Effects of propranolol and nitroglycerin on left ventricular performance in patients with coronary arterial disease

Pharmacodynamic monitoring during acute intervention in ischaemic heart disease using a new echo-Doppler device

1. We have utilised a new non-imaging echo-Doppler cardiac output device, using the principle of attenuated compensated volume flow (ACVF), to assess the cardiovascular effects of atenolol and buccal nitroglycerin (NTG) in a placebo-controlled study of 30 patients with coronary disease. 2. Atenolol (4 mg i.v.) reduced heart rate, cardiac output and time-averaged mean aortic velocity (P less than 0.01) and increased systemic vascular resistance (P less than 0.01). 3. Buccal NTG (5 mg) reduced systemic mean arterial pressure (P less than 0.01), cardiac stroke volume (P less than 0.05) and stroke length (P less than 0.01). 4. Thus although both drugs reduced time-averaged aortic velocity (an index of cardiac performance), the concomitant reduction in cardiac stroke length and tachycardia suggested sub-optimal cardiac filling for buccal NTG, whereas for atenolol (with the associated increased systemic vascular resistance but unchanged stroke length) attenuation of sympathetic stimulation at cardiac beta-adrenoceptors. 5. The ACVF method of cardiovascular monitoring should prove useful in human pharmacodynamic studies.

Effects of nicorandil on left ventricular hemodynamics and volume at rest and during exercise-induced angina pectoris

The hemodynamic effects of nicorandil (20 mg) were compared with placebo in a double-blind study of 20 patients with angiographically proved coronary artery disease at rest before and 7, 15, 30 and 60 minutes after oral dosing. The impact of the drug on left ventricular (LV) hemodynamics and volume during exercise-induced angina was determined by repeating exercise 60 minutes after drug administration, at the same work load that reliably induced angina during control predrug exercise. At rest, nicorandil reduced all components of systemic arterial pressure without change in cardiac or stroke volume indexes or heart rate. Pulmonary artery occluded pressure was reduced without change in LV ejection fraction or systemic vascular resistance index. Effects were evident at 7 minutes and peaked at 30 minutes with attenuation at 60 minutes. Compared with control supine bicycle exercise, the drug (at 60 minutes) reduced mean systemic arterial pressure and LV filling pressure without change in cardiac stroke volume indexes and heart rate. There was a smaller increase in LV ejection fraction. These data suggested greatest impact on LV function during exercise when substantial decreases in filling pressure occurred at maintained cardiac pumping indexes.

A rest and exercise haemodynamic evaluation of a new cardio-selective beta-adrenoceptor blocker celiprolol alone and in combination with nitroglycerine in ischaemic heart disease

The symptomatic benefits of combining beta-adrenoceptor blockers and nitrates in angina pectoris are well recognised. Their actions on cardiac haemodynamics and volumes when combined have been poorly characterized. Accordingly this study investigated a new cardioselective beta-adrenoceptor blocking agent celiprolol and buccal nitroglycerine in 24 patients with angiographically documented coronary artery disease. Following a control period, with confirmed stable haemodynamics, three groups (n = 8/group) of prospectively matched patients, were studied following intravenous celiprolol (8 mg), buccal nitrate (10 mg) or their combination. Haemodynamics and left ventricular ejection fraction (nuclear probe) were determined following each intervention. The actions of each regimen on the haemodynamics of exercise-induced angina were compared by exercise testing in the control state and following each regimen. At rest, celiprolol did not alter haemodynamic parameters. Nitrate therapy reduced left ventricular filling pressure (pulmonary artery occluded pressure--PAOP) and volumes; the ejection fraction and heart rate increased. Combination therapy resulted in a highly significant reduction in left ventricular preload and afterload (PAOP and mean arterial blood pressure) at an increased left ventricular ejection fraction and reduced cardiac volumes; there was a trend to reduce cardiac double product (HR X SBP). During exercise celiprolol reduced systolic blood pressure, heart rate and cardiac index; systemic vascular resistance index increased. Nitrate therapy reduced blood pressure and PAOP, and increased ejection fraction. Combination therapy reduced all components of the triple product (heart rate, systolic blood pressure and PAOP) without affecting the other haemodynamic or radionuclide parameters. These data suggest improvements in cardiac function from the combination of celiprolol and nitrate therapy which were not achieved by either agent when used as monotherapy; they afford an interesting insight into the manner in which such widely utilised therapeutic modalities interact in coronary artery disease.

