Biomedical subjects

T De Marco

Publications and source records attributed to T De Marco.

24 records · Page 2Linked to original sources

PubMed1988

Dopexamine hydrochloride in chronic congestive heart failure with improved cardiac performance without increased metabolic cost.

Dopexamine hydrochloride is a new intravenous, short-acting agent with agonist activity at beta 2-adrenergic and DA1-dopaminergic receptors. The effects of dopexamine hydrochloride infusion on systemic and coronary hemodynamics, myocardial metabolism and the neuroendocrine system were evaluated in 10 patients with chronic severe congestive heart failure at baseline, at rates of 1, 2, 4 and 6 micrograms/kg/min at 15-minute intervals, and after a 1-hour infusion of the "optimal" dose. Right atrial pressure was reduced by 25% (p less than 0.01), pulmonary capillary wedge pressure by 26% (p less than 0.05), systemic vascular resistance by 44% (p less than 0.001) and pulmonary vascular resistance by 34% (p less than 0.01) after the optimal dose. Heart rate increased by 17% (p less than 0.01), rate-pressure product by 17% (p less than 0.01) and stroke volume index by 31% (p less than 0.001). There was no change in mean arterial pressure, myocardial oxygen consumption, coronary sinus blood flow, myocardial oxygen extraction or norepinephrine balance. None of the patients demonstrated net myocardial lactate production. These findings suggest that dopexamine hydrochloride improves systemic hemodynamics and cardiac performance without adversely affecting myocardial energetics or norepinephrine balance. Thus, dopexamine hydrochloride may be a useful agent for the short-term treatment of congestive heart failure.

Adult↗

PubMed1988

Vasodilator therapy in chronic congestive heart failure.

Benefits from vasodilator therapy in patients with chronic heart failure are partly related to the severity of functional derangements. Agents with an arteriolar-dilating effect are more likely to be effective in patients with higher left ventricular outflow resistance. Vasodilators with primary venodilating properties are more likely to be effective in the presence of an increased ventricular preload. The mechanisms by which preload and left ventricular outflow resistance increase in patients with cardiac insufficiency are not well understood and may not be similar in all patients. Vasodilators also have the capacity to ameliorate myocardial metabolic functional abnormalities by influencing myocardial energetics, but the effects of different agents on coronary hemodynamics may not be uniform. Effects on renal hemodynamics may also vary, as may neurohumoral changes after therapy. Angiotensin-converting enzyme inhibitors have been shown to exert beneficial effects on both coronary and renal hemodynamics in patients with chronic heart failure, while producing favorable neurohumoral changes. These agents provide some advantages over direct-acting vasodilators in that myocardial oxygen consumption is decreased, myocardial metabolic function is improved, and norepinephrine and aldosterone levels are reduced. Further controlled studies are needed to assess the efficacy of angiotensin-converting enzyme inhibitors in relation to other vasodilators for the long-term management of these patients.

Cardiomyopathy, Dilated↗

PubMed1988

Abnormal coronary hemodynamics and myocardial energetics in patients with chronic heart failure caused by ischemic heart disease and dilated cardiomyopathy.

Coronary sinus blood flow, transmyocardial oxygen extraction, myocardial oxygen consumption, and transmyocardial lactate extraction were determined, along with systemic hemodynamics, in 34 patients with chronic stable angina without heart failure (group 1), in 66 patients with heart failure associated with coronary artery disease (group 2), and in 28 patients with heart failure caused by dilated cardiomyopathy without coronary artery disease (group 3). Compared with group 1 patients, in patients with heart failure in groups 2 and 3, resting coronary sinus blood flow was 30% and 24% higher, respectively (p less than 0.05), myocardial oxygen consumption was 25% higher (p less than 0.01), and coronary sinus oxygen content was 33% lower (p less than 0.01). The rate-pressure product was not different between the three groups. In eight patients with heart failure (five in group 2 and three in group 3), myocardial lactate production was observed without angina. Thus in patients with chronic heart failure resulting from either chronic coronary artery disease or dilated cardiomyopathy, resting coronary blood flow and myocardial oxygen consumption tend to increase probably because of an increase in myocardial oxygen requirements. Silent myocardial ischemia may also occur in both the presence and absence of coronary artery disease in patients with chronic heart failure. The abnormal coronary hemodynamics and myocardial metabolic function may play a role in causing progressive deterioration in cardiac function in dilated cardiomyopathy.

Adult↗

PubMed1987

Hemodynamic and clinical evaluation of piroximone, a new inotrope-vasodilator agent, in severe congestive heart failure.

