David C. Schwartz

Ventricular septum in right ventricular volume overload: An echocardiographic study☆

Abstract This study investigated by echocardiography pre- and postoperative findings in patients with right ventricular volume overload, suggesting a mechanism for the abnormal ventricular septal motion. Twenty-one children with secundum atrial septal defect, ostium primum defect, sinus venosus defect or total anomalous pulmonary venous return were studied. Preoperatively, the expected normal posterior septal motion was reversed in 18 of the 21 patients. The mean right ventricular enddiastolic dimension index was increased in all patients and averaged 2.9 cm/m2 (range 1.9 to 3.7 cm/m2). Postoperatively, the septal motion reverted to normal in 12 patients, remained normal in 1, was reversed in 1 and became intermediate in 7. In 18 patients, the right ventricular end-diastolic dimension index was reduced, and in 3 was unchanged. The mean right ventricular end-diastolic dimension index after correction was 2.2 cm/m2. In most of the patients whose septal motion reverted to normal the right ventricular end-diastolic dimension index was reduced by 1 3 ; in patients with persistent abnormal septal motion it was reduced by less than 1 3 . Although several mechanisms may contribute to abnormal septal motion, it is most likely related to marked dilatation of the right ventricle and exaggerated anterior movement of the entire heart during systole, thus providing a net anterior motion in systole.

Plasma norepinephrine levels in infants and children with congestive heart failure

To characterize the sympathetic nervous system response to congestive heart failure (CHF) in infants and children, plasma catecholamine levels were measured in 102 subjects undergoing routine cardiac catheterization (mean age 3.3 years, range 0.1 to 14.7), including 61 with left-to-right shunts. Plasma norepinephrine levels were significantly higher (p less than 0.0001) in children with CHF than in those without CHF. A highly significant association (p less than 0.0001) was found between the level of plasma norepinephrine and severity of CHF symptoms. This relation was found for CHF secondary to lesions producing a left-to-right shunt and CHF resulting from primary myocardial dysfunction. In congenital lesions with a left-to-right shunt, plasma norepinephrine levels correlated well with size of the shunt (Qp/Qs) (r = 0.75, p less than 0.001) and degree of pulmonary arterial hypertension (r = 0.70, p less than 0.001). Elevation of plasma norepinephrine concentrations in infants and children are seen with severe CHF regardless of its origin.

Sensitivity, specificity and predictive value of two-dimensional echocardiography in detecting coronary artery aneurysms in patients with Kawasaki disease.

Seventy-seven patients with Kawasaki disease were prospectively evaluated from 1978 to 1983 to determine the sensitivity, specificity and predictive value for detecting coronary artery aneurysms with two-dimensional echocardiography. Seventy (91%) underwent selective coronary arteriography and are included in this report. The study was divided into two periods because of increased experience and the use of a systematic approach with two-dimensional echocardiography in the second period as compared with the first. Aneurysms were demonstrated in nine patients (13%). The coronary artery system was divided into six regions: proximal third of the main right coronary artery, distal right coronary artery, left main coronary artery, left anterior descending coronary artery, circumflex coronary artery and distal left coronary artery. The sensitivity and specificity were high when imaging the proximal regions, and improved from the first period to the second. Both sensitivity and specificity were lower for the more distal regions of the right and left coronary arteries. Overall, the sensitivity of two-dimensional echocardiography was 100% because there were no patients in our study who had isolated distal coronary artery aneurysms. Two-dimensional echocardiography is a sensitive and specific test for detecting aneurysms in the proximal portions of both the right and left coronary arteries, and is useful in selecting patients for invasive investigation with selective coronary arteriography.

