Anomalous right coronary artery: a multimodality hunt for the origin.

Anomalous origin of the right coronary artery from the pulmonary artery (ARCAPA) is a rare congenital anomaly. Although there have been several cases of ARCAPA reported in the literature, we present a case which highlights the challenges of diagnosing this rare condition and the incremental value of using multiple imaging modalities. A healthy 48 year old female presented with angina and exertional shortness of breath. She had a normal cardiovascular examination, negative cardiac enzymes and an unremarkable chest X-ray. She did, however, have T-wave inversions in leads V1-V3. Transthoracic echocardiography (TTE), as the first imaging investigation, led to an initial provisional diagnosis of a coronary-cameral fistula. It showed unusual colour Doppler signals in the right ventricle and a prominent pattern of diastolic flow within the right ventricular myocardium, especially along the interventricular septum. A subsequent multimodality approach, correlating images from angiography, CT and MRI was instrumental in confirming the diagnosis of ARCAPA and planning for surgical correction. Cardiac CT and MRI are non-invasive, three-dimensional imaging modalities with high diagnostic accuracy for coronary artery anatomic anomalies. If echocardiography and conventional angiography have been inconclusive, cardiac CT and MRI are especially important diagnostic tools.

Interventions for coronary stenosis--a Canadian experience of 30 revolutionary years.

OBJECTIVE: To report 2324 coronary stenosis interventions (Vineberg procedures [VbP], coronary artery bypass graft operations [CABG] and percutaneous transluminal coronary angioplasties [PTCA]), in 1711 patients of a Canadian military hospital between 1965 and 1995 and to report their evolution and interaction in a historical context. DESIGN: Retrospective examination of clinical and angiographic findings in hard records, collected from the beginning for long term follow-up and later embedded in a custom-designed computer database. PATIENTS: Most were male, mean ages 43.2 and 43.3 years for first and second VbPs; 48.9 and 58.2 years for first and repeat CABGs; and 53.4 and 59.9 years for first and repeat PTCAs, respectively; 12% of all patients were 39 years old or younger at the first intervention. INTERVENTIONS: There were 160 VbPs, 1637 CABGs and 527 PTCAs. Of 1711 subjects, 74% had only one procedure, 15% had more than one of the same kind, and 11% had more than one of different kinds. MAIN RESULTS: Perioperative mortality for VbPs was 4.4%; for 'isolated' first CABGs it was 1.4% and 6.6% for reoperations, when other concurrent major cardiac procedures, excepting ventricular aneurysm repair, were excluded. It was 0.4% for PTCAs. Perioperative mortality for all 1761 'isolated' coronary interventions necessitating thoracotomy, during 30 years, was 2.4%. Angiographic follow-up rates were high and some findings are reported, including early postoperative patency rates for 5065 coronary bypass grafts, and long term follow-up data on graft patency and disease. CONCLUSIONS: Each intervention was used to circumvent or relieve coronary stenosis, in the early years when it became available and, later, as was most appropriate for dealing with specific clinical problems. The impact of advances in the evolution of these interventions on therapeutic decision-making is discussed. Finally, tributes are paid to those responsible for making these procedures possible, including a Canadian surgeon whose role was pivotal.

Coronary bypass graft fate and patient outcome: angiographic follow-up of 5,065 grafts related to survival and reoperation in 1,388 patients during 25 years.

