LETTERS TO THE EDITOR Letters to the Editor will be published, if suitable, and as space permits. They should not exceed 1,000 words (typed double spaced) in length, and may be subject to editing or abridgment.
ECG Classification of WPW Affects Echo Assessment
syndrome. Analysis based upon localization of the accessory pathway by epicardial mapping. Circulation 52: 1030, 1975 5. Durrer D, van Dam RT, Freud GE, Janse MJ, Meijler FL, Arzbaecher RC: Total excitation of the isolated human heart. Circulation 41: 899, 1970
To the Editor: We read with interest the article by Chandra et al.' reporting echocardiographic studies in patients with the WPW syndrome. We believe that it is important in communications of this type that uniformity exist in classification of patients with pre-excitation as to anatomical site of earliest ventricular activation. Most workers use a classification based upon that of Boineau et al., as do Chandra and co-workers.2' However, Chandra et al. appear to misinterpret Boineau's classification, by utilizing the 30 msec vector in the horizontal plane (which is not described by Boineau et al.) and by ignoring the frontal plane vector of the delta wave. Boineau's classification employs the initial QRS (delta) vector as reflected in both the frontal and horizontal planes of the scalar electrocardiogram. In principle, a superior initial vector (negative in III, aVF) implies pre-excitation of the diaphragmatic surface; an inferior initial vector (positive in I1I, aVF) implies pre-excitation of the parietal free walls of the ventricles. The laterality of pre-excitation is determined by the QRS vector in V,. Scrutiny of the authors' illustrative electrocardiograms reveal some discrepancies with the above described criteria. In figure 1, the first electrocardiogram, shown as an illustration of anterior right ventricular pre-excitation, has a superior initial vector. Most workers would interpret this pattern as reflecting posterior right ventricular pre-excitation. The second electrocardiogram, shown as an example of posterior right ventricular pre-excitation, has a positive delta wave in V1 and is more typical of posterior left-sided pre-excitation. The third electrocardiogram, shown as an example of posterior left ventricular pre-excitation, has an inferior initial vector and a negative delta wave in aVL and would be interpreted by most as more typical of lateral rather than posterior left ventricular pre-excitation. We would also observe that reliance on the partially pre-excited electrocardiogram (as in sinus rhythm) for criteria with which to predict the anatomic location of accessory atrioventricular muscle bundles is hazardous. Delta forces in the fully pre-excitated electrocardiogram have been shown to be more reliable.' It should also be noted that the authors incorrectly interpret normal ventricular activation, which begins not in the "upper part" of the interventricular septum, but rather in the middle and apical thirds of the left septum.6 Since many of the authors' patients may be erroneously classified as to site of pre-excitation, the conclusions regarding echocardiographic patterns associated with specific sites of pre-excitation have to be accepted with reservations. C.R. WYNDHAM, M.B. P. DENES, M.D. K. M. ROSEN, M.D. University of Illinois Chicago, Illinois
The authors reply: To the Editor: Currently available electrophysiologic studies have emphasized that the spatial direction of the initial forces in Wolff-ParkinsonWhite patients is quite variable. Epicardial mapping studies in patients operated on with pre-excitation suggest that accessory pathways can be present anywhere on either anulus as well as the interatrial septum and the region of the central fibrous body.' Thus, difficulty will be encountered in any attempt to relate the ECG to a unique anatomic site.' We used the general concepts of Boineau et al.2 but emphasized leads V,, V2 and V6 and the 30 msec Frank vector, as detailed in our paper. This was done in order to classify our patients using simple techniques and concepts which would be readily available to most clinicians; in this regard we have followed the approach and classification of Castellanos et al.3 Our echocardiographic