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 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hemodynamic factors measured at cardiac catheterization in 40 infants and children with chronic endomyocardial disease were analyzed in regard to subsequent clinical condition. The patients were followed for periods ranging from 2 months to 11 years (average 4.3 years) after initial cardiac catheterization. There were no statistically significant differences in left ventricular end-diastolic volume among survivors with no symptoms, survivors with persistent congestive heart failure, and nonsurvivors. Ejection fractions were depressed in about four fifths of patients with chronic endomyocardial disease and were significantly lower in the group of patients who died subsequently. LVEDP in patients who did not survive was significantly higher than in asymptomatic survivors, but there was too much overlapping of individual values to be of prognostic value. Left ventricular pressure-volume loops appeared to offer an improved, although more tedious, method of assessing LV function. In addition to offering information on LVEDV, LVEDP, and EjF, LV stroke work may easily be estimated from pressure-volume loops. There was generally good correlation between hemodynamic status assessed from pressure-volume loops and subsequent clinical outcome.
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PMID:Prognostic implications of left ventricular function in endomyocardial disease in infants and children. 12 9

A noninvasive technique, i.e., the intravenous injection of a bolus of 99mTc, allows one to visualize the wall motion and the stroke volume distribution of the left ventricle after myocardial infarction. Thus, in the first weeks after infarction, it is possible 1) to answer the question of the function of the involved wall segment, 2) to detect early complications, 3) to follow-up the course 4) to estimate the patient's functional status for treatment more accurately and 5) to control the result of treatment. Furthermore, one can calculate the ejection fraction, demonstrate other zones of reduced systolic function and evaluate the degree of congestion in the lung and involvement of the right ventricle. The study is based on 42 examinations in 35 patients with proven myocardial infarction. Only three patients presented normal systolic wall motion. In the remaining 32 patients there was hypokinesia of the infarcted segment partly combined with some temporary dyskinesia during ventricular contraction or with localized akinesia. Three patients had an aneurysm, two a ventricular septal defect and 19 some degree of mitral reflux, in seven congestive heart failure was present. Certain technical requirements are essential for this noninvasive technique. They are discussed in detail. Examples of wall motion and stroke volume distribution of a normal left ventricle, anterior and posterior infarction and an aneurysm are illustrated.
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PMID:[Noninvasive demonstration of wall movement and stroke volume distribution of the left ventricle after myocardial infarction (author's transl)]. 13 Oct 77

Clinical, experimental and pathologic studies strongly indicate that hypertension is a major factor in coronary heart disease, sudden death, stroke congestive heart failure and renal insufficiency. The deleterious effect of the elevated blood pressure on the cardiovascular system appears to be due mainly to the mechanical stress placed on the heart and blood vessels. Humoral factors and vasoactive hormones such as angiotensin, catecholamines and prostaglandins may play a role in the pathogenesis of hypertensive cardiovascular disease but this role has not yet been defined and is probably secondary. Hypertension and the resulting increase in tangential tension on the myocardial and arterial walls, leads to the development of hypertensive heart disease and congestive heart failure as well as hypertensive vascular disease that affects not only the kidneys but also the heart and brain. Hypertensive vascular disease involves both large and small arteries as well as arterioles and is characterized by fibromuscular thickening of the intima and media with luminal narrowing of the small arteries and arterioles. The physical stress of hypertension on the arterial wall also results in the aggravation and acceleration of atherosclerosis, particularly of the coronary and cerebral vessels. Moreover, hypertension appears to increase the susceptibility of the small and large arteries to atherosclerosis. Thus the patient with hypertension is a candidate for both hypertensive and atherosclerotic vascular disease of the coronary and cerebral vessels leading to occlusive disease of both the large and small arteries and resulting in myocardial infarction and stroke. Other major complications of hypertensive vascular disease include rupture and thrombotic occlusion of blood vessels, especially in the brain. Disease of the arterial media, which begins in childhood with the deposition of calcium in the vessels, may be an important cause of arterial hypertension. This form of hypertension may manifest itself in adults as arteriosclerotic hypertension and lead to cardiovascular complications very similar to those of essential hypertension. The relation of arteriosclerotic hypertension to nutritional factors, including dietary salt intake, deserves study.
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PMID:Role of hypertension in atherosclerosis and cardiovascular disease. 13 91

