Hemodynamic advantage of combined administration of hydralazine orally and nitrates nonparenterally in the vasodilator therapy of chronic heart failure

Combined hemodynamic effects of nifedipine and nitroglycerin in congestive heart failure

To determine if the addition of preload reduction with nitrates would potentiate the acute vasodilator actions of nifedipine, we titered intravenous nitroglycerin in seven patients with severe congestive heart failure after they received a single oral dose of nifedipine. The peak hemodynamic effect of nifedipine occurred at 30 minutes, with large reductions of systemic vascular resistance (1831 +/- 128 to 1132 +/- 154 dynes X sec X cm-5; p less than 0.001) and mean arterial pressure (87 +/- 7 to 71 +/- 7 mm Hg; p less than 0.01). This was associated with an increase of stroke volume index from 22 +/- 3 to 27 +/- 3 ml/m2 (p less than 0.01) but no significant changes in heart rate, right atrial pressure, or pulmonary wedge pressure. These hemodynamic changes were attenuated over a 2-hour observation period. At 2 hours, the addition of intravenous nitroglycerin resulted in large reductions in right atrial pressure (9 +/- 2 to 6 +/- 1; p less than 0.01) and pulmonary wedge pressure (23 +/- 2 to 17 +/- 2; p less than 0.001). This was associated with further increases in cardiac index (from 1.99 +/- .15 to 2.25 +/- .14 L/min/m2; p less than 0.001) and stroke volume index (26 +/- 3 to 29 +/- 3 ml/m2; p less than 0.01). Thus, the addition of nitroglycerin to nifedipine will optimize preload reduction and enhance the vasodilator action of nifedipine. Further controlled studies are necessary to determine the long-term hemodynamic effects and the clinical role of nifedipine and its combination with nitrates in patients with severe congestive heart failure.

Role of isosorbide dinitrate in management of chronic congestive heart failure

Congestive heart failure is accompanied by a number of compensatory mechanisms that may overshoot the mark. Among these are excessive arteriolar and venous constriction. Nitrates are effective in producing venodilation, redistributing blood from the chest to the periphery, and lowering right and left atrial pressures. Although oral isosorbide dinitrate is effective in producing acute beneficial hemodynamic effects, it usually does not increase exercise tolerance in the short term. Prolonged administration, however, does increase exercise tolerance and improve clinical class. Isosorbide dinitrate can be effectively combined with an arteriolar dilator such as hydralazine, which increases cardiac output. Such vasodilator therapy is symptomatically effective in patients with heart failure, although there is no evidence to date to suggest a prolongation of life.

Role of vasodilators in the treatment of congestive heart failure

Appreciation of the important role played by peripheral vasoconstriction in the pathophysiology of congestive heart failure (CHF) has led to the widespread use of vasodilators as treatment. Short-term studies show that, regardless of the vasodilator used, the arterial and venous dilatation produced invariably results in improvement in the hemodynamic status of patients. This short-term response, however, does not automatically translate to long-term clinical improvement. The reasons for this are not well understood but such factors as differing mechanisms of action, development of tolerance and unique patterns of regional redistribution of blood flow may all play a modifying role in differentiating one vasodilator from another. Nevertheless, a number of controlled trials have demonstrated sustained symptomatic and functional improvement when vasodilators such as the converting enzyme inhibitors or nitrates are given to patients with CHF.

Noninvasive assessment of acute effects of nifedipine on rest and exercise hemodynamics and cardiac function in patients with aortic regurgitation

The acute effects of nifedipine (20 mg sublingually) on hemodynamics and cardiac function were studied at rest and during supine bicycle exercise in 20 patients with aortic regurgitation. At rest, heart rate increased by 13%, systemic vascular resistance decreased by 34% and regurgitant index decreased by 17%. The change in systemic vascular resistance was related to its initial rest level (r = 0.82, p less than 0.001) and to the changes in forward cardiac output (r = 0.58, p less than 0.01) and regurgitant index (r = 0.60, p less than 0.01). Left ventricular end-diastolic and end-systolic volumes, stroke volume and ejection fraction were unchanged, whereas right ventricular ejection fraction increased. During exercise, nifedipine administration further increased heart rate by 8% and decreased systemic vascular resistance by 19%. Both forward stroke volume and forward cardiac output increased, but total left ventricular stroke volume was unchanged, resulting in a significant decrease in regurgitant index. Although left ventricular end-diastolic volume was slightly decreased, end-systolic volume did not increase; thus, ejection fraction was higher than that during control exercise (p less than 0.01). Right ventricular ejection fraction increased further. In aortic regurgitation, the acute administration of nifedipine improved cardiac performance and reduced regurgitation at rest and during exercise as a result of afterload reduction and increased heart rate. Whether these beneficial effects will occur during long-term therapy requires further investigation.

Conceptual dilemmas in the classification of vasodilator drugs for severe chronic heart failure. Advocacy of a pragmatic approach to the selection of a therapeutic agent

Two distinct systems of classifying vasodilator drugs have been developed over the past decade in an attempt to guide the choice of a therapeutic agent for the patient with severe heart failure, but the merits and utility of these systems have not been critically evaluated. Vasodilator drugs may be categorized according to their peripheral site of action: an agent may exert its effects preferentially on systemic arteries, systemic veins, or on both circulations. However, changes in the peripheral circulation cannot be directly translated into an improvement in central hemodynamic variables; furthermore, immediate hemodynamic responses may not be predictive of long-term clinical efficacy. Hence, there is no evidence that characterization of patients into hemodynamic subsets determined by the findings of right heart catheterization improves the clinical outcome of vasodilator therapy in chronic heart failure. An alternative classification system groups vasodilator drugs according to their mechanism of action: an agent may possess direct vasodilating effects or may exert its actions via selective neurohumoral inhibition. However, attempts to identify patients who might be most responsive to neurohumoral antagonism by measuring plasma renin activity or circulating levels of catecholamines before treatment have not been successful in predicting the clinical responses to therapy. Because neither system of drug classification provides the clinician with useful therapeutic guidelines, patients with severe heart failure appear to be best managed using a pragmatic approach in which specific drugs that produce predictable therapeutic benefits with a low frequency of side effects are utilized preferentially. Among presently available vasodilator agents, only captopril and oral isosorbide dinitrate have been shown to produce consistent hemodynamic and clinical improvement with an acceptable degree of adverse reactions.

