Vectorcardiographic Evaluation of Postoperative Changes in Patients with Interatrial Septal Defect: a Review of 55 Cases M

Home , Cardiac catheterization

Canad. Med. Ass. J. 1340 Chabot and others: Vectorcardiographic Evaluation Dec. 25,1965, vol. 9J Vectorcardiographic Evaluation of Postoperative Changes in Patients with Interatrial Septal Defect: A Review of 55 Cases M. CHABOT, M.D.,* A. KARAMEHMET, M.D.,t M. BOURASSA, M.D. and P. DAVID, M.D.,$ Montreal

ABSTRACT SOMMAIRE The pre- and post-operative vectorcardio- Nous avons etudie les vectocardiogrammes of 55 with atrial septal defect de 55 patients souffrant d'un defaut de la grams patients avant et l'o¬ (ASD) are discussed. Forty-nine were of cloison interauriculaire, apres ostium secundum type and six of ostium peration. Quarante-neuf cas etaient des primum type. The criteria used to study defauts de type ostium secundum et six cas the of ventricular de type ostium primum. Dans le plan hori¬ regression right hyper¬ des forces trophy were: in the horizontal plane, the zontal les rapports anterieures/ ratio of anterior-over-posterior forces, the posterieures et droites/gauches, ainsi que right-over-left forces and the rotation of les variations du sens de rotation nous ont the body of the QRS loop; in the frontal servi de criteres pour apprecier la regression plane, the direction of half-area vector. Us¬ de Thypertrophie droite. Dans le plan fron¬ ing these criteria, 46 out of 49 patients with tal, la direction du vecteur de demi-surface defects of the ostium secundum type had fut le critere utilise. vectorcardiographic evidence of regression Chez les 49 malades porteurs d'une ano- of right ventricular hypertrophy. Marked malie de type secundum, 46 montrerent clinical improvement was also demonstrated une regression de Thypertrophie ventri¬ in all these patients. The three patients in culaire droite au vectocardiogramme. A ces whom was not demonstrated donnees vectorielles correspondait une ame- improvement Chez trois on the vectorcardiogram had persistence of lioration clinique significative. non il a cardiac defect. Following surgery two patients ameliores vectoriellement, y children with ostium defects avait persistance d'anomalie cardiaque. primum d'un de showed no change in the frontal plane, Chez deux enfants porteurs defaut whereas in the horizontal plane a normali- type ostium primum, nous avons observe zation of vectorial forces was observed. peu de changement dans le plan frontal malgre une normalisation du plan hori¬ zontal.

and vectorcardio¬ ELECTROCARDIOGRAPHICgraphic studies of the depolarization process of the heart clues to the cardiovascular dynamics tend to return to normal, may provide important the anatomic due to IASD ven¬ diagnosis of the anatomical lesion underlying many changes (right cardiac defects. Cardiac catheterization tricular hypertrophy or dilatation) are also ex¬ congenital to toward normal.1' 3 The VCG has and corrective surgery have also afforded the op- pected regress portunity for correlation of the electric, hemody¬ been advocated as a simple method to determine namic and anatomic findings in patients with these the adequacy of closure of the defect. defects. The of the electrical The purpose of this report is to evaluate the cor¬ diagnostic importance relation of with phenomena, especially in cases of interatrial septal the vectorcardiographic changes defect (IASD) of both the secundum and primum the clinical improvement observed after surgical a with has been demonstrated by many authors. In correction in group of patients interatrial types, defect studied at the Montreal Heart In¬ a recent publication, the vectorcardiogram (VCG) septal was reported to give more information than the stitute. standard 12-lead electrocardiogram (ECG): in some cases of IASD in which the ECG was con¬ Material sidered, on reasonable grounds, to be within normal The files of patients who had had a vector¬ limits, the presence of the lesion was suggested by cardiogram before and after surgical correction of the VCG.11 After surgical correction, when the IASD were reviewed. There were 55 such cases, and in all the diagnosis was confirmed by hemo¬ From the Montreal Heart Institute, 5415 Blvd. de TAssomp¬ tion, Montreal 36, P.Q. dynamic studies and at surgery. Patients with ac- ?Chief. Department of Electrocardiography and Vector- cardiography, Montreal Heart Institute. companying defects such as coarctation of the tPresent address: Hacettepe Medical Center, Ankara, interventricular aortic valve Turkey. aorta, septal defect, $Director, Montreal Heart Institute. disease, patent ductus arteriosus or pulmonic ste- Canad. Med. Ass. J. AND OTHERS: VECTORCARDIOGRAPHIC EVALUATION 1341 Dec. 25, 1965, vol. 93 CHABOT nosis were excluded. Forty-nine patients had de¬ fects of the "secundum" type and six had defects of the "primum" type. Thirty-six cases of ostium secundum were uncomplicated; nine also had par¬ tial anomalous pulmonary venous return, one mitral stenosis, two minimal mitral insufficiency and one an unruptured aneurysm of the sinus of Valsalva. The ostium secundum group consisted of 40 females and nine males. There were two females and four males in the ostium primum group. The age of the patients ranged from 4 to 44 years when the first (preoperative) VCG was taken (Fig. 1). A FORCES T0 THE RIGHT NUMBER B FORCES T0 THE LEFT OF CASES C ANTERIOR FORCES D POSTERIOR FORCES

