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Biomedical subjects

V Legrand

Publications and source records attributed to V Legrand.

At least 91 records · Page 5Linked to original sources

Hemodynamic effects of intravenous diltiazem with impaired left ventricular function.

The acute hemodynamic effects of intravenous diltiazem were studied in 8 patients with coronary artery disease, left ventricular (LV) failure (New York Heart Association functional class III), a rest ejection fraction (EF) less than 40% or a cardiac index less than 2.4 liters/min/m2. Hemodynamic measurements and LV angiograms were performed at rest before and after the administration of diltiazem, 0.5 mg/kg, administered at a speed of 5 mg/min. Diltiazem treatment induced a decrease in heart rate from 68 +/- 12 to 55 +/- 9 beats/min (p less than 0.001). Mean aortic pressure decreased from 94 +/- 14 to 81 +/- 15 mmHg (p less than 0.05). Thus, the pressure-rate product significantly decreased under the influence of the drug, from 8,791 +/- 2,465 to 6,342 +/- 1,808 beats mm Hg/min, (p less than 0.001). Diltiazem induced no significant change of LV end-diastolic pressure, pulmonary wedge pressure, cardiac index and LV stroke work index. Systemic vascular resistance decreased (p less than 0.01), whereas pulmonary vascular resistance showed no change. End-systolic volume diminished (p less than 0.02), which accounts for the increase of stroke volume and ejection fraction (p less than 0.001). Disorders of regional contractility were not aggravated by diltiazem, and even improved in individual cases. Thus, intravenous diltiazem may be used safely in patients with heart failure. However, in view of the marked bradycardic effects seen in some cases, heart rate should be carefully monitored.

Adult↗

Haemodynamic effects of intravenous diltiazem at rest and exercise in patients with coronary artery disease.

The acute effects of intravenous diltiazem on exercise performance were studied in 10 patients with coronary artery disease. Haemodynamic measurements were made at rest and during exercise before and after 0.5 mg kg-1 of diltiazem. Diltiazem prolonged the duration of exercise (+2.85 min, P less than 0.001) and delayed the onset of ischaemic ST depression or angina in all patients. The highest tolerated heart rate and pressure rate product were increased in all but one patient after diltiazem. At rest diltiazem decreased mean arterial pressure (-10.8%, P less than 0.005), systemic vascular resistance (SVR) (-11.8%, P less than 0.05) and left ventricular stroke work index (SWI) (-14.1%, P less than 0.005). During exercise under diltiazem therapy, at the level achieved before the drug, the pulmonary capillary wedge pressure (-30%, P less than 0.005) and the SVR (-13.6%, P less than 0.02) were lowered, the SWI (+13%, P less than 0.01) was increased; at the end of exercise only the SVR (-14%, P less than 0.05) was reduced. Two patients experienced angina on lying down and one had orthostatic hypotension after exercise with diltiazem. This study indicates that intravenous diltiazem is a potentially useful agent for the treatment of angina by reducing myocardial oxygen demand at rest and by improving left ventricular performances on exercise.

Adult↗

Hemodynamic effects of a new antiarrhythmic agent, flecainide (R-818), in coronary heart disease.

The hemodynamic effects of flecainide acetate, a new class I antiarrhythmic agent, were studied in 10 patients with coronary heart disease. The drug was injected intravenously at a dose of 2 mg/kg over 30 minutes. The mean drug plasma level achieved was 394 ng/ml (range 329 to 470). The heart rate did not change, but a significant increase (p less than 0.001) in P-R (+17%), QRS (+15%), and Q-T (+7%) duration occurred after drug administration. Negative inotropic effects also were observed and consisted of an increase (p less than 0.01) in pulmonary wedge pressure (+27%) and a decrease (p less than 0.01) in stroke index (-10%), left ventricular stroke work index (-12%), and left ventricular ejection rate (-11%). No significant change in mean aortic pressure or systemic and pulmonary vascular resistance occurred. Left ventriculography performed after drug infusion revealed a significant increase (p less than 0.01) in systolic volume (+9%) and a decrease in ejection fraction (-9%) and mean velocity of circumferential fiber shortening (Vcf) (-13%). A progressive and significant decrease of dP/dt was observed during drug infusion, but 15 minutes after the injection, dP/dt had returned to near basal values. Thus, flecainide acetate has slight, but significant negative inotropic effects, particularly conspicuous during drug infusion. The drug should be administered with caution in patients with poorly compensated heart.