Vasodilator and inotropic therapy for severe chronic heart failure: passion and skepticism

Although substantial progress has been made in the last 5 years in the development of vasodilator and inotropic drugs for the management of patients with severe chronic heart failure, much of the enthusiasm that surrounded the introduction of many of these agents has subsequently been tempered by reports of drug failure or adverse reactions. In this review and analysis, currently available vasodilator and inotropic agents are critically and comparatively evaluated to assess their respective advantages and limitations. It is apparent that the ability of most of these drugs to produce substantial clinical benefits in patients with severe heart failure has probably been overstated. Therapy fails to achieve the desired clinical results all too frequently, possibly as the result of: the choice of an ineffective drug; the administration of an effective drug in subtherapeutic doses; the administration of an effective drug to improperly selected patients; the failure of initial hemodynamic benefits to be sustained; the occurrence of severe or serious adverse reactions; and the failure to alter concomitant therapy appropriately. The present analysis indicates that there is no uniformly effective or safe vasodilator or inotropic drug for patients with severe heart failure; all agents have important limitations. Of the available therapeutic choices, however, long-term converting enzyme inhibition appears to produce more consistent hemodynamic and clinical benefits with an acceptable degree of adverse reactions than other pharmacologic approaches for the management of these severely ill patients.

Vasodilator therapy in chronic congestive heart failure

Vasodilator agents are relatively new additions to the armamentarium for the management of patients with congestive heart failure. Myocardial failure, irrespective of the aetiology, tends to create a vicious cycle characterised by reduced cardiac output and elevated systemic vascular resistance, which further decrease cardiac output by increasing left ventricular ejection impedance. The rationale for the use of vasodilators is to interrupt the vicious cycle by decreasing the left ventricular ejection impedance by peripheral vasodilatation. Although most vasodilator agents produce qualitatively similar haemodynamic responses, quantitatively their haemodynamic effects differ considerably. Knowledge of the haemodynamic effects of the various vasodilators helps in the selection of a particular drug for the management of such patients. This article reviews the mechanisms of action, haemodynamic effects, pharmacokinetics, clinical usage and adverse effects of non-parenteral vasodilator agents currently available for the management of patients with chronic heart failure.

Hemodynamic responses to combined therapy with captopril and hydralazine in patients with severe heart failure

The hemodynamic benefits and safety of combined therapy with captopril and hydralazine were studied during invasive hemodynamic monitoring in 14 patients with severe heart failure. In eight patients, the individual effects of both drugs were evaluated before the administration of combined therapy, whereas hydralazine was added to maintenance captopril therapy in the other six patients. In the first group, captopril alone produced a marked decrease in pulmonary wedge pressure (28 +/- 4 to 18 +/- 5 mm Hg) and mean arterial pressure (85 +/- 20 to 69 +/- 13 mm Hg) (both p less than 0.001) without a significant increase in cardiac index. Hydralazine alone produced a marked increase in cardiac index (1.6 +/- 0.4 to 2.7 +/- 0.5 liters/min per m2) (p less than 0.001), but with a minimal decrease in pulmonary wedge pressure (28 +/- 4 to 23 +/- 4 mm Hg) (p less than 0.05) and without a significant change in mean arterial pressure. The combination of captopril and hydralazine produced an increase in cardiac index similar to that of hydralazine alone and decreases in pulmonary wedge pressure and mean arterial pressure similar to those with captopril alone. Most important, when hydralazine was added to captopril in the entire group of 14 patients, cardiac index increased markedly with little additional decrease in mean arterial pressure and no significant increase in heart rate. The one patient who experienced symptomatic hypotension with combination therapy also had dizziness with captopril alone. Seven of the nine patients maintained on long-term treatment experienced symptomatic improvement. Thus, in patients with severe chronic heart failure, the combined use of captopril and hydralazine is feasible and produces acute hemodynamic improvement superior to that from either drug alone.

A radionuclide method for the simultaneous study of the effects of drugs on central and peripheral haemodynamics

1 The central and peripheral cardiovascular effects of hydralazine and glyceryl trinitrate (GTN) have been contrasted using radionuclide techniques.

2 Following intravenous injection of technetium-99m labelled human serum albumin, radionuclide ventriculography was performed by the equilibrium blood pool method using a mobile gamma camera. Simultaneous measurements of `peripheral venous volume' were made using a collimated scintillation probe positioned above the patient's calf.

3 Ten patients with angina pectoris were studied at rest, after sublingual administration of 0.5 mg GTN and after intravenous administration of 10 mg hydralazine.

4 GTN caused a mean reduction in the end diastolic volume of the left ventricle of 14.6% ± 4.5% (P < 0.005) but ejection fraction increased by 0.034 ± 0.007 (P < 0.005) so that stroke volume was only reduced by 4.9% ± 5.0% (NS). There was a mean increase in heart rate of 10.8 ± 2.3 beats/min (P < 0.001) but no significant change in cardiac output. The calculated systemic vascular resistance fell by 10.0% ± 5.4% (P < 0.05). Associated with these changes there was a mean increase of 9.6% ± 1.5% (P < 0.05) in the counts from the calf.

5 Hydralazine caused a significant reduction in blood pressure and increase in heart rate. End-diastolic volume was reduced by 6.0% ± 2.7% but there was a mean increase in ejection fraction of 0.058 ± 0.010 (P < 0.001) so that in this instance stroke volume increased by 9.0% ± 3.7% (P < 0.05) and cardiac output increased by 16.4% ± 4.4% (P < 0.005). The calculated systemic vascular resistance fell by 18.9% ± 3.8% (P < 0.001). Despite these haemodynamic changes there was no significant change in counts from the calf.

6 The results confirm that GTN has a predominant venodilator effect while hydralazine acts largely on the arterial bed. These relatively simple radionuclide methods will allow a more detailed assessment of the cardiovascular effects of drugs.

Acute hemodynamic effects of endralazine: a new vasodilator for chronic refractory congestive heart failure

Invasive hemodynamic measurements were made in 10 supine patients with chronic refractory congestive heart failure (CHF) due to ischemic heart disease or cardiomyopathy before and after oral administration of a new arteriolar vasodilator, endralazine. In 9 patients, a 10 mg dose of endralazine produced maximal increases in cardiac and stroke volume indexes of 56 and 41%, respectively, with a 45% reduction in total systemic resistance. After a 5 mg dose of endralazine, cardiac index increased maximally by 38% and stroke volume index by 34%, with a 31% decrease in total systemic resistance. Mean arterial pressure decreased 11 +/- 4 mm Hg (mean +/- standard error of mean) with the 5 mg dose and 17 +/- 5 mm Hg after the 10 mg dose. There were no significant changes in the right atrial, pulmonary arterial, or pulmonary capillary wedge pressures. After administration of a single dose of endralazine, statistically significant hemodynamic changes were observed from 1 to 8 hours with peak responses at 3 to 4 hours. These observations suggest that endralazine has hemodynamic properties similar to those of its structural analog, hydralazine. However, endralazine metabolism is largely independent of the patients' acetylator status, and no cases of systemic lupus erythematosus have been reported after long-term oral administration. These findings suggest that endralazine may be an efficacious drug that is potentially safer than hydralazine in the treatment of chronic CHF.

