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Biomedical subjects

B Brisse

Publications and source records attributed to B Brisse.

At least 19 recordsLinked to original sources
PubMed1997

Ischemic versus idiopathic cardiomyopathy: differing neurohumoral profiles despite comparable peak oxygen uptake.

OBJECTIVE: We tested the hypothesis that neurohormonal and immunological activation differs in ischemic and idiopathic dilated cardiomyopathy since recent intervention trials indicate that ischemic cardiomyopathy seems to carry a worse prognosis than idiopathic cardiomyopathy of comparable clinical severity. METHODS: In ten patients with ischemic cardiomyopathy undergoing spiroergometric evaluation venous levels of norepinephrine, epinephrine, renin, angiotensin, atrial natriuretic peptide as well as soluble interleukin-2-receptor were determined before, during and 10 min after exercise. Results were compared to sixteen patients with idiopathic cardiomyopathy with similar peak oxygen uptake (13.3+/-3 vs. 13.6+/-3 ml/kg/min; P=ns). RESULTS: In ischemic patients, norepinephrine, angiotensin, and interleukin-2 receptor levels were significantly higher before, during and after exercise. Interleukin-2-receptor levels correlated with angiotensin. CONCLUSIONS: We conclude that in ischemic as compared to idiopathic cardiomyopathy, a more pronounced activation of the sympathetic, renin-angiotensin and T-cell immune system is present at rest, during and after exercise. These data may contribute to explain differences in response to intervention and in prognosis. They warrant further investigation.

Adult↗
PubMed1997

[Proinflammatory cytokines and cardiac pump function].

In situations of depressed myocardial function, the role of immunological mechanisms has been studied recently. In different pathophysiological situations, such as chronic heart failure, open heart surgery with extracorporal circulation, cardiac transplantation, myocardial infarction and angina pectoris, patterns have been described with elevation of proinflammatory cytokines, such as tumor necrosis factor-alpha, interleukin-1, interleukin-6, and reversible myocardial dysfunction, which may represent a final common pathway. The available data suggest a modulation of important determinants of pump function, i.e., contractility, preload, afterload, and heart rate, by cytokines. Potential mechanisms include the beta-adrenoceptor- and nitric oxide pathway, as well as a direct impact on intracellular calcium homeostasis. Interventional strategies based on this understanding are beginning to emerge.

Animals↗
PubMed1996

Interleukin-6 correlates with hemodynamic impairment during dobutamine administration in chronic heart failure.

Proinflammatory cytokines have been implicated in the pathophysiology of chronic heart failure. We determined mixed venous levels of interleukin-6 (IL6) in 18 heart transplant candidates before, 1, 4, and 24 h after initiation of dobutamine infusion (3 micrograms/kg/min) during hemodynamic evaluation. During the first 4 h of dobutamine, systemic vascular resistance decreased (1358 to 1024 dyn x s x cm-5, P = 0.01) while cardiac index (2.3 to 2.9 l/min/m2, P = 0.008) increased. Both returned to baseline after 24 h. IL6 was elevated at baseline compared to age-matched controls (1.5 (0/4.3) vs. 0 (0/0.5) P = 0.003). There was an increase in IL6 from 1.5 (0/4.3) to 3.6 (0.3/5.3) pg/ml after 24 h (P = 0.04). We found higher IL6 levels in the sicker half of patients as defined by pulmonary capillary wedge pressure > 24 mmHg (P = 0.005), mean pulmonary arterial pressure > or = 35 mmHg (P = 0.01), right atrial pressure > 13 mmHg (P = 0.02), and heart rate > or = 87/min (P = 0.02) as well as mean arterial pressure < 82 mmHg (P = 0.005). In conclusion, in this pilot study IL6 correlates with the severity of chronic heart failure during low dose dobutamine infusion.

Adult↗
PubMed1991

Diagnostic assessment of macrophage phenotypes in cardiac transplant biopsies.

Forty-one endomyocardial biopsies of the right interventricular septum have been investigated in 24 immunosuppressed patients after orthotopic heart transplantation. Monoclonal antibodies 27E10, 25F9, and RM3/1, which react with different macrophage phenotypes, and antisera MRP-8 and MRP-14, specific for proteins expressed on endothelial and monocyte cell surfaces in inflammation as well as markers for CD4+ and CD8+ T-lymphocytes, were employed in an indirect immunoperoxidase staining technique. This methodology permits more physiological recognition of the inflammatory process within the myocardium. It was possible to verify and to distinguish acute early, late and down-regulatory stages of inflammation in 33 biopsies (80%). No evidence of inflammation was found in seven biopsies (17%). Conventional histopathology with haematoxylin-eosin and Masson's trichrome was performed simultaneously, and demonstrated inflammation to be present in 23 of 41 biopsies (56%). An important findings is that CD4+ and CD8+ lymphocytes were absent in 15 of 41 specimens (37%) although there was inflammation proven by the presence of different macrophage phenotypes. The results indicate the necessity of long-term serial investigations of the physiological role of specific inflammatory macrophage phenotypes during the rejection process. It is concluded that the phenotyping of macrophage and endothelial cell differentiation antigens offers a sensitive approach to assess diagnosis of myocardial inflammation as a consequence of ongoing rejection in cardiac allografts.

