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Localization of the Site of Myocardial Scarring in Man by High-Frequency Components By NANCY C. FLOWERS, M.D., LEO G. HORAN, M.D., W. J. TOLLESON, M.D., AND J. R. THOMAS, M.D. Downloaded from http://circ.ahajournals.org/ by guest on April 29, 2017 SUMMARY The increased incidence of high-frequency components (notching) in electrocardiographic (ECG) recordings previously has been related to coronary artery disease, primary myocardial disease, and biventricular enlargement. This study included 130 subjects on whom autopsy permission was obtained, who had one or more sets of high-frequency, orthogonal ECG (XYZ) leads and directwriting standard ECG leads recorded ante mortem. In each instance careful dissection of the heart was performed by two or more of the authors according to fixed protocol. Correlations were made between the site of infarction and the occurrence of notching in specific high-frequency ECG leads. Postero-inferior infarctions tended to express themselves with a predominance of increased notching in the Y lead, while anterior infarction manifested dominantly in the X lead. This was true in intramural as well as transmural lesions. The greatest value of notch recognition in diagnosing and localizing infarction appeared to be in subjects with normal sized hearts, with none of the classic ECG criteria for infarction, but who ultimately proved to have intramural scarring. In these subjects the increased incidence of notching clearly could not be attributed to biventricular enlargement, nor could the ECG diagnosis of infarction be arrived at by conventional criteria. Additional Indexing Words Intramural infarction QRS notching and slurring frequency notching of the QRS complex in the absence of conduction delay has been the subject of intermittent reports since Langner began his studies in 1952. This work ultimately led to a correlation between highfrequency notching and coronary artery disease.1-8 Burch's group9-1' and Selvester and From the Section of Cardiology, Medical Service, Forest Hills Veterans Administration Hospital; the Department of Medicine, Medical College of Georgia, Augusta, Georgia; the Section of Cardiology, Medical Service, Kennedy Veterans Administration Hospital; and the Division of Cardiovascular Diseases, Department of Medicine, University of Tennessee School of Medicine, Memphis, Tennessee. This study was supported by a research grant from the Tennessee Heart Association, Grants HE-5586, HE-08861, and HE-09495 of the National Institutes of Health, U. S. Public Health Service, and a research grant from the Georgia Heart Association. Address for reprints: Nancy C. Flowers, M. D., Chief, Section of Cardiology, FHD, Veterans Administration Hospital, Augusta, Georgia 30904. loop (VCG) and related these to overt myocardial infarction as well as to patchy scarring. In a well-controlled computer study, Pipberger and Carter13 attempted to establish the upper limit of normal for the numbers of high-frequency departures in the vectorcardiographic loop. More recently Reynolds and colleagues14 related high-frequency components to primary myocardial disease. Still more recently, we pointed out with detailed postmortem correlation, the fact that patients with biventricular enlargement also have an extremely high T HE CLINICAL importance of high- Circulation, Volume XL, December 1969 co-workers12 appreciated the significance of bites and notches in the vectorcardiographic 927 FLOWERS ET AL. 928 Downloaded from http://circ.ahajournals.org/ by guest on April 29, 2017 incidence of high-frequency components. In fact, patients with biventricular enlargement cannot be separated as a population group from patients with myocardial scarring on the basis of notch count. Furthermore, the groups of patients with either scarring or biventricular enlargement are clearly distinguishable from normal subjects (P<0.01) 15 With epicardial and plunge electrode recordings, Durrer and associates"' demonstrated alteration of conduction pathway around induced scars in the dog's ventricle. In 1966 Langner17 showed that intramural lesions created in nine experimental animals were expressed in six of them by high-frequency notching of the QRS complex. Our present study was undertaken to determine whether the particular orthogonal lead (XYZ) with maximal notching reliably pointed to the