ABSTRACTS

A VIDEO SCANNER-ANALOG COMPUTER SYSTEM FUR THE ANALYSIS CW ECHOCARDIOGRAPHIC CRITSIUAPOR NORMALNEWBORN INFANTS

ROUTINE ECHOCARDIOGRAMS. James M. Griffith, MSEE, Walter Arthur D. Hagan, CDR, WC, USN and William J. Ceely, L. Henry, MD, National Heart and Lung Inst., Bethesda, Md. CDR. MC, USN, Naval Hospital, San Diego, California

A major reason for the expanding use of echocardiography (ECHO) in cardiac diagnosis is that rapidly moving cardi- ac structures can be visualized with ease and safety. Typically, ECHO studies have been limited to qualitative observations because detailed quantitative measurements of cardiac structure motion have been possible only through laborious and time-consuming manual information processing. We have developed a video scanner-analog com- puter system that greatly simplifies ECHO analysis. Up to 8 non-overlapping cardiac structures first are traced manually from routine ECHO's onto transparent paper. This traced record then is converted by a television (TV) cem- era into a TV picture consisting of 524 video lines. These video lines are processed sequentially by 8 indivi- dual signal detectors, each generating a digital value proportional to the distance of each traced signal from the beginning of the video line. The digital data is converted to analog form, processed using analog computer techniques, end recorded on a strip chart. Using this system, we analyzed 20 routine ECHO's and compared the results with manual analysis. Mean velocity of circum- ferential fiber shortening (VCF), maximum VCF, instentan- eous transverse LV dimension (TLVD), instantaneous esti- mated LV volume ([TLVD13) and the derivative of mitral valve motion were all accurately obtained (r>O.95). In addition, other physiological data recorded on the ECHO record, such as EKG and pressures, may also be analyzed in conjunction with cardiac structure motion (allowing, for instance, the construction of force-velocity curves). The use of this system to analyze in detail the motion of a variety of individual and paired cardiac structures may allow important cardiac diagnostic information to be ob- tained easily from routine echocardiogrems.

MECHANISMS OF SYMPTOMATIC IMPROVEMENT AFTER CORONARY BYPASS GRAFT SURGERY. Lawrence Griffith, MD; Stephen Achuff, MD; J. O'Neal Humphries, MD,FACC; Richard Conti, MD, FACC; Robert Brawley, MD; Vincent Gott, MD; and Richard Ross, MD,FACC; Johns Hopkins Hospital, Baltimore, Md. Evaluation of 71 patients 6.120.8 months after saphenous

vein bypass graft(SVBG) surgery demonstrated that 46 pa- tients(65%) had at least one new total occlusion(NT0) of a segment of a major coronary artery (right, anterior des- cending or left circumflex) that was patent before surgery. SVBG patency rate was 66%(79/120). Fifty-six of these 71 patients had symptomatic improvement(S1) as determined by objective stress testing (exercise and/or atria1 pacing). Two mechanisms of SI were identified: Group I (16 pa-

tients)- improved blood flow through a patent SVBG into an intrinsic coronary artery(ICA) whose arteriographic appear- ance was unchanged from pre-op study; Group II (9 patients)- all SVBG were occluded and there was a NT0 of the ICA into which the SVBG was placed with probable infarction of the corresponding ischemic ventricular segment; Group III (31 patients)-an intermediate group with a combination of these two mechanisms. Six patients in the intermediate Group III had all grafts

patent and the only change in the ICA was a NT0 of a small segment of artery proximal to the anastomosis. Im- provement here is probably due to increased flow. Also in Group III are 20 patients with two grafts, one of which is open to an unchanged native circulation while the other SVBG is occluded and the corresponding ICA segment has a NTO. Improvement here may be due to increased flow or infarction, or a combination of both. There are also five patients in Group III with only one graft patent that fills only a coronary segment proximal to the anastomosis with a NT0 of the distal segment.

Changes in the intrinsic coronary artery and possible infarction of ischemic myocardium likely play a role in SI in some patients following SVBG surgery.

Two hundred normal infants between 12 and 72 hours of age were studied to establish normal ranges for all cardiac parameters which can be evaluated by ultrasound. Strip chart recording technique was employed utilizing a 5 megahertz transducer. Specific dimensions were as follows: right ventricular end-diastolic wall thickness ranged 2 to 4.2 ssn, average = 2.7 11111; right ventricular end-systolic wall thickness ranged 3.3 to 6.1 nun, average = 4.6 1111; right ventricular end-diastolic dimension ranged 9.3 to 16.3 mm, average - 12.5 sun; right ventricular end-systolic dimension ranged 7.3 to 11.3 Amy, average L 9.7 11111; pulmonary artery diameter ranged 9.6 to 12.8 11111, average = 11.3 w, tricuspid valve excursion ranged 9 to 13.3 rms, average = 10.9 w; tricuspid valve velocity ranged 50 to 100 rma/sec, average = 68 mm/set; ventricular septal thickness ranged 2.3 to 3.3 lam, average = 2.7 nun; aortic root diameter ranged 8.3 to 11.3 nm, average * 10.1 nmu left atria1 diameter ranged 4 to 8.8 nxn, average = 6.1 rmn; anterior mitral leaflet excursion ranged 8.7 to 12.1 asa, average - 10 nm; anterior mitral leaflet velocity ranged 51 to 105 mm/sac, average = 74 mm/set; left ven- tricular end-diastolic wall thickness ranged 1.6 to 3.3 om, average = 2.5 snn; left ventricular end-systolic wall thickness ranged 2.8 to 5 sm~, average = 3.7 nm~; left ventricular end-diastolic dimension ranged 16 to 21.1 nfs, average = 18.2 snn; left ventricular end- systolic dimension ranged 10 to 15.3 sm, average = 13.5 arm. In conclusion, all valves were consistently identified and chamber dimensions, including wall and septal thickness, accurately measured in most infants.

THE LEFT VENTRICLE AND CORONARY ANATOMY IN PATIENTS WITH CORONARY ARTERY DISEASE AND I NTRAVENTRI CULAR CONDUCTI ON 01 STURBANCES Robert I. Hamby, MO, FACC; Farouk Tabrah, MO; Mohinder Gupta, MO, Long Island Jewish-Hillside Medical Center and Queens Hospital Center Affiliation, New York City, N.Y.

The hemodynamic and angiographic findings of 42 patients with coronary artery disease (CAD) and an intraventricu- lar conduction disturbance (IVCO) is reported. Right bundle branch block (RBBB) was present in six, left ante- rior hemiblock (LAH) in eighteen, LAH with RBBB in nine and left bundle branch block (LBBB) in eight patients. One patient had RBBB with left posterior hemiblock (LPH). Congestive heart failure, cardiomegaly and trifascicular block were common with LBBB and LAH with RBBB. The RBBB group had normal LV hemodynamics, end-diastolic volume (EOV) and ejection fraction (EF) together with predomi- nant three-vessel disease. The LAH group, especially with evidence of a transmural infarction, had abnormal LV hemodynamics, EOV and EF. More than half the LAH group had single vessel disease. The LBBB group and RBBB with LAH group uniformly had abnormal LV hemodynamics, EOV and EF and the majority of these patients had double or triple vessel disease. The patient with LPH and RBBB had normal LV function. Al I the patients with abnormal LV function had anterior and/or apical wall asynergy. All the patients, except the one with LPH and RBBB, had sig- nificant left anterior descending (LAO) disease. It can be concluded that the hemodynamic derangement in these patients is correlated more with the IVCO than the ex- tent of the CAD, especially when the latter was associ- ated with a myocardial infarction. The only predictable aspect of the CAD is the finding of significant LAO artery disease in all but one patient.

January 1973 The American Journal of CARDIOLOGY Volume 31 137