ABSTRACTS

SURGICAL RELIEF OF MYOCARDIAL ISCHEMIA DUE TO MYOCARDIAL BRIDGES Albert E. Raizner, MD, FACC; Tetsuo Ishimori, MD, FACC; Mario S. Verani, MD, FACC; William H. Spencer, MD, FACC; Gene Guinn, MD, FACC; Robert A. Chahine, MD, FACC; Jimmy F. Howell, MD, FACC; Richard R. Miller, MD, FACC, Baylor College of Medicine, Houston, Texas. Myocardial bridges (MB) have long been suspected of causing ischemia in man. However, firm documentation of ischemia secondary to MB has been lacking. We studied 9 patients (pts), 8 male, 1 female, whose ages ranged from 28 to 66 (mean = 46) years, with MB which produced > 50% systolic narrowing of the coronary artery (CA). Two pts had transmural anterior myocardial infarction which was precipitated by heavy exertion and documented by electrocardiography and enzymes. Both had MB of the anterior descending (LAD) but otherwise normal CA. In the remaining 7 patients, myocardial ischemia was docu- mented by treadmill exercise testing (TET) and exercise scintigrams (ESG) with thallium-201. TET was positive (ST depression > 1 mm) in 6 of 7 pts. ESG showed rever- sible hypoperfusion during exercise in the myocardial region supplied by the bridged artery in all 7 pts. Four of 7 had anterior perfusion defects with LAD MB. Three pts had anterior and inferior defects: One of these had LAD and right CA MB; 2 had LAD MB and coexistent fixed right CA stenosis. Surgical interruption of the MB was performed in 3 patients because of persistent angina, one of who had bypass to the right CA. Each had complete re- lief of symptoms and post-operative ESG and TET reverted to normal. Thus, myocardial ischemia and myocardial in- farction secondary to MB can be firmly documented in some pts. Surgical interruption of the MB should be con- sidered in pts with refractory symptoms that can be clearly attributed to the MB.

HEMODYNAMIC EFFECTS OF INTACT HUMAh' PERICARDIUM AFTER CORONARY BYPASS SURGERY. Richard Jamshid Maddahi. M.D.. Mariorie Ravmond. R.N.. Daniel Berman, M.D., ’ ’ -

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FACC, Hector Sustaita, M.D. and Jack Matloff, M.D., FACC. Cedars-Sinai Medical Center, Los Angeles, California.

Because little is known about the cardiac effects of normal human pericardium, 36 patients (pts) had hemo- dynamic measurements with multiple gated equilibrium cardiac blood pool scintigraphy in a subgroup of 29 pts before, early (l-6 hours) and 2 days after coronary by- pass surgery. Surgery included moderate hypothermia (mean temperature 2300 and techniques designed to avoid pericardial drying and shrinkage. The pericardium was left open in 25 pts (Group A), and closed in 11 (Group B). No differences in age, preoperative left ventricular func- tion, number of vessels diseased or grafted, total pump or ischemic times or degree of hypothermia were detected be- tween groups. No pt had cardiac tamponade. Compared to Group A, Group B pts had higher right atria1 (12 f 3 vs 9 f 3. mean f S.D.), pulmonary capillary wedge (14 f 4 vs 11 f 4) and mean pulmonary arterial pressures (21 f 3 vs 18 i 4 mmHg), total pulmonary resistance (464 i 140 vs 339 f 95 dyne.sec*cm-5) and lower cardiac index (1.9 f .5 vs 2.3 f .3 L/m/m2) (all pc.05) immediately and on post- operative day 2. No differences were noted in postopera- tive heart rate, arterial pressure, systemic vascular resistance, and right or left ventricular ejection frac- tion by scintigraphy. Thus with intact pericardium after coronary bypass surgery: 1) an adverse effect on cardiac performance is seen through postoperative day 2; and 2) diminished cardiac output in spite of higher atria1 pres- sures suggests either diminished overall'cardiac compli- ance or an altered Starling function relationship.

