Langford Kidd

Cardiac involvement in adolescent hypertension. Echocardiographic determination of myocardial hypertrophy.

SUMMARY We measured left ventricular chamber dimension and wall thickness using M-mode echocardiography in 61 adolescents with systolic or diastolic blood pressures above the 90th percentile for age and sex and in 49 norraoteosive adolescents. Left ventricular posterior wall and ventricular septal thickness indexed to body surface area were significantly greater (p < 0.001) in the hypertensive group than in the nonnotenslve controls. Left ventricular chamber diastolic and systolic dimensions were not different in the hypertensive group when compared to nonnotenslve adolescents with comparable body size. Left ventricular diastolic and systolic volumes as well as left ventricular function did not differ between the hypertensive and control groups. Calculated parameters of left ventricular hypertrophy, namely, the radlus-to-wall-thlckness ratio, crosssectional muscle area, and left ventricular mass, in the hypertensive adolescents were all significantly different (p < 0.001) from those in toe control groups. The finding of myocardial hypertrophy in young, mildly hypertensive subjects suggests early myocardial involvement in the hypertensive process.

An Evaluation of Parental Concerns and Misperceptions About Heart Murmurs

This study sought to determine the extent of anxiety and misperceptions about heart murmurs for consenting parents of 182 children referred for first-time pediatric cardiology assessment (including echocardiography) of a heart murmur. From questionnaires completed before assessment, 22% of parents indicated that they were extremely concerned, and only 16% could define a heart murmur as a sound made by the heart. From 1-month follow-up questionnaires obtained from parents of children without heart disease at assessment, 10% continued to believe that their child had a heart problem. Cardiology assessment may not provide complete reassurance to all families and additional interventions may be necessary.

Ventricular septal defect: Clinical and hemodynamic changes in the first five years of life

Abstract Two hundred consecutive infants with isolated ventricular septal defects were assessed clinically and hemodynamically and then followed throughout the first 5 years of life. Those infants who had flow ratios less than 2 to 1 generally became asymptomatic because of diminution in size of the defect. Complete closure occurred spontaneously in 20 per cent. The majority of infants had flow ratios greater than 2:1 and in these the natural evolution varied. At least 15 per cent of these infants may die from their cardiac lesion in infancy. However, approximately 40 per cent of those who survive will have closed defects, and 20 per cent of those who show this reduction in size will have spontaneously closed defects by 5 years of age. Those children in whom the large defect persists remain symptomatic and fail to thrive. There is little or no change in clinical, radiologic, or electrocardiographic findings up to the time of surgery, but hemodynamic reassessment indicates that at least 20 per cent of such children may develop progressive pulmonary arteriolar disease and that such changes, when they are going to occur, will be evident hemodynamically in the second year of life. When all the children with flow ratios greater than 2 to 1 are considered, the mortality rate was 7 per cent; 9 per cent required palliative surgery in infancy; 6 per cent underwent spontaneous closure; and 10 per cent developed the Eisenmenger reaction.

Differentiation of Tumor from Viable Myocardium using Cardiac Tagging with MR Imaging

We report the application of myocardial tagging by MR to define tissue planes and differentiate contractile from noncontractile tissue in a neonate with congenital cardiac rhabdomyoma. Using custom-written pulse programming software, six 2 mm thick radiofrequency (RF) slice-selective presaturation pulses (tags) were used to label the chest wall and myocardium in a star pattern in diastole, approximately 60 ms before the R-wave gating trigger. This method successfully delineated the myocardium from noncontractile tumor, providing information that influenced clinical management. This RF tagging technique allowed us to confirm the exact intramyocardial location of a congenital cardiac tumor.

The hemodynamics in ventricular septal defect in childhood

Abstract (1) Hemodynamic groups are defined, and the frequency in a “catheter laboratory population” of isolated ventricular septal defects is described. The cases of 247 patients 1 to 16 years old are analyzed and considered, together with 151 previously presented cases of patients under 1 year of age. (2) A natural history is suggested; the majority of septal defects are benign; some defects get smaller or close; a few patients develop progressive pulmonary vascular obstruction. (3) The pulmonary vascular obstruction may progress after surgical closure of the defect. (4) No “congenital Eisenmengers” were found. (5) Those who developed progressive pulmonary vascular obstruction had greatly increased pulmonary blood flow early. (6) It is recommended that a careful watch be kept on “high-flow” patients in the first few years of life, and that they be restudied early to pick out the developing Eisenmenger reaction, with a view to prompt operation.

