D

URING recent years the dis

orders of the cardiac mechanism have been the subject of renewed attention, and have acquired new significance. This has resulted, on the one hand, from studies such as those of Lewis and of DeBoer which have dealt with their fundamental nature, and, on the other hand, studies as those of Eyster and of Carter concerning inherent effect of disordered mechanisms on the myocardium and the general mass movement of blood. Auricular flutter, though not a common disturbance of the mechanism is well known where routine electrocardiographic examinations are made. It was first described by MacWilliam in 1887 as a rapid and regular rhythm originating in the mammalian auricle following faradic stimulation. The term was first applied clinically by Jolly and Ritchie in 1911. Three years later appeared the monograph of Ritchie (1) based on the study of 53 cases. Since that time there have been numerous clinical papers on the subject, reporting a small number of cases or emphasizing some particular phase of the question. In 1918 Blackford and Willius (2) described 16 cases, and in 1922 Keating and Hajek (3) reported 8 cases and interpreted certain findings in the light of the

From the Rowe Memorial Cardiographic

Laboratory, Mercy Hospital, Pittsburgh,

Pa.

ANNALS OF CLINICAL MEDICINE, VOL. III, NO. 1

circus movement. No attempt will be made here to review the literature. The present study includes 16 cases of pure flutter; observations on the action of certain drugs have already been published (4); the case numbers given here correspond with those in the preceding paper.

CLINICAL NOTES

The incidence of flutter is difficult to estimate; in 1200 electrocardiographic examinations made at this hospital there have been 9 cases of flutter, 137 of fibrillation and 15 of paroxysmal tachycardia. Flutter is doubtless more common in clinics whose cases represent a greater percentage of advanced heart disease than is seen in this one. The disorder predominates in males, and, as has been frequently pointed out, is more common in the latter decades of life (table 1). These cases add but little concerning the possible duration. of flutter; in Case 9 the disorder had probably been continuous for one year; that which resulted from digitalis (case 4) lasted for thirty hours; in cases 8 and 14 the flutter was transient. Of greater interest is the tendency in certain hearts for flutter to reëstablish itself at approximately the original rate, thus dominating the normal rhythm or fibrillation that had resulted from treatment (cases 1 and 3, table 2 and case histories).

and 160. The production of irregular ventricular block by vagal pressure in the neck will differentiate it from paroxysmal tachycardia, in which the vagus will either produce no effect or abruptly terminate the abnormal rhythm (fig. 1). But this procedure is often without influence in flutter and

rhythm seen at rest, and a phase with regular tachycardia produced by exercise or excitement, e.g., cases 3, 6, 8, 9 and 13. Such variation in ventricular rhythm can occur only in flutter. In cases 11 and 12 and 16, vagal pressure and exercise were without appreciable effect. Roentgenoscopy, first

pointed out by Holmes and White (5), may offer a safe guide in certain cases; in cases 9, 11, 13 and 17 of this series the mechanism was quite apparent at the fluoroscopic examination; in case 16 no definite sequence of auricular systoles could be followed. Wiggers (6) has shown that in pure flutter a true muscular contraction of the auricles follows each excitation wave; visible recognition of auricular activity apparently depends on the strength of auricular beating in a given case and is not dependent on the rate alone (contrast cases 11 and 13 and 16).

The symptoms that could be related to the presence of flutter were those of cardiac failure and tachycardia, namely, dyspnea and palpitation. In 2 cases (1 and 14) there were no symptoms referable to the circulatory system and flutter was discovered when electrocardiograms were taken because of irregularity of the pulse. Sudden attacks of dyspnea and palpitation with tachycardia, the importance of which has been emphasized by Ritchie for the recognition of flutter, occurred 3 times (cases 6, 9 and 13). In case 17, palpitation became severe on exertion and was doubtless related to the bigh rate of ventricular beating, a ventricular rate of approximately 260 was recorded following exercise (fig. 3). However, from the disappearance of palpitation with the restoration of normal mechanism in certain of these cases and in a larger group in which fibrillation has been converted to normal rhythm it now seems certain that palpitation may result from increased auricular activity, for it has persisted in spite of slowing of ventricular rate, to disappear with the return of normal auricular beating (see also case 7).

In considering the associated pathology, it is at once apparent that flutter may occur in any type of cardiac lesion; it is also said to occur in apparently normal hearts. The underlying pathology of the disorders of mechanism is now known to be chemical rather than anatomical, but the rarity of flutter in chronic valvular disease, especially rheumatic mitral disease in which fibrillation is so common, is striking. Of 2 cases of mitral stenosis in the series the flutter was produced by digitalis in 1 (fig. 4) and that drug was probably responsible for its presence in the other (case 15). In 4 cases there was high grade pulmonary emphysema and in 1, pulmonary tuberculosis. Proved syphilis occurred 3 times. Of the cases in which X-ray examinations were made there was but 1 which showed no enlargement of the heart (case 14), and this examination was not made at the time that flutter was present. In the remainder, although the heart as a whole was not always greatly enlarged and the transverse diameters were not above possible normal values, definite exaggeration of the curves of one or both auricles was found.

It has not been possible to study adequately the effect of flutter on the circulation in these cases. In 5 cases there were no signs of myocardial insufficiency when flutter was first recorded. Blood pressure has been maintained at levels approximately normal for the individual (table 2); in case 6 the pressure was governed by the ventricular rate, but this did not hold in case 9. In cases 12 and 13 the systolic level. was higher after the onset of normal rhythm; in cases 11 and 16, it was lower. In 3 cases, the size of the