Sunday Afternoon, April 24, 1955

2:00 P.M. Scientific Session: REGULAR PROGRAM.

7. The Diagnosis of Acquired Valvular Disease by Left Heart Pressure Recordings.

Don L. Fisher (by invitation), Pittsburgh, Pa.

Pressure recordings of the left heart circuit can be safely obtained at left heart catheterization, using transthoracic left atrium puncture by the method of Bjork. A six inch, 18 gauge, thin-walled needle is inserted by a right paravertebral approach in the un-anesthetized patient. The prone position is used with fluoroscopy to check the placement of the needle. A polyethylene catheter is passed through the needle and advanced successively into the left atrium, left ventricle and aorta. Fifty-six patients have been studied by this technique without serious complications. Pressure records demonstrate characteristic changes for each of the acquired left valve lesions as well as evidence of left heart failure. The severity of mitral stenotic obstruction is indicated by the amount of pressure drop across the valve, during ventricular diastole. Mitral insufficiency is measured by the amplitude of the re-gurgitant pulse into the left atrium during ventricular systole. The severity of obstruction in aortic stenosis is indicated by the amount of pressure drop across the aortic valve during the ventricular systolic pulse. Aortic insufficiency widens the aortic pulse pressure and eventually produces increased left ventricular pressure. Left ventricular failure from any cause results in an increased diastolic (filling) pressure. Correlation with findings at heart surgery and at autopsy were used to test the validity of these criteria.

8. A Laboratory and Clinical Evaluation of Operations for Coronary Artery Disease.

David S. Leighninger (by invitation), Cleveland, Ohio

During the past twenty-three years Beck and his associates have established the principles of improving the blood supply to the heart. These are (1) the even distribution of blood by intercoronary arterial communications, (2) elevation of the coronary sinus pressure, and (3) the addition of new blood from outside sources by (a) extracoronary communications and (b) arterialization of the coronary sinus. The intercoronary arterial communications are probably the most important mechanism of benefit. Mautz and Gregg developed a method of study which quantitatively evaluates the functional intercoronary communications by determining the backflow from a major coronary artery. The effect of epicardial abrasion, sinus ligation, arterialization of the coronary sinus, and various irritants such as asbestos, asbestos-like substances, talcum powder, phenol, silver nitrate and urea have been studied by this method. Backflow values in operated dogs were compared to values for a large number of control dogs and the results correlated with other methods of testing. The significance of a small quantity of blood, 3 to 5 cubic centimeters per minute, to an ischemic area of myocardium has been established and the mechanism by which this quantity of blood is beneficial has been determined.

Two operative procedures, the Beck I and II operations, which utilize these mechanisms of benefit, have been applied to over 200 patients with excellent or good results in about 80 per cent. The results in patients can be correlated to the experimental background.

9. Technical Factors Which Favor Mammary-Coronary Anastomosis With Reports of Forty Cases of Human Coronary Artery Disease Thus Treated.

Arthur Vineberg and William Buller (by invitation), Montreal, Que.

At the last meeting of this Association the frequency of mammary-coronary anastomosis and internal mammary artery patency was questioned. This question has been studied for ten years by us. Many hundreds of animals have been operated upon, testing one factor at a time. Many of the factors responsible for thrombosis of the implanted internal mammary artery are now known as well as some of the factors responsible for mammary-coronary anastomosis. These will be discussed under two headings, namely: (1) Preparation of the Artery for Implantation, and (2) Technique of Implantation.

Evidence will be presented to show that with the proper technique of preparation and implantation the artery remains open in 92 per cent of the implants. The incidence of mammary coronary anastomosis seems to be dependent upon pressure differentials and ischaemia. Arteries implanted into normal hearts form mammary-coronary anastomoses in 46 per cent of animals as compared with 71 per cent in ischaemic hearts. Empyema, haemothorax and abdominal distention are complications which tend to cause thrombosis of the internal mammary artery in both animal and man.

Evidence will be shown which indicates that a systemic artery placed within the myocardium of the left ventricle remains open because it bleeds directly into myocardial sinusoidal spaces lying between myocardial fibre bundles. These spaces are opened during the making of the myocardial tunnel.

