Parry B. Larsen

Twelve-year experience with bilateral internal mammary artery grafts.

A 12 1/2-year experience with 227 patients who underwent coronary revascularization with bilateral internal mammary artery (IMA) and supplemental saphenous vein grafts is presented. There were 725 coronary grafts performed (3.2 per patient). Forty-four IMA grafts were sequential. In 42 patients, the right IMA was placed through the transverse sinus to revascularize the circumflex artery. Operative mortality was 4% (9 of 227 patients). Postoperative complications included sternal infection (4 patients), reexploration for bleeding (5), and diaphragmatic dysfunction (10). Postoperative arteriography in 30 patients (mean interval, 4 1/4 years) revealed that 92% (34/37) of the left IMA and 87% (26/30) of the right IMA grafts were patent. Late follow-up was complete in 207 surviving patients. Eighteen late deaths (9 cardiac and 9 noncardiac) occurred. Actuarial survival was 83% at 10 years after operation. Of 68 patients followed from 8 to 12 1/2 years (mean interval, 10 1/2 years), 69% were asymptomatic, and 28% were in New York Heart Association Functional Class II. We conclude that bilateral IMA grafting can be accomplished with low operative risk and provides excellent long-term results.

Bilateral internal mammary artery grafts in reoperative and primary coronary bypass surgery

Bilateral internal mammary artery grafting is recognized as a preferred method of myocardial revascularization. However, its efficacy in coronary bypass reoperation has not been clearly established. From January 1982 through June 1989, 88 patients underwent coronary bypass reoperation with bilateral internal mammary artery grafts. Results were compared with those for a subset of 88 patients receiving primary revascularization with bilateral internal mammary artery grafts who were computer matched for sex, age, left ventricular function, anginal classification, and left main coronary artery disease. In each group, 62.5% (55 patients) had unstable angina, 43.2% (38 patients) had reduced ejection fraction, and 21.6% (19 patients) in the reoperation group and 20.5% (18 patients) in the reference group had left main coronary artery disease. Hospital mortality for the reoperation group was 6.8% (6 patients) and for the reference group, 3.4% (3 patients). No significant difference was found in the incidence of reoperation for bleeding, sternal infection, or stroke in the two groups. The incidence of respiratory insufficiency in the reoperation group was 13.6% (12 patients) and in the reference group, 3.4% (3 patients) (p less than 0.015). Recurrent angina occurred in 13.7% (10 patients) of patients in the reoperation group and 13.3% (10 patients) in the reference group. The long-term survival at 5 years for the reoperation group was 85.3% +/- 5.6% (+/- standard error of the mean) and for the reference group, 91.6% +/- 3.1%. No significant difference was found in the equality of survival distribution for the two groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Sodium nitroprusside as a coronary vasodilator in man. I. Effect of intracoronary sodium nitroprusside on coronary arteries, angina pectoris, and coronary blood flow.

Summary The effect of the intra-arterial injection of 5 to 10 μg of sodium nitroprusside on the caliber of normal and diseased coronary arteries was evaluated in 21 patients during diagnostic cardiac catheterization. In addition, the effect of intragraft injection of 5 μg of the same agent on the blood flow in aorta-right coronary artery saphenous vein bypass grafts was also evaluated intra-operatively in two patients. The compound induced an increase in the caliber of both normal and stenosed coronary arteries as well as an increase of flow in the grafts. Consistent with measurements of coronary flow response to sodium nitroprusside, angina pectoris which developed in four patients during cardiac catheterization was immediately relieved and the ischemic ST-segment depression significantly reversed after injection of 5 to 10 μg of the drug into the left main coronary artery. Within the dose range used, the drug caused no significant effect on systemic blood pressure or apparently deleterious electrophysiologic changes. No side effects were observed. We conclude that the primary direct action of sodium nitroprusside in the human coronary artery is vasodilatory.

Leaf movement in Calathea lutea (Marantaceae)

SummaryCalathea lutea is a broad-leaved, secondary successional plant which shows complex leaf movements involving both elevation and folding of the leaf surface about the pulvinus. In the plants studied, mean leaf elevation increased from approximately 34 degrees in the early morning to 70 degrees at noon while the angle of leaf folding increased from 13 degrees to 50 degrees over the same time period. During the period from early morning to noon, these movements resulted in a significant decrease in the cosine of the angle of incidence, a measure of the direct solar radiation intercepted. The observed changes in elevational angle significantly reduce the cosine of angle of incidence while folding does not significantly reduce the fraction of direct solar radiation intercepted during the period of direct exposure of the leaf surface to the solar beam. Since elevational changes seem to account for the reduction in exposure to direct solar radiation, the role of folding remains unclear.