Regression of myocardial cellular hypertrophy with vasodilator therapy in chronic congestive heart failure associated with idiopathic dilated cardiomyopathy

Forty-nine patients with idiopathic dilated cardiomyopathy (IDC) were evaluated to determine the hemodynamic and morphologic effects of vasodilator therapy. Hydralazine (225 mg/day, H), isosorbide dinitrate (160 mg/day, I), and combination H + I therapy were compared with placebo (P) at baseline and after 3 months of continuous therapy. Thirty-three randomly assigned patients completed the study. Hemodynamic parameters included the echocardiographic percent change of left ventricular diameter (% delta D), the systolic time intervals ratio of preejection period to left ventricular ejection time (PEP/LVET), the pulmonary capillary wedge pressure, mean pulmonary artery pressure, cardiac index, systemic vascular resistance, and pulmonary vascular resistance. An endomyocardial biopsy was performed at baseline and after 3 months; the myocardial cell diameter of 50 cells per biopsy was measured. During the 3-month study 5 patients died; there was not a significant difference among the groups in the number of deaths. The % delta D and PEP/LVET did not change in the P or I groups but did improve significantly from baseline in the H and H + I groups. The pulmonary capillary wedge and mean pulmonary artery pressures and the pulmonary vascular resistance did not change in the P or H groups but did decrease significantly in the I and H + I groups. The P and I groups did not have improvement in systemic vascular resistance or cardiac index, whereas the H group had a decrease in systemic vascular resistance and an increase in cardiac index from 2.5 +/- 0.4 to 3.1 +/- 0.4 liters/min/m2 (p less than 0.05). The H + I group also had a decrease in systemic vascular resistance; the cardiac index increased from 2.3 +/- 0.4 to 3.1 +/- 0.4 liters/min/m2 (p less than 0.01). Myocardial cell diameter did not change in the P or I group. Cell diameter of the H group decreased from 25.4 +/- 3.1 microns at baseline to 23.1 +/- 3.8 microns (p less than 0.05) after 3 months of continuous therapy. The H + I group decreased its cell diameter from 23.9 +/- 3.7 to 22.2 +/- 2.2 microns (p less than 0.05). Compared with P and H, patients treated with I alone or H + I had a significant reduction of preload. In contrast to P and I, H alone and H + I elicited improvement in parameters of inotropy and afterload, and this improvement was accompanied by a reduction in cell diameter. Chronic therapy of heart failure with H and H + I effects a persistent augmentation of cardiac function and improvement of myocardial cellular morphology.

Vasodilator therapy for acute myocardial infarction and chronic congestive heart failure

Vasodilator therapy is useful adjunctive therapy in the management of both acute and chronic heart failure. Arteriolar dilators, such as hydralazine, increase cardiac output by decreasing the elevated peripheral vascular resistance that occurs in heart failure. Venodilators, such as nitrates, decrease ventricular filling pressures by redistributing blood so that more is pooled in peripheral veins. Vasodilators that produce both effects (nitro-prusside, prazosin, captopril, for example) are usually helpful in short-term improvement of hemodynamics. Long-term treatment with nonparenteral vasodilators often reduces symptoms and increases exercise tolerance, although there is inconclusive evidence regarding the effects of these agents on mortality. In acute myocardial infarction, intravenous vasodilators frequently improve cardiac performance. Evidence regarding their beneficial effects on infarct size and immediate mortality is encouraging but inconclusive. There is little evidence that they prolong life in patients who survive cardiogenic shock and leave the hospital. Thus, vasodilators can improve hemodynamics and lessen symptoms, but more evidence is needed regarding their long-term effects on survival.

Vasodilator therapy of severe congestive heart failure: the special importance of angiotensin-converting enzyme inhibition with captopril

Successful ambulatory afterload reduction therapy of severe chronic congestive heart failure (CHF) required the extensive evaluation of hemodynamic effects of vasodilator agents, precise characterization of differential cardiocirculatory actions, and objective confirmation of extended salutary improvements of the heart failure state. This article describes results of a series of investigations with the angiotensin-converting enzyme (ACE) inhibitor captopril (CPT) in several patients with severe CHF. CPT causes predominant peripheral venodilation, resulting in marked decline in elevated left ventricular preload and modest augmentation of the depressed cardiac output. These hemodymanic effects of oral CPT are similar to the effects of nitroprusside and prazosin on increased ventricular preload, but the latter vasodilators cause greater rise in low cardiac pump output. Importantly, the beneficial cardiocirculatory action of oral CPT provided prolonged cardiac benefits with symptomatic improvements confirmed by objective enhancement in left ventricular function documented by cardiac catheterization, echocardiography, nuclear scintigraphy, and treadmill exercise. Thus, ACE inhibition with oral CPT successfully provides marked long-term augmentation of cardiac performance and clinical status in refractory CHF.

Acute and long-term effects of captopril on exercise cardiac performance and exercise capacity in congestive heart failure

Although many studies have shown that captopril (CPT) provides acute hemodynamic improvement in patients with severe congestive heart failure (CHF) at rest, little information is available concerning exercise hemodynamic responses to CPT or the effect of this drug on exercise tolerance in CHF. Therefore, we evaluated the hemodynamic effects of CPT at rest and during upright bicycle exercise in 15 patients with stable CHF. CPT (25 to 50 mg) reduces both resting heart rate and mean arterial pressure (84 +/- 11 to 78 +/- 7 bpm, p less than 0.025 and 85 +/- 9 to 64 +/- mm Hg, p less than 0.001). Concomitantly, left ventricular filling pressure dropped dramatically (26 +/- 9 to 15 +/- 7 mm Hg, p less than 0.001), while cardiac and stroke indices rose (2.0 +/- 0.5 to 2.5 +/- 0.6 L/min/m2, p less than 0.001, and 25 +/- 8 to 33 +/- 7 ml/m2, p less than 0.001). Similar directional changes occurred during exercise, with heart rate, mean arterial pressure, and left ventricular filling pressure at maximum exercise being less (123 +/- 15 to 115 +/- 16 bpm, p less than 0.01; 93 +/- 17 to 86 +/- 14 mm Hg, p less than 0.05; and 35 +/- 10 to 30 11 mm Hg, p less than 0.001, respectively) after CPT ingestion. Peak exercise cardiac index rose slightly (3.6 +/- 0.7 to 3.9 +/- 0.6 L/min/m2) but not significantly. Six patients followed long term on CPT underwent elective recatheterization after 3 months. In these, the beneficial hemodynamic changes seen acutely persisted or further improvement was noted, both at rest and during exercise. Most impressively, peak exercise cardiac index rose from 3.6 +/- 0.7 to 4.6 +/- 1.0 L/min/m2 (p less than 0.05), and this was associated with an increase in exercise duration (8.0 +/- 2.2 to 11.5 +/- 1.4 minutes, p less than 0.05) and exercise work load (332 +/- 32 to 468 +/- 52 kp-m/min, p less than 0.05). These findings indicate that in patients with severe CHF, oral CPT provides markedly beneficial augmentation of cardiac function during activity as well as at rest; moreover, chronic CPT therapy substantially increases exercise capacity in this setting.

