Hisao Tada

Real-time observation of cardiac movement and structures in congenital and acquired heart diseases employing high-speed ultrasonocardiotomography

Echocardiography has proved useful for cardiac diagnosis during the past several years; however, the conventional one-dimensional ultrasound pulse echo method cannot easily visualize the anatomical relationships of the various cardiac structures. To overcome the limitation, the authors attempted a real-time observation of cardiac structures and introduced high-speed ultrasonocardiotomography with a Sonolayergraph Model SSL-51H (Toshiba) having a logarithmic amplifier. Thirty sector images are produced per second by a mechanically operated, single flat or 75 mm. focus transducer measuring 10 mm. in diameter. The angle of a sector image composed of about 120 scanning lines is arbitrarily changeable from null to 65 degrees. The fast succession of images produced enables clear observation of the movement of cardiac structures in real time. Study of 230 patients by means of the proposed system suggests that it is advantageous as a quick method to provide two-dimensional echocardiograms for cardiac diagnosis and assessment, especially in noninvasive diagnosis.

Clinical study on the flow murmurs at the defect area of atrial septal defect by means of intracardiac phonocardiography.

In order to study flow murmurs through atrial septal defects, right heart catheterization was performed on 48 patients of secundum type, four of primum type, and five of probe-patent foramen ovale, with the double-lumen phonocatheter of Lewis, at the tip of which barium titanate was mounted. The flow murmurs at the defect area were classified into three patterns: v murmur, atriosystolic murmur, and mid-diastolic murmur. V murmur was continuous, extending from late systole to diastole, of low to medium pitch, closely related to atrial v wave and augmenting with expiration. It had no significant correlation to the ratio of left-to-right shunt. It was recorded in 32 out of 48 cases of secundum type and one of primum type, but not observed in probe-patent foramen ovale. Atriosystolic murmur was noted in 17 of 48 cases of secundum type and one of primum type. It was connected with atrial a wave. Mid-diastolic murmur was found at the defect area in four subjects of secundum type. It was thought to be an independent entity from v murmur and to be another one due to shunt flow through the septal defect, since it had no relation to v wave but it was localized between v and a waves in the pressure curve of the right atrium. It is different in localization from mid-diastolic murmur due to relative tricuspid stenosis at the inflow tract of right ventricle.