Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Electrocardiographic patterns of left axis deviation and left anterior hemiblock, defined by a frontal plane QRS axis of minus 30 degrees to minus 44 degrees and minus 45 degrees to minus 90 degrees, respectively, with normal QRS duration, were found to be fairly common (2.6 and 1.5 percent, respectively) in a community population of 8,000 Japanese-American men aged 45 to 69 years. More than 60 percent of men with these electrocardiographic patterns had no other cardiovascular abnormalities, and the incidence of fatal or nonfatal coronary heart disease and stroke in this group during observation periods of 3 to 6 years was not significantly different from that of control normal men. A significant association was found between these electrocardiographic patterns and the prevalence of hypertension, myocardial infarction and stroke. However, the association of myocardial infarction with left anterior hemiblock appeared to be coincidental and was attributed largely to the similarity of the electrocardiographic manifestations of left anterior hemiblock and inferior wall myocardial infarction. Men with left axis deviation were fatter and had higher blood pressure than the control population. No such difference could be demonstrated for men with left anterior hemiblock although this group was significantly older than control subjects and men with left axis deviation. The results of our study suggest that there are qualitative differences between the causative mechanisms and clinical features of left axis deviation and those of left anterior hemiblock.
Am J Cardiol 1975 Jun
PMID:Left axis deviation and left anterior hemiblock among 8,000 Japanese-American men. 113 Feb 90

Theoretical grounds are outlined for assessing the pump action of the heart and myocardial mechanics, respectively, in terms of ACG displacement ventricular function curve and displacement percentage amplitude-rate of ascent curve. These displacement relationship curves compare the a% of the ACG with the ACG-derived stroke volume, on the one hand, and the isovolumetric percentage amplitudes with the rate of ascent of the slope, on the other. They indicate the expected direction changes in the ventricular function and in the force-velocity relation curves.
Bibl Cardiol 1975
PMID:Evaluation of cardiac pump performance and heart muscle mechanics from the apex cardiogramm. Theoretical considerations. 113 Nov 67

A study of patients with patent ductus arteriosus and atrium septum defect, by use ofdirect body Bcg showed that an increased IJ amplitude is due to an increased stroke volume of the left and not of the right ventricle. High IJ amplitude is observed in patients with cardiovascular diseases, causing an increased output of the left ventricle ofover 50% above normal.
Bibl Cardiol 1975
PMID:Use of ballistocardiography for determining the hyperfunction of the left ventricle. 113 Nov 70

Seven patients with coronary heart disease (CHD) but no angina pectoris had hemodynamic studies at rest and during submaximal and maximal exercise levels 2 mth after an acute uncomplicated myocardial infarction. The hemodynamic study was repeated after 3 mth of regular physical training. Maximal oxygen intake (VO2max) increased by 16.1% after physical training while maximal heart rate unsignificantly decreased (minus 3.3%). Higher VO2max after training resulted from an increase in maximal cardiac output (+7%) and stroke volume (+9.2%) and from a widening of the maximal arterio-venous oxygen (A-VO2) difference (+7.3%). The fall in stroke volume observed from submaximal to maximal exercise level was not affected by training. During submaximal exercise, the lower heart rate after training was attended by both a greater stroke volume and a wider A-VO2 difference; the cardiac output slightly decreased. We conclude that the increase in VO2max observed with early physical training in CHD results on one hand from an increased stroke volume whose specificity is not established, and on the other hand from a wider maximal A-VO2 difference; the latter is entirely due to a greater extraction of oxygen from the blood by the working muscles during maximal exercise.
Eur J Cardiol 1975 Jan
PMID:Early hemodynamic adaptations to physical training in patients with healed myocardial infarction. 114 68

