296 Mayow 



cartilage adhering to its interior, so that blood could 

 scarcely enter the ventricle. Indeed, there can be no 

 doubt that the obstruction of the pulmonary vein 

 was the cause not only of the palpitation from which 

 the patient suffered, but also of the above-mentioned 

 phenomena. For as the blood could not, on account 

 of the obstruction, pass into the left ventricle of the 

 heart, the pulmonary blood-vessels and also the right 

 ventricle were necessarily distended with blood. So^ 

 too, the heart, and especially that ventricle, was 

 forced to contract violently so as to propel the mass 

 of the blood as much as possible through the lungs 

 into the left ventricle of the heart. And this also 

 accounts for the great thickness and strength of the 

 right ventricle, since muscles accustomed to more 

 violent exercise increase more than others. But that 

 the heart should have been dashed against the left 

 side of the chest with such violence that its ribs were 

 bent outwards, although it was the right ventricle of 

 the heart only that was swollen like a tumour, is to 

 be explained by what has been said above ; for, indeed, 

 as the blood could not be all expelled from the right 

 ventricle because of the aforesaid obstruction, it, 

 compressed by the violent contraction of the muscular 

 wall of that ventricle, drove the septum of the heart 

 and so also the heart itself to the left side, as we have 

 shown above. 



It is also to be noted that palpitation of the heart, 

 such, namely, as occurs suddenly and unexpectedly, 

 may come from this, that the blood, strongly 

 fermenting and set in violent motion, rushes too 

 quickly into the ventricles of the heart ; so that the 

 heart must needs contract with more than its usual 

 force to expel the greater quantity of blood. For it 

 must not be forgotten that the heart, like other 



