Letters to the Editor
Exercise--hazard or health aid To the Editor: The idea t h a t one type of exercise is beneficial and another harmful may appear mystical to Dr. Eskwith 1 b u t there is scientific evidence this may be true. I refer you to Dr. Joel Morganroth's report on two types of athletic heart2: the diastolic heart of the distance r u n n e r and the systolic heart of the weightlifter and shotputter. We distance runners naturally look on the diastolic h e a r t as the one to have. But then we do tend to be mystics. George A. Sheehan, M.D. 79 W e s t Front St. Red Bank, N. J. 07701
REFERENCES 1. Eskwith, I. S.: Reply (Letter to Editor), Am. Heart J. 92:267, 1976. 2. Morganroth, J., et al.: Comparative left ventricular dimensions in trained athletes, Ann. Intern. Med. 82:521, 1975.
W h a t kind of evidence? To the Editor: In the August, 1976, issue of the JOURNAL Eskwith, 1 in reply to a letter, writes the following: "Circumstantial evidence, no matter how strong, has no place in scientific discipline and cannot be substituted for proof, neither can anecdotal reports. ''1 He considers his correspondent's contention t h a t one type of exercise can be beneficial, another harmful, "too mystic a concept" to be believable. In this connection it may be useful to ask, what kind of evidence is acceptable to science? It is clear t h a t data can be misinterpreted and medicine, like any other branch of science, provides ample scope for h u m a n error. Equally clearly, generalizations and hypotheses should be carefully scrutinized before they gain acceptance. As there is only one basic faculty of h u m a n reasoning, the scientist has no other mental equipment at his disposal t h a n anyone else. He differs only in the more disciplined use of this faculty, imposed on him by more rigorous criteria of what constitutes acceptable evidence of validity. Generalizations based on a few examples, to which the vogue term "anecdotal" presumably applies, belong to the genus of statistics derived from an insufficient n u m b e r of samples. They can doubtless be sources of error. An amusing example is cited by Gordon, 2 writing of a Russian report to the effect t h a t the incidence of heart disease was higher among the staff of a Moscow Institute of Food t h a n in an Institute of Geology. While on the subject of possible sources of error, may I mention another example? This is the often ignored uncertainty, when the results of animal trials are applied to h u m a n practice. An example is the classic experiment in 1913 of Anitchkow and Chalatow, who were the first to produce atheroma-like lesions in cholesterol-fed rabbits. The source of
American Heart Journal
error in this case is t h a t some mammals, including man, possess a mechanism regulating the absorption of dietarY cholesterol, enabling them to reject excess intake Undigested, while some herbivores, like rabbits, do not. T h e presumable reason is t h a t plants contain little cholesterol, so t h a t ' t h e ingestion of a quantity in excess of needs is so unlikely for a herbivore under natural conditions, t h a t a mechanism capable of rejecting such excesses has no survival value for them. The lack of this information in the earlier decades of the present century has led to the ill-founded but widely accepted belief t h a t excess cholesterol in the diet was the main cause of h u m a n atheroma. However, it is possible to err in two directions. In science, insistence on too rigorous criteria of validity can have a stifling effect. Non-communicable diseases, like cancer, atheroma or multiple sclerosis, seldom oblige us by providing easily recognizable clues for their etiology and pathogenesis, so who is to provide those perfect, incontrovertible, scientifically acceptable hypotheses? Since beginnings have to be made somewhere, most probably imperfect beginnings, is it not the case of cutting our coats to fit our cloth? Insistence on perfection is likely to result in scientists refraining from attempting the impossible and keeping to data-collecting and fact-finding. The worst example in this respect is cancer research, with its flood of literature on experiments with inbred, x-ray irradiated, cortisone-treated rats. Most of these experiments are probably irrelevant to any aspect of h u m a n cancer and most are probably of the nature of trying to find out how a motorcar worked by experimenting on it, e.g., by drilling holes in its hood or by mixing chicken blood with its gasoline. While such experiments are impeccably scientific in form, they are utterly sterile and unproductive in practice. Perhaps the best judgment on them, to quote Gordon again: "seldom can so much have been written by so many and read by so few. ''2 In my opinion the only practicable criterion of validity ever produced by science is t h a t of consistency. A deduction or generalization derived from one set of data is tentatively regarded valid if it is consistent with similar deductions or generalizations based on another set of data and is finally incorporated in the tenets of science unless later challenged by new observations. This is how science does, in fact, progress. The progress may be halting and jerky, but, in the long run, it is progress. Let us consider, how all this applies to the subject of Dr. Eskwith's letter. In my opinion any evidence relevant to a problem is admissible and cannot be rejected by catchwords like "circumstantial" or "anecdotal." T h e replier should take the trouble to explain why a thesis is unacceptable, t h a t is, provide data which contradict it or with which the thesis is inconsistent. I do not agree t h a t the proposition t h a t some exercise can be beneficial, other harmful, is obviously wrong. Sudden bursts of violent exercise could be harmful, because they are likely to find any weakness of the circulatory system. Sedentary life can conceivably be harmful because never used capillaries and arterioles may disappear, which may mean the difference between death and survival i n an emergency following the
537
Letters to the Editor
occlusion of an artery in the coronary circulation. Moderate, regular exercise may steer a median course between the two evils.