OBJECTIVES: We sought to examine, angiographically, the longterm fate of a large number of mainly venous coronary bypass grafts and to correlate graft patency and disease with patient survival and reoperation. BACKGROUND: Much is known about bypass graft patency and disease, but the precise relation between graft fate and patient outcome has not been substantiated and documented. METHODS: A total of 1,388 patients underwent a first coronary artery bypass graft procedure at a mean age of 48.9 years, 234 had a second bypass procedure at a mean age of 53.3 years, and 15 had a third bypass procedure at a mean age of 58.2 years during the 25-year period from 1969 to 1994. Most were male military personnel or veterans; 12% were < or = 39 years old. Of 5,284 grafts placed, 91% were venous and 9% arterial. Angiograms were performed on 5,065 (98% of surviving) grafts early, on 3,993 grafts at 1 year and on 1,978 grafts at 5 years after operation; other examinations were also performed up to 22.5 years after operation, and 353 grafts were examined after > or = 15 years. Grafts were graded for patency and disease. The status of all patients was known at the study's end. RESULTS: The perioperative mortality rate was 1.4% for an isolated first coronary bypass procedure, 6.6% for reoperation. Vein graft patency was 88% early, 81% at 1 year, 75% at 5 years and 50% at > or = 15 years; when suboptimal grafts, graded B, were excluded from calculation, the proportion of excellent grafts, graded A, decreased to 40% after > or = 12.5 years. After the early study, the vein graft occlusion rate was 2.1%/year. Internal mammary artery graft patency was significantly better but decreased with time. Vein graft disease appeared by 1 year and the rate accelerated by > or = 2.5 years, involving 48% of grafts at 5 years and 81% at > or = 15 years; 44% of the latter grafts were narrowed > 50%. Survival of all patients was 93.6% at 5 years. 81.1% at 10 years, 62.1% at 15 years, 46.7% (150 patients) at 20 years and 38.4% (25 patients) at 23 years after operation. Survival decreased as age increased, but curves approximated "normal" life expectancy for older patients. Survival curves at all ages showed a steeper decline after 7 years. The rate of reoperation increased between 5 years and 10 to 14 years, then decreased to stable levels. Coronary atheroembolism from vein grafts was the major cause of morbidity and mortality associated with reoperation. Vein graft patency and disease were temporally and closely related to reoperation and survival. CONCLUSIONS: Coronary bypass graft disease and occlusion are common after coronary artery bypass grafting and increase with time. They are major determinants of clinical prognosis, specifically measured by reoperation rate and survival. Intraoperative graft atheroembolism was a major reoperation hazard. Reoperation is definitely worthwhile but entails identifiable risks that must be dealt with.

Exercise echocardiography after coronary artery bypass surgery: correlation with coronary angiography.

OBJECTIVES: Our aim was to assess, in patients after coronary artery bypass surgery, how well exercise echocardiography predicts the presence of vascular compromise on angiography. BACKGROUND: Because late graft failure frequently occurs after bypass surgery, a reliable noninvasive technique is needed to identify those patients who would benefit from angiographic study. METHODS: In 182 patients, a total of 213 symptom-limited treadmill exercise electrocardiograms (ECGs) and exercise echocardiograms were performed in association with coronary and bypass angiography 2 weeks to 21 years after bypass surgery. RESULTS: There were more inconclusive exercise ECGs (28%) than exercise echocardiograms (9%). The positive predictive value was 85% for the exercise echocardiogram versus 62% for the exercise ECG; the corresponding negative predictive values were 81% versus 52%. The accuracy of the exercise echocardiogram was linked to the degree of underlying vascular compromise. After excluding cases with nondiagnostic results, due to either submaximal stress or poor image quality, the exercise echocardiogram detected 46 of the 60 cases with vascular compromise in one region (sensitivity 77%) and 47 of the 49 cases with compromise in two or three regions (sensitivity 96%). Similarly, an abnormal exercise echocardiogram had a positive predictive value of 71% for vascular compromise in one region and 98% for compromise in two or three regions. Most false negative exercise echocardiographic results were associated with posterolateral single-region vascular compromise on angiography. CONCLUSIONS: This study confirms a high positive and negative predictive value of exercise echocardiography in the detection of vascular compromise in patients after bypass surgery. It is clearly superior to exercise electrocardiography in predicting which patients will have angiographically significant graft or arterial lesions, and it can be used to obtain a better selection of patients for angiographic study.

Aortocoronary vein graft spasm during angiography.

OBJECTIVE: To determine the frequency and clinical significance of aorto-coronary vein graft spasm during angiography. DESIGN: Retrospective review of angiograms and subsequent correlation with clinical outcome. PATIENTS: A total of 1264 patients having bypass surgery between 1971 and 1986. MAIN RESULTS: Twenty-four men, aged 31 to 54 years, demonstrated spasm in 31 vein grafts at angiography. Vein graft spasm occurred in 13 anterior descending, 12 right coronary, four marginocircumflex and two diagonal grafts. Spasm occurred less than six months after surgery in six cases, six to 12 months after surgery in 18 cases and five or more years after surgery in two cases. There was technical difficulty associated with the intubation of 15 of the 31 grafts. In all but two of the cases, the graft spasm was proximal. There was ischemic discomfort and/or electrocardiographic changes in nine patients, with ventricular fibrillation in three cases. Three cases of very severe vein graft spasm could be reversed with vasodilators, but in three others it could not be relieved and the grafts occluded irreversibly, leading to myocardial infarction in two patients. CONCLUSION: Aortocoronary vein graft spasm may occur during angiography and may be associated with more technically difficult graft intubation. Severe vein graft spasm may respond to vasodilators but can progress to graft occlusion with myocardial infarction. Aortocoronary vein graft spasm during angiography is not related to any higher incidence of spontaneous graft closure or recurrent angina.

