Electrokymograph for recording heart motion utilizing the roentgenoscope

Abstracts and Reviews Selected Abstracts Henry, ing

G. C., and Boone, the Roentgenoscope.

A. A.:

Electrokymograph

for

Am. J. Roentgenol.

Recording

Heart

Motion

Utiliz-

54: 217 (Sept.), 1945.

Although graphic recording of the motion of the heart and great vessels has been a longdesired goal, this method has not been used extensively because of analytic difficulties in the size, clarity, and brcvity.of the recorded waves to be examined on the kymogram and the time-consuming nature of the analysis. The authors have developed a method which overcomes these difficulties and produces a large, beam type or electrocardiographic type of tracing on bromide paper of a chosen point of the cardiac silhouette. Under the roentgeqoscope, the diaphragm of the electrokymograph, which contains a narrow slit, is aligned at right angles to the particular portion of the heart border to be investigated. As the heart beats, its border moves back and forth across the slit, varying the intensity of the roentgen rays passing through it. If the intensity of these rays were recoided with distortion in respect to a time axis we would have an indication of the motion of this portion of the heart border. This is accomplished by a 931-A multiplier phototube, used by Morgan in his exposure meter for roentgenography. A strip of fluorescent screen is placed directly over the photosensitive area of the 931-A tube. As roentgen rays strike the tube, the cathode is illuminated. When the shadow of the heart border moves inward (contractile motion) this strip of screen is further irradiated by the beam. Thus, the total light emitted is proportional to the changes in the position of the heart border. The current output is amplified and recorded by a galvanometer. Tracings of the carotid pulse are recorded simultaneously to align curves from separate points on the cardiac border in respect to the time relations in the cardiac cycle. Sample records are presented which represent the motion of the left ventricular border, the pulmonary artery, the aortic knob, and the right auricular border. These are aligned, one above the other, by the carotid pulse tracing, so that events or different records.falling on any given vertical line occur at the same time. The wave forms for each of the border areas of the heart are found to be characteristic of that particular arca and they resemble closely the respective volumetric wave forms found in physiology texts. These authors expect to present more detailed information regarding the individual chambers of the heart in subsequent papers. SERBER. Bobson, C.: Trented

Subacute Bacterial With Penicillin.

Endocarditis

Complicated

by Pregnancy,

Am. J. Obst. & Gynec. 51: 427 (March),

Successfnlly

1946.

The patient, a 24-year-old gravida ii, para 0, entered the hospital Jan. 2, 1945, for a therapeutic abortion. She gave a history of having had a cold for the preceding two weeks, complicated by backache, low-grade fever, nausea, and occasional tenderness in several of the digits. She presented evidence of rheumatic mitral and aortic disease, and two blood cultures were positive for Streptococcus tiridans. Penicillin administration was begun on Jan. 14, 1945; 200,000 Oxford units were given daily in divided doses. On January 13, the blood culture was negative. Repeated subsequent cultures were negative. After five weeks of penicillin therapy her progress was not satisfactory, and it was considered advisable to interrupt the pregnancy, which was 399