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INFLOW OCCLUSION FOR CORONARY ARTERIOGRAPHY: EXPERIMENTAL COMPARISON WITH OTHER METHODS
I N F L O W OCCLUSION FOR C O R O N A R Y
ARTERIOGRAPHY:
EXPERIMENTAL COMPARISON W I T H OTHER METHODS /. Y. Templeton,
111, M.D., R. R. Greening, M.D. (by
C. Fineberg, M.D., T. G. Peters, M.D. (by invitation), (by invitation),
C. L. Reese, M.D. (by invitation),
(by invitation),
and S. Wallace, M.D. (by invitation),
invitation), ]. R. Griffith,
D. L. Clark,
M.D.
M.D.
Philadelphia,
Pa.
T
HE considerable measure of success attained during the last decade in the surgical relief of occlusive arterial disease has intensified the interest of vas cular surgeons in direct attack upon obstruction of the coronary arteries. For such an approach to be effective, adequate and safe means of radiologic visuali zation of the coronary arteries is necessary for the selection of patients for op eration and for the guidance of the surgeon during operation. Objective determination of the results of operation is of equal importance. Simple opacification of the aorta has served nicely to demonstrate its major branches, both abdominal and thoracic, and satisfactory coronary arteriograms have been obtained by flooding the base of the aorta with opaque mate rial. 7 ' "■ 15> 61 In man, unfortunately, the coronary arteries cannot be satisfac torily visualized in this way with consistency,12 so that various modifications have been introduced to improve the quality of the studies. Sones19 has overcome the problem of dissipation of the opaque medium in the aortic stream in a large and well-conducted series of arteriograms done by selective catheterization of the coronary orifices. Thai 21 has used a short injection of opaque material trig gered by the R wave of the electrocardiogram so that the contrast fills the sinuses of Valsalva at the end of systole and the first half of diastole. Several methods of temporarily reducing aortic flow have been introduced. Dotter and Frische 8 injected opaque below a balloon inflated in the ascending aorta, restricting the dye to the occluded segment. Rather high proximal pressures were observed, averaging 78 per cent greater than control systolic levels. Increased intrathoracic pressure to reduce cardiac output has proved helpful. Freeman and his asso ciates" used the Valsalva maneuver as did Nordenstrom 13 in cooperative patients. Boerema and Blickman 5 increased endobronchial pressure under anesthesia. Nordenstrom used this method in patients who could not perform an adequate Prom the Jefferson Medical College of Philadelphia, Philadelphia, Pa. Supported by U. S. Public Health Service Grant H-7096. Read at the Forty-third Annual Meeting of The American Association for Thoracic Surgery at Houston, Texas, April 8-10, 1963. 818
Vol. 46, No. 6 December, 1963
CORONARY A R T E R I O G R A P H Y
819
Valsalva maneuver. Partial venous occlusion by the inflation of a balloon in the inferior vena cava has proved useful in the hands of Brofman and Elder 6 and Sloan.18 Abbott 1 described the use of balloons in both superior and inferior venae cavae but indicated a preference for other methods. Cardiac arrest in duced by the intraaortic injection of acetylcholine has been employed by Arnulf3 and Anlyan and colleagues.2 In addition to the improvement afforded by cessation of cardiac output, the interruption of cardiac motion simplifies the technical problems from the standpoint of the radiologist, particularly in heavy subjects. A significant improvement was made by Bilgutay and Lillehei4 who added an intracardiac pacemaker electrode, which afforded positive control of the period of arrest and avoided potentially dangerous arrhythmias during the recovery period. They followed the injection of opaque, with carbon dioxide which they believed improved the quality of the films. Haight and co-workers10 studied the effects of increased intrabronchial pressure, inferior vena caval balloon oc clusion, neostigmine-produced bradycardia, nitroglycerin and amyl nitrite vasodilatation, and Mecholyl-induced arrest in a series of animals. They were not convinced that diminution of cardiac inflow significantly improved visualization in their animals but concluded that arterial dilators consistently improved vis ualization of normal coronary arteries and of arteries distal to experimental narrowing. METHODS
Adult mongrel dogs were anesthetized with sodium pentobarbital without mechanical ventilation. An abdominal aortic catheter was connected to a strain gauge and oscillograph for aortic pressure recordings. The standard limb leads of the electrocardiogram were recorded by the same oscillograph. Periods of inflow occlusion and increased endobronchial pressure and times of injection of drugs and opaque were recorded on the oscillograph paper. The electroencephalo grams were recorded separately. An opaque catheter was placed in the base of the aorta percutaneously through a femoral artery by the method of Seldinger," 15 ml. of 70 per cent Renografin was injected by means of a pressure injector. A series of films were exposed with the use of the Elema Schonander film changer or a cine arteriogram was made using the Marconi image intensifier. Studies were made using simple flooding of the aorta, inflow occlusion, acetylcholine arrest, and increased endothoracic pressure. The sequence of the methods was varied. For inflow occlusion, a catheter bearing a latex balloon was passed into the right atrium through a cutdown over the sapheno-femoral junction. Inflow oc clusion was produced by inflating the balloon with carbon dioxide to a volume (usually 50 ml.) that filled the right atrium under the image intensifier and caused the arterial pressure to fall to the base line. Inflow occlusion was main tained for an average duration of 20 seconds; the longest period was 39 seconds. For cardiac arrest, 5 mg. of acetylcholine was injected by the pressure syringe through the aortic catheter immediately preceding the injection of the contrast medium. Atropine (gr. %oo) was injected through the aortic catheter to terminate the arrest. A pacemaker was not used.
