Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1615-2573
    Keywords: Congestive heart failure ; enoximone ; Peripheral circulation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of intravenous enoximone on forearm venous circulation was studied in ten healthy volunteers (group A) and in ten patients with NYHA class III–IV congestive heart failure (group B). Distensibility of the forearm capacitance vessels was assessed from pressure-volume curves by venous occlusion plethysmography using a mercury-in-rubber strain gauge. Three recordings each at 3-min intervals were obtained before the infusion and again 20 min after completion of the infusion. Venous volume changes (VV) at congesting pressures of 10, 20, and 30 mmHg before and after enoximone were compared. Forearm muscle blood flow was also measured by venous occlusion plethysmography; electrocardiogram, heart rate, and cuff blood pressure were recorded throughout. Enoximone at a dose of 1 mg/kg body weight was infused over 10 min through a peripheral vein in group A and via a central line in group B. In group A, the effect of the injection vehicle was also assessed. VV10, VV20, and VV30 did not differ from baseline values after enoximone in both groups A and B. The vehicle caused a small but significant degree of venoconstriction in group A (VV20, 2.64±0.9 to 2.48±0.83 ml/100 ml,P〈0.05; VV30, 3.47±1.27 to 3.33±1.20 ml/100 ml,P〈0.05), which could be explained by an acute response to local pain from the infusion. This effect was not evident following enoximone, perhaps as a result of its counterbalancing vasodilating action to venoconstriction induced by acute pain. Muscle blood flow increased in both groups (group A, 3.05±0.33 to 4.62±1.32 ml/100 ml/min,P〈0.01; group B, 2.33±0.93 to 3.13±0.95 ml/100 ml/min,P〈0.02) after enoximone and did not change in group A after vehicle (3.08±1.50 to 2.73±0.87,P—not significant). It is concluded that enoximone at the dose studied does not exert appreciable effects on the forearm venous system in normal subjects or in patients with heart failure.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1573-7241
    Keywords: felodipine ; congestive heart failure ; vasodilators
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The hemodynamic effects of increasing dosages of felodipine, a new calcium antagonist with selective vasodilator properties, were studied in 13 patients with chronic cardiac failure. A Swan-Ganz thermodilution catheter was positioned in the pulmonary artery and hemodynamic parameters were monitored from 9 am to 6 pm for five days. On the first and the fifth day patients received placebo (P) and on the second, third, and fourth day patients received felodipine 5, 10, and 20 mg, respectively. Symptom-limited exercise tests with a bicycle ergometer were performed on both days of P and on the fourth day. A marked reduction of systemic vascular resistance (SVR) and a significant increase of cardiac index without increments of heart rate (HR) were observed after felodipine at rest. A dose response effect could be demonstrated. During exercise a significant increment of cardiac index and decrease of pulmonary wedge pressure was observed after felodipine. Felodipine showed a potent vasodilator action on systemic circulation with significant changes on both stroke volume and filling pressures at rest and during exercise without side effects.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1573-7241
    Keywords: felodipine ; congestive heart failure ; regional blood flow
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to assess the effect of felodipine, a new calcium antagonist with vascular selectivity, on regional blood flow distribution at rest in chronic congestive heart failure, ten patients were studied during an acute test. Right heart catheterization allowed the evaluation of hemodynamic parameters; renal blood flow was calculated using paraamino-hippuric acid clearance; hepatic blood flow measurement was based on indocyanine green clearance; and limb blood flow was assessed with venous occlusion plethysmography. Blood samples were collected for the analysis of plasma catecholamines, renin, and aldosterone. All parameters were recorded in duplicate under basal conditions and after felodipine infusion. The infusion of felodipine induced a significant increase in cardiac index, stroke work index, and limb blood flow. Systemic and pulmonary arterial blood pressure, pulmonary wedge pressure, and systemic resistance underwent a significant decrease. The heart rate, pulmonary resistance, renal blood flow, and hepatic blood flow were not changed. In conclusion, felodipine was of benefit in congestive heart failure at rest in an acute test, acting through a marked decrease in vascular resistance and a consequent improvement in cardiac output and limb blood flow. No changes in renal and hepatic blood flow were observed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1573-7241
