James Geoffrey Stevenson

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. In the remaining infants blood flow characteristics were identical on either side of the line, and catheterization excluded total anomalous pulmonary venous return and cor triatriatum. In all patients who had total anomalous pulmonary venous return, drainage involved a persistent left superior vena cava, and this vascular structure was identified by pulsed Doppler examination from the suprasternal notch. Pulsed Doppler echocardiography appears to be a useful technique for resolution of left atrial lines found on M mode echocardiography.

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. From precordial approach, Doppler evaluations of the main pulmonary artery were also made in search of flow characteristic of patent ductus arteriosus. Doppler detection of flow within the Blalock-Taussig shunts indicated shunt patency, and indicated that continuous turbulent flow in the right pulmonary artery was not due to only patent ductus arteriosus. Shunts were proven patent in 31 patients, occluded in four. Twelve patients also had patent ductus arteriosus. By Doppler, the right pulmonary artery had continuous turbulent flow in 30 of 31 patients in whom the right pulmonary artery was found. From the suprasternal or high parasternal approach, the right Blalock-Taussig shunts were detected by marked continuous turbulent flow directed away from the transducer, between the aortic and superior vena caval flow signals. Left Blalock-Taussig shunts had similar directional continuous turbulent flow. Prosthetic shunts were identified by the dense shunt material. Twenty-four of 31 functional shunts were identified, and all contained continuous turbulent flow. Three left-sided shunts were missed. All four occluded shunts were identified by Doppler, and had no lumen flow within.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulsed doppler echocardiographic evaluation of the cyanotic newborn: Identification of the pulmonary artery in transposition of the great arteries

Abstract During M mode echocardiographic evaluation of cyanotic newborn infants, one may find two ventricles and two great vessels, but not have proof of their identity. Identification of the great vessels is important in evaluation of possible transposition of the great arteries. In a series of 68 cyanotic neonates pulsed Doppler echocardtography was applied to test the hypotheses that (1) a patent ductus arterlosus in present in most cyanotic neonates, (2) the great vessel that receives diastolic ductal flow is the pulmonary artery, and (3) specific noninvasive identification of pulmonary artery will allow diagnosis or exclusion of transposition of the great arteries. On M mode examination, the relations of the great vessels were normal in 43 infants; in all, pulsed Doppler echocardiography detected a patent ductus arteriosus flowing into a normally positioned pulmonary artery. The cyanosis in these 43 patients was later proved to be of pulmonary origin. In eight infants, the relation of the great vessels suggested transposition, and in all eight, Doppler echocardiography detected a patent ductus flowing into the posterior great vessel, proved at angiocardiography to be the transposed pulmonary artery. In 17 patients, the relation of the great vessels was front to back, neither “normal” nor suggestive of classic d transposition. A patent ductus arterlosus, detected with pulsed Doppler echocardiography in all 17, flowed into the anterior great vessel in the 14 normal infants, and flowed into the transposed pulmonary artery in the 3 with proved transposition. It is concluded that ductal patency is prevalent in cyanotic neonates, and that pulsed Doppler echocardiographic detection of ductal flow can define the pulmonary artery; such definition is most helpful in resolving the question of transposition in infants with a relation of the great vessels that is neither normal nor suggestive of transposition.

Acyanotic lesions with normal pulmonary blood flow.

Points useful to the general pediatrician in the differential diagnosis and management are emphasized. The need for exercise limitation, prophylaxis for infective endocarditis, and the urgency for referral are also discussed.

Pulmonary vascular resistance and right ventricular function in canine endotoxin shock.

Summary The pulmonary vascular resistance in herbivores has been reported to increase threefold in endotoxin shock; poor cardiac output has been attributed to cor pulmonale. The poor cardiac output in dogs has been attributed to splanchnic pooling. However, we previously reported that splanchnic pooling was brief, and had resolved, while cardiac output remained low. In the present study of 27 anesthetized dogs we found a marked reduction in cardiac output and aortic pressure following endotoxin, and an increase in systemic resistance to only 125%. Pulmonary arterial resistance rose to a peak of 450% of normal at 5 min, but by 30 min had fallen to 200% of control. The relative contractility of the two ventricles, based on Vmax was equal to or greater than control for most of the 4 hr. Although the afterload for the right ventricle is actually increased, in contrast to a reduction for the left ventricle, contractility for both ventricles was maintained. Treatment with Dextran transiently restored cardiac output, but caused a significant gradual reduction in arterial PO2 as a result of extravasation.

