Exercise tests,atrial pacing,and myocardial lactate extraction in relation to coronary arteriography in young patients with angina pectoris

An exercise ECG and atrial pacing with a simultaneous study of myocardial lactate metabolism were used in conjunction with coronary arteriographies for the examination of 33 women and 22 men aged 40 or below whose working capacity was impaired by angina pectoris. Most of the patients fell into the age group 36 to 40. The men with coronary changes had come for examination in a shorter time than other patients. Coronary artery narrowings were found in five women and six men. The findings in other tests were pathological with greater frequency in patients with coronary stenosis. When evaluated on the basis of coronary arteriograms, the exercise and lactate tests proved to be reasonably sensitive (66.6 per cent) and specific (56.3 per cent and 68.8 per cent) in men. In women the sensitivity was high (80 per cent), but the specifivicity low (exercise 35 per cent, pacing 14.3 per cent, and lactates 38.5 per cent, respectively). The pacing ECG was also highly unspecific in men (37.5 per cent). Seven patients gave totally normal findings. The examination did not identify any specific group of patients with changes as indicatives of a constitutional disease of the myocardium. The coronary changes indicated that even in this age it is proper to obtain arteriograms in patients with low working capacity even in the absence of any other changes that angina pectoris itself. There are more false-positive findings in women than in men in exercise tests, and in many situations arteriography assures the best basis for further measures.     

The anginal syndrome associated with normal coronary arteriograms. Report of a six year experience

Although the occurrence of normal coronary arteriograms in patients with anginal pain is now recognized as a clinical entity, a large-scale study of such patients has not been reported. Accordingly, the historic aspects, laboratory findings and subsequent clinical course of 200 subjects (101 men and 99 women) with this syndrome were analyzed. Their average age was 47 years. No specific feature in the history could be discerned which separated these patients from those with angina due to coronary heart disease. The frequency of noncardiac sources of chest pain was similar in all patients. The electrocardiogram demonstrated abnormalities in the ST-T waves in slightly over 50 per cent of the patients, and the postexercise electrocardiogram was abnormal in another 20 per cent. Objective evidence for myocardial ischemia (myocardial lactate production) was three times more frequent in women than in men. The frequency of carbohydrate and/or lipid abnormalities was approximately half that in patients with coronary heart disease and did not correlate with the presence of myocardial ischemia. Long-term follow-up of these patients indicated that over half showed gradual improvement without specific therapy, whereas only 8 per cent had an increase in chest pain. Six patients died (four of unknown cause) in an average follow-up period of three years. Mortality, however, as determined by the life table method, was no greater than in a sex-age matched cohort derived from actuarial data. Although the etiology of this syndrome has not yet been demonstrated, its prognosis both in terms of persistence of pain and mortality appears to be benign.     

Coronary arteriographic findings in patients with axis shifts or S-T-segment elevations on exercise-stress testing

The exercise ECG's and coronary arteriograms of 158 patients were examined to evaluate the relationship of exercise-induced axis shifts and S-T-segment elevations to coronary artery disease. Eighteen of the 158 patients had exercise-induced S-T-segment elevations. Seventeen of these 18 patients had severe obstruction of the major coronary artery most compatible with the zone of ischemic localization. This obstruction was greater than 85 per cent in 16 patients and greater than 50 per cent in a seventeenth patient. The remaining patient had a normal coronary arteriogram and the most minimal exercise-induced S-T-segment elevations. Nine of the 158 patients had exercise-induced right axis shifts. Only 4 of these 9 patients had greater than 50 per cent obstruction of a major coronary artery, as compared to 103 of 154 patients in the total group studied. Also, there was no trend toward predominant involvement of any particular coronary artery in these 4 patients. Hence, it appears that this finding is not predictably associated with severe localized coronary artery disease. Only 4 of the 158 patients had exercise-induced left axis shifts. Three of these four patients had complete obstruction of the left anterior descending artery. But the group size was small, and the fourth patient had a normal coronary arteriogram. Hence, it is only possible to suggest that this finding may be associated with severe disease of the left anterior descending artery. The results of coronary artery surgery are discussed in a patient who had both a left axis shift and precordial S-T-segment elevations on his preoperative exercise ECG.     

Variations in right and left coronary blood flow in man with and without occlusive coronary disease.

