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Query: UMLS:C0018801 (heart failure)
 72,216 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Of the vasodilators used at present in the treatment of heart failure, only nitroprusside and phentolamine inhibit platelet aggregation at therapeutic dose levels. The other vasodilators studied, viz. nitroglycerin, isosorbide dinitrate, hydrallazine, dihydrallazine and prazosin, only inhibit platelet aggregation at relatively high concentrations, well above those reached in vivo. The exact nature of the platelet receptor, stimulation and blockade of which respectively initiate and inhibit aggregation, is not yet know, but it would appear to resemble the presynaptic alpha-receptors of other tissues.
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PMID:Influence of vasodilators used in the therapy of heart failure on platelet aggregation. 47 7

Of 88 consecutive patients aged 20 to 77 years with severe symptomatic aortic valve disease requiring surgery, 51 patients had angina pectoris; of these 51, 41 had predominant aortic stenosis and 10 had severe aortic regurgitation. All patients with angina pectoris underwent coronary angiography; significant coronary arterial disease was encounted in 24 per cent of those with aortic stenosis and 20 per cent of those with aortic regurgitation. By contrast, of 37 patients without angina pectoris 19 underwent coronary arteriography; none showed significant coronary artery disease (P smaller than 0.05). Among patients with angina pectoris, 17 per cent of those with aortic stenosis experienced prolonged, rest or nocturnal pain, compared to 70 per cent of those with aortic regurgitation (P smaller than 0.005). At the time of onset of angina pectoris, there were features of heart failure in 34 per cent of those with aortic stenosis, and in 90 per cent of those with aortic regurgitation (P smaller than 0.005). Nitroglycerin promptly relieved angina pectoris in 56 percent of patients with aortic stenosis and in 50 per cent of those with aortic regurgitation (P smaller than 0.05). Neither the pattern of angina pectoris nor the response to nitroglycerin was dependent upon the coexistence of significant coronary artery disease. In patients with aortic stenosis, there was not significant difference between those with angina pectoris, and those without angina with regard to left ventricular end-diastolic volume, end-diastolic pressure, ejection fraction, peak systolic pressure, wall thickness, cardiac index, or the product of these factors. In patients with aortic regurgitation, cardiac index was significantly lower (P smaller than 0.05), left ventricular end-diastolic volume tended to be larger, and ejection fraction tended to be lower in patients with angina pectoris as opposed to those without angina pectoris.
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PMID:Clinical, haemodynamic, and coronary angiographic correlates of angina pectoris in patients with severe aortic valve disease. 80 13

Patients with cardiac disorders have defective parasympathetic control of heart rate. To evaluate the possibility of similar changes in sympathetic control of heart rate, we compared reflex chronotropic responses to 80 degree upright tilt and nitroglycerin-induced hypotension in 31 cardiac patients and 7 normal individuals before and after partial parasympathetic blockade with atropine. Tilting revealed an attenuation of the normal heart rate increase in patients; the magnitude of this defect was greatest in patients with more severe symptoms (class III) and evidence of left ventricular dysfunction (the heart rate increase averaged 25 plus or minus 3 beats/min in normal subjects, 12 plus or minus 2 beats/min in class I-II patients, and 7 plus or minus 1 beats/min in class III patients). Class III symptoms due to mechanical causes (mitral stenosis), however, were not associated with this defect. A marked reduction in heart rate rise with hypotension was seen only in those class III patients without mitral stenosis (0.4 plus or minus 0.1 beats min-minus 1 mm Hg-minus 1 vs. 3.0 plus or minus 0.5 beats min-minus 1 mm Hg-minus 1 in normal subjects). This abnormality also persisted after atropine administration, thus confirming a defect in the sympathetic as well as the parasympathetic component of baroreceptor-mediated reflex heart rate control in patients with cardiac dysfunction. Infusions of isoproterenol produced equivalent rises in heart rate in patients and normal individuals, excluding a reduction in beta-receptor responsiveness as a cause of impaired sympathetic influence. Norepinephrine depletion, however, is a well-recognized concomitant of cardiac failure. It is possible that the reduction in sympathetically mediated heart rate responses results in part from depletion of the sympathetic neurotransmitter.
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PMID:Impairment of autonomically mediated heart rate control in patients with cardiac dysfunction. 80 57

