Pediat. Res. 3: 210-216 (1969) Arrhythmia heart congenital heart vena cava disease Abnormal Rhythms Associated with Persistent Left Superior Vena Cava KAZUO MOMMA[47] and LEONARD M. LINDE Division of Cardiology, Department of Pediatrics, University of California School of Medicine, Los Angeles, California, USA f:<-xtract The electrocardiograms of 26 patients with persistent left superior vena cava (SVC) draining into the coronary sinus were reviewed. Left axis of P waves between + 15 and - 29 degrees was observed in nine cases, including two of three cases of persistent left SVC with absent right SVC. Isorhythmic A-V dissociation with interference was observed in one subject. The study of the P wave in five groups of patients with presumably normal caval drainage revealed that frontal P wave axis fell usually between +20 and + 70 degrees. Speculation Left axis of the P waves, if present in patients with congenital heart defects, may suggest persistent left superior vena cava draining to the coronary sinus. Further pathologic and histologic study is needed to clarify the pathogenesis of these abnormal cardiac rhythms and the possible embryologic relation between persistent left superior vena cava and an ectopic pacemaker. Introduction This report describes the frequency and types of abnormal rhythms found in patients with persistent Abnormal rhythms occur in some patients with con­ left SVC draining to the coronary sinus and the electro­ genital heart disease. Coronary sinus rhythm, nodal cardiographic features that may be helpful in diagnosis rhythm, wandering pacemaker, atrioventricular dis­ of anomalies of superior vena caval drainage. sociation and left atrial rhythm have been reported [6,7,19,21,22,25,27,28]. These abnormal rhythms have been observed mainly in patients with complex Material and Methods cardiac anomalies accompanied by dextrocardia [17, 23,27], levocardia with abdominal situs inversus [6, 7, Twenty-six patients with persistent left SVC draining 25, 26] or anomalies of the venae cavae [11]. Since into the coronary sinus were studied at the University pacemaker tissue develops next to the junction of the of California Medical Center at Los Angeles from 1960 superior vena cava (SVC) and the right atrium [29], to 1967. Of the 26, 12 were males and 14 were females. abnormal rhythms associated with congenital heart Ages ranged £i'om fi ve days to 15 years; all had nor­ disease may be related to embryologic abnormalities mally placed hearts. The major cardiovascular mal­ in development and location of the superior vena cava. formations present in these patients and clinical and electrocardiographic data are tabulated in table I. All wave axes of normal children were between +40 and patients had congenital heart disease in addition to +60°. The mean frontal plane P wave axis of these persistent left SVC. Anomalies were confirmed by groups was 38". portmortem examination of 5 patients and by operation The transverse plane P wave axes of the electro- or cardiac catheterization of 2 1 patients. The criteria cardiograms of these groups showed rather wide varia- of KEITH[I 71 were used to determine the atrial posi- tion and were between -10 and + 90' (fig. 4). tion; the right atrium is the chamber that receives the venae cavae and the coronary sinus, or a majority of Electrocardiographic data: The mean frontal plane P these. All patients had normally situated atria. Cardiac wave axis was 22". Nine patients showed P waves of malformations included 10 patients with ASD, eight left axis (table I, figs. 1 and 2). Frontal plane P wave with tetralogy of Fallot and five with VSD. axes in these nine patients were between + 15 and Thirteen lead (including V3K) electrocardiograms -20°, and transverse plane P wave axes ranged from on all patients were studied. Tracings were obtained +80 to 0'. Signs of left atrial hypertrophy (deep ter- before operation and before administration of digitalis with the exception of patient No. 8. Electrocardiograms of this patient were available only during administra- tion of digitalis (table I). All ECG records were exa- mined for transient abnormal rhythms. The P waves I II 111 AVR AVL AVF were examined for height, duration, frontal plane axis, transverse plane axis, and configuration, particularly in leads V,, V,, V,, and V,. The P-R interval was noted with regard to age and heart rate. The established electrocardiographic criteria [3, 161 for nodal rhythm, A-V block and A-V dissociation were followed in this study. Frontal plane P wave axis was determined bv use of the triaxial reference frame [20]. Transverse plane P wave axis was deter- "1 "2 "3 "4 "5 "6 mined using reference frames suggested by Mirowski Fig. I. Electrocardiogram of a 2-year-old boy with ASD [2 11. Those regular P waves with normal P-R interval and normal rate were grouped according to the frontal (Ostium secundum persistent left SVC draining into the coronary sinus and absent right SVC. The plane axis as follows : frontal plane P wave axis is approximately -20' (case A. Extreme left axis (or coronary - 89 to 300 sinus rhythm [33]) 2). B. Left axis - 29 to + 15" C. Intermediate axis + 16 to + 75" -150 - H Mean D. Vertical axis 76 to 105" + + - 120 - E. Right axis (or left atrial + 106 to +270° rhythm [36]) ,-90 - (U As a control, the P wave was studied in five groups g-60 - of patients with presumably normal caval drainage u0 ;-30 - that had been studied by cardiac catheterization and .