The relation of angiographically recognized coronary occlusion to regional myocardial blood flow has not been studied adequately in spite of its clinical significance. This is particularly important, as revascularization procedures, based on angiographic studies, are being performed with increasing frequency. To compare the severity of reduction in flow to the severity of coronary occlusion, regional myocardial blood flow (85-Kr washout) was measured in 34 patients. Selective coronary anteriograms were obtained using the Sones technique, and occlusions were graded as a percentage of luminal diameter. Of 26 right coronary arteries for which satisfactory arteriograms and coronary blood flow measurements were obtained, 16 were normal and 10 had significant stenosis (greater than 50%). Dominant right coronary arteries appeared to have high flows (67 plus or minus 6 ml min-minus1 per 100 g muscle) and a greater incidence of occlusion (10 of 20) than nondominant arteries, which had less flow (41 plus or minus 2 ml min-minus1 per 100 g muscle) and a lower incidence of occlusion (1 of 8). Coronary blood flow in 16 normal left coronary arteries was 84 plus or minus 5 ml min-minus1 per 100 g muscle and in 15 with 50 per cent or greater occlusion, 68 plus or minus 3 ml min-minus1 per 100 g muscle. Though coronary blood flow appeared reduced when lesions of both the right and left coronary arteries were present, a critical reduction was seen only when occlusion was greater than 90 per cent.     

Variations in right and left coronary blood flow in man with and without occlusive coronary disease.

The relation of angiographically recognized coronary occlusion to regional myocardial blood flow has not been studied adequately in spite of its clinical significance. This is particularly important, as revascularization procedures, based on angiographic studies, are being performed with increasing frequency. To compare the severity of reduction in flow to the severity of coronary occlusion, regional myocardial blood flow (85-Kr washout) was measured in 34 patients. Selective coronary anteriograms were obtained using the Sones technique, and occlusions were graded as a percentage of luminal diameter. Of 26 right coronary arteries for which satisfactory arteriograms and coronary blood flow measurements were obtained, 16 were normal and 10 had significant stenosis (greater than 50%). Dominant right coronary arteries appeared to have high flows (67 plus or minus 6 ml min-minus1 per 100 g muscle) and a greater incidence of occlusion (10 of 20) than nondominant arteries, which had less flow (41 plus or minus 2 ml min-minus1 per 100 g muscle) and a lower incidence of occlusion (1 of 8). Coronary blood flow in 16 normal left coronary arteries was 84 plus or minus 5 ml min-minus1 per 100 g muscle and in 15 with 50 per cent or greater occlusion, 68 plus or minus 3 ml min-minus1 per 100 g muscle. Though coronary blood flow appeared reduced when lesions of both the right and left coronary arteries were present, a critical reduction was seen only when occlusion was greater than 90 per cent.     

Prognosis in patients rejected for coronary revascularization surgery

The clinical course, catheterization data, and coronary and left ventricular angiograms of 231 patients rejected for coronary revascularization surgery between 1971 and 1974 and treated conservatively were evaluated. Based upon analysis of available data, patients were classified into one of eight groups as follows: 66 patients with poor left ventricular function, 43 with atherosclerotic distal coronary vessels, one with advanced age, 13 with isolated stenosis of the left circumflex coronary artery, 14 with nonjeopardized collaterals to myocardium beyond the critical coronary stenosis, 25 with akinetic or dyskinetic myocardium beyond the critical coronary stenosis, and 19 with coronary lesions of 50 to 74 per cent of the luminal diameter were rejected; 50 patients were considered acceptable surgical candidates at the time of this review. At three years the actuarial survival rate for all patients was 77.6 per cent. However, those considered operable had a 36 month survival rate of 97.9 per cent. Ejection fraction was the only hemodynamic or clinical feature which had significant prognostic value. The probability of survival for three years was 89.7 per cent for those with ejection fractions greater than 34 per cent, whereas in others the survival rate was only 59.0 per cent (p < 0.001). Patients with poor distal vessels but adequate left ventricular function and those in the other five patient groups had three year survival rates exceeding 82 per cent. Patients with one, two and three vessel disease had three year survival rates of 88.3, 74.7 and 61.3 per cent, respectively. However, when subdivided according to left ventricular function, there was little difference in survival rates for patients with ejection fractions in excess of 34 per cent and one, two or three vessel disease. In patients with poor ventricular function survival rates were similarly low irrespective of the extent of coronary obstructive disease. Fifty-six per cent of patients returned to work, and 42 per cent had no or minimal symptoms. Only nine patients were housebound.Thus, (1) ejection fraction is confirmed as an important prognostic tool, (2) the extent and severity of coronary artery disease, and the condition of the myocardium are important chiefly as they affect the ejection fraction, (3) distal vessel disease does not affect survival adversely, and (4) extensive vascular and myocardial damage can be compatible with a long survival and productive life.     