    Keywords: myocardial energetics ; congestive heart failure ; enoximone ; beta-adrenergic blockade ; metoprolol
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The hemodynamic and myocardial metabolic effects of enoximone (phosphodiesterase III inhibitor), alone or in combination with metoprolol (beta-adrenergic blocker), were studied in patients with congestive heart failure. Ten patients (New York Heart Association Class III–IV) underwent right heart and coronary sinus catheterization, and parameters were assessed at basal condition, at peak enoximone response (mean intravenous loading dose=2.2 mg/kg), and after the combination with metoprolol (mean intravenous dose=8.5 mg). Heart rate tended to increase during enoximone administration (from 102±16 to 107±16 min−1, ns) and was reduced during enoximone plus metoprolol (to 88±15 min−1, p〈0.05 vs. basal). Cardiac index was increased during enoximone (from 2.2±0.2 to 3.8±0.5 1/min/m2, p〈0.05) and decreased during enoximone plus metoprolol (to 2.8±0.5 1/min/m2, p〈0.05 vs. enoximone). Mean pulmonary wedge pressure fell during enoximone and remained reduced during enoximone plus metoprolol (from 27±9 to 9±3 and to 13±4 mmHg, respectively, both p〈0.05). Myocardial oxygen consumption did not change during enoximone (from 27±8 to 25±13 ml/min, ns) and was reduced during enoximone plus metoprolol (to 19±8 ml/min, p〈0.05 vs. basal). Myocardial lactate extraction tended to be lower during enoximone and during enoximone plus metoprolol conditions (from 38±17% to 26±20% and to 29±24%, respectively), but no statistical significance was found. Myocardial efficiency was increased during enoximone and during enoximone plus metoprolol (from 9±3% to 15±6% and to 14±6%, respectively, both p〈0.05). Thus in patients with congestive heart failure enoximone improves hemodynamics and, in most cases, it does not influence energetics. The addition of metoprolol to enoximone reduces heart rate, cardiac index, and myocardial oxygen consumption without any other major changes, producing a more physiologic hemodynamic and metabolic profile.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1573-7241
    Keywords: antiarrhythmic agents ; atrial fibrillation ; cardioversion ; electrophysiology ; refractoriness ; AF = atrial fibrillation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Summary. Objective: To prospectively evaluate right atrial refractoriness and sustained atrial fibrillation (AF) inducibility at programmed electrical stimulation in two groups of patient: a series of patients with chronic persistent AF, studied immediately after successful low energy internal atrial cardioversion, and a group of control patients without history of supraventricular arrhythmias. Patients: Nineteen patients with chronic persistent AF (mean AF duration 11 ± 10 months, range 2–61 months) submitted to successful internal low energy atrial cardioversion in fully conscious state and 11 control patients without history of supraventricular arrhythmias. Methods: An electrophysiological evaluation was performed to measure atrial refractoriness and AF inducibility, by delivering single atrial extrastimuli in high right atrium, at decremental coupling, during spontaneous sinus rhythm and after 8 beats at 600, 500, 400 and 330 ms cycle length. If sustained AF was induced the protocol was terminated. Results: During programmed atrial stimulation sustained AF was induced in 8 out 19 (42%) of the AF patients but in none of the control group. Atrial effective refractory period was significantly shorter in AF patients compared to controls both at basic cycle length, at 600 ms, 500 ms and 400 ms cycle length, meanwhile no statistically significant differences were found at 330 ms cycle length. An altered relationship between atrial effective refractory period and cycle length was found in AF patients compared to controls: the slope of linear correlation slope was significantly lower in AF group than in controls (0.04 ± 0.07 vs 0.17 ± 0.10, p 〈 0.002). Conclusions: Marked abnormalities of atrial refractoriness and of its heart rate relationship are observed after internal cardioversion of chronic persistent AF in humans and these abnormalities are associated with an high vulnerability to AF. These observations may explain the high risk of AF recurrences in the early phases following successful cardioversion. In this scenario antiarrhythmic drug therapy seems to be mandatory for reducing arrhythmia relapses.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...