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Biomedical subjects

M A Frais

Publications and source records attributed to M A Frais.

At least 37 records · Page 2Linked to original sources
PubMed1986

Comparative effects of metoprolol and celiprolol on cardiac hemodynamics and left ventricular volume at rest and during exercise-induced angina.

Celiprolol is a cardioselective beta-adrenoceptor antagonist with attributed cardiostimulant properties. Its hemodynamic profile was compared in a dose-response study with that of metoprolol, which is also cardioselective but lacks cardiostimulatory activity. In 24 patients with angiographically proved coronary artery disease, simultaneous hemodynamic and left ventricular ejection fraction (EF) values were determined at rest in the control (drug-free) state and repeated 3 to 5 minutes after each of four intravenous boluses of celiprolol, 1, 1, 2, and 4 mg, or equivalent beta-blocking doses of metoprolol, 1.25, 1.25, 2.5, and 5.0 mg. The effects of each drug on hemodynamics during exercise-induced angina were determined by exercise testing in the control state and after the maximum cumulative dose of each drug. At rest, metoprolol reduced heart rate, cardiac index, and the left ventricular EF and increased pulmonary artery occluded pressure (PAOP), systemic vascular resistance, and left ventricular end-systolic and end-diastolic volumes. Celiprolol increased cardiac and stroke volume indices and the EF; the PAOP was reduced without change in other measured variables. During exercise, metoprolol significantly increased the PAOP, which was unchanged by celiprolol. At exercise both drugs reduced cardiac index and heart rate, but neither altered the EF. The cardiac function curve demonstrated greater depression at rest after metoprolol than after celiprolol; these differences were attenuated during dynamic exercise. The lesser adverse impact of celiprolol on cardiac function may be attributable to ancillary cardiac stimulatory properties offsetting the cardiac depression after beta-adrenoceptor blockade.

Angina Pectoris↗
PubMed1986

Haemodynamic dose-response effects of intravenous indoramin in acute heart failure complicating myocardial infarction.

The haemodynamic dose-response effects of intravenous indoramin were evaluated in 12 patients with acute heart failure (pulmonary artery occluded pressure of greater than 20 mm Hg) complicating a recent myocardial infarction. Following a 1-h control period with confirmed stable haemodynamics, the effects of three intravenous bolus doses of indoramin (0.125, 0.125, and 0.25 mg/kg at 15-min intervals) were determined in the 10- to 15-min period following each intravenous injection. Plasma drug concentrations rose with the administered dose and were in the previously established therapeutic range. Ten patients tolerated all three doses of the drug; two patients were withdrawn following the second dose owing to clinically evident hypotension (systolic blood pressure of less than 100 mm Hg). Indoramin resulted in progressive falls in systolic, diastolic, and mean systemic arterial pressures (p less than 0.01) without change in cardiac index. There was a dose-related reduction in the heart rate (0.5 mg/kg; -7 beats/min; p less than 0.01). The left ventricular filling pressure showed a significant and quadratic reduction over the dose range (0.5 mg/kg, -5 mm Hg; p less than 0.01). The systemic vascular resistance index was reduced (-333 dynes X s X cm-5 X m2; p less than 0.001) and the stroke volume index increased (+3 ml/m2; p less than 0.05) following the maximum cumulative dosage. These data established the therapeutic safety of indoramin (0.125-0.5 mg/kg) in acute heart failure following myocardial infarction. An improvement in cardiac performance in these patients was compatible with circulatory actions on both cardiac preload and afterload.

Acute Disease↗
PubMed1986

Differential actions of atenolol and celiprolol on cardiac performance in ischemic heart disease.

