Electrical therapeutic procedures in recurrent, drug refractory tachycardias. II. Electrical transvenous catheter ablation

In 6 patients with medicamentously therapy-refractory tachycardias (3 times auricular flutter/auricular fibrillation with very rapid atrioventricular conduction, once focal atrial tachycardia, once paroxysmal atrioventricular reentry tachycardia, once recurrent ventricular tachycardia on the basis of an interventricular reentry) percutaneous transvenous catheter ablations of the atrioventricular conduction region (bundle of His ablation, 5 cases) and the right Tawara branch (1 case), respectively, were performed. During a follow-up period of 2-26 months (on an average 10.5 +/- 8.0 months) a permanent total block in 4 cases could be obtained (3 times AV-block III. once complete right bundle branch block). In two other patients the total AV block receded to the AV block I. and II. respectively, within 2 and 8 days, respectively; in the first case the AV node reentry tachycardias were no more to be evoked, in the second case a tolerable ventricular frequency was the result during the auricular flutter recidivations. In all patients treated by means of catheter ablation after the intervention an impressive improvement of the clinical symptomatology developed. Due to possible complication and the dependence upon the pacemaker of the patients concerned which is to be expected the indication to the ablation should be made only after the exhaustion of all medicamentous possibilities and taking into consideration other electric therapy methods.     

Kinetics of histamine released from rectal mucosa

This kinetic study was performed to investigate the different tissue-influencing histamine amounts in Crohn's Disease (CD), Ulcerative Colitis (UC), patients with polyps and cancers (P.a.C.Gr) and in a Control Group (CG). For this purpose the endoscopically obtained specimens from rectal mucosa were immediately placed into 1000 microliters of Hank's incubation medium in order to determine the spontaneously released histamine amounts at the time points of 5, 10, 15, 20 and 30 minutes. Each time a volume of 100 microliters was removed from the incubation medium and the kinetic value (KV) was detected by using the single isotope radioenzymatic method. Influencing of natural histamine catabolism and the comparison of the tissue histamine release with or without air oxygen in the incubation medium using four kinetic programmes (KP1-4) provides clearly different KVs, not only between the KPs but also within the same KP. The P.a.C.Gr. shows higher kinetic values (KVs) compared with the CG. In KP1-3 the kinetic courses (KCs) of the Inflammatory Bowel Diseases (IBDs), CD and UC-both not yet divided in active (a.) or not active (n.a.) disease stages-cross the KCs of the CG several times. Only the differentiation of the IBDs in active and not active disease stages in KP4 reveals that CDa. and UCa. stand out from the CG by higher KVs, and in contrast, CDn.a. and UCn.a. have lower KVs than the CG. The released amounts of histamine in CDa. and UCa. are significantly higher than in CDn.a. and UCn.a.     

Prejunctional alpha-adrenoceptor-mediated inhibition of norepinephrine release in blood-perfused skeletal muscle in situ

The influence of alpha-adrenoceptor antagonists on the overflow of endogenous norepinephrine (NE) and vasoconstrictor responses elicited by sympathetic nerve stimulation (1-4 Hz, 2 min) was investigated in desipramine-pretreated canine blood-perfused skeletal muscle in situ. The nonselective alpha-adrenoceptor antagonist phentolamine enhanced stimulation-evoked NE overflow and reduced vasoconstrictor responses concentration-dependently. Similar effects were obtained with phenoxybenzamine (irreversible alpha-adrenoceptor antagonist). Desipramine pretreatment attenuated the enhancement of stimulation-evoked NE overflow produced by phenoxybenzamine, indicating that phenoxybenzamine also inhibits neuronal uptake. The enhancement by phenoxybenzamine was independent of the stimulation frequency, suggesting a similar engagement of prejunctional alpha-adrenoceptor-mediated inhibition of transmitter release over the frequency range studied here. The alpha 2-selective adrenoceptor antagonist yohimbine enhanced nerve stimulation-evoked NE overflow at concentrations similar to those required to antagonize vasoconstrictor responses to exogenous NE; 10-fold higher concentrations were required, however, to antagonize nerve stimulation-induced vasoconstriction. The concept of a quantitatively important prejunctional alpha 2-adrenoceptor-mediated feedback inhibition of NE release in vivo is supported by our findings in the skeletal muscle vasculature. Postjunctional alpha 2-adrenoceptors appear to be preferentially activated by circulating catecholamines but also seem to be involved in the nervous control of vascular tone.     

Impaired vagal heart rate control in coronary artery disease.

