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.
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.
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.
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.
SUMMARYA 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 1-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. Additional Indexing Words:Cardiac segmental diagnosis Ultrasound cardiography Noninvasive techniquesTransposition of the great arteries IN AN EARLIER REPORT the atrioventricular and semilunar valves were used as ultrasonic landmarks to obtain an echocardiographic profile of the heart and its great arteries in the normal neonate.' Since that study, additional uses of the atrioventricular and semilunar valves have resulted in our being able to predict the character of the internal cardiac From the Cardiology Section, Norton-Children's Hospital, and
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