Congenital bilateral subclavian steal: ductus-dependent symptoms in interrupted aortic arch associated with ventricular septal defect.

There are two types of congenital bilateral subclavian steal. The first type is accompanied by severe coarctation or interruption of the aorta in which both the right and left subclavian arteries have their origin distal to the obstruction in the aorta. In most cases with complete interruption of the aorta there is a large ventricular septal defect. The second, less common type of steal is associated with isolated atresia of the proximal segment of the subclavian arteries. In the first type of steal, the anatomic predisposition for the steal is present from birth but clinical symptoms frequently do not appear until childhood or adolescence. In the newborn the presence of a widely patent duclus arteriosus and its capacity to transmit the flow and pressure from a hypertensive pulmonary artery to the descending aorta and thus to the subclavian arteries prevents cerebral symptoms and angiographic signs, but in the older infant and child, the internal diameter of the ductus has usually decreased, leading to symptoms of the subclavian steal syndrome.

Electrophysiologic cardiac function before and after surgery in children with atrioventricular canal.

Thirty-two children with atrioventricular (AV) canal underwent electrophysiologic studies: 18 underwent preoperative studies at a median age of 3 years (range 6 months to 16 years); 14 underwent postoperative studies at a median age of 4 years (range 2 to 19); and 2 underwent both preoperative and postoperative matched studies. In the preoperative group the following abnormalities were observed: first-degree AV block in 5 patients (due to internodal conduction delay in 1, AV nodal conduction delay in 2 and normal intracardiac intervals in 2); internodal conduction delay but normal PR interval in 4; and disease of the sinus node in only 1. In the postoperative group the following abnormalities were observed: first-degree AV block in 9 (due to AV nodal conduction delay in 2, His-Purkinje system conduction delay in 1, upper normal intracardiac intervals in 3 and unidentified in 3); prolongation of the right ventricular apical activation time in 11 of 13 with right bundle branch block; abnormal sinus node function in 3; and abnormal AV nodal function in 4 (1 of whom had associated sinus node disease). Atrial and ventricular functions were normal in all preoperative and postoperative patients. Electrophysiologic dysfunction is rare in preoperative patients with AV canal; in postoperative patients electrophysiologic abnormalities occur in 38% and involve the sinus and AV nodes in 19 and 25%, respectively.

Site of conduction delay and electrophysiologic significance of first-degree atrioventricular block in children with heart disease.

Associated electrophysiologic abnormalities and site of delay were studied in 20 patients, aged 1.5 to 16.5 years, with congenital heart disease and first-degree atrioventricular (AV) block (PR interval above the 98th percentile for age and heart rate). Eight of the 20 patients with first-degree AV block were studied after 1 or more cardiovascular operations. Refractory periods of the atrium, AV node, His-Purkinje system and ventricle were determined. As a further test for AV nodal integrity, rapid atrial pacing was performed and the cycle at which Wenckebach periodicity occurred was noted. Four groups were identified. Group I included 4 patients (20%) with intraatrial conduction delay (long PA interval). Three patients had depressed sinus nodal function and 1 had depressed AV nodal function. Group II included 7 patients (35%) with AV nodal delay (long AH interval). One patient had sinus nodal depression and 2 had AV nodal depression (prolonged AV nodal refractory period or Wenckebach at a long paced cycle length). Group III included 3 patients (15%) with His-Purkinje delay (long HV interval). Measured functions were normal in all patients. Group IV included 6 patients (30%) with normal or high normal intracardiac intervals with long PR. One patient had sinus nodal dysfunction, 2 patients had long atrial refractory periods, 1 had AV nodal depression; 2 had long refractory period of the His-Purkinje system, and 1 had long ventricular refractory period. Atrial flutter was induced in 1 patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Dual atrioventricular nodal pathways: a benign finding in arrhythmia-free children with heart disease.

The incidence and significance of dual atrioventricular (A-V) nodal pathways are described in 78 children with associated congenital or acquired heart disease. None of these patients had clinical or electrocardiographic evidence of arrhythmia. Dual A-V nodal pathways were observed in 35 percent of the preoperative group and in 33 percent of the postoperative group. Despite this substrate for A-V nodal reentry, supraventricular tachycardia was neither induced during electrophysiologic evaluation nor did it develop clinically over a follow-up period of 1 month to 15 years. It is concluded that dual A-V nodal pathways are common and may be a benign finding in arrhythmia-free children with heart disease.