Antibodies, Monoclonal↗
PubMed1990

Phenotyping of macrophages with monoclonal antibodies in endomyocardial biopsies as a new approach to diagnosis of myocarditis.

Cryostat sections of endomyocardial biopsies from 53 patients (mean age 41 +/- 5 years, 38 male and 15 female) clinically indicated to suffer from myocarditis were stained using monoclonal antibodies against subpopulations of T-lymphocytes and macrophages and with polyclonal rabbit-anti-human sera marking two calcium-binding proteins expressed by monocytes and macrophages appearing in inflammatory sites only. No inflammatory infiltrate cells were found in 13 cases (25%). Mononuclear cell infiltrates were present in 40 cases (75%). Ten biopsies showed a predominance of macrophages bearing the marker 27E10, characteristic for an early acute inflammation and 18 biopsies contained 25F9 positive macrophages, characteristic for a late stage of inflammation. An intermediate type of inflammation with both macrophage types present was found in 12 patients. Patients with immunohistologically confirmed myocarditis had atrial, ventricular or combined forms of arrhythmias (78%), scars in the vectorcardiogram (100%) and radiological evidence of cardiomegaly (36%). In conclusion, typing and endomyocardial biopsies for macrophage subpopulations is a sensitive new approach to assess the diagnosis of myocarditis.

Adult↗
PubMed1989

[Combination therapy with slow release isosorbide nitrate and diltiazem in silent myocardial ischemia].

In 11 patients (2 female, 9 male) suffering from angiographically proven CHD (age 45-60 years; 54.3 years on an average) the efficacy of a once-daily oral medication with 120 mg ISDN/50 mg ISMN and diltiazem (D) each in a long-acting preparation was examined in a placebo-controlled study. Each period lasted for 3 days; 2 capsules were given at 0700 a.m. one capsule at 5 p.m. Long-term ECG-recordings for 24 hrs (Tracker recorder, Pathfinder III) were performed twice under placebo and once during the third day of ISDN or ISMN, ISDN/ISMN + D in the morning and JSDN or ISMN in the morning and D in the afternoon. The rate of ischemic events declined from 10.4 to 4.7, 3.3 and 2.2; the duration of ischemia in 24 hours declined from 128 min to 43 min, 44 min and 34 min. The product of ST-depression (mV) and time of duration (min) showed an equivalent course. A more than 80% reduction of ischemia (duration and frequency) was achieved by a combination therapy in 72% of the patients. Minimal increase of heart rate at the beginning of ST-depression increased significantly during all periods of therapy, maximal increase of heart rate at that time showed a decrease only during combination therapy with D, the mean value did not change significantly. The once-daily application of ISDN/ISMN (50 mg) in a long-acting preparation (120 mg) led to a significant reduction of silent myocardial ischemia. The efficacy of ISDN/ISMN can be improved by D (120 mg, long acting preparation) up to a greater than 80% reduction in frequency and duration of ischemic events.

Adult↗
PubMed1987

[Clinical vectorcardiography: the Fritz-Schellong commemorative lecture].

The continuous and direct registration of the vectorcardiogram was realized by cathode-ray oscillographic methods by F. Schellong in 1937 and hence introduced into clinical diagnostics. The following development of different lead systems resulted in the standardization of the corrected orthogonal Frank system, which yielded almost identical information when compared to the Schellong system. The advantages of this continuous registration of the 3-dimensional course of depolarization concern the detection of atrial and ventricular hypertrophy, because the sensitivity, as well as the specificity, of the vectorcardiogram are superior to the ECG. Possibilities of diagnosing myocardial infarction are considerably improved with regard to sensitivity, especially of scars with dorsal and inferior localization, as well as multiple events and simultaneous disturbances of fascicular and ventricular conduction. In addition, even multiple and small defects e.g. in cardiomyopathy or myocarditis, can be detected.

