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Biomedical subjects

A Both

Publications and source records attributed to A Both.

At least 55 records · Page 3Linked to original sources
PubMed1975

Direct stimulation of the sinus node in man. A possible explanation for an unusual finding during premature atrial stimulation.

An atypical behavior of the postextrasystolic pauses was observed in a 19-yr-old patient studied by His bundle electrography and programmed premature atrial stimulation. In the normal case there is a prolongation of the postextrasystolic pauses compared to the spontaneous cycle length allowing calculation of sinoatrial conduction time (SACT). In this case there were constant postextrasystolic pauses during the whole range of prematurity which were identical to the spontaneous cycle length. It is suggested that the catheter tip was accidentally positioned at the sinus node itself. The lengths of the spontaneous cycles, of the return cycles, and of the postreturn cycles showed no significant differences. Thus, one may assume that sinus node automaticity was not influenced in this case.

Adult↗
PubMed1975

[The effect of drugs on "sino-atrial conduction time" and on sinus-node automaticity in man].

The effect of atropine, propafenone, and disopyramide on sinus node automaticity and "sino-atrial conduction" was tested in normal patients and patients with the sick sinus-syndrome. "Sino-atrial conduction time" was estimated indirectly by the extrastimulus technique. Atropine (n = 11) caused a significant increase in heart rate in all patients. The sinus node recovery time was shortened in 10 patients. "Sino-atrial conduction time" decreased on an average 35% (P less than 0.01). Three patients with a sick sinus-syndrome demonstrated a change of the pattern of the postextrasystolic pauses indicating great improvement in sino-atrial conduction. Propafenone (n = 10) led to a significant prolongation of the sinus node recovery time by 17% and of the "sino-atrial conduction time" by 27%. Disopyramide (n = 8) had no significant influence on heart rate and "sino-atrial conduction time". Sinus node recovery time was not changed in 6 patients. However, in two patients with a sick sinus-syndrome a dangerous prolongation of the sinus node recovery time after application of disopyramide occurred. The results indicate that atropine enhances sinus node function and sino-atrial conduction. On the other hand, propafenone and disopyramide exert either a depressant influence on sinus node automaticity or on sino-atrial conduction.

Atropine↗