David W. Sapire

Complete Heart Block and Fatal Right Ventricular Failure in an Infant

### Drs David W. Sapire and Suzanne M. Lopez #### Maternal History The mother of this child was a 22-year-old primigravida in apparent good health. There was no clinical or biochemical evidence indicating use of ethanol, addictive drugs, or other possibly teratogenic substances. Fetal heart rate on ultrasonograms done early in her pregnancy was about 150 beats per minute. Near the end of her fifth month of pregnancy, she was referred to the John Sealy Hospital at the University of Texas Medical Branch (UTMB) because the fetal heart rate had decreased to 86 beats per minute. Although the atrial rate on subsequent examinations remained about 150 beats per minute, the ventricular rate ranged from 40 to 50 beats per minute. Two weeks before delivery, atrial and ventricular rates were 144 and 47 beats per minute, respectively. When the ventricular rate began to slow even further, it was decided that risk of intrauterine death was imminent, and a Caesarean section delivery was performed at approximately the 28th week of gestation. There was no significant family history relevant to the case. The mother’s serological studies for lupus erythematosus and antiphospholipid syndrome were negative. #### Infant’s Hospital Course The baby was in no major distress just after delivery, but her heart rate increased very little in response to increasing doses of isoproterenol. Within hours after birth, it was decided that an electronic pacemaker was advisable. During epicardial placement of electrodes near the left ventricular apex, the surgeon noted that the “infiltrated” right ventricular myocardium was thin and that it did not respond to electronic pacing. Over the following weeks, there were no conducted atrial beats, although there were regular P waves. Occasional single and multiple ventricular premature beats were recorded, but the heart was driven primarily by the electronic pacemaker. The main clinical problem was increasing right ventricular failure that did not respond to intensive care in the high-risk …

Diagnosis and significance of atrial isomerism

Fifty-one patients at the Brompton Hospital were identified as having either right or left atrial isomerism by reviewing the records and catheterization, echocardiographic and, in 17 cases, autopsy data. Every study patient had 1 or more of the following conditions: isomeric bronchial anatomy; angiographic or necropsy evidence of atrial anatomy; echocardiographic diagnosis of isomerism; and anomalies of systemic or pulmonary venous connection. Patients with anomalous venous connections all had additional signs of isomerism. Neither right nor left type was predominant in either sex. The heart was in the left chest slightly more often than the right. Abdominal visceral heterotaxy was the most frequent radiographic finding. An ambiguous and biventricular connection was the commonest type of atrioventricular (AV) connection in left isomerism. A common AV valve was the most frequent mode of connection in both forms. Univentricular AV connection, double-outlet right ventricle, pulmonary atresia and discordant ventriculoarterial connection were commoner in right isomerism. Left isomerism is associated with much longer survival, its constellation of associated malformations frequently being less severe and more amenable to corrective surgery. A precise diagnosis must be made during life in order to select the most appropriate treatment.

Atrial septal aneurysms in infants and children

Interatrial septal aneurysm (IASA) has been detected with increasing frequency since the advent of two-dimensional echocardiography (2DE). In this study, we investigated the prevalence, characteristics, and predisposing factors in IASA formation in 724 infants, children, and adolescents undergoing 2DE. Among this group, 12 patients had an IASA (prevalence = 1.7%). Eleven of the 12 patients had abnormal atrial hemodynamics as a result of either structural heart disease or significant supraventricular dysrhythmias. Follow-up 2DE performed in 10 of 12 patients, 1 to 48 months (mean 16.5 months) after the initial diagnosis, demonstrated diminution or resolution of the IASAs in those patients who had normal hemodynamics following surgical or spontaneous closure of their intracardiac defect, or medical control of their dysrhythmias. In contrast, IASAs became more prominent in those patients with persistent hemodynamic abnormalities. The high prevalence rate and subsequent involution of many IASAs in infants suggest that in the presence of abnormal atrial hemodynamics, the neonatal atrial septum may be prone to aneurysm formation because of inherent structural weaknesses of the neonatal septal tissue. In the absence of continued hemodynamic stress., the majority of these IASAs in infants resolve with maturational changes in the septum and normal cardiac growth.

Subclavian-artery-to-innominate-vein fistula presenting with congestive failure in a newborn infant

SummaryCongestive heart failure associated with intrathoracic arterio-venous fistula has not, to our knowledge, been reported previously in a newborn infant. A 2×4 mm arterio-venous fistula between the subclavian artery and innominate vein presented on the first day of life with heart failure and required surgical intervention. The uncommon location of the fistula produced potentially misleading radiologic findings.When the infant was 2 days old the fistula and a 12 mm diameter persistent ductus arteriosus were ligated; following this, heart failure regressed.

