Tetsuo Sato

Prediction of Peak Pulmonary Artery Pressure by Continuous-Wave Doppler Echocardiography in Infants and Children

SummaryContinuous-wave Doppler echocardiography was used to estimate peak pulmonary artery (PA) pressure in 104 infants and children, aged 4 days to 16 years, with normal hearts (control group) and 43, aged 29 days to 13 years, with various kinds of heart disease (patient group). The Doppler transducer was directed toward the right ventricular outflow tract and angled until the maximal velocity signal was reached. Doppler velocity time intervals were measured as follows: acceleration time (AT), from the onset to the peak of the velocity curve; and ejection time (ET), from the onset to the termination of the velocity curve. In the control group, AT corrected through dividing by the RR interval of the electrocardiogram (ATc), and AT/ET by dividing by the square root of the RR interval (AT/ETc), were independent of body surface area. In the patient group, peak PA pressure had a significant inverse correlation with both ATc (r=-0.78) and AT/ETc (r=-0.87). Thus, AT/ETc derived from continuous-wave Doppler echocardiography is a good quantitative predictor of peak PA pressure in infants and children.

A case of pericardial hemangioma with consumption coagulopathy cured by radiotherapy.

An infantile case of pericardial hemangioma with large pericardial effusion and consumption coagulopathy is described. This is the first reported case of pericardial hemangioma cured by radiotherapy.

Estimation of Right Ventricular Pressure in Children by Thallium-201 Myocardial Imaging Using Single-Photon Emission Computed Tomography

Thallium-201 myocardial imaging using single-photon emission computed tomography was performed to estimate right ventricular (RV) systolic pressure in 34 children (aged 4.1 to 16.1 years, mean 7.9 +/- 2.9). Acquisition of the images was performed using a semicircular arc of 180 degrees. On a short-axis slice, a line drawn perpendicular to the ventricular septum so as to cross the RV free wall showing maximum uptake was defined as the region of interest. Thallium-201 counts in regions of interest over both RV and left ventricular (LV) free walls were measured. The ratio of RV-to-LV peak thallium-201 counts was compared with RV peak systolic pressure and the ratio of RV-to-LV peak systolic pressure measured at cardiac catheterization. Both RV peak systolic pressure and the ratio of RV-to-LV peak systolic pressure correlated well with the ratio of RV-to-LV peak thallium-201 counts (r = 0.95 and 0.96, respectively). The ratio of RV-to-LV peak thallium-201 counts greater than or equal to 0.45 could predict RV pressure overloading with a sensitivity of 92%, and a specificity of 88%. Thus, the quantitative analysis of thallium-201 myocardial imaging using single-photon emission computed tomography permits the noninvasive and accurate estimation of RV systolic pressure in children.

Left ventricular end-systolic wall stress to volume relationship before and after surgical closure of ventricular septal defect

SummaryLeft ventricular function was examined angiographically in 64 patients with ventricular septal defect and 13 postoperative patients with a preoperatively large shunt (postoperative group). The unoperated 64 patients were divided into three groups; small (left-to-right shunt ratio <35%), moderate (35%–50%), and large (>50%). The control group consisted of 27 patients with Kawasaki disease. For assessing left ventricular function, left ventricular shape and the end-systolic wall stress to end-systolic volume index ratio, as well as left ventricular ejection fraction were examined. Left ventricular ejection fraction was higher in the small-shunt group (p<0.05) than in the control group, but normal in the other groups. Left ventricular end-diastolic shape was normal only in the small-shunt group and more spherical in the other groups. The large-shunt group alone manifested more spherical left ventricular end-systolic shape and lower end-systolic wall stress to end-systolic volume index (p<0.001). These findings suggest that the left ventricular dysfunction is present in patients with a left-to-right shunt larger than 50%, but this change was reversible in patients who underwent early repair of ventricular septal defect.

Percutaneous balloon aortoplasty for restenosis after extended aortic arch anastomosis for type B interrupted aortic arch.

A 4-month-old boy underwent a percutaneous balloon aortoplasty for restenosis after extended aortic arch anastomosis for type B interrupted aortic arch (IAA). Balloon aortoplasty resulted in a decrease in the peak systolic pressure gradient across the obstructive segment from 84 mmHg to 19 mmHg and in an increase in diameter from 2.5 mm to 4.3 mm. No complications related to the procedure were observed. We assume that balloon aortoplasty can be effective and safe for relieving postoperative aortic obstruction associated with IAA.

Balloon pulmonary valvuloplasty for double outlet right ventricle with valvular pulmonary stenosis

A male neonate presented with cyanosis. Echocardiograms showed a double outlet right ventricle, an absent outlet septum, a subaortic ventricular septal defect and valvular pulmonary stenosis. Balloon pulmonary valvuloplasty was performed at 19 days of age, resulting in an immediate increase of the systemic arterial oxygen saturation from 67 to 87%. As far as could be found, this is the first report of a patient with a double outlet right ventricle without the outlet septum who was clinically observed and underwent balloon pulmonary valvuloplasty.

Shortening Patterns of the Infundibulum in Valvular Pulmonary Stenosis Before and After Balloon Valvuloplasty

Abstract. We analyzed shortening patterns of the infundibulum in 11 patients with valvular pulmonary stenosis (PS) before and immediately after balloon valvuloplasty and at follow-up. The control group consisted of 32 patients with Kawasaki disease. The valvuloplasty was performed at the age of 5.8 ± 2.9 (mean ± SD) years and a satisfactory relief of obstruction was achieved in each. The follow-up study was done at 1.1 ± 0.2 years after the valvuloplasty. With the use of lateral projection of right ventriculograms, transverse diameters of the midinfundibulum were measured over one cardiac cycle from initiation of the pulmonary valve opening. Indices demonstrating shortening patterns of the infundibulum were as follows: time to the beginning of shortening (TBS), time to the shortest diameter (TSD), and shortening fraction (SF). TBS were prolonged before the valvuloplasty, whereas it was comparable with that in the control group, immediately after the procedure and at follow-up. TSD was increased before and immediately after the valvuloplasty, but it was normalized at follow-up. SF was increased at every observation. Thus, shortening patterns of the infundibulum in PS were characterized by increasing TBS, TSD, and SF. At short-term follow-up following the valvuloplasty, TBS and TSD were normalized, which could be a result of a successful relief of pulmonary obstruction. In contrast, SF remained elevated, which indicates that the musculature of the infundibulum remains hypertrophic up to 1 year after the valvuloplasty.