TREATMENT OF ANTERIOR TRANSMURAL MYOCARDIAL INFARCTION IN MAN WITH AND WITHOUT EARLY REPERFUSION Marcus A. DeWood, MD; Julie Spores; Henry T. Lang, MD; John H. Ganji, MD; Ken I. Sutherland, MD, FACC; William P. O'Grady, MD, FACC, Sacred Heart and Deaconess Medical Centers, Spokane, Washington.

Anterior wall myocardial infarction (MI) is associated with high mortality. The role of early reperfusion for anterior MI with coronary artery bypass grafting (CABG) is uncertain. Ninety-five patients (pts) (mean age ? SD = 52.8 z 7.2 years) with anterior MI (Group I) were admitted within 24 hours of symptoms and managed conventionally for anterior MI. During the same time period (6/72-12/76) 97 pts (Group II) (age - 53.6 + 8.1 years) were admitted for anterior MI but were evaluated with early coronary arteri- ography and treated with CABG. All patients in both groups had chest pain, persistent ST elevation >3 mm pro- gressive to Q waves, and evolved creatine kin& eleva- tion. Pts with identifiable coronary spasm, diffuse dis- tal disease of coronary artery and pts considered too ill to withstand CABG were exluded from this study. In-hos- pital mortality (IHM) and long-term mortality (LTM) (30- 68 months) were evaluated.

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IHM LTM (30-68 months) Group I Group II

15.7% (15/95) 28.4% (27/95) 4.1% ( 4/97)pc.03 11.3% (11/97)p<.Ol

When patients with shock (i.e., BP less than 85 mm Hg, left ventricular filling pressure greater than 18 mm Hg and hypoperfusion) were excluded, the in-hospital mor- tality for Group II was 1.1% (l/88). These observations in concurrent groups suggest early reperfusion for evolv- ing anterior myocardial infarction may be helpful in reduction of in-hospital mortality and long-term mortality in selected patients.

RESECTION OF VENTRICULAR ANEURYSM MODIFIED BY ELECTRO- PHYSIOLOGIC ASSESSMENT IN PATIENTS WITH INTRACTABLE VENTRICULAR TACHYCARDIA AND LEFT VENTRICULAR ANEURYSM William B. Allen, MD; James D. Maloney, MD, FACC; Geoffrey 0. Hartzler, MD: David R. Holmes. Jr.. MD. FACC: , , Francisco J. Puga, Mb, Mayo Clinic and Mayo Foundation, Rochester, Minnesota

Patients (pts) with left ventricular aneurysm (LVA) com- plicated by recurrent ventricular tachycardia (RVT) have a poor prognosis with current medical therapy, standard LVA resection and/or revascularization. Recent reports suggest. that extensive LVA resection, subendocardial ex- cision, or encircling endocardial ventriculotomy may be more effective in interruption of the RVT mechanism. The importance of preoperative and intraoperative RVT induc- tion, epicardial and endocardial mapping, and assessment of residual myocardial function remain uncertain. Observations related to 15 pts with LVA-RVT undergoing surgical resection or isolation of LVA utilizing preop- erative and intraoperative electrophysiologic data are reported. Epicardial (12 pts) plus endocardial mapping (3 pts) were performed. Extensive LVA resection modified by mapping data were performed in 13 pts. Five of 13 pts had resection of a portion of the septum and right ven- tricle. One of 13 pts had LVA resection plus encircling ventriculotomy; 2 pts had LVA plication. Eight of 15 pts had revascularization. Two pts died in the early postoperative period, one with RVT. All survivors were improved hemodynamically with a mean follow-up of 19 months (range 2 to 40). Spontaneous RVT has been observed or suspected in only one patient. Excision or isolation of LVA ischemic margins appear important. Preoperative and intraoperative electrophysi- ologic assessment appears advantageous in patient selec- tion and designing surgical intervention.

February 1980 The American Journal of CARDIOLOGY Volume 45 417