Effects of a bolus injection of adenosine triphosphate on atrioventricular conduction and hemodynamics in patients undergoing coronary artery bypass grafting.
OBJECTIVE
To investigate the effects of adenosine triphosphate (ATP) on atrioventricular (A-V) conduction and hemodynamics in patients undergoing coronary artery surgery.


METHODS
A prospective study.


METHODS
University teaching hospital.


METHODS
Patients scheduled for elective coronary artery bypass graft surgery.


METHODS
Anesthesia was induced with the same dose of intravenous fentanyl (300 microg) and midazolam (10 mg) for each patient. After the baseline measurement, a bolus dose of 10 mg of ATP (0.19+/-0.03 mg/kg, mean +/- SD) was rapidly injected through a central venous catheter. Right ventricular pacing was conducted at a rate of 40 beats/min during the development of complete A-V block.


RESULTS
ATP induced an A-V block in 10 of 12 patients (2:1 block in two patients and complete A-V block in eight patients). The onset of the A-V block was rapid (17.1+/-3.4 seconds) and the duration was short (12.1+/-7.0 seconds). Radial arterial pressure (AP) decreased with the appearance of the A-V block (p < 0.01). Heart rate (HR) returned to the baseline value quickly after the restoration of the A-V block, but recovery of radial AP was delayed. HR increased 1 minute after the ATP injection (p < 0.01). Both HR and radial AP returned to the baseline values 2 minutes after the ATP injection. ST segments on both leads II and V5 of electrocardiograms decreased more than 0.10 mV 1 minute after the ATP injection in one patient.


CONCLUSIONS
A bolus injection of 10 mg of ATP successfully induced a transient A-V block in 83% of the 12 patients. The countermeasures, including ventricular pacing, are indispensable to cope with the subsequent hypotension that may lead to myocardial ischemia, especially in patients with ischemic heart disease.
Watanabe
S
S
Department of Anesthesiology, Kurume University School of Medicine, Fukuoka, Japan.
Kono
Y
Y
Kaneko
S
S
Kano
T
T
D000255:Adenosine Triphosphate / Q000008:administration & dosage / Q000627:therapeutic use*; D018686:Anesthetics, Intravenous / Q000008:administration & dosage; D001283:Atrioventricular Node / Q000187:drug effects*; D001794:Blood Pressure / Q000187:drug effects; D001919:Bradycardia / Q000503:physiopathology / Q000628:therapy; D002304:Cardiac Pacing, Artificial; D002405:Catheterization, Central Venous; D001026:Coronary Artery Bypass; D017558:Elective Surgical Procedures; D004562:Electrocardiography / Q000187:drug effects; D005283:Fentanyl / Q000008:administration & dosage; D006327:Heart Block / Q000139:chemically induced / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D007022:Hypotension / Q000503:physiopathology / Q000628:therapy; D007275:Injections, Intravenous; D008874:Midazolam / Q000008:administration & dosage; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000503:physiopathology / Q000628:therapy; D018377:Neurotransmitter Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D011446:Prospective Studies; D013997:Time Factors; D016278:Ventricular Function, Right / Q000187:drug effects
D018686:Anesthetics, Intravenous; D018377:Neurotransmitter Agents; D000255:Adenosine Triphosphate; D008874:Midazolam; D005283:Fentanyl