Cardiovascular anomalies associated with tetralogy of fallot

Abstract Cardiovascular anomalies associated with tetralogy of Fallot in 161 patients are reported. Eighty-four associated anomalies were identified in 61 patients. The difficulty of clinical recognition of many of the 20 different defects is stressed. Patent foramen ovale and patent ductus arteriosus occurred frequently, especially during infancy. The common anomalies of the systemic veins and arteries included persistent left superior vena cava, aberrant left subclavian artery and congenital abnormalities of the coronary arteries. Pulmonary valvular and arterial abnormalities were common, including absence of the pulmonic valve, pulmonary artery branch stenosis and absence or hypoplasia of the left pulmonary artery. Secundum atrial septal defects were identified in 5 patients. The surgical implications of these anomalies are discussed.

Balloon atrial septostomy for left ventricular decompression in patients receiving extracorporeal membrane oxygenation for myocardial failure

We describe the use of balloon atrial septostomy to decompress the left ventricle in four patients receiving extracorporeal membrane oxygenation for acute intractable myocardial failure. These patients were becoming clinically worse and had evidence of left ventricular and left atrial hypertension either by direct measurement or echocardiography. Atrial decompression was accomplished by blade septostomy in one patient and by balloon atrial septostomy under echocardiographic guidance at the bedside in three patients. Three of four patients improved after balloon atrial septostomy and survived. This procedure may be helpful in selected patients receiving extracorporeal membrane oxygenation for myocardial failure with evidence of increased left atrial pressure as a result of increased ventricular pressure.

Systemic hypertension secondary to peripheral vascular anomalies in patients with Williams syndrome.

ng/ml , n = 20). Although whole blood serotonin concentrations may decrease with increasing age, 1~ values in patient 1 were also elevated compared with those in an age-matched normal pediatric population we are studying (values to be reported elsewhere). Elevated serotonin levels in children with Williams syndrome adds to the growing list of disorders that have evidence of central nervous system serotonergic dysfunction? In summary, medical, developmental, and psychologic data have been described in two children with Williams syndrome and autism. The documentation and comparison of specific abnormalities in autistic Children with different associated organic conditions may help to delineate the neurobiologic cause of both the behavioral phenotype and the underlying genetic conditions.

Effect of digoxin on contractility and symptoms in infants with a large ventricular septal defect

The effect of digoxin on contractility and symptoms in infants with a large ventricular septal defect (VSD) is controversial. Nineteen infants with symptoms of congestive heart failure due to a VSD were studied with load-independent indexes during 4 study periods: (1) before any medication; (2) while on chronic diuretics; (3) while on both diuretics and digoxin; and (4) while on diuretics alone, to determine if digoxin: (a) increases contractility when added to diuretic therapy; and (b) improves symptoms. Symptoms, signs (heart and respiratory rates, and weight gain), shortening fraction, preload (left ventricular end-diastolic dimension), afterload (left ventricular end-systolic wall stress) and contractility were measured at each period. The difference between the measured and predicted velocities of circumferential fiber shortening for the measured left ventricular end-systolic wall stress served as an index of contractility. Eighteen infants also underwent catheterization. Mean pulmonary-to-systemic blood flow ratio was 3:1. When digoxin was added to diuretics, contractility index was significantly greater than in control subjects (0.13 +/- 0.15 vs 0.0 +/- 0.12 circ/s, p = 0.04). When patients were again on diuretics alone (after discontinuation of digoxin), contractility index was no longer different. Symptoms and signs were not significantly improved by either diuretics or digoxin. It is concluded that in infants with a large left-to-right VSD shunt and receiving digoxin and diuretics, contractility index was significantly greater than in control subjects. However, neither diuretics alone nor in combination with digoxin improved symptoms significantly.

Late Results of Reconstruction of the Right Ventricular Outflow Tract with Porcine Xenografts in Children

Thirty-three children, aged 2.5 to 17.5 years (mean, 8.3 years), having xenograft external conduits placed between the right ventricle and pulmonary artery were followed for 1 to 6 years postoperatively (mean, 3.5 years). There were no late deaths in the study group, and no infection of a valved conduit has been demonstrated. Twenty of these children were catheterized during the follow-up period. The gradients from the right ventricle to pulmonary artery ranged from 8 to 90 mm Hg (average, 31 mm Hg). A total of 8 patients were classified as having hemodynamically documented conduit failure, and an additional 2 patients are clinically expected to have conduit failure. This represents a total incidence of 30% xenograft conduit failure in a 6-year follow-up. Although the etiology of this dysfunction is probably multifactorial, factors such as valve size, conduit angulation, and immunological competence bear special consideration. We conclude that although valved external conduits continue to play an important role in the treatment of complex congenital heart disease, a valved conduit with greater longevity is needed for use in children.