Acute and long-term effects of captopril on left and right ventricular volumes and function in chronic heart failure

To more fully delineate the effects of captopril (CPT) on cardiac size and function in patients with chronic congestive heart failure (CHF), we performed blood pool scintigraphy in conjunction with hemodynamic measurements during the initiation of vasodilator therapy and repeat scintigraphy after 2 and 12 weeks. Measurements of both right and left ventricular volumes and ejection fraction were made before and 90 minutes after the first 25 mg dose of CPT in 14 patients. Overall, heart rate fell modestly, from 82 +/- 10 to 77 +/- 11 bpm (p less than 0.01), while mean arterial pressure dropped considerably, from 86 +/- 10 to 73 +/- 13 mm Hg (p less than 0.01). Left ventricular end-diastolic and end-systolic volumes fell from 388 +/- 81 to 350 +/- 77 and 319 +/- 75 to 271 +/- 75 ml (both p less than 0.01). Right ventricular end-diastolic and end-systolic volumes also decreased. The left ventricular ejection fraction rose modestly but significantly, from 19 +/- 6% to 22 +2- 5% (p less than 0.01), as did right ventricular ejection fraction (25 +/- 9% to 29 +/- 11%, p less than 0.01). Simultaneous hemodynamic measurements demonstrated corresponding decreases in left and right ventricular filling pressures (24 +/- 10 to 17 +/- 9 to 10 +/- 5 to 6 +/- 5 mm Hg, respectively, both p less than 0.001). The slight increase in cardiac and stroke indices at 90 minutes, from 2.0 +/- 0.5 to 2.1 +/- 0.4 and 25 +/- 8 to 27 +/- 7 ml/m2, respectively, were not significant, although both indices rose significantly at the time of each individual's peak effect. Six patients were discharged on CPT and underwent follow-up nuclear studies: the acute decrease in ventricular volumes were sustained, as was the slight improvement in ejection fractions. These findings indicated that the major acute effect of CPT in CHF is a reduction in the preload of both ventricles. This reduction in diastolic volumes and pressures persists during chronic therapy.

Comparative analysis of the hemodynamic actions of captopril and sodium nitroprusside in severe chronic congestive heart failure

The hemodynamic actions of the systemic vasodilators parenteral sodium nitroprusside (NP) and oral captopril (CPT) were compared in 11 patients with severe chronic congestive heart failure (CHF). While two agents produced similar reductions in mean blood pressure (NP, 90 to 70 mm Hg vs CPT, 88 to 74 mm Hg, p greater than 0.05) and left ventricular (LV) filling pressure (NP, 27 to 14 mm Hg vs CPT, 24 to 15 mm Hg, p greater than 0.05), they produce disparate effects on LV pump performance. NP raised cardiac index 35% (2.0 to 2.7 L/min/m2, p less than 0.005), whereas CPT increased this index 16% (1.9 to 2.2 L/min/m2, p less than 0.001). Concomitantly, the 31% elevation of stroke index produced by NP (26 to 34 ml/beat/m2, p less than 0.001) was greater (p less than 0.05) than the 15% rise produced by CPT (26 to 30 ml/beat/m2, p less than 0.001). Simultaneously, stroke work index showed similarly greater augmentation, and total systemic vascular resistance declined more with NP. These findings suggest that oral CPT is a predominant ventricular preload-lowering agent primarily likely to improve dyspnea related to severe pulmonary congestion in patients with advanced chronic CHF.

Complementary combined captopril and terbutaline therapy in severe chronic congestive heart failure

The hemodynamic effects of captopril (CPT) alone and in combination with the beta-adrenergic receptor agonist terbutaline (TBT) were evaluated in 10 patients with severe chronic congestive heart failure (CHF). The heart rate remained unchanged, while CPT lowered mean systemic blood pressure from 86 to 64 mm Hg (p less than 0.001) and decreased left ventricular filling pressure markedly from 27 to 19 mm Hg (p less than 0.001). The addition of TBT produced no further change in these variables (p greater than 0.05). Simultaneously, CPT augmented cardiac index (CI) from 2.1 to 2.9 L/min/m2 (p less than 0.001) and stroke index (SI) from 27 to 37 ml/beat/m2 (p less than 0.001). Concomitant CPT-TBT further raised CI to 3.2 L/min/m2 and SI to 40 ml/beat/m2 (both less than 0.001). Further, the CPT-effected decline in total systemic vascular resistance from 1577 to 841 dynes . sec . cm-5 (p less than 0.001) was not reduced additionally by CPT-TBT combination (p greater than 0.05). These results indicate than both CPT and TBT markedly augment cardiac function in CHF. Moreover, the salutary effects of the systemic vasodilator appear additive to the beneficial actions of the beta-adrenergic receptor agonist, thereby providing substantial augmentation of the function of the failing heart.

Hemodynamic effects of vasodilator therapy in severe left heart failure combined with large atrial septal defects

Two patients presented with severe left heart failure and large secundum atrial septal defects without severe pulmonary hypertension. The acute hemodynamic effects of two commonly used vasodilator agents, isosorbide dinitrate and hydralazine, are described. Although isosorbide dinitrate improved systemic forward cardiac output, it also increased left-to-right intracardiac shunting in both patients. On the other hand, hydralazine dramatically improved systemic toward output and concomitantly diminished left-to-right shunt flow in each patient (43 and 21 percent). The complexities of combined severe left ventricular failure and a large atrial septal defect with left-to-right shunting, and the importance of extensive hemodynamic monitoring at the time of pharmacologic intervention, are discussed.

Hemodynamic and radionuclide effects of acute captopril therapy for heart failure: changes in left and right ventricular volumes and function at rest and during exercise

Although the resting hemodynamic effects of captopril in congestive heart failure are known, little information is available about the hemodynamic response to captopril during exercise or about changes in noninvasive measurements of the size and function of both ventricles. In this study, 14 stable New York Heart Association class III patients were given 25 mg or oral captopril. Rest and exercise hemodynamic measurements and blood pool scintigrams were performed simultaneously before and 90 minutes after captopril. The radionuclide studies were analyzed for left and right ventricular end-diastolic volumes, end-systolic volumes, ejection fractions and pulmonary blood volume. The primary beneficial responses at rest were decreases in left and right ventricular end-diastolic volumes from 388 +/- 81 to 350 +/- 77 ml (p less than 0.01) and from 52 +/- 26 to 43 +/- 20 volume units (p less than 0.01), respectively, and in their corresponding filling pressures, from 24 +/- 10 to 17 +/- 9 mm Hg and 10 +/- 5 to 6 +/- 5 mm Hg (both p less than 0.001). Although stroke volume did not increase significantly, both left and right ventricular ejection fractions increased slightly, from 19 +/- 6% to 22 +/- 5% and from 25 +/- 9% to 29 +/- 11%, respectively (both p less than 0.01). During exercise, similar changes were noted in both hemodynamic and radionuclide indexes. Thus, in patients with moderate symptomatic limitation from chronic heart failure, captopril predominantly reduces ventricular volume and filling pressure, with a less significant effect on cardiac output. These effects persist during exercise, when systemic vascular resistance is already very low. Radionuclide techniques are valuable in assessing the drug effect in these subjects, particularly when ventricular volumes are also measured.

