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Radionuclide equilibrium gated ventriculograms were performed in 23 infants before and after surgery for congenital heart disease using standard parallel hole general purpose collimation followed by a pinhole collimation technique to magnify images and improve spatial resolution. A second group of nine infants had pinhole collimated gated ventriculography during cardiac catheterization for comparison with cineangiographic ejection fraction. In group I, pinhole collimation gave improved ventricular and atrial separation over general purpose parallel collimation for determination of left ventricular ejection fraction (42 of 42 studies calculable vs 37 of 42) and for right ventricular ejection fraction (36 of 37 studies calculable vs 20 of 37). In patients with transposition, pinhole technique allowed right ventricular ejection determination in nine of nine studies but in only one of nine was right ventricular ejection fraction possible by standard parallel collimation. In group II, the correlation between left ventricular ejection fraction by cineangiography and pinhole radionuclide ventriculography was excellent (r = 0.95). The correlation for right ventricular ejection fraction between cineangiography and pinhole radionuclide ventriculography was 0.82. Pinhole radionuclide ventriculography is a useful, practical clinical tool that can be used to assess ventricular function in small infants in an intensive care or outpatient setting.

By means of postoperative radionuclide angiography we identified a subset of infants undergoing primary repair of their ventricular septal defects (VSD) who had postoperative morbidity and ventricular dysfunction. Twenty-three consecutive infants undergoing repair of an uncomplicated VSD were studied. Radionuclide-determined postoperative ventricular dysfunction (VD), as defined by a left ventricular ejection fraction less than 0.30 2 to 4 hours after surgery, was correlated with clinical signs of postoperative morbidity. Six patients developed postoperative VD. Clinical correlates of VD included the use of postoperative inotropic support, increased number of postoperative intensive care days, and a low growth rate 3 months postoperatively. Potential predictors of VD were evaluated. A preoperative pulmonary-to-systemic blood flow ratio (Qp/Qs) greater than 3.0 and a pulmonary-to-systemic vascular resistance ratio (Rp/Rs) less than 0.20, taken in combination, gave a positive predictive value for VD of 100%. It is concluded that the preoperative Qp/Qs and Rp/Rs can be used to predict those infants at risk for postoperative morbidity following repair of their VSD.

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)