Learn More
Twenty-nine dogs having undergone aseptic excision of the sinoatrial node were kept under observation, in most cases, for more than a year. Observation confirmed the instability of the new rhythm or rhythms taking over the automaticity after excision of the physiological pacemaker. This instability was particularly marked during the first ten days following(More)
We studied the effects of intravenous injections of three beta-adrenoceptor antagonists on cardiac automaticity in conscious dogs after sinoatrial node (SAN) excision. Injections were repeated for 60 days postoperatively. In controls, mean corrected sinoatrial node recovery time (CSNRT) was 535 +/- 24 ms. One milligram per kilogram of dl-propranolol did not(More)
1 Atrial pacing at progressively increasing frequencies was performed on unanaesthetized dogs through electrodes placed aseptically in the wall of the right atrium and exteriorized in the neck region. 2 Heart rate and two atrioventricular conduction (AVC) parameters, namely the Wenckebach Point (one or two systole block at the end of expiration)- and the(More)
  • 1