T E M P L E T O N E T AL.
820
J. Thoracic and Cardiovas. Surg.
When increased intrathoracic pressure was employed, a cuffed endotracheal tube was passed and the endobronchial pressure was elevated by administering oxygen vented through an under water blowoff tube so that the aortic pressure fell to approximately 60 per cent of control values.
Pig. 1.—Coronary arteriograms with inflow occlusion. RESULTS
In 14 animals, coronary arteriograms were done using right atrial balloon inflow occlusion and acetylcholine-induced cardiac arrest. Increased endotracheal pressure was used on three occasions and simple flooding of the base of the aorta in three. All these animals survived without evidence of impairment of function. One additional animal died of ventricular fibrillation which developed after acetylcholine-induced cardiac arrest before an inflow occlusion study could be done. Roentgenograms.—The coronary arteriograms were evaluated and graded on a scale of 1 to 4. In all 14 dogs results were satisfactory with both inflow occlu sion and acetylcholine arrest and there was no significant difference in the qual ity of the films. With inflow occlusion there were 7 animals with a grade of 4 and 7 with a grade of 3. With acetylcholine-induced arrest there were 8 with a grade of 4, 5 with a grade of 3, and 1 with a grade of 2. Three of these animals also had increased endotracheal pressure and simple flooding of the aorta. These studies obtained in this small number of dogs were less satisfactory. Kepresentative arteriograms made by the several methods are shown in Figs. 1, 2, and 3.
Vol. 46. No. 6 December, 1963
COEONABY A E T E E I O G E A P H Y
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Fig. 2.—Coronary arteriograms with acetylcholine-induced arrest.
Fig. 3.—Left: Coronary arteriograms with endofracheal pressure. Bight: with simple flooding of the aorta.
Coronary
arteriogram
TEMPLETON ET AL.
822
J. Thoracic and Cardiovas. Surg.
Electrocardiograms.—Electrocardiograms were recorded during 25 inflow occlusions in 14 dogs. The arrhythmias noted are shown in Table I. The pre mature atrial and ventricular contractions were usually quite few in number but in 4 experiments were numerous. Atrial fibrillation persisted during occlu sion in 2 dogs. The supraventricular tachycardia and ventricular tachycardia were of short duration, usually 6 to 7 complexes. P waves became taller or widened on inflation of the balloon, and S-T depression and T-wave inversion occurred as pressure fell. All arrhythmias reverted spontaneously to regular sinus rhythm and all complexes reverted to normal configuration within a few seconds after deflation of the balloon and restoration of arterial pressure. TABLE I.
ELECTROCARDIOGRAMS INFLOW OCCLUSION ( 2 5 EXPERI MENTS)
ACETYLCHOLINE ( 1 7 EXPERI MENTS)
ENDOTRACHEAL PRESSURE (5 E X P E R I MENTS)
Arrhythmias Premature atrial contractions Premature ventricular contractions Atrial fibrillation Nodal rhythm Supraventricular tachycardia Ventricular tachycardia Ventricular fibrillation
17 21 2 1 6 7 0
1 4 14 0 0 3 1
1 0 0 0 0 0 0
Complex Changes P-wave changes ST depression and T-wave inversion ST depression alone
8 14 1
0 12 3
3 2 0
CHANGES
Cardiac arrest was induced with acetylcholine seventeen times in 15 dogs. There was no electrical activity during arrest in these dogs except in 1 who had an idioventricular rhythm after injection so that the changes in the rhythm and complexes noted in Table I occurred during recovery and not during cir culatory arrest, as in the first group. The pattern of recovery most often observed was that of beginning idioventricular contractions going on to a rapid irregular response to atrial fibrillation which reverted to regular sinus rhythm by the end of the experiment in all but 1 dog in which conversion occurred by the next day. All had atrial tachycardia following the administration of atropine. In 2 animals, ventricular tachycardia reverted within 60 seconds. In the third, intra venous administration of procaine was necessary. S-T segment depression and T-wave inversion persisted during the period of rapid ventricular response for 5 to 60 seconds and reverted to normal with return of arterial pressure. One animal died in ventricular fibrillation. I n the 5 experiments on 4 dogs with increased endotracheal pressure, no arrhythmias were noted and S-T depression and T-wave inversion occurred in only 2. In these animals, blood pressure fell to an average of 60 per cent of con trol values and the ischemic changes were noted in the 2 dogs with the greatest fall.