Stephen Seely, B.Sc. 3 Truro Drive, Sale, Cheshire M33 5DF, England
REFERENCES 1. Eskwith, I. S.: Reply (Letter to Editor), AM. HEART J. 92:267, 1976. 2. Gordon, I.: Cholesterophobia, 1962, Medical Officer, 108:385, 1962.
Reply To the Editor: I now find myself answering letters written to the reply of my original communication to your JOURNAL. In reference to Doctor Sheehan's letter, perhaps long distance runners have a lower mortality from heart disease, perhaps not. They form a very small group. Regardless of what their mortality is, I can't see the general population getting up every morning and running twenty miles before reporting to work. I don't think we should be too sanguine about this small group of people until more data have been compiled on them. Doctor Seely's letter is most interesting. To my mind, objective evidence in connection with atherosclerotic heart disease would be the application of a remedy which by itself produces a sharp and sustained reduction in mortality from heart disease. An example of such objective evidence would be the mortality from subacute bacterial endocarditis prior to the use of penicillin therapy and afterwards. Koch's Postulates still remain excellent guidelines for determining what objective criteria are. It is apparently not considered stylish to read them anymore, but I think we all should, for they are as valid today as when they were originally written. These furnish a good skeleton on which to construct any experiment t h a t would have in mind the reduction of heart disease. Naturally, as a writer, even of a letter, I have been very pleased at the response my original note has elicited. Ventilation of controversy, particularly in areas t h a t are themselves controversial, is always beneficial and stimulating.
Irwin S. Eskwith, M.D. Pinnell Street Ripley, W. Va. 25271
The simultaneous occurrence of a ventricular septal defect and mitral insufficiency after myocardial infarction To the Editor: It is of interest to note the rarity of simultaneous occurrence of ventricular septal defect and mitral regurgitation complicating myocardial infarction. Doctors Gowda, Loh, and Roberts (AM. HEART J. 92:234, 1976) remarked "it is possible t h a t surgery may be helpful when both lesions are present, if recovery is possible for 2 to 3 weeks." The following report demonstrates the success of surgery in such a case.
Case report A 6!-year-old white male was admitted to the coronary care unit of the V. A. Hospital, Salem, Va., on April 2, 1974, with the complaints of shortness of breath and ankle swelling. He 538
had been in his usual good health until two weeks prior to his admission when he developed vague chest pain and shortness of breath. He consulted his family physician who prescribed some medicine but his symptoms continued to get worse and he had shortness of breath on mild activity,, orthopnea, paroxysmal nocturnal dyspnea, and swelling of his legs at the time of admission to the V. A. Hospital. He smoked one pack of cigarettes per day and had some cough and mild dyspnea of effort in the past. He did not have hypertension, diabetes mellitus, or angina pectoris. His only previous admission to the hospital was in 1973 for bunionectomy. Physical examination revealed an ill-looking m a n in respiratory discomfort. His pulse was 100' per m i n u t e in regular rhythm. Blood pressure was 95/50 mm. Hg. The neck veins were distended up to the angle of jaw with prominent "V" waves at 45 degrees inclination. The point of maximal impulse of the heart was in the anterior axillary line in the fifth left intercostal space (LICS). No thrills were palpable. There was a summation gallop, pericardial friction ~rub, and 3/6 pansystolic murmur. The m u r m u r was heard maximally in the fourth LICS along the parasternal border but radiated to the apex and the axilla. Bibasilar rfiles were present up to the angle of the scapulae. The liver was tender and was enlarged two fingerbreadths below the costal margin. There was pitting edema of the lower legs and sacral area. X-ray of the chest showed cardiomegaly, congestion of pulmonary vessels, and left ventricular failure. The electrocardiogram revealed regular sinus r h y t h m with Q wave, ST elevation, and T wave inversion in Leads 2, 3, aVF and T wave inversion in Leads V~_8. Laboratory findings were: SGOT 345 units, S L D H 1096 units, and CPK 21 units. Hematocrit was 37 per cent and white blood cell count 7800/mm2 He was treated with intravenous furosemide, salt and fluid restriction, and digoxin. He had a good diuretic response and had subjective and objective improvement, but 36 hours after admission he became cyanotic and had no palpable pulses. He remained in sinus rhythm. Cardiopulmonary resuscitation was