Carbon dioxide in the aortic arch: coronary effects and implications in a swine study.
OBJECTIVE
CO2 angiography is considered dangerous in the aortic arch where bubbles may cause critical cerebral and cardiac ischemia. We investigated CO2 distribution, physiologic effects in the heart, methods of detection and treatments.


METHODS
Eight pigs had CO2 and iodinated contrast arch angiograms in supine and both lateral decubitus positions. An electrocardiogram, physiologic data and cardiac ultrasound were obtained. Therapies included precordial thumps and rolls to lateral decubitus positions.


RESULTS
Supine high descending aorta CO2 injections floated retrograde up the arch during diastole and preferentially filled the right coronary artery (RCA): mean score 3.5 (of 4), innominate artery 2.4, left coronary artery 1.2; n = 17; p = 0.0001. Aortic root injections preferentially filled the RCA when the animal was supine, left coronary in the right decubitus position, and showed a diffuse pattern in the left decubitus position. Right decubitus rolls filled both coronaries causing several lethal arrhythmias. Precordial thumps successfully cleared CO2. Ultrasound is a sensitive detector of myocardial CO2.


CONCLUSIONS
Arch distribution of CO2 primarily involves the RCA. Diagnostic ultrasound detects cardiac CO2 well. Precordial thumps are an effective treatment.
Culp
William C
WC
Department of Radiology, University of Arkansas for Medical Sciences, 4301 W. Markham Street, Slot 556, Little Rock, AR 72205-7199, USA. culpwilliamc@uams.edu
Porter
Thomas R
TR
Culp
William C
WC
Vonk
Brian N
BN
D015901:Angiography, Digital Subtraction; D000818:Animals; D001013:Aorta, Thoracic / Q000378:metabolism*; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D016122:Brachiocephalic Trunk / Q000378:metabolism; D002245:Carbon Dioxide / Q000008:administration & dosage* / Q000097:blood*; D003331:Coronary Vessels / Q000378:metabolism; D003971:Diastole / Q000187:drug effects / Q000502:physiology; D005260:Female; D006339:Heart Rate / Q000187:drug effects / Q000502:physiology; D006352:Heart Ventricles / Q000378:metabolism; D007269:Injections, Intra-Arterial; D008297:Male; D023421:Models, Animal; D008955:Models, Cardiovascular; D013348:Subclavian Artery / Q000378:metabolism; D013552:Swine; D013599:Systole / Q000187:drug effects / Q000502:physiology; D013997:Time Factors; D018084:Ultrasonography, Interventional
D002245:Carbon Dioxide