823
CORONARY A R T E R I O G R A P H Y
Vol. 46, No. 6
December. 1963
Electroencephalograms.—The electroencephalograms, as shown in Table II, were altered to a much greater degree in the dogs who had inflow occlusion than in those subjected to acetylcholine arrest. In 3 of 4 dogs with acctylcholineinduced arrest, there were no changes and only a fleeting abnormality in the fourth. However, inflow occlusion was accompanied by electroencephalographic slowing in 3 of 5 animals and by generalized muscle contractions in a fourth. The periods of circulatory arrest were comparable in these two groups of ani mals, and the alterations in the electroencephalogram began from 1 to 15 seconds after balloon inflation. There was no correlation with the quality of the arteriograms. TABLE I I .
DOG
CIRCULATORY ARREST SEC.)
ELECTROENCEPHALOGRAMS
T I M E AFTER ARREST CHANGES BEGAN ( S E C . )
Inflov. Occlusion 15
1
28
1
33
4
6
19
11
12
26
1
14
15
Acetylcholine
-
1 6 12
23 24 22
20
14
15
-
CHANGES I N ELECTROENCEPHALOGRAM
2'/4-3 cycles per second 50-75 microvolt waves 2 ^ - 3 cycles per second 50-75 microvolt waves EEG blocked by generalized tonic muscular contractions 4 cycles per second 75-100 microvolt waves None
Arrest None None 3Vi-4 cycles per second 50 microvolt waves None
DISCUSSION
Opacification of the coronary arteries in dogs was accomplished equally well with right atrial balloon inflow occlusion and acetylcholine cardiac arrest. Interruption of left ventricular output permitted opaque to fill the coronary arterial tree instead of being swept peripherally in the aortic blood stream. In flow occlusion Avas well tolerated by the normal dog heart. The arrhythmias, mainly occasional premature atrial and ventricular contractions, disappeared immediately upon the release of the tamponading balloon and at the same time changes in S-T segments and T waves reverted to normal. In contrast, the ar rhythmias during the period of recovery from acetylcholine arrest were more persistent and prolonged and 1 dog died of ventricular fibrillation. It should be pointed out, however, that Bilgutay and Lillehei4 have greatly reduced this problem in acetylcholine-induced arrest by controlling ventricular contractions with an internal pacemaker during resuscitation. The electroencephalographic changes with inflow occlusion are considerably greater than those encountered in acetylcholine arrest. Although the periods of circulatory arrest were somewhat longer with inflow occlusion, the changes all took place within a time period
824
TEMPLETON ET AL.
J. Thoracic and Cardiovas. Surg.
equalling or less than that of acetylcholine arrest. These changes can be attribvited to interruption of the venous inflow to the heart. The same type of electroeneephalographie change has been previously observed by Pampiglione and Watcrston" when the superior vena cava was occluded in man. Storm Van Leeuwen and co-authors20 noted that the electroencephalogram slowed more rapidly following occlusion of the venous outflow of the brain than in distur bances of the arterial supply. In none of the dogs was there any indication of neurological injury. SUMMARY
Coronary artcriograms of comparable quality were obtained in dogs with the use of inflow occlusion produced by inflation of a right atrial balloon and cardiac arrest produced by acetylcholine. Arrhythmias and ST-T segment changes disappeared immediately after deflation in the balloon scries but were much more persistent with acetylcholine. However, slowing of the electroen cephalogram was noted in three of five experiments, with inflow occlusion and generalized muscle contractions in a fourth. In acetylcholine-induced arrest the electroencephalogram was unchanged in three experiments and showed only fleeting abnormality in a fourth.
