Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Cardiac function”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed1979

Cardiac function in goats exposed to carbon monoxide.

To investigate the possibility that prolonged carbon monoxide (CO) exposure would depress myocardial function, six chronically instrumented, unsedated goats were exposed to 160--200 ppm CO for 2 wk, resulting in a mean carboxyhemoglobin saturation of 20%. Cardiac index and stroke volume remained unchanged during and after exposure. Hematocrit and hemoglobin concentration started increasing on the 10th day of exposure, this increase reached statistical significance (P less than 0.05) on the 6th postexposure day. Contractility (Vmax) of the left ventricular myocardium and heart rate were unchanged during exposure to CO, but both were significantly (P less than 0.05) decreased at some time during the 1st wk after removal from CO. If there was a decrease in intrinsic myocardial function during CO exposure, it may have been masked by increased sympathetic activity. The mechanism(s) that might produce the decrease in heart rate and contractility after removal from CO are not obvious. Possible explanations are discussed.

Animals↗
PubMed1979

[Index of isometric contraction--a comparison with invasive methods of cardiac function testing in patients with ischemic heart diseases and post-myocardial infarct status].

In 81 patients with an ischaemic heart disease and myocardial infarction the evidence of the presphygmic index PI (non-invasive index) was tested concerning a beginning myocardial functional disturbance and a latent heart insufficiency, respectively, with the help of an invasive cardiopulmonary functional diagnostics which was performed under dosed bicycle ergometer load in the steady state. The presphygmic index PI correlates in significantly positive way with the end-diastolic pressure of the heart and the quotient from minute volume of the heart and the end-diastolic pressure of the pulmonary arteries (VM/PAEDP). The presphygmic index is on the basis of this correlation of the left-ventricular function suitable to establish disturbances of the myocardial functions and to give the possibility of a separation of the patients in cardially sufficient and cardially insufficient ones. Here the evidence of the presphygmic index might be larger concerning the recognition of a latent heart insufficiency than concerning the recognition of beginning myocardial functional disturbances. The presphygmic index apparantly possesses a high degree of sensibility then, when the myocardial functional disturbances coincide with a beginning reduction of the pumping action of the heart.

Adult↗
PubMed1978

Cardiac function in the normal newborn: additional information by computer analysis of the M-mode echocardiogram.

Computer analysis of the M-mode echocardiogram in 50 normal newborns provided measurements of wall thicknesses and chamber size and, in addition, assessment of right and left ventricular wall, septal, and cavity dynamics throughout the cardiac cycle. Data obtained with this new technique indicated that (1) right and left ventricular cavity functions are similar in the normal newborn, (2) right and left ventricular cavity filling and emptying vary directly with peak rates of septal and ventricular wall thinning and thickening, respectively, and (3) there is a close time relationship among maximum left atrial dimension, minimum left ventricular dimension, and mitral valve opening. This analysis, which is the first complete analysis of the echocardiogram in the newborn, provides a normal range of septal and ventricular wall dynamics as well as right and left ventricular and left atrial function and has clinical implications in that it may allow early recognition of both congenital and perinatal myocardial disease.

Atrial Function↗
PubMed1976

Noninvasive measurement of cardiac function during exercise, using resaturation curves.

The resaturation curve, a noninvasive indicator-dilution test using an ear oximeter to detect rates of change in arterial oxygen saturation during breathing of various concentrations of oxygen, was used to assess cardiac performance in normal subjects and in 108 patients with cardiac valvular disease. Measurements made during exercise included the time constant of resaturation (tau) and beat-to-beat changes in arterial oxygen saturation (the left heart clearance fraction). At maximum rates of voluntary work, patients had a significantly reduced clearance fraction and longer tau than normal subjects. Clearance fraction and tau improved in patients after aortic valve replacement; deterioration occurred in tau and clearance fraction over time in patients treated medically, as compared to normal subjects who showed little change during a ten-year period. Clearance fraction and tau correlated with hemodynamic data obtained during cardiac catheterization. The resaturation curve provides an objective measure of cardiac impairment that can be readily repeated during follow-up of patients with heart disease.

Adult↗
PubMedDate not supplied

[Effect of lithium chloride on several indices of cardiac function].

Used in a dose of 100 mg/kg lithium chloride modifies the ECG patterns in rats, rabbits and cats. It increases the voltage of P and R waves, the S-T interval and slows down the rhythm of cardiac contractions. In doses of 50-300 mg/kg the compound raises the coronary circulation rate in narcotized cats. The compound exerts an antiarrhythmic action in chlorocalcium arrhythmia in rats, in strophanthin-induced one in cats and frogs and the intensity of this action is not inferior to that produced by potassium chloride, quinidine, novacainamide, izoptin and even exceeds it.

Animals↗
PubMed1978

Cardiac function at rest and during exercise in normals and in patients with coronary heart disease: evaluation by radionuclide angiocardiography.

