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At least 19 recordsLinked to original sources
PubMed1977

Effect of sodium bicarbonate on canine left ventricular function.

Left ventricular performance was evaluated in seven canine right heart bypass preparations during and after the intraauricular administration of sodium bicarbonate (100 ml, 1100 Osm, 60 mEq). Under conditions of constant cardiac input and left ventricular volume, sodium bicarbonate produced mild and brief left ventricular depression, as manifested by a decline of left ventricular dp/dt with simultaneous rise of left ventricular end-diastrolic and left atrial pressures. These findings occurred as aortic impedance fell. Identical results accrued in paced and unpaced preparations. The data lends credence to the proposition that a sudden rise in blood pCO2 produces increased transport of CO2 across the cardiac membranes with intracellular acidosis. However, the data is also compatible with hyperosmolality induced contractile depression. Possible clinical implications are discussed.

Animals↗
PubMed1977

Left ventricular endomyocardial biopsy. III: ultrastructural characteristics of cardiomyopathy and cardiac hypertrophy with good or poor ventricular function.

Left ventricular endomyocardial biopsies have been obtained from patients with cardiomyopathy and hypertrophy due to aortic valve disease. These biopsies have been examined by electron microscopy and the ultrastructural abnormalities compared. In congestive cardiomyopathy no specific abnormalities were found although myofibrillary degeneration and membrane-bound vacuoles were more commonly present. Crossing of whole groups of sarcomeres was found only in asymmetric septal hypertrophy, but was not present in all cases. Amyloid deposits were demonstrated easily by electron microscopy in patients with restrictive cardiomyopathy. In the patients with hypertrophy due to aortic valve disease, no specific features were found and ultrastructural abnormalities did not differentiate between normal and impaired left ventricular functions.

Aortic Stenosis, Subvalvular↗
PubMedDate not supplied

[Left ventricular function in chronic obstructive lung disease (author's transl)].

Left ventricular function was studied at rest and during post-extrasystolic potentiation in 18 patients with chronic obstructive lung disease. The contractility indices used were obtained from pressures recorded in the isovolumetric period (left ventricular end-diastolic pressure, Vmax., VECmax., dP/dtmax.) and from volume variations during ejection (end-diastolic volume, ejection fraction, VCF). Left ventricular diastolic compliance was also evaluated. All patients were hypoxic (PaO2 = 58 +/- 7 torr); six of them had cor pulmonale (group B); the remaining 12 patients constituted group A. Left ventricular function of groups A and B was similar; we conclude that right cardiac failure, in cor pulmonale, is not secondary to left ventricular failure. However, left ventricular dysfunction exists; the left ventricle is hypertrophied (probably resulting from chronic hypoxia). Pump function is altered (abnormal ventricular function points are found), but left ventricular kinetics is normal or exaggerated (ejection fraction and VCF are increased). Isovolumetric phase contractility indices are diminished; however, they may increase normally during post-extrasystolic potentiation. Left ventricular compliance is abnormal due to left and right ventricular hypertrophy and to paradoxical movement of the interventricular septum which impedes diastolic expansion of the left ventricle. These changes are responsible for decreased left ventricular output. There seems to exist an impairment of left ventricular function related to both intrinsic (secondary to hypoxia, hypercapnia, left ventricular hypertrophy) and extrinsic factors (right ventricula hypertrophy deviating interventricular septum, lowering of left ventricular preload).

Adult↗
PubMed1978

[Left ventricular function in hypertension treated with beta blockers].

In 14 patients with essential hypertension, left ventricular function was assessed echocardiographically before and after 4 and 8 weeks of treatment with the betablocking agent atenolol. Atenolol was given orally in a dose of 100 mg/day. After 4 weeks of treatment systolic blood pressure decreased from 160 to 138 mm Hg(p less than 0.001) and diastolic pressure from 105 to 91 mm Hg(p less than 0.001). Heart rate decreased from 76 to 64 beats/min (p less than 0.05). Systolic shortening of the left ventricular transverse diameter declined from 41 to 36% (p less than 0.01), though in no instance did it fall below the lower limit of normality (30%). After 8 weeks of betablocking therapy, blood pressure and heart rate remained essentially unchanged. Systolic shortening increased slightly but insignificantly to 38%. The left ventricular enddiastolic diameter did not change throughout the study. It is concluded that longterm betablocking therapy is associated with a significant reduction of left ventricular function which improves in the later stage of treatment. Since the diminution of left ventricular function is slight, the induction of left heart decompensation is unlikely, at any rate in patients with initially normal left ventricular function.

Adrenergic beta-Antagonists↗
PubMed1978

Left ventricular function in exercise-induced hypertrophy in dogs.

