Robert Solinger

Echocardiography in the Normal Neonate

Utilizing the atrioventricular and semilunar valves as ultrasonic landmarks, a simple reproducible technic is described for the ultrasonic evaluation of the heart and its great vessels in the normal neonate. The importance of the clinical application of this method is discussed.Echocardiographic studies were performed on 240 normal newborns. Qualitative assessment was made of the interrelationships of the pulmonary, aortic, tricuspid, and mitral valves, and of interventricular septal motion. Quantitative norms were obtained for the following parameters: amplitude of motion of anterior leaflets of tricuspid and mitral valves, anteroposterior diameter of the ventricular and left atrial cavities, thickness of ventricular walls and interventricular septum, outside diameter of aortic and pulmonary roots, and interaortic and interpulmonary cusp distances.

Transtelephonic echocardiography: Successful use in a tertiary pediatric referral center

Recent advances in computers and telecommunications have made transtelephonic echocardiography practical. Our institution is developing a network of transmissional echocardiographic sites at several hospitals in our referral region. We reviewed our initial experience to determine whether transmissional echocardiographic studies (1) gave an appropriate diagnostic impression compared with subsequent videotape review and (2) led to appropriate clinical management (i.e., transfer to a tertiary center or continuation of local care and follow-up). From Aug. 1, 1991, to May 31, 1992, we evaluated 47 transmissional studies (diagnoses: 24 normal, 8 patent ductus arteriosus, 6 ventricular septal defect, 2 pulmonary stenosis, 1 ventricular septal defect with interrupted aortic arch, and 6 miscellaneous). Of 47 studies, 39 (83%) were thought to give accurate diagnostic impressions compared with videotape review. Most inaccuracies were due to the selection and transmission of inconclusive information in an otherwise accurate diagnostic study. Only 1 (2%) of 47 studies resulted in an inappropriate clinical decision; a patients transfer for treatment of a potent ductus arteriosus was delayed 1 day because of an inconclusive transmissional study. We conclude that transmissional echocardiography is useful in the management of pediatric patients with suspected heart disease in a regional referral setting.

Echocardiographic evidence of outflow tract obstruction in Pompe's disease (glycogen storage disease of the heart)

A 7 month old black female infant with the clinical findings of Pompes disease is presented. The diagnosis of an infiltrative myocardiopathy with left ventricular outflow tract obstruction presenting with a pronounced systolic anterior motion of the anterior mitral valve leaflet was made by echocardiography. This diagnosis was confirmed by cardiac catheterization and angiocardiography. Pathologic findings were consistent with Pompes disease (type II glycogen storage disease). The presence of systolic anterior motion of the mitral valve in this patient suggests that this finding is not pathognomonic of idiopathic hypertrophic subaortic stenosis.

Deductive Echocardiographic Analysis in Infants with Congenital Heart Disease

A step-by-step approach to cardiac diagnosis utilizing a chest X-ray and echocardiography is described and used to study a normal infant and six infant patients with angiocardiographically-proven complex congenital heart malformations.The heart is divided into three major anatomical segments in order to localize the atrial and ventricular chambers and determine the relationship of the great arteries. The atrial chambers are localized by noting the position of the liver on the X-ray. The right atrium is on the same side as the liver with few exceptions. The ventricular chambers are localized by echocardiographically identifying the tricuspid and mitral valves. They are a part of the morphologically right and left ventricles, respectively. As a general rule, the atrioventricular valve whose anterior leaflet is continuous with the posterior margin of a semilunar valve is the mitral valve. The atrioventricular valve whose anterior leaflet is not continuous with a posterior semilunar valve margin is the tricuspid valve. When the tricuspid valve is to the right of the mitral valve, the ventricles are in their normal positions (ventricular d-loop); when it is to the left, the ventricles are inverted (ventricular l-loop). The relationship of the great arteries is determined by echocardiographically identifying the semilunar valves and noting their positions relative to each other, the interventricular septum and the ventricular chambers. In a ventricular d-loop, the aortic valve is usually to the right of the pulmonary valve. In a ventricular l-loop, the opposite is true. As much as a 17% error may exist when transposition of the great arteries is a component of the malformation. Therefore, as additional aids in semilunar valve identification the R-C intervals of the valves (interval between R wave of electrocardiogram and valve closure on echogram) and outside diameters of the valve roots are measured. Usually the R-C interval is longer and, in the absence of pulmonary stenosis, the outside diameter greater for the pulmonary valve. The segmental diagnoses are then combined to obtain the “type’ of heart, and a careful search is made for associated defects.Using this approach, the positions of the atrial and ventricular chambers and the relationship of the great arteries were accurately determined in the six complex cardiac malformations studied.

Natriuretic Peptides in Cardiovascular Diseases of Fetus, Infants and Children

The natriuretic peptides (NP) appear to be functional by midgestation, respond to volume stimuli, and regulate blood pressure and salt and water balance in the developing embryo. In addition, the NP may help regulate the blood supply to the fetus, acting as vasodilators in the placental vasculature. Peaks of ANP and BNP expression during gestation coincide with significant events in cardiac organogenesis, suggesting a role for NP in the formation of the heart. Levels of atrial natriuretic peptide (ANP) are higher in the fetal circulation than in adults, and fetal ventricles express higher levels of ANP and B-type natriuretic peptide (BNP) than adult ventricles. In this comprehensive review we have discussed the role NP during development of the fetal heart and circulation and in various cardiovascular diseases of neonatal and pediatric age group.