observations should therefore be related to patients classified as we specifically outlined, and may not necessarily apply if additional superior-inferior initial vector criteria were used, as proposed by Wyndham et al. We did not mean to imply otherwise. We agree that the fully pre-excited electrocardiogram, as achieved by right or left atrial pacing, is a more reliable predictor of the site of accessory pathways.' The majority of our patients had no cardiac symptoms or had symptoms unrelated to their WPW, and such invasive electrophysiologic studies did not appear justified. Conclusions drawn from a relatively small group of patients should always be accepted with caution. However, since submission of our manuscript two other studies of echocardiography in WPW have appeared;4' one' utilized pacing techniques. Both of these investigations arrived at conclusions similar to ours - that abnormalities of interventricular septal motion occur in Type I (anterior right ventricle) pre-excitation but not Types II and III. Ticzon et al.' also emphasized the importance of the anteroposterior delta vector orientation; septal motion was always normal when the delta vector was directed anteriorly and abnormal when it was posteriorly directed (Type I). Information on the orientation of the anteroposterior delta vector is readily obtainable from leads V, and V2 and the horizontal plane Frank vector, as we used them. MICHAEL S. CHANDRA, M.D. RICHARD E. KERBER, M.D. DONALD D. BROWN, M.D. DAVID C. FUNK, M.D. The University of Iowa Iowa City, Iowa
References 1. Gallagher JJ, Gilbert M, Svenson RH: Wolff-Parkinson-White syndrome. The problem, evaluation and surgical correction. Circulation 51: 767, 1975 2. Boineau JP, Moore EN, Spear JF, Sealy WC: Basis of static and dynamic electrocardiographic variations in Wolff-Parkinson-White syndrome. Am J Cardiol 32: 32, 1973 3. Castellanos A, Lemberg L, Claxton BW: Wolff-Parkinson-White syndrome: generalities. Chest 65: 307, 1974 4. Ticzon AR, Damato AN, Caracta AR, Russo G, Foster JR, Lau SH: Interventricular septal motion during pre-excitation and normal conduction in Wolff-Parkinson-White syndrome. Am J Cardiol 37: 840, 1976 5. Francis GS, Theroux P, O'Rourke RA, Hagan AD, Johnson AD: An echocardiographic study of interventricular septal motion in the WolffParkinson-White syndrome. Circulation 54: 174, 1976
References 1. Chandra MS, Kerber RE, Brown DD, Funk DC: Echocardiography in Wolff-Parkinson-White syndrome. Circulation 53: 943, 1976 2. Boineau JP, Moore EN, Spear JF, Sealy WC: Basis of static and dynamic electrocardiographic variations in Wolff-Parkinson-White syndrome. Am J Cardiol 32: 32, 1973 3. Gallagher JJ, Gilbert M, Svenson RH, Sealy WC, Kasell J, Wallace AG: Wolff-Parkinson-White syndrome: the problem, evaluation and surgical treatment. Circulation 51: 767, 1975 4. Tonkin AM, Wagner GS, Gallagher JJ, Cope GD, Kasell J, Wallace AG: Initial forces of ventricular depolarization in the Wolff-Parkinson-White
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ECG classification of WPW affects echo assessment. C R Wyndham, P Denes and K M Rosen Circulation. 1977;55:823 doi: 10.1161/01.CIR.55.5.823 Circulation is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231 Copyright © 1977 American Heart Association, Inc. All rights reserved. Print ISSN: 0009-7322. Online ISSN: 1524-4539
The online version of this article, along with updated information and services, is located on the World Wide Web at: http://circ.ahajournals.org/content/55/5/823.citation
Permissions: Requests for permissions to reproduce figures, tables, or portions of articles originally published in Circulation can be obtained via RightsLink, a service of the Copyright Clearance Center, not the Editorial Office. Once the online version of the published article for which permission is being requested is located, click Request Permissions in the middle column of the Web page under Services. Further information about this process is available in the Permissions and Rights Question and Answer document. Reprints: Information about reprints can be found online at: http://www.lww.com/reprints Subscriptions: Information about subscribing to Circulation is online at: http://circ.ahajournals.org//subscriptions/