immediately initiated and pericardiocentesis was a t t e m p t e d b u t did not yield any fluid. Norepinephrine infusion raised the systolic blood pressure to 100 mm. Hg and One h o u r later he was able to maintain blood pressure on his own. He was transferred to the University of Virginia Medical Center, Charlottesville, Virginia. Cardiac catheterization and coronary angiography were performed. These showed elevated right atrial pressure with "a" waves of 11, "v" waves of 12, and a mean pressure of 9 mm. Hg. Right ventricular and pulmonary artery pressures were 40/11 and 40/16 mm. Hg, respectively. P u l m o n a r y capillary wedge pressure was also elevated a n d showed "a" and "v" waves of 16 and 21 mm. Hg. T h e r e was a positive hydrogen curve in the pulmonary artery. Pulmonary-tosystemic blood flow ratio was 1.3 and a left-to-right s h u n t of 0.64 L./min./M. ~ Left ventricular end-diastolic pressure was elevated at 22 mm. Hg. Left ventricular angiography showed 2 to 3 + mitral regurgitation, akinesis of a large portion of inferior wall, and a discreet inferior wall aneurysm just beneath the posterior medial papillary muscle. Right coronary artery (RCA) cineangiography revealed the RCA to be the dominant coronary artery with complete occlusion in its proximal portion. Both left anterior descending and left circumflex coronary arteries showed 50 per cent occlusion with poor distal vessels. The next day he developed Mobitz II heart block and a temporary transvenous pacemaker was inserted.
October, 1977, Vol. 94, No. 4
Exercise--hazard or health aid To the Editor: The idea t h a t one type of exercise is beneficial and another harmful may appear mystical to Dr. Eskwith 1 b u t there is scientific evidence this may be true. I refer you to Dr. Joel Morganroth's report on two types of athletic heart2: the diastolic heart of the distance r u n n e r and the systolic heart of the weightlifter and shotputter. We distance runners naturally look on the diastolic h e a r t as the one to have. But then we do tend to be mystics. George A. Sheehan, M.D. 79 W e s t Front St. Red Bank, N. J. 07701
REFERENCES 1. Eskwith, I. S.: Reply (Letter to Editor), Am. Heart J. 92:267, 1976. 2. Morganroth, J., et al.: Comparative left ventricular dimensions in trained athletes, Ann. Intern. Med. 82:521, 1975.
W h a t kind of evidence? To the Editor: In the August, 1976, issue of the JOURNAL Eskwith, 1 in reply to a letter, writes the following: "Circumstantial evidence, no matter how strong, has no place in scientific discipline and cannot be substituted for proof, neither can anecdotal reports. ''1 He considers his correspondent's contention t h a t one type of exercise can be beneficial, another harmful, "too mystic a concept" to be believable. In this connection it may be useful to ask, what kind of evidence is acceptable to science? It is clear t h a t data can be misinterpreted and medicine, like any other branch of science, provides ample scope for h u m a n error. Equally clearly, generalizations and hypotheses should be carefully scrutinized before they gain acceptance. As there is only one basic faculty of h u m a n reasoning, the scientist has no other mental equipment at his disposal t h a n anyone else. He differs only in the more disciplined use of this faculty, imposed on him by more rigorous criteria of what constitutes acceptable evidence of validity. Generalizations based on a few examples, to which the vogue term "anecdotal" presumably applies, belong to the genus of statistics derived from an insufficient n u m b e r of samples. They can doubtless be sources of error. An amusing example is cited by Gordon, 2 writing of a Russian report to the effect t h a t the incidence of heart disease was higher among the staff of a Moscow Institute of Food t h a n in an Institute of Geology. While on the subject of possible sources of error, may I mention another example? This is the often ignored uncertainty, when the results of animal trials are applied to h u m a n practice. An example is the classic experiment in 1913 of Anitchkow and Chalatow, who were the first to produce atheroma-like lesions in cholesterol-fed rabbits. The source of
American Heart Journal