- X ...." angiocardiography. These groups, selected because ; 0- _ _ - - _ .- - ._ _ ._ _ - _ .. _ - - - - - - -- - - - - - - . they exhibited the most common lesions associated 7 +30 - . 11 v. "' 7-Y". with abnormalities of venae cavae, included 13 patients a ... ..." .. 3 " with ostium secundum atrial septal defect (ASD), 10 - +60 - .. 0 with ventricular septal defect (VSD), 10 with complete k +90 - A-V canal, 11 with tetralogy of Fallot and 11 normal I I I I I I children without heart disease. LSVC toCS ASD VSD CAVC TF Normal Fig.2. The frontal plane P wave axis of the electro- Results cardiogram in six groups of patients showing a high incidence of left axis of P waves (less than 15' or inverted The frontal plane P wave axes of the control groups in lead 111) in patients with persistent left SVC drain- were between +20 and 1-70 degrees, except in the ing into the coronary sinus. Two broken lines show two patients with ASD (fig.2). All frontal plane P normal upper and lower limits. Table I. Twenty-six cases with persistent left superior vena cava draining into the coronary sinus Patient Age Sex Congenital anomalies Rhythm PR HR P-axis Diagnosis No. (years) Front Trans. by tetralogy of Fallot, absent right SVC, anomalous right R (B) 0.15 120 -10 subclavian artery .................. ASD, absent right SVC. ............... R(B) 0.12 120 -10 tetralogy of Fallot .................. R(B) 0.12 100 -10 ASD, absent right SVC. ............... R(C) 0.12 110 + 30 ASD, VSD ..................... R(B) 0.16 85 0 VSD, ASD ..................... R (B) 0.10 140 0 ASD (sinus venosus defect type), partial anomalous pulmonary venous drainage .............. R(B) 0.16 70 0 VSD ....................... R(B) 0.14 140 -15 tetralogy of Fallot .................. R (B) 0.10 150 + 10 single ventricle, transposition of great vessels, PDA, ASD . R(B) 0.22 70 -2 0 PS ........................ AVD and 0.16 100 + 40 R(C) ASD ....................... R(C) 0.12 85 + 30 tetralogy of Fallot, vascular ring, aberrant azygos vein. .. R(C) 0.12 130 140 PDA, anomalous right subclavian artcry ........ R(C) 0.14 110 + 20 tetralogy of Fallot, ASD, anomaly of lumbar vrrtebrae, cleft palate, imperforate anus ............. R(C) 0.16 85 + 30 total anomalous pulmonary venous drainage, ASD .... R(C) 0.20 120 + 70 truncus arteriosus .................. R(C) 0.12 150 + 50 PS, aberrant renal vessels ............... R(C) 0.12 95 + 30 tetralogy of Fallot .................. R(C) 0.14 60 + 30 ASD, PDA, partial anomalous pulmonary lrenous drainage R(C) 0.16 120 + 60 single atrium, VSD, PS ............... R(C) 0.12 150 + 30 tricuspid atresia, transposition of great vessels, PS .... R(C) 0.12 140 + 30 tetralogy of Fallot .................. R(C) 0.12 140 + 30 ASD (endocardia1 cushion defect type) ......... R(C) 0.16 130 $ 40 VSD ................... R(C) 0.12 100 + 50 tetralogy of Fallot .................. R(C) 0.12 120 + 50 ECG was taken during digitalis therapy. Abnormal rhythms associated with persistent left superior vena cava 213 minal negative deflection in PV, and separation of two peaks in PV,) were observed in only one of these nine, patient No. 10. Left axis of the P wave was present in two of three patients (Nos. 1, 2, and 4), in whom per- sistent left SVC draining into the coronary sinuses was associated with absent right SVC. One patient, No. 11, showed A-V dissociation that was transient, isorhyth- mic, and incomplete. The P wave showed intermediate axis (fig.3). The remaining 16 patients showed inter- mediate axis (table I, fig.2). The transverse plane P wave axes are shown in table I and are compared with the P wave axes of the other Fig.3. Electrocardiogram of a 10-year-old girl with groups in figure 4. No significant differences in trans- severe pulmonic valvular stenosis and persistent left verse plane P wave axes were noted between the group SVC draining into the coronary sinus. Note isorhyth- with persistent left SVC and the control group. P-R mic dissociation with interference (case 11). intervals were within normal limits (0.22 and 0.20 seconds), except in patients Nos. 10 and 16 (table I). There was no significant difference in average P-R intervals in patients with intermediate P wave axis, -90 - H Mean compared with those with left P wave axis.