Heart rate variation in deep breathing, a sensitive non-invasive measure of cardiac parasympathetic activity, was measured in 63 patients with coronary artery disease, in 22 patients with atypical chest pain, and in 20 healthy symptom free volunteers. There was significantly less heart rate variation in deep breathing in the patients with coronary artery disease than in the healthy subjects. Twenty patients (32%) with coronary artery disease had lower than normal variation in heart rate. The patients with chest pain showed an intermediate heart rate response to deep breathing. Sinus arrhythmia in the patients with coronary artery disease was not related to the functional class, medication, number or location of narrowed vessels, or to the left ventricular ejection fraction, and end diastolic pressure. These results suggest that impairment of the parasympathetic nervous function is common in coronary artery disease.     

Short term cyclosporin A treatment of Beh?et's disease.

Eleven separate three-month courses of cyclosporin A, an oral solution 10 mg/kg/day, were administered to eight patients with Behçet''s disease with sight-threatening posterior uveitis. It was found to be effective in arresting the inflammatory activity in the eye as well as the mucocutaneous lesions of Behçet''s disease. Improvement in visual acuity was observed within one week of starting therapy. Severe exacerbations in the ocular and mucocutaneous lesions occurred on withdrawal of the drug. At this dosage side effects included hirsutism in all women, and a slight rise of serum bilirubins in two patients and of blood urea in one patient. The latter two conditions responded rapidly to dose adjustment.     

Flip-flop phenomenon and dissection of extracranial carotid artery

A case of extracranial carotid artery dissection investigated both by conventional brain imaging and by arteriography is presented. The radionuclide angiogram showed a flip-flop phenomenon on the left hemisphere. The implications, including clinical features, pathogenesis, diagnosis, and treatment are discussed. Dissection of extracranial carotid artery is a cause of carotid hypoactivity, and this phenomenon is associated directly with a flip-flop phenomenon on brain imaging.     

Changes in biochemical parameters during complete thyroid hormone deficiency of short duration in athyreotic patients

The effect of withdrawal of suppressive therapy with thyroid hormones (200 micrograms L-thyroxine/day) on serum biochemical profiles and blood cell counts were studied in ten athyreotic thyroid carcinoma patients. After 14 days off therapy, all patients but one were still clinically and biochemically euthyroid. Twenty-eight days without thyroid hormones resulted in severe clinical and biochemical (TT4, TSH) hypothyroidism. At that time, the following parameters changed significantly: CPK activities increased (in five of ten patients above normal) as well as activities of SGOT, SGPT, and LDH (means and s.d.s within the respective normal ranges). Total cholesterol and triglycerides increased within the normal range. There were minimal but significant increases of serum creatinine and of mean corpuscular volume of erythrocytes as well as decreases of serum sodium and calcium. Our study underlines the importance of further investigation if pathologic biochemical or hematologic parameters are obtained in athyreotic patients after 4 wk withdrawal of thyroid hormone therapy.     

Suicide among Swedish dentists. A ten-year follow-up study

In the present study, we have followed a national cohort of dentists, academics, i.e. people with three or more years of post-high school education, and the general population for a period of ten years, and identified all cases of recognized suicide during the period 1961 to 1970. The aim of the study was to assess whether suicide rates are higher among dentists even after adjustment for socioeconomic factors. Results show an elevated standardized mortality ratio (SMR) for male dentists compared to other male academics. Female dentists did not exhibit any increased risk. It is suggested that enhanced interest should be given to the possible etiologic role of not only psychosocial factors but also to psychoorganic consequences of mercury exposure among dentists.     

pH dependence of the blocking activity of carbisocaine and its derivatives

The blocking activity and pH dependence of carbanilate local anaesthetics, carbisocaine and its homologues, were tested on isolated rat sciatic nerves at pH 6.0, 7.2 and 8.4. Carbisocaine blocked the compound action potential more strongly than the derivatives with shorter alkoxysubstituents. The blocking potency of shorter derivatives increased with the rise of external medium pH, whereas the activity of carbisocaine increased with decreasing external pH. Quaternary compounds applied in the external medium were able to block the action potential, but in higher concentrations and with a longer half-time than their tertiary analogues. The blocking potency of quaternary derivatives correlated well with the length of the alkoxysubstituent and thus also with their lipophilicity. Extracellular pH did not consistently change the inhibitory effect of quaternized derivatives. These observations support the view that the lipophilicity of local anaesthetics is one of the possible factors determining their anaesthetic activity and the pH dependence of their effect.