Quantitative perfusion imaging assessing acquired discrete peripheral pulmonary artery stenosis.

We present the case an 8-yr-old boy evaluated for anastomotic stenosis of the right pulmonary artery after surgical repair of hemitruncus at 6 wk of age. Pulmonary angiography revealed only mild narrowing and a 10-mm pressure gradient across the anastomosis, but quantitative perfusion imaging demonstrated that the right lung only received 16% of pulmonary blood flow. Subsequently, balloon angioplasty of the anastomotic site was performed, resulting in complete resolution of the stenosis and gradient.

Potentially serious drug interactions secondary to high-dose diltiazem used in the treatment of pulmonary hypertension.

Two patients had potentially serious drug interactions (phenytoin, digoxin) that were probably attributable to changes in pharmacokinetics and pharmacodynamics caused by high-dose calcium channel blocker therapy (diltiazem) in the treatment of pulmonary hypertension. Even in the approved normal dosages for the treatment of angina and hypertension, calcium channel blockers are known to cause significant changes in the metabolism of other drugs. Currently, no data exist on the effects of the very high dosages of these drugs, administered to patients with pulmonary hypertension, on the metabolism and clearance of other agents, although, based on our experience and literature reports, recommendations for monitoring therapy can be made.

Functional implications of the pulmonary microcirculation. An update.

The microscopic anatomy of the pulmonary circulation was reviewed, comparing the evidence for two competing models, the sheet-and-post paradigm and the tubular paradigm. Implications of the two paradigms were analyzed for function, including flow, recruitment, distension, and diffusion. We conclude that the pulmonary microcirculation is not essentially different from the systemic microcirculation except that two layers of tubular capillaries are arranged on a central layer of connective tissue, the alveolar wall.

Surgical repair of anatomically corrected malposition of the great arteries.

Anatomically corrected malposition of the great arteries is a rare malformation in which the aorta and pulmonary artery arise from their appropriate ventricles but in an abnormal spatial relationship. This report describes 2 patients with anatomically corrected malposition who underwent closure of a ventricular septal defect and placement of a right ventricle-pulmonary artery conduit. A review of the literature indicates that surgical results have been good (92% survival) in those patients with situs solitus and atrioventricular concordance [S,D,L].

Doppler pressure gradient estimation in children. Accuracy, effect of activity and exercise, and the need for sedation during examination.

Noninvasive estimation of pressure drop has been shown to be an accurate and useful application of Doppler echocardiography. Most accuracy series have used patient-sedated catheterization gradient measurements as the standard of reference. Doppler gradient estimates, however, are commonly made without sedation of the patient when hemodynamics may differ from those present at catheterization.

Tetralogy of Fallot: selective staged management.

One hundred twenty-four patients with tetralogy of Fallot have undergone either primary total repair (61), shunt and later repair (30), or an initial shunt (33). The mean ratio of pulmonary anulus to descending thoracic aorta increased from 0.80 +/- 0.

Noninvasive estimation of peak pulmonary artery pressure by M-mode echocardiography.

In an attempt to predict peak pulmonary artery pressure from routine M-mode echocardiographic tracings, 95 infants and children with congenital heart disease were examined. Following the Burstin method for prediction of peak pulmonary artery pressure, which was originally based on the phonocardiogram and jugular phlebogram, M-mode echocardiography was used to measure the interval from pulmonary valve closure to tricuspid valve opening, namely, the period of isovolumic diastole. The measured interval was plotted on a modified table relating the interval, heart rate and predicted peak pulmonary artery pressure.

Hemodynamic effects of ketamine in children with congenital heart disease.

Pulmonary and systemic vascular responses to ketamine (2 mg X kg-1, intravenously) were studied during cardiac catheterization in 20 children with congenital heart lesions. Pulmonary and systemic resistances (Rp, Rs), ratios between pulmonary and systemic flows (Qp/Qs), and left to right (L----R) and right to left shunts (R----L) were calculated before and after ketamine administration. Statistically significant (P less than 0.

Pulsed Doppler echocardiographic evaluation of ventricular septal defect patches.

Doppler echocardiography has been shown to have high sensitivity and specificity for noninvasive detection of the flow disturbance of ventricular septal defect. After surgery for ventricular septal defect, one might expect loss of the ventricular septal defect flow disturbance. We used two-dimensional and pulsed Doppler echocardiography to evaluate 30 children undergoing surgery for ventricular septal defect to determine postoperative Doppler findings and the effect of ventricular septal defect patch material on those findings.

Arteriohepatic dysplasia: phenotypic features and family studies.

Arteriohepatic dysplasia (AHD) is a disorder characterized by intrahepatic cholestasis and peripheral pulmonary artery stenosis. We have reviewed the phenotypic features in the 56 previously reported cases and 7 persons from our institutions with AHD to summarize the type of cardiac, hepatic, facial, ocular and skeletal manifestations observed in this disorder. Family studies evaluating first-degree relatives of patients with AHD are compatible with an autosomal dominant mode of inheritance with reduced penetrance and variable expressivity.

Noninvasive determination of pressure gradients in children: two methods employing pulsed Doppler echocardiography.