The clinical course, early prognosis and coronary anatomy of subendocardial infarction.

The following prospective study was undertaken to observe the clinical course, early prognosis and coronary anatomy of patients with subendocardial infarction. Subendocardial infarction was defined as typical chest apin (greater than 15 minutes), serum enzyme elevation and persistent (greater than 48 hours) new T wave inversion and/or S-T segment depression in the absence of new pathologic Q waves. Fifty consecutive patients were defined, followed in a prospective manner and subjected to early coronary arteriography. A prior history of unstable angina was found in 33 patients (66 per cent); 22 patients (44 per cent) had significant dysrhythmias during the acute hospital phase, and seven patients (14 per cent) had evidence of mild left ventricular failure. Coronary arteriography demonstrated significant lesions (greater than 75 per cent narrowing in at least one vessel) in all 50 patients, with 30 patients (60 per cent) having either double- or triple-vessel disease. Follow-up (mean 10.6 months) revealed that 15 patients (30 per cent) had stable angina, 23 patients (46 per cent) unstable angina and only 12 patients (24 per cent) remained free of angina. Of 28 patients in a medically treated group, acute transmural infarctions developed in six (21 per cent) and one died (3 per cent). We conclude that subendocardial infarction is symptomatically an unstable entity, is associated with severe coronary artery disease and, in a medically treated group, is followed by a significant incidence of early transmural myocardial infarction (21 per cent). Therefore, these patients require in-hospital monitoring, careful follow-up and consideration for early coronary arteriography.     

Quantification of coronary arterial narrowing and of left ventricular myocardial scarring in healed myocardial infarction with chronic,eventually fatal,congestive cardiac failure

A qualitative and quantitative analysis is described of the amount of ventricular wall myocardial scarring and the degree and extent of coronary arterial narrowing by atherosclerotic plaques in the entire lengths of each of the four major epicardial coronary arteries in 18 necropsy patients with healed transmural myocardial infarcts, and chronic, eventually fatal, congestive heart failure. In all 18 patients, the healed infarcts involved greater than 40 per cent of the left ventricular wall, all had very dilated right and left ventricular cavities, all had hearts weighing more than 450 g (average = 587 g), all had intractable congestive heart failure for longer than three months (average = 2.3 years), and half had intraventricular mural thrombi. Of 1,012 five millimeter segments of the four major epicardial coronary arteries examined in the 18 patients (average 54 segments per patient), 298 segments (29 per cent) were 76 to 100 per cent narrowed in cross-sectional area by atherosclerotic plaques (in 16 control subjects = 6 per cent), 370 (37 per cent) were 51 to 75 per cent narrowed (controls = 35 per cent), 227 (23 per cent) were 26 to 50 per cent narrowed (controls = 43 per cent), and 117 (11 per cent) were 0 to 25 per cent narrowed (controls = 16 per cent). The amount of severe (>75 per cent) narrowing of the right, left anterior descending and left circumflex coronary arteries was similar in the 18 study patients. The left main coronary artery was not severely narrowed in any patient. The amount of severe narrowing in the distal one half of the right, left anterior descending and left circumflex coronary arteries was similar to that in the proximal halves of these three arteries. The per cent of 5 mm segments of coronary artery narrowed 76 to 100 per cent in cross-sectional area in the nine patients was similar to that in the nine patients without left ventricular aneurysm.     

