Results of 14 Years' Experience in the Surgical Treatment of Human Coronary Artery Insufficiency

Atherosclerosis obstructs the main stems of coronary arteries, restricting the coronary artery inflow tract. Nature develops intramyocardial collaterals but fails to form extracoronary collateral channels. It is only through surgical measures that extracoronary collateral channels may be formed, for example, by internal mammary artery implantation and omental graft without pedicle operations. Preoperative assessment, with particular reference to anginal pain, disease activity, indications for and contra-indications to surgery, is outlined. The importance of cine coronary arteriography is stressed. The results of internal mammary artery implantation with or without omental graft in patients followed up for two to 14 years are presented. Operative mortality in 103 consecutive patients was 2.9%. There was marked improvement in over 70% of 115 patients reviewed. Post-operative examination of 29 implanted internal mammary arteries showed that 76% were open when examined up to 10 years postoperatively; many of these were studied by cineangiography.     

A new method for the visualization of subepicardial coronary arteries in small isolated mammalian hearts

A model is described which permits direct visualization of large coronary arteries in a supported modified perfused heart preparation, using a perfluorochemical (FC-43) as perfusate. Filling of a large coronary artery with Patent Blue Dye is recorded by gated photography (color arteriography). The technique is applicable to the study of reactivity (spasm) of coronary arteries in hearts of small and large animals (rats, rabbits, dogs). The technique has the following advantages: preservation of vascular endothelium, adequate oxygenation, avoidance of major surgical intervention to implant sensors for the detection of changes in coronary diameter, quantitative evaluation of time dependent changes in geometry of large coronary arteries and simultaneous measurement of large coronary vessel and total coronary vascular resistance.     

Accelerated progression of coronary artery disease.

Atheromatous disease of the arteries is progressive and often results in untimely morbidity and premature death. The pathogenesis of the arterial lesion is as complex as its rate of progression is variable and ill understood. In six patients undergoing coronary arteriography, who were being restudied before percutaneous transluminal coronary angioplasty, the angiographic appearance deteriorated considerably over a fairly short period (mean 3.6 months). Although early detection and preventive measures have lowered the incidence of atheromatous disease and improved survival in some patients, rapid progression of the disease remains a serious hazard in others, who, as a group, remain at present unidentifiable.     

Combined Internal Mammary Artery Implantation and Free Omental Graft Operation: A Highly Effective Revascularization Procedure: (A Study of 17 Cases)

One hundred and forty patients with coronary artery disease treated by internal mammary artery implantation were followed up from six months to 13 years. The mortality rate was 3%; improvement was obtained in 70%. Occlusive disease of all three major coronary arteries, however, requires more blood than can be supplied by the implant procedure, and the free omental graft operation was developed for the management of selected patients with this condition. Normally in animals triple coronary artery ameroid constriction results in 100% mortality. When the free omental graft operation, with or without internal mammary artery implantation, was performed, 80% of such animals survived. The free omental graft forms capillary anastomoses in three days and arteriolar vessels in eight days, which leave the base of the aorta, enter the omentum, thence to the myocardium. A combined internal mammary artery implantation and free omental graft operation was performed in 17 patients with triple coronary artery disease as shown by cine coronary arteriography. There was no operative mortality, and 12 of the patients are free of pain and have returned to work.     

CORONARY ARTERIOGRAPHY

The rapid injection of opaque media through a large bore, closed-end, side-hole catheter positioned adjacent to the sinuses of Valsalva reliably opacifies the coronary arteries. The potential toxicity of a rapidly introduced large volume of contrast agent and the necessity of peripheral arteriotomy are drawbacks of this procedure.Such innovations as loop-ended catheters, balloon occlusion of the aorta, percutaneous arterial catheterization and acetylcholine cardiac arrest have been introduced as attempts are made to increase the reliability and safety of coronary arteriography.     

Reassessment of failed beta-blocker treatment in angina pectoris by peak-exercise heart rate measurements.

Twenty-one patients with angina pectoris were treated with adrenergic beta-receptor antagonists. Previously the resting heart rate had been used as a guide to treatment, a reduction in the rate to 55-60 beats/min without symptomatic improvement indicating failure of medical treatment. These patients were re-evaluated before coronary arteriography using the peak-exercise heart rate as an index of adrenergic beta-receptor antagonism. The dose of beta-blocking drugs was increased to produce a peak-exercise heart rate of less than 100 beats/min or a consistent rate of 100-125 beats/min which would not lessen in spite of progressive dose increments. The resting heart rate was ignored. On these criteria 15 patients previously considered to have responded inadequately to beta-blockade responded satisfactorily and were therefore removed from the waiting list for coronary arteriography. They all remained well up to two years later. Six patients failed to respond and had coronary arteriography with a view to surgical treatment. Reliance on the resting heart rate as the index of optimum adrenergic beta-receptor antagonism is likely to lead to premature or unnecessary referral for surgery; the failure of beta-blockade in the treatment of angina pectoris can be determined simply and accurately by using peak-exercise heart rate.     