The fast-slow form of atrioventricular nodal reentrant tachycardia in children.

An unusual form of atrioventricular (A-V) nodal reentry is described as the underlying mechanism for incessant tachycardia in two children. During tachycardia a fast pathway was utilized for anterograde conduction and a slow pathway for retrograde conduction. This is the reverse of the usual form of A-V nodal reentrant tachycardia, in which the slow pathway is utilized for anterograde conduction and the fast pathway for retrograde conduction. One patient had a smooth ventriculoatrial (V-A) conduction curve demonstrating exclusive utilization of the slow pathway for retrograde conduction. The other had a discontinuous V-A conduction curve demonstrating failure of retrograde fast pathway conduction with resultant slow pathway conduction. In both cases the retrograde effective refractory period of the fast pathway was longer than that of the slow pathway, resulting in the establishment of this unusual reentry circuit. Both patients had a superior P axis with a P-R interval shorter than the R-P interval during tachycardia, features described in a significant number of children with incessant tachycardia. This unusual form of reentrant tachycardia can be suggested by its electrocardiographic pattern and is another mechanism for reentrant tachycardia not previously documented in children.

Left isomerism and complete atrioventricular block: a report of six cases.

Six children, aged 12 days to 13 years, with left isomerism and complete atrioventricular (A-V) block are presented. In all six patients the diagnosis of left isomerism was suggested by an interrupted inferior vena cava found during cardiac catheterization and angiocardiography; four patients had complex heart disease consisting of endocardial cushion defect, five had a common atrium, three had pulmonary stenosis, three had patient ductus arteriosus and two had dextrocardia. Further anatomic abnormalities included situs inversus of the viscera (four patients) as well as partial malrotation of the bowel. Of the six patients, four had congenital complete A-V block, whereas the remaining two had A-V conduction disturbances documented during early infancy that progressed to complete A-V block later in life. All six patients required pacemaker implantation and five of the six patients died. This report discusses the clinical presentation of complete AV block and left isomerism and reviews the literature.

Congenital systemic arteriovenous fistula between the descending aorta, azygos vein, and superior vena cava.

Various congenital systemic arteriovenous fistulas have been described. An unusual case of congenital systemic arteriovenous fistula arising from the descending aorta and draining separately into the superior vena cava, the azygos vein, and the innominate vein is reported. Clinically, this case simulated a patent ductus arteriosus. To our knowledge, this particular anomaly has not been described before.

Single coronary artery originating from the right pulmonary artery.

An infant with a single coronary artery originating from the right pulmonary artery branch is the subject of this report. He survived to the age of one month possibly because of the association of two ventricular septal defects. While the pulmonary vascular resistance remained high, perfusion of the heart muscle was accomplished due to the pulmonary hypertension. The electrocardiogram did not show typical signs of infarction, but poor left ventricular contractility was observed by echocardiogram. The diagnosis was made postmortem. This specific coronary malformation has not been previously described and needs to be included in the classification of congenital coronary arteries anomalies.

Anomalous origin of the left anterior descending coronary artery from the pulmonary artery.

Three children were identified as having anomalous origin of the left anterior descending coronary artery (LAD) from the pulmonary artery (PA). Two had had congestive heart failure in infancy with clinical diagnosis of endocardial fibroelastosis and all had abnormal ECGs. The correct diagnosis was delayed in each case, and two patients required selective coronary angiography. Surgery was accomplished in the three children although ECG abnormalities have persisted and one child has dyskinesis of the left ventricular apex. Because this diagnosis may be difficult to make when intercoronary anastomoses are inadequate to outline the left anterior descending coronary flow into the PA, patients with clinical findings suggestive of anomalous coronary artery may require selective coronary studies to exclude this anomaly.

Atrioventricular reciprocal rhythm and chronic reciprocating tachycardia in a newborn infant with concealed Wolff-Parkinson-White syndrome.

A case of atrioventricular reciprocal rhythm and chronic reciprocating tachycardia in a newborn infant is presented. Electrophysiological studies suggest that these rhythm disturbances are related to the presence of a right-sided atrioventricular accessory pathway capable only of retrograde conduction (concealed Wolff-Parkinson-White syndrome). The technique of recording the sequence of atrial activation during the tachycardia is described and its clinical importance emphasised.