This study demonstrates that radionuclide angiocardiography provides a simple and noninvasive approach for evaluation of myocardial function. Previous work concerning myocardial performance has been generally conducted with the patient in the supine position. Radionuclide angiocardiograms were performed in the present study at rest and during exercise in 30 normal subjects and in 30 patients with ischemic coronary artery disease. There were 30 normal controls (Group I), ten with single coronary artery disease (Group II), and 20 patients with multiple vessel coronary disease (Group III). All subjects were studied in the erect posture on a bicycle ergometer. In the normal controls, the mean heart rate doubled and the cardiac output tripled during exercise. Intensive training can lead to extraordinary levels of cardiac performance as shown in a world-class athlete who during peak exercise attained a heart rate of 210, an ejection fraction of 97%, and a cardiac output of 56 litres per minute. In the patients with coronary artery disease, both groups, were able to increase cardiac output to approximately twice the resting value. The magnitude of increase in blood pressure during exercise was not significantly different in the three groups. However, definite changes were present in the end-diastolic volume at rest was 116 and rose to 128 ml in Group I, 93 rising to 132 ml in Group II, and 138 increasing to 216 ml in Group III. The stroke volume increased comparably in all three groups, but the ejection fraction from rest to exercise showed a marked contrast in the controls compared to those with multivessel coronary disease. The ejection fraction rose in Group I from 66 to 80% during exercise, while in Group II it fell from 69 to 67%, and in Group III from 60 to 46%. These findings indicate that patients with ischemic myocardial disease respond to the stress of exercise by cardiac dilatation to maintain of increase stroke volume at increased heart rates. Moreover, the magnitude of this response appears to be greatest in patients with left main coronary artery stenosis. This approach for evaluating myocardial function during exercise provides useful data of importance in selecting medical versus surgical management of patients with ischemic coronary artery disease.

Adult↗
PubMed1978

Effects of nitroglycerin on cardiac function and regional blood flow distribution in conscious dogs.

The effects of intravenous infusion of nitroglycerin (NTG), 8 and 32 microgram/kg.min for 7 min, and of sublingual NTG, 1.2 mg, were examined on direct and continuous measurements of systemic, coronary, and regional hemodynamics, left ventricular (LV) dimensions, pressures, and myocardial contractility in conscious dogs. NTG induced sustained reductions in LV dimensions and transient increases in heart rate and dP/dt, and decreases in mean arterial pressure. Initially NTG increased cardiac output and flows to the coronary, mesenteric, renal, and iliac beds, while systemic and regional vascular resistances fell. Later, cardiac output, cardiac work, and mesenteric and iliac flows fell significantly below control, and significant vasoconstriction in the systemic as well as mesenteric, iliac, and coronary beds was observed at a time when LV end-diastolic dimensions were still significantly reduced. Peripheral vasoconstriction was not observed with systemic NTG in deafferented dogs or when NTG, 1 microgram/kg.min, was infused intra-arterially into the iliac bed. Thus, systemic NTG induces a biphasic response consisting of initial arteriolar vasodilation followed by vasoconstriction in the mesenteric, iliac, coronary and systemic beds, which is presumably due to longer lasting effects on preload and to secondary reflex responses to the drug.

Administration, Oral↗
PubMed1979

Modification of cardiac function by synchronized oscillating acceleration.

The sensitivity of selected cardiovascular (CV) responses to the physical stressor of External whole-body oscillating Acceleration Synchronized with the Electrocardiogram (EASE) was analyzed in 8 chronically instrumented tranquilized dogs. A sinusoidal acceleration wave form was imposed on the supine animals along the spinal (+/- Gz) axis at a constant amplitude of +/- 0.75 G, and a frequency equal to the paced-heart frequency (2--3 Hz). When the peak force was positive in early systole, and negative in early diastole, changes in myocardial oxygen consumption (MVo2, + 8%), mean coronary flow (MCF, + 8%), stroke volume (SV, + 15%), cardiac work (CW, + 19%) and the time derivative of left ventricular pressure (dP/dt, + 18%) were minimal in comparison to nonoscillatory control values. When the peak force was positive in early diastole and negative in late diastole and early systole, changes in MVo2 (+ 41%), MCF (+ 39%), SV (+ 33%), CW (+ 50%), and dP/dt (+ 31%) were maximal. Thus the capability of EASE to produce a range of desired sustained CV responses provides a basis for its potential diagnostic/therapeutic applications.

Acceleration↗
PubMed1978

Transfusion of 2,3 DPG-enriched red blood cells to improve cardiac function.

Attempts were made to enhance oxygen availability in patients undergoing coronary artery bypass operations by transfusing red blood cells enriched in 2,3 diphosphoglycerate (2,3 DPG) to 150% of normal. In this study of 22 patients, 11 received red blood cells with high 2,3 DPG levels and 11 received red blood cells with 70% of normal 2,3 DPG levels (control). Immediately following cardiopulmonary bypass the 11 patients who received high 2,3 DPG red blood cells had a P50 value of 31.6 mm Hg; the value in control patients was 28.3 mm Hg (p less than 0.05). Oxygen consumption values were 135 and 106 ml/min/m2, respectively (p less than 0.05). Mixed venous oxygen tensions were similar in the two groups, but the arteriovenous content difference was higher in the high 2,3 DPG group (p less than 0.05). Cardiac indices increased significantly in response to a fluid load in the high 2,3 DPG group compared with controls at comparable filling pressures. We believe the improved myocardial performance in response to a fluid challenge is a result of increased oxygen availability.

Blood Transfusion↗