Repeated plaque rupture in the same bypass graft.

A 51-year-old man experienced a plaque rupture at the site of a shallow plaque in his anterior descending bypass graft and went on to suffer a myocardial infarct. Angiography, five months later, showed excellent recanalization; however, one month after that angiogram, the patient presented with unstable angina and evidence of plaque rupture at the same site. The presence of plaque in a graft indicates risk for future plaque rupture, but there appear to be no definite indicators to identify the specific plaque that is at highest likelihood of rupture.

Coronary bypass graft fate: long-term angiographic study.

In 222 patients, 741 venous coronary bypass grafts were studied angiographically early, at 1 year and at a late examination at greater than 6.5 years (mean 9.6) after operation; 565 of these grafts were also examined 5 years postoperatively. Grafts were graded for patency and disease considered to be atherosclerotic and for both extent and profile of lesions. Graft occlusion rates increased steadily from 8% early to 20% at 5, 41% at 10 and 45% at greater than 11.5 years after operation. All grafts were considered free of atherosclerosis early, but disease appeared in 8% at 1 year, increasing to 38% at 5 and 75% at 10 years postoperatively. Increasing involvement of vessel wall area was associated with greater protrusion of lesions into the graft lumen. Diseased grafts became more so at subsequent examinations, with occlusion occurring in many. However, absence of disease had little prognostic significance because diseased and abruptly occluded grafts were generated in those with healthy appearance at earlier examinations. For instance, 82% of very diseased grafts at the 5 year study originated from normal grafts at 1 year and 73% of occluded grafts at 1 year had appeared normal early postoperatively. Of 590 patent grafts free of disease at 1 year, 30% were occluded at the late examination, 76% of those patent were diseased, 55% of these were diffusely diseased and 35% were greater than 50% narrowed. Only 17% of the original 590 patent grafts were healthy at this time. Bypass graft atherosclerosis severely limits the long-term utility of these grafts. It is suggested that the solution may lie in some powerful drug regimen.

Coronary artery disease and coronary bypass grafting in young men: experience with 138 subjects 39 years of age and younger.

One hundred thirty-eight men aged less than or equal to 39 years had coronary bypass grafting during a 13 year period. Angina was the presenting symptom in 77% and of these patients, one-third had unstable angina. More than half of the patients had experienced at least one myocardial infarct. There was a high incidence of coronary risk factors, especially smoking. Nineteen patients (13.8%) had left main coronary artery stenosis (it was isolated in two); 13.8, 24.6 and 60.2% had single, double and triple vessel disease, respectively. Left ventriculograms showed serious functional impairment in 42%. A total of 461 coronary bypass grafts, 3.34 per patient, were placed; almost all were vein grafts. There were no operative deaths. Transmural myocardial infarction occurred in 4.3% of patients. All bypass grafts were opacified angiographically early after operation, 95% at 1 year, 56% at 5 years and 26% at 10 years after operation. Some patients also had coronary angiograms, dictated by clinical events, between 1 and 5 and between 5 and 10 years postoperatively. Patency rates for bypass grafts were comparable with those previously reported and were acceptable, although they decreased with time. However, increasing evidence of atherosclerosis of bypass grafts was seen beyond 1 year, particularly beyond 5 years. Of 23 subjects with a coronary bypass reoperation, 2 died and 44% had perioperative transmural myocardial infarction. During follow-up, 13.8% of the patients died, survival being 95, 84 and 76% at 5, 10 and 12 years, respectively. It is considered that the patients were advantageously treated with coronary bypass grafting especially in the short-term. However, bypass graft patency steadily decreased with the passage of time and graft atherosclerosis became an increasingly important problem.

Serum magnesium and potassium in acute myocardial infarction. Influence on ventricular arrhythmias.