Diastolic wall stress and compliance were determined in 74 patients with essential hypertension during diagnostic cardiac catheterization. Ventricular compliance was normal in compensated essential hypertension without coronary artery disease even at severe left ventricular hypertrophy. In contrast, additional coronary stenosis and ventricular dilatation due to cardiac decompensation was asscociated with considerable decrease in ventricular compliance. Thus, left ventricular hypertrophy in essential hypertension does not imply per se a change in ventricular compliance. A decrease in ventricular compliance was followed by a decrease of forward pump function of the left ventricle. whereas ventricular work index (as estimated as the product out of systolic wall stress and the stroke volume) increased. This disproportion between external and internal ventricular work increased with increasing ventricular dilatation and was greatest in decompensated essential hypertension. Accordingly, decompensated essential hypertension had largest ventricular work load and lowest forward pump function in comparison to all other patient groups with essential hypertension. The mass to volume ratio may be considered an important determinant of the degree of left ventricular hypertrophy in essential hypertension. The relationship between the mass to volume ratio and the systolic wall stress may provide a diagnostic and prognostic evaluation of the left ventricle in essential hypertension on the basis of dynamic ventricular geometry.
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PMID:[The heart in hypertension. III. Determinants of left ventricular hypertrophy and diastolic left ventricular compliance (author's transl)]. 15 7

Large volumes of normal saline were infused intravenously in 6 dogs until obvious pulmonary edema was observed radiographically. Following volume overload, statistically significant increases occurred in the size of the heart, left atrium, pulmonary arteries and veins, and systemic veins, without the development of congestive heart failure (CHF). The left ventricular end-diastolic pressure remained normal, and cardiac output and stroke volume increased. The results suggest that, in the absence of left ventricular failure, acute volume overload may simulate the radiographic changes produced by CHF. Pulmonary edema may have occurred at least partly from a marked decrease in serum colloid osmotic pressure.
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PMID:Cardiopulmonary effects of intravenous fluid overload: radiologic manifestations. 15 36

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.
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PMID:Left ventricular function in beta-thalassemia and the effect of multiple transfusions. 16 23

The effects of mechanical ventilation with and without positive end-expiratory pressure (PEEP) on hemodynamic performance and blood-gas exchange were studied in ten patients following open-heart surgery. Ventilation at constant tidal volume (15 ml/kg body weight) with 10 cm H2O PEEP following aortic valve replacement (AVR) IN FIVE PATIENTs without pulmonary vascular disease was associated with the following significant changes: a rise in arterial Po2, a fall in the alveolar-arterial Po2 gradient when Fio2 = 1.0, decreases in calculated Qs/Qt and cardiac index. Using a similar pattern of ventilation following mitral valve replacement (MVR) in patients with elevated pulmonary vascular resistance, we found a significant decrease in cardiac index (but less than in the AVR group), a significant elevation of calculated physiologic deadspace (Vd/Vt) and no change in Qs/Qt. An hour after removal of PEEP, intravascular pressures, blood flow and blood-gas exchange values of all patients with AVR had returned to control levels; patients with MVR had persistently significantly low cardiac indices, while Vd/Vt returned to pre-PEEP values. These findings suggest that evaluation of responses to different ventilation patterns must take into account pre-existing V/Q abnormalities secondary to pulmonary vascular disease, particularly when these are secondary to chronic congestive heart failure. Following AVR, Qs/Qt changed in the same direction as cardiac index (CI) irrespective of ventilatory pattern: CI decreased and rose as CI increased. The authors conclude that with increasing severity of pulmonary vascular disease, changes in airway pressure will have an unpredictable effect on cardiac index unless the level of myocardial competence is taken into account. In the presence of ventricular failure, changes in pleural (and therefore transmural) pressures will be minimal compared with the high filling pressures and exert no influence on stroke volume. Although pulmonary venous hypertension was more pronounded in the MVR than in the AVR group, there was no significant difference between the postoperative values for Qs/Qt (Fio2 = 1.0), a condition probably fostered by marked differences in pre-existing V/Q.
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PMID:The effect of pre-existing pulmonary vascular disease on the response to mechanical ventilation with PEEP following open-heart surgery. 23 11

To evaluate the effectiveness of oral vasodilator therapy in chronic congestive heart failure, 20 mg of isosorbide dinitrate or placebo was administered orally in double-blind fashion to 25 patients with congestive heart failure. In 15 patients receiving isosorbide dinitrate, pulmonary arterial wedge pressure decreased 5 minutes to 5 hours after drug administration; the peak reduction was observed at 1 hour (from 23 to 14 mm Hg; P less than 0.001). Wedge pressure decreased to normal (12 mm Hg or less) in 8 of the 15 patients (Group I) but remained greater than 12 mm Hg in 7 (Group II). Reductions in mean systemic arterial pressure, systemic vascular resistance and pressure-time per minute also occurred. Indexes of pump output were unchanged in the 15 who received isosorbide dinitrate but tended to decrease slightly in Group I. Stroke index (from 23 to 26 cc/m2) and stroke work index (from 21.4 to 24.1 g-m/m2) increased slightly but significantly (P less than 0.05) in Group II. Thus the prinicpal hemodynamic action of isorbide dinitrate is marked and sustained reduction in left ventricular filling pressure without pronounced effect on cardiac output. This agent should be used in congestive heart failure primarily for relief of congestive symptoms.
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PMID:Hemodynamic assessment of oral peripheral vasodilator therapy in chronic congestive heart failure: prolonged effectiveness of isosorbide dinitrate. 31 95

