting wall motion abnormalities during exercise-induced ischemia, and may be applicable in patients in whom exercise electrocardiography is equivocal, or where the functional significance of a coronary arterial lesion is uncertain.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

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 radionticlide angiocardiography was used before and during maximal upright bicycle stress in patients with nonsignificantly stenosed coronary arteries, and in those with > 75% stenosis. Gamma camera acquisitions were made in the 30° 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 lt; 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 lt; 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.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID

摘要:

Changes in myocardial perfusion and left ventricular function were evaluated pre- and postoperatively (3-6 months) in 14 patients with unstable angina who underwent coronary artery bypass surgery. Perfusion was studied with intracoronary and intragraft injections of radiolabeled macroaggregated albumin particles. Of 20 abnormal perfusion areas identified preoperatively, 13 demonstrated improved perfusion postoperatively. Segmental analysis of the left ventriculogram demonstrated improved wall motion in 29 abnormally contracting segments; 18 normalized. Areas which showed improvement of left ventricular perfusion were invariably associated with improvement of left ventricular wall motion. Five patients showed improvement in perfusion and contraction in areas of apparent old myocardial infarction.Thirteen of the 14 patients had significantly less angina whether or not there was evidence of improved perfusion. However, only those patients who demonstrated improved perfusion had a significant improvement in their treadmill exercise tolerance postoperatively. Thus, patients with unstable angina have perfusion defects which may be reversed as a result of saphenous vein graft surgery. Reversal of these perfusion abnormalities results in improved left ventricular performance and better exercise tolerance postoperatively.

ISSN:0009-7322    

出版商:OVID    

年代:1979

数据来源: OVID