Arrhythmias, Cardiac↗
PubMed1984

[Comparative studies on the anti-arrhythmic and anti-fibrillatory effectiveness of verapamil and nifedipine following acute coronary artery occlusion and reperfusion].

The ability of the two calcium-antagonists Verapamil and Nifedipine to reduce ventricular electrical instability following acute transient coronary artery occlusion and release and to prevent ventricular arrhythmias, particularly fibrillation, was evaluated on a total of 25 anaesthetized and artificially ventilated dogs. In all animals repeated coronary occlusions, lasting 20 min each, with a reperfusion period of 120 min between subsequent ligations, were performed. Time course and extent of ventricular ectopic activity were continuously registered, and the changes in ventricular vulnerability were assessed by measuring the ventricular fibrillation threshold at different times both after coronary artery occlusion and reperfusion. Verapamil displayed strong antiarrhythmic and antifibrillatory action on ventricular arrhythmias during occlusion. Ventricular tachycardia and fibrillation were completely prevented during phase la of arrhythmia (2nd to 10th min after coronary artery occlusion) and significantly reduced during phase lb (15th to 20th min after coronary artery occlusion). By contrast, Nifedipine failed to exert any antiarrhythmic and antifibrillatory effect, respectively. Following release of coronary artery occlusion, none of the compounds proved to reduce the frequency of ventricular fibrillation immediately after the onset of reperfusion. However, either drug was able to accelerate significantly the increase in the ventricular fibrillation threshold during the early post-reperfusion period. The different antiarrhythmic and antifibrillatory action of Verapamil and Nifedipine after coronary artery occlusion can be assumed to result from differences in the electropharmacological properties of these compounds, whereas the enhancement of the electrical stability of the myocardium after release of coronary artery occlusion may be due to "cardio-protective" effects of these drugs.

Animals↗
PubMed1983

Comparative study of stress reactions during oral surgery after pindolol and metoprolol.

The prophylactic effect of a single oral dose of 5 mg pindolol (P) or 100 mg metoprolol (M) on sympathetic and adrenergic stress reactions was investigated by a double blind study in 40 patients undergoing oral surgery. A reduction of systolic and diastolic blood pressure as well as heart rate was noted after both, P and M, as was the increase of these parameters during surgery. Adrenaline-, noradrenaline- and c-AMP-level were reduced after systematic beta-blockade by P only, not after M. The increased lipolysis and glycolysis during surgery were prevented by P only. The stimulation of the hypothalamic and adrenal stress reactions were not influenced by either P or M. The application of the systematic beta-blocker with ISA (P) only was suited to prevent the increase of catecholamine levels in plasma and peripheral receptor stimulation.

Adrenocorticotropic Hormone↗
PubMed1982

Beta-adrenoceptor blockade in stress due to oral surgery.

1 The effects of a single oral dose of 5 mg pindolol (P) and 100 mg metoprolol (M) were assessed in a double-blind study in 30 patients undergoing oral surgery. 2 Systolic and diastolic blood pressures and heart rate were reduced 90 min after oral medication and did not exceed initial values at rest during the procedure. 3 Noradrenaline, adrenaline and c-AMP concentrations did not differ at any time from the control values at rest after P, but were increased after local anaesthesia and during oral surgery after M as were the metabolic responses reflected by plasma concentrations of glucose and free-fatty acids. 4 Plasma levels of ACTH and cortisol showed the typical increase during the procedure, being independent of beta-adrenoceptor blockade. In contrast to the cardioselective antagonist M, prophylactic administration of the non-selective drug P prevented the sympathetic and metabolic responses to the stress of oral surgery. 5 Hypothalamic and adrenal stimulation were not reduced by either selective or non-selective beta-adrenoceptor blockade.

Adrenergic beta-Antagonists↗
PubMed1982

Management of cardiac arrhythmias with tiapamil.

37 patients with either chronic atrial fibrillation (AF), atrial premature beats (APBs) or ventricular premature beats (VPBs) received tiapamil as antiarrhythmic treatment. Tiapamil reduced A-V conduction by an average 20% in the group with AF (10 patients), the magnitude of response being dependent on the initial ventricular rate. In 3 of the 7 patients with APBs, the frequency of ectopic beats was reduced following a single i.v. injection of 1 mg/kg tiapamil. In patients with VPBs (n = 20), tiapamil (i.v. injection of 1 mg/kg followed by 4-hour i.v. infusion of 50 micrograms/kg/min in 10 patients) reduced ectopic beats by 30-50% in 6 cases, these all being patients who had not responded to previous antiarrhythmic therapy. The antiarrhythmic effect was maintained by i.v. infusion of 50 micrograms/kg/min for 4 h. The antiarrhythmic effect of tiapamil consists essentially in slowing A-V conduction and reducing chronic VPBs.