Indexes of left ventricular function and diastolic compliance were studied in 10 awake exercise-trained greyhounds with left ventricular hypertrophy. Mean left ventricular to body weight ratio and mean myocardial cell diameter were significantly greater than in normal dogs (8.73 +/- 2.7 [standard error of the mean] versus 4.63 +/- 0.24 g/kg, P less than 0.01; and 18.3 +/- 0.67 versus 12.5 +/- 0.71 mu, P less than 0.01, respectively). In awake resting animals, 7 to 50 days after implantation of a high fidelity micromanometer and sonomicrometer crystals, left ventricular contractility indexes were similar to those measured previously in normal dogs (maximal derivative of left ventricular pressure [dP/dt] 3,800 +/- 250 versus 3,810 +/- 330 mm Hg/sec, difference not significant; and mean rate of circumferential fiber shortening 1.54 +/- 0.12 versus 1.43 +/- 0.12 sec-1, difference not significant). During volume loading sufficient to produce a left ventricular end-diastolic pressure of 20 mm Hg, changes in contractility indexes were similar to those in normal dogs; however, heart rate increased significantly (74 percent, P less than 0.005) in the trained greyhounds but not in normal dogs. Left ventricular diastolic stiffness did not differ from normal (51.6 +/- 3.0 versus 45.9 +/- 5.9 mm Hg/cm, P less than 0.01). These findings suggest that left ventricular function in exercise-induced left ventricular hypertrophy is substantially normal.

Animals↗
PubMed1979

Influence of preoperative left ventricular function on results of homograft replacement of the aortic valve for aortic stenosis.

The effect of preoperative left ventricular function on early and late prognosis was assessed in 103 patients with aortic stenosis who underwent left ventricular cineangiography before homograft replacement of the aortic valve. The patients were separated into two groups: Group A (58 patients) with an ejection fraction of 0.46 or more and Group B (45 patients) with an ejection fraction of 0.45 or less. The two groups were compared with respect to clinical and hemodynamic data as well as operative result. There was poor correlation between clinical data and left ventricular function. In Group A there were three early deaths (5.2 percent) and three late deaths (5.2 percent) compared with no early and six late deaths (13.3 percent) in Group B during the follow-up period of 12 to 102 months (mean 43 months). Most patients in Group B showed considerable symptomatic improvement but less than that observed in Group A. Forty-two patients (13 in Group A and 29 in Group B) underwent repeat cardiac catheterization and coronary angiography. Improvement in left ventricular function as assessed by radial analysis of segmental wall motion and ejection fraction was observed in 20 of the 29 patients in Group B. Failure of left ventricular function to improve was associated with additional coronary artery disease in the majority of patients. It is concluded that poor left ventricular function does not increase the risk of aortic valve replacement for aortic stenosis and that improvement in left ventricular function can be expected in the majority of patients.

Adolescent↗
PubMed1979

Assessment of left-to-right shunt and left ventricular function in isolated ventricular septal defect. Echocardiographic study.

This echocardiographic study was designed to assess left ventricular function and pulmonary blood flow in ventricular septal defect. Fifty-one patients aged 2 weeks to 21 years were investigated (group 2). Five of 10 operated patients were studied one week after surgical closure of the defect (group 3) and seven 3 to 6 weeks postoperatively (group 4). The control group consisted of 45 normal subjects aged 2 weeks to 21 (group 1). Left atrium/aortic root dimension ratio (LA/Ao) was used to express the pulmonary systemic flow ratio. Left ventricular chamber size was assessed by measurement of left ventricular end-diastolic dimension and volume. The left ventricular mass and the ratio of end-diastolic volume to left ventricular mass were determined to relate the degree of left ventricular hypertrophy to volume overload. Myocardial function was evaluated using ejection phase indices. Ventricular septal thickness, posterior wall thickness, and echocardiographic patterns of septal motion were also studied. The left atrium/aortic root dimension, end-diastolic volume, and left ventricular mass were significantly greater in group 2 patients (P less than 0.05) than in the normal controls. There was a very good correlation between LA/Ao and pulmonary/systemic flow ratio (r = 0.83). Eleven of the group 2 patients showed asymmetric septal hypertrophy (unrelated to shunt size) but left ventricular function as assessed by ejection phase indices appeared unimpaired. Immediately after operation (group 3) there was a deterioration in left ventricular function in 5 patients as shown by reduced ejection fraction, mean velocity of circumferential shortening, and relative changes in minor axis with systole. Septal motion was impaired but returned to normal in 3 to 6 weeks in 7 patients (group 4). Left atrial/aortic root dimension, end-diastolic volume, and left ventricular mass decreased significantly immediately after operation (group 3) but were still raised at 3 to 6 weeks (group 4).

Adolescent↗
PubMed1977

The evaluation of left ventricular function by echocardiography.

