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Biomedical subjects

C V Leier

Publications and source records attributed to C V Leier.

At least 145 records · Page 8Linked to original sources
PubMed1983

Human myocardial histologic characteristics in congestive heart failure.

The purpose of this study was to identify the histologic characteristics of human myocardium in congestive heart failure (CHF) by cellular hypertrophy, nuclear area, endocardial thickness, and percentage of fibrosis and to correlate histologic findings to cause, severity, and duration of disease. Right ventricular endomyocardial biopsies from 109 patients were quantitatively analyzed. Ten patients with normal cardiac history, physical examination results, and cardiac function served as the control group. The remaining patients were divided into the following groups: those treated with doxorubicin (n = 18), and those with chest pain with normal coronary arteries (n = 8), familial CHF (n = 3), CHF associated with myotonic dystrophy (n = 3), peripartal CHF (n = 2), valvular CHF (n = 9), alcohol-induced CHF (n = 13), postviral CHF (n = 6), or idiopathic CHF (n = 36). Linear regression analyses showed a strong correlation between cell diameter and nuclear area (r = .70, p less than .001) and weaker correlations between amount of fibrosis and cell diameter (r = .30, p less than .005) and fibrosis and nuclear area (r = .29, p less than .005). Results of function studies and histologic measurements (e.g., echocardiographically measured change in the minor-axis dimension of the left ventricle with systole and cell diameter) correlated poorly (r = -.33, p less than .005). Duration of dyspnea did not correlate with any histologic factor. Within the normal group there was a direct correlation of cell diameter with age (r = .67, p less than .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Biopsy↗
PubMed1983

Postoperative pericarditis following thymectomy for myasthenia gravis. A prospective study.

Eight consecutive patients who underwent thymectomy for the treatment of myasthenia gravis were evaluated prospectively for the development of postoperative pericarditis. In four of the eight patients (50 percent) pericarditis developed within 48 hours after thymectomy. All four had a three-component pericardial friction rub, two of the four patients had a new postoperative pericardial effusion by echocardiography, and in two typical ECG diffuse concave ST segment elevation and evolutionary ST and T wave changes developed. In the four patients with postoperative pericarditis, a malignant thymoma adherent to the pericardium was found in two, while two patients had a normal thymus histology with no adherence to the pericardium. Thus, postoperative pericarditis was found in both of the patients with a thymoma and in two of six patients without a thymoma. This study demonstrates that a high incidence of pericarditis occurs following thymectomy for the treatment of myasthenia gravis.

Adolescent↗
PubMed1983

Drugs five years later. Dobutamine.

Dobutamine is a synthetic catecholamine developed as a relatively selective positive inotropic drug for short-term parenteral administration. Dobutamine's effects are mediated by strong beta 1 adrenergic receptor stimulation and mild stimulation of beta 2 and alpha 1 receptors. Dobutamine should be used to improve ventricular function and cardiac performance in patients in whom ventricular dysfunction has caused a reduced stroke volume and cardiac output, a mild to moderate drop in systemic blood pressure, diminished organ and tissue perfusion, and elevated ventricular filling pressures. When guidelines for patient selection and dosing are adhered to, ventricular dysfunction and cardiac decompensation secondary to atherosclerotic occlusive coronary artery disease can be improved without adversely affecting the myocardial oxygen supply and demand balance. Dobutamine has less vasopressor activity than norepinephrine and dopamine, and should not be the primary treatment in conditions characterized by marked hypotension and shock.

Animals↗
PubMed1983

Attempt to prevent doxorubicin-induced acute human myocardial morphologic damage with acetylcysteine.

Doxorubicin induced acute as well as chronic myocardial morphologic alterations. Twenty patients with normal cardiovascular function were randomized to 2 groups based on age and dose of doxorubicin. Group I received placebo 1 hour before doxorubicin administration; group II received acetylcysteine (N-acetyl-L-cysteine) (Nac) 1 hour before doxorubicin. Endomyocardial biopsies were performed at base line at 4 and 24 hours after doxorubicin administration. Biopsy tissue was viewed by electron microscopy, and stereoscopic techniques were used to determine tubular and mitochondrial area. The change of the tubular area was similar in the 2 groups, was maximum at 4 hours, and was proportionately spread throughout the cell. The mitochondrial swelling was also similar in the 2 groups and proportionate throughout the cell but was maximum at 24 hours. This study demonstrated that the acute doxorubicin-induced damage was diffuse and not prevented by Nac.