Fig. 2..Measure of the anterior, posterior, right and left forces (see text for detail.)

the postoperative VCG a decrease of more than 20% over the initial value of this ratio is considered as indicative of improvement. 2. The X axis (right-left) is also determined on the horizontal plane. From two points most an¬ teriorly and posteriorly on the QRS loop, perpen¬ 4-9 10-19 20-29 30-39 >40 years diculars are drawn to the X axis. Anterior and OSTIUM SECUNDUM OSTIUM PRIMUM posterior forces and their ratio are calculated in the Fig. 1..Distribution of patients according" to age. same way. A decrease of more than 20% over the preoperative value is considered indicative of im¬ The VCG's were recorded between provement. postoperative 3. With to the direction of of two weeks and six after most of respect inscription years surgery, a from them taken between six months and the loop in the horizontal plane, change (49) being clockwise to or from two 15 had more figure-of-eight configuration, years postoperatively; patients figure-of-eight to counterclockwise, is considered than one postoperative VCG study. indicative of were taken with a Sanborn vector improvement. The VCG's 4. In the frontal the half-area vector is and and recorded with a plane amplifier visoscope, measured. A shift to the left of more than 30° Technica camera on Kodak Super Panchro-press is considered indicative of 4 x 5 inch film. The cube reference improvement. (This type B, system criterion was suitable in cases of ostium secundum of Grishman was utilized. The beam was inter¬ 400 times the rounded end of only.) rupted per second, these four we classified the tear drops indicating the direction of inscription Using criteria, degree of the of improvement shown in the postoperative VCG's loop. as or under vision was 0, +, ++, +++, ++++. Surgical correction direct per¬ of the inferior and forces did formed in all cases by Drs. Pierre Grondin, Gilles Study superior Lepage and Jean-Louis Lamy. not show any significant change; the maximum vector in the frontal plane had a large scatter, and Methods the deviation after surgery was also not significant. Though they were measured in each case, these Four criteria were used to determine the re¬ parameters were not included in the study. gression of the right ventricular hypertrophy: 1. The Z axis (anteroposterior) is determined on Results the horizontal From two situated maxi¬ plane. points Ostium Secundum mum to the right and maximum to the left on the QRS loop, perpendiculars to this axis are drawn 1. The average of right over left forces decreased (Fig. 2). Forces to the right and forces to the left from 0.93 to 0.32 (Table I) after surgery. Forty- are measured (in mv.) and the ratio of forces two of 49 cases presented a decrease of more than to the right to forces to the left is calculated. In 20%; six showed no change or a change of less than Canad. Med. Ass. J. 1342 Chabot and others: Vectorcardiographic Evaluation Dec. 25, 1965, vol. 93

TABLE I..Ostium Secundum 4. The mean of half-area vectors in the frontal Forces to right (mr.) Forces to left (mv.) Right/left plane was 97° before surgery (15-220°). Following Before After Before After Before After the was the Average. 0.59 0.25 0.91 1.01 0.93 0.32 surgery, average 38°, range varying Range.0.15-2.70 0.03-0.50 0.27-2.10 0.56-2.14 0.16-3.84 0.03-1.83 from 335° to 105° (Fig. 5). In 32 patients the half- Anterior forces (mv.) Posterior forces (mv.) Ant./post. area vector had shifted to the left more than 30°. Before After Before After Before AfUr There was no shift to the right after surgery (Fig. Average. 0.73 0.44 0.14 0.17 3.96 2.64 4). Range.0.12-2.12 0.06-1.40 0-0.87 0-0.68 0.47-9.30 0.40-9.50 oo in 19 °° in 7 cases cases