error in this case is t h a t some mammals, including man, possess a mechanism regulating the absorption of dietarY cholesterol, enabling them to reject excess intake Undigested, while some herbivores, like rabbits, do not. T h e presumable reason is t h a t plants contain little cholesterol, so t h a t ' t h e ingestion of a quantity in excess of needs is so unlikely for a herbivore under natural conditions, t h a t a mechanism capable of rejecting such excesses has no survival value for them. The lack of this information in the earlier decades of the present century has led to the ill-founded but widely accepted belief t h a t excess cholesterol in the diet was the main cause of h u m a n atheroma. However, it is possible to err in two directions. In science, insistence on too rigorous criteria of validity can have a stifling effect. Non-communicable diseases, like cancer, atheroma or multiple sclerosis, seldom oblige us by providing easily recognizable clues for their etiology and pathogenesis, so who is to provide those perfect, incontrovertible, scientifically acceptable hypotheses? Since beginnings have to be made somewhere, most probably imperfect beginnings, is it not the case of cutting our coats to fit our cloth? Insistence on perfection is likely to result in scientists refraining from attempting the impossible and keeping to data-collecting and fact-finding. The worst example in this respect is cancer research, with its flood of literature on experiments with inbred, x-ray irradiated, cortisone-treated rats. Most of these experiments are probably irrelevant to any aspect of h u m a n cancer and most are probably of the nature of trying to find out how a motorcar worked by experimenting on it, e.g., by drilling holes in its hood or by mixing chicken blood with its gasoline. While such experiments are impeccably scientific in form, they are utterly sterile and unproductive in practice. Perhaps the best judgment on them, to quote Gordon again: "seldom can so much have been written by so many and read by so few. ''2 In my opinion the only practicable criterion of validity ever produced by science is t h a t of consistency. A deduction or generalization derived from one set of data is tentatively regarded valid if it is consistent with similar deductions or generalizations based on another set of data and is finally incorporated in the tenets of science unless later challenged by new observations. This is how science does, in fact, progress. The progress may be halting and jerky, but, in the long run, it is progress. Let us consider, how all this applies to the subject of Dr. Eskwith's letter. In my opinion any evidence relevant to a problem is admissible and cannot be rejected by catchwords like "circumstantial" or "anecdotal." T h e replier should take the trouble to explain why a thesis is unacceptable, t h a t is, provide data which contradict it or with which the thesis is inconsistent. I do not agree t h a t the proposition t h a t some exercise can be beneficial, other harmful, is obviously wrong. Sudden bursts of violent exercise could be harmful, because they are likely to find any weakness of the circulatory system. Sedentary life can conceivably be harmful because never used capillaries and arterioles may disappear, which may mean the difference between death and survival i n an emergency following the
537
Letters to the Editor
occlusion of an artery in the coronary circulation. Moderate, regular exercise may steer a median course between the two evils.
Stephen Seely, B.Sc. 3 Truro Drive, Sale, Cheshire M33 5DF, England
REFERENCES 1. Eskwith, I. S.: Reply (Letter to Editor), AM. HEART J. 92:267, 1976. 2. Gordon, I.: Cholesterophobia, 1962, Medical Officer, 108:385, 1962.
Reply To the Editor: I now find myself answering letters written to the reply of my original communication to your JOURNAL. In reference to Doctor Sheehan's letter, perhaps long distance runners have a lower mortality from heart disease, perhaps not. They form a very small group. Regardless of what their mortality is, I can't see the general population getting up every morning and running twenty miles before reporting to work. I don't think we should be too sanguine about this small group of people until more data have been compiled on them. Doctor Seely's letter is most interesting. To my mind, objective evidence in connection with atherosclerotic heart disease would be the application of a remedy which by itself produces a sharp and sustained reduction in mortality from heart disease. An example of such objective evidence would be the mortality from subacute bacterial endocarditis prior to the use of penicillin therapy and afterwards. Koch's Postulates still remain excellent guidelines for determining what objective criteria are. It is apparently not considered stylish to read them anymore, but I think we all should, for they are as valid today as when they were originally written. These furnish a good skeleton on which to construct any experiment t h a t would have in mind the reduction of heart disease. Naturally, as a writer, even of a letter, I have been very pleased at the response my original note has elicited. Ventilation of controversy, particularly in areas t h a t are themselves controversial, is always beneficial and stimulating.