Acetylcysteine↗
PubMed1983

Acute and chronic isosorbide dinitrate therapy in congestive heart failure: demonstration of improved exercise capacity and differing arterial and venous tolerance during chronic administration.

Thirty patients with congestive heart failure underwent a double-blind study after randomization into either isosorbide dinitrate or placebo. The initial dose (40 mg orally) of isosorbide dinitrate reduced resting and exercise pulmonary artery, pulmonary capillary wedge, and systemic blood pressure and pulmonary and systemic vascular resistance without improving exercise tolerance. Chronic dosing (40 mg orally every 6 h for 3 months) increased exercise tolerance and maintained a reduction in resting and exercise pulmonary artery and pulmonary capillary wedge pressures and pulmonary resistance, while systemic pressure and resistance returned to baseline. Chronic oral isosorbide dinitrate (40 mg every 6 h) improves exercise capacity over a 3-month period with disparate tolerance effects on systemic arterial, systemic venous, and pulmonary vasculature.

Heart Failure↗
PubMed1983

Heart rate responsiveness after sustained chronotropic stimulation with a beta 1-adrenergic receptor agonist.

Six normal male human subjects underwent two 72 hr infusions of saline (control) and butopamine, a beta-adrenergic agonist with strong positive chronotropic properties, in order to determine the chronotropic responsiveness of the human heart after sustained chronotropic stimulation. Chronotropic responsiveness was assessed by heart rate responses to intravenous isoproterenol and bicycle ergometry before and serially over 50 hr after discontinuation of the infusions. Chronotropic responsiveness to isoproterenol and exercise was reduced significantly in the butopamine group compared to control; this blunted chronotropic effect persisted beyond 48 hr. Positive inotropic responsiveness, assessed by echocardiography and systolic time intervals, was reduced modestly for the butopamine-treated group up to 24 hr after infusion. Although the precise mechanisms are not fully elucidated, continuous chronotropic stimulation of the human heart with the beta 1 agonist, butopamine, elicits a significant reduction in the heart rate response to isoproterenol and exercise challenges. In addition, the degree and time course of suppression of the chronotropic vs. inotropic responsiveness are disparate.

2-Hydroxyphenethylamine↗
PubMed1982

Cardiac function in Duchenne's muscular dystrophy. Results of 10-year follow-up study and noninvasive tests.

The purposes of this study were to: (1) evaluate the progression of cardiac involvement in Duchenne's muscular dystrophy using systolic time intervals (PEP/LVET); (2) determine if the degree of cardiac involvement bears a relation to the severity of skeletal muscle disease; and (3) describe the M-mode and two-dimensional echocardiographic findings. In 1970, systolic time intervals were studied in 16 patients. During the 10-year interim, two patients were lost to follow-up study, and five patients died. Nine remaining patients were re-studied in 1980 with M-mode and two-dimensional echocardiography as well as systolic time intervals. The PEP/LVET value of these nine patients increased from 0.37 +/- 0.05 (mean +/- SD) in 1970 to 0.47 +/- 0.07 (p less than 0.005) in 1980. Three patients remained ambulatory, and their PEP/LVET value (0.41 +/- 0.04) was significantly better than that of the nonambulatory patients (0.50 +/- 0.07, p less than 0.05). The M-mode echocardiography percentage diameter change was also worse in the nonambulatory group (21 +/- 4 percent versus 34 +/- 7 percent, p less than 0.02). The five patients who were nonambulatory in 1970 died in the intervening 10 years. This study demonstrated that the heart disease of Duchenne's muscular dystrophy is progressive and that the severity of skeletal muscle disease is probably associated with the degree of cardiac dysfunction.

Adolescent↗
PubMed1982

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.

Blood Pressure↗
PubMed1982

Intravenous isosorbide dinitrate in the management of acute hypertension following cardiopulmonary bypass.