Echocardiographic assessment of left ventricular size and function correlates well with that made by cineangiography. The technic is particularly suited to the early detection and serial monitoring of left ventricular hypertrophy and dysfunction in valvular heart disease, hypertensive heart disease and the cardiomyopathies. It also has advantages over angiography in experimental situations in which frequently repeated or continuous assessment of left ventricular size and function may be required. The limited usefulness of a single ultrasound beam in segmental heart disease, such as ischemic heart disease, may be overcome in the future with improvements in two-dimensional echocardiographic technics.

Cardiac Output↗
PubMed1978

Dynamic ventriculography in patients with ischaemic heart disease. II. Influence of postextrasystolic potentiation on left ventricular function.

The effect of postextrasystolic potentiation [PESP] on left ventricular [LV] function was assessed by means of left ventricular cineangiography in 26 patients with ischaemic heart disease. Ventricular extrasystoles were induced by a catheter inserted into the LV during injection of the contrast agent. The values of parameters of segmental and global function of LV, found in potentiated and nonpotentiated sinus contractions, were compared. Segmental disturbances present at rest in 13 patients improved or disappeared after extrasystole in 8 patients. Improvements in contraction also took place in segments with normal resting contraction. Global LV function improved significantly; an improvement was observed even without an increase in the LV end-diastolic volume in the postextrasystolic beat. The advantages and limitations of the method for preoperative estimation of the effect of intended myocardial revascularization on the LV function are discussed.

Adult↗
PubMed1977

Interventricular septal motion and left ventricular function after coronary bypass surgery: evaluation with echocardiography and radionuclide angiography.

To evaluate interventricular septal motion and left ventricular function after coronary bypass graft surgery, 40 patients were studied early postoperatively and serially for up to 16 months with echocardiography and radionuclide angiography. Early after operation mean left septal excursion decreased significantly from 4.6 +/- 0.4 (standard error) to 0.8 +/- 0.6 mm (P less than 0.001), and left septal motion was abnormal in 23 of the 40 patients. Mean right septal excursion reversed from 2.1 +/- 0.5 to -2.1 +/- 0.5 mm early after operation in the 22 patients in whom these measurements could be made, and 15 patients showed paradoxical right septal excursion. At a mean of 4 months after operation, only 7 of 35 patients followed up had abnormal left septal motion, and mean left septal excursion had returned toward normal (3.6 +/- 0.7 mm); mean right septal excursion remained reversed (--1.1 +/- 0.7 mm), and 6 of the 14 patients followed up had paradoxical motion. In the 22 patients whose wall thickness could be measured, mean septal thickening during systole decreased significantly from 35 +/- 4 to 21 +/- 3 percent early after operation (P less than 0.01). During late follow-up septal thickening returned toward normal (32 +/- 4 percent). Mean normalized posterior wall velocity increased significantly after operation from 0.76 +/- 0.03 to 1.01 +/- 0.05 sec-1 (P less than 0.001), but posterior wall thickening remained unchanged. Left ventricular end-diastolic dimension and the radionuclide-determined left ventricular ejection fraction were unchanged postoperatively. It is concluded that (1) echocardiographically detected abnormal septal movement is frequent early after coronary bypass graft operation; (2) both decreased myocardial contraction in the septum and increased anterior movement of the whole heart contribute to this abnormality; (3) the abnormalities in septal movement decrease during late follow-up in many patients but persist in some patients; and (4) posterior wall function tends to increase early after operation and therefore overall left ventricular function remains normal.

Adult↗
PubMed1978

Dynamic ventriculography in patients with ischaemic heart disease. I. Influence of nitroglycerin on left ventricular function.

In 25 patients with ischaemic heart disease the effect of nitroglycerin [NTG] on segmental and global function of the left ventricle was assessed by means of left ventricular cineangiography. In 14 patients a segmental disturbance of contraction at rest was found; in six of them the function inproved after NTG. After NTG, the left ventricular diastolic volume, end-diastolic pressure, and systolic blood pressure decreased, the heart rate increased. The global left ventricular function did not significantly change. In patients with ischaemic heart disease NTG helps to differentiate reversible and irreversible disturbances of left ventricular contraction.

Adult↗
PubMed1979

Left ventricular function at rest and during exercise after aortic valve replacement in patients with aortic regurgitation.

To determine the effect of aortic valve replacement on reversing abnormalities of left ventricular function in patients with aortic regurgitation, radionuclide cineangiography was used to study 16 sympatomatic patients with aortic regurgitation before and 6 months after aortic valve replacement. Before operation, left ventricular ejection fraction was 46 +/- 3 percent at rest (normal mean +/- standard error of the mean 57 +/- 1 percent; P less than 0.001), and decreased to 37 +/- 4 percent during exercise (normal 71 +/- 2 percent; P less than 0.001). after operation, ejection fraction rose to 58 +/- 4 percent at rest, indistinguishable from the normal value, and during exercise was 53 +/- 4 percent, increased (P less than 0.001) from before operation but significantly (P less than 0.001) subnormal. Thus, aortic valve replacement can improve but usually does not normalize left ventricular function during exercise in symptomatic patients with aortic regurgitation.