The therapeutic relevance of differences between beta-adrenoceptor antagonists, related to their ancillary pharmacological properties, is debated. Celiprolol is a novel cardioselective beta-blocking agent with attributed cardio-stimulating properties. Its hemodynamic profile was compared with that of atenolol (cardioselective; no ISA) in a comparative dose-response study of 24 patients with angiographically documented coronary artery disease. Following a stable control period four i.v. boluses of equivalent beta-blocking doses of atenolol (1, 1, 2, and 4 mg) or celiprolol (1, 1, 2, and 4 mg) were administered, and hemodynamics and left ventricular ejection fraction were determined. The comparative actions of the two drugs on the hemodynamics of exercise-induced angina were compared by exercise testing in the control state and following the maximum cumulative dose of each drug. At rest, atenolol reduced heart rate, cardiac index, and left ventricular ejection fraction (EF); systemic vascular resistance index increased without change in systemic arterial or pulmonary artery occluded pressures. Celiprolol increased cardiac index and ejection fraction without change in other variables. During exercise both drugs reduced cardiac index and heart rate; neither altered the exercise EF. The cardiac function curve, relating cardiac index to left ventricular end-diastolic pressure, was significantly depressed by atenolol but was elevated at rest by celiprolol. Thus these studies demonstrated hemodynamic differences between atenolol and celiprolol, presumably related to the ancillary properties of the latter. The relevance of such differences to the therapy of patients with coronary artery disease deserves further examination.

Adrenergic beta-Antagonists↗
PubMed1986

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.

Adrenergic beta-Antagonists↗
PubMed1986

Comparative haemodynamic effects of intravenous lignocaine, disopyramide and flecainide in uncomplicated acute myocardial infarction.

A prospective study evaluated the comparative haemodynamic effects of three Class I antiarrhythmics (lignocaine Class 1B, disopyramide Class 1A and flecainide Class 1C) in 30 patients with uncomplicated acute myocardial infarction. Three groups, each of 10 patients, were allocated to lignocaine (Group I) 1.5 mg kg-1 i.v. loading dose over 10 min followed by infusion at 3 mg kg-1 h-1, disopyramide (Group II) or flecainide (Group III), both administered as a 1.0 mg kg-1 i.v. loading bolus over 10 min followed by a 1.6 mg kg-1 h-1 infusion for 120 min. The plasma levels of each drug were in the described therapeutic range. Lignocaine decreased cardiac index (-0.3 l min-1 m-2 (9%); P less than 0.05) and stroke volume index (-5 ml m-2 (11%); P less than 0.01). Systemic blood pressure, heart rate and systemic vascular resistance index were unchanged. There was a small increase (+3 mm Hg (30%); P less than 0.01) in pulmonary artery occluded pressure (PAOP). Both disopyramide and flecainide increased systemic blood pressure; the maximum increases for mean blood pressure were +10 mm Hg (11%) and +4 mm Hg (4%) respectively. Both drugs reduced cardiac index (-0.5 l min-1 m-2 (16%): -0.4 l min-1 m-2 (11%)) and stroke volume index (-11 ml m-2 (25%): -5 ml m-2 (11%)). There were increases in heart rate (+13: +5 beats min-1) pulmonary artery occluded pressure (+2: +3 mm Hg) and systemic vascular resistance index (+696: +275 dyn s cm-5 m2).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

A haemodynamic dose finding study with a new slow-calcium channel blocker (amlodipine) in coronary artery disease.

The haemodynamic dose-response effects of a new long-acting slow-calcium channel blocking agent, amlodipine were evaluated in 20 patients with angiographically confirmed coronary heart disease. At rest, following a control saline period, four i.v. doses of the drug (cumulative dosage 1.25, 2.5, 5 and 10 mg) were administered to ten patients and haemodynamics determined in the ten to 15 minutes following injection. Effects on circulatory parameters were only evident following the maximum cumulative dosage. Accordingly in a further ten patients, the regimen was doubled (cumulative i.v. dosage 2.5, 5, 10 and 20 mg). In each study the haemodynamic effects during constant load supine bicycle exercise were evaluated by comparison of values during the control exercise period and following the final cumulative dosage. On the higher regimen, amlodipine significantly reduced resting systolic, diastolic and mean (p less than 0.01) systemic arterial pressure and systemic vascular resistance index (p less than 0.01). Heart rate (p less than 0.01), stroke volume index (p less than 0.01) and cardiac index (p less than 0.01) increased; pulmonary artery occluded pressure was unchanged. During constant load bicycle exercise, the mean arterial pressure was significantly reduced (p less than 0.01), and the heart rate and cardiac index increased (p less than 0.01). Thus the immediate impact of amlodipine in stable coronary artery disease was to reduce left ventricular afterload and augment cardiac pumping performance. The minimum effective i.v. dosage appeared to be 10 mg. Amlodipine appears sufficiently promising to warrant longer-term studies in ischaemic heart disease.