Twenty-one patients with acute systemic hypertension following cardiopulmonary bypass received isosorbide dinitrate intravenously in order to determine its effectiveness in managing this postoperative problem. Twenty patients underwent coronary artery bypass operation, and 1 patient had a pulmonary valvotomy. Bolus administration (0.25 to 2.5 mg [3.0 to 40.0 micrograms per kilograms]) decreased systemic systolic blood pressure 23% and diastolic blood pressure 25% (both, p less than 0.01). Continuous controlled infusion (0.125 to 0.332 mg per minute [1.5 to 6.0 micrograms/kg/min]) caused a more modest drop in systemic blood pressure, with a 17% reduction in systolic blood pressure and an 11% drop in diastolic blood pressure (both, p less than 0.05). Additional pressure reduction and maintenance therapy were provided by intermittent bolus administration or a continuous infusion. Moderate venodilation (decrease in central venous pressure) accompanied the systemic pressure response. The heart rate was not appreciably altered and, with exception of 1 patient in whom systemic pressures were reduced to 105/60 mm Hg after bolus infusion, the desired level of systolic, diastolic, and mean arterial pressures were readily titrated and maintained in a stable, predictable manner. These observations suggest that intravenously administered isosorbide dinitrate is a practical, safe, and highly effective method of treatment of hypertension following cardiopulmonary bypass.

Acute Disease↗
PubMed1982

Intravenous pirbuterol.

Pirbuterol was given intravenously to nine normal men to determine the hemodynamic effects of intravenous injection of this rather selective beta 2-adrenoceptor agonist. Pirbuterol induced marked improvement of the echocardiographic (percent change in the dimension of the minor axis of the left ventricle during systole, ejection fraction, and velocity of left ventricular circumferential fiber shortening) and systolic time interval (preejection period interval, preejection period/left ventricular ejection time) indices of ventricular performance. The increase in stroke volume was indicated by elevation of systolic blood pressure and widening of pulse pressure. Vascular beta 2-receptor agonist effects were indicated by the fall in diastolic and mean systemic blood pressure and marked reduction in derived systemic vascular resistance. Dose-related positive chronotropic properties were observed without dysrhythmias. There was a good direct correlation between mean plasma pirbuterol concentration and dose. Because of the reported efficacy of oral doses, the direct relationship between plasma concentration and dosage, the positive inotropic properties, and the peripheral vasodilating effects of pirbuterol, investigation of the intravenous form of the drug in patients with severe decompensated low-output congestive heart failure seems warranted.

Adult↗
PubMed1982

The anatomic relationship of the esophageal lead to the left atrium.

This study was undertaken to establish the "in vivo" anatomic relationship of the esophageal catheter to the left atrium. Fourteen patients, seven of whom had enlarged left atria, were included in the study. During cardiac catheterization, a bipolar recording catheter was placed in the esophagus; left atrial cineangiograms were then obtained in the posterior-anterior (PA), left anterior oblique (LAO), and lateral views. The distance of the esophageal catheter, in each of four commonly used positions, to the interatrial septum-right atrium was measured in the PA and LAO cineangiograms. The distance from the same catheter positions to the posterior left atrial wall was measured from the lateral view. In all positions and regardless of left atrial size, the catheter clearly lay behind the left atrium and was closer to the left atrial wall than any other cardiac structure, including the interatrial septum. Bipolar electrograms were recorded from the four commonly used esophageal locations; atrial wave amplitude and other parameters of the electrogram deflection did not vary significantly in the different lead positions. We conclude that esophageal electrograms reflect left atrial activity by virtue of the recording electrode's clear proximity to this structure. The amplitude and configuration of the atrial wave itself is generally not useful in determining the position of the esophageal lead.

Adult↗
PubMed1982

Effects of hydralazine on coronary blood flow and myocardial energetics in congestive heart failure.