REFERENCES
1. Abbott, O.: Discussion of Anlyan, W. G., ot al. 2 2. Anlyan, W. G., Baylin, G. J., Fabrikant, J . I., and Trumbo, It. B . : Studies in Coronary Arteriography, Surgery 45: 8, 1959. 3. Arnulf, G.: De 1'arteriographic mcthodique des coronaires grace a 1'acetylcholine, Arch. mal. coeur 52: 1121, 1959. 4. Bilgutay, A. M., and Lillehei, C. W . : Single and Double Contrast Coronary Arteriography: Utilizing Acetylcholine Asystole With Controlled Return of Heart Eate Using a Cardiac Pacemaker, J . THORACIC & CARDIOVAS. SURG. 44: 617-627, 1962.
5. Boerema, T., and Bliekman, J . E . : Eeduced Intrathoracic Circulation as an Aid in Angio cardiography, J . THORACIC SURG. 30: 129-142, 1955.
6. Brofman, B . L., and Elder, J . C.: Cardioaortic Fistula: Temporary Circulatory Occlusion as an Aid in Diagnosis, Circulation 16: 77-86, 1957. 7. Di Guglielmo, L., and Guttadauro, M.: Eoentgenologic Visualization of the Coronary Ar teries in Living Subjects (413 Observations), Sc. med. ital. 3 : 446, 1955. 8. Dotter, C. T., and Frische, H . L . : Visualization of Coronary Circulation by Occlusion Aortography: A Practical Method, Eadiology 7 1 : 502, 1958. 9. Freeman, N . E., Fullenlove, T. M., Wylie, E . J., and Gilfillan, R. S.: The Valsalva Maneu ver: An Aid for the Contrast Visualization of the Aorta and Great Vessels, Ann. Surg. 130: 398, 1949. 10. Haight, C , Figley, M. M., Ellsworth, W. J., Sloan, H., Meyer, J . A., Berk, M. S., and Boblitt, D. E . : Experimental Coronary Arteriography: The Effects of Some Modifi cations of the Circulation, J . Surg. Ees. 2 : 7, 1962. 11. Hoyos, J . M., and del Campo, C. G.: Angiography of Thoracic Aorta and Coronary Ves sels, Eadiology 50: 211-213, 1948. 12. Lehman, J . S.: Coronary Arteriography: Practical Considerations, Progr. Cardiovas. Dis. 2: 36, 1959. 13. Nordenstrom B., Ovenfors, C. O., and Tbrnell, G.: Coronary Angiography in 100 Cases of Ischemic H e a r t Disease, Eadiology 78: 714-724, 1962. 14. Pampiglione, G., and Waterston, D. J . : EEG Observations During Changes in Venous and Arterial Pressure Cerebral Anoxia and the Electroencephalogram, edited by IT. Gastant, and J . S. Meyer, Springfield, 111., 1961, Charles C Thomas, Publisher, p. 250. 15. Perl, F . , Grey, N . N., and Friedman, B . : Retrograde Aortography With Special Catheter, Including Demonstration of Coronary Arteries, Ann. Surg. 132: 959-964, 1950.
Vol. 46, No. 6
December, 1965
CORONARY A R T E R I O G R A P H Y
825
16. Radner, S.: An A t t e m p t a t the Roentgenologie Visualization of Coronary Blood Vessels in Man, Acta radiol. 26: 497, 1945. 17. Seldinger, S.: Catheter Replacement of the Needle in Percutaneous Arteriography, Acta radiol. 39: 368-376, 1963. 18. Sloan, H. E.: Discussion of Anlyan, W. G., et al.2 19. Sones, F. M., Jr., Shirky, E. K., Proudfit, W. L., and Westcoat, R. N . : Cine-Coronary Arteriography, Proceedings of the 32nd Annual Scientific Sessions, American Heart Association, p. 773, 1959. 20. Storm Van Leeuwen, W., and others: EEG During Heart Operations With Artificial Cir culation Cerebral Anoxia and the Electroencephalogram, edited by H. Gastaut, and J . S. Meyer, Springfield, 111., 1961, Charles C Thomas, Publisher, p. 268. 21. Thai, A. P . : The Clinical Usage of Coronary Arteriography, Angiology 12: 238, 1960. DISCUSSION DR. TIMOTHY TAKARO, Oteen, N. C—We have also been interested in visualizing the coronary tree. I n dogs, we have used a technique known to radiologists for several years but not yet applied to angiography; that is, the technique of direct roentgenographic mag nification, using the diverging rays from an ultra-fine focal spot tube, much in the manner of a magnifying glass. [Slide] The usual target-object-film relationships are altered so that the object (the heart in this instance) is placed halfway between the tube and the film. I n this angiogram of an animal one can see fine branches of the coronary arteries on the order of 100 micra in diameter, judging from the diameter of these wire vascular staples of 300 micra diameter here in the superior vena cava, at the same level as the coronary arteries. For clinical work we are going to need a much more powerful ultra-fine focal spot xray tube in order to apply this technique to patients. This is being built at present and we hope it will be powerful enough to magnify the coronary arteries of patients.
ARTERIOGRAPHY:
EXPERIMENTAL COMPARISON W I T H OTHER METHODS /. Y. Templeton,
111, M.D., R. R. Greening, M.D. (by
C. Fineberg, M.D., T. G. Peters, M.D. (by invitation), (by invitation),
C. L. Reese, M.D. (by invitation),
(by invitation),
and S. Wallace, M.D. (by invitation),
invitation), ]. R. Griffith,
D. L. Clark,
M.D.
M.D.
Philadelphia,
Pa.
T
HE considerable measure of success attained during the last decade in the surgical relief of occlusive arterial disease has intensified the interest of vas cular surgeons in direct attack upon obstruction of the coronary arteries. For such an approach to be effective, adequate and safe means of radiologic visuali zation of the coronary arteries is necessary for the selection of patients for op eration and for the guidance of the surgeon during operation. Objective determination of the results of operation is of equal importance. Simple opacification of the aorta has served nicely to demonstrate its major branches, both abdominal and thoracic, and satisfactory coronary arteriograms have been obtained by flooding the base of the aorta with opaque mate rial. 7 ' "■ 15> 61 In man, unfortunately, the coronary arteries cannot be satisfac torily visualized in this way with consistency,12 so that various modifications have been introduced to improve the quality of the studies. Sones19 has overcome the problem of dissipation of the opaque medium in the aortic stream in a large and well-conducted series of arteriograms done by selective catheterization of the coronary orifices. Thai 21 has used a short injection of opaque material trig gered by the R wave of the electrocardiogram so that the contrast fills the sinuses of Valsalva at the end of systole and the first half of diastole. Several methods of temporarily reducing aortic flow have been introduced. Dotter and Frische 8 injected opaque below a balloon inflated in the ascending aorta, restricting the dye to the occluded segment. Rather high proximal pressures were observed, averaging 78 per cent greater than control systolic levels. Increased intrathoracic pressure to reduce cardiac output has proved helpful. Freeman and his asso ciates" used the Valsalva maneuver as did Nordenstrom 13 in cooperative patients. Boerema and Blickman 5 increased endobronchial pressure under anesthesia. Nordenstrom used this method in patients who could not perform an adequate Prom the Jefferson Medical College of Philadelphia, Philadelphia, Pa. Supported by U. S. Public Health Service Grant H-7096. Read at the Forty-third Annual Meeting of The American Association for Thoracic Surgery at Houston, Texas, April 8-10, 1963. 818
Vol. 46, No. 6 December, 1963
CORONARY A R T E R I O G R A P H Y
819
Valsalva maneuver. Partial venous occlusion by the inflation of a balloon in the inferior vena cava has proved useful in the hands of Brofman and Elder 6 and Sloan.18 Abbott 1 described the use of balloons in both superior and inferior venae cavae but indicated a preference for other methods. Cardiac arrest in duced by the intraaortic injection of acetylcholine has been employed by Arnulf3 and Anlyan and colleagues.2 In addition to the improvement afforded by cessation of cardiac output, the interruption of cardiac motion simplifies the technical problems from the standpoint of the radiologist, particularly in heavy subjects. A significant improvement was made by Bilgutay and Lillehei4 who added an intracardiac pacemaker electrode, which afforded positive control of the period of arrest and avoided potentially dangerous arrhythmias during the recovery period. They followed the injection of opaque, with carbon dioxide which they believed improved the quality of the films. Haight and co-workers10 studied the effects of increased intrabronchial pressure, inferior vena caval balloon oc clusion, neostigmine-produced bradycardia, nitroglycerin and amyl nitrite vasodilatation, and Mecholyl-induced arrest in a series of animals. They were not convinced that diminution of cardiac inflow significantly improved visualization in their animals but concluded that arterial dilators consistently improved vis ualization of normal coronary arteries and of arteries distal to experimental narrowing. METHODS
Adult mongrel dogs were anesthetized with sodium pentobarbital without mechanical ventilation. An abdominal aortic catheter was connected to a strain gauge and oscillograph for aortic pressure recordings. The standard limb leads of the electrocardiogram were recorded by the same oscillograph. Periods of inflow occlusion and increased endobronchial pressure and times of injection of drugs and opaque were recorded on the oscillograph paper. The electroencephalo grams were recorded separately. An opaque catheter was placed in the base of the aorta percutaneously through a femoral artery by the method of Seldinger," 15 ml. of 70 per cent Renografin was injected by means of a pressure injector. A series of films were exposed with the use of the Elema Schonander film changer or a cine arteriogram was made using the Marconi image intensifier. Studies were made using simple flooding of the aorta, inflow occlusion, acetylcholine arrest, and increased endothoracic pressure. The sequence of the methods was varied. For inflow occlusion, a catheter bearing a latex balloon was passed into the right atrium through a cutdown over the sapheno-femoral junction. Inflow oc clusion was produced by inflating the balloon with carbon dioxide to a volume (usually 50 ml.) that filled the right atrium under the image intensifier and caused the arterial pressure to fall to the base line. Inflow occlusion was main tained for an average duration of 20 seconds; the longest period was 39 seconds. For cardiac arrest, 5 mg. of acetylcholine was injected by the pressure syringe through the aortic catheter immediately preceding the injection of the contrast medium. Atropine (gr. %oo) was injected through the aortic catheter to terminate the arrest. A pacemaker was not used.
T E M P L E T O N E T AL.
820
J. Thoracic and Cardiovas. Surg.
When increased intrathoracic pressure was employed, a cuffed endotracheal tube was passed and the endobronchial pressure was elevated by administering oxygen vented through an under water blowoff tube so that the aortic pressure fell to approximately 60 per cent of control values.
Pig. 1.—Coronary arteriograms with inflow occlusion. RESULTS
In 14 animals, coronary arteriograms were done using right atrial balloon inflow occlusion and acetylcholine-induced cardiac arrest. Increased endotracheal pressure was used on three occasions and simple flooding of the base of the aorta in three. All these animals survived without evidence of impairment of function. One additional animal died of ventricular fibrillation which developed after acetylcholine-induced cardiac arrest before an inflow occlusion study could be done. Roentgenograms.—The coronary arteriograms were evaluated and graded on a scale of 1 to 4. In all 14 dogs results were satisfactory with both inflow occlu sion and acetylcholine arrest and there was no significant difference in the qual ity of the films. With inflow occlusion there were 7 animals with a grade of 4 and 7 with a grade of 3. With acetylcholine-induced arrest there were 8 with a grade of 4, 5 with a grade of 3, and 1 with a grade of 2. Three of these animals also had increased endotracheal pressure and simple flooding of the aorta. These studies obtained in this small number of dogs were less satisfactory. Kepresentative arteriograms made by the several methods are shown in Figs. 1, 2, and 3.
Vol. 46. No. 6 December, 1963
COEONABY A E T E E I O G E A P H Y
821
Fig. 2.—Coronary arteriograms with acetylcholine-induced arrest.
Fig. 3.—Left: Coronary arteriograms with endofracheal pressure. Bight: with simple flooding of the aorta.
Coronary
arteriogram
TEMPLETON ET AL.
822
J. Thoracic and Cardiovas. Surg.
Electrocardiograms.—Electrocardiograms were recorded during 25 inflow occlusions in 14 dogs. The arrhythmias noted are shown in Table I. The pre mature atrial and ventricular contractions were usually quite few in number but in 4 experiments were numerous. Atrial fibrillation persisted during occlu sion in 2 dogs. The supraventricular tachycardia and ventricular tachycardia were of short duration, usually 6 to 7 complexes. P waves became taller or widened on inflation of the balloon, and S-T depression and T-wave inversion occurred as pressure fell. All arrhythmias reverted spontaneously to regular sinus rhythm and all complexes reverted to normal configuration within a few seconds after deflation of the balloon and restoration of arterial pressure. TABLE I.
ELECTROCARDIOGRAMS INFLOW OCCLUSION ( 2 5 EXPERI MENTS)
ACETYLCHOLINE ( 1 7 EXPERI MENTS)
ENDOTRACHEAL PRESSURE (5 E X P E R I MENTS)
Arrhythmias Premature atrial contractions Premature ventricular contractions Atrial fibrillation Nodal rhythm Supraventricular tachycardia Ventricular tachycardia Ventricular fibrillation
17 21 2 1 6 7 0
1 4 14 0 0 3 1
1 0 0 0 0 0 0
Complex Changes P-wave changes ST depression and T-wave inversion ST depression alone
8 14 1
0 12 3
3 2 0
CHANGES
Cardiac arrest was induced with acetylcholine seventeen times in 15 dogs. There was no electrical activity during arrest in these dogs except in 1 who had an idioventricular rhythm after injection so that the changes in the rhythm and complexes noted in Table I occurred during recovery and not during cir culatory arrest, as in the first group. The pattern of recovery most often observed was that of beginning idioventricular contractions going on to a rapid irregular response to atrial fibrillation which reverted to regular sinus rhythm by the end of the experiment in all but 1 dog in which conversion occurred by the next day. All had atrial tachycardia following the administration of atropine. In 2 animals, ventricular tachycardia reverted within 60 seconds. In the third, intra venous administration of procaine was necessary. S-T segment depression and T-wave inversion persisted during the period of rapid ventricular response for 5 to 60 seconds and reverted to normal with return of arterial pressure. One animal died in ventricular fibrillation. I n the 5 experiments on 4 dogs with increased endotracheal pressure, no arrhythmias were noted and S-T depression and T-wave inversion occurred in only 2. In these animals, blood pressure fell to an average of 60 per cent of con trol values and the ischemic changes were noted in the 2 dogs with the greatest fall.
823
CORONARY A R T E R I O G R A P H Y
Vol. 46, No. 6
December. 1963
Electroencephalograms.—The electroencephalograms, as shown in Table II, were altered to a much greater degree in the dogs who had inflow occlusion than in those subjected to acetylcholine arrest. In 3 of 4 dogs with acctylcholineinduced arrest, there were no changes and only a fleeting abnormality in the fourth. However, inflow occlusion was accompanied by electroencephalographic slowing in 3 of 5 animals and by generalized muscle contractions in a fourth. The periods of circulatory arrest were comparable in these two groups of ani mals, and the alterations in the electroencephalogram began from 1 to 15 seconds after balloon inflation. There was no correlation with the quality of the arteriograms. TABLE I I .
DOG
CIRCULATORY ARREST SEC.)
ELECTROENCEPHALOGRAMS
T I M E AFTER ARREST CHANGES BEGAN ( S E C . )
Inflov. Occlusion 15
1
28
1
33
4
6
19
11
12
26
1
14
15
Acetylcholine
-
1 6 12
23 24 22
20
14
15
-
CHANGES I N ELECTROENCEPHALOGRAM
2'/4-3 cycles per second 50-75 microvolt waves 2 ^ - 3 cycles per second 50-75 microvolt waves EEG blocked by generalized tonic muscular contractions 4 cycles per second 75-100 microvolt waves None
Arrest None None 3Vi-4 cycles per second 50 microvolt waves None
DISCUSSION
Opacification of the coronary arteries in dogs was accomplished equally well with right atrial balloon inflow occlusion and acetylcholine cardiac arrest. Interruption of left ventricular output permitted opaque to fill the coronary arterial tree instead of being swept peripherally in the aortic blood stream. In flow occlusion Avas well tolerated by the normal dog heart. The arrhythmias, mainly occasional premature atrial and ventricular contractions, disappeared immediately upon the release of the tamponading balloon and at the same time changes in S-T segments and T waves reverted to normal. In contrast, the ar rhythmias during the period of recovery from acetylcholine arrest were more persistent and prolonged and 1 dog died of ventricular fibrillation. It should be pointed out, however, that Bilgutay and Lillehei4 have greatly reduced this problem in acetylcholine-induced arrest by controlling ventricular contractions with an internal pacemaker during resuscitation. The electroencephalographic changes with inflow occlusion are considerably greater than those encountered in acetylcholine arrest. Although the periods of circulatory arrest were somewhat longer with inflow occlusion, the changes all took place within a time period
824
TEMPLETON ET AL.
J. Thoracic and Cardiovas. Surg.
equalling or less than that of acetylcholine arrest. These changes can be attribvited to interruption of the venous inflow to the heart. The same type of electroeneephalographie change has been previously observed by Pampiglione and Watcrston" when the superior vena cava was occluded in man. Storm Van Leeuwen and co-authors20 noted that the electroencephalogram slowed more rapidly following occlusion of the venous outflow of the brain than in distur bances of the arterial supply. In none of the dogs was there any indication of neurological injury. SUMMARY
Coronary artcriograms of comparable quality were obtained in dogs with the use of inflow occlusion produced by inflation of a right atrial balloon and cardiac arrest produced by acetylcholine. Arrhythmias and ST-T segment changes disappeared immediately after deflation in the balloon scries but were much more persistent with acetylcholine. However, slowing of the electroen cephalogram was noted in three of five experiments, with inflow occlusion and generalized muscle contractions in a fourth. In acetylcholine-induced arrest the electroencephalogram was unchanged in three experiments and showed only fleeting abnormality in a fourth.
REFERENCES
1. Abbott, O.: Discussion of Anlyan, W. G., ot al. 2 2. Anlyan, W. G., Baylin, G. J., Fabrikant, J . I., and Trumbo, It. B . : Studies in Coronary Arteriography, Surgery 45: 8, 1959. 3. Arnulf, G.: De 1'arteriographic mcthodique des coronaires grace a 1'acetylcholine, Arch. mal. coeur 52: 1121, 1959. 4. Bilgutay, A. M., and Lillehei, C. W . : Single and Double Contrast Coronary Arteriography: Utilizing Acetylcholine Asystole With Controlled Return of Heart Eate Using a Cardiac Pacemaker, J . THORACIC & CARDIOVAS. SURG. 44: 617-627, 1962.
5. Boerema, T., and Bliekman, J . E . : Eeduced Intrathoracic Circulation as an Aid in Angio cardiography, J . THORACIC SURG. 30: 129-142, 1955.
6. Brofman, B . L., and Elder, J . C.: Cardioaortic Fistula: Temporary Circulatory Occlusion as an Aid in Diagnosis, Circulation 16: 77-86, 1957. 7. Di Guglielmo, L., and Guttadauro, M.: Eoentgenologic Visualization of the Coronary Ar teries in Living Subjects (413 Observations), Sc. med. ital. 3 : 446, 1955. 8. Dotter, C. T., and Frische, H . L . : Visualization of Coronary Circulation by Occlusion Aortography: A Practical Method, Eadiology 7 1 : 502, 1958. 9. Freeman, N . E., Fullenlove, T. M., Wylie, E . J., and Gilfillan, R. S.: The Valsalva Maneu ver: An Aid for the Contrast Visualization of the Aorta and Great Vessels, Ann. Surg. 130: 398, 1949. 10. Haight, C , Figley, M. M., Ellsworth, W. J., Sloan, H., Meyer, J . A., Berk, M. S., and Boblitt, D. E . : Experimental Coronary Arteriography: The Effects of Some Modifi cations of the Circulation, J . Surg. Ees. 2 : 7, 1962. 11. Hoyos, J . M., and del Campo, C. G.: Angiography of Thoracic Aorta and Coronary Ves sels, Eadiology 50: 211-213, 1948. 12. Lehman, J . S.: Coronary Arteriography: Practical Considerations, Progr. Cardiovas. Dis. 2: 36, 1959. 13. Nordenstrom B., Ovenfors, C. O., and Tbrnell, G.: Coronary Angiography in 100 Cases of Ischemic H e a r t Disease, Eadiology 78: 714-724, 1962. 14. Pampiglione, G., and Waterston, D. J . : EEG Observations During Changes in Venous and Arterial Pressure Cerebral Anoxia and the Electroencephalogram, edited by IT. Gastant, and J . S. Meyer, Springfield, 111., 1961, Charles C Thomas, Publisher, p. 250. 15. Perl, F . , Grey, N . N., and Friedman, B . : Retrograde Aortography With Special Catheter, Including Demonstration of Coronary Arteries, Ann. Surg. 132: 959-964, 1950.
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16. Radner, S.: An A t t e m p t a t the Roentgenologie Visualization of Coronary Blood Vessels in Man, Acta radiol. 26: 497, 1945. 17. Seldinger, S.: Catheter Replacement of the Needle in Percutaneous Arteriography, Acta radiol. 39: 368-376, 1963. 18. Sloan, H. E.: Discussion of Anlyan, W. G., et al.2 19. Sones, F. M., Jr., Shirky, E. K., Proudfit, W. L., and Westcoat, R. N . : Cine-Coronary Arteriography, Proceedings of the 32nd Annual Scientific Sessions, American Heart Association, p. 773, 1959. 20. Storm Van Leeuwen, W., and others: EEG During Heart Operations With Artificial Cir culation Cerebral Anoxia and the Electroencephalogram, edited by H. Gastaut, and J . S. Meyer, Springfield, 111., 1961, Charles C Thomas, Publisher, p. 268. 21. Thai, A. P . : The Clinical Usage of Coronary Arteriography, Angiology 12: 238, 1960. DISCUSSION DR. TIMOTHY TAKARO, Oteen, N. C—We have also been interested in visualizing the coronary tree. I n dogs, we have used a technique known to radiologists for several years but not yet applied to angiography; that is, the technique of direct roentgenographic mag nification, using the diverging rays from an ultra-fine focal spot tube, much in the manner of a magnifying glass. [Slide] The usual target-object-film relationships are altered so that the object (the heart in this instance) is placed halfway between the tube and the film. I n this angiogram of an animal one can see fine branches of the coronary arteries on the order of 100 micra in diameter, judging from the diameter of these wire vascular staples of 300 micra diameter here in the superior vena cava, at the same level as the coronary arteries. For clinical work we are going to need a much more powerful ultra-fine focal spot xray tube in order to apply this technique to patients. This is being built at present and we hope it will be powerful enough to magnify the coronary arteries of patients.