Exercise-induced U-wave inversion as a marker of stenosis of the left anterior descending coronary artery.

The prevalence and cineangiographic correlates of exercise-induced inversion of U waves were studied in 248 patients. Exercise-induced U-wave inversion was observed in 36 patients (15%), of whom 35 had greater than or equal to 75% stenosis in one or more of the major coronary arteries. The proximal left anterior descending or left main coronary artery was involved in 33 of these patients, including 24 patients with no electrocardiographic evidence of anterior myocardial infarction. Exercise-induced U-wave inversion was observed in the absence of an abnormal resting 12-lead ECG. Only one of the 82 patients (1.2%) without significant coronary artery disease demonstrated exercise-induced U-wave inversion, and this patient had a primary cardiomyopathy. We conclude that exercise-induced inversion of the U-wave is highly predictiveof significant coronary artery disease and, more specifically, of disease of the proximal left anterior descending coronary artery.     

Progression of left main coronary artery stenosis following left anterior descending coronary artery angioplasty

Although recent clinical experience indicates a high success rate, percutaneous transluminal coronary angioplasty (PTCA) is still associated with serious complications which usually occur during or shortly after the procedure and are principally related to the lesion or segment of vessel being dilated. We report 2 cases of subacute progression within months of left main stenosis following successful, uncomplicated left anterior descending (LAD) coronary PTCA. Identification of left main trunk involvement may mandate earlier follow-up or intervention.     

Early recognition of critical stenosis high in the left anterior descending coronary artery

We describe an electrocardiographic finding indicative of critical stenosis high in the left anterior descending coronary artery. Patients at risk have prior angina and normal or minimally elevated cardiac enzyme levels. Their electrocardiogram exhibits no precordial Q waves and little or no ST elevation but, rather, deep and symmetric T waves. The presence of these findings indicates that the patient has had subendocardial ischemia or infarct, which, if not treated, may evolve to encompass the entire thickness of the myocardium. The need for prompt recognition of these critical warning signs is obvious. Critical care nurses must be prepared to recognize and act on these findings in a rapid, efficient manner.     

Giant left anterior descending coronary artery aneurysm

Small atherosclerotic coronary artery aneurysms are a relatively frequent incidental finding at angiography. We report an unusual case in that the aneurysm found was extremely large and therefore potentially at risk of rupture.     

Interventricular coronary steal induced by stenosis of left anterior descending coronary artery in exercising pigs

BACKGROUND. In pigs and humans, the left anterior descending coronary artery (LAD) supplies the left ventricular anterior wall (LVAW), anterior septum, and paraseptal band of the right ventricular anterior wall (RVAW). The purposes of our study were 1) to study the LAD flow distribution in these walls during preexercise, exercise, and exercise with LAD stenosis and 2) to analyze regional wall motion under these conditions. METHODS AND RESULTS. Nine pigs were instrumented with sonomicrometers for measuring percent wall thickening (%WTh) in LVAW, RVAW, and lateral (control) walls of both ventricles, a hydraulic occluder at the LAD origin, an LV pressure transducer, and catheters for radioactive microsphere injection (left atrium) and blood withdrawal (aorta). One month later, regional %WTh and flows were measured during preexercise, exercise, and continuing exercise with LAD stenosis resulting in more than 50% reduction in systolic LVAW %WTh with regard to exercise. LAD stenosis caused a dramatic decrease in total mean +/- SD LVAW subendocardial flow with regard to exercise (28.7 +/- 8 to 9.1 +/- 3.2 ml.min-1, p less than 0.0001) but not significant changes in either LVAW subepicardial flow or RVAW flow. The transmural distribution of flows within the LAD bed (as percentages of the total LAD flow in each experimental condition) showed that LAD stenosis redistributed flows with regard to exercise such that the LVAW subendocardial flow decreased from 26.4 +/- 4.2% of the total LAD flow to 11.8 +/- 4.3% (p less than 0.0001), whereas LVAW subepicardial flow increased from 32.9 +/- 2.3% of the total LAD flow to 45.5 +/- 7.9% (p less than 0.0001) and RVAW increased from 12 +/- 4.9% of the total LAD flow to 18.7 +/- 7.2% (p less than 0.0005). With exercise plus LAD stenosis, LVAW %WTh decreased from 43.2 +/- 8.4% to 17.2 +/- 9.7% (p less than 0.0001), but RVAW %WTh did not change. CONCLUSIONS. In the LAD bed of exercising pigs, LAD stenosis induces, in addition to transmural steal, an interventricular steal favoring the RVAW at the expense of the LVAW subendocardium. This steal results in preserved RVAW thickening despite severe LVAW hypokinesia.     

