A comparison of the chronotropic and dromotropic actions between adenosine triphosphate and edrophonium in patients undergoing coronary artery bypass graft surgery.
OBJECTIVE
To compare the effects of the stimulation of adenosine receptors and acetylcholine receptors in the cardiac conduction system in patients with ischemic heart disease.


METHODS
Prospective.


METHODS
University hospital.


METHODS
Patients scheduled for coronary artery bypass graft surgery (n = 37).


METHODS
The patients were divided into 3 groups: control group (n = 9), adenosine triphosphate (ATP) group (n = 12), and edrophonium group (n = 16). ATP (10 mg) or edrophonium (0.25 mg/kg) followed by saline or the same amount of saline was injected through a central venous catheter.


RESULTS
ATP induced atrioventricular block in 10 of 12 patients (83%). The ATP injection produced a more prominent prolongation in the PQ duration (P-R interval) (139%) than in the P-P interval (105%) at the last beat before the development of atrioventricular block. The prolongation in the P-P interval (11%, average 85 msec) and PQ duration during atrioventricular block disappeared immediately after the restoration of atrioventricular conduction. After edrophonium, the maximal prolongation in P-P (118%, p < 0.01) and PQ (120%, p < 0.01) intervals was the same. P-P interval remained prolonged (p < 0.01) after PQ interval returned to baseline. Neither ATP nor edrophonium affected the QRS duration.


CONCLUSIONS
These findings suggest that ATP predominantly inhibited atrioventricular conduction rather than the firing rate of sinoatrial nodes, and edrophonium inhibited both proportionally even with prolonged inhibitory action on the sinoatrial nodes. An injection of ATP is needed only when a transient cardiac standstill is requested, such as in endovascular grafting surgery. Edrophonium may be used to slow heart rate during coronary artery bypass graft surgery.
Watanabe
Seiji
S
Department of Anesthesiology, Kurume University School of Medicine, Kurume, Fukuoka, Japan. watanabe@med.kurume-u.ac.jp
Kono
Yasuo
Y
Oishi-Tobinaga
Yoko
Y
Yamada
Shin-ichi
S
Hara
Masato
M
Kano
Tatsuhiko
T
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000328:Adult; D000368:Aged; D001283:Atrioventricular Node / Q000187:drug effects* / Q000502:physiology; D001026:Coronary Artery Bypass; D004491:Edrophonium / Q000494:pharmacology*; D004562:Electrocardiography / Q000187:drug effects; D006327:Heart Block / Q000139:chemically induced; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D008875:Middle Aged; D011446:Prospective Studies
D004491:Edrophonium; D000255:Adenosine Triphosphate