Long-term hemodynamic and clinical efficacy of captopril therapy in ambulatory management of severe chronic congestive heart failure

The 6-month extended vasodilator efficacy of the oral angiotensin converting enzyme (ACE) inhibitor, captopril (CPT), was evaluated by sequential cardiac catheterization, nuclear scintigraphy, echocardiography, treadmill exercise, and symptomatology in nine patients with severe chronic left ventricular (LV) failure (CHF). CPT lowered LV filling pressure (from 23 to 14 mm Hg acutely (p less than 0.001) and to 14 mm Hg (p less than 0.01) with continuous 6-month therapy; concomitantly CPT raised cardiac index from 2.03 to 2.46 L/min/m2 initially (p less than 0.02) and to 2.33 L/min/m2 (p less than 0.02) at 6 months. Simultaneously CPT raised LV ejection fraction from 0.21 to 0.25 acutely (p less than 0.01) and to 0.30 (p less than 0.001) and to 60 mm (p less than 0.001) at 6 months. These beneficial actions of CPT on LV pump function raised treadmill exercise duration (from 339 to 426 seconds initially (p less than 0.05) and to 499 seconds (p less than 0.05) at 6 months, while considerably reducing CHF symptomatology (p less than 0.001). Thus ACE inhibition by CPT provides markedly beneficial sustained hemodynamic and clinical improvement in advanced LV failure without fluid accumulation or late vasodilator drug tolerance.

Intravenous isosorbide dinitrate in patients with refractory pump failure and acute myocardial infarction

We studied the hemodynamic effects of isosorbide dinitrate administered by continuous i.v. infusion to 22 patients with chronic refractory pump failure and 18 with pump failure due to acute myocardial infarction. In patients with severe pump failure, i.v. ISDN markedly decreased pulmonary capillary wedge pressure (p less than 0.001), moderately increased cardiac output (p less than 0.01), and decreased systemic vascular resistance (SVR) (p less than 0.001). There were no deleterious effects on arterial pressure and heart rate. The effects obtained in acute and chronic left ventricular failure were similar. Patients with initial SVR levels lower than 1500 dyn-sec-cm-5 did not significantly increase their cardiac output (p less than 0.005). Cardiac output increased more than 25% only in patients with initial high SVR levels (greater than 2000 dyn-sec-cm(-)5). Positive correlations were found between high SVR and elevated plasma catecholamines (r = 0.53, p less than 0.05) and between the initial SVR and initial heart rate (r = 0.70, p less than 0.01). The i.v. administration of isosorbide dinitrate appears to be an efficient therapy, particularly in selected patients with ischemic pump failure.

Acute and long-term effects of captopril on exercise cardiac performance and exercise capacity in congestive heart failure

1 Although in many studies patients in heart failure treated with captopril have shown acute haemodynamic improvement at rest, little information is available about the haemodynamic response to captopril during exercise or about its effect on exercise tolerance.

2 Haemodynamic measurements were taken at rest and during upright bicycle exercise before and during the first two days of captopril treatment in 15 patients with stable congestive heart failure. At rest, the heart rate and mean arterial pressure both declined (84 ± 11 to 78 ± 7 beats/min (p < 0.25) and 85 ± 9 to 64 ± 8 torr (p < 0.001), the left ventricular filling pressure dropped dramatically (26 ± 9 to 15 ± 7 torr (p < 0.001) while cardiac and stroke indices rose (2.0 ± 0.5 to 2.5 ± 0.61/min/m² (p < 0.001) and 25 ± 8 to 33 ± 7 ml/min² (p < 0.001). Similar directional changes occurred during exercise, with heart rate, mean arterial pressure, and left ventricular filling pressure at maximum exercise all falling (123 ± 15 to 115 ± 16 beats/min (p < 0.01); 93 ± 17 to 86 ± 14 torr (p < 0.05); and 35 ± 10 to 30 ± 11 torr (p < 0.001) respectively). Maximum cardiac index rose slightly, from 3.6 ± 0.7 to 3.9 ± 0.6 l/min/m², acutely, but the change was not significant.

3 Six patients studied taking captopril long term underwent elective recatheterisation after 3 months. In these, either the beneficial haemodynamic changes seen with short-term treatment persisted or further improvement was noted, both at rest and during exercise. Most impressively, maximum exercise index rose from 3.6 ± 0.7 to 4.6 ± 1.01/min/m² (p < 0.05) and this was associated with an increase in exercise duration (8.0 ± 2.2 to 11.5 ± 1.4 minutes (p < 0.05), exercise work load (332 ± 32 to 468 ± 52 kilopond-metres min, (p < 0.05) and maximum oxygen consumption (11.8 ± 2.6 to 15.6 ± 2.7 ml/min/kg, (p < 0.05). These findings indicate that captopril is beneficial during activity as well as at rest and that chronic treatment increases exercise capacity.

Acute and long-term effects of vasodilator therapy on resting and exercise hemodynamics and exercise tolerance

The acute hemodynamic response to vasodilators in patients with chronic heart failure has been well characterized, but less is known about the long-term hemodynamic effects of vasodilator therapy. We measured hemodynamic variables at rest and during upright exercise in 11 patients during the initiation of therapy with oral hydralazine and sublingual isosorbide dinitrate and, in eight of these, after 3 months of continuous treatment. Marked initial increases in resting cardiac output and stroke volume and reductions in wedge pressure were sustained during chronic therapy. Similarly, the early improvement in exercise hemodynamic measurements persisted in most subjects. Exercise tolerance, quantified as the maximum duration of treadmill exercise, increased modestly (7.7 +/- 2.6 to 8.9 +/- 3.3 minutes, 0.05 less than p less than 0.10) after several days on vasodilators and further (10.2 +/- 3.7 minutes, p less than 0.01) during long-term treatment. The acute hemodynamic effects of vasodilator therapy at rest or during exercise did not correlate well with the changes in exercise tolerance. Our findings suggest that the combination of hydralazine and isosorbide dinitrate improves cardiac performance at rest and during exercise in patients with chronic heart failure and that this improvement persists during chronic therapy. In most patients, this hemodynamic improvement is accompanied by greater exercise tolerance.