Beta adrenergic blockade has been suggested to improve the myocardial oxygen balance during ischemic conditions. This investigation was undertaken to examine the effects of practolol, a relatively cardiospecific beta adrenergic blocking agent, on regional myocardial dimensions and shortening during acute coronary arterial occlusion in dogs. Local myocardial dimensions were measured ultrasonically in ischemic and nonischemic regions of the left ventricle. Myocardial dilatation and marked reduction in systolic shortening occurred in ischemic regions after occlusion, whereas nonischemic regions were only moderately dilated. Administration of 10 to 20 mg of practolol exerted different effects in the two ventricular regions; myocardial dilatation was reduced and the systolic shortening increased by practolol in ischemic regions, whereas further dilatation and diminished shortening occurred in nonischemic control regions. Similar results were obtained when heart rate was kept constant by atrial pacing during beta adrenergic blockade. Thus, practolol improved the function in ischemic ventricular regions, and restored ventricular stroke volume to preocclusion levels, probably as a result of improved myocardial oxygen balance.
Am J Cardiol 1975 Aug
PMID:Effect of practolol on left ventricular dimensions during coronary occlusion. 115 39

To study the efficacy of isosorbide dinitrate in prevention of myocardial ischemia, 20 patients with angiographically proved coronary artery disease underwent atrial pacing (mean rate 138/min) before (P1), 10 minutes after (P2) and 65 minutes after (P3) sublingual administration of 5 mg of isosorbide dinitrate. The symptomatic, hemodynamic and metabolic responses were evaluated at rest and during each pacing period. Angina occurred in all subjects during P1. Angina did not recur or was less severe in 17 of 19 patients during P2 and in 19 of 20 patients during P3. Resting left ventricular end-diastolic pressure for the group was normal at 11 plus or minus 4 mm Hg (mean plus or minus standard deviation). On interruption of pacing at 4.5 minutes during P1, average end-diastolic pressure during sinus rhythm was abnormal (18 plus or minus 6 mm Hg). After administration of isosorbide dinitrate mean left ventricular end-diastolic pressure was significantly decreased at rest and remained normal when pacing was interrupted during P2 and P3. Brachial arterial pressure, cardiac index, tension-time index, left ventricular stroke work index and maximal rate of rise of left ventricular pressure were all diminished at rest before and during P2 and P3. S-T segment depression was less during P2 and P3 than during P1. Before isosorbide dinitrate was given, resting myocardial lactate extraction was 15 plus or minus 11 percent during P1 lactate extraction decreased to minus2 plus or minus 25 percent. Lactate extraction was significantly greater during P2 and P3 than during P1. This study demonstrates that sublingual administration of 5 mg of isosorbide dinitrate has a significant protective effect against pacing-induced myocardial ischemia at 10 and 65 minutes after administration.
Am J Cardiol 1975 Aug
PMID:Effects of isosorbide dinitrate on the response to atrial pacing in coronary heart disease. 115 42

Left ventricular function and motion in 12 adults with an ostium secundum atrial septal defect were analyzed utilizing biplane cineangiography. Values for left ventricular end-diastolic volume index, stroke volume index, ejection fraction, left ventricular end-diastolic pressure and mean rate of circumferential fiber shortening were compared with values in an age-matched group of 11 normal subjects. Comparisons of ventriculographic and echocardiographic data were also made in 5 patients and 10 control subjects. Cardiac index was smaller in patients than in the normal subjects (3.6 vs. 4.5 liters/min per m2, P less than 0.01). Although left ventricular end-diastolic pressure was similar (8 mm Hg in both groups), the end-diastolic volume index was significantly smaller in patients than in normal subjects (56 vs. 76 ml/m2, P less than 0.05). Stroke volume index was also significantly smaller in patients (40 vs. 52 ml/m2, P less than 0.01). The two groups had similar values for ejection fraction (65 +/- 2 percent [standard error of the mean] in patients vs. 68 +/- 2 percent in normal subjects), circumferential fiber shortening velocity (1.67 +/- 0.13 vs. 1.81 +/- 0.15 circumferences/sec.), heart rate (91 +/- 7 vs. 90 +/- 5 beats/min) and mean systemic arterial pressure (92 +/- 5 vs. 87 +/- 3 mm Hg). Early systolic bulging of the upper ventricular septum toward the right ventricle was seen in 10 of 12 patients with an atrial septal defect but in no normal subject. Echocardiographic data supported these findings. No other abnormalities of motion were consistently noted. It is concluded that the left ventricle of patients with an atrial septal defect is subnormal in volume and abnormal in sequence of contraction of the septum and is characterized by apparent decreased distensibility.
Am J Cardiol 1975 Sep
PMID:Abnormalities of left ventricular function and geometry in adults with an atrial septal defect. Ventriculographic, hemodynamic and echocardiographic studies. 116 35