Cocaine: its use in otolaryngology

A review of 120 patients who had a discharge diagnosis of intermediate coronary syndrome showed 12 patients with documented transient ST elevation during spontaneous rest pain consistent with Prinzmetal''s angina. Coronary arteriography showed severe proximal occlusive coronary atherosclerosis in nine of the patients, and normal or minimal disease in the other three patients. In two of these three, there was documented coronary arterial spasm with reproduction of symptoms during arteriography. Although a shorter history of chest pain, presence of an old myocardial infarction and a positive finding on electrocardiogram treadmill test tended to predict the patients with severe occlusive coronary artery disease, these methods were inadequate to select candidates for arteriography. All patients responded well to nitroglycerine while in the hospital. Five of the nine patients with coronary artery disease had coronary bypass operations, with two excellent, two fair and one poor result. One of the three patients with normal findings on coronary arteriograms died with refractory ventricular arrhythmia six months after study. The other two have had good-to-moderate relief of symptoms on long-acting vasodilators and propranolol. Current concepts of the syndrome of Prinzmetal''s angina and ST elevation are reviewed. It appears that this syndrome has a wide spectrum of clinical presentations and coronary arteriographic anatomies.     

The Pathogenesis of Human Myocardial Infarction

Coronary arteriography, dissection of the coronary arteries and histopathological examination of the heart were carried out in 150 autopsies to study the effect of coronary narrowing and occlusion, of the presence of collaterals, and of coronary artery predominance on the development of myocardial infarction. The thrombosis rate was related to the severity of coronary sclerosis. The development of collaterals was not enhanced by coronary sclerosis and occlusion, and collaterals did not protect the myocardium against reinfarction. Coronary occlusion was regularly demonstrable in recent myocardial infarct cases. The association of atrial and posterior ventricular infarcts was explained by occlusion of their common arterial branch. The interdependence between coronary sclerosis, thrombosis and myocardial infarction in human autopsy material emphasizes the importance of mural coronary artery disease in the genesis of coronary occlusion and myocardial infarction, and it is at variance with statistical data and experimental results.     

ORTHOSTATIC RENAL ARTERIOGRAPHY

Orthostatic renal arteriography has served to provide better delineation of the renal arteries, to better define stenotic lesions of these vessels and to point to a possible relationship between excessive renal mobility and the development of mural hyperplasias of the renal artery. It is suggested that where facilities permit, orthostatic renal arteriography be employed as a method of obtaining a better understanding of renal artery architecture and function in patients who are being studied for secondary hypertension.     

Myocardial perfusion imaging with thallium-201: correlation with coronary arteriography and electrocardiography

Myocardial perfusion imaging with thallium-201 and electrocardiography with the subject at rest and undergoing submaximal treadmill exercise were performed in 19 men and 3 women. Selective coronary arteriography and left ventriculography showed that 7 had normal coronary arteries and 15 had coronary artery disease.The 11 persons with electrocardiographic evidence of an old myocardial infarct (q waves) had a perfusion defect at rest in the area of the infarct and a segmental abnormality of wall motion apparent on the left ventriculogram corresponding to the perfusion defect.Myocardial perfusion imaging and electrocardiography were equally sensitive in detecting coronary artery disease in exercising individuals: perfusion defects were noted in 7 of the 15 persons with coronary artery disease, and diagnostic ST-segment depression was present in 8 of the 15. Combination of the results of the two tests with exercise permitted the identification of 11 of the 15 persons and improved the sensitivity. Combination of the results of rest and exercise imaging and electrocardiography permitted the identification of 94% of the patients with coronary artery disease.Myocardial perfusion imaging with ²⁰¹TI in the subject at rest is a sensitive indicator of previous myocardial infarction. Imaging after the subject has exercised is a useful adjunct to conventional exercise electrocardiography, especially in those whose exercise electrocardiogram is non-interpretable.     

Anatomical correction of complete transposition of the great arteries and ventricular septal defect in infancy.

Two patients, aged 8 weeks and 5 years, with D transposition of great arteries and large ventricular septal defect were treated by transection of both aorta and pulmonary arteries and reattaching them to the appropriate ventricles. This included the origins of the coronary arteries. The ventricular septal defect was closed through a transverse ventriculotomy using a Dacron patch. The younger child was operated on as an emergency because of cyanosis and severe heart failure resistant to intensive medical treatment. The older child had had previous banding of the pulmonary artery at the age of 1 year. In both patients pulmonary artery pressure dropped to below half systemic pressure immediately after the operation. Postoperative progress was satisfactory with relief of cyanosis and heart failure. Early anatomical correction of transposition of the great arteries and ventricular septal defect is feasible and should play an important part in the management of these patients.     