Adult↗

Right ventricular myocardial infarction diagnosed by 99 m technetium pyrophosphate scintigraphy: clinical course and follow-up.

Out of 178 consecutive patients with acute inferior wall myocardial infarction submitted to technetium-99 m pyrophosphate scintigraphy, 49 (27.5%) were found to have concomitant right ventricular infarction. Gated blood pool scans showed right ventricular abnormalities in 21 out of 26 patients who were submitted to this investigation (right ventricular asynergy: 16 cases; right ventricular dilatation: eight cases; decreased right ventricular ejection fraction: 16 cases). Complications were common in the acute stage. Shock was noted in 19 cases (eight related to bradycardia, three related to relative hypovolaemia and eight instances of true cardiogenic shock). Atrial fibrillation (seven patients), ventricular fibrillation (eight patients) and severe atrioventricular conduction disorders (13 patients) were also frequent. In spite of this, the in-hospital mortality was low: three deaths occurred (6.1%), one from heart failure, two others from posterior septal rupture. All patients were followed up for one year or more. Six additional deaths were noted (three from left cardiac failure, two from recurrent anterior wall infarction and one from massive pulmonary embolism). Clinical assessment, haemodynamic measurements and gated blood pool scans showed significant improvement of right ventricular function with return to normal in those cases with small right ventricular infarcts as judged from technetium-99 m pyrophosphate scintigraphy. In spite of the complications seen in the initial period, patients with a right ventricular infarction have a good overall prognosis and the long-term outcome, primarily determined by the left-sided lesions, is often favourable.

Adult↗

Evaluation of right-ventricular function by gated blood-pool scintigraphy.

The purpose of this paper is to review several modalities that can be helpful in evaluating right-ventricular (RV) function. We have investigated the role of functional imaging in analysis of regional RV function and in selection of RV region of interest (ROI). From this we have derived a method to determine the RV ejection fraction using a single RV ROI. The analysis is performed in a modified LAO projection; Fourier phase and amplitude functional images are used to help trace the ROI and study wall-motion abnormalities. This method is compared with the double-ROI technique of Maddahi. Values of RV ejection fraction obtained with one ROI correlate well with those obtained using two ROIs (r = 0.95). The regression equation is used to correct for the single-ROI underestimation. The inter- and intra-observer variability is better for the single- than for the double-ROI technique. RV function studies are performed in normal volunteers and in patients with a variety of cardiac disorders. Changes in RV ejection fraction caused either by direct alteration of RV function or by altered loading conditions are documented. Analysis of regional RV function demonstrates RV free wall as well as septal perturbations, further characterizing the extent of dysfunction and providing some etiologic information. We conclude that: 1. RV ejection fraction can be measured by the use of an adequate single diastolic ROI; and 2. A simple equilibrium gated technique can provide detailed information about global and regional RV function that should be systematically added to the analysis of the parameters for left-ventricular function.

Adolescent↗

Patients with myocardial infarction and normal coronary arteriogram.

Eighteen patients who survived an acute myocardial infarction were found to have a normal coronary arteriogram. Seven patients were younger than 35 years and six were female. The myocardial infarction was nontransmural in 11 cases. The mean follow-up was 21.6 months. Eleven patients developed residual chest pain at rest early after myocardial infarction. One, treated by beta-blockers, suffered a recurrent myocardial infarction. Eight became asymptomatic, and two improved under antispastic therapy. Another patient developed a severe form of variant angina three months after myocardial infarction; she died following plexectomy. Finally, two patients experienced rare episodes of angina at rest. The stress ECG was negative in all cases. Provocative test for spasm was positive in three out of nine patients. Diffuse narrowing associated with chest pain was demostrated in two patients at angiography. Thus, myocardial infarction and subsequent normal coronary angiogram are mainly found in young female patients, and infarction is often nontransmural. Clinical evidence of vasospastic phenomena and increased vasomotor tone are found in most patients. Whenever residual chest pain is controlled by antispastic therapy, the follow-up course seems benign.