Pulsecontour methods remain a potentially attractive approach for the calculation of stroke volume, since they might provide such information on a beat to beat basis, after a single calibration. In order to test the clinical value of this hypothesis stroke volume estimates from six different pulsecontour formulae were compared with stroke volume values obtained with an electromagnetic flowmeter in 10 pigs. Each of the formulae failed to confirm its usefulness under circumstances mimicking clinical conditions. The calibration constant obtained during control states varied widely (+/- 25%). In many instances polsecontour formulae predicted changes in stroke volume in a direction opposite from those measured. The need for recalibration was so frequent that the calibration merthod itself proved often sufficiently informative. It is concluded that in intensive care units pulsecontour formulae cannot contribute to the care of the patient. Its popularity is not justified and its increased use since the introduction of computers is not warranted.
Basic Res Cardiol
PMID:Stroke volume from central aortic pressure? A critical assessment of the various formulae as to their clinical value. 119 Dec 6

The cardiac dynamic consequences were evaluated of constant infusions of dobutamine and isoproterenol at graded dose levels into conscious, healthy instrumented dogs. Measurements were made of simultaneous changes in left ventricular internal diameter, pressure, aortic pressure and rate of rise of left ventricular pressure(dP/dt), as well as the left ventricular electrogram. From these primary variables, derived variables were computed using programs in a minicomputer system. The data showed that, with increasing doses of dobutamine there were significant linear increases in all measured indexes of myocardial contractility, such as the rate of rise of left ventricular pressure at a developed isovolumic pressure of 40 mm Hg (dP/dt/P40), mean velocity of left ventricular fiber shortening, ejection fraction and stroke work. These changes in myocardial contractility occurred without changes in end-diastolic volume, mean aortic pressure or heart rate when dobutamine was infused in doses of 5 to 20 mug/kg per min. Isoproterenol also produced linear changes in indexes of myocardial contractility but in doses of 0.02 to 0.10 mug/kg per min, it produced a significantly higher heart rate at any given level of contractility than that produced by dobutamine. Cardiac minute work (heart rate X stroke work) was increased by both drugs. However, with infusions of isoproterenol the amount of cardiac minute work was significantly limited because of the changes in heart rate, whereas with dobutamine cardiac minute work could be increased to a higher level as a function of changes in myocardial contractility alone without changes in heart rate. These data suggest that dobutamine selectively increases myocardial contractility.
Am J Cardiol 1975 Dec
PMID:Comparative cardiac dynamic effects of dobutamine and isoproterenol in conscious instrumented dogs. 119 45

The left ventricular performance in patients with mitral stenosis has been assessed by echocardiography, through the measurement of various parameters, such as the stroke volume, the ejection fraction (EF), the mean circumferential fiber shortening rate (VCF), the cardiac work and the left ventricular mass. Among these parameters only EF and VCF are statistically lowered in mitral disease, in comparison with their value for normal hearts: the mean value of EF is 0.62 in healthy people and 0.49 in mitralic patients; the mean value of the VCF rate is 1.05 circ/s and 0.78 circ/s respectively. The cardiac work and power in the considered patients are on the average lower than normal values by about 10%, but not significantly so. A good correlation has been obtained between the left ventricular work and mass, whereas no correlation has been found between the ventricular wall thickness and the diameter of the left cavity, both measured at end-diastole. The quotient of the ventricular thickness and intracavity radius, in diastole, is equal to 0.38 in healthy people and 0.30 in mitralic patients. Lastly, the echocardiographic results and those of angiocardiographic literature were in agreement.
G Ital Cardiol 1975
PMID:[The contractile function of the left ventricle in pure mitral stenosis. Echocardiographic analysis]. 120 43


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>