Ventricular Preexcitation: Historical Overview

The Earliest Published Electrocardiogram Showing Ventricular Preexcitation

“…In contrast to the 1909 case, they show orthodromic AV reentry during their tachycardias. Neither case is mentioned in historical treatises on the WPW syndrome 9,10,13,14 . Though they were not published until 1914, their ECGs represent recordings of the very first patients with preexcitation who were investigated by electrocardiography, the only method able to disclose it (cf.…”

“…In 1930, Wolff, Parkinson, and White published their article “Bundle‐branch block with short P‐R interval in healthy young people prone to paroxysmal tachycardia.” 1 In addition to their own 11 patients, the authors found four comparable cases in the literature, 2–5 one 4 being their case IX 1 . Later on, a few further examples published prior to 1930 6–8 were discovered 9,10 . The earliest 9 of them was that of Cohn and Fraser in 1913 6…”

Response to the Editor:

“…In regard to Professor Anderson's concern that we may have overstated the value of Kent's contributions in regard to free‐wall atrioventricular connections, 4,5 we point out that our comments were restricted to the potential role of such connections in anomalous conduction 1 . We fully subscribe to the point made by Anderson et al in 1996 3 that “Kent was mistaken in his belief that there were multiple pathways for atrioventricular conduction in the normal heart.” 3 Furthermore, we did not intend in our Editorial to downplay Mahaim's and Burchell’s 6–8 criticism of Kent's assertion that he had demonstrated anomalous conduction capability over a right‐sided node (“while Kent did report demonstrating anomalous conduction over a node‐like right free‐wall AV connection [despite criticism to the contrary by Mahaim and later by Burchell], he did not describe an “insulated” connection”). Further, we noted in the legend of Figure 2 that “Mahaim depicts the controversial fibers along the right free‐wall described by Kent.” Our thought process at the time was focused on finding the evidence of “insulated” tracts, and it seems evident that neither Kent nor Mahaim observed such things.…”

Re: Atriofascicular Tracts

“…Both Benditt and Lu and Burchell reproduce the figure drawn by Mahaim to show the incision made by Kent in an attempt to substantiate his opinion. As Burchell commented in his historical review, however, “This assertion strains one's credulity.” 6 Indeed it does. Furthermore, although Burchell also reproduced one of Kent's illustrations as given to the Physiological Society, careful review of all his illustrations shows that Kent never demonstrated muscular connections crossing the atrioventricular junctions.…”

“…As Benditt and Lu also explain, subsequent electrophysiological experience showed that, rather than being dependent on Mahaim's paraspecific fibers, the conduction described in his name was far more likely to occur across a special type of accessory muscular atrioventricular connection. Benditt and Lu then refer the reader to the excellent review of the historical aspects given by Benditt's mentor, and my old friend, Howard Burchell 6 . There is no doubt about the excellence of Howard's account, but I would be so bold to suggest that, in his account, he was more than generous to the descriptions given around the turn of the century by Stanley Kent for the existence of multiple pathways of conduction across the plane of atrioventricular insulation in the normal heart.…”