Irwin S. Eskwith, M.D. Pinnell Street Ripley, W. Va. 25271
The simultaneous occurrence of a ventricular septal defect and mitral insufficiency after myocardial infarction To the Editor: It is of interest to note the rarity of simultaneous occurrence of ventricular septal defect and mitral regurgitation complicating myocardial infarction. Doctors Gowda, Loh, and Roberts (AM. HEART J. 92:234, 1976) remarked "it is possible t h a t surgery may be helpful when both lesions are present, if recovery is possible for 2 to 3 weeks." The following report demonstrates the success of surgery in such a case.
Case report A 6!-year-old white male was admitted to the coronary care unit of the V. A. Hospital, Salem, Va., on April 2, 1974, with the complaints of shortness of breath and ankle swelling. He 538
had been in his usual good health until two weeks prior to his admission when he developed vague chest pain and shortness of breath. He consulted his family physician who prescribed some medicine but his symptoms continued to get worse and he had shortness of breath on mild activity,, orthopnea, paroxysmal nocturnal dyspnea, and swelling of his legs at the time of admission to the V. A. Hospital. He smoked one pack of cigarettes per day and had some cough and mild dyspnea of effort in the past. He did not have hypertension, diabetes mellitus, or angina pectoris. His only previous admission to the hospital was in 1973 for bunionectomy. Physical examination revealed an ill-looking m a n in respiratory discomfort. His pulse was 100' per m i n u t e in regular rhythm. Blood pressure was 95/50 mm. Hg. The neck veins were distended up to the angle of jaw with prominent "V" waves at 45 degrees inclination. The point of maximal impulse of the heart was in the anterior axillary line in the fifth left intercostal space (LICS). No thrills were palpable. There was a summation gallop, pericardial friction ~rub, and 3/6 pansystolic murmur. The m u r m u r was heard maximally in the fourth LICS along the parasternal border but radiated to the apex and the axilla. Bibasilar rfiles were present up to the angle of the scapulae. The liver was tender and was enlarged two fingerbreadths below the costal margin. There was pitting edema of the lower legs and sacral area. X-ray of the chest showed cardiomegaly, congestion of pulmonary vessels, and left ventricular failure. The electrocardiogram revealed regular sinus r h y t h m with Q wave, ST elevation, and T wave inversion in Leads 2, 3, aVF and T wave inversion in Leads V~_8. Laboratory findings were: SGOT 345 units, S L D H 1096 units, and CPK 21 units. Hematocrit was 37 per cent and white blood cell count 7800/mm2 He was treated with intravenous furosemide, salt and fluid restriction, and digoxin. He had a good diuretic response and had subjective and objective improvement, but 36 hours after admission he became cyanotic and had no palpable pulses. He remained in sinus rhythm. Cardiopulmonary resuscitation was immediately initiated and pericardiocentesis was a t t e m p t e d b u t did not yield any fluid. Norepinephrine infusion raised the systolic blood pressure to 100 mm. Hg and One h o u r later he was able to maintain blood pressure on his own. He was transferred to the University of Virginia Medical Center, Charlottesville, Virginia. Cardiac catheterization and coronary angiography were performed. These showed elevated right atrial pressure with "a" waves of 11, "v" waves of 12, and a mean pressure of 9 mm. Hg. Right ventricular and pulmonary artery pressures were 40/11 and 40/16 mm. Hg, respectively. P u l m o n a r y capillary wedge pressure was also elevated a n d showed "a" and "v" waves of 16 and 21 mm. Hg. T h e r e was a positive hydrogen curve in the pulmonary artery. Pulmonary-tosystemic blood flow ratio was 1.3 and a left-to-right s h u n t of 0.64 L./min./M. ~ Left ventricular end-diastolic pressure was elevated at 22 mm. Hg. Left ventricular angiography showed 2 to 3 + mitral regurgitation, akinesis of a large portion of inferior wall, and a discreet inferior wall aneurysm just beneath the posterior medial papillary muscle. Right coronary artery (RCA) cineangiography revealed the RCA to be the dominant coronary artery with complete occlusion in its proximal portion. Both left anterior descending and left circumflex coronary arteries showed 50 per cent occlusion with poor distal vessels. The next day he developed Mobitz II heart block and a temporary transvenous pacemaker was inserted.
October, 1977, Vol. 94, No. 4