Exposure of concealed right bundle branch block in Wolff-Parkinson-White type B by pacing from the vicinity of the A-V node.

In two infants with Wolff-Parkinson-White type B, right bundle branch block was concealed during sinus rhythm and pacing from close to the atrial entrance of the right-sided accessory pathway. However, pacing from the vicinity of the A-V node, the A-V node itself, and the His bundle exposed the right bundle branch block by producing exclusive ventricular activation through the normal, A-V nodal His-Purkinje pathway. In addition, pacing from close to the A-V node also resulted in fusion beats characterized by absence of delta waves with (pseudo) normal QRS complexes and short H-V intervals. False patterns of tachycardia-dependent and bradycardia-dependent block in the accessory pathway also occurred. These dynamic phenomena were attributed to the (peri-A-V nodal) pacing-related, relatively early arrival of excitation at the ventricles through the normal pathways coexisting with delayed arrival of excitation via the accessory pathway. The latter in turn was due to the longer intra-atrial conduction time from paced (peri-A-V nodal) site to atrial entrance of the accessory pathway.

Arrival of excitation at the left ventricular apical endocardium in Wolff-Parkinson-White syndrome type B.

Electrograms were recorded from the His bundle area, right ventricular apex, right ventricular inflow tract, and left ventricular apical endocardium in four patients (aged, 1, 1, 1.5, and 16 years) with Wolff-Parkinson-White syndrome type B. In beats without preexcitation: (a) delayed activation of the right ventricular inflow tract reflected the occurrence of a conduction disturbance through the "distal" or "peripheral" ramifications of the right bundle branch; and (b) the slightly earlier activation of the left ventricular apical endocardium (in reference to the right ventricular apex) may have been due to an earlier emergence from the divisions of the left bundle branch, presumably due to the greater length of the right bundle branch. In beats with preexcitation: (a) the "incomplete" right bundle branch block pattern was concealed because the right ventricular inflow tract was activated before the right ventricular apex; (b) the delta-right ventricular apical intervals were shorter than those of adults with Wolff-Parkinson-White type B; and (c) arrival of excitation at the left ventricular endocardium was a function, either of the impulse emerging from the left bundle branch, or of that propagating from the preexcited site. Therefore, the delta-left ventricular apical endocardial intervals were considered to have represented conduction time from preexcited region to endocardium of left ventricle only when it could be proven that the conduction time (from atrial site of origin to left ventricular apical endocardium) was shorter through the right sided accessory pathway than through the normal pathway. This study suggests that some beats, which may be interpreted as representing "pure" Wolff-Parkinson-White type B complexes from epicardial maps, may in reality be "fusion" complexes.

A method of maintaining thermal homeostasis during cardiac catheterization in newborns.

This device has been designed to maintain thermal homeostasis in newborns undergoing cardiac catheterization. It is easily constructed from materials available in any hospital, and it is safe and effective. It consists of a warming coil and a delivery unit made from Plexiglas which encloses the patient. In addition to maintaining a neutral thermal environment, it allows for the selection of any desired oxygen concentration by simply blending the gas mixture before warming and delivery. Since using this device we have had no problems or complications related to thermal stress during catheterization of the neonate.

Takayasu's arteritis associated with glomerulonephritis. A case report.

Takayasu's disease is a nonspecific arteritis of unknown cause with predilection for the aortic arch and its branches; approximately 20% of those affected are children or adolescents, predominantly females. The purpose of this article is to report the case of a young girl in which the mode of presentation was microscopic hematuria and proteinuria. Subsequently, aortic valvular insufficiency developed and there was evidence of aortitis in the thoracic and abdominal aorta, as well as in the arch. All functional and anatomical cardiac derangements were documented by ultrasound and angiocardiography. Renal biopsies showed progressive glomerular involvement characterized by focal and segmental glomerulonephritis. It is postulated that a common immunologic mechanism was responsible for the aortic and glomerular lesions.

Analysis of surgically-induced right bundle branch block pattern using intracardiac recording techniques.