Acute hemodynamic effects of propranolol, glycerylnitrate, and exercise in coronary patients with left ventricular dysfunction

Some adverse effects of beta-blockers in heart failure are counteracted by glycerylnitrate. However, the hemodynamics in this condition after giving both drugs are not well known. We examined the drug combination in exercising coronary patients with left ventricular dysfunction. Elevated left ventricular end-diastolic pressure was a measure of dysfunction. A right-heart catheterization with three successive exercise stress tests was done in 40 patients. At repeated exercise without drugs a "warming up" phenomenon was observed, consisting of small but statistically significant reductions in pulmonary capillary wedge pressure, and heart rate. At exercise propranolol reduced heart rate, cardiac output, systemic blood pressure, left ventricular work, and increased arteriovenous oxygen difference. Glycerylnitrate reduced pulmonary capillary wedge pressure at exercise, but, contrary to the findings at rest, it did not increase heart rate or reduce cardiac output. The drug combination resulted in hemodynamics that were similar to those after propranolol alone, except for a lower pulmonary capillary wedge pressure. The drug combination allowed the patients to exercise with the benefits of the beta-blocker, but at a lower ventricular filling pressure. Thus, the potential hazard of giving beta-blockers to patients with left ventricular dysfunction may be reduced by adding glycerylnitrate.

Effects of buccal nitrate on left ventricular haemodynamics and volume at rest and during exercise-induced angina

A novel approach has been employed to characterize the effects of a cardioactive drug on left ventricular haemodynamics and volume by simultaneously determining cardiac stroke volume (thermodilution) and left ventricular ejection fraction (nuclear probe). The effects of glyceryl trinitrate were evaluated in 12 patients with angiographically proven coronary artery disease at rest and 3, 7, 15 and 30 min following 10 mg buccal nitroglycerin (Suscard) administration. The impact of the drug on left ventricular haemodynamics and volume during exercise-induced angina was determined by repeating exercise 30 min following drug administration, at the workload that reliably induced angina during control exercise. At rest buccal nitroglycerin reduced systemic arterial pressure, cardiac and stroke volume indices, and increased heart rate. The left ventricular ejection fraction (E.F.) increased; its filling pressure together with end-diastolic and end-systolic volumes were significantly reduced. Compared with control supine-bicycle exercise, the drug reduced mean systemic arterial pressure and left ventricular filling pressure without change in cardiac and stroke volume indices. There was a smaller increase in left ventricular volume during exercise, and the fall in E.F. was attenuated. These data demonstrated differential actions of glyceryl trinitrate on left ventricular function related to the physiological state in obstructive coronary artery disease. These techniques appear to hold promise in the evaluation of the effects of other therapies on left ventricular volume in coronary artery disease.

Selection of optimal drug therapy for the patient with angina pectoris

The development of new drugs, especially beta-blocking and calcium entry-blocking agents, has greatly facilitated the medical treatment of angina pectoris. The specific needs of each patient should dictate the appropriate treatment of angina pectoris. Angina may occur in patients who have various concomitant disorders such as hypertension, diabetes mellitus, peripheral vascular disease, chronic obstructive pulmonary disease, or arrhythmias, and the physician must take these factors into account when a drug regimen is prescribed. Individual drugs should be chosen on the basis of specifically desired pharmacologic effects, and the dosages should be gradually adjusted according to the patient's response. Although a therapeutic regimen should be selected primarily on the basis of efficacy, the physician must also attempt to recommend a simple and cost-effective program.