Bilateral Internal Mammary Artery Grafts in Patients with Left Main Coronary Artery Disease

The use of the internal mammary artery (IMA) in myocardial revascularization has been expanded with bilateral and sequential grafting. However, its application in the presence of left main coronary artery stenosis (LMCAS) has not been well established. From September 1983 through December 1990, 280 patients with LMCAS greater than 50% were revascularized (3.4 mean grafts per patient) with bilateral IMA and saphenous vein grafts. Eighty‐one were sequential IMA grafts. There were 234 males (83.6%) and 46 females (16.4%) with a mean age of 64.4 years (range 39 to 84 years). Preoperatively, there were six patients (2.1%) in New York Heart Association (NYHA) Class I, 30 patients (10.7%) in Class II, 130 patients (46.4%) in Class III, and 114 patients (40.7%) in Class IV. Fifty‐six patients (20.0%) had an ejection fraction less than 50%. In‐traaortic balloon counterpulsation was used preoperatively in 26 patients (9.3%) and intraoperatively in 11 patients (3.9%). There were four hospital deaths (1.4%). Hospital complications included: reoperation for bleeding, 7 patients (2.5%); pulmonary insufficiency, 21 patients (7.5%); perioperative infarction, 14 patients (5.0%); and stroke, 4 patients (1.4%). Follow‐up was obtained in 276 hospital survivors (100.0%) with a mean of 33.4 months. There were 20 late deaths (7.1%): seven cardiac related and 12 noncardiac related. Postoperative assessment reveals substantial functional improvement. These results furnish evidence that bilateral IMA grafts can be accomplished with a low operative risk and can provide excellent functional results in patients with LMCAS.

Solitary Pulmonary Lesion Due to Dirofilaria

TO the etiology of solitary pulmonary nodules dirofilarial infestation with pulmonary infarction has recently been added. Ten cases have been reported to date.1 2 3 We have encountered two patients...

Surgical Management of the Preinfarction Syndrome

Abstract The indications for coronary reconstruction have been extended to include those patients with the preinfarction syndrome who have failed to respond to medical therapy. Preinfarction syndrome is characterized by: (1) rapidly progressive angina; (2) exacerbation of previously stable angina; and (3) recurrent bouts of coronary insufficiency. During a three-year period 60 patients with this syndrome ranging in age between 30 and 72 years underwent urgent or emergency bypass procedures. Twenty showed electrocardiographic evidence of previous myocardial infarction. Single-vessel disease (> 75% obstruction) was demonstrated by coronary angiography in 18, double-vessel disease in 14, and triple-vessel involvement in 28. The operative technique is described. Eight sustained an early and 5 a late myocardial infarction with 1 and 3 deaths, respectively. A detailed analysis of these patients is presented including restudies and pathological findings. Of the 56 survivors, only 2 continue to have incapacitating angina. From this experience we conclude that the surgical management of a selected group of patients with the preinfarction syndrome is associated with a lower mortality and an improved functional result when compared with the natural history of the syndrome.

Coronary Heart Disease

Coronary heart disease (CHD) is the comprehensive term which includes all of the clinical manifestations that result from atherosclerotic1 narrowing or occlusion of the arteries which supply the heart muscle. The hallmark of clinically manifest atherosclerosis is the progressive deposition of cholesterol as plaques in artery walls. Eventually this leads to secondary changes. Fibrous scar tissue and calcium may accumulate (hence the “hardening”), or the plaques may become necrotic and abscess-like if they outstrip their blood supply. Then hemorrhage into the softened plaque may result in rapid increase in lesion size or the contents may erupt to the surface. If the bloodstream interface of the deposit breaks down, large pieces of cholesterol debris may flake off into the circulation, occluding vessels downstream, and there may be thrombus2 formation on the rough ulcer surface. When thrombosis occurs in coronary arteries the thrombus usually totally occludes the vessel, producing a myocardial infarction.3