Distal Coronary Artery Segments Research Articles

Early and late results of coronary artery bypass in patients with hyperlipoproteinemia

Hyperlipoproteinemia is a known risk factor for the development of coronary artery disease. To assess the perioperative and late results of myocardial revascularization for angina pectoris in patients with hyperlipoproteinemia, we reviewed the records of 200 patients (age range 24 to 75 years). Preoperatively the average New York Heart Association (N.Y.H.A.) angina class was 3.1 ± 0.7. One hundred three patients (51.5%) had type 11 disease, 95 patients (47.5%) type IV, and two (1%) had type III or V disease. The mean age of the patients with type II disease was 3 years less than that of patients with type IV disease (50 versus 53 years, p < 0.05). When compared with subjects with type IV disease, those with type II disease were shown by angiography to have a significantly higher incidence of left main coronary artery stenosis (28% versus 6%), a greater average number of proximal coronary artery lesions per patient (2.8 ± 0.9 versus 2.4 ± 0.7), and more frequent atheromatous disease in distal coronary artery segments (74% versus 49%) (all p <0.01). The operative mortality rate of coronary revascularization was 6% (12/200), including nine patients with type II disease (9.5%) and three with type IV disease (2.9%). All deaths occurred in patients with three- and four-vessel coronary artery disease. Seven (58%) of these 12 patients had left main coronary artery disease and 10 (83%) had significant distal lesions. The nonfatal perioperative infarct rate was 4%. At a mean follow-up period of 33 months (range 10 to 90 months), there have been four late deaths (2.2%), including three patients with type II disease (3.5%) and one with type IV disease (1.0%). There have been nine late nonfatal myocardial infarctions (4.9%). One hundred thirty-nine patients (73%) have had complete relief of angina and 34 (19%) have had substantial improvement. The average postoperative N.Y.H.A. class was similar for the two groups (1.6 ±0.7). Myocardial revascularization can be accomplished with acceptable risk and excellent long-term results in patients with hyperlipoproteinemia. However, patients with type II disease have higher hospital and late mortality rates. These findings are consistent with the known increased prevalence of left main coronary stenosis and diffuse distal coronary artery disease in patients with this type of hyperlipidemia.

Coronary collateral function in patients without occlusive coronary artery disease.

Little is known of the functional capacity of coronary collaterals in humans without occlusive coronary artery disease. We, therefore, measured peripheral coronary pressure (PCP) and retrograde flow (RF) from coronary arteries at aortic valve replacement in seven patients without occlusive coronary artery disease. Using a T-connection interposed in left (LCA) and right (RCA) coronary perfusion lines, data were obtained during brief proximal occlusion of each line. PCP was expressed as a fraction of perfusion pressure (PP), and collateral resistance (CR) was calculated as PP/RF. Median values were as follows: (a table was included). In contrast, previous studies of well-collateralized distal segments of diseased coronary arteries revealed mean RF 15.7, CR 5.1 and PCP/PP 0.50. Under the conditions of study, all vessels interconnecting the non-diseased RCA and LCA delivered flow and pressure less readily than collaterals to a single distal segment of a diseased coronary artery. Thus, collaterals in patients without diseased coronary arteries have an extremely limited capacity to transmit either flow or pressure. The absolute values of RF were small relative to the muscle mass perfused by each coronary artery, suggesting that perfusion of only one coronary artery in man during operation may not provide substantial perfusion for large portions of myocardium. Comparison of performance of collaterals supplying atherosclerotic and nonatherosclerotic coronary arteries indicates that proximal occlusion may be an important factor stimulating enhancement of collateral function. Moreover, the nitroglycerin-induced improvement in collateral function seen in patients with chronic occlusive coronary disease was not demonstrable in patients without coronary occlusion. Thus, coronary collaterals may acquire nitroglycerin responsiveness as a result of changes induced by chronic coronary occlusion.

Angulated views in the sagittal plane for improved accuracy of cinecoronary angiography.

ANGULATED VIEWS IN THE SAGITTAL PLANE FOR IMPROVED ACCURACY OF CINECORONARY ANGIOGRAPHYJACQUES LESPÉRANCE, M.D., JACQUES SALTIEL, M.D., ROBERT PETITCLERC, M.D. and MARTIAL G. BOURASSA, M.D.Audio Available | Share

Coronary collateral function in patients without occlusive coronary artery disease

Little is known of the functional capacity of coronary collaterals in humans without occlusive coronary artery disease. We, therefore, measured peripheral coronary pressure (PCP) and retrograde flow (RF) from coronary arteries at aortic valve replacement in seven patients without occlusive coronary artery disease. Using a T-connection interposed in left (LCA) and right (RCA) coronary perfusion lines, data were obtained during brief proximal occlusion of each line. PCP was expressed as a fraction of perfusion pressure (PP), and collateral resistance (CR) was calculated as PP/RF. Median values were as follows: (a table was included). In contrast, previous studies of well-collateralized distal segments of diseased coronary arteries revealed mean RF 15.7, CR 5.1 and PCP/PP 0.50. Under the conditions of study, all vessels interconnecting the non-diseased RCA and LCA delivered flow and pressure less readily than collaterals to a single distal segment of a diseased coronary artery. Thus, collaterals in patients without diseased coronary arteries have an extremely limited capacity to transmit either flow or pressure. The absolute values of RF were small relative to the muscle mass perfused by each coronary artery, suggesting that perfusion of only one coronary artery in man during operation may not provide substantial perfusion for large portions of myocardium. Comparison of performance of collaterals supplying atherosclerotic and nonatherosclerotic coronary arteries indicates that proximal occlusion may be an important factor stimulating enhancement of collateral function. Moreover, the nitroglycerin-induced improvement in collateral function seen in patients with chronic occlusive coronary disease was not demonstrable in patients without coronary occlusion. Thus, coronary collaterals may acquire nitroglycerin responsiveness as a result of changes induced by chronic coronary occlusion.

The patency and luminal diameter of distal coronary arteries in fatal, acute myocardial infarction.

This study was designed to evaluate the feasibility of performing aorto-coronary vein bypasses in patients dying with large, acute myocardial infarcts. The postmortem luminal diameters of distal segments of coronary arteries were measured in 40 such hearts. The measurements were taken in the distal right coronary artery, middle third of left anterior descending artery, and marginal branch of the left circumflex coronary artery (common sites for aorto-coronary vein bypass). In addition, five other alternate sites were similarly evaluated. Ninety-six percent (38) of all potential anastomotic sites were patent. The common sites of aorto-coronary vein bypass were patent in 93% (37). The luminal diameter of the artery supplying the fatal myocardial infarction, at the site of possible aorto-coronary vein bypass, was patent and suitable for bypass grafts in 95% (38) of 40 hearts studied.