"Maximal" drug therapy is not necessarily optimal in chronic angina pectoris

Beta-adrenergic blocking agents, nitrates and calcium channel antagonists are effective in treating angina pectoris, but much remains unknown about how they act in combination. Consequently, treadmill exercise was used to assess the relative efficacy of nifedipine or isosorbide dinitrate, or both, in 19 patients with stable angina receiving propranolol. Propranolol therapy was continued and either placebo, nifedipine (20 mg), isosorbide dinitrate (20 mg) or both drugs were given randomly 1 1/2 hours before exercise in a double-blind trial. In 16 patients who completed the protocol, heart rate at rest during propranolol therapy was 53.7 +/- 1.9 beats/min (mean +/- standard error of the mean); it increased 4.6 +/- 1.2 beats/min with the addition of nifedipine (p less than 0.01), but was unchanged with isosorbide dinitrate or both combined. Compared with values during treatment with propranolol alone, systolic blood pressure at rest decreased with each vasodilator individually and when combined. Rate-pressure product at maximal exercise was the same with all combinations. Exercise duration was 467 +/- 50 seconds with propranolol, increased to 556 +/- 47 seconds with isosorbide dinitrate (p less than 0.05) and to 636 +/- 50 seconds with nifedipine (p less than 0.001). Exercise duration with all three drugs was 597 +/- 47 seconds (p less than 0.01 compared with propranolol alone). The improvement with nifedipine was greater than with isosorbide dinitrate (p less than 0.05) but exercise duration was not significantly different with the combination of these drugs than when either drug was used alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Reversal of regional myocardial depressant effects of propranolol with nitroglycerin

Use of propranolol in acute myocardial infarction is limited by its cardiodepressant effects. The effects of nitroglycerin (0.4 mg intravenously) on regional myocardial dysfunction produced by total or partial (50 percent) coronary occlusion and intravenous administration of propranolol (1.0 mg/kg) were evaluated using pairs of ultrasonic crystals implanted subendocardially in the nonischemic and ischemic zones in 14 open chest dogs. During partial coronary occlusion, systolic shortening (% delta L) in the ischemic zone decreased from 20.9 +/- 5.3 to 7.2 +/- 6.4 (p less than 0.001). Propranolol did not change it significantly. Nitroglycerin increased % delta L from 6.7 +/- 4.5 to 11.2 +/- 5.3 (p less than 0.01). The nonischemic zone was unaffected by partial coronary occlusion but showed a decrease in % delta L from 18.6 +/- 6.2 to 15.6 +/- 5.1 (p less than 0.01) with propranolol. Nitroglycerin increased % delta L from 15.6 +/- 5.1 to 17.3 +/- 5.9 (p less than 0.02). During total coronary occlusion, nitroglycerin administration after propranolol improved % delta L in the nonischemic but not in the ischemic zone. Nitroglycerin caused a significant decrease in left ventricular systolic and end-diastolic pressures. Heart rate remained unchanged. It is concluded that nitroglycerin reversed myocardial depressant effects of propranolol in both the partially ischemic and the nonischemic zones after acute coronary occlusion.

Favorable effects of acebutolol on exercise performance and angina in men with coronary artery disease

Acebutolol, a relatively cardioselective beta-adrenergic blocking drug, was administered to 20 men with coronary artery disease and angina. A three month double-blind cross-over (placebo and acebutolol) design was used following a 12-week placebo phase and a six-week dose-titration phase. During the cross-over phase, acebutolol (400 mg in 19 men and 300 mg in one, orally three times per day) increased the duration of treadmill exercise (placebo, 6.8 +/- 0.5) min [average +/- SEM]; acebutolol, 8.1 +/- 0.6 min; P less than 0.05) and decreased the frequency of ST segment depression during exercise (placebo, 12 or 20 men; acebutolol, 6 of 20 men). The heart rate x systolic blood pressure product (x 10(-2)) was decreased both at rest (placebo, 105.0 +/- 4.0; acebutolol, 84.0 +/- 3.0; P less than 0.01) and during exercise (placebo, 199.0 +/- 10.0; acebutolol, 144.0 +/- 8.0; P less than 0.01). Acebutolol treatment decreased the frequency of angina (diary cards) (placebo, 9.0 +/- 2.4 episodes per week; acebutolol, 6.4 +/- 2.2 episodes per week; P less than 0.05) and decreased the consumption of nitroglycerin (placebo, 9.0 +/- 4.4 tablets per week; acebutolol, 7.4 +/- 4.0 tablets per week; P less than 0.05). Results suggest that acebutolol increases exercise performance and decreases the occurrence of angina in men with coronary disease.