Different accumulation of elements in the rami of the coronary arteries of Thai

To analyze the accumulation of elements in the rami of the coronary arteries, the authors determined element contents in both the coronary arteries and their rami of the Thai by inductively coupled plasma-atomic emission spectrometry. The subjects consisted of 13 men and 6 women, ranging in age from 34 to 83 yr. It was found that a higher accumulation of calcium and phosphorus occurred in the proximal sites of coronary arteries such as the anterior descending, right coronary, left coronary, and circumflex arteries than the distal sites such as the diagonal, lateral, conus, acute marginal, and posterior descending arteries. The accumulation of calcium and phosphorus in the anterior descending and right coronary arteries of the Thai increased remarkably in the fifties, thereafter decreased, and increased again in the eighties. It should be noted that a very high accumulation of calcium and phosphorus in the coronary arteries occurred in the fifties. In regard to relationships among the average contents of elements in the coronary arteries and their rami, it was found that there were very significant direct correlations between calcium and phosphorus contents, between calcium and magnesium contents, and between phosphorus and magnesium contents. These results suggested that as calcium and phosphorus increased in the coronary arteries and their rami, magnesium increased simultaneously in all of the coronary arteries and their rami.     

Identification of [I]endothelin binding sites in human coronary tissue

In vitro receptor autoradiography has been used to study the distribution of [¹²⁵I]endothelin binding sites in human coronary tissue from patients undergoing cardiac transplantation. Dense binding of [¹²⁵I]endothelin was associated with the smooth muscle of epicardial coronary arteries as well as to perivascular regions of these vessels. Binding was also associated with the ventricular myocardium. There was an increased binding of [¹²⁵I]endothelin to atheromatous tissue, both coronary arteries and vein graft.

The [¹²⁵I]endothelin binding sites identified using in vitro autoradiography are likely to be functionally relevant since endothelin causes a concentration-dependent contraction of segments of human epicardial coronary arteries in vitro and also has positive inotropic activity on isolated human cardiomyocytes.

The presence of specific binding sites for [¹²⁵I]endothelin on coronary tissue and the increased binding in atheromatous tissue suggest that endothelin is a peptide which may play a role in the maintenance of vascular tone and/or the pathogenesis of ischaemic heart disease.     

Glutathione attenuates coronary constriction to acetylcholine in patients with coronary spastic angina

This study examined the effect of reduced glutathione (GSH), an important antioxidant that restores intracellular redox imbalance and prevents inactivation of endothelial-derived nitric oxide, on the abnormal vasomotor reactivity in spastic coronary arteries. The responses of epicardial diameter of the left coronary arteries to intracoronary infusion of acetylcholine (ACh; 50 microg/min) were measured by quantitative coronary angiography before and during combined intracoronary infusion of GSH (50 mg/min for 6 min) or saline as a placebo in 24 patients with coronary spastic angina and in 28 control patients. All of the spastic coronary arteries showed constrictor response to ACh, whereas the control coronary arteries as a whole showed only minimal diameter changes to ACh. GSH infusion suppressed constrictor response of epicardial diameter to ACh in patients with coronary spastic angina, whereas it had no significant effect in control subjects. Saline infusion did not have any effects. The results indicate that GSH attenuated the constrictor response to ACh in epicardial coronary arteries of patients with coronary spastic angina. GSH may have an important role in the regulation of coronary vasomotor function in patients with coronary spastic angina.     

Early exercise testing after treatment with thrombolytic drugs for acute myocardial infarction: importance of reciprocal ST segment depression.

OBJECTIVE--To investigate the clinical importance of reciprocal ST depression induced by exercise testing early after acute myocardial infarction in patients treated with thrombolysis. DESIGN--Prospective observational study. SETTING--District general hospital in London. SUBJECTS--202 patients (170 men) aged 33-69 with acute myocardial infarction treated with thrombolysis. MAIN OUTCOME MEASURES--All patients underwent exercise testing and coronary arteriography. ST depression induced by exercise was classified as either reciprocal (associated with ST elevation) or isolated (occurring on its own). The relation between reciprocal ST depression and the following end points was studied: characteristics of the infarct, left ventricular ejection fraction, extent of coronary artery disease on arteriography, and presence of angina induced by exercise. RESULTS--Reciprocal ST depression occurred almost exclusively in Q wave infarctions and was associated with a lower overall ejection fraction than isolated ST depression. It tended to be associated with persistent occlusion of the coronary artery related to the infarct and did not indicate remote ischaemia due to multivessel coronary disease. Unlike isolated ST depression, reciprocal ST depression was not associated with angina induced by exercise. CONCLUSIONS--Reciprocal ST depression induced by exercise is usually associated with extensive Q wave infarctions and persistent occlusion of the artery related to the infarct. It does not seem to indicate reversible ischaemia and should not be used as a non-invasive marker of multivessel disease in the assessment of requirements for further investigation soon after acute myocardial infarction.     