Adult↗
PubMed1975

[Effect of increasing doses of dopamine on the left ventricular function in the dog].

A study on eleven dogs of the effects of increasing doses of dopamine on the left ventricular function. A description of the method which consists of a venous shunt connected to an extra-corporeal circuit and which allows modification simply and rapidly of the state of vascular refilling of the animal. The results differ according to the pressure-level of the refilling of the left ventricule. At low pressure, the dopamine increases the arterial pressure, the cardiac output and the systolic activity of the left ventricle for a reduced tachycardic effect. At higher pressure, the average aortic pressure is only slightly increased and the systolic activity is elevated without increase in cardiac output. These facts indicate dopamine in states of shock with a low pressure of refilling.

Animals↗
PubMed1978

Left ventricular function in beta-thalassemia and the effect of multiple transfusions.

Left ventricular performance was studied in 23 young patients with severe chronic anemia due to beta-thalassemia major and intermedia. The patients were divided into three groups according to the number of blood transfusions they had received. The left ventricle (LV) was enlarged in patients who had not received blood and larger still in patients who had received multiple transfusions. Echocardiography and systolic time interval measurements showed that systolic function of the LV was good in all the patients and that there was no statistical difference in systolic function in patients who had and those who had not received multiple transfusions. Heart rate was increased in the latter group. Stroke index and cardiac index were high, especially in patients in Group 3. The diastolic closure rate (EF slope) of the anterior mitral leaflet and its amplitude of movement were increased, but less so in Group 3; this may reflect an alteration in diastolic LV distensibility. The results indicate that despite the presence of cardiomegaly and severe clinical congestive heart failure, LV performance is well preserved in patients with beta-thalassemia, even in those who have received repeated blood transfusions. Clinical cardiac failure is the consequence of volume overload and abnormal chamber compliance. There was no evidence in this of a congestive cardiomyopathy.

Adolescent↗
PubMedDate not supplied

Left ventricular systolic wall stress as a primary determinant of myocardial oxygen consumption: comparative studies in patients with normal left ventricular function, with pressure and volume overload and with coronary heart disease.

Left ventricular dynamics, coronary blood flow (Vcor), and myocardial oxygen consumption (MVO2) were determined in normal patients (N), in chronic pressure overload (aortic stenosis, AS), in chronic volume overload (aortic incompetence, AI), and in coronary heart disease (CHD). Peak systolic and enddiastolic wall stress were increased in AS and AI by 26-52 per cent, the systolic stress being preferably increased in AS, whereas enddiastolic stress was markedly greater in AI. Vcor and MVO2 were elevated in both groups by 45-55 per cent (p less than 0.001). Sufficient correlation was present between peak systolic wall stress and the MVO2 (r equal to 0.82). Since at a given wall stress the MVO2 was somewhat increased in AI and AS when compared with N and CHD, the considerable inhancement of the rate of pressure development (AS) was well as of the external cardiac work (AI) may contribute to the increase in overall oxygen consumption. It is concluded that systolic wall stress represents a primary determinant of MVO2 in pressure and volume overload and that the MVO2 increases in these diseases when hypertrophy becomes inappropriate with regard to the pressure and volume demands imposed to the left ventricle.

Aortic Valve Insufficiency↗
PubMed1979

Influence of post-extrasystolic potentiation on left ventricular function estimated by means of systolic time intervals.

Systolic time intervals were measured in 50 patients with frequent premature ventricular beats. The patients were divided into two groups: group I included those which showed in the beat that preceded an extrasystole a pre-ejection period/left ventricular ejection time (PEP/LVET) ratio greater than or equal to 0.43, and group II with PEP/LVET ratio greater than 0.44. Systolic time intervals recorded during post-extrasystolic potentiation were compared with those measured in the preextrasystolic complex. Also the measured intervals were tested against the hourly rate of premature beats obtained by electrocardiographic telemetric monitoring. The results confirmed the following results of previous reports: a) ventricular premature beats are followed by sinus-potentiated contractions inversely related to the coupling interval and dependent on adequate compensatory pauses; b) potentiated contractions are greater in patients with ventricular dysfunction. No relationship was found between left ventricular performance and the rate of premature beats. It is concluded that the effect of an antiarrhythmic intervention on the left ventricular function might be adequately evaluated by means of systolic time intervals and provoked post-extrasystolic potentiation, with the advantage of using totally non-invasive procedures.

Cardiac Complexes, Premature↗