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ECG Classification of WPW Affects Echo Assessment
syndrome. Analysis based upon localization of the accessory pathway by epicardial mapping. Circulation 52: 1030, 1975 5. Durrer D, van Dam RT, Freud GE, Janse MJ, Meijler FL, Arzbaecher RC: Total excitation of the isolated human heart. Circulation 41: 899, 1970
To the Editor: We read with interest the article by Chandra et al.' reporting echocardiographic studies in patients with the WPW syndrome. We believe that it is important in communications of this type that uniformity exist in classification of patients with pre-excitation as to anatomical site of earliest ventricular activation. Most workers use a classification based upon that of Boineau et al., as do Chandra and co-workers.2' However, Chandra et al. appear to misinterpret Boineau's classification, by utilizing the 30 msec vector in the horizontal plane (which is not described by Boineau et al.) and by ignoring the frontal plane vector of the delta wave. Boineau's classification employs the initial QRS (delta) vector as reflected in both the frontal and horizontal planes of the scalar electrocardiogram. In principle, a superior initial vector (negative in III, aVF) implies pre-excitation of the diaphragmatic surface; an inferior initial vector (positive in I1I, aVF) implies pre-excitation of the parietal free walls of the ventricles. The laterality of pre-excitation is determined by the QRS vector in V,. Scrutiny of the authors' illustrative electrocardiograms reveal some discrepancies with the above described criteria. In figure 1, the first electrocardiogram, shown as an illustration of anterior right ventricular pre-excitation, has a superior initial vector. Most workers would interpret this pattern as reflecting posterior right ventricular pre-excitation. The second electrocardiogram, shown as an example of posterior right ventricular pre-excitation, has a positive delta wave in V1 and is more typical of posterior left-sided pre-excitation. The third electrocardiogram, shown as an example of posterior left ventricular pre-excitation, has an inferior initial vector and a negative delta wave in aVL and would be interpreted by most as more typical of lateral rather than posterior left ventricular pre-excitation. We would also observe that reliance on the partially pre-excited electrocardiogram (as in sinus rhythm) for criteria with which to predict the anatomic location of accessory atrioventricular muscle bundles is hazardous. Delta forces in the fully pre-excitated electrocardiogram have been shown to be more reliable.' It should also be noted that the authors incorrectly interpret normal ventricular activation, which begins not in the "upper part" of the interventricular septum, but rather in the middle and apical thirds of the left septum.6 Since many of the authors' patients may be erroneously classified as to site of pre-excitation, the conclusions regarding echocardiographic patterns associated with specific sites of pre-excitation have to be accepted with reservations. C.R. WYNDHAM, M.B. P. DENES, M.D. K. M. ROSEN, M.D. University of Illinois Chicago, Illinois
The authors reply: To the Editor: Currently available electrophysiologic studies have emphasized that the spatial direction of the initial forces in Wolff-ParkinsonWhite patients is quite variable. Epicardial mapping studies in patients operated on with pre-excitation suggest that accessory pathways can be present anywhere on either anulus as well as the interatrial septum and the region of the central fibrous body.' Thus, difficulty will be encountered in any attempt to relate the ECG to a unique anatomic site.' We used the general concepts of Boineau et al.2 but emphasized leads V,, V2 and V6 and the 30 msec Frank vector, as detailed in our paper. This was done in order to classify our patients using simple techniques and concepts which would be readily available to most clinicians; in this regard we have followed the approach and classification of Castellanos et al.3 Our echocardiographic observations should therefore be related to patients classified as we specifically outlined, and may not necessarily apply if