20% ; and only one patient presented a negative re¬ sult, i.e. augmentation of the forces to the right after surgery. He was noted to have a systolic murmur at the left sternal border during the early post¬ operative period. Unfortunately he was lost to follow-up, and a further control study could not be obtained. 2. The average of anterior over posterior forces decreased from 3.96 to 2.64 after surgery. The ratio of anterior forces was equal to infinity in 19 cases before surgery and in seven after surgery. These cases were omitted when the average value was calculated. In 34 cases there was a decrease of more than 20%; 15 had changes of less than 20%. In six of the seven cases having no posterior forces (anterior over posterior forces = co) before and after surgery, the amplitude of the anterior forces significantly diminished after surgery. + CONTROL 15° 220° MEAN 97° BEFORE SURGERY AFTER SURGERY . AFTER SURGERY 335° 105° 10* MEAN 38° Fig. 4..Orientation of the half-area vectors in the frontal COUNTER plane (ostium secundum). CLOCKWISE By assigning one -f- for each criterion that FIGURE-0F- showed improvement the following results were observed: (0) three patients, ( + ) i°ur patients, ( + +) seven patients, (-|.|.f- ) 21 patients, (++++) 14 patients. CLOCKWISE When a patient had more than one postopera¬ tive VCG, the values of the last tracing were in¬ GENERAL SHUNT SHUNT GENERAL SHUNT SHUNT cluded in the results. >60% < 60% >60% <60% Fig. 3..Rotation in horizontal plane (ostium secundum), 49 cases. Ostium Primum 1. The average of right over left forces decreased 3. Rotation of the body of the QRS loop in the from 0.54 to 0.33 (Table II). Two of six patients horizontal plane showed the following changes in showed changes less than 20%. In one, the VCG 30 cases: (a) from clockwise to figure-of-eight, six was done only 2y2 months after surgery; clinical cases; (b) from clockwise to counterclockwise, 10 evaluation 10 months later revealed satisfactory cases; (c) from figure-of-eight to counterclockwise, improvement. In the second case the murmur per- 14 cases. In 19 cases there was no significant change sisted after surgery. A hemodynamic study six after surgery (including five who already had counterclockwise rotation preoperatively). Of the TABLE II..Ostium Primum five cases presenting a normal counterclockwise Forces to right (mv.) Forces to left (mv.) Right/left rotation before surgery, all had a shunt flow which Before After Before After Before After was less than 60% of the pulmonary flow. Patients Average. 0.58 0.34 1 09 1.14 0.54 0.33 with shunts of more than 60% of the pulmonary Range.0.20-0.95 0.03-0.64 0.72-1.50 0.78-1.70 0.28-1.05 0.02-0.62 flow had either a clockwise or figure-of-eight in¬ Anterior forces (mv.) Posterior forces (mv.) Ant./post. scription of the loop. The difference between the Before After Before After Before After two after correction Average 0.80 0.40 0.25 0.47 2.36 2.03 groups disappeared surgical Range.0.12-1.20 0.04-1.06 0-0.62 0-150 0.50-8.00 0.36-7.57 (Fig. 3). oo in 1 case oo in 1 case Canad. Med. Ass. J. and others: Vectorcardiographic Evaluation 1343 Dec. 25, 1965, vol. 93 Chabot H h . a-)&z7. ^.

X10 BEFORE ^V^^t

-; X10 AFTER

5b Figs. 5a and b..Normalization of the VCG after surgical correction (ostium secundum).

correction of her IASD. However, she continued to have symptoms and her heart remained enlarged. months later demonstrated the presence of a The auscultatory findings of mitral stenosis per¬ significant left-to-right shunt. None of these pa¬ sisted and it was felt that she had either an in¬ tients showed an increase in the forces to the right adequate commissurotomy or restenosis. One pa¬ after surgery. tient with an ostium primum (OP) defect, already 2. The average of anterior over posterior forces mentioned, had a large shunt also after surgery. decreased from 2.36 to 2.03. The patient mentioned His VCG six months later was unchanged. One previously, in whom the shunt persisted after sur¬ patient with an ostium secundum (OS) defect also gery, had no change in A/P forces. The patient who had no change two years after surgery; however, had a VCG 2y2 months after correction of his defect this patient was lost to follow-up and we have no showed a decrease in anterior forces. One patient further information about him (his was the case had no posterior forces before and three years after with increased forces to the right after surgery). surgery. In four patients with OS defects the VCG re¬ 3. In two patients the rotation of the loop in the verted to normal after surgery (Figs. 5a, b). None horizontal plane became counterclockwise after of these had a completely normal VCG before surgery. The patient with persisting shunt had a surgery, probably because they represent a clockwise rotation before and after surgery. In two selected group for whom surgery was indicated. patients the change in the inscription of the loop Two patients with OP defects had normalization was not considered sufficient to justify a -\- grading. of the horizontal plane loop. The frontal plane One patient had counterclockwise rotation before loops were practically unchanged in these cases and after surgery. (Figs. 6a, b). By assigning one -\- for improvement in each of In all cases in which definite slowing of more three criteria, the following results were observed: than 0.3 see. (12 dots) in the terminal inscription (0) one patient, (-)-) one patient, (-|.|-) three of the loop was present, this configuration per¬ patients, (-|.1-+) one patient. sisted in the postoperative VCG. In the entire group, five postoperative VCG's (in Patients who were considered improved on clini¬ four patients) showed no improvement. One pa¬ cal examination also had VCG's showing improve¬ tient had her control VCG taken only two weeks ment (90% of grade -\.f- or more). after surgery. She also had mitral stenosis, and The vectorcardiographic changes began about commissurotomy was done at the time of the two to three months after surgery and occurred Canad. Med. Ass. J. 1344 Chabot and others: Vectorcardiographic Evaluation Dec. 25,1965, vol. 93 fc~H >-a

