In AF, MBF at baseline, at hyperaemia, and at CPT is reduced, whereas CVR under hyperaemic conditions is increased. Following electrical cardioversion, these findings are partly reversible and therefore most likely secondary to the arrhythmia.

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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.

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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 µg/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 µg/kg/min for 4 h. The antiarrhythmic effect of tiapamil consists essentially in slowing A-V conduction and reducing chronic VPBs.

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.

1 The effects of a single oral dose of 5 mg pindolol (P) and 100mg 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 ,B-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 ,B-adrenoceptor blockade.