Adult↗
PubMed1986

Nuclear cardiology techniques in the assessment of ischemic heart disease.

Invasive techniques of cardiac catheterization and angiography have become the gold standard for the diagnosis and management of patients with ischemic heart disease. More recently there has been a remarkable development of noninvasive imaging techniques which has resulted in improved ability to select patients in need of invasive investigations and in a more complete understanding of the physiological and clinical significance of information obtained from such invasive investigations. The value and limitations of the 3 most common techniques, radionuclide ventriculography, myocardial perfusion scintigraphy and acute myocardial infarction scintigraphy, are discussed in this review in relation to the assessment of patients with proven or suspected ischemic heart disease. These nuclear cardiology techniques are now available in most hospitals with nuclear medicine equipment; a good understanding of the strengths and weaknesses of each technique is essential for optimal clinical use.

Angiocardiography↗
PubMed1985

The effects on left ventricular performance of verapamil and metoprolol singly and together in exercise-induced angina pectoris.

Concurrent therapy with the calcium channel blocker, verapamil, and the beta-blocking group of compounds is usually felt to be clinically contraindicated due to the former's potent dromotropic and negative inotropic actions. The basis of this assumption was examined in a rest and exercise hemodynamic study of the effects of verapamil and the cardioselective beta-blocking drug, metoprolol, in 22 patients with stable angina pectoris and angiographically confirmed coronary artery disease. In a randomized study, 11 patients were assessed following intravenous verapamil (16 mg) alone, 11 following intravenous metoprolol (10 mg) alone, and all 22 were assessed on combination therapy. The plasma levels achieved at the time of each hemodynamic assessment were in the therapeutic range. At rest, verapamil alone significantly lowered systemic arterial pressure and vascular resistance; metoprolol alone lowered heart rate and increased systemic vascular resistance without change in systemic arterial pressure. Combination therapy reduced systemic arterial pressure and heart rate without change in cardiac output and systemic vascular resistance. During upright bicycle exercise, the changes were directionally similar. Depression of cardiac function (i.e., reduced cardiac output at increased pulmonary artery occluded pressure) occurred following metoprolol but not following verapamil; the addition of verapamil did not accentuate the depression of function induced by metoprolol. These results suggested that in patients with stable coronary artery disease, without manifest conduction system abnormality, the cardiac depressant actions of verapamil were countered by its vasodilator properties.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

Hemodynamic dose-response effects of flecainide in acute myocardial infarction with and without left ventricular decompensation.

We evaluated the hemodynamic effects of the class I antiarrhythmic flecainide in 20 patients within 18 hours of an acute myocardial infarction. Equal numbers of patients with normal (group 1) or decompensated (group 2) ventricular function were studied. Both groups received flecainide, 1 mg/kg, as an intravenous bolus over 10 minutes, followed by infusion (1.6 mg/kg/hr) over the next 120 minutes. Plasma concentrations increased linearly with the cumulative flecainide dosage in both groups. There was no difference between the groups in the plasma levels reached, which were within the recognized antiarrhythmic range for flecainide (200 to 1000 ng/ml) throughout the infusion. The hemodynamic effects of flecainide for each group were decreases in systolic blood pressure (maximum 3% fall in group 1 and 8% fall in group 2), cardiac index (9% fall in group 1 and 18% fall in group 2), stroke volume index (13% fall in group 1 and 23% fall in group 2), stroke work index (14% fall in group 1 and 27% fall in group 2), with an increased heart rate (8% rise in group 1 and 5% rise in group 2), pulmonary artery occluded pressure (27% rise in group 1 and 21% rise in group 2), and systemic vascular resistance (11% rise in group 1 and 18% rise in group 2). Diastolic and mean arterial blood pressures did not change. Our data demonstrate that flecainide induced significant cardiodepression in both groups of patients. These effects were not significantly greater in patients with adequately controlled heart failure. These data suggest that the mild negative inotropic properties of flecainide in patients with recent myocardial infarction are comparable to those described for other class I antiarrhythmics.

