Digitalis in Heart Failure with Normal Rhythm.

In the first edition of his Diseases of the Heart, published in 1908, Mackenzie said: " the nodal rhythm is present in the majority of cases of severe heart failure and in a great many the immediate breakdown is directly attributable to the inception by the heart of this abnormal rhythm." In the third edition, in 1913, the term " auricular fibrillation " was substituted for that of " nodal rhythm," the researches of Lewis and others having established their identity. Mackenzie gave the proportion as " 60 or 70 per cent. of all cases of serious heart failure met with in practice." It is even now generally admitted that auricular fibrillation affects the majority. Lewis (1937) has said that at least 70 per cent. of all cases of failure with congestion display fibrillation. To quote Mackenzie (1911) on digitalis: " Cases of auricular fibrillation are more readily and more markedly affected than cases with normal rhythm." Dissentient views began to be expressed perhaps first by Janeway (1913), and later especially by Christian (1919) whose paper was entitled " Digitalis therapy: satisfactory effects in cardiac cases with regular rhythm." In a further study (Christian, 1922) he affirmed that: " Digitalis is fully as effective in the treatment of chronic cardiac cases without auricular fibrillation as it is in those with fibrillation." Luten (1924) reached the same conclusion. Yet most authors to-day admit that the beneficial effect is greater in auricular fibrillation, though they do not deny (and Mackenzie did not) that it is also effective in heart failure without fibrillation. Lewis's experience is that occasional cases presenting regular heart action respond favourably (Lewis, 1937). We have spoken as if auricular fibrillation occurred indiscriminately in heart failure and as if the response to digitalis depended simply on the presence or absence of this arrhythmia. But it might be that fibrillation connoted a different group of cardiac lesions and thereby a different reaction to digitalis. It was with this idea in mind that Parkinson and Clark-Kennedy (1926) undertook an inquiry into heart failure with normal rhythm. It was established that there is an important relation between the pathological basis for a cardiac disease and failure and the presence or absence of fibrillation. In general,