site of myocardial infarction. Especially were we concerned with whether the incidence of high-frequency components in specific leads indicated the presence and location of intramural myocardial scars otherwise not apparent. Finally, we studied the value of notching or slurring on the downstroke of the R wave in leads IL III, and aVF of the direct-writing ECG as a possible predictor of inferior myocardial infarction. Methods From 1963 through 1967, on 1,300 male patients admitted to the Kennedy Veterans Administration Hospital, vectorcardiographic loops and scalar leads XYZ of the McFee-axial lead system were obtained.'8 At the same sitting, high-frequency ECG leads I, VF, and V1 to V5 were recorded with a constant V4 control for all frames. Direct-writing standard ECGs were also obtained. The high-frequency recordings were obtained by photography from the face of a cathode-ray oscilloscope at sweep speeds of 500 and 200 mm/sec. A minimum of two such sets for each lead was obtained. Follow-up sets were obtained at the time of each subsequent admission. The same XYZ leads were recorded on 36 apparently healthy, male medical students and faculty. The frequency response of the highfrequency system was 0.2 to 10,000 cycles/sec (cps). To be included, a notch or slur would have to appear consistently in two or more QRS complexes at each sweep speed. By the technics described by Langner and associates,5 6, 19 notches and slurs in the QRS complex were counted in the high-frequency recordings. Notches will be defined as departures in both slope and sign from the primary QRS curve after the artifacts of noise have been excluded. These departures will be exclusive of the fundamental directional changes of the complex; in other words, the nadir of a Q or an S, or the peak of an R. Slurs will be defined as changes of slope without changes of sign. Unless indicated, slurs and notches will be counted together and referred to as "notches." The presence of slurring or notching in the latter half of the QRS complex of II, III, aVF or V5, and V6 were tabulated from the standard direct-writing ECG (upper frequency response about 70 cps). At the end of 4 years, 130 subjects had come to autopsy. In each case, two or more of the authors personally performed fresh dissections of each heart according to prospective protocol. The vascular tree was serially sectioned and again opened longitudinally from the ostia distally. The left ventricle and the interventricular septum were separated from the free wall of the right ventricle after complete removal of the fat. The perimeter of the right ventricle was traced and measured planimetrically to establish area, and the right ventricle was weighed separately. The left ventricular free wall and septum were weighed together. Both the free wall and septum were sliced longitudinally at 0.5-cm levels from apex to base to expose the intramural surfaces. The results of the dissections were recorded on protocol sheets with notations of the right ventricular area, right and left ventricular weights, lesions in the coronary arterial tree, and the exact size and site of myocardial lesions. These lesions were photographed in color. Because of advanced conduction defects, 13 subjects were eliminated from the study. The groups were divided after autopsy into subjects with predominantly anterior infarction, predominantly postero-inferior infarction, biventricular enlargement, left ventricular enlargement, right ventricular enlargement, spotty myocardial infarction, and a group of autopsied subjects with normal hearts, "old normals." The 36 medical students comprised a nonautopsied group of 'young normals." Comparisons of the relative frequency of notching in each lead within a given group of subjects were tested by Student's t-test while comparisons between groups were tested by Cochran's modification of the t-test.20 Results In table 1 the lead showing predominant notching in each group is indicated. In the Cficulation, Volume XL, December 1969 LOCALIZATION OF MYOCARDIAL SCARRING 929 Table 1 Predominance of Notching in Groups No. of subjects Anterior 24 Posterio-inferior 24 X Y Lead of predominant notching Z YZ XY Groups with infarction 9 5 5 37.5% 1 13 4 4 ZX XYZ 1 4 1 1 54.2% Downloaded from http://circ.ahajournals.org/ by guest on April 29, 2017 Spotty 17 BVE 35 LVE RVE 6 5 42 Normals 3 3 3 Groups with no infarction 10 12 6 