INSUFFICIENCY OF THE HEART MUSCLE (MYASTHENIA CORDIS) Those functional disturbances of the child's heart should be in cluded here which depend upon permanent organic injury' to the power of the heart, whether there is question of primary organic injury to the heart muscle or of nayopathic results of mechanical obstruction t.o heart action (cardiac lesion, affection of the pericardium). Doubtless, as a result of the favorable relations of the heart muscle of children, the functional disturbances belonging here are rarer than in later life. Affections of the kidneys and lungs, the chief causes of myasthenia cordis in adults, come into question in childhood relatively I:ttle, pre cisely on this account. Whooping-cough alone, exceptionally, when it runs an especially severe course, leads to acute insufficiency of the heart, combined with dilatation (Silberma.nn, Hauser, d'Espine and Picot).
The chronic valvular lesions of the heart possess a high compensa tory tendency in childhood while, on the contrary, pericarditis and pericardial adhesion in children form the chief causes of this condition (Cadet de Gass:court, Malian, Weill). The pathogenesis of cardiac in sufficiency in children is therefore dependent essentially upon toxic myoearditis and mechanical obstruction to heart action by cardiac lesions and symphysis pericardii, which are associated with sclerosis of the niyocardium and parenchymatous myocarditis in many cases. The growth of fat about the heart, corollary sclerosis, the effects of alcohol and tobacco do not enter into the question.
symptoms of insufficiency of the heart muscle (asystolia of the French) are not. so outspoken in childhood as in older individuals. Considerable dilatation of the right side of the heart and functional tricuspid insufficiency' are only noted in a small number of chddren with heart disease. Auasarca also is commonly absent or as a rule first appears late in the disease, some weeks or days before death. Pulmonary catarrh from congestion and diminished secretion of urine occur more frequently and earlier than anasarca, but are less prominent on account of the decided symptonis of congestion in the liver which developed nitich earlier. In childhood the congestion of heart disease
affects the liver much more than the other organs, although it is diffi cult to understand why (Fig. 119). The liver is the single organ of the child in which symptoms of cardiac congestion are plainly observed, in the majority of ca.ses.
While myasthenia cordis does not affect the child's pulse in any characteristic manner, as it does in adult's (arrhythmia, gallop-rhythm), the symptoms in the respiratory organs are more severe. Often a dis proportion exists between the violent dyspncea and the very slight changes in the heart as shown by,- physical signs. The external habitus of children suffering from advanced myasthenia cordis, after it has lasted some time, hardly differs from that of the adult, except that dropsy is usually absent in children. Cyanosis of the peripheral parts of the body', venous stasis when the condition has lasted a long time and clubbed fingers are prominent symptoms.
Briefly then, in the majority of cases, there are symptoms of mod erate venous stasis, with marked disturbance of the hepatic circulation and only exceptionally symptoms of tricuspid insufficiency, with ana sarca, but always clecided dyspncea (over 40 respirations to the minute).
Prognosis and Course. While insufficiency of the heart muscle, under suitable treatment, may be well borne for years in adults, since it is possible within certain limits again and again to restore the insuffi cient cardiac muscle for a while, myasthenia coatis in childhood leads to death relatively rapidly, even if the cardiac insufficiency' occurring during the infectious diseases is considered completely apart from the acute conditions. The opinion as expressed by Weill that compensated heart affections in children are more benign than those of adults, al though those with loss of compensation are much more serious in the former than in the latter, is correct.