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Scientific Proceedings (125) 



dividuals, by small changes in the position of the triangle of 

 leads, resulting in a change of the anatomical angle of the heart 

 of 40° or less, we obtained curves which actually resembled 

 curves found in disease and resembled closely those often thought 

 to be abnormal found in the young soldiers and civilians already 

 mentioned. These were curves like those seen when the left side 

 of the heart is large ; in other positions, though anatomically quite 

 improbable, we obtained curves resembling enlargement of the 

 right side of the heart. 



In patients whose hearts were known to be diseased and whose 

 curves were characteristic of these conditions we applied the same 

 technique. We found that at some position in the course of 

 rotating the leads, curves were obtained which approached the 

 appearance of normal. 



That curves of approximately normal appearance can be ob- 

 tained is of theoretical interest. But that in obviously normal 

 persons, yielding abnormal curves, normal curves can be ob- 

 tained by a slight alteration of the position of the heart in the 

 chest is a matter of genuine practical importance. It does not 

 simplify the interpretation of electrocardiograms, but for the 

 moment it does something quite as important; it shows how the 

 normal individual may be saved from being considered the sub- 

 ject of chronic heart disease because of an abnormality in his 

 curve. This danger is not theoretical. 



We have not by these experiments solved the problem of the 

 relation of hypertrophy of the heart to patent abnormality in 

 the electrocardiogram, but we have shown systematically and 

 clearly that, especially in doubtful cases, the position of the nor- 

 mal heart in the chest must be taken into account as a factor in 

 the production of abnormal curves as well as the position of the 

 abnormal heart in the chest in the production of normal ones. 