\ / U\ iS X20 BEFORE X10 BEFORE

A S V h> w ! . V.N //\ . X10 AFTER 6b X10 AFTER Figs. 6a and b..Changes of the horizontal plane after 6a surgery in two cases of ostium primum. Discussion mostly during the first year (Fig. 7). Since there were many children in the series (13 patients were The VCG and ECG in cases of interatrial septal less than 10 years old), it was difficult to determine defect have been studied by others and found to when the changes due to surgery had ceased to be of importance in the diagnosis of this lesion.2' 6 occur, in view of the fact that the VCG in normal The correlation of the electrical configuration with persons of this age also shows changes as they hemodynamic data is, however, more controversial. grow older. In adults the vectorcardiographic De Oliveira and Zimmerman13 found a good cor¬ changes were minimal after one year (three cases). relation between the shunt flow and the height of the R wave in lead Vx. On the other hand, Barboza, Brandenburg and Swan17 found no precise quanti¬ tative correlation between the two methods. Liebman and Nadas12 demonstrated a better cor¬ ratio of NUMBER OF VCG relation between the VCG and the right- z to-left ventricular work. In several reports10' n»14,19 111 17 it is also noted that cardiac catheterization or re- 2 +++ IXI operation has demonstrated the persistence of a > shunt when the electrical abnormalities were not o ++ altered after surgery. The criteria for the diagnosis of right ventricular +h hypertrophy, in the cube reference system of vectorcardiography, have been well standardized the work of Grishman and Scherlis.9 However, P0ST0P by s*> .«>* «** ^ they were not found suitable for the quantitative «**>*.*'"\' .3 b* v -7- evaluation of the changes in any one patient. The MEAN IMPROVEMENT vectorial forces to the right, to the left, anteriorly Fig. 7..Ostium secundum, 49 cases (63 VCG). and posteriorly were studied by Liebman and Canad. Med. Ass. J. Dec. 25, 1965, vol. 93 CHABOT AND OTHERS: VECTORGARDIOGRAPHIC EVALUATION 1345

