Vereinfachte quantitative Auswertung von Indikatorverdünnungskurven

Lupus cardiomyopathy: cardiac mechanics, hemodynamics, and coronary blood flow in uncomplicated systemic lupus erythematosus

Right and left heart pressures, left ventricular volumes, indices of contractility, myocardial wall stiffness, and coronary blood flow were determined in five young women with systemic lupus erythematosus (SLE) during diagnostic right and left heart catheterization. Examinations revealed (1) increases of right and left ventricular enddiastolic pressures; (2) decreases of cardiac output, stroke volume, ejection fraction, contractility indices, diastolic left ventricular volume inflow; (3) decreases of pharmacologically induced coronary vasodilation in SLE. The results demonstrate impaired pump function, reduced contractility, increased myocardial wall stiffness, and decreased coronary vascular reserve in SLE. It is concluded that lupus cardiomyopathy associated with an impairment of left ventricular function may be apparent in young women with SLE who have no clinical signs of cardiac dysfunction.

Experimental hypothyroidism: depression of myocardial contractile function and hemodynamics and their reversibility by substitution with thyroid hormones

Hemodynamics and myocardial muscle mechanics have been studied in 22 euthyroid and 60 hypothyroid cats in which experimental hypothyroidism has been produced by thyroidectomy 61 days prior to the examination. Left ventricular to body weight ratio was altered due to a decrease in left ventricular weight and an increase in body weight. Heart rate, cardiac output and cardiac index were decreased (by 12-15 per cent), whereas stroke volume remained unchanges. Peak systolic pressure of the left ventricle was moderately decreased, the other pressures were in the normal range. There was a marked and significant reduction of isovolumic contractility indices indicating a depression of myocardial contractility in situ by 20-27 per cent. The isolated ventricular myocardium exhibited decreases of isotonic muscle shortening, of maximum isometric tension development and of the rates of both, isotonic shortening and isometric tension development by 12-35 per cent. Force-velocity relationships of contraction and relaxation were depressed to lower values of contraction and relaxation velocity as well as of maximum isometric muscle tension. The alterations in myocardial muscle mechanics and hemodynamics were completely reversible following substitution of the hypothyroid group with physiological doses of L-thyroxine (5 mug/kg/day for 8-18 days). Excess increases of parameters of myocardial performance were found following substitution of the hypothyroid group with L-thyroxine (500 mug/kg/day) in accordance with the induction of experimental hyperthyroidism in these animals. The results demonstrate impaired myocardial contractility and hemodynamics in experimental hypothyroidism. These changes are completely reversible by substitution with L-thyroxine in accordance with a reversible thyroid cardiomyopathy. The cellular mechanisms responsible for the altered cardiac activity in experimental hypothyroidism are discussed.

[Determination of cardiac output by means of an automatized thermal dilution technique (author's transl)]

Cardiac output was measured in 55 patients by the direct Fick method and an automatized thermodilution method. The results showed a good correlation (correlation factor r = 0.87, regression equation y = 0.91 x + 0.59). For the thermodilution method ice-cold normal saline solution as indicator substance was injected into the right atrium. The temperature-time-curve was measured by a thermistor located in the pulmonary artery. The area of indicator dilution was determined by electronic integration, the calculated cardiac output appeared as 1/min in digital display.

[Hemodynamics, left ventricular volumes and compliance in 167 patients with congenital and acquired heart disease (author's transl)]

In 167 patients with congenital and acquired heart disease (ventricular septum defect (VSD), atrial septum defect (ASD), mitral stenosis (MS), mitral insufficiency (MI), combined mitral stenosis and insufficiency (MV) aortic stenosis (AS), aortic insufficiency (AI), combined aortic stenosis and insufficiency (AV), idiopathic hypertrophic subaortic stenosis (HOK) hemodynamic measures (arterial pressure, right and left heart pressures, cardiac output, cardiac index, stroke volume, cardiac work), left ventricular volumes (endiastolic volume, endsystolic volume, ejection fraction, regurgitant flow) and diastolic pressure-volume relationships (on the basis of diastolic pressure-volume changes) were determined during routine right and left heart catheterization and left ventriculography. 1...

Experimental hyperthyroidism I. Hemodynamics and contractility in situ

The influence of experimental hyperthyroidism (intraperitoneal injection of crystalline L-thyroxine 1 mg/kg/day, 8-18 days) on cardiac mechanics in contractility in situ were studied in 30 hyperthyroid cats and compared with an euthyroid control group (n equals 30). 1. In hyperthyroidism left ventricular weight was considerably increased. Hypertrophy in hyperthyroidism represents a special case of myocardial hypertrophy, associated with an increase of myocardial performance. 2. Heart rate, systolic pressure, cardiac index, external cardiac work and tension time index were increased by 60-180 per cent. 3. Indices of contractility (dp/dtmax, t-dp/dtmax, dp/dtmax/IP) as well as isovolumetric force velocity relationships and VCE-max and Vmax demonstrated a considerable increase of contractility. Maximum rate isovolumetric pressure fall was increased by 120 per cent. Experimental hyperthyroidism is characterized by hypercirculation associated with increases of pressure, volume and velocity factors. The results are discussed with regards to the effects of increased cardiac mechanics on myocardial energy balance.