Oesophageal Electrocardiograms in Auricular Fibrillation.

A critical study of electrical events occurring in the posterior portions of the human heart has been made possible by the use of aesophageal leads in clinical electrocardiography (Cremer, 1906; Lieberson and Liberson, 1934; Luisada, 1935; Brown, 1936a, 1936b; Hamilton and Nyboer, 1938; Spiihler, 1938; Nyboer, 1939; Deglaude and Laubry, 1939). The cesophagus lies close to the posterior surface of the left auricle, being separated from it by a space, 0-5-1 cm. wide, composed of areolar tissue and by the two layers of the pericadium The right auricle lies 4-6 cm. anteriorly, across the cavity of the left; but beneath the most inferior part of the left auricle the cesophagus is separated from the inferior vena cava and the right auricle by a distance of only 1-2 cm. Brown (1936a) showed that an electrode lying in this part of the esophagus provided a nearly direct lead for the surface of the left auricle and, when paired with a distant electrode, was capable of recording faithfully the electrical changes of this region. From his study of 21 patients exhibiting auricular fibrillation Brown (1936b) concluded that, when it has become established and is not liable to spontaneous reversion to normal rhythm, the auricular deflections recorded by the cesophageal lead are of small amplitude and irregular form and do not exhibit intrinsic deflections, although the electrode lies against or close to the posterior (left auricular) segment of the pathway round which a circulating mother impulse is supposed to travel. Deglaude and Laubry (1939) also failed to record intrinsic deflections. Brown, however, did obtain records showing intrinsic deflections from two patients in whom fibrillation was associated with thyrotoxicosis; in one of these normal rhythm appeared after thyroidectomy. He suggested that, when auricular intrinsic deflections are recordable by the cesophageal lead, fibrillation may not be firmly established and may be susceptible to spontaneous reversion. We decided therefore to examine by means of the cesophageal lead cases of auricular fibrillation in which the arrhythmia was known to be paroxysmal or