Chest pain with angiographically insignificant coronary arterial obstruction: Clinical presentation and long-term follow-up

Among 3,242 coronary angiograms performed from November 1972 through October 1975 at the Massachusetts General Hospital, 175 patients had normal coronary arteries or luminal narrowings of less than 30 per cent. All patients were studied for chest pain, and none had experienced prior myocardial infarction. Subsequent information was available in 159 patients over a mean follow-up period of 42.7 months. There were no deaths, and only one myocardial infarction occurred during this period. However, among the patients followed, continued chest pain with episodes occurring at least once monthly was present in 54 per cent. In addition, 17 per cent of all patients required subsequent hospitalization and 44 per cent continued to receive antianginal medication. Nearly half of the group (46 per cent) suffered some limitation of activity, and 22 per cent stated that they had either changed jobs or stopped work because of chest pain. Continuing chest pain was significantly more common in women and in patients who had experienced chest pain for more than one year before angiography. However, typicality of chest pain for angina or the occurrence of electrocardiographic changes of ischemia prior to angiography did not predict continued chest pain during the follow-up period. Thus, although mortality and morbidity are low in this group of patients, the syndrome of chest pain with angiographically insignificant coronary artery obstruction has an important impact on the lives of a majority of those affected.     

Management of intractable ventricular tachyarrhythmias after myocardial infarction.

Twenty-five patients with recent or old myocardial infarction were studied because they had life-threatening ventricular arrhythmias that required repeated cardioversions and were intractable to medical management. All patients had had a large anterior infarction a mean of 4.6 weeks before the emergence of the arrhythmias and all had severe left ventricular dysfunction. Cardiac catheterization or autopsy revealed a left ventricular aneurysm in 18 of 18 patients and obstruction of the left anterior descending coronary artery in 20 of 20 patients. Of 16 patients treated surgically with aneurysm resection or coronary bypass grafting, or both, 10 (62 percent) were alive after 3 to 39 (mean 26) months of follow-up. The perioperative mortality rate was 31 percent and only one patient died during the postoperative follow-up period 4 months after discharge from the hospital. By contrast, all nine medically treated patients died either in the hospital (four patients) or suddenly within 2 months of discharge (five patients). Ventricular fibrillation was documented as the cause of death in five of these patients. Surgical intervention was found to improve significantly the survival of these patients (P less than 0.02). The perioperative mortality rate was lower when at least 4 weeks had elapsed from acute infarction to surgery (10 versus 67 percent) and when the procedure included coronary bypass grafting (13 versus 50 percent), although these differences were not statistically significant (P greater than 0.05).     

The heart in systemic lupus erythematosus and the changes induced in it by corticosteroid therapy: A study of 36 necropsy patients

The natural history of the cardiovascular manifestations of systemic lupus erythematosus (SLE) have been altered by corticosteroids which exert their own cardiovascular effects. This study describes clinical and necropsy observations in 36 corticosteroid-treated patients with SLE and compares them to necropsy observations in patients with SLE reported before the use of corticosteroid therapy. The 36 patients averaged 32 years of age, and 33 were women. Systemic hypertension was present in 25 (69 per cent) and left ventricular hypertrophy in 23 (64 per cent) patients. Hypertension was twice as common in the 19 patients who received this drug for more than 12 months (average 38 months) than in the 17 patients who received this drug for less than 12 months (average 6 months), and was almost five times more common among our patients than in patients with SLE in the presteroid era. Congestive cardiac failure occurred in 15 patients (43 per cent), eight times more frequent than that reported in noncorticosteroid-treated patients with SLE. Subepicardial and myocardial fat was increased in all 36 patients.Lupus carditis was similar in frequency but differed morphologically in our patients compared to those not treated with corticosteroids. Libman-Sacks-type endocardial lesions, present in 18 (50 per cent) of our patients, were smaller, fewer in number, univalvular rather than multivalvular, and mainly left-sided. Most verrucae were either partly or completely healed, and some were calcified. Pericarditis, present in 19 (53 per cent) patients, was predominantly of the fibrous type. Myocarditis was present in three patients, each of whom also had endocarditis and pericarditis. The lumen of at least one of the three major coronary arteries was narrowed more than 50 per cent by atherosclerotic plaques in 42 per cent of the 18 patients who received corticosteroids for more than 1 year, but in none of the 17 patients who received corticosteroids for less than 1 year. Four of the eight patients with narrowed coronary arteries had myocardial infarcts.Although vital to the management of SLE, corticosteroids have an over-all deleterious effect on the heart. Systemic hypertension and left ventricular hypertrophy appear or, when present, worsen; congestive cardiac failure increases; epicardial and myocardial fat increases, and coronary atherosclerosis appears to be accelerated.     

Correlation of abnormal Q waves, coronary pathology, and ventricular contractility.