Adult↗
PubMed1982

[Age dependence of increase in heart rate after vagolysis (author's transl)].

Age dependent decrease of heart rate in sinus rhythm at rest was shown under clinical and experimental conditions and correlated with a decrease of sympathetic storage granula and membranes indicated by the tissue concentrations of c-AMP, which can be regarded as a messenger at the receptor sites. A slower maximal heart rate after Atropine and a reduced increase during oral medication with Ipratropium bromide can be explained by a reduced cardiac sympathetic threshold. The mentioned age dependent differences of the sympathetic stimulation can not be deduced to myocardial changes, because CPK and CK-MB activities were similar in the different age groups.

Adult↗
PubMed1981

Effects of cloxazolam and pindolol on the sympathetic and adrenal stress reaction during oral surgery in man.

In two studies including 73 patients the stress reducing effects of the tranquilizer Cloxazolam (Olcadil) and the beta-receptor-blocking drug pindolol (Visken) were investigated after the application of a single oral dose (3 mg Cloxazolam, 5 mg pindolol). The drugs were tested against placebo by the double blind method. After local anesthesia and during oral surgery an increase of dopamine-beta-hydroxylase (DBH)-activity, noradrenaline-, c-AMP-, ACTH and cortisol concentration was found in the placebo group. Cloxazolam antagonized all these effects, except the increase of the plasma levels of c-GMP under surgical stress. After pindolol noradrenaline concentration, DBH-activity, and c-AMP concentration were no longer increased during oral surgery. But the hypothalamic and adrenal stimulation were still present and resulted in an unchanged stress reaction of ACTH and cortisol concentration in plasma. In conclusion, the application of the beta-receptor-blocking drug pindolol prevents the stimulation of the sympathetic nervous system by suppressing the stress induced increase of plasma system by suppressing the stress induced increase of plasma noradrenaline and by blockade of peripheral beta-receptor sites. Cloxazolam reduces hypothalamic and adrenal reaction as well as peripheral ones due to stress.

Adrenal Glands↗
PubMed1981

[Antiarrhythmic therapy with flecainide in acute experimental myocardial infarction (author's transl)].

Clinical and experimental studies indicate that ventricular arrhythmias, especially ventricular fibrillation, are in almost all cases the mechanism for sudden death occurring during the first 24 hours after the onset of an ischaemic myocardial event. Therefore a higher survival rate seems to depend on advances in antiarrhythmic therapy. The present study investigates the efficacy of the new local anaesthetic compound Flecainide in reducing or preventing ventricular arrhythmias and primary ventricular fibrillation, using a standardized experimental canine preparation. Our findings demonstrate that ventricular arrhythmias due to severe transmural myocardial infarction are reduced by 80-90% following the application of Flecainide. In some cases a complete abolition of the arrhythmias can be observed. The striking reduction in ventricular ectopics includes decreases in ventricular salves and R-on-T phenomena, which may lead to sudden death by precipitating ventricular fibrillation. The beneficial antiarrhythmic and antifibrillatory actions of Flecainide affect only the arrhythmias resulting from transmural necrosis of the myocardium ("in-hospital arrhythmias", 2nd-phase arrhythmias"), whereas the incidence of early ventricular arrhythmias, especially ventricular fibrillation occurring in the very inception of myocardial ischaemia ("pre-hospital arrhythmias", "1st-phase arrhythmias") is not prevented. Changes in hemodynamics and contractility due to Flecainide are not severe, even in myocardial infarction. Thus, our results indicate that the application of Flecainide in acute myocardial infarction in man may be successful in reducing therapy-resistant ventricular dysrhythmias.

Animals↗
PubMed1980

[Combination treatment of atrial arrhythmias with quinidine-verapamil].

Between 1977 and 1979, a combined antiarrhythmic therapy with Quinidine and Verapamil was used to treat 66 patients (aged 16 to 69 years) with chronic atrial arrhythmias of different etiology. In 60% of the 43 cases with atrial fibrillation the combined therapy was effective in reversing atrial fibrillation to regular sinus rhythm. The frequency of successful responses to Quinidine - Verapamil amounted to more than twice compared with earlier therapeutic results with Quinidine only. In 65% of the 23 cases with atrial extrasystoles or atrial tachycardias a significant reduction of the ectopics could be achieved or a regular sinus rhythm could be established. Thus, the combined therapy with Quinidine - Verapamil is very effective in abolishing chronic atrial arrhythmias, especially atrial fibrillation.

Adolescent↗