THYROID INSUFFICIENCY 73 



threatening haemorrhage, to work with big doses 

 or to try for a speedy result. In heart cases, 

 where there is cardiac pain and distinct dilatation, 

 the treatment should be commenced with a few 

 days of absolute rest in bed ; with this the response 

 will be much quicker, and one is able to form a 

 more accurate judgment as to what is permanent 

 and what is passing in the heart's attitude. In 

 all cases wise advice, as to rest and exercise, is 

 needed, and both, if well ordered, will help to 

 lower pressure, but we must always remember 

 that these hearts in people over 50 have not 

 much reserve, and come to their dynamic limit 

 rather suddenly. One is often surprised to find 

 a dilated heart and feeble pulse with high arterial 

 tension even of 200 mm. The work of Starling 

 throws light on this apparent paradox. He says : 

 " The contractile force of a muscle depends 

 upon and is proportionate to its previous stretch- 

 ing, so that in its inception even cardiac dilata- 

 tion is compensatory, and a rise of blood-pressure 

 will increase the stretching of the cardiac muscle. 

 But it is a desperate expedient, for with the over- 

 stretching complete failure may ensue." The 

 work of many of these high-pressure hearts is 

 like the work of Sisyphus, without help almost 

 hopeless ; we can help them slightly by increasing 