Four hundred and ninety-two patients with coronary artery disease underwent analysis of their electrocardiograms, coronary arteriograms, and ventriculograms. Significant Q-waves were correlated with critical coronary occlusions (greater than or equal 75 per cent obstruction) and ventricular contractility. It was found that Q-waves correlate equally well with ventriculographic abnormalities and critical coronary occlusions. The Q-wave correlation varied from 77 to 87 per cent, depending on the area of myocardium under consideration, except for true posterior myocardial infarction, which correlated 55 per cent with ventriculographic abnormalities and 55 per cent with critical coronary occlusions. Significant Q-waves in Leads II, III, and aVF are better indicators of ventriculographic abnormality than in Leads III and aVF alone, whereas Q-waves in the latter two leads are more definitive than in Lead III alone. Patients who have critical coronary occlusions and normal electrocardiograms have normal ventriculograms in 71 to 78 per cent of the cases, again depending on the area of the myocardium under consideration. Thus, the normal electrocardiogram correlates better with the ventriculogram than with coronary pathology. The abnormal electrocardiogram correlates equally well with both.     

Coronary anatomy and arteriography in patients with unstable angina pectoris.

A prospective series of 188 patients with the syndrome of unstable angina pectoris undergoing coronary arteriography was reviewed to determine the spectrum of anatomic coronary artery disease, suitability for coronary revascularization and in-hospital morbidity and mortality. Thirty-two patients demonstrated normal to moderately diseased coronary arteries. None of these patients sustained myocardial infarction or died. Twenty patients (10.6 percent) had normal coronary arteriograms. Of the 156 patients having severe coronary artery disease (greater than 70 percent stenosis), 20 patients (13 percent) had left main coronary artery disease. One hundred forty-two patients (91 percent) were potential candidates for coronary surgery; 14 were not candidates because of distal vessel disease or poor left ventricular function. During cardiac angiography or in the subsequent hospital period 12 patients sustained a myocardial infarction and 7 of these died. Of these seven, six had left main coronary artery disease and one had three vessel disease. In three patients who died (1.9 percent of those with severe coronary artery disease) the death may have been related to cardiac catheterization because evidence of myocardial necrosis began within 24 hours of study. Thus, patients with the syndrome of unstable angina pectoris usually presented with severe coronary artery disease and were candidates for coronary revascularization. The anatomic severity of coronary artery disease appeared to be the most important factor contributing to myocardlal infarction or death after cardiac catheterization. Mortality after catheterization was primarily associated with left main coronary artery disease.     

Surgical treatment of postinfarction left ventricular aneurysm in 32 patients.

Thirty-two patients with large postinfarction left ventricular aneurysms shown at operation to consist of fibrous tissue are reported. All had angina and/or breathlessness, and none had a history of embolism. Thirty were correctly diagnosed by left ventricular cineangiography. Two of the 3 patients with inferior and 1 with an anterior aneurysm had associated ventricular septal defects, and 3 patients with an anterior aneurysm had mitral regurgitation. All had major coronary arterial lesions and 68 per cent had double or triple vessel disease. The aneurysm was excised in all patients; in 15 this was combined with saphenous vein bypass grafting of coronary arteries supplying surviving myocardium, in 3 with closure of a ventricular septal defect, and in 3 with mitral annuloplasty or replacement. Operative mortality was 6-2 per cent, and 79 per cent of the survivors are asymptomatic with average follow-up period of 18 months after operation.     

Echocardiographic assessment of abnormal left ventricular relaxation in man.

In 64 patients requiring cardiac catheterization for chest pain, echocardiograms showing anterior mitral leaflet and left ventricular cavity simultaneously were recorded. These were digitized and their first derivatives computed in order to study time relations between mitral valve and left ventricular wall movement in early distole. In 10 patients with normal left ventricular angiograms and coronary arteriograms, mitral valve opening began 1-1 +/- 9-3 ms (mean +/- SD) before the onset of outward wall movement, and reached peak opening velocity 2-0 +/- 13 ms after maximum rate of change of dimension. Virtually identical time relations were seen in 15 patients with normal left ventricular angiograms but with obstructive coronary artery disease (3-6 +/- 9-3 ms and 0-7 +/- 7-3 ms, respectively). These close relations were lost in patients with segmental abnormalities of contraction on left ventricular angiogram. In 19 such patients with normal septal motion, outward wall movement began 53 +/- 31 ms before the onset of anterior movement of the mitral valve leaflet, and this isovolumic wall movement accounted for 31 per cent of the total diastolic excursion. In 9 patients with reversed septal movement, these abnormalities were greater, 92 +/- 39 ms and 33 per cent, respectively, while in 11 patients with diffuse left ventricular involvement they were small, 5-5 +/- 13 ms and 3 per cent. Frame-by-frame digitization of cineangiograms was used to confirm these findings which appear to reflect an abnormal change in left ventricular cavity shape during isovolumic relaxation.     