Global revascularization: the role of the cardiologist

There are compelling reasons for cardiologists to undertake a more global approach to patients with peripheral vascular diseases: atherosclerosis is a 'systemic' disease frequently causing both coronary and peripheral vascular problems in the same patient; coronary artery disease is the most common cause of morbidity and mortality in patients with peripheral vascular disease; and peripheral vascular disease negatively impacts the management of angina pectoris and congestive heart failure. There are four major areas of special interest to the cardiologist: (1) iliac arteries (vascular access), (2) renal arteries (hypertension and volume overload), (3) subclavian arteries (coronary steal with a left internal mammary artery [LIMA] graft), and (4) carotid arteries (stroke). Technical skills necessary to perform coronary angioplasty are transferable to the peripheral vasculature. However, an understanding of the natural history of peripheral disease, patient and lesion selection criteria, and knowledge of other treatment alternatives are essential to performing these procedures safely and effectively. Appropriate preparation and training, and a team approach, including an experienced vascular surgeon, are both desirable and necessary before interventional cardiologists who are inexperienced in the treatment of peripheral vascular disease attempt percutaneous peripheral angioplasty. There are inherent advantages for patients when the cardiologist performing the procedure is also a clinician. Judgments regarding the indications, timing, and risk/benefit ratio of procedures are enhanced by a long-term relationship between physician and patient. Finally, in view of the increased incidence of coronary artery disease in patients with atherosclerotic peripheral vascular disease, the participation of a cardiologist in their care seems appropriate.     

The atrioventricular branches of the human coronary arteries

Branches of the coronary arteries of normal human hearts, supplying both atria and ventricles, were found by fine dissection and have been named rami atrioventriculares. They comprise atrial branches from ventricular arteries and ventricular branches from atrial arteries. Their incidence was 74% in the 50 adult individuals studied. The subjects had committed suicide with a poison which did not damage the coronary arteries. The atrioventricular branches constitute communications across the coronary sulcus, thus establishing a continuity between the atrial and the ventricular arterial supply. Therefore, there is not invariably a sharp demarcation of blood supply between atria and ventricles, as has been commonly taught. Neither atrial nor ventricular branches consist exclusively of ascending and descending branches of the coronary arteries, as has been assumed. Atrioventricular branches can play a role in collateral circulation and may, in individuals who are born with them, provide an explanation for some of the variability in signs and symptoms incidental to heart attacks.     

Duplex scanning of brachiocephalic arteries and multislice spiral computed tomography of coronary arteries in the comprehensive evaluation of the arteries in women with rheumatoid arthritis

Comprehensive examination was made in women (mean age 49.6 +/- 7.4 years) with rheumatoid arthritis diagnosed abnormalities of brachiocephalic and coronary arteries in 86% of cases. Duplex scanning of brachiocephalic arteries revealed changes in 82% of the women. 64-section spiral computed tomography established coronary artery abnormalities in 33% of cases. There were isolated changes in the brachiocephalic arteries in 50% of the patients, a concomitant lesion of the brachiocephalic and coronary arteries in 32%, and isolated changes in the coronary arteries in 4%. A direct correlation was found between the index of coronary artery calcification and the intima-media thickness of brachiocephalic arteries.     

Coronary artery reactivity in human vessels: some questions and some answers

Spasm of a conduit coronary artery, converting it into a major resistance vessel impeding myocardial blood flow, may have severe short- or long-term effects on cardiac rhythm and systolic ejection of blood. It is now clear that human coronary arteries in vitro contract to acetylcholine but that relaxation is the only response observed in dog coronary vessels. Acetylcholine is as powerful a constrictor of human coronary arteries, in terms of tension induced, as 5-hydroxytryptamine (5-HT) or histamine and is a substantially more powerful constrictor than norepinephrine. Field stimulation of coronary artery strips caused a vasoconstriction that was partially antagonized by atropine (3.45 X 10(-6) M). An enhanced reactivity of the epicardial arteries of cardiac and older patients to several agonists was also observed and appears to provide a background against which a number of vasoactive agents might induce spasm. Coronary tissue from cardiac patients also contains stores of 5-HT and histamine, and the histamine levels are substantially increased above the values in vessels from noncardiac patients. Coronary artery spasm or contraction probably can be initiated by diverse intrinsic and extrinsic influences, including autonomic discharge from either the parasympathetic or sympathetic nervous system or from histamine or 5-HT, and probably no one agent or entity is causative in all cases.