Provocation of myocardial ischemic events during initiation of vasodilator therapy for severe chronic heart failure. Clinical and hemodynamic evaluation of 52 consecutive patients with ischemic cardiomyopathy

Although hydralazine provokes myocardial ischemic events in hypertensive patients not in heart failure by producing reflex tachycardia, the frequency of and mechanisms underlying ischemic events when this drug is administered as a vasodilator agent to patients with heart failure is unknown. The responses to hydralazine in 52 consecutive patients with severe chronic heart failure secondary to coronary artery disease were reviewed. Twelve patients (23 percent) had 16 ischemic events during the initial administration of hydralazine (angina at rest in 12 and myocardial infarction in 4); these generally occurred in the absence of significant tachycardia and hypotension. Thirty-five of the 52 patients received nitroprusside (8 of whom had ischemic events with hydralazine), but this drug provoked ischemia in only 1 of the 35 although it resulted in greater decreases in systemic arterial pressure than occurred with hydralazine. In patients with ischemic event only with hydralazine, left ventricular filling pressure decreased 14.6 mm Hg with nitroprusside but only 3.9 mm Hg with hydralazine (probability [p] less than 0.01). Provocation of ischemia with hydralazine may therefore be due to the relative preservation of elevated left ventricular preload with this drug, since ischemic events are not in common with nitroprusside despite greater decreases in systemic pressures.

Hemodynamic effects of prazosin in chronic heart failure

Three series of investigations were carried out with prazosin (PZN) hydrochloride. In the first, hemodynamic effects of PZN were compared with those of hydralazine (HDZ) in 11 patients with chronic congestive heart failure (CHF). In doses up to 5 mg, PZN increased cardiac output (CO) 20% accompanied by a 20% decrease in pulmonary capillary wedge pressure (LVFP). HDZ increased CO by 50% with little or no effect on LVFP. An additional 12 patients were given multiple 5 mg doses of PZN at 6-hour intervals with measurements of hemodynamic and plasma blood levels. Results suggested an attenuation of the effects of PZN on increasing CO but not on decreasing LVFP. This attenuation of CO was not due to inadequate plasma levels. Acute exercise studies (supine bicycle) were performed in 10 patients with severe CHF before and after the administration of several doses of PZN. There appeared to be a greater effect of PZN during exercise than at rest, with a beneficial increase in CO and reduction in LVFP. These data suggest that, despite hemodynamic attenuation of its effects on CO at rest, PZN may still be beneficial to active patients with CHF. In vitro studies with various vasodilators were performed to evaluate potential intropic effects. Isometric force (cat papillary muscle) increased 2% with 10-4M and 31% with 10-3M HDZ. PZN increased force 4% at 10-6M and 18% at 10-4M. Captopril did not increase force development at any dose level. The doses of HDZ and PZN that increased force development were higher than usual clinical doses.

Combined vasodilator and inotropic therapy of heart failure: experimental and clinical concepts

Vasodilators facilitate ventricular emptying by affording earlier onset of left ventricular (LV) ejection and increased stroke volume with achievement of a reduced end-systolic pressure and volume. Agents with positive inotropic properties increase stroke volume by shifting the end-systolic pressure-volume curve to the left through augmented force and velocity of contraction. With impedence reduction, improvement in pump performance occurs concomitant with reduced cardiac energy requirements (MVO2); positive inotropic agents most circumstances increase MVO2. The combination of a vasodilator and positive inotropic agent, as opposed to either alone, in the conscious animal shifts to the left and increases the slope of the LV end-systolic pressure-volume relation. Cardiac efficiency, defined by the slope of the relation between stroke volume and systolic tension, is increased by the combination of the drugs. In clinical heart failure, nitroprusside alone lowers LV preload with a modest increase in cardiac output (CO); dopamine markedly increases CO with little fall in LV preload. In combination the two agents achieve the individual beneficial effects of each drug, and cardiac efficiency indices are improved. Thus combined vasodilator and inotropic therapy appears to have a sound physiologic rationale and clinically documented beneficial effect superior to either modality alone.

Results of long-term vasodilator therapy in patients with refractory congestive heart failure

The long-term effects of vasodilator therapy with oral hydralazine and long-acting nitrates were studied in 34 patients with refractory heart failure. Seven patients who had marginal hemodynamic improvement despite optimal hydralazine therapy were not maintained on vasodilators, and eight who had a favorable hemodynamic response subsequently discontinued hydralazine therapy because of side effects. Of these 15 patients, four (27%) died and 11 remained in New York Heart Association functional class II or IV at a mean follow-up of 10 +/- 2 months (SEM). The 19 patients who received chronic therapy for 8 +/- 2 months were divided into nine late responders (47%), who improved to functional class I or II, and 10 late nonresponders (53%), who remained in functional class III or IV. Only one of the nine late responders (11%) died, compared with seven of the 10 late nonresponders (70%) (p less than 0.01). The actuarially determined survival at 1 year was 100% for late responders and 13 +/- 12% for late nonresponders (p less than 0.01). No clinical variable could distinguish late responders from late nonresponders. Hemodynamic variables measured before vasodilator therapy showed that late responders had a lower mean right atrial pressure (8 +/- 1 vs 17 +/- 3 mm Hg, p less than 0.01) and lower mean pulmonary artery wedge pressure (20 +/- 2 vs 30 +/- 2 mm Hg, p less than 0.005), higher stroke, volume index (27 +/- 2 vs 20 +/- 1 ml/m2, p less than 0.005) and higher stroke work index (32 +/- 4 vs 19 +/- 2 g-m/m2, p less than 0.01) than late nonresponders. There were no significant differences in the acute response to vasodilators between the two groups. We conclude that (1) a substantial portion of patients with refractory congestive heart failure either do not have a beneficial response to vasodilator therapy or discontinue it because of side effects; (2) about half of the patients who are maintained on chronic vasodilator therapy (or about one-fourth of the patients in whom therapy is initiated) had sustained clinical benefit; and (3) the initial hemodynamics, but not the clinical variables, are predictive of late mortality and late clinical response. Patients with evidence of more severe left ventricular dysfunction have an unfavorable course.

Comparison of the effects of dopamine, hydralazine, and isosorbide dinitrate on myocardial hemodynamics in patients with refractory heart failure

Nine patients with refractory congestive heart failure underwent hemodynamic study first with dopamine and then with oral hydralazine and sublingual isosorbide dinitrate. Although hemodynamic improvement was achieved with both forms of therapy, the beneficial effects of hydralazine alone or with isosorbide were superior to those of dopamine, as manifested by a greater reduction of wedge pressure and greater increase in stroke index. Six patients who demonstrated an increased wedge pressure during dopamine infusion were observed to manifest a louder apical systolic murmur and/or V wave in the wedge pressure tracing suggestive of enhanced mitral regurgitation. The rise in wedge pressure on dopamine could also be a consequence of increased myocardial ischemia and resultant decrease in ventricular compliance. It is possible that a subgroup of patients with heart failure are made worse by dopamine, and in these cases vasodilator therapy may be more beneficial.