28.6% 34.2% 1 2 1 6 9 15 4 3 2 3 1 1 1 2 4 1 1 1 1 3 2 4 35.7% Mean age of normals 71 yr. 6 36 25 yr. 3 3 1 8 1 1 4 2 4 15 Abbreviations: BVE = biventricular enlargement; LVE = left ventricular enlargement; RVE = right ventricular enlargement. anterior myocardial infarction group notching predominates in the X lead while in the postero-inferior group, predominance is in the Y lead. When more than one lead tied for the greatest number of notches, this is indicated. X and Y leads are heavily represented in biventricular enlargement, and in the group with spotty myocardial infarction there is almost an equal distribution through each of the leads. Notching, while less common, predominated in the Z lead in the combined group of normal subjects, though in the smaller subgroup of old normals it predominated in the X lead. It should be emphasized, however, that the autopsied normal subjects can be separated by notch count alone from those with biventricular enlargement, and from infarction subjects with a P value of less than 0.05, and the 36 "young normals" may be separated from the enlargement and infarction groups with a P value of less than 0.01. Thus, notch count remains very low even in the lead of predominance in both categories of normal subjects.15 Figure 1 illustrates the data distribution. It shows the number of notches per lead of each subject for the normal and the infarction Circulation, Volume XL, December 1969 groups. The normals tend to show peak distribution at the zero notch count with the count of 3 notches as the maximum for any lead. While there is overlap, the anterior group of infarctions are distributed about a relatively high mean notch count in lead X, while the subjects with postero-inferior infarctions show a high notch count in lead Y and peak at a relatively lower count in lead X. The spotty group is more equally distributed between leads X, Y, and Z. Table 2 shows the mean notch count for the leads X, Y, and Z (both individually and in combination) for each group. Note the low notch counts in the normal subjects and the groups with single ventricular enlargement. The infarction and biventricular enlargement groups all have high total counts. The predominance of notching in X in the anterior infarction group over the postero-inferior infarction group is significant with a P value of less than 0.05. Figure 2 shows examples of the standard ECG and XYZ leads of an 89-year-old man obtained 2 months prior to death. Less than 24 hours before death, the ECG was unchanged. None of the classic ECG features of myocar- FLOWERS ET AL. 930 x y z 20 NORMAL L-YOUNG Ut 15 c I10- 0 z ;.; "OLD" 5- 0 5 10 *INTRAMURAL LESIONS BREAKTHROUGH LESIONS INFARCTION POSTERO-INFERIOR 10 Downloaded from http://circ.ahajournals.org/ by guest on April 29, 2017 ANTERIOR SPOTTY 5i>-1 0 -~10 r 0 5 NOTCHES 10 5 ° 10 PER LEAD Figure 1 The data distribution is illustrated for the normal and infarction subjects. Note that the normals cluster toward the zero end of the scale with 3 notches as the maximal number reached in any lead. The anterior group is distributed about a relatively high mean notch count in X while the postero-inferior group shows a higher count in Y. The spotty group is more equally distributed in X, Y, and Z, and has relatively high counts. Table 2 Lesions by Group with Average Number of Notches per Lead and All Three Leads Combined No. of subjects Anterior Postero-inferior Spotty BVE LVE RVE Normal (old) Normal (young) 24 24 17 35 6 5 6 36 X Table 3 Notch Incidence in XYZ Leads in Intramural Infarctions Mean no. of notches by lead Y Z X+ Y +Z 3.2 2.9 2.0 3.0 3.8 3.8 3.5 4.1 1.2 2.0 1.2 1.4 2.3 1.7 0.6 1.1 2.9 1.9 3.8 3.2 2.0 1.2 1.5 9.0 6.9 11.4 10.8 5.2 3.8 5.5 1.4 3.1 Abbreviations same as in table 1. dial infarction were present in any set. The strict localization of high-frequency notching in the Y lead, however, pointed to a coalescent, old, intramural postero-inferior in- Anterior Postero-inferior Spotty No. of subjects X 7 11 16 4.1 2.1 3.8 Mean no. of notches by lead Y Z X+ Y +Z 3.4 3.0 4.0 3.3 2.0 3.8 10.8 7.1 11.6 farct, 2.5 by 1 by 0.5 cm, found at postmortem examination. In figure 3 is an example of an extensive intramural anteroseptal and postero-inferior infarction in a second patient, 66 years old, again with extensive notching in orthogonal leads X and Y, but only a questionably wide Q in X. In a third patient (fig. 4), the evidence for Circulation, Volume XL, December 1969 LOCALIZATION OF MYOCARDIAL SCARRING 931 12-27-65 SOmsec VI A 0m5L V2 \V3 V4 V5 V\; 20. S0 msec 20 3-14 -64 Downloaded from http://circ.ahajournals.org/ by guest on April 29, 2017 Figure 3 x Extensive notching in X and Y without diagnostic Q waves or other signs of infarction. Patient had extensive intramural anteroseptal and intramural posteroinferior scarring. y 12- 28- 65 Figure 2 The standard ECG (A) and orthogonal XYZ leads (B) of an 89-year-old man obtained 2 months prior to death. An ECG less than 24 hours before death was identical to its predecessor. Note the absence of classic diagnostic signs of infarction but the localized occurrence of high-frequency notching in the Y lead. At autopsy the patient had a coalescent, old inferior infarct confined to the intramural aspect. anteroseptal myocardial infarct is present classic QS complexes in VI to V3 in the standard ECG taken the last week of life. However, the only allusion to the inferior scarring also found at autopsy is suggested by the notching noted in the Y lead of the highfrequency recording taken 72 hours before death and possibly by the slurring on the downstroke in direct-writing leads II, III, and aViF. The classic lack of the normal anteriorly directed activation (no Q in Z) reflects the anteroseptal infarction. Table 3 indicates notch incidence in XYZ leads in intramural infarctions only. This table may be compared with table 2 which includes all groups. Note that in the intramural infarction group notches are frequent and appear in greatest number in the X lead with an as Circulation, Volume XL, December 1969 anterior intramural scars, in the Y lead with postero-inferior intramural scars, and are more equally distributed in X, Y, and Z in the spotty intramural infarctions. From table 4 it may be noted that slurring and notching of II, III, and aVF in the directwriting ECG are frequent in inferior myocardial infarction and may predict the information before the more classic signs are manifest. Table 4 ECG Direct-Writing Notching in Leads II, III, and aVF Postero-inferior Transmural Intramural Anterior Transmural Intramural No. of subjects Pre-Q notching* Post-Q notchingt No notching 13 11 7 8 5 0 1 3 17 7 7 5 6 0 4 2 * Pre-Q notching implies the presence of notching or slurring in leads II, III, and aVF prior to other ECG or VCG diagnostic evidence of infarction. t Post-Q notching includes patients who developed notching only after the development of other classic ECG or VCG criteria of infarction. Patients in whom chronologic relationship between the occurrence of notching and the development of significant Q waves was not known, but in whose recordings both are present, were included in this group. FLOWERS ET ALr 932 anLterior infarction as well, We do not have a large enough group of autopsied "old normals" to make a valid statement regarding incidence of pre-Q notching in that group. Notching occurred in eight of the 36 "young normals" who had high-frequency VF leads run. Though many correlations were attempted, table 5 summarizes those of greatest signifi cance. In the body of the text certain highly significant correlations previously made are noted.'5 2t i -10-66 Vr A VI V2 /4 V3 EIVI %t cNf \; 0.5 Downloaded from http://circ.ahajournals.org/ by guest on April 29, 2017 x y 1-14-66 Figure 4 V1 to V, indicates standard EGG this 68-year-old-man (A). The absence of a Q wave in Z also points to the anteroseptal lesion (B). The only suggestion, however, of the intramural inferior in- The well-known QS complex in the anteroseptal infarction in the of farction also found at autopsy is the notching and slurring in II, 111, and aVp (A) and the prominent notching in the high-filelity Y lead (B). However, the value of this observation is limited when it is realized that notching is also frequent in one or more of these leads in Discussion It seems, then, that there is some localization value in noting the lead of greatest occurrence of high-frequency components. Especially useful is this relationship when a diagnostic Q wave is absent In the case of nontransmural infarction the only hint may be an increased incidence of notching in specific leads. It is logical that the lesions that are i-noie nearly along the Y axis, as in the case of postero-inferior lesions, wouild manifest in creased notching in