Acyanotic Lesions with Increased Pulmonary Blood Flow

Diagnosis and management of the more common defects such as atrial septal defect, ventricular septal defect, endocardial cushion defect, and patent ductus arteriosus are elucidated.

PULSED DOPPLER ECHOCARDI OGRAPHIC (PDE) EVALUATION OF PATENT DUCTUS ARTERIOSUS(PDA) IN PREMATURE INFANTS

Twenty-eight premature infants, mean weight 1590 grams, were examined by PDE because of concern of PDA. PDE, by supplementing M-mode echo with Doppler flow detection, allows determination of the site of turbulent blood flow. All 14/28 infants with continuous murmurs were found by PDE to have continuous turbulent pulmonary artery flow. 8/28 had only a systolic murmur, but PDE detection of continuous turbulent pulmonary artery flow confirmed PDA in all. 6/28 had no murmur, were examined by PDE because of increasing respiratory requirements, and 4/6 had PDE findings of PDA. 3/6 with no murmur, and 6/8 with only a systolic murmur had abnormally large left atrial dimensions, a significant left to right shunt, and in each the site of shunt could be localized by PDE. The results indicate that the continuous turbulent pulmonary artery flow present in premature infants with PDA can be detected by PDE, that continuous turbulent pulmonary artery flow and a significant shunt may be present with only a systolic murmur or no murmur at all, and that the site of shunt can be detected by PDE. PDE appears to have significant clinical utility in the evaluation of PDA in premature infants, in whom invasive studies carry substantial risk of mortality and morbidity, and may be especially useful when clinical findings and murmurs are not diagnostic of PDA.

DIFFERENTIATION OF APICAL VENTRICULAR SEPTAL DEFECTS (VSD) FROM MITRAL REGURGITATION(MR) BY PULSED DOPPLER ECHOCARDIOGRAPHY (PDE)

Thirty-six youngsters with apical systolic murmurs, whose clinical evaluations did not allow conclusive differentiation between VSD and MR were studied by PDE. The PDE technique, which supplements M-mode echocardiography with Doppler flow detection, allowed determination of the site of turbulent blood flow in 35/36, 97%;. Twenty-one had PDE findings of VSD but no MR, and all 10 who underwent cardiac catheterization had VSD demonstrated. Fourteen youngsters had PDE findings of MR but no VSD, and all 5 who underwent catheterization were found to have MR but no VSD. One youngster had both VSD and MR demonstrated by PDE and catheterization. and one had no abnormalities detected by PDE or invasive study. The sensitivity and specificity of PDE for determining the origin of troublesome apical murmurs has obvious clinical utllity.

FACTORS INFLUENCING DIAGNOSIS |[lpar]|DX|[rpar]| OF VENTRICULAR SEPTAL DEFECT |[lpar]|VSD|[rpar]| BY PULSED DOPPLER ECHOCARDIO-GRAPHY |[lpar]|PDE|[rpar]|

The DX of VSD by PDE can be made by following the harsh VSD jet through the ventricular septum (IVS). The presence of a discrete jet in the right ventricular(RV) apex is presumptive evidence of a low or muscular VSD. 31 youngsters with catheterization proven left to right shunt through isolated VSD were examined by PDE to determine factors influencing ability to DX VSD by PDE. In 24/31, the turbulent VSD jet could be followed through the IVS. In 7/31, harsh systolic flow was found on the RV side of IVS but could not be followed through the IVS. Two of these were apical RV jets, and had a small apical VSD at cath, and 1/7 was a VSD obscured by the tricuspid valve. Four of the 7 were in the usual location, but had higher pulmonary resistance*, pulmonary to systemic resistance ratios**(560±258dynes-sec-cm−5*, 1/7±1.5**) and subjectively less pulmonary artery turbulence by PDE than those whose VSD jets could be followed across the IVS (247±227 dynes-sec-cm−5*. 1/14±5.8**). p=.05*, p=.01**. The DX of VSD by PDE was made in 26/31 youngsters with known VSD, 84%;. The DX could not be made in one whose VSD was under the tricuspid valve, and in 4 whose VSDs were high, but were associated with high resistance. The turbulence of the VSD jet is a useful guide in following VSD flow across the IVS; diminution of turbulence, as may be expected with high pulmonary resistance, may compromise the ability to follow the VSD jet across the IVS.