Short- and long-term effects of hydralazine and combined hydralazine-prenalterol therapy in severe chronic congestive heart failure

The hemodynamic benefits of combined administration of prenalterol (P) with hydralazine (H) were evaluated in ten patients with severe chronic heart failure. Single administration of 100 mg H increased cardiac index (CI) from 2.3 to 3.0 l/min/m2, whereas pulmonary capillary wedge pressure (PWC) remained unchanged. After 3--4 weeks of treatment with 200 mg H hemodynamic improvementt was maintained (CI: 2.9 l/min/m2). Additional administration of P caused further augmentation of CI (3.3 l/min/m2). After long-term treatment with the combination of H and P sustained augmentation of CI (3.2 l/min/m2), and, furthermore, a slight but significant decrease of PCW were observed (p less than 0.05 vs. chronic single H-therapy). Five patients were able to perform exercise testing; H improved maximal exercise capacity and exercise hemodynamics in three patients. Further improvemen was observed after combined treatment (H + P) in three of five patients. It is concluded, the prenalterol may enhance the effectiveness of hydralazine therapy in congestive heart failure by providing concomitantly the principal actions of the vasodilator and positive inotropic agent used separately. Furthermore, the results indicate that oral long-term administration of hydralazine and prenalterol can produce sustained beneficial improvement.

Vasodilator treatment with isosorbide dinitrate and hydralazine in chronic heart failure

Several reports have suggested that because isosorbide dinitrate and hydralazine have different and additive haemodynamic effects at rest in patients with chronic heart failure, these agents should be administered in combination. Some studies, however, indicate thay they are effective individually as well. Since most patients with heart failure are symptomatic only with activity, we examined the haemodynamic effects of these drugs given individually and in combination, at rest and during upright bicycle exercise. As has been noted previously, at rest isosorbide significantly lowered both ventricular filling pressures and did not change cardiac output; hydralazine increased cardiac output and had only a slight effect on pulmonary capillary wedge pressure; combined treatment produced both beneficial effects. In contrast, during exercise isosorbide dinitrate also raised cardiac output while hydralazine more dramatically lowered the wedge pressure. Combined treatment produced significantly greater improvement in each haemodynamic index than either drug alone, with a resulting 54 per cent increase in exercise cardiac output, and a 33 per cent reduction in exercise wedge pressure. Maximal oxygen consumption increased acutely during combined treatment. These findings suggest that isosorbide dinitrate and hydralazine may each be effective in some patients, but that they are even more beneficial in combination.

Postural hypotension and tachycardia during hydralazine--isosorbide dinitrate therapy for chronic heart failure

Supine and upright hemodynamic measurements were performed in 10 patients with chronic congestive heart failure, before and during vasodilator therapy with hydralazine and isosorbide dinitrate. This combination of drugs produced significant improvement in supine hemodynamic measurements, with the pulmonary capillary wedge pressure decreasing from 26 +/- 5 to 18 +/- 5 mm Hg (mean +/- SD, p less than 0.01) and stroke volume index increasing from 25 +/- 6 to 39 +/- 6 ml/m2 (p less than 0.01), without any significant change in heart rate (HR) or mean arterial pressure (MAP). However, with the patients upright, HR rose significantly (87 +/- 17 to 99 +/- 17 beats/min, p less than 0.05) and MAP fell (84 +/- 10 to 66 +/- 11 mm Hg, p less than 0.001) compared with measurements before treatment. These patients also exhibited potentially deleterious postural changes in HR, MAP, cardiac output, stroke volume index and stroke work index during therapy with the combination of hydralazine and isosorbide dinitrate. Although diuretic therapy (which had been withheld for 12 hours in eight subjects but only for 6 hours in two others) may have played a role in producing these changes, postural hypotension or tachycardia was not noted before vasodilator therapy or during therapy with nitrates or hydralazine. Repeat catheterization after 3 months in six patients revealed a lessening of the postural effects. These findings indicate the need to perform upright as well as supine hemodynamic measurements during the initiation of vasodilator therapy and suggest the need for particular caution in patients with ischemic heart disease.

Long-term vasodilator therapy for heart failure: clinical response and its relationship to hemodynamic measurements

To assess the clinical efficacy of chronic vasodilator therapy for refractory congestive heart failure, the long-term follow-up (mean 13 months, range 3-30 months) was evaluated in 56 patients treated with hydralazine, usually in combination with nitrates. In the first 6 months, 73% improved subjectively and 59% improved by one or two New York Heart Association classifications; early improvement was usually sustained. Mortality was high, 22% at 6 months and 37% at 12 months, but was significantly lower in patients who had a clinical response to vasodilators (21% in responders vs 55% in nonresponders at 1 year). The only clinical indicator that differentiated responders from nonresponders was the presence or absence of symptomatic progression before initiation of vasodilator therapy. Pulmonary artery pressure, pulmonary capillary wedge (PCW) pressure and stroke work index (SWI) before and during vasodilator therapy correlated with clinical response and survival. Fifteen of 20 patients with PCW < 20 mm Hg and SWI greater than or equal to 30 g-m/m2 improved and survived, compared with two of 19 with PCS greater than or equal to 20 mm Hg and SWI < 30 g-m/m2. Patients who did not have acute hemodynamic improvement generally did not improve clinically, but neither the percentage change nor the absolute change in any hemodynamic variable predicted outcome in the remaining patients. The findings of this study indicate that vasodilators produce clinical improvement in many patients with refractory heart failure and that hemodynamic measurements are helpful in predicting the outcome of therapy.

Efficacy of oral angiotensin-converting enzyme inhibition with captopril therapy in severe chronic normotensive congestive heart failure

To evaluate the therapeutic efficacy of oral angiotensin-converting inhibition (ACE) with captopril in chronic normotensive congestive heart failure (CHF), acute and cardiocirculatory actions were determined by cardiac catheterization and forearm plethysmography, and ambulatory effects were assessed by echocardiography, nuclear angiography, treadmill exercise, and clinical symptomatology in 10 severe CHF patients. Captopril (90 mg) produced marked (peak 1 hour) and sustained (5 hours) left ventricular filling pressure (23 to 15 mm Hg), systemic vascular resistance decreases, and cardiac index increase (1.99 to 2.41 L/min/m2), while mean blood pressure declined mildly (87 to 80 mm Hg) without heart rate change. Both forearm venous tone and vascular resistance decreased considerably. After 1 week of ambulatory therapy (90 mg three times daily), nuclear angiographic ejection and echocardiogram shortening fractions increased, and exercise duration (341 to 453 sec) and New York Heart Association functional class (3.6 to 2.2) improved. Thus ACE-induced vasodilation by oral captopril improved cardiac performance and clinical status in refractory CHF.