Circulatory Effects of Propranolol in Children with Fallot's Tetralogy Observations with Isoproterenol Infusion, Exercise and Crying*

Abstract Twenty-five children with Fallots tetralogy ranging in age from 10 months to 14 years were studied during diagnostic cardiac catheterization and angiocardiography. The effects of exercise, beta adrenergic stimulation with isoproterenol, and crying upon arterial oxygen saturation, pulmonary and systemic blood flow and the right to left shunt were determined before and after beta adrenergic blockade with propranolol. Both exercise and isoproterenol infusion resulted in a drop in arterial oxygen saturation and an increase in the right to left shunt. Propranolol, in doses which abolished the response to isoproterenol, produced a small rise (5–10%) in resting arterial oxygen saturation in 12 of 15 cases. The hemodynamic effects of exercise, however, persisted although they were less pronounced, in 4 of 6 cases. Crying in 2 infants was accompanied by a large drop in arterial oxygen saturation which was considerably reduced following administration of propranolol. It is concluded that beta adrenergic blockade with propranolol has little to offer in the management of older patients with Fallots tetralogy; it may have some value in treating young infants and children, especially those with hypoxic spells.

Management of aortic arch interruption with prostaglandin E1 infusion and microporous expanded polytetrafluoroethylene grafts

Prostaglandin E1 infusion and a microporous expanded polytetrafluoroethylene graft were used in the management of eight infants, all less than 4 days old, with interruption of the aortic arch. Five of the six infants receiving prostaglandin E1 responded dramatically to this therapy, with return of lower limb pulses and lessening of metabolic acidosis. There were no adverse effects attributable to the prostaglandin E1 infusion. Seven infants subsequently underwent aortic reconstruction with a polytetrafluoroethylene graft. There were no operative deaths, and in up to 3 years of follow-up of these patients, graft obstruction occurred in only one patient and this graft was successfully revised. The long-term mortality rate was high (62 percent); all deaths but one were attributable either to the palliation or to the total correction of the associated cardiac malformations.

VENTRICULAR SEPTAL DEFECT IN INFANCY: A HEMODYNAMIC STUDY.

Abstract The hemodynamic data are reported in 151 infants in whom the sole diagnosis was ventricular septal defect, and who underwent cardiac catheterization before the age of 1 year. Seventy-eight per cent had pulmonary to systemic flow ratios over 2:1, and in 16 per cent the low pulmonary blood flow (flow ratio under 2:1) was due to a small defect. Fifty-nine per cent of the patients had low or normal total pulmonary vascular resistance, and in only 25 per cent was the resistance increased above normal for this age group. Twenty-five of the patients were recatheterized subsequently, and it was found that in three the defects had achieved functional closure. Two patients who were in the group with low flow and high resistance at the time of the first study had lower resistance later. Of the 14 patients who demonstrated increasing pulmonary vascular resistance, 10 had low or normal resistance earlier. It is suggested that progressive pulmonary vascular obstruction is a sequel to high flow and low vascular resistance in the pulmonary circulation and is not present from the time of birth. It is proposed that such patients be subjected to serial study in order to define those who are reacting to the pressure-flow stimulus in this way.

Determinants of outcome in hospitalized infants with congenital heart disease

To identify determinants of adverse outcome in this era of early, definitive treatment, retrospective data were analyzed for 1988 on infants aged less than 1 year with congenital cardiac disease hospitalized at The Johns Hopkins Hospital. In this cohort of 108 infants, 34% (37 of 108) had complex cardiac disease, 33% (36 of 108) had major extracardiac anomalies, 88 patients (81%) underwent 116 surgical procedures, 37% (40 of 108) were hospitalized for greater than 28 days and 29% (31 of 108) died during the first year. Univariate analysis showed that complex disease (i.e., severe ventricular hypoplasia, ventricular septal malalignment or outflow atresia), extracardiac anomalies, early initial presentation, and prolonged stay in the intensive care unit were significantly associated with infant death, whereas surgery was associated with a significantly increased rate of survival. The findings for complex disease and surgery persisted in multiple logistic regression analysis. It is concluded that outcome in most infants with congenital cardiac defects is now extremely favorable, and that major research and preventive efforts should focus on complex congenital cardiac defects.

Effect of Ventricular Septal Defect and Patent Ductus Arteriosus on Left Ventricular Pressure in Complete Transposition of the Great Vessels

The relationship between the pressures in the left and right ventricles was examined in 80 infants and children who had complete transposition of the great vessels and in whom the presence of a ventricular septal defect or a patent ductus arteriosus was known. All children with obstruction to left ventricular outflow have been excluded. It was found that 92% (34 of 37) of the children with transposition and a ventricular septal defect had left ventricular pressures greater than 70% of the systemic, while 45% (10 of 22) of those with a patent ductus and only 5% (1 of 21) with a closed ventricular septum and no ductus, had pressures in this range. Seventy-six per cent (16 of 21) of the children in this last group had left ventricular pressures less than 50% of the systemic pressure. It is concluded that infants with transposition of the great vessels and a ventricular septal defect stand in high risk of developing obstructive pulmonary vascular disease and therapy should be guided accordingly.