"Silent" myocardial ischemia during and after exercise testing in patients with coronary artery disease

Although many patients with coronary artery disease (CAD) have a positive exercise test without pain, the frequency and significance of this "silent" ischemia is unclear. Therefore, we studied 122 consecutive clinically stable patients with angiographically defined CAD (greater than 75 per cent luminal stenosis) and a positive exercise test. Seventy-eight patients had pain or anginal equivalent during or after a positive exercise test; 44 did not, including 32 (26 per cent) with no symptoms at all. Patients were evaluated as to age, sex, prior myocardial infarction, congestive failure, hypertension, diabetes mellitus, and digoxin or propranolol therapy--in addition to anginal symptoms before, during, or after the exercise itself. Extent of CAD, presence of collaterals, and left ventricular ejection fraction were also determined. All exercise tests were evaluated for evidence of ST-T abnormalities or prior infarction on the control ECG as well as peak heart rate during exercise and post-exercise degree of ST segment depression. There were no significant differences between patients with and without exercise-induced pain in regard to any of the clinical and angiographic features noted above, demonstrating that "silent" myocardial ischemia during or after exercise testing is not uncommon and is not readily attributable to any obvious clinical or catheterization findings. Further studies are necessary to determine if patients with evidence of "silent" myocardial ischemia are especially prone to sudden death.     

Post-extrasystolic potentiation of ischemic myocardium by atrial stimulation

The response of acutely ischemic myocardium to post-extrasystolic potentiation (PESP) was evaluated in 11 mongrel dogