Annotations
an emergency situation, unintentional removal may have serious consequences. The great advantage of subclavian or internal jugular venepuncture is t h a t these veins remain p a t e n t under all clinical conditions, even in moribund patients of all ages. Despite claims for superiority of one established technique over the other in the past, the important factor is now known to be the care, experience, or degree of supervision of the operator. Clinicians with responsibilities in any type of acute medicine have an obligation to learn, and to maintain their proficiency with a technique for gaining rapid entry to a central vein, in any collapsed adult, child, or infant patient. Units possessing this expertise equally have an obligation to teach their chosen technique, without undue coercion, to selected responsible colleagues.
John WiUiamson, F.F.A.R.A.C.S. Department of Anaesthesia University Hospital Saskatoon, Saskatchewan Canada, S7N OW8 REFERENCES 1. Davidson, J. T., Ben-Hur, N., and Nathen, H: Subclavian venepuncture, Lancet 2:1139, 1963. 2. Yoffa, D.: Supraclavicular subclavian venepuncture and catheterisation, Lancet 2:614, 1965. 3. English, I. S. W., Frew, R. M., Piggott, J. F., and Zaki, M.: Percutaneous catheterisation of the internal jugular vein, Anaesthesiology 24:521, 1969. 4. Deitel, M., and MacIntyre, J. S.: Radiographic confirmation of the site of central venous pressure catheters, Can. J. Surg. 14:42, 1971. 5. McMahon, M. J.: Hazards of central venous catheterisation, Br. Med. J. 3:353, 1973.
6. 7. 8.
9. 10. 11. 12. 13. 14. 15.
16. 17. 18.
Swaroop, S.: Knotting of two central venous monitoring catheters, Am. J. Med. 53:386, 1972. Delfalque, R. J.: Fatal complication of subclavian catheter, Can. Anaes. Soc. J. 18:681, 1971. Brandt, R. L., Foley, W. J., Fink, G. H., and Regan, W. J.: Mechanism of perforation of the heart with production of hydropericardium by a venous catheter and its prevention, Am. 3. Surg. 119:311, 1970. Bone, D. K., Maddrey, W. C., Eagan, J., and Cameron, J. L.: Cardiac tamponade a fatal complication of central venous catheterisation, Arch: Surg. 106:868, t973. Williamson, J.: Complications of central venous catheterisation; Br. Med. J. 4:164, 1975. Adar, R., and Mozes, M.: Hydromediastinum, J.A.M.A. 214:372, 1970. Lumley, J., and Russell, W. J.: Insertion of central venous catheters through arm veins, Anaes. Intensive Care. 3:101, 1975. Greenall, M. J., Blewitt, R. W., and McMahon, M. J.: Cardiac tamponade and central venous catheters, Br. Med. J. 2:595, 1975. Delfalque, R. J.: Subclavian venepuncture. A review, Anesth. Aualg. 47:677, 1968. Arnold, S, Feathers, R. S., and Gibbs, E.: Bilateral pneumothoraces and subcutaneous emphysema: a complication of internal jugular venepuncture, Br. Med. J: 1:211, 1973. Bansmer, G., Keith, D., and Tesluk, H.: Complications following use of indwelling catheters of the inferior vena cava, J.A.M.A. 167:1606, 1958. Ng, W. S., and Rosen, M.: Positioning central venous catheters through the basilic vein, Br. J. Anaesth. 45:1211, 1973. Dudrick, S. J., Groff, D. B., and Wilmore, D. W.: Long term venous cathdterisation in infants, Sung. Gynecol. Obstet. 129:805, 1969.
Histochemical evaluation of myocardial preservation by local cooling during anoxia
Preservation of myocardial integrity during open-heart surgery is of utmost importance because the outcome of an otherwise successful operation may be disastrous if the myocardium is damaged. When a dry operative field is required and the aorta must be cross-clamped, selective coronary perfusion or some form of hypothermia has been utilized to protect the heart from the consequences of anoxia. Coronary perfusion, besides being sometimes technically difficult, has a large spectrum of complications, 1 and a n u m b e r of surgeons have been avoiding it by using varying periods of anoxia with hypothermia. No method, however, is fully satisfactory, and the subject continues to be a widely disputed issue in cardiac surgery. 2 A method introduced by Shumway and Lower, ~ involving local cooling of t h e heart b y a continuous flow of chilled saline through the pericardial sac, is attractive for both its simplicity and the advantages of
American Heart Journal
avoiding total-body hypothermia, and it has been gaining popularity. The evaluation of these methods has been one of the most difficult problems since control trials are obviously out of the question and the uncontrolled clinical comparisons are very hazardous because of the important influence on t h e outcome of the operation of so many other variables. Animal experiments have shed l i g h t on the mechanisms of myocardial damage dining open-heart surgery, 4 but t h e results are not directly applicable to the clinical situation. We reasoned t h a t if we were to study the preServation of the anoxic myocardium during local cooling, we should look for possible changes in cellular function occurringbetween the beginning and the end of the procedure. Extensive studies done by Niles and co-workers 5 have established t h a t histochemical techniques can be used as sensitive indices of altera-
669
Annotations
Table I. Grading of histochemical changes Case No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Procedure AVR* AVR AVR AVR AVR AVR AVR MVP* MVP MVP MVP MVP MVP MVP MVR* MVR MVR MVR MVR
(rain.)
Total score at start of bypass
Total score at end of bypass
Total score change
90 72 65 70 103 80 63 7 47 33 34 60 12 36 54 30 12 20 13
6.5 7 5 5.5 7.5 5 7.5 9 3.5 4 8 3.5 6.5 7 7.5 9 5.5 6.5 9
5 6.5 7.5 6 8 4 5.5 9 4 4.5 7.5 5 6.5 6.5 7 8 6.5 6.5 7
-1.5 -0.5 + 1.5 +0.5 + 0.5 -1 -2 0 + 0.5 + 0.5 -0.5 + 1.5 0 -0.5 -0.5 -1 +1 0 -1.5
Time of bypass
Time of aortic cross-clamping
(rain.) 120 97 112 117 168 101 98 52 80 110 95 107 i45 75 100 105 100 74 45
*AVR = Aortic valve replacement; MVR = mitral valve replacement; MVP = mitral valvulopiasty. tions in myocardial function. These have been successfully used at St. Thomas's Hospital, London, to predict postoperative function of the myocardium2' 7 The integrity of the cytoplasmic structure, energ~ production via oxidative mechanisms, and energy utilization for contraction of the myocardial cell can be assessed by the histochemical reactions of acid hematin, monoamine oxidase, Cytochrome oxidase, succinodehydroginase, and adenosine triphosphatase (ATPase). In 19 cases of aortic and mitral valve surgery done in Athens, utilizing anoxia and local pericardial cooling~ for the whole period of the bypass, samples of the left ventricular wall were obtained by drill biopsy at the beginning and end of the bypass. These were immediately chilled to - 7 0 ~ C. and sent to London, where the above histochemical tests were performed on frozen sections as described elsewhere.~, 9 The result was assessed by a single observer blind to the origin of the sample and was expressed in a semiquantitative way, grading the changes as follows: 0 = normal, 1 = fairly normal, 1 to 3 = moderate, 2 = poor, and 3 = bad. The total score o f each biopsy was a measure of the degree of myocardial cell damage. In Table I the total score is shown of the biopsies taken at the beginning and end of the operation. In the majority of cases the score either improved at the end of t h e operation Or deteriorated slightly. In three cases, however, increases of 1% in two cases and 3 in one case were noted, probably indicating a slight degree of myocardial damage. Changes in total score of similar magnitude in the direction of improvement, however, challenge the Validity of this statement, or these latter changes themselves require interpretation. Acid hematin reaction detects free phospholipids within the cytoplasm which are-probably liberated from the lipid-protein complexes of membranous structures, presumably following an insult. The monoamine oxidase and cytochrome oxidase
670
reactions relate to the integrity of the mitochondrial oxidative mechanisms which decrease under hypoxic conditions, whereas the succinodehydrogenase, an important enzyme of the Krebs cycle, is normally found uniformally distributed along the myofibrils. This has been thought to be related to a hydrogen-transporting system from mitochondria to myofibrils2 ~Finally, the ATPase activity in the cell is due to myocin itself, thus allowing detection of changes in the contractile system. Although these histochemical tests do assess a variety of aspects of cell functions, other important adverse changes may remain undetected. Neither does the detection of changes in the two different biopsies guarantee that they cannot be due to the sampling site or to an unforeseen difference in the technique. It is of interest, however, t h a t although there was a wide difference in the total score among the biopsies of the different patients taken at the beginning of the operation, there were much smaller differences seen between the beginning and the end. We concluded, therefore, that these results indicate good myocardial preservation by local cooling during bypass. In addition, quite serious changes may be present at the beginning of the bypass, due either to cardiac failure or possibly to the anesthesia and the operation up to that stage. Finally, in some cases slight deterioration and in some others slight improvement in myocardial function occurred during anoxia with local cooling. The last might presumably be due to the recovery of cellular integrity associated with the slowing down of biochemical activity during cooling. Apart from the obvious importance of these observations for the evaluation of local cooling during bypass, they raise the interesting possibility of a role of cooling in decreasing infarct size following a coronary attack. Unfortunately, there is no obvious way, in clinical myocardial infarction, of cooling the
N o v e m b e r , 1976, Vol. 92, No. 5
Annotahons
heart without the serious adverse effects of total-body hypothermia.
D. J. Viskos, M.D., F.A.C.S. N. B. Karatzas, M.D., D.Phil. Cardiosurgical Unit, Hippokrateion Hospital and Department of Medicine, University of A thens Greece M. V. Braimbridge, M.B., F.R.C.S. Sally Darracott Cardiothoracic Unit, St. Thomas' Hospital London England REFERENCES
1. Robicsek, F., Tam, W., Daugherty, H. K., and Mullen, D. C.: Myocardial protection during open-heart surgery: Coronary perfusion versus topical cardiac hypothermia, Ann. Thorac. Surg. 10:340, 1970. Maloney, J. V., Cooper, N., Mulder, D. G., and Buckberg, G. D.: Depressed cardiac performance after mitral valve replacement: A problem of myocardial preservation during operation, Circulation 51(Suppl. 1):1, 1974. Shumway, N. E., and Lower, R. R.: Topical cardiac hypothermia for extended periods of anoxic arrest, Surg. Forum 10:563, 1959.
4. Burdette, W. J., and Ashford, T. P.: Response of myocardial fine structure to cardiac arrest and hypothermia, Ann. Surg. 158:513, 1963. 5. Niles, N. R., Bitensky, L., Braimbridge, M. V., and Chayen, 3.: Histochemical changes related to oxidation and phosphorylation in human heart muscle, J. R. Microscop. Soc. 86:159, 1966. 6. Braimbridge, M. V., Darracott, S. A. R., Bitensky, L., and Chayen, J.: Cytochemical analysis of left ventricular biopsies in open-heart surgery: A pilot study, Beitr. Pathol. 148:255, 1973. 7. Braimbridge, M. V., Darracott, S., Clement, A. J., Bitensky, L., and Chayen, J.: Myocardial deterioration during aortic valve replacement assessed by cellular biological tests, J. Thorac. Cardiovasc. Surg. 66:241, 1973. 8. Hurley, E. J., Lower, R. R., Dong, E., Jr., Pillsbury, R, C., and Shumway, N. E.: Clinical experience with local hypothermia in elective cardiac arrest, J. Thorac. Cardiovasc. Surg. 47:50, 1964. 9. Chayen, J., Bitensky, L., Butcher, R., and Poulter, L.: A guide to practical histochemistry, Edinburgh, 1969, Oliver & Boyd, Ltd. 10. Chayen, J., Altmann, E. P., Bitensky, L., Braimbridge, M. V., Kadas, T., and Wells, P. J.: A study of the changes in hydrogen transport in an isolated rat heart preparation. J. R. Microscop. Soc. 86:151, 1966.
Now the treadmill!
When a diagnostic procedure necessitates the signing of a consent form by the patient, the immediate presence of an experienced physician, a defibrillator, and necessary drugs for care of cardiac arrest or other serious consequences, it must be a dangerous diagnostic procedure. Such is the case with the treadmill stress test. One then must ask, "Is such a procedure necessary?" "Is it ever needed?" "If so, when?" And, "What are the criteria for its indication?" Also, "If a serious accident or death were to occur as a result of the procedure, could the information that might be acquired justify subjecting the patient to. such a risk, even a fatal outcome?" With the treadmill, patients are tested "quantitatively" for cardiac function and potential function under physical stress to evaluate the state and capabilities of their coronary arteries for conducting blood flow. But, is it quantitative? Can a treadmill program be outlined which could be applied adequately to an 80-year-old lady who spends her life in a rocker at home and also to a 35-year-old jogger who runs 3 to 5 miles per day? Or, is a meticulously obtained history of such patients' responses to daily activity safer, more informative, and clinically more valuable in assessing coronary artery function? If a patient, prior to treatment, says he cannot walk two city blocks without chest pain, is his coronary arterial function known less or better than if he is tested on the treadmill? Is a treadmill test more accurate quantitatively than a meticulous history of the patient's responses to daily physical activity and psychic stress? After all, people live in homes, gardens, streets, offices, etc., and not on a moving treadmill surrounded by flashing lights, defibrillators, compli-
American Heart Journal
cated apparatus disgorging scrolls of paper, syringes, drugs, busy grim nurses and doctors in white. Furthermore. the hazardous treadmill test costs $100.00 or more. whereas the history of performance is routinely obtained by any welltrained conscientious cardiologist, anyway. Not many years ago, even cardiologists were reluctant to subject their patients to Master's 2-step test, a much milder and more appropriate test. Were they ~ight or wrong then? Did they miss something in the clinical cardiac study? With all of the new expensive and hazardous diagnostic and therapeutic procedures of today, is the life span of man being extended? Or. even the life span of one man? The H.E.W. Life Tables show slight to no increase in the life span of Americans for the past 20 years. 1 When the "books are balanced" with proper consideration of information derived from the treadmill test versus the expense, risk, damage, and even possible death associated with the test. is man "better off" with the treadmill or not? These questions must be answered. But who is to answer them? Who will outhne criteria for application of the test, be responsible for serious reactions, and control costs? The patient is usually impressed with the procedure, but he is in no position to understand or know the indication, value, or risks involved. Initially, the treadmil] was used only in the hospital where "adequate" facilities were available to manage properly any adverse responses to the exercise test. including cardiac arrest. Now, the treadmill is being employed in the physician's office. So, now, the treadmill! What next? Can anything be admitted into the practice of medicine and be accepted
671
an emergency situation, unintentional removal may have serious consequences. The great advantage of subclavian or internal jugular venepuncture is t h a t these veins remain p a t e n t under all clinical conditions, even in moribund patients of all ages. Despite claims for superiority of one established technique over the other in the past, the important factor is now known to be the care, experience, or degree of supervision of the operator. Clinicians with responsibilities in any type of acute medicine have an obligation to learn, and to maintain their proficiency with a technique for gaining rapid entry to a central vein, in any collapsed adult, child, or infant patient. Units possessing this expertise equally have an obligation to teach their chosen technique, without undue coercion, to selected responsible colleagues.
John WiUiamson, F.F.A.R.A.C.S. Department of Anaesthesia University Hospital Saskatoon, Saskatchewan Canada, S7N OW8 REFERENCES 1. Davidson, J. T., Ben-Hur, N., and Nathen, H: Subclavian venepuncture, Lancet 2:1139, 1963. 2. Yoffa, D.: Supraclavicular subclavian venepuncture and catheterisation, Lancet 2:614, 1965. 3. English, I. S. W., Frew, R. M., Piggott, J. F., and Zaki, M.: Percutaneous catheterisation of the internal jugular vein, Anaesthesiology 24:521, 1969. 4. Deitel, M., and MacIntyre, J. S.: Radiographic confirmation of the site of central venous pressure catheters, Can. J. Surg. 14:42, 1971. 5. McMahon, M. J.: Hazards of central venous catheterisation, Br. Med. J. 3:353, 1973.
6. 7. 8.
9. 10. 11. 12. 13. 14. 15.
16. 17. 18.
Swaroop, S.: Knotting of two central venous monitoring catheters, Am. J. Med. 53:386, 1972. Delfalque, R. J.: Fatal complication of subclavian catheter, Can. Anaes. Soc. J. 18:681, 1971. Brandt, R. L., Foley, W. J., Fink, G. H., and Regan, W. J.: Mechanism of perforation of the heart with production of hydropericardium by a venous catheter and its prevention, Am. 3. Surg. 119:311, 1970. Bone, D. K., Maddrey, W. C., Eagan, J., and Cameron, J. L.: Cardiac tamponade a fatal complication of central venous catheterisation, Arch: Surg. 106:868, t973. Williamson, J.: Complications of central venous catheterisation; Br. Med. J. 4:164, 1975. Adar, R., and Mozes, M.: Hydromediastinum, J.A.M.A. 214:372, 1970. Lumley, J., and Russell, W. J.: Insertion of central venous catheters through arm veins, Anaes. Intensive Care. 3:101, 1975. Greenall, M. J., Blewitt, R. W., and McMahon, M. J.: Cardiac tamponade and central venous catheters, Br. Med. J. 2:595, 1975. Delfalque, R. J.: Subclavian venepuncture. A review, Anesth. Aualg. 47:677, 1968. Arnold, S, Feathers, R. S., and Gibbs, E.: Bilateral pneumothoraces and subcutaneous emphysema: a complication of internal jugular venepuncture, Br. Med. J: 1:211, 1973. Bansmer, G., Keith, D., and Tesluk, H.: Complications following use of indwelling catheters of the inferior vena cava, J.A.M.A. 167:1606, 1958. Ng, W. S., and Rosen, M.: Positioning central venous catheters through the basilic vein, Br. J. Anaesth. 45:1211, 1973. Dudrick, S. J., Groff, D. B., and Wilmore, D. W.: Long term venous cathdterisation in infants, Sung. Gynecol. Obstet. 129:805, 1969.
Histochemical evaluation of myocardial preservation by local cooling during anoxia
Preservation of myocardial integrity during open-heart surgery is of utmost importance because the outcome of an otherwise successful operation may be disastrous if the myocardium is damaged. When a dry operative field is required and the aorta must be cross-clamped, selective coronary perfusion or some form of hypothermia has been utilized to protect the heart from the consequences of anoxia. Coronary perfusion, besides being sometimes technically difficult, has a large spectrum of complications, 1 and a n u m b e r of surgeons have been avoiding it by using varying periods of anoxia with hypothermia. No method, however, is fully satisfactory, and the subject continues to be a widely disputed issue in cardiac surgery. 2 A method introduced by Shumway and Lower, ~ involving local cooling of t h e heart b y a continuous flow of chilled saline through the pericardial sac, is attractive for both its simplicity and the advantages of
American Heart Journal
avoiding total-body hypothermia, and it has been gaining popularity. The evaluation of these methods has been one of the most difficult problems since control trials are obviously out of the question and the uncontrolled clinical comparisons are very hazardous because of the important influence on t h e outcome of the operation of so many other variables. Animal experiments have shed l i g h t on the mechanisms of myocardial damage dining open-heart surgery, 4 but t h e results are not directly applicable to the clinical situation. We reasoned t h a t if we were to study the preServation of the anoxic myocardium during local cooling, we should look for possible changes in cellular function occurringbetween the beginning and the end of the procedure. Extensive studies done by Niles and co-workers 5 have established t h a t histochemical techniques can be used as sensitive indices of altera-
669
Annotations
Table I. Grading of histochemical changes Case No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Procedure AVR* AVR AVR AVR AVR AVR AVR MVP* MVP MVP MVP MVP MVP MVP MVR* MVR MVR MVR MVR
(rain.)
Total score at start of bypass
Total score at end of bypass
Total score change
90 72 65 70 103 80 63 7 47 33 34 60 12 36 54 30 12 20 13
6.5 7 5 5.5 7.5 5 7.5 9 3.5 4 8 3.5 6.5 7 7.5 9 5.5 6.5 9
5 6.5 7.5 6 8 4 5.5 9 4 4.5 7.5 5 6.5 6.5 7 8 6.5 6.5 7
-1.5 -0.5 + 1.5 +0.5 + 0.5 -1 -2 0 + 0.5 + 0.5 -0.5 + 1.5 0 -0.5 -0.5 -1 +1 0 -1.5
Time of bypass
Time of aortic cross-clamping
(rain.) 120 97 112 117 168 101 98 52 80 110 95 107 i45 75 100 105 100 74 45
*AVR = Aortic valve replacement; MVR = mitral valve replacement; MVP = mitral valvulopiasty. tions in myocardial function. These have been successfully used at St. Thomas's Hospital, London, to predict postoperative function of the myocardium2' 7 The integrity of the cytoplasmic structure, energ~ production via oxidative mechanisms, and energy utilization for contraction of the myocardial cell can be assessed by the histochemical reactions of acid hematin, monoamine oxidase, Cytochrome oxidase, succinodehydroginase, and adenosine triphosphatase (ATPase). In 19 cases of aortic and mitral valve surgery done in Athens, utilizing anoxia and local pericardial cooling~ for the whole period of the bypass, samples of the left ventricular wall were obtained by drill biopsy at the beginning and end of the bypass. These were immediately chilled to - 7 0 ~ C. and sent to London, where the above histochemical tests were performed on frozen sections as described elsewhere.~, 9 The result was assessed by a single observer blind to the origin of the sample and was expressed in a semiquantitative way, grading the changes as follows: 0 = normal, 1 = fairly normal, 1 to 3 = moderate, 2 = poor, and 3 = bad. The total score o f each biopsy was a measure of the degree of myocardial cell damage. In Table I the total score is shown of the biopsies taken at the beginning and end of the operation. In the majority of cases the score either improved at the end of t h e operation Or deteriorated slightly. In three cases, however, increases of 1% in two cases and 3 in one case were noted, probably indicating a slight degree of myocardial damage. Changes in total score of similar magnitude in the direction of improvement, however, challenge the Validity of this statement, or these latter changes themselves require interpretation. Acid hematin reaction detects free phospholipids within the cytoplasm which are-probably liberated from the lipid-protein complexes of membranous structures, presumably following an insult. The monoamine oxidase and cytochrome oxidase
670
reactions relate to the integrity of the mitochondrial oxidative mechanisms which decrease under hypoxic conditions, whereas the succinodehydrogenase, an important enzyme of the Krebs cycle, is normally found uniformally distributed along the myofibrils. This has been thought to be related to a hydrogen-transporting system from mitochondria to myofibrils2 ~Finally, the ATPase activity in the cell is due to myocin itself, thus allowing detection of changes in the contractile system. Although these histochemical tests do assess a variety of aspects of cell functions, other important adverse changes may remain undetected. Neither does the detection of changes in the two different biopsies guarantee that they cannot be due to the sampling site or to an unforeseen difference in the technique. It is of interest, however, t h a t although there was a wide difference in the total score among the biopsies of the different patients taken at the beginning of the operation, there were much smaller differences seen between the beginning and the end. We concluded, therefore, that these results indicate good myocardial preservation by local cooling during bypass. In addition, quite serious changes may be present at the beginning of the bypass, due either to cardiac failure or possibly to the anesthesia and the operation up to that stage. Finally, in some cases slight deterioration and in some others slight improvement in myocardial function occurred during anoxia with local cooling. The last might presumably be due to the recovery of cellular integrity associated with the slowing down of biochemical activity during cooling. Apart from the obvious importance of these observations for the evaluation of local cooling during bypass, they raise the interesting possibility of a role of cooling in decreasing infarct size following a coronary attack. Unfortunately, there is no obvious way, in clinical myocardial infarction, of cooling the
N o v e m b e r , 1976, Vol. 92, No. 5
Annotahons
heart without the serious adverse effects of total-body hypothermia.
D. J. Viskos, M.D., F.A.C.S. N. B. Karatzas, M.D., D.Phil. Cardiosurgical Unit, Hippokrateion Hospital and Department of Medicine, University of A thens Greece M. V. Braimbridge, M.B., F.R.C.S. Sally Darracott Cardiothoracic Unit, St. Thomas' Hospital London England REFERENCES
1. Robicsek, F., Tam, W., Daugherty, H. K., and Mullen, D. C.: Myocardial protection during open-heart surgery: Coronary perfusion versus topical cardiac hypothermia, Ann. Thorac. Surg. 10:340, 1970. Maloney, J. V., Cooper, N., Mulder, D. G., and Buckberg, G. D.: Depressed cardiac performance after mitral valve replacement: A problem of myocardial preservation during operation, Circulation 51(Suppl. 1):1, 1974. Shumway, N. E., and Lower, R. R.: Topical cardiac hypothermia for extended periods of anoxic arrest, Surg. Forum 10:563, 1959.