Over a 13-month period, serum potassium and magnesium levels were measured in 590 patients admitted to a coronary care unit. Hypokalemia, often in the absence of diuretic use, occurred in 17% of the 211 patients with acute myocardial infarction. Patients with acute myocardial infarction and a potassium level of less than 4.0 mEq/L (4.0 mmol/L) had an increased risk of ventricular arrhythmias (59% vs 42%). Because hypokalemia is common in acute myocardial infarction and is associated with ventricular arrhythmias, routine measurement of serum potassium levels and prompt correction are recommended. Hypomagnesemia occurred in only 4% of the patients, but it was more common in the group with acute myocardial infarction than in the group without myocardial infarction (6% vs 3%). Ventricular arrhythmias occurred in ten of the 13 patients with both acute myocardial infarction and hypomagnesemia, but eight of these patients also had low serum potassium levels. This low incidence of hypomagnesemia does not justify routine measurement of serum magnesium levels. However, the mean level (2.5 +/- 0.4 mg/dL [1.03 +/- 0.16 mmol/L]) in a reference population of healthy volunteers was unexpectedly high and suggests that the low incidence of hypomagnesemia in our population may not be applicable to other centers and may reflect a higher magnesium content in our geographic area of southeastern Ontario.

Atherosclerosis of coronary artery bypass grafts and smoking.

Follow-up angiography was performed at selected intervals on 340 men who had undergone coronary artery bypass surgery. There were 1160 grafts, but 112 were excluded from study because they occluded shortly after the operation. After 5 years 115 patients were smokers and 225 were nonsmokers. The mean number of grafts per patient was similar in the two groups. We classified each graft according to irregularities in graft outlines and graft patency and found disease-free grafts in 39% of the smokers and 52% of the nonsmokers; the proportion of diseased or occluded grafts was greater in the smokers than in the nonsmokers. Our results do not identify the effect of smoking cessation after bypass surgery, but they do suggest that men who continue to smoke are at significantly greater risk of atherosclerosis and occlusion than nonsmoking men.

Coronary bypass graft fate. Angiographic study of 1,179 vein grafts early, one year, and five years after operation.

A total of 1,179 vein grafts were studied angiographically in 353 (45%) unselected survivors (male, mean age 45.5 years) of 786 coronary bypass operations. Studies were conducted early (0.96 months), 1 year (12.8 months), and 5 years (59.7 months) postoperatively. A previously described technique was used to grade the patency of the grafts, and a new technique was used to assess intimal irregularity, presumably caused by atherosclerosis; this new technique indicated both intimal surface distribution of disease and profile (relief or elevation). Ten percent, 17%, and 26% of grafts were occluded early, at 1 year, and at 5 years, respectively. Distal anastomotic defects were the commonest cause for low grades in the patency classification. Irregularities in patent grafts increased from 9% at 1 year to 42% at 5 years, with 11% of all the 1 year lesions and 20% of all the 5 year lesions having a high profile (more than 50% graft stenosis); of the lesions categorized as showing the widest surface spread, 17% were in high relief at 1 year and 34% at 5 years. Thus, the lesions we believed to be atherosclerotic proliferated in both surface spread and elevation. All severely diseased grafts at the 1 year study had been normal in outline early; 79% at the 5 year study had been disease free at 1 year. All newly occluded grafts at the 1 year study had been normal in outline and 82% had had good patency early; 78% of newly occluded grafts at the 5 year study had been disease free at 1 year and 77% had had good patency. Normal appearance of the intima in grafts studied at 1 year had no prognostic value for 5 year findings. However, 62% of all grafts with the appearance of intimal disease at 1 year showed deterioration by 5 years, and 28% were occluded. The differences between these outcomes are highly significant (p less than 0.0005). In conclusion, the appearance of intimal irregularity compatible with atherosclerosis in a coronary bypass graft 1 year after operation carried a poor prognosis for adverse angiographic change at 5 years. On the other hand, normally appearing intima at 1 year had no predictive valve for the 5 year study despite a generally better prognosis for nondiseased grafts.

A new surgical technique to correct double chambered right ventricle associated with anomalous left anterior descending coronary artery.

A 42 year old woman with symptomatic double chambered right ventricle had the additional features of an anomalous left anterior descending coronary artery and attachment of the tricuspid valve to the area of subinfundibular stenosis which precluded conventional repair. A non-valved Dacron conduit was used to bypass the obstruction. The patient is asymptomatic two years later.