Long-term clinical outcome following coronary artery bypass grafting for isolated stenosis of the left anterior descending coronary artery

Aims To detail the clinical and angiographic profile, and long-termoutcome in consecutive patients with isolated stenosis of theleft anterior descending coronary artery undergoing bypass surgery. Methods A retrospective study of all patients (n=301) (January 1984–December1990) and undergoing coronary artery bypass grafting for isolatedleft anterior descending disease, in the Irish Republic, wasperformed. Survival was compared with that of an exact age-and gender-matched cohort. Results Mean age was 53 (±9·3) years. There were 238 (79%)males. In 241 (80%) patients an internal thoracic arterial bypassgraft was used. Operative mortality was 1·3%. Of the280 (93%) patients alive (16 cardiac deaths) at 7·1 (±1·9)years, 105 (35%) had angina, 26 (9%) suffered an interval myocardialinfarction, and repeat revascularization was required on 29(10%). Female gender (P=0·002), pre-operative myocardialinfarction (P=0·02), significant diagonal disease (P=0·04)and postoperative myocardial infarction (P=0·0001) wereindependently associated with survival. Females were more likelyto develop congestive cardiac failure (P=0·01) or postoperativeangina (P=0·03) than their male counterparts. Conclusions Survivorship (97%) and event-free survival (96%) at 5 yearsfollowing coronary artery bypass grafting for isolated leftanterior descending coronary artery disease is excellent andequivalent to an age-matched and gender-matched cohort.     

Mammary artery patch reconstruction of left anterior descending coronary artery

Most patients with diffuse coronary disease require endarterectomy for revascularization. In view of the high morbidity and mortality associated with coronary endarterectomy, patch angioplasty and reconstruction of the coronary artery was developed. We retrospectively evaluated 104 patients who underwent mammary artery patch angioplasty of the left anterior descending coronary artery. The procedure consisted of laying open the entire diseased segment of the coronary artery and patching it with an in-situ left internal mammary artery onlay patch, without endarterectomy, in an off-pump procedure. One (0.9%) patient died, 2 (1.8%) suffered perioperative myocardial infarction, and an intraaortic balloon pump was used in 2. The mean blood loss was 224 mL. Intensive care unit stay was 2.5 days, and hospital stay was 7.8 days. At 1-year follow-up, most patients were in New York Heart Association functional class I. Follow-up angiography was carried out in 16 patients and showed good patency of all anastomoses. Arterial patch reconstruction of the left anterior descending coronary artery can be performed safely and effectively in an off-pump procedure, with excellent early and intermediate results.     

Mid left anterior descending coronary artery originating from the right coronary artery

Dual connection of the left anterior descending coronary artery to the left and right coronary arteries is a very rare congenital anomaly. In this report we describe two cases in which the mid-position of the left anterior descending coronary artery is connected to the right coronary artery, one directly and the second by way of the infundibular artery. To the best of our knowledge, connection of the mid-position of the left anterior descending to the infundibular artery has not been previously described.     

Isolated anomaly of the left anterior descending coronary artery

An isolated anomaly of the left anterior descending coronary artery arising from the right sinus of Valsalva is described. A review of the literature shows that isolated anomalies of this vessel are very rare. However, the inability to visualize this vessel from the left sinus of Valsalva warrants careful search of the right sinus.     

Rotational atherectomy for left anterior descending artery septal perforator stenosis

Stenosis in large septal perforators can result in significant clinical ischemia. The distribution of the septal arteries is as large as many more commonly treated branch vessels. The interventricular septal blood supply has been ignored as a target for revascularization due to its inaccessibility for surgical revascularization, and the elastic recoil associated with balloon angioplasty in this location. Rotational atherectomy is a new therapeutic option for revascularization in this previously difficult location. The septal perforator ostium is the most common site of lesions and is functionally a branch ostial stenosis. We describe four cases in which rotational atherectomy was performed in patients with reversible ischemia due to septal artery stenosis. The acute angiographic results were stable, without evidence for immediate recoil. By debulking, facilitated angioplasty can yield stable acute results in this location. The small size of most septal branches and their angulated origin make rotational atherectomy challenging, and cases must be selected carefully. This previously ignored lesion location can be considered for revascularization in patients with suitable lesion and vessel morphology. Cathet. Cardiovasc. Intervent. 46:79–82, 1999. © 1999 Wiley-Liss, Inc.     

Myocardial bridging of the left anterior descending coronary artery and right coronary artery in a patient with mitral valve stenosis

Myocardial bridging is defined as the intramural course of a major epicardial coronary artery, and is mostly confined to the left ventricle and the left anterior descending coronary artery (LAD). Although it is considered to be a benign anomaly, it can lead to such complications as acute myocardial infarction, ventricular tachycardia, syncope, atrioventricular block and sudden cardiac death. Isolated myocardial bridging of the right coronary artery (RCA) and left circumflex artery have been reported in the literature In our case, myocardial bridging was observed in both the LAD and the RCA in a patient with mitral valve stenosis.     