Adult↗
PubMed1985

Haemodynamic analysis of the effects of nicardipine and metoprolol alone and in combination in coronary artery disease.

The circulatory consequences of concurrent slow-calcium channel (nicardipine) and cardioselective beta blockade (metoprolol) were evaluated in 20 patients with angiographically proven coronary artery disease. The rest and exercise haemodynamic impact of intravenous nicardipine (10 mg) or metoprolol (10 mg) alone was determined by randomly allocating 10 patients to each drug; finally all patients were assessed on combination therapy. The plasma levels of nicardipine (17 +/- 3 to 53 +/- 6 ng ml-1) and metoprolol (36 +/- 5 to 97 +/- 16 ng ml-1) achieved at the time of each study were in the established therapeutic range. At rest nicardipine reduced systemic mean arterial pressure and systemic vascular resistance index; cardiac and stroke volume indices increased without change in pulmonary artery occluded pressure. Metoprolol alone reduced systemic blood pressure, heart rate and cardiac index, and increased systemic vascular resistance index. Combination therapy reduced systemic arterial blood pressure and heart rate with relatively modest effects on cardiac index, systemic vascular resistance index and pulmonary artery occluded pressure. During dynamic exercise nicardipine reduced systemic mean and diastolic arterial pressure and stroke work index without change in other haemodynamic variables. Metoprolol reduced exercise systemic arterial pressures, heart rate and cardiac index, and increased systemic vascular resistance index and pulmonary artery occluded pressure. Combination therapy produced changes similar to those at rest; at peak nicardipine pharmacodynamic activity, the cardiac depressant actions of metoprolol were largely offset by the induced reduction in left ventricular afterload.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

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.

Adult↗
PubMed1985

Haemodynamic dose-response effects of intravenous nisoldipine in coronary artery disease.

The circulatory consequences of slow-calcium channel blockade with a new dihydropyridine nisoldipine were evaluated at rest and during exercise-induced angina in 16 patients with angiographically proven coronary artery disease. In 10 patients resting cardiac stroke output (thermodilution) and pulmonary artery occluded pressure were determined following four intravenous nisoldipine injections (cumulative dosage of 1, 2, 4 and 8 micrograms kg-1). The exercise effects of nisoldipine were evaluated by comparing the effects of the 8 micrograms kg-1 cumulative dosage with a control exercise period at the same workload. At rest nisoldipine reduced systemic vascular resistance and mean arterial pressure, and increased heart rate, cardiac and stroke volume indices. During 4 min supine-bicycle exercise nisoldipine reduced systemic mean arterial pressure and vascular resistance; this resulted in augmented cardiac and stroke volume indices at an unchanged pulmonary artery occluded pressure. In six additional patients rest and exercise ejection fractions were measured using a nonimaging nuclear probe. Nisoldipine (4 micrograms kg-1) resulted in a small trend to increase left ventricular rest and exercise ejection fraction. These data demonstrated improved rest and exercise cardiac performance following nisoldipine in patients with severe coronary artery disease.

Adult↗
PubMed1985

Anti-hypertensive dose-response effects of nicardipine in stable essential hypertension.

The dose-response effects of oral nicardipine on the systemic blood pressure were examined in 54 patients with uncomplicated essential hypertension (DBP greater than or equal to 100 mm Hg). The study was designed in four sequential stages. A 2 week single-blind placebo run-in period was followed by dose titration with nicardipine at 2 week intervals. Patients achieving the target DBP less than or equal to 95 mm Hg were then crossed over to placebo for 2 weeks, following which the previous dose of nicardipine was readministered for 6 weeks. Forty-eight patients completed the dose-titration phase. The target DBP 95 mm Hg was achieved in 33; in eight after 10 mg three times daily, in 21 after 20 mg three times daily, in three after 30 mg three times daily and in one after 40 mg three times daily. In the 48 patients, systolic blood pressure was reduced from 188 +/- 25 to 158 +/- 21 mm Hg (P less than 0.001) and diastolic blood pressure from 111 +/- 9 to 93 +/- 13 mm Hg (P less than 0.001); heart rate increased from 81 +/- 7 to 87 +/- 13 beats min-1 (P less than 0.01). Thirty-one of the 33 patients completed the crossover to placebo, which was accompanied by a significant increase towards pretreatment blood pressure levels. Reinstitution of nicardipine at the previous dose resulted in a reduction of SBP and DBP to levels not significantly different from those at the end of the dose-titration stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

A study of the long-term efficacy and tolerability of oral nicardipine in hypertensive patients.

