[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.
D001285:Atropine / Q000494:pharmacology*; D002036:Bundle of His / Q000502:physiology; D006328:Cardiac Catheterization; D005117:Cardiac Complexes, Premature / Q000503:physiopathology; D004206:Disopyramide / Q000494:pharmacology*; D004558:Electric Stimulation; D004562:Electrocardiography; D006325:Heart Atria; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D011427:Propiophenones / Q000494:pharmacology*; D011725:Pyridines / Q000494:pharmacology*; D012849:Sinoatrial Node / Q000187:drug effects* / Q000502:physiology / Q000503:physiopathology; D013268:Stimulation, Chemical; D013997:Time Factors
D011427:Propiophenones; D011725:Pyridines; D001285:Atropine; D004206:Disopyramide
Pharmakologische Beeinflussung der "sinu-atrialen Leitungszeit" und der Sinusknotenautomatie beim Menschen