4. Burdette, W. J., and Ashford, T. P.: Response of myocardial fine structure to cardiac arrest and hypothermia, Ann. Surg. 158:513, 1963. 5. Niles, N. R., Bitensky, L., Braimbridge, M. V., and Chayen, 3.: Histochemical changes related to oxidation and phosphorylation in human heart muscle, J. R. Microscop. Soc. 86:159, 1966. 6. Braimbridge, M. V., Darracott, S. A. R., Bitensky, L., and Chayen, J.: Cytochemical analysis of left ventricular biopsies in open-heart surgery: A pilot study, Beitr. Pathol. 148:255, 1973. 7. Braimbridge, M. V., Darracott, S., Clement, A. J., Bitensky, L., and Chayen, J.: Myocardial deterioration during aortic valve replacement assessed by cellular biological tests, J. Thorac. Cardiovasc. Surg. 66:241, 1973. 8. Hurley, E. J., Lower, R. R., Dong, E., Jr., Pillsbury, R, C., and Shumway, N. E.: Clinical experience with local hypothermia in elective cardiac arrest, J. Thorac. Cardiovasc. Surg. 47:50, 1964. 9. Chayen, J., Bitensky, L., Butcher, R., and Poulter, L.: A guide to practical histochemistry, Edinburgh, 1969, Oliver & Boyd, Ltd. 10. Chayen, J., Altmann, E. P., Bitensky, L., Braimbridge, M. V., Kadas, T., and Wells, P. J.: A study of the changes in hydrogen transport in an isolated rat heart preparation. J. R. Microscop. Soc. 86:151, 1966.
Now the treadmill!
When a diagnostic procedure necessitates the signing of a consent form by the patient, the immediate presence of an experienced physician, a defibrillator, and necessary drugs for care of cardiac arrest or other serious consequences, it must be a dangerous diagnostic procedure. Such is the case with the treadmill stress test. One then must ask, "Is such a procedure necessary?" "Is it ever needed?" "If so, when?" And, "What are the criteria for its indication?" Also, "If a serious accident or death were to occur as a result of the procedure, could the information that might be acquired justify subjecting the patient to. such a risk, even a fatal outcome?" With the treadmill, patients are tested "quantitatively" for cardiac function and potential function under physical stress to evaluate the state and capabilities of their coronary arteries for conducting blood flow. But, is it quantitative? Can a treadmill program be outlined which could be applied adequately to an 80-year-old lady who spends her life in a rocker at home and also to a 35-year-old jogger who runs 3 to 5 miles per day? Or, is a meticulously obtained history of such patients' responses to daily activity safer, more informative, and clinically more valuable in assessing coronary artery function? If a patient, prior to treatment, says he cannot walk two city blocks without chest pain, is his coronary arterial function known less or better than if he is tested on the treadmill? Is a treadmill test more accurate quantitatively than a meticulous history of the patient's responses to daily physical activity and psychic stress? After all, people live in homes, gardens, streets, offices, etc., and not on a moving treadmill surrounded by flashing lights, defibrillators, compli-
American Heart Journal
cated apparatus disgorging scrolls of paper, syringes, drugs, busy grim nurses and doctors in white. Furthermore. the hazardous treadmill test costs $100.00 or more. whereas the history of performance is routinely obtained by any welltrained conscientious cardiologist, anyway. Not many years ago, even cardiologists were reluctant to subject their patients to Master's 2-step test, a much milder and more appropriate test. Were they ~ight or wrong then? Did they miss something in the clinical cardiac study? With all of the new expensive and hazardous diagnostic and therapeutic procedures of today, is the life span of man being extended? Or. even the life span of one man? The H.E.W. Life Tables show slight to no increase in the life span of Americans for the past 20 years. 1 When the "books are balanced" with proper consideration of information derived from the treadmill test versus the expense, risk, damage, and even possible death associated with the test. is man "better off" with the treadmill or not? These questions must be answered. But who is to answer them? Who will outhne criteria for application of the test, be responsible for serious reactions, and control costs? The patient is usually impressed with the procedure, but he is in no position to understand or know the indication, value, or risks involved. Initially, the treadmil] was used only in the hospital where "adequate" facilities were available to manage properly any adverse responses to the exercise test. including cardiac arrest. Now, the treadmill is being employed in the physician's office. So, now, the treadmill! What next? Can anything be admitted into the practice of medicine and be accepted
671