Changes in cardiac function during extracorporeal membrane oxygenation for persistent pulmonary hypertension in the newborn infant

The effects of extracorporeal membrane oxygenation (ECMO) on cardiac function and its determinants (preload, afterload, contractility, and heart rate) are largely unknown, although some evidence exists that function may decrease. To determine whether cardiac function decreases and what changes in the determinants take place during and after ECMO, we observed 26 newborn infants with persistent pulmonary hypertension. Serial echocardiograms were performed before ECMO, during maximum cardiopulmonary bypass, and after ECMO. Cardiac function was assessed by using standard echographic ejection phase indices (shortening fraction and cardiac output). Heart rate, preload (left ventricular end-diastolic dimension and area), afterload (left ventricular end-systolic wall stress), and contractility (relationship between velocity of circumferential fiber shortening and wall stress) were also measured. Ejection phase indices significantly decreased during ECMO (shortening fraction 33% to 25%, cardiac output 205 to 113 ml/kg/min; p less than 0.05) and returned to normal after ECMO (shortening fraction 26% to 34%, cardiac output 107 to 240 ml/kg/per minute; p less than 0.05). Heart rate also significantly decreased during ECMO (158 to 118 beats/min; p less than 0.05). Preload significantly increased after ECMO (left ventricular end-diastolic dimension 1.4 to 1.6 cm, left ventricular end-diastolic area 1.9 to 2.2 cm2; p less than 0.05). There were no significant changes in contractility and afterload during any study period. We conclude that, although left ventricular ejection phase indices and heart rate decreased during ECMO, these changes were transient and resolved when bypass was terminated. Contractility and afterload did not appear affected by bypass.

Relation of symptoms to contractility and defect size in infants with ventricular septal defect

Forty-two infants with a ventricular septal defect (VSD) (21 asymptomatic and 21 symptomatic) were compared with 17 control infants to determine if symptoms of congestive heart failure (i.e., tachypnea/poor growth) were due to depressed contractility or defect size, or both. Echocardiographic indexes of defect size, left ventricular performance (shortening fraction), preload (left ventricular end-diastolic dimension), afterload (left ventricular end-systolic wall stress) and contractility (the relation between velocity of circumferential fiber shortening and wall stress) were measured. Clinical assessment included measurement of weight and respiratory rate. Pulmonary and systemic blood flow were assessed in 17 symptomatic and 3 asymptomatic patients by cardiac catheterization. Although there was no significant difference in age, the symptomatic group had significantly lower weight (5.5 +/- 2.9 vs 7.3 +/- 2.3 kg, p less than 0.05) and a higher respiratory rate (53 +/- 14 vs 43 +/- 6 breaths/min, p less than 0.05), compared with control subjects. The mean pulmonary to systemic blood flow ratio in the symptomatic group was 2.9:1. Preload indexed for body surface area was significantly higher in the groups with a VSD compared with control subjects (asymptomatic, 8.5 +/- 1.7 cm/m2; symptomatic, 9.1 +/- 1.7 cm/m2; control subjects, 6.8 +/- 1.1 cm/m2; p less than 0.05). Shortening fraction, afterload and contractility were not significantly different among all groups. A defect size greater than 0.5 cm (or defect size indexed for body surface area greater than 1.8 cm/m2) was predictive of the presence of symptoms. It is concluded that contractility is normal in infants with a VSD. Symptoms may be related to pulmonary congestion.(ABSTRACT TRUNCATED AT 250 WORDS)