Comparison of acute haemodynamic effects of nifedipine and isosorbide dinitrate in patients with heart failure following acute myocardial infarction

The acute haemodynamic effects of nifedipine (10 mg sublingually) and isosorbide dinitrate (5 mg sublingually) were compared in 13 patients with heart failure due to acute myocardial infarction. Nifedipine induced a significant reduction in systolic (from 122 +/- 5 to 107 +/- 3 mm Hg: mean +/- SEM; P less than 0.002) and diastolic blood pressure (from 85 +/- 3 to 75 +/- 2 mm Hg; P less than 0.01). Heart rate did not change significantly, nor did mean right atrial pressure. The mean pulmonary arterial pressure was lowered from 31 +/- 2 to 27 +/- 2 mm Hg (P less than 0.005). The left ventricular filling pressure decreased from 24 +/- 1 to 19 +/- 1 mm Hg (P less than 0.0001). A significant increase in cardiac index (from 2.33 +/- 0.13 to 2.69 +/- 0.15 l/min per m2; P less than 0.001) and in stroke volume index (from 24 +/- 2 to 28 +/- 2 ml/beats per m2; P less than 0.005) was registered. Systemic vascular resistance fell from 1742 +/- 145 to 1308 +/- 85 dynes/sec per cm-5 (P less than 0.00005). After isosorbide dinitrate was administered a significant reduction in mean right atrial pressure (from 9.5 +/- 1.6 to 5.1 +/- 1.2 mm Hg; P less than 0.0001), in mean pulmonary arterial pressure (from 32 +/- 1 to 23 +/- 1 mm Hg; P less than 0.00001) and in left ventricular filling pressure (from 23 +/- 1 to 16 +/- 1 mm Hg; P less than 0.0001) was seen. No significant change in systolic and diastolic blood pressure, heart rate, cardiac index, stroke volume index and systemic vascular resistance was registered. No side-effects were seen after nifedipine and isosorbide dinitrate were administered.

Hydralazine and isosorbide dinitrate: comparative central and regional hemodynamic effects when administered alone or in combination

Central and regional hemodynamic studies were performed before and after the oral administration of 75 mg of hydralazine and/or 20 mg of isosorbide dinitrate in 15 patients with low-output congestive heart failure. Hydralazine increased mean cardiac output 17-25%, mean renal blood flow 19%, and limb blood flow 17% (all p < 0.05). Mean hepatic blood flow did not change significantly with hydralazine. Except for a small increase in cardiac output (6%, p < 0.05) at 30 minutes, isosorbide dinitrate did not significantly alter central, renal, hepatic or limb blood flow. Combining isosorbide dinitrate and hydralazine effected similar increases in cardiac output (17-24%, p < 0.05), renal (17%, p < 0.05) and limb (20%, p < 0.05) blood flow as those elicited by hydralazine alone. The combination did not significantly alter mean hepatic blood flow. Hydralazine, alone or combined with isosorbide dinitrate, increases renal and limb blood flow in congestive heart failure in proportion to the augmented cardiac output; isosorbide dinitrate alone does not alter blood flow to these regions. Neither drug (or combination) changes hepatic blood flow in this clinical setting.

Importance of left ventricular chamber size in determining the response to hydralazine in severe chronic heart failure

To examine the importance of left ventricular chamber size in determing the response to vasodilator therapy, we performed echocardiography in 40 patients with chronic refractory heart failure before they were treated with oral hydralazine. The left ventricular end-diastolic dimension (LVEDD) correlated significantly with the per cent change in stroke volume (r = 0.77), left ventricular filling pressure (r = -0.68), and stroke work index (r = 0.87) during short-term drug administration. After 14 to 21 days of maintenance therapy, 15 of 24 patients with an LVEDD greater than or equal to 60 mm were improved, and one was worse; mean blood urea nitrogen decreased from 45.6 to 30.6 mg per deciliter in the 21 patients in this group who completed the study (16.3 to 10.9 mmol per liter) (P less than 0.001). In contrast, only two of 16 patients with an LVEDD less than 60 mm improved, whereas 10 showed clinical deterioration; blood urea nitrogen increased from 49.3 to 64.2 mg per deciliter in the 13 patients in this group who completed the study (17.6 to 22.9 mmol per liter) (P less than 0.01). These findings indicate that left ventricular chamber size is an important factor in the response to hydralazine in patients with severe chronic heart failure.

Beneficial effects of hydralazine on rest and exercise hemodynamics in patients with chronic severe aortic insufficiency

We studied the effects of afterload reduction in chronic severe aortic insufficiency by measuring the hemodynamic response to oral hydralazine in 10 consecutive patients. Hemodynamics were also measured during maximal exercise in eight of these patients. At rest, hydralazine reduced pulmonary artery wedge pressure from 14 to 9 mm Hg (p less than 0.01), and increased cardiac index by 70% and stroke volume index by 35% (both p less than 0.001). Before hydralazine, pulmonary artery wedge pressure exceeded 20 mm Hg in five patients during maximal exercise; with hydralazine, at identical levels of exercise, pulmonary artery wedge pressure remained below 20 mm Hg in all patients. For the group, hydralazine reduced pulmonary artery wedge pressure from 21 to 12 mm Hg (p less than 0.05) and increased cardiac index by 31% (p less than 0.05) during exercise; changes in stroke volume index were more variable and there was no significant increase for the group, although several patients increased stroke volume substantially and the overall increase was 34%. These data show that afterload reduction has beneficial effects on cardiac performance in chronic severe aortic insufficiency both at rest and during exercise. Hydralazine may be of use in such patients either in preparation for valve replacement or as interim therapy.

Immediate and sustained hemodynamic and clinical improvement in chronic heart failure by an oral angiotensin-converting enzyme inhibitor

The hemodynamic effects of an oral angiotensin-converting enzyme inhibitor, captopril, were evaluated in 10 symptomatic patients with chronic congestive heart failure. In all patients there was a significant increase in cardiac output (average 28%), stroke volume (49%), and stroke work index (26%), along with a decrease in pulmonary capillary wedge pressure (48%), indicating improved left ventricular function. Modest decreases in heart rate and arterial pressure were also observed. In seven patients maintained on captopril therapy, repeat hemodynamic studies at 2 months revealed sustained effects. These beneficial hemodynamic effects were accompanied by clinical improvement and improved exercise tolerance during maintenance therapy. These findings suggest that captopril may be a useful therapeutic adjunct for the long-term management of patients with chronic congestive heart failure.