Deletions in Chromosome 22q11 Region in Cervical Aortic Arch

Two patients with cervical aortic arch are described, both with deletions in chromosome 22q11 region, and thymic hypofunction. This suggests that cervical aortic arch is part of the spectrum of the CATCH 22 group of defects.

True congenital aneurysm of the septum primum not associated with obstructive right- or left-sided lesions: Identified by two-dimensional echocardiography and angiography in a newborn

SummaryAneurysms of the interatrial septum are unusual anomalies that have been demonstrated by (M-mode and 2-dimensional) echocardiography in patients with complex congenital heart defects. They have also been found at autopsy in adults without heart defects. Complications have resulted from these aneurysms in adults. A true aneurysm of the septum primum was an incidental finding identified by 2-dimensional echocardiography and angiography in a newborn with an atrial septal defect.

Decorticate posture following ‘cardiac cocktail’

SummaryTwo children undergoing cardiac catheterization became irritable 1–3 hours after IM premedication that included phenothiazines. IV diazepam was administered and their irritability subsided. Within another 30 minutes they developed a decorticate posture from which they recovered shortly after IV diphenhydramine hydrochloride. The decorticate posture is believed to be an idiosyncratic reaction to phenothiazines. IV diphenhydramine may be preferable to diazepam when irritability develops following premedications that include phenothiazines.

Absent right atrioventricular connexion with the left atrium connected to the morphologically right ventricle, a right-sided rudimentary left ventricle, and right juxtaposition of the atrial appendages: documentation by angiography and cross-sectional echocardiography

In this report, a 12-hr-old male infant was demonstrated to have the absent connexion variant of right atrioventricular valve atresia with the left atrium connected to the morphologically right ventricle with a right-sided rudimentary left ventricle. The aorta arose from the right ventricle and there was pulmonary atresia, the pulmonary circulation being duct-dependent. In addition there was right juxtaposition of the atrial appendages. The definitive cross-sectional echocardiographic and angiographic findings are presented.

Capsular stroke in congenital complete heart block.

A normally developed 6 year old boy with congenital complete heart block presented with right hemiparesis of one month duration. The ventricular pacemaker which was implanted at two months of age had not been functioning for four years and was not replaced because there was no history of syncope, dizziness, or decreasing exercise tolerance even though the ventricular rate was 54 beats per minute. Computerized tomography revealed an infarct in the left internal capsule. Stokes-Adams attacks have been reported as a complication in children with congenital heart block but cerebrovascular accidents as in this patient are unusual (1, 5, 6, 9).

T-Cell and Parathyroid Dysfunction in Conotruncal Cardiac Defects: Relationship to 22q11 deletion. • 121

Recent observations of deletion in chromosome 22q11 in patients with conotruncal heart defects (CHD) has led to suggestions that these patients belong to the CATCH 22 group of defects. Subtle abnormalities of T-cell numbers and low levels of parathormone (PTH) are frequently seen in patients with CHD. The details of the relationship of T-cell and parathyroid dysfunction, occurring in patients with CHD, to 22q11 deletion is not fully established. We studied 34 patients with CHD. The surface markers of peripheral lymphocytes were identified by flow cytometry and CD3, CD4, CD8, CD16, and CD19 positive cells were counted. PTH was measured by radioimmunoassay. Fluorescent in situ hybridization using probe D22S75 was performed on the metaphase chromosome spreads. As this probe may not detect a smaller deletion in 22q11, genotyping of the patient and parents (where available) were done using 5 microsatellites to probe for smaller deletions involving these loci. Four microsatellites mapped to the DiGeorge critical region on 22q11 (D22S941, D22S944, D22S311, D22S264), and 1 mapped to the 10p region, deletion of which is also associated with DiGeorge syndrome (D10S585). Eight patients had deletions in 22q11 based on D22S75. One other patient had a deletion involving the locus D22S944, but not D22S311 or D22S264. No patient had a deletion in the 10p region. The number of patients in the categories of CD3 count 15% (CD3+ cells which are both CD4- and CD8-, normal <10%) and low PTH (<10pg/ml) are as follows:Table In conclusion, reduction in T-cell numbers and PTH levels occur frequently in patients with CHD, irrespective of a detectable deletion in 22q11, consistent with the notion of overlap between patients with CHD and CATCH 22. Some of these patients may have a smaller deletion in 22q11, as demonstrated in one of our patients, or even a point mutation in one of the critical genes. High numbers of double negative T-cells have not been described in CATCH 22 previously, and may further indicate disordered T-cell differentiation.