This study was designed to evaluate the efficacy of oral nicardipine in 91 patients with uncomplicated essential hypertension over a period of 12 months. All patients started on a fixed nicardipine dose of 30 mg three times daily which was adjusted in the range 10-40 mg three times daily, where necessary to achieve a target diastolic blood pressure less than 95 mm Hg. At 6 weeks, blood pressure (mean +/- s.e. mean) was reduced from an average of 190 +/- 22/112 +/- 8 to 167 +/- 23/96 +/- 11 mm Hg supine and from 180 +/- 21/113 +/- 7 to 154 +/- 17/95 +/- 11 mm Hg standing and remained controlled in all patients throughout the study. A total of 96 unwanted experiences were reported by 49 patients (54%); 17 (19%) reported a single symptom once and two (2%) reported a single symptom more than once. The most frequently reported adverse experiences were peripheral oedema in 27 (28%) and headaches in 15 patients (16%). The majority of the adverse experiences occurred in the first 3 months of treatment. Ten patients (11%) withdrew from the study during this time and eight (9%) in the subsequent 9 months because of drug-related side effects; five others (5%) withdrew for unrelated reasons. The incidence of adverse experiences was dose-related. Three patients reported unwanted effects on 10 mg three times daily, eight on 20 mg three times daily, 36 on 30 mg three times daily, and 12 on 40 mg three times daily oral nicardipine.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1985

Effects of nicardipine on cardiac volume at rest and during exercise-induced angina.

The action of nicardipine on cardiac volume, both at rest and during exercise-induced angina, was evaluated in 12 patients with angiographically-proven coronary artery disease. Nicardipine given to patients at rest reduced systemic vascular resistance and mean arterial pressure and increased heart rate and cardiac index. The left ventricular filling pressure, ejection fraction (EF), end-diastolic and end-systolic volumes were unchanged. During supine bicycle exercise, the reduction in systemic arterial blood pressure following nicardipine increased cardiac and stroke index and attenuated the rise in left ventricular filling pressure observed in the control exercise. The effects of nicardipine on EF, end-diastolic and end-systolic cardiac volumes were dependent on the baseline cardiac reserve. In patients with EF less than 50%, nicardipine improved EF and left ventricular exercise volumes.

Adrenergic beta-Antagonists↗
PubMed1985

Assessment of pericardial constraint in dogs.

To determine the better method of measuring pericardial constraint, pericardial pressure was recorded by a liquid-filled open-ended catheter and a liquid-containing flat balloon in six open-chest anesthetized dogs. Left ventricular pressure was measured by a micromanometer-tipped catheter and left ventricular anteroposterior diameter was measured by sonomicrometry. Left ventricular end-diastolic pressure was raised to 20 +/- 1.7 (mean +/- SD) mm Hg by intravenous saline. Left ventricular diastolic pressure-diameter loops were constructed (1) with incremental amounts of saline (0 to 50 ml) in the resealed pericardium, (2) with several small holes in the pericardium, and (3) with the pericardium widely open. Measured pericardial pressures were compared with what was assumed to be the correct pericardial pressure, i.e., the calculated difference between left ventricular diastolic pressure (at a given left ventricular diameter) before and after opening the pericardium. Pressure recorded by the flat balloon was similar to the calculated pericardial pressure at all pericardial liquid volumes. Pressure recorded by the open-ended catheter, however, was significantly lower (p less than .05) than the calculated pressure unless there was at least 30 ml of liquid in the pericardium. After several holes had been made in the pericardium it still exerted a constraining effect, as shown by a marked rightward or downward shift of the left ventricular diastolic pressure-diameter relationships after completely opening the pericardium. After holes were made in the pericardium pressure recorded by the flat balloon was still similar to the calculated pericardial pressure. However, pressure recorded by the open-ended catheter was significantly (p less than .02) lower than the calculated pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