The evaluation of left ventricular function in patients with acute myocardial infarction has shown: 1. Limitations in the use and interpretation of central venous pressure. 2. Pulmonary artery end-diastolic pressure reflects left ventricular end-diastolic pressure in the absence of pulmonary vascular or mitral valve disease. 3. Frequent elevations of left ventricular filling pressure in mild or clinically uncomplicated infarction. 4. Anterior infarctions present greater depression of left ventricular function than inferior infarctions. 5. Initial hemodynamic measurements in cardiogenic shock can predict prognosis with medical management. 6. Left ventricular function frequently improves during the early convalescent period. 7. Hemodynamic monitoring can be useful in following changes in left ventricular function and the response to therapy. The assessment of left ventricular performance in patients with chronic heart disease has shown: 1. Resting hemodynamic measurements are often normal but abnormalities can be observed in patients with disease of the left anterior descending coronary artery, diffuse coronary involvement, and after myocardial infarction. 2. Increases in end-diastolic volume or dilatation and left ventricular mass or hypertrophy can develop in severe coronary disease and after myocardial infarction. 3. The size of abnormally contracting segment after myocardial infarction is related to abnormalities in compliance, ventricular end-diastolic pressure, end-diastolic volume, and clinical manifestations of heart failure. 4. Exercise and atrial pacing can produce clinical and hemodynamic abnormalities. 5. The ejection fraction is significantly related to the slope of the ventricular function curve. 6. Angiographic abnormalities of left ventricular wall motion can be increased with atrial pacing and reduced with nitroglycerin or epinephrine.
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PMID:Left ventricular function in acute and chronic coronary artery disease. 80 47

Vasodilators are known to be effective in improving the hemodynamics of congestive heart failure by increasing cardiac output and reducing left ventricular filling pressure (LVFP). Long acting agents are needed to augment the practicality and availability of chronic vasodilator therapy. In the present study the vascular effects of chewable isosorbide dinitrate (CHIS), sublingual nitroglycerin (NTG) and placebo (P) were compared in eight patients with high LVFP due to heart failure. Patients with LVFP (pulmonary wedge pressure) over 14 mm Hg were given CHIS, 10 mg, NTG, 0.6 mg, and P, two chewable tablets, in random fashion. Heart rate (HR), blood pressure (BP) and LVFP were monitored for three hours after each drug. HR was not significantly affected by any drug, although it rose slightly after NTG and fell after CHIS. Significant reduction of BP occurred only after NTG, with peak effect at five minutes, but lasting only 15 minutes. NTG reduced LVFP 5.1 mm Hg (19.5%, P, less than 0.05), at peak effect, but LVFP was no longer significantly lower by 20 minutes after NTG. After CHIS, LVFP fell significantly within five minutes, reached a peak reduction of 8.6 mm Hg (32;7%, P less than 0.01) at 15 minutes, and remained significantly lower through three hours. Thus CHIS provides a nitrate action of rapid onset and sustained effect that may be useful for chronic vasodilator therapy of heart failure.
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PMID:Comparative hemodynamic effects of chewable isosorbide dinitrate and nitroglycerin in patients with congestive heart failure. 80 59

Nitroglycerin reduces ischemic injury during acute myocardial infarction (AMI) in dogs--an effect that is potentiated when drug-induced hypotension and tachycardia are prevented with phenylephrine. To determine the effectiveness of nitroglycerin, alone or with phenylephrine, during AMI in man, 12 patients (five or whom had left heart failure) were evaluated by summing ST-segment abnormalities (sigmaST) from 35 precordial electrodes. The seven patients without heart failure did not benefit consistently from nitroglycerin alone; however, addition of phenylephrine to abolish nitroglycerin-induced arterial pressure reduction uniformly diminished sigmaST (4.9 to 3.2 mv; P less than 0.05). In patients with heart failure, nitroglycerin alone consistently reduced ischemia (5.8 to 4.4 mv, P less than 0.05); addition of phenylephrine often partially reversed this effect. Thus, administration of nitroglycerin, alone or with phenylephrine, can reduce myocardial ischemic injury during AMI in man; however, the response to phenylephrine depends on the presence or absence of left ventricular failure before treatment.
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PMID:Reduction in myocardial ischemia with nitroglycerin or nitroglycerin plus phenylephrine administered during acute myocardial infarction. 80 12