Surgical treatment of postinfarction left ventricular aneurysm in 32 patients.

Thirty-two patients with large postinfarction left ventricular aneurysms shown at operation to consist of fibrous tissue are reported. All had angina and/or breathlessness, and none had a history of embolism. Thirty were correctly diagnosed by left ventricular cineangiography. Two of the 3 patients with inferior and 1 with an anterior aneurysm had associated ventricular septal defects, and 3 patients with an anterior aneurysm had mitral regurgitation. All had major coronary arterial lesions and 68 per cent had double or triple vessel disease. The aneurysm was excised in all patients; in 15 this was combined with saphenous vein bypass grafting of coronary arteries supplying surviving myocardium, in 3 with closure of a ventricular septal defect, and in 3 with mitral annuloplasty or replacement. Operative mortality was 6-2 per cent, and 79 per cent of the survivors are asymptomatic with average follow-up period of 18 months after operation.     

Coronary artery disease in young patients: arteriographic and clinical review of 40 cases aged 35 and under

Coronary arteriography was performed in 60 patients aged 35 or less with suggested coronary artery disease (CAD). Twenty patients (Group 1) had normal coronary arteries and 40 patients (Group 2) had one or more obstructive lesions. The left anterior descending artery was commonly involved followed by the right coronary and left circumflex arteries. The right coronary artery was most commonly completely obstructed. Single-vessel disease (50 per cent or greater obstruction) was found in 60 per cent of the patients, an incidence that is considerably higher than in studies of older patients. A total of 1.6 diseased vessels per patient was present. A hyperlipoproteinemia (HLP) was found in 68 per cent of Group 2 patients. Patients in Group 2 with an HLP had significantly more CAD than Group 2 patients with normal lipoproteins. The incidence of the following clinical features were not significantly different in Groups 1 and 2: typical angina, atypical angina, positive family history, smoking, hypertension, obesity, abnormal electrocardiogram, positive treadmill test, HLP, and diabetes mellitus. A fourth heart sound and a history of a myocardial infarction were significantly common in Group 2. Since almost all of the previously reported cases of myocardial infarction with normal coronary arteries have occurred in young patients, history of a myocardial infarction does not assure the presence of obstructive coronary artery lesions. It is suggested that coronary arteriography is a justifiable procedure in a young patient who presents with a clinical picture that is either compatible with or cannot be clearly distinguished from CAD.     

Clinical and hemodynamic evaluation of coronary collateral vessels in coronary artery disease

To appraise the functional significance of coronary collateral vessels, 78 consecutive patients with angina pectoris and at least 75 per cent obstruction in a major coronary vessel were studied clinically, hemodynamically, and angiographically and by stress testing. Forty-eight of them (62 per cent) had coronary collateral vessels. When patients with collaterals were compared with those without, the severity of angina pectoris and the number of positive treadmill ECG's were not statistically different. The patients with collaterals had a greater incidence of past myocardial infarction, $\text{33}\text{48}$ (68 per cent) vs. $\text{8}\text{30}$ (27 per cent) (P = 0.001); more extensive obstructive disease angiographically, 8.0 ± 0.4 vs. 6.3 ± 0.5 (P = 0.05); more abnormal pacing ventricular function curves, $\text{22}\text{23}$ (96 per cent) vs. $\text{9}\text{15}$ (60 per cent) (P = 0.01); and a greater incidence of left ventricular contraction abnormalities, $\text{43}\text{48}$ (90 per cent) vs. $\text{16}\text{30}$ (53 per cent) (P = 0.025).Patients who have coronary artery disease and collateral vessels cannot be distinguished from their counterparts without collaterals on a clinical basis except for a greater incidence of myocardial infarction in the former. Present evidence implies that collateral vessels may protect the patient by delaying the onset of angina pectoris, but when angina occurs these patients have more extensive coronary artery disease and greater myocardial dysfunction. In addition, collaterals, although not preventing, may limit the extent of myocardial infarction and reduce immediate mortality. The prognosis from the onset of angina pectoris may be worse in those patients with collateral vessels, however, because of their more extensive disease.     

