Late results following direct coronary artery surgery

ABSTRACTS

myocardial oxygen delivery may be enhanced. It is unknown whether this is due to a growth of new coronary collaterals, an increased capacity of existing collaterals or to other mechanisms.

Late Results Following Direct Coronary Artery Surgery GEORGE J. REUL, MD; GEORGE C. MORRIS, Jr., MD, FACC; JIMMY F. HOWELL, MD, FACC; E. STANLEY CRAWFORD, MD, FACC; DON C. WUKASCH, MD; FRANK M. SANDIFORD, MD, Houston, Texas

To delineate further the efficacy of direct coronary artery surgery, the first 350 patients undergoing surgery have been analyzed for a period up to 3 years postoperatively. All these patients underwent 1 or more saphenous vein bypass grafts from the ascending aorta to the coronary arteries distal to the major occlusive disease. Patient selection was based on previous symptoms, history of myocardial infarction and cinearteriographic patterns of occlusive disease. Severity of these preoperative findings acted as an impetus to early surgery rather than a contraindication. Only acute ,myocardial infarction precluded immediate operative treatment. Over 70% of the patients were in functional classes III and IV, and 20% had overt congestive heart failure. The left ventricular end-diastolic pressure was increased in 48% of this group, Symptom duration ranged from 1 month to 20 years. Eighty-eight percent of the patients had more than 1 major vessel involved by selective coronary arteriograms. Total occlusion of a major vessel with no demonstrable distal runoff angiographically did not prohibit surgical repair. Despite lack of exclusion of a desperately ill group of patients, overall hospital mortality was Iess than 8% with 80% of the patients rendered symptom-free. Postoperative cinearteriograms, late mortality and duration of benefit have been correlated with the preoperative state. The improvements in technique, postoperative care and patient selection accounting for these good results will be discussed.

mals was 0 .103 second (SD t 0.008) ; in the patients with LBBB it was 0.159 second (SD 2 0.020), showing a significant delay of the carotid upstroke in those persons with LBBB (P O.lO). Although the origin of the jugular C wave cannot be stated with certainty, our findings militate against a carotid arterial origin. Pathologic Aspects of Idiopathic Hypertrophic Subaortic Stenosis with Particular Reference to the Mitral Valve WILLIAM C. ROBERTS, MD, FACC, Bethesda, Maryland

Relatively little anatomic information is available in patients with idiopathic hypertrophic subaortic stenosis (IHSS). Of 22 autopsy patients (aged 12 to 82 years [average 441) with IHSS, 13 of 19 catheterized had left ventricular (LV) to systemic arterial peak systolic pressure gradients from 8 to 155 mm Hg (average 65) ; 4 had systemic hypertension ; 5 atria1 fibrillation; and 5 complete bundle branch block. In contrast to the variable clinical manifestations, the cardiac anatomic features were nearly constant, although of various desepta in 21 patients were grees. The ventricular thicker than LV free walls; 21 had focally thickened mitral leaflets (6 presented clinically with pure mitral regurgitation) ; all had normal-sized or small LV cavities but dilated left atria. The aortic valve cusps were normal in all but 3 cases, in 2 of which they had fibromas; and 18 patients had thickened endocardial plaques in the LV outflow tract. Some thickening of the mitral leaflets appeared to result from constriction of the valves by the thick LV walls. The LV papillary muscles in 21 patients were focally scarred, but none were atrophied. Two older patients had calcified mitral annulas. The only anatomic feature present at birth in patients with IHSS appears to be disproportional ventricular septal hypertrophy. The other anatomic abnormalities appear to be acquired consequences of this basic abnormality.

The Origin of the Jugular C Wave LLOYD L. RICH, MD; MORTON E. TAVEL, MD, FACC, Indianapolis, Indiana

The origin of the jugular C wave has been disputed for over 100 years. If the jugular C wave were caused by carotid arterial interference as Mackenzie and Wood maintained, it would follow that in patients with left bundle branch block (LBBB) (in which it is known that carotid upstroke is delayed), the C wave would likewise be delayed. To test this hypothesis, 17 patients with complete LBBB and without aortic valvular disease were compared with 17 normal persons. Phonocardiograms were obtained in all 34 cases, and the following intervals were measured and compared between the 2 groups: R-R interval; Q-carotid upstroke and Q-jugular C wave. The R-R intervals were the same for the 2 groups, 0.84 second. The Q-carotid upstroke interval in nor-

656

Exercise Tests. A Survey of Procedure, Safety and Litigation Experience in Approximately 170,000 Tests PAUL ROCHMIS, MD; HENRY N. BLACKBURN, Washington, D. C. and Minneapolis, Minnesota

Jr., MD, FACC.

This survey reports experience from about 170,000 exercise tests from 73 centers. Several patterns emerged from a variety of procedures used: (1) A medical history, physical examination and resting electrocardiogram (ECG) were generally required before testing. (2) Recent or active cardiovascular disease or major disabilities were usually excluded. (3) Informed consent, more often verbal than written, was usually obtained. (4) Specific criteria of symptoms, signs and ECG findings were followed for termination of the test. (5) Progressive work loads were employed by the majority. (6) Thoroughgoing resuscitation facilities were

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