Y. Anterior lesions, however, express themselves predominantly in lead X. It is difficult to understand why notching is not also strongly expressed in the anteriorly oriented Z lead in anterior infarction. Perhaps the reason relates to the fact that while 11 of 24 postero-inferior infarctuons were intramural, only seven of '24 anterior lesions were confined to the ininer wall. In general, the anterior infarctions were larger than the postero-inferior ones. These two Table 5 Significant Correlations* Postero-inferior infarction Notching in Y > notching in X Notching in Y > notching in Z X lead notching X notching in anterior infarction > than in postero-inerior Young normals Notching in Y > rLotching in X Notching in Z > notching in X <0.01 P < 0.025 P P <0.025 P < 0.025 P <0.001 * Note predominance of Y notching over X and Z notching in postero-inferior infarction X notching is significantly greater in anterior infaretion as compared with postero-inferior infarction. Young normals show notching predominating in Z and Y over X, but in each case a very small total notch count (average 3.1 notches for X + Y + Z)2 Cc4eatsorn, Volume XL December 1969 LOCALIZATION OF MYOCARDIAL SCARRING Downloaded from http://circ.ahajournals.org/ by guest on April 29, 2017 observations suggest that high-frequency notching in infarction probably originates from areas peripheral to the main coalescent scar in transmural infarction where spottily interrupted conduction may occur. In the larger, and more frequently transmural, anterior lesions these peripheral areas may spill over laterally or along the X axis while the Z axis senses an electrically silent area. In the relatively smaller, more frequently intramural postero-inferior lesions the peripheral or fringe zone of impaired conduction still lies predominantly along the Y axis. We want to point out again that highfrequency notching in infarction may be simply an earlier stage of Purkinje block as originally described by Oppenheimer and Rothschild, a stage prior to QRS prolongation and detectable only with high-frequency recording technics.15' 21 The lower frequency notching (greater in frequency than the basic QRS but below 100 cps) seen on the descending limbs of directwriting leads II, III, and aVF are intriguing and seem frequently to accompany infarction, both transmural and intramural. This type of slur or notch of relatively lower frequency than that detectable in a high-frequency system offers some diagnostic help but is of limited aid to localization. This is mainly true because of the high incidence in anterior as well as posterior infarction. We would like to emphasize the need of a convenient, frictionless recording system above a frequency response of 500 cps and a sweep speed of 250 mm/sec. We believe a source of early diagnostic, prognostic, and screening information may be otherwise untapped. It appears that Durrer's and later Langner's experimental studies of induced local myocardial injury in dogs may be borne out in the clinical situation; but because high-frequency notching may point to other myocardial abnormalities, rather than to intramural scarring, it is most helpful to have eliminated biventricular enlargement as a cause by roentgenograms, careful history and physical exCirculation, Volume XL, December 1969 933 amination.15-17 The greatest clinical fruitfulness in infarction appears to be in diagnosing and localizing scars in the small heart, with intramural lesions and an absence of the usual ECG evidence of infarction. These may have high notch counts not clouded by the increased notch counts expected in ventricular enlargement. In these cases, the leads may offer some pertinent information as to localization of scars as well as to simply announce their presence. References 1. LANGNER, P. H.: The value of high fidelity electrocardiography using the cathode ray oscillograph and an expanded time scale. Circulation 5: 249, 1952. 2. LANGNER, P. H.: High fidelity electrocardiography: Further studies including the comparative perfonnance of four different electrocardiographs. Amer Heart J 45: 683, 1953. 3. LANGNER, P. H.: Further studies in high fidelity electrocardiography: Myocardial infarction. Circulation 8: 905, 1953. 4. LANGNER, P. H., AND GESELOWITZ, D. B.: Characteristics of the frequency spectrum in the normal electrocardiogram and in subjects following myocardial infarction. Circulation Research 8: 577, 1960. 