Using intracardiac recording techniques, His bundle (H) and right ventricular apical (RVA) electrograms were recorded in 16 patients with a postoperative electrocardiographic pattern of right bundle branch block (RBBB). Their ages ranged from 5 to 12 years (mean 6.9 years) at surgery and the follow-up period was 1 to 7 years (mean 2.7 years). All were asymptomatic and in sinus rhythm at the time of study. The P-A interval was normal in all and the A-H, H-V, and V-RVA intervals were prolonged in one, one, and six patients, respectively. The V-RNA interval was normal (less than or equal to 30 msec) in ten out of the 11 patients (91%) without associated left anterior hemiblock (LAH), indicating a physiologically intact main right bundle branch, and was abnormally lengthened (45-62 msec) in all five patients (100%) with associated LAH. These findings suggest that there are two subgroups of patients with surgicall-induced RBBB pattern and the measurement of the V-RVA interval in conjunction with the H-V interval may be of ultimate importance in understanding the long-term prognostic implication of surgically-induced RBBB pattern with or without LAH.

Determinants of ventricular refractory periods in children with congenital heart disease: effects of cycle length and age.

Ventricular effective refractory periods (ERP) and functional refractory periods (FRP) were determined by programmed ventricular extrastimulation in 53 pediatric patients with a spectrum of congenital heart disorders. Of these 63 children (ages 8 months to 18 years), 38 were preoperative, 17 had repair of their cardiac lesion via right ventriculotomy, and eight were postoperative without a ventriculotomy. We demonstrated that there was a linear relationship between the cycle length and ventricular refractory periods. The regression equations 73 + 0.29 x cycle length (msec) for the ventricular ERP (msec) and 80 + 0.30 x cycle length (msec) for ventricular FRP (msec) were found to define the determined properties of ventricular refractory periods (VRP) in children. These VRP characteristics were independent of age in children less than 13 years of age.

M-mode echocardiographic findings in children with idiopathic restrictive cardiomyopathy.

The M-mode echocardiographic findings in five pediatric patients, ages 4-15 years, with primary idiopathic restrictive cardiomyopathy, diagnosed by cardiac catheterization, and of 12 normal children (control group) are presented. The M-mode echocardiographic findings in patients with restrictive cardiomyopathy were (1) normal left and right ventricular end-diastolic dimension, (2) normal left ventricular posterior wall and interventricular septal thickness (three patients) or mild concentric hypertrophy (two patients), (3) normal opening and closing velocity of the mitral valve, (4) consistently enlarged left atrium (more than 40 mm) in all, and (5) right ventricular systolic time intervals compatible with pulmonary artery hypertension. The left ventricular ejection phase parameters (systolic time intervals, shortening fraction, and mean velocity of circumferential fiber shortening) were normal. Left ventricular relaxation phase parameters (diastolic function) were abnormal. The isovolumic relaxation time index was prolonged, 68 +/- 40 ms (+/- SD), in the study group as compared with 11 +/- 6 ms (+/- SD) in the control group (P less than 0.001). Percent relaxation of left ventricular posterior wall endocardium at 50% of diastole was decreased, 58 +/- 4% (+/- SD), in the study group as compared with 85 +/- 6% (+/- SD) in the control group (P less than 0.005). We conclude that M-mode echocardiography provides a relatively useful and specific noninvasive method for the diagnosis of primary restrictive cardiomyopathy in pediatric patients.

Echocardiographic assessment of right bundle branch injury after repair of tetralogy of Fallot.

Nineteen patients, ages 3 1/2-18 years, with electrocardiographic evidence of right bundle branch injury after intracardiac repair of tetralogy of Fallot, underwent invasive intracardiac electrophysiologic evaluation 1-13 years (mean 4.4 years) postoperatively. Categorization of the site of right bundle branch injury as proximal or distal was made by determining the V-RVA interval. In 11 of the patients, the V RVA interval was prolonged (> 35 msec), indicating proximal right bundle branch injury and in the other eight it was normal (< 35 msec), indicating distal bundle branch injury. Within 24 hours of the study, all patients were studied by M-mode echocardiography. Measurements were made of the tricuspid valve closure, mitral valve closure and the difference between the two, or the delta value. All but one patient with distal bundle branch injury had delta values of less than 40 msec (range 8-38 msec), while 10 or 11 patients with proximal bundle branch injury had delta values greater than 40 msec (range 41-116 msec). there was a significant positive correlation (r = 0.74, p < 0.001) between V-RVA and the delta value. We conclude that the delta value is an indicator of relative activation delay of the right ventricle, and therefore, in most cases, proximal vs distal bundle branch injury can be diagnosed noninvasively.