Townes Syndrome A Distinct Multiple Malformation Syndrome Resembling VACTERL Association

An 8-year-old male is presented with clinical findings of Townes syndrome in an otherwise unaffected family. Additional abnormalities possibly representing low frequency associations of this autosomal dominant multiple malformation syndrome included a cardiac defect and hypospadias. Similarities exist between Townes syndrome and VACTERL association, which is generally regarded to be sporadic in nature. Recognition of Townes syndrome as a distinct entity is critical for implementing appropriate management in early childhood, including amplification of hearing impairments. Variable expressivity may occur in this disorder. Careful evaluation must be made, therefore, of the parents of an affected infant with an apparent sporadic case, in order to provide the couple with an accurate recurrence risk at genetic counseling.

Role of Natriuretic Peptide Family in Cardiovascular Medicine

The natriuretic peptides (NP) are a group of structurally similar but genetically distinct peptides with many favorable physiological properties that have emerged as important candidates for development of diagnostic tools and therapeutic agents in cardiovascular diseases. The NP family includes atrial natriuretic peptide (ANP, 28AA), urodilatin (INN: Ularitide, 32 AA), B-type natriuretic peptide (BNP, 32AA), C-type natriuretic peptide (CNP, 22AA), and D-type natriuretic peptide (DNP, 38AA). They share common features and exhibit tissue distribution of gene expression as well as functional and pharmacological characteristics. The primary sites of synthesis of the NP are the heart and brain; additional extra cardiac and extra cranial sites include intestine and kidney. Membrane-bound guanyl cyclase-coupled NP receptors (NPR) (A- and B- types) are generally implicated in mediating NP effects via the production of cyclic GMP as the intracellular messenger. NPR-C lacking the guanyl cyclase domain may influence the target cell function through inhibitory guanine nucleotide (Gi) protein, and they likely also act as clearance receptors for circulating peptides. NPs are identified as regulatory diuretic-natriuretic substances responsible for salt and water homeostasis and as hormones lowering blood pressure. This review discusses the essential biochemistry, physiological properties of NP and their manifold functional implications in cardiovascular medicine.

Left Atrial-Left Ventricular Bypass for Congenital Mitral Stenosis

The case of a patient with congenital mitral stenosis successfully treated by insertion of a left atrial-left ventricular valved conduit is presented. After insertion of the conduit, pulmonary artery pressure was normal, persistent pulmonary edema and ascites disappeared, and the childs rate of growth and level of activities returned to normal.

An electrocardiographic midterm follow-up study after anatomic repair of transposition of the great arteries

Prospective studies of rhythm and conduction, before and after 1-stage anatomic repair of simple transposition of the great arteries, were performed on 24 survivors. Pre- and postsurgical serial standard electrocardiograms were obtained on each patient. Fourteen patients underwent perioperative 24-hour electrocardiograms; all had follow-up 24-hour electrocardiograms. Rare atrial or occasional ventricular premature complexes were detected in 3 (11%) patients before operation. After surgery, 1 patient developed right bundle branch block. Two patients developed a left bundle branch block. One patient had a QS pattern in V6, which disappeared on follow-up electrocardiogram. Transient second-degree atrioventricular block was detected in 1 patient. A normal P-R interval and P-wave axis were present in all but 1 patient. Mild sinus bradycardia or rare atrial or ventricular premature complexes were detected in 4 of twenty-nine 24-hour electrocardiograms performed in the first 2 years after surgery. At 3 years after repair, 5 patients had a normal 24-hour electrocardiogram and 1 had low-grade ectopy (rare atrial and ventricular premature complexes). At 4 years, all 4 patients studied had normal 24-hour electrocardiograms. During a mean follow-up of 3 years, we have yet to document any symptomatic arrhythmias.

The Prognostic Value of Intraoperative Pressure Gradients with Congenital Aortic Stenosis

Patients with congenital aortic stenosis are subject to sudden death without prior symptoms. Indications for operation are based on pressure gradients, but intraoperative evaluation of results after relief of obstruction can be subjective and arbitrary. Between September, 1981, and October, 1983, 21 patients underwent operation for relief of congenital aortic stenosis. Fifteen had valvular, 4 had supravalvular, and 2 had subvalvular stenosis. Seven patients were 1 year of age or younger, 2 being 3 days old. Preoperative inotropic support and emergency operation were necessary in 2 patients. Intraoperative pressure gradients were measured in all but the 2 patients who were 3 days old. All patients survived without complications. Intraoperative and postoperative pressure gradients were available in 16 patients. The average preoperative pressure gradient was 76 mm Hg. It was significantly lowered to 20 mm Hg (p less than 0.001) intraoperatively, which compared with 15 mm Hg postoperatively. Three patients had an unsatisfactorily high intraoperative pressure gradient after initial intervention. Immediate reexploration and incision of the rudimentary commissure in 2 and excision of redundant valvular tissue in the other resulted in a more satisfactory pressure gradient without substantial aortic insufficiency. We suggest that measurement of intraoperative pressure gradients can accurately assess the results of therapy and allow the surgeon the option of reexploration for further intervention. Moreover, the high correlation between intraoperative and postoperative pressure gradients can help in planning postoperative management and future cardiac catheterizations.