5. LANGNER, P. H., AND GESELOWITZ, D. B.: First derivative of the electrocardiogram. Circulation Research 10: 220, 1962. 6. LANGNER, P. H., GESELOWITZ, D. B., AND MANsURE, F. T.: High frequency components in the electrocardiograms of normal subjects and of patients with coronary heart disease. Amer Heart J 62: 746, 1961. 7. LANGNER, P. H.: Serial change in high frequency electrocardiograms: A 10-year follow-up. Presented at the Cardiac Electrophysiological Group meeting, Atlantic City, N. J., May 31, 1964. 8. LANGNER, P. H., AND LAUER, J. A.: Relative significance of high-frequency and low-frequency notching in the electrocardiogram. Amer Heart J 71: 34, 1966. 9. BURCH, G. E., HoRAN, L. G., ABILDsKov, J. A., AND CRONVICH, J. A.: A study of the spatial vectorcardiogram in subjects with posterior myocardial infarction. Circulation 12: 418, 1955. 10. BURCH, G. E., HoRAN, L. G., ZISKIND, J., AND CRONVICH, J. A.: Correlative study of postmortem electrocardiographic and spatial vectorcardiographic data in myocardial infarction. Circulation 18: 325, 1958. 934 FLOWERS ET AL. 11. BURCH, G. E.: Clinical applications of vectorcardiography. The Long Island Jewish Hospital Symposium on Vectorcardiography, Queens, New York, May 11-13, 1965. 12. SELVESTER, R. H., RUBIN, H. B., HAMLIN, J. A., AND PATE, W. W.: New quantitative vectorcardiographic criteria for the detection of unsuspected myocardial infarctions in diabetes. Downloaded from http://circ.ahajournals.org/ by guest on April 29, 2017 Amer Heart J 75: 335, 1968. 13. PIPBERGER, H. V., AND CARTER, T. N.: Analysis of the normal and abnormal vectorcardiogram in its own reference frame. Circulation 25: 827, 1962. 14. REYNOLDS, E. W., MuLLER, B. F., ANDERSON, G. J., AND MULLER, B. T.: High-frequency components in the electrocardiogram: A comparative study of normals and patients with myocardial disease. Circulation 35: 195, 1967. 15. FLowERs, N. C., HoRAN, L. G., THoMAs, J. R., AND TOLLESON, W. J.: The anatomic basis for high-frequency components in the electrocardiogram. Circulation 39: 531, 1969. 16. DuBIER, D., VAN LIm, A. A. A., AND BULLER, J.: Epicardial and intramural excitation in chronic myocardial infarction. Amer Heart J 68: 765, 1964. 17. LANGNER, P. H., DEMoTr, T., AND HussEY, M.: High-fidelity electrocardiography: Effects of induced localized myocardial injury in the dog. Amer Heart J 71: 790, 1966. 18. MCFEE, R., AND PARUNGAO, A.: An orthogonal lead system for clinical electrocardiography. Amer Heart J 62: 93, 1961. 19. GEsELowITz, D. B., LANGNER, P. H., AND MANSURE, F. T.: Further studies on the first derivative of the electrocardiogram, including instruments available for clinical use. Amer Heart J 64: 805, 1962. 20. SNEDECOR, G. W.: Statistical Methods. Ames, Iowa, The Iowa State University Press, 1956. Chapters 4 (p. 85) and 9 (p. 212). 21. OPPENHEIMER, B. S., AND ROTHSCHILD, M. A.: Electrocardiographic changes associated with myocardial involvement. JAMA 69: 429, 1917. Savoring the Thoughts of Writers The purpose of reading is not to gobble up the words-even though the reader can afterward itemize his intake from memory-but to experience a mood, to meander through thoughts touched off by an idea, to provide food for the imagination. What makes the present emphasis on rapid reading all the more baleful is that it occurs in the context of an age that worships speed. The consciousness needs the kind of breather the book can provide. It is absurd to say that the speed-readers, if tested, will be able to give everything back. This is not reading; it is regurgitation. What speed-readers too often can't give back is the beauty of a line or the melody of a thought.-From NORMAN COUSINS: Editorial: Books and Transplants. Saturday Review (July 5) 18, 1969. Circulaton, Volume XL, December 1969 Localization of the Site of Myocardial Scarring in Man by High-Frequency Components NANCY C. FLOWERS, LEO G. HORAN, W. J. TOLLESON and J. R. THOMAS Downloaded from http://circ.ahajournals.org/ by guest on April 29, 2017 Circulation. 1969;40:927-934 doi: 10.1161/01.CIR.40.6.927 Circulation is published by the American Heart Association, 7272 Greenville Avenue, Dallas, TX 75231 Copyright © 1969 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/40/6/927 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. 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