A short report of results obtained by internal mammary artery implantation in the treatment of 40 human cases of coronary artery insufficiency will be given.

10. Analysis of 50 Patients Treated by Mitral Commissurotomy Five or More Years Ago.

Robert P. Glover, Thomas J. E. O'Neill and O. Henry Janton

(by invitation), Philadelphia, Pa.

The authors performed 50 commissurotomies for mitral stenosis in 1949 and 1950. Each of these patients has been followed to the present time. The purpose of this communication is to present their present status with all pertinent data to include both the present functional and objective findings. Thirty-eight of the 50 patients are living five years or more after surgery. Each has maintained to the present time the degree of subjective improvement noted within the first postoperative year. Twenty-eight of the 38 living patients are considered to be in an excellent functional state and are living relatively normal lives. Nine are considerably improved over their preoperative state and one remains unimproved. Of the 12 nonliving patients six represent an operative mortality during the initial phase of this surgical program. The remaining six died from six months to four years after surgery. Three of these were desperate Stage V cases at the time of surgery; three were in Stage III but presented completely immobile, heavily calcified valves in which an ideal commissurotomy could not be accomplished.

In the opinion of the authors commissurotomy performed properly in cases of pure or greatly predominant mitral stenosis has been of inestimable value to the vast majority of patients so treated. The presented data support the view that initial improvement has been maintained for a five year period; there have been no indications to suggest that this improved state will not continue indefinitely in the future.

11. Evaluation of Techniques for the Repair of Auricular and Ventricular Septal Defects.

Earle B. Kay, Frederick S. Cross (by invitation) and

Henry A. Zimmerman (by invitation), Cleveland, Ohio

The final chapter in the repair of various types of septal defects in the heart is far from complete yet the increasing number of successful closures by various groups attests to the progress that is being made. Concomitant with the development of new surgical techniques is the development of a better understanding by the internist and the surgeon as to the correct timing of operations, and proper operative indications and centra-indications.

Atrial septal defects present a simpler problem in closure than ventricular septal defects due to easier assessibility, lower atrial chamber pressure, and the thinner atrial wall adaptable to utilization in the closed techniques.

It is the purpose of this study to review our experience in the closure of septal defects, both atrial and ventricular, by closed and open methods. Fifteen patients of a wide age range with atrial septal defects of either the septum primum or secundum type have been repaired. All of these defects have been repaired by the closed method utilizing several different techniques. There has been one death in the fifteen cases in this series.

One ventricular septal defect has been repaired by a closed technique, and a beginning experience is being obtained in the use of controlled cross-circulation in the open closure of pure ventricular septal defects, as well as those associated with Tetralogy of Fallot.

Technical aspects of the various methods used will be described, pre and postoperative cardiac catheterization studies as well as clinical evaluations will be presented, and impressions gained to date concerning the indications and contra-jndications to surgery will be discussed.

12. Experiences with Surgical Repair of Atrial Septal Defects.

Elton Watkins, Jr. and Robert E. Gross, Boston, Mass.

The surgical closure of defects in the atrial septum has proved to be a useful procedure which improves the functional status of invalided patients. We have operated upon 35 individuals. These patients presented either incapacitating symptoms or findings suggesting impending difficulty-a large heart, poor body development, serious pulmonary congestion, or catheterization data indicating that right ventricular output was more than twice left ventricular output.

Over ninety per cent of the defects have been located dorsally in the septum, well away from the atrio-ventricular valves. Such malformations have been closed by the external suture methods we have described. Defects near the inferior caval orifice have been closed most easily by placing the inferior sutures through the left atrial wall, which lies close to the anterior lip of the septal orifice. The rare ostium primum defects have been associated with serious deformities of the mitral and tricuspid valve leaflets. We have had no survivals following closure of such defects. An additional hazard is the proximity of the atrio-ventricular node and bundle to the inferior margin of the low-lying defect. The conduction system may be located by landmarks palpable at the time of operation.

Post-operative management has been complicated occasionally by left ventricular failure controlled by digitalization and limitation of fluid and sodium intake. Evidence suggests that the syndrome is related to poor development of the left ventricle over the years when the septal defect prevented adequate filling of the growing ventricle.