The acute effects of oral hydralazine, 1 mg/kg, on coronary vascular resistance, coronary blood flow (estimated using the coronary sinus thermodilution technique), and myocardial oxygen consumption were evaluated in 10 patients with chronic (New York Heart Association class III and IV) nonischemic congestive heart failure. Central hemodynamic responses demonstrated a modest decrease in mean arterial pressure, pulmonary capillary wedge pressure and systemic vascular resistance (12%, 15% and 29%, respectively), while the cardiac index increased from 2.3 +/- 0.1 to 3.1 +/- 0.3 and left ventricular stroke work index from 24 +/- 3.7 to 28 +/- 3.4 (p less than 0.01). Heart rate and diastolic filling time did not change. Coronary blood flow increased approximately 50%, from 144 +/- 17 to 218 +/- 30 ml/min, and coronary vascular resistance decreased from 0.55 +/- 0.09 to 0.36 +/- 0.08 mm Hg/ml/min (both p less than 0.01). Oral hydralazine increased myocardial oxygen consumption by 33%, from 15 +/- 1.6 to 20 +/- 2.7 ml/min. Despite this moderate augmentation in myocardial oxygen consumption, the arterial-coronary sinus oxygen difference decreased from 104 +/- 6.2 to 94 +/- 7.5 and the myocardial oxygen extraction ratio decreased from 71% to 64% (both p less than 0.05). The ratio of coronary vascular resistance to systemic vascular resistance decreased with hydralazine therapy, while coronary blood flow increased from 3.5% to 4.3 % of total cardiac output. In this group of patients with nonischemic cardiomyopathy, hydralazine had a favorable effect on the coronary circulation and improved the critical myocardial oxygen supply-demand ratio.

Adult↗
PubMed1982

Drug-induced conditioning in congestive heart failure.

Continuous 72-hour infusions of dobutamine reportedly effect sustained clinical improvement in patients with congestive heart failure. This study was designed to determine if shorter, more frequent infusions, delivered in an outpatient setting, elicit a similar response. Twenty-six patients with moderately severe congestive heart failure were randomized, 11 into a control group and 15 into a dobutamine treatment group. Baseline data were collected for 4 weeks in each group. Thereafter, the dobutamine treatment group received 4-hour infusions of dobutamine weekly for 24 weeks. Systolic time intervals, echocardiography, cardiac index and treadmill exercise tolerance were used to follow the progress of the control and dobutamine treatment groups. The ratio of preejection period to left ventricular ejection time and the cardiac index did not change significantly in either group. The velocity of circumferential fiber shortening and the percent change in the minor axis of the left ventricle during systole improved modestly (p less than 0.05) above baseline in the dobutamine group after 14 weeks of treatment and above the corresponding control values (p less than 0.05) after 22 weeks. Exercise tolerance (duration) improved 25--51% (all p less than 0.05) above baseline in the dobutamine group compared with 10--17% (all p greater than 0.05 vs baseline) in the control group. Heart rate at maximal exercise did not change significantly from baseline for either group and did not differ significantly between the two groups. Functional classification improved in 12 of 15 dobutamine treatment patients and in only two of 11 control patients (p less than 0.05). In our patients with congestive heart failure, weekly 4-hour dobutamine infusions did not elicit a major change in resting left ventricular function; however, exercise performance and clinical status improved considerably.

Adult↗
PubMed1982

The effect of vasodilator therapy on systolic and diastolic time intervals in congestive heart failure.

To determine the effects of vasodilator drugs on systolic and diastolic time intervals in patients with congestive heart failure, these noninvasive measurements were made in 50 patients with moderately severe disease before and after vasodilator therapy. These data were compared with direct hemodynamic measurements obtained simultaneously from a flow-directed triple-lumen pulmonary artery catheter placed in each patient. Oral vasodilators included isosorbide dinitrate 20 mg (n-8), hydralazine 75 mg (n-8), and 100 mg (n-8), and first-dose prazosin 2 mg (n-8) and 5 mg (n-8). Ten additional patients received intravenous dose-response infusions of isosorbide dinitrate, nitroglycerin, and nitroprusside. Increases in cardiac output and stroke volume effected a decrease (improvement) in the systolic time interval parameter of ventricular performance, PEP/LVET. The correlation coefficient for vasodilator-induced changes in cardiac output vs changes in PEP/LVET was -0.82 (P less than 0.05) and for changes in stroke volume and PEP/LVET was -0.75 (P less than 0.05). In general, the diastolic time period was not significantly affected by these drugs. The systolic time intervals are a simple and useful method for evaluation of vasodilator therapy in patients with congestive heart failure.

Administration, Oral↗