additional superior-inferior initial vector criteria were used, as proposed by Wyndham et al. We did not mean to imply otherwise. We agree that the fully pre-excited electrocardiogram, as achieved by right or left atrial pacing, is a more reliable predictor of the site of accessory pathways.' The majority of our patients had no cardiac symptoms or had symptoms unrelated to their WPW, and such invasive electrophysiologic studies did not appear justified. Conclusions drawn from a relatively small group of patients should always be accepted with caution. However, since submission of our manuscript two other studies of echocardiography in WPW have appeared;4' one' utilized pacing techniques. Both of these investigations arrived at conclusions similar to ours - that abnormalities of interventricular septal motion occur in Type I (anterior right ventricle) pre-excitation but not Types II and III. Ticzon et al.' also emphasized the importance of the anteroposterior delta vector orientation; septal motion was always normal when the delta vector was directed anteriorly and abnormal when it was posteriorly directed (Type I). Information on the orientation of the anteroposterior delta vector is readily obtainable from leads V, and V2 and the horizontal plane Frank vector, as we used them. MICHAEL S. CHANDRA, M.D. RICHARD E. KERBER, M.D. DONALD D. BROWN, M.D. DAVID C. FUNK, M.D. The University of Iowa Iowa City, Iowa
References 1. Gallagher JJ, Gilbert M, Svenson RH: Wolff-Parkinson-White syndrome. The problem, evaluation and surgical correction. Circulation 51: 767, 1975 2. Boineau JP, Moore EN, Spear JF, Sealy WC: Basis of static and dynamic electrocardiographic variations in Wolff-Parkinson-White syndrome. Am J Cardiol 32: 32, 1973 3. Castellanos A, Lemberg L, Claxton BW: Wolff-Parkinson-White syndrome: generalities. Chest 65: 307, 1974 4. Ticzon AR, Damato AN, Caracta AR, Russo G, Foster JR, Lau SH: Interventricular septal motion during pre-excitation and normal conduction in Wolff-Parkinson-White syndrome. Am J Cardiol 37: 840, 1976 5. Francis GS, Theroux P, O'Rourke RA, Hagan AD, Johnson AD: An echocardiographic study of interventricular septal motion in the WolffParkinson-White syndrome. Circulation 54: 174, 1976
References 1. Chandra MS, Kerber RE, Brown DD, Funk DC: Echocardiography in Wolff-Parkinson-White syndrome. Circulation 53: 943, 1976 2. Boineau JP, Moore EN, Spear JF, Sealy WC: Basis of static and dynamic electrocardiographic variations in Wolff-Parkinson-White syndrome. Am J Cardiol 32: 32, 1973 3. Gallagher JJ, Gilbert M, Svenson RH, Sealy WC, Kasell J, Wallace AG: Wolff-Parkinson-White syndrome: the problem, evaluation and surgical treatment. Circulation 51: 767, 1975 4. Tonkin AM, Wagner GS, Gallagher JJ, Cope GD, Kasell J, Wallace AG: Initial forces of ventricular depolarization in the Wolff-Parkinson-White
823 Downloaded from http://circ.ahajournals.org/ by guest on March 25, 2015
ECG classification of WPW affects echo assessment. C R Wyndham, P Denes and K M Rosen Circulation. 1977;55:823 doi: 10.1161/01.CIR.55.5.823 Circulation is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231 Copyright © 1977 American Heart Association, Inc. All rights reserved. Print ISSN: 0009-7322. Online ISSN: 1524-4539
The online version of this article, along with updated information and services, is located on the World Wide Web at: http://circ.ahajournals.org/content/55/5/823.citation
Permissions: Requests for permissions to reproduce figures, tables, or portions of articles originally published in Circulation can be obtained via RightsLink, a service of the Copyright Clearance Center, not the Editorial Office. Once the online version of the published article for which permission is being requested is located, click Request Permissions in the middle column of the Web page under Services. Further information about this process is available in the Permissions and Rights Question and Answer document. Reprints: Information about reprints can be found online at: http://www.lww.com/reprints Subscriptions: Information about subscribing to Circulation is online at: http://circ.ahajournals.org//subscriptions/
Downloaded from http://circ.ahajournals.org/ by guest on March 25, 2015