To assess the potential utility of piroximone (MDL-19,205), an investigational inotrope-vasodilator agent, in severe heart failure, 15 patients with severe left ventricular failure refractory to conventional agents were enrolled in an acute hemodynamic study. After incremental intravenous dosing (mean total dose 1.8 +/- 0.4 mg/kg body weight), cardiac index increased (1.7 +/- 0.3 to 2.6 +/- 0.6 liters/min per m2; p less than 0.001) and left ventricular filling pressure decreased (25 +/- 7 to 19 +/- 7 mm Hg; p less than 0.001). Also decreasing significantly were right atrial pressure (13 +/- 6 to 7 +/- 5 mm Hg; p less than 0.005) and systemic vascular resistance (1,633 +/- 394 to 1,183 +/- 278 dynes.s.cm-5; p less than 0.001). Heart rate and mean arterial pressure did not change, whereas stroke work index increased significantly (13.3 +/- 4.3 to 21.6 +/- 7.3 g.m/m2; p less than 0.005). The increase in stroke work index with a concomitant decrease in left ventricular filling pressure indicates an improvement in systolic performance after treatment with piroximone. Similar responses were obtained after incremental doses of piroximone in oral solution. After oral doses of piroximone tablets, cardiac index also increased significantly (2.1 +/- 0.6 to 2.4 +/- 0.5 liters/min per m2; p less than 0.05), although this magnitude of increase was comparatively low. In a subgroup of 10 patients who underwent equilibrium gated radionuclide blood pool scintigraphy before and after intravenous piroximone, end-diastolic volume index tended to increase (106 +/- 42 to 132 +/- 60 ml/m2; p = 0.07), whereas left ventricular filling pressure decreased significantly (26 +/- 8 to 19 +/- 9 mm Hg; p less than 0.01).

Aged↗

PubMed1987

Enalaprilat, a new parenteral angiotensin-converting enzyme inhibitor: rapid changes in systemic and coronary hemodynamics and humoral profile in chronic heart failure.

Systemic and coronary hemodynamic, metabolic and humoral effects of a new intravenous angiotensin-converting enzyme inhibitor, enalaprilat, were evaluated in 14 patients with chronic heart failure. Onset of hemodynamic action occurred within 15 minutes and persisted for 6 hours. At the time of peak effect, there was a significant reduction in mean arterial pressure (-21%) and pulmonary capillary wedge pressure (-33%). Systemic vascular resistance decreased by 32% and stroke volume index increased by 20%. These systemic hemodynamic changes indicate improved left ventricular function. There was a substantial sustained reduction in rate-pressure product initially without a change in coronary sinus blood flow or myocardial oxygen consumption. There was also reduced myocardial oxygen extraction and augmented coronary sinus oxygen saturation at 30 minutes and 1 hour. In three patients, abnormal myocardial lactate extraction, present before enalaprilat, changed to uptake after enalaprilat, indicating amelioration of myocardial ischemia that was not clinically manifest. Systemic catecholamine levels and myocardial catecholamine balance did not change. Plasma renin activity increased and plasma aldosterone decreased. These findings suggest that enalaprilat produces inhibition of the angiotensin-converting enzyme and consequent beneficial systemic hemodynamic changes in heart failure. In some patients with heart failure, silent myocardial ischemia at rest can occur and can be alleviated with enalaprilat. Decreased myocardial oxygen extraction, increased coronary sinus oxygen saturation and lack of expected decrease in coronary sinus blood flow despite reduced rate-pressure product suggest transient coronary vasodilation by enalaprilat.

Aged↗

PubMedDate not supplied

The feasibility of a telecommunications service in support of outpatient congestive heart failure care in a diverse patient population.

A home telemonitoring system for patients with congestive heart failure was studied for feasibility and efficacy in a diverse patient population. Fifty patients used the service, in which they weighed themselves and answered yes/no questions about symptoms. Changes in patient weights or symptoms prompted a nurse to call the patient and/or the physician. Patients were given educational and quality of life surveys at enrollment, at 30 days, and at 6 months. The average daily usage rate was 94%. Patients were contacted 57 times--prompting 57 physician notifications, eight medication changes, and 11 nonroutine clinic visits. Patient response to lifestyle surveys showed an improvement in quality of life and improved understanding of prevention measures. Eighty-four percent of patients and 65% of physicians reported satisfaction with the system. This pilot study suggests that home telemonitoring is feasible and has clinical utility in diverse patient groups, and may improve patients' satisfaction and knowledge of self-care. (c)2000 by CHF, Inc.

Journal Article↗