Twelve patients with clinical and hemodynamic evidence of severe congestive heart failure, unresponsive to the usual therapy of salt restriction, oxygen, bed rest, digitalis, and massive doses of diuretics, were studied during a control period and after intravenous dopamine. Seven patients survived and 5 died with intractable failure and shock despite transiently improved hemodynamic indices. At control period and after optimal dose of dopamine, there were no significant changes in heart rate (HR) and mean systemic arterial pressure. The mean pulmonary artery (PA) and pulmonary capillary wedge (PCW) pressures decreased slightly. Cardiac index (CI), stroke volume (SVI), and stroke work indices (SWI) rose (p less than 0.005) from the control values of 1.4 +/- 0.1, 15.3 +/- 5, and 13.6 +/- 1.7 to 2.2 +/- 0.1, 24.1 +/- 4, and 24 +/- 2.3, respectively; pulmonary arteriolar (PAR), total pulmonary vascular (TPVR), and systemic vascular (SVR) resistances fell (p less than 0.01). Urine output increased from 13.5 ml/hr before to 58.2 ml/hr after dopamine (p less than 0.005). After 24 and 48 hr of dopamine, in addition to the above hemodynamic changes, PA pressure fell from 38 +/- 4 to 33 +/- 3 and 28 +/- 2, and PCW from 30 +/- 2 to 24 +/- 3 and 18 +/- 3 (p less than 0.05). Compared with nonsurvivors, survivors had significant decreases in PA and PCW pressures, PAR, and TPVR and an increase in SWI. These data indicate that dopamine is effective in some patients with refractive congestive heart failure associated with acute oliguric renal failure and that the prognosis may be improved.
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PMID:Hemodynamic effects of dopamine in patients with resistant congestive heart failure. 35 38

A feasibility trial to investigate the practicality of determining the advantages and disadvantages of prompt pharmacologic treatment for mild hypertension was jointly funded by the Veterans Administration and the National Heart, Lung and Blood Institute. Its clinical phase has been completed, and it demonstrated 1. that the required relatively young asymptomatic population could be enrolled in the study and 2. that it could be persuaded to adhere to the protocol for 2 years; however, it was evident that intensive efforts would be required in both areas. The feasibility trial screened almost 120,000 potential subjects over a period of 16 months to randomize about 1,000 subjects at four clinical centers. These men and women were 21 to 50 years old, had diastolic pressures from 85 to 105 mm Hg as outpatients, and had no evidence of cardiovascular renal abnormalities. They were randomized in double-blind fashion into active drug therapy and placebo groups. Stepped care therapy involved 50 mg chlorthalidone (Step 1), 100 mg chlorthalidone (Step 2) and 100 chlorthalidone plus 0.25 mg reserpine (Step 3). Death, myocardial infarction, stroke, angina pectoris, and congestive heart failure were the "major" morbid events that were looked for; also recorded were "minor" morbid events consisting primarily of electrocardiographic arrhythmias. The development of significant hypertension was considered a treatment failure. Side effects were carefully tabulated in both active drug and placebo groups. The study revealed an average drop in diastolic pressure of almost 12 mm Hg for active drug group and less than half of that for the placebo group; once established 6 months after randomization, the new pressure levels persisted almost without change throughout the study. Although the feasibility trial was not designed to answer the primary question regarding the benefits of treatment, the events were tabulated for each group. A total of 12 placebo-treated subjects developed significant hypertension and were put on active drug. There was not a significant difference between the two groups in the incidence of "major" morbid events; a total of eight active and five placebo patients developed myocardial infarction or died suddenly. There, however, was an excess of arrhythmias among the active drug subjects (17 in the active group versus 8 in the placebo group on the basis of preliminary data). Finally, there were twice as many side effects and 20 times as many chemical abnormalities among the active as among the placebo subjects. A protocol for a full scale study of the benefits of pharmacologic therapy in mild hypertensives has been prepared and is ready for implementation as needed; it involves relatively minor modifications of the protocol tested in the feasibility trial.
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PMID:Evaluation of drug treatment in mild hypertension: VA-NHLBI feasibility trial. Plan and preliminary results of a two-year feasibility trial for a multicenter intervention study to evaluate the benefits versus the disadvantages of treating mild hypertension. Prepared for the Veterans Administration-National Heart, Lung, and Blood Institute Study Group for Evaluating Treatment in Mild Hypertension. 36 Sep 21


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