Pulsed Doppler echocardiography has been considered poorly suited for high velocity blood flow measurement, because of the problem of signal aliasing. Two methods for reduction of aliasing in a pulsed system were evaluated in an attempt to measure flow velocities characteristic of significant pressure gradients. With the angle correction method, carrier frequency, pulse repetition frequency and intercept angle were manipulated using a commercially available two-dimensional pulsed Doppler system.

Noninvasive evaluation of Blalock-Taussig shunts: determination of patency and differentiation from patent ductus arteriosus by doppler echocardiography.

Pulsed Doppler echocardiography has been used to detect continuous turbulent flow in the right pulmonary artery after Blalock-Taussig shunts. Since continuous turbulent flow could also arise from patent ductus arteriosus (frequently present in the neonate), continuous turbulent flow in the right pulmonary artery is not specific for Blalock-Taussig shunt function. We evaluated 35 Blalock-Taussig shunts from suprasternal or high parasternal approach for flow in the right pulmonary artery, and in the Blalock-Taussig shunts themselves.

Pulmonary microcirculation: tubules rather than sheet and post.

We examined latex casts of the pulmonary microcirculation with the scanning electron microscope (SEM). Mature rats were anesthetized and ventilated; the pulmonary vasculature was washed out with lactated Ringer solution and then filled with a mixture of Geon latexes. The airways were filled with glutaraldehyde with resulting transmural vascular pressures of 10 cmH2O.

Left ventricular performance in endotoxin shock in dogs.

Endotoxin shock, with maximal velocity of contraction (Vmax) as our index of contractility, showed no myocardial depression in an earlier 4-h study (Guntheroth, Proc. Soc. Exp.

Prognosis in primary ventricular tachycardia in the pediatric patient.

Five male pediatric patients with primary ventricular tachycardia are described. Although three were initially in congestive heart failure due to the tachycardia and were extremely difficult to manage, all have completely recovered, are not taking medication, and are free of arrhythmia. Three of the patients required long-term management with quinidine, with a therapeutic goal of controlling the heart rather than abolishing the arrhythmia.

Evaluation of ejection murmurs by pulsed Doppler echocardiography.

A common problem is a soft basal ejection murmur in an asymptomatic child with a normal electrocardiogram and chest x-ray films. If the diagnosis is aortic stenosis, there is a need for prophylaxis for subacute bacterial endocarditis and concern about development of calcific aortic stenosis. In 40 consecutive children referred for this differential diagnosis, aortic stenosis was diagnosed in 30, based on an ejection murmur at the second right interspace (not necessarily louder than at the second left), which transmitted well to the neck, accompanied by a normal second heart sound.

The role of respiratory infection in intrathoracic petechiae. Implications for sudden infant death.

Intrathoracic petechiae are characteristic of the postmortem changes found in sudden infant death syndrome. The presence and distribution of these petechiae have been claimed as evidence for airway obstruction as the mechanism of death. In a group of young, mature rats that were free of infection, hypoxic asphyxia produced an insignificant number of petechiae, whereas in all littermates infected with an enzootic virus (Sendai) large numbers of petechiae with hypoxic asphyxia developed.

Pulsed Doppler echocardiographic diagnosis of patent ductus arteriosus: sensitivity, specificity, limitations, and technical features.

To determine the diagnostic features, sensitivity, and specificity of pulsed Doppler echocardiographic (PDE) diagnosis of patent ductus arteriosus (PDA), 110 infants with heart disease were examined by PDE from the precordial and suprasternal notch approaches. On precordial examination, PDA was diagnosed upon recording of diastolic ductal flow into the pulmonary artery. From the suprasternal approach, PDA was suspected upon recording of continuous turbulent flow in the right pulmonary artery.

Pulsed Doppler echocardiographic detection of total anomalous pulmonary venous return: resolution of left atrial line.

During precatheterization M mode echocardiographic examination, 33 infants were identified as having findings including right ventricular enlargement and presence of a line within the left atrial portion of the M mode tracing suggesting the possibility of cor triatiatum or total anomalous pulmonary venous return. Pulsed Doppler echocardiography was used to sample blood characteristics on either side of the left atrial line to determine which line was artifactual and which was indicative of an important structure. Five patients whose blood flow characteristics were different on either side of the left atrial line were subsequently proved to have total anomalous pulmonary venous return at cardiac catheterization.

The significance of carotid bruits in children: transmitted murmur or vascular origin, studies by pulsed Doppler ultrasound.

Forty-four youngsters with precordial murmurs and carotid bruits were evaluated clinically and independently, using pulsed Doppler ultrasound. The precordial murmur was evaluated with M-mode echocardiography combined with Doppler flow evaluation, and the carotid bruit was evaluated with peripheral vascular sector scan with Doppler flow evaluation. These ultrasonic techniques can identify abnormal blood flow at anatomic sites such as the aortic valve and in the carotid arteries.

Noninvasive detection of pulmonary hypertension in patent ductus arteriosus by pulsed Doppler echocardiography.

Twenty-five patients with proven patent ductus arteriosus were examined by pulsed Doppler echocardiography (PDE) before invasive assessment. Ten patients had normal pulmonary artery pressures, and by PDE, pandiastolic ductal flow. Fifteen patients had elevation of mean pulmonary artery pressure, and by PDE, all had abbreviations of diastolic ductal flow.