Nadas'2 in normal children and in patients with (i.e. block of the anterior superior branch of the IASD. They found, in cases of IASD, an increase left bundle), was taken by Toscano-Barbosa, of right and anterior forces, a decrease of posterior Brandenburg and Burchell'8 and others.'2 forces and no significant change of left forces. The normalization of the horizontal plane, to- These parameters, together with the combination gether with the clinical improvement in the ab- of the ratios of right-over-left and anterior-over- sence of changes in the frontal plane, has led us posterior forces, have been very useful in evalu- to believe that the left orientation is not a factor in ating the postoperative changes in our patients. left ventricular hypertrophy. Our control findings are comparable to those in their patients with IASD, and our postoperative SUMMARY AND CONCLUSIONS results tend to approach the values of their normal Fifty-five cases of interatrial septal defect are pre- cases. The criterion of a 20% increase or decrease sented. All had vectorcardiograms before and after was adopted empirically, after consideration of the surgery. changes due to respiration and electrode place- Patients who were considered improved clinically ment. showed signs of regression of right ventricular hyper- The advantages of studying the half-area vectors trophy in their vectorcardiograms. instead of maximum vectors have been demon- Patients demonstrating no changes in the vector- strated by Bristow5 and by Pipberger.'5 The cardiograms at least three months after surgery had a persistence of shunt or some secondary cardiac path- maximum vector is the value of an instantaneous ology. force, without considering the result of the loop. In patients with ostium secundum defects the vector- The half-area vector is affected by the whole loop cardiogram may become completely normal after sur- and shows more uniformity in a group of cases gery. In those with ostium primum defects the hori- with the same pathology. This was true also in our zontal plane may become normal but the frontal plane series. maintains its configuration. The clockwise rotation in the horizontal plane, The vectorcardiogram seems to be a reliable method an important criterion of right ventricular hyper- for postoperative evaluation of patients with interatrial trophy (using the Grishman cube system), was septal defect. affected by surgery in cases of ostium secundum REFERENCES as well as in those with ostium primum defects. 1. BEREGOVICH, J. et al.: Amer. Heart J., 59: 329, 1960. 2. Ideni Circulation, 21: 63, 1960. Counterclockwise rotation in the frontal plane in 3. BLOUNT, S. G., JR. et at.: Ibid., 9: 801, 1954. the cases of ostium primum defect 4. BLOUNT, S. G., JR., BALCHUM, 0. J. AND GENSINI, G.: did not change Ibid., 13: 499, 1956. at all after surgery. Fig. 6a shows the normaliza- 5. IiRisTOw, J. D.: Amer. Heart J., 61: 242, 1961. 6. BURCH, G. E. AND DEPASQUALE, N.: Ibid., 58: 319, 1959. tion of the horizontal plane in a case of OP defect, 7. CAMPBELL, M. AND MISSEN, (}. A. K.: Brit. Heart J., 19: 403 1957. with no significant change in the rotation or con- 8. COOLEY, D. A. AND MCNAMARA, D. G.: Proyr. Cardiov. Dis., 1: 89, 1958. figuration of the frontal plane. 9. GRISHMAN, A. AND SCHERLIS, L.: Spatial vectorcardiography, W. B. Saunders Company, Philadelphia 1952. The orientation to the left and somewhat 10. HAHN, C. AND RISCH, F.: Cardiologia (Basel), 34: 265, superiorly of the QRS loop 1959. and the counterclock- 11. LEE, Y. C. AND SCHERLIS, L.: Circulation, 25: 1024, 1962. wise rotation in the frontal plane are present in a 12. LIEBMAN, J. AND NADAS, A. S.: Ibid., 22: 956. 1960. 13. DE OLIVEIRA, J. M. AND ZIMMERMAN, H. A.: Amer. Heart very high percentage of patients with an endo- J., 55: 369, 1958. 14. MILNoR, W. H. AND BERTRAND, C. A.: Amer. J. Med., 22: cardial cushion defect. Left ventricular hyper- 223 1957. 15. PIUBERGER, H. V.: Circulation, 16: 926, 1957 (abstract). trophy secondary to a mitral cleft was considered 16. SILVERBLATT, M. L. et at.: Amer. Heart J., 53: 380, 1957. 17. BARBOZA, E. T., BRANDENBURG, H. 0. AND SWAN, H. J. C.: to be the cause of this orientation by some Amer. J. Cardiol., 2: 698, 1958. 18. TOsCANO-BARIIoSA, E., BRANDENBURG, H. 0. AND BURCHELL, authorsi . 8, 14 A different view, based on altera- H. B.: Proc. Mayo Clin., 31: 513, 1956. tions in the excitation pathways into the ventricles 19. WALKER, W. J. et at.: Amer. Heart J., 52: 547, 1956.

PACES OUT OF THE PAST: FROM THE JOURNAL OF FIFTY YEARS AGO THE OBJECT OF TRANSFUSION forming organs. Intravenous saline injections, however, are useful only where the organs are already in good condition There have been various opinions as to why transfusion and can withstand the immediate and violent stimulation should be beneficial, and in the estimation of many the of a large volume of fluid. The object of transfusion, then, mere volume of blood explained the improvement. For is to provide those morphological elements and active princi- this reason it was held that the use of transfusion had impaired no advantage over the intravenous injections of saline ples from the donor which can improve the solutions. But here again modern kematology has demon- metabolism of the recipient and stimulate his cells and strated that blood formation is stimulated by the introduc- kemopoietic organs. This is all transfusion is expected to tion of new blood, so that transfusion has obtained an added accomplish, for it neither rejuvenates old organs, nor repairs importance. After all, the object of transfusion is to attain diseased tissues, though it affords them time to regain their a safe, rapid and simple mode of restoring the volume of loss and to add a stimulus to their new growth-Editorial, blood, but more especially its regeneration in the blood- Canada. Med. Ass. 1., 5: 1084, 1915.