Global and regional left ventricular response to bicycle exercise in coronary artery disease. Assessment by quantitative radionuclide angiocardiography.

The left ventricular response to bicycle exercise was evaluated in 60 patients with coronary artery disease and in 13 normal control subjects. Left ventricular ejection fraction, mean normalized ejection rate and regional wall motion were determined using first-pass radionuclide angiocardiograms obtained at rest and again during peak graded bicycle exercise. All normal subjects demonstrated improved left ventricular function with exercise. Left ventricular ejection fraction increased significantly from 67 ± 3 per cent (mean ± SE) at rest to 82 ± 4 per cent with exercise (p < 0.001). Similarly, the left ventricular ejection rate increased significantly from 3.47 ± 0.31 sec^?1 to 6.53 ± 0.42 sec^?1(p < 0.001). In contrast, in 44 of 60 patients with coronary artery disease, the ejection fraction or ejection rate either decreased or remained the same with exercise. New or exaggerated regional wall motion abnormalities were detected in 28 of 60 patients with coronary artery disease. Over-all, global or regional evidence of compromised left ventricular reserve was found in 48 of 60 patients with coronary artery disease.The major determinant of an abnormal left ventricular response to exercise was the presence or absence of electrocardiographic evidence of myocardial ischemia. Left ventricular ejection fraction decreased or remained the same with exercise in all patients with coronary artery disease and electrocardiographic ischemia. New regional wall motion abnormalities were detected in 20 of these patients. In this group, the left ventricular ejection fraction decreased from 66 ± 2 per cent at rest to 58 ± 2 per cent with exercise (p < 0.001), whereas the ejection rate was unchanged by exercise (rest 3.33 ± 0.21 sec^?1; exercise 3.34 ± 0.22 sec^?1, p > 0.05). Of the 30 patients with coronary artery disease who exercised to symptom-limiting fatigue without electrocardiographic ischemia, 18 demonstrated compromised left ventricular reserve with exercise. Twelve of the remaining patients with coronary artery disease had normal left ventricular reserve, in eight of whom ventricular function was completely normal both at rest and during exercise. In this group exercised to fatigue, the left ventricular ejection fraction increased from 53 ± 4 per cent at rest to 58 ± 2 per cent with exercise (p < 0.001). The ejection rate also increased from 2.48 ± 0.24 sec^?1 to 3.67 ± 0.39 sec^?1 (p < 0.001). The direction and magnitude of the left ventricular responses to exercise were not affected by long-term oral propranolol administration in 22 patients. Based upon either abnormal exercise left ventricular reserve or abnormal global and regional left ventricular function at rest, the over-all sensitivity of this radionuclide technic for the detection of coronary artery disease was 87 per cent (52 of 60 patients). These data demonstrate that exercise ventricular performance studies provide important physiologic insights into left ventricular functional reserve as well as a sensitive noninvasive approach for the detection of coronary artery disease.     

Long-term results of coronary revascularization--clinical, angiographic and hemodynamic findings (author's transl)

Clinical angiographic, and hemodynamic examinations were performed in 37 patients (mean age 54 +/- 6.5 years) with coronary heart disease 5.4 +/- 5.3 months and 57.0 +/- 15.3 months after coronary revascularisation. The results were compared with those of a preoperatively performed examination (8.1 +/- 5.9 months). Early postoperatively 57 per cent of the patients were free of angina and 32 per cent had marked relief, whereas preoperatively 73 per cent had severe angina (class III and class IV). Late postoperatively 51 per cent had no angina and 49 per cent had only slight or moderate angina. The patency rate of the aorto-coronary bypass grafts was 90 percent early and 83 per cent late postoperatively. Occlusions of the native coronary arteries proximal to the anastomosis were found in 26 per cent preoperatively, in 55 per cent early and in 84 per cent late postoperatively. The parameters of left ventricular function showed no significant alterations early and late postoperatively. The results demonstrate that the relief of angina, the patency rate of the aorto-coronary bypass grafts and the resting function of the left ventricle are approximately unchanged five years after coronary revascularisation.