Effective vascular compliance determined by the delta V/delta P relationship was measured repeatedly in anesthetized open-chest dogs without circulatory arrest utilizing a closed circuit venous bypass system with a constant cardiac output. Production of acute heart failure by gradual aortic constriction was associated with a significant decrease in total effective vascular compliance. The effect of loading and 20-min maintenance doses of different drugs on vascular compliance of animals in acute heart failure was studied. Phenoxybenzamine (total dose 2 mg/kg) produced a rapid and sustained increase in effective vascular compliance and theophylline (12 mg/kg) produced an increase which was more gradual in development than with phenoxybenzamine. Morphine (1 mg/kg) produced a rapid but transient increase in compliance. In contrast, ethacrynic acid (100 mg) or nitroglycerin (0.6 or 1.2 mg) did not alter vascular compliance significantly. These agents differ markedly in the magnitude and time-course of effect on effective vascular compliance.
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PMID:Effect of drugs on effective vascular compliance in acute heart failure. 81 37

Acute changes in the diastolic pressure-volume relationship of the left ventricle. Europ. J. Cardiol., 4/Suppl., 105-120. The present study was designed to investigate acute changes in the passive length-tension relations of isolated heart muscle and acute alterations of the left ventricular diastolic pressure-volume relationship of patients. In isolated heart muscle a constant lengthening and shortening technique with computer curve fitting was used to characterize the entire passive length-tension relation. There was no change in passive elastivity following an increase in stimulation frequency or an increase in muscle stretching rate. During the transition from stimulated to nonstimulated contractions, there was a shift to the left in the passive length-tension relation, with a shorter muscle length at the same resting force. In 10 patients undergoing revascularization for preinfarction angina, 7 patients showed a significantly reduced left ventricular enddiastolic pressure at the same enddiastolic volume, together with an improvement in postoperative ejection fraction. In 6 patients who experienced a perioperative myocardial infarction, variable changes in the pressure volume relationship occurred. These presumably reflected the opposite effects of stiffening of infarcted muscle and cardiac dilatation secondary to heart failure. 26 patients with chronic coronary artery disease had ventriculograms before and after 0.4 mg sublingual nitroglycerin. 9 patients showed a significant shift downwards in their pressure-volume relation, with a decreased enddiastolic pressure at the same volume. 2 showed a shift upwards, while the remaining patients showed no measurable change. It is proposed that this latter shift in pressure-volume relationships is due to hemodynamic factors rather than to intrinsic changes in muscle stiffness. Theoretical calculations utilizing A SIMPLIFIED SPHERICAL MODEL of the ventricle suggest that the magnitude of the changes observed cannot be explained by stiffening of the muscle alone and is therefore probably due to hemodynamic factors.
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PMID:Acute changes in the diastolic pressure-volume relationship of the left ventricle. 81 75

A patient with severe, chronic congestive heart failure was unresponsive not only to conventional therapy, but also to nonparenteral nitroglycerin and isosorbide dinitrate; he became nitroprusside dependent. Oral minoxidil therapy produced a significant decrease in systemic vascular resistance and an increase in cardiac output, with no tachycardia, hypotension, or decrease in systemic and pulmonary venous pressures. The addition of sublingual isosorbide dinitrate decreased venous pressures and produced a further increase in cardiac output. The combination of oral minoxidil and sublingual isosorbide dinitrate maintained clinical and hemodynamic improvements, and the patient could be weaned off nitroprusside. Deterioration in hemodynamics occurred with the withdrawal of minoxidil. Therapy with oral hydralazine produced hemodynamic effects comparable to those of oral minoxidil. These observations suggest that chronic reduction of impedance to left ventricular ejection with minoxidil or hydralazine is possible in patients with severe intractable heart failure and deserves further clinical trial.
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PMID:Combination vasodilator therapy for severe chronic congestive heart failure. 82 52

Vasodilative treatment of severe heart failure with infusions of phentolamine leads to ventricular unloading and in many cases brings about a dramatic improvement of the patient's condition. Phentolamine is the only one of the vasodilators so far used in the treatment of heart failure that has a positively inotropic effect. In contrast to sodium nitroprusside and nitroglycerin, it also increases stroke volume at normal filling pressures. Although vasodilative therapy has resulted in a notable decline in the mortality from severe heart failure among hospitalized patients, the long-term prognosis after discharge remains poor. One of the chief reasons is that there has hitherto been no effective orally administrable drug suitable for protracted therapy. Initial clinical studies with a newly developed slow-release formulation of phentolamine have shown that the preparation produces remarkably good effects in patients with chronic heart failure: systolic pressure rises, the amplitude of the blood pressure is augmented and there is an increase in urinary excretion accompanied with a corresponding reduction in weight. In practically all cases, there is a distinct decrease in the size of the heart and in pulmonary congestion.
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PMID:[Treatment of heart failure with phentolamine (Regitin)]. 89 48


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