These tachycardias predominate in the 

 female sex and there are a large number of 

 patients in which the number of heart beats 

 remains permanently between 100 and 200 

 or more per minute with regularity in the 

 succession of the cycles or with the presence 

 of extrasystoles. In these cases simultan- 

 eously with the acceleration of the heart 

 beats there occur other symptoms which in- 

 dicate the pathologic processes of the disease. 



Furthermore, two large systems pertain- 

 ing to the vegetative life, the thyroid and 

 the genital, which play important parts in 

 the physiologic equilibrium of the organism, 

 show appreciable anomalies which are man- 

 ifested by constant or very frequent syn- 

 dromes in the patients of this group. The 

 thyroid is almost always hypertrophied and 

 the generative functions show marked chang- 

 es which are expressed by intense dysmen- 

 orrhea with predominance of metrorrhagias. 

 However, symptoms of hyperfunction of 

 the ovaries constitute the principal genital 

 syndrome, in which the considerable increase 

 of the catamenias and the appearance of 

 supernumerary menstrual periods character- 

 ize the functional derangement of the 

 ovaries. 



As regards the thyroid the facts are 

 more complicated and the majority of the 

 patients represent types of dysthyroidism 

 with almost constant predominance of gland- 

 ular hypofunction, but with isolated feat- 

 ures of hyperthyroidism. 



From this anomaly theie must result 

 physiopathologic consequences which are 

 associated with either the function of one 

 of the systems or with the disturbance of 

 equilibrium in their interaction. Does the 

 tachycardia observed constitute a part of 

 such consequences? Aud does it indicate a 

 hyperthyroidism? We must report that in 

 men tachycardia is rarely observed although 

 the anatomic alterations of the thyroid are 

 of extreme frequency, and this indicates 

 with all certainty the influence of the fe- 

 male genital apparatus in its mechanism. If 

 the hypothesis of an endocrine influence on 



the chronotropic function of the heart mus- 

 cle be admitted, and its importance even 

 exaggerated, it would still remain to deter- 

 mine the exact process by which that influ- 

 ence is exercised in the cases we are dis- 

 cussing. Is there an increase in the tonus of 

 the sympathetic attributable to the function- 

 al disturbance of the thyroid, and in con- 

 sequence the acceleration of rhythm ? But 

 we must observe that in the cases of this 

 kind, at least in the majority of them, there 

 is found ovarian hyperfunction, manifested 

 by its classical symptoms. Now, in accord- 

 ance with the modern doctrines the ovar- 

 ian hormone exerts a depressive action on 

 the sympathetic, and this fact may contra- 

 dict the interpretation just formulated. 

 However, in spite of this, in the tachycard- 

 ias observed we are enabled to exclude 

 extracardiac interferences of a nervous nat- 

 ure associated with the endocrine process- 

 es. In the first place the sinus region can 

 be attacked by the pathologic changes involv- 

 ing all the myocardium, and from this 

 would result a greater excitability of the 

 node of Keith and Flack. This by itself is 

 capable of either causing the increase of 

 the contractile stimulus (and in this case the 

 tachycardia would be of intramuscular ori- 

 gin) or of modifying too much the normal 

 influence of the sympathetic, in this way 

 occasioning the acceleration of the heart 

 beats. Furthermore, and in the second place 

 the possible interference of the suprarenal 

 in these chronotropic changes must be ad- 

 mitted, since this is a frequent site of local- 

 izations of the parasite and of histologic 

 changes, and its functional disturbance may 

 act upon the cardiac rhythm. 



And even this is not all of the difficult- 

 ies in the interpretation that we are seeking, 

 since those arrhythmias maybe independent 

 of extracardiac nervous factors and may in- 

 dicate only the weakness of the muscle, thus 

 representing the functional manifestation of 

 the pathologic processes found there. 



The complexity of the subject is evi- 

 dent and only protracted investigations can 



