Extrasystoles and Allied Arrhythmias

Extrasystoles and Allied Arralythmias

EFFECTS OF HYPERVENTILATION ON VARIOUS ARRHYTHMIAS Auricular Extrasystoles

ALTERATIONS of RS-T segment and of the T waves of the electrocardiogram have been described as a consequence of hyperventilation.5' 13 This, however, is controversial, since such changes were not seen by other investigators,' provided hyperventilation was performed in such a manner that a marked increase of the sinus rate was avoided and the respiration was not so shallow and rapid as to cause ...

Cardiac arrhythmias simulated by concealed bundle of His extrasystoles in the dog.

In 10 open-chest intact dog hearts, multiple close bipolar electrograms were obtained from various regions of both atria and the bundle of His. The bundle of His was also prematurely stimulated at varying coupling intervals following a sinus beat. At short coupling intervals, the bundle of His stimulus failed to propagate antegradely (no ventricular response) but did propagate retrogradely. Cou...

Mainstem extrasystoles.

Extrasystoles arising in the main stem of the bundle of His are generally regarded as very rare; only 7 examples have been published since their original description by Lewis in 1911 and 2 of these fail to satisfy rigid criteria for diagnosis. Four further examples, encountered in a relatively small series of tracings, are here presented and it is concluded that such extrasystoles are not so mu...

Retrograde conduction of ventricular extrasystoles with consideration of return extrasystoles.