Echocardiographic diagnosis of left anterior descending coronary artery disease

To determine the usefulness of the standard echocardiogram in the diagnosis of left anterior descending coronary artery disease proximal or distal to the first septal branch, coronary arteriograms and echocardiograms were performed in 77 patients with a chest pain syndrome. Seventy-nine percent of patients with proximal disease (15 of 19) had an abnormal septal motion measured as a posterior wall/interventricular septal (PW/IVS) excursion ratio greater than or equal to 2.5 compared with 10 percent of patients with distal disease (2 of 20) who had abnormal septal motion. Only 5 percent of patients without obstructive disease of the left anterior descending coronary artery (2 of 38) had abnormal septal motion. Proximal disease was found in 79 percent with abnormal septal motion in the echocardiogram (15 of 19) but in only 7 percent of patients with normal septal motion (4 of 58). Therefore, abnormal septal motion as measured by the PW/IVS excursion ratio in the echocardiogram is a useful index for the diagnosis of disease of the left anterior descending coronary artery when that disease is proximal to the first septal branch.     

Ten-year follow-up of percutaneous transluminal coronary angioplasty for proximal left anterior descending coronary artery stenosis in 351 patients

Objectives. We sought to evaluate the short- and long-term results of balloon angioplasty for stenoses in the proximal left anterior descending coronary artery.Background. Both the supposedly high rate of acute complications and relatively poor long-term results of balloon angioplasty for stenoses in the proximal left anterior descending coronary artery have led to a search for alternative interventional techniques.Methods. We analyzed the success rates and long-term follow-up results in 351 consecutive patients who underwent balloon angioplasty for stenosis of the left anterior descending coronary artery proximal to its first side branch. The power of the study was >80% in detecting a difference of 9% in the proportion of patients who survived at 10 years, assuming an 80% survival rate in the control group.Results. There were 60 ostial and 291 nonostial stenoses. Follow-up lasted a median of 85 months (range 0 to 137) and was 100% complete. The angiographic success rate was 90.9%. The clinical success rate was 86.3%. Nine patients (2.6%) died, 17 (4.8%) needed emergency coronary artery bypass graft surgery, and 10 (2.8%) developed a myocardial infarction. Several patients had subsequent complications. The success and complication rates were not significantly different for patients with ostial and nonostial stenoses. Ten years after balloon angioplasty, freedom from mortality was 80%, freedom from cardiac death was 87%, freedom from myocardial infarction was 84%, freedom from vessel-related reinterventions was 66%, and freedom from angina pectoris was 33%. There were more reinterventions for ostial stenoses, with a 1-year relative risk of ostial versus nonostial stenoses for related reinterventions of 1.7 (95% confidence interval 1 to 2.8, p = 0.049).Conclusions. More than 10 years ago, balloon angioplasty for stenoses in the proximal left anterior descending coronary artery, either ostial or nonostial, had a high success rate. Although the long-term results are satisfactory, ostial stenoses are associated with a higher early clinical restenosis rate requiring more reinterventions.     

Directional coronary atherectomy plus stent implantation vs. left internal mammary artery bypass grafting for isolated proximal stenosis of the left anterior descending coronary artery.

The aim of this study was to compare the short- (< 30 days) and long-term (> or = 30 days) clinical outcomes of left internal mammary artery bypass grafting (LIMA-LAD) and directional coronary atherectomy plus stent implantation (DCA + stent) in the treatment of isolated proximal left anterior descending coronary (LAD) lesions. One hundred and twenty-six patients underwent LIMA-LAD and 132 consecutive patients underwent DCA + stenting. The primary endpoint was the incidence of short- and long-term major adverse cardiac events (MACE); the secondary endpoints included any periprocedural events and long-term target vessel revascularization (TVR). We found no significant between-treatment difference in the occurrence of short-term MACE, and the long-term MACE rate per 100 person-years was 3.0 in the LIMA-LAD group and 4.6 in the DCA + stent group. After 5-year follow-up, 79% of the patients in the DCA + stent group and 89% of those in the LIMA-LAD group were still MACE-free. The risk of any periprocedural events was six times lower in the DCA + stent group, and the risk of TVR was six times higher. We conclude that both procedures lead to good short- and long-term follow-up results in isolated proximal LAD disease. As fewer periprocedural events and more TVRs occur after DCA + stenting than after LIMA-LAD, they can be considered valuable alternatives to each other.     

Usefulness of transthoracic color Doppler echocardiography for the identification of left anterior descending coronary artery stenosis.

We briefly describe our experience with transthoracic Doppler echocardiography for the direct evaluation of mid-distal left anterior descending coronary artery (LAD) stenosis. Three patients with previous myocardial infarction, scheduled for coronary flow reserve evaluation, underwent Doppler analysis of the mid-distal LAD. In all 3 cases, the mid-distal LAD stenosis was accurately quantified by the Doppler spectrum as confirmed by quantitative coronary angiography. Our study demonstrated the feasibility of transthoracic Doppler echocardiography in the discrimination of significant and non-significant mid-distal LAD stenosis. Limitations of such a technique could be related to the variable coronary anatomy and to the severity of the atherosclerotic process.