Adult↗

Prognostic significance of electrocardiographic findings in angina at rest. Therapeutic implications.

Ninety-five patients with angina at rest were observed in the coronary care unit. Eighty-one per cent presented concomitantly or had previously presented some other manifestations of coronary artery disease. These patients were divided into two subgroups. In subgroup 1 (40 patients), episodes of non-exertional angina were associated with a pattern of hyperacute subepicardial injury and, frequently, with ventricular arrhythmias. In subgroup 2 (55 patients), the episodes of angina at rest were attended by horizontal ST depression, isolated T wave inversion, or trivial ST-T changes. Coronary angiographic findings were similar in both subgroups. Symptoms regressed in only 9% of patients in subgroup 1 while they were receiving beta-receptor antagonists, whereas amiodarone alone or amiodarone with nifedipine was successful in 58%. Of these patients, 25% developed a myocardial infarction shortly after admission. In subgroup 2 patients, beta-blockers were successful in 61%. Amiodarone isolated or associated with nifedipine was successful in 55% of the patients in whom it was tried. Only 5% of patients in this subgroup developed a myocardial infarction during their hospital stay. It is concluded that: (1) observation of the electrocardiogram during spontaneous angina in patients with known atherosclerotic coronary heart disease may be of prognostic significance and may influence therapeutic decision. (2) Amiodarone by virtue of its anginal and antiarrhythmic properties may be particularly useful in the treatment of non-exertional angina.

Adrenergic beta-Antagonists↗

Prognostic value of thallium-201 stress myocardial scintigraphy with exercise ECG after myocardial infarction.

The prognostic value of stress electrocardiogram and thallium-201 stress myocardial scintigraphy was analyzed in 224 patients 3 months after a myocardial infarction; both techniques allowed an adequate stratification based on the presence of ST depression or multivessel disease. Combining stress electrocardiogram and stress myocardial scintigraphy data improved the prognostic ability, particularly in patients who associated multivessel disease and ST depression.

Aged↗

Premature opening of the pulmonary valve in right ventricular myocardial infarction.

An echocardiogram performed in a patient with a large right ventricular infarction reveals a premature opening of the posterior leaflet of the pulmonic valve. This opening appears initiated by the atrial contraction and its clinical and pathophysiological significance is discussed. We conclude that perturbations of the pulmonary valvular motion can occur during right ventricular infarction and reflect a profound alteration in phasic right ventricular flow.

Diastole↗

Combined mexiletine and amiodarone treatment of refractory recurrent ventricular tachycardia.

A combined mexiletine and amiodarone treatment was applied in nine cases with recurrent refractory ventricular tachycardia. During the first two days of treatment, mexiletine and amiodarone were perfused intravenously at a dose of 1,000 mg. and 1,500 mg. per 24 hours, respectively. Simultaneously amiodarone was also given orally at a dose of 600 mg. per 24 hours. From the third day onwards, the intravenous administration was interrupted and both drugs were continued orally at a dose of 600 mg. daily. The first three patients were very critically ill and had had at least five episodes of ventricular tachycardia per 24 hours during the last 10 days in the intensive care unit. The treatment resulted in total suppression of the tachycardic episodes within three days after initiation of therapy. In the remaining six cases, ventricular tachycardia was easily initiated by programmed electrical stimulation of the heart. No arrhythmia could be elicited by repeated testing on the seventh day of treatment. The mean follow-up period was 6 months. Two patients with poor left ventricular function died in intractable heart failure. Another one died suddenly 4-1/2 months after his release from the hospital. He had a large aneurysm and whether he continued his treatment is unknown. A fourth patient had an aneurysmectomy; he suffered a recurrence, and died at his second operation. All the others presently remain asymptomatic. The association of a class I (mexiletine) with a class III (amiodarone) agent is theoretically attractive for the treatment of refractory ventricular arrhythmias. The present findings corroborate this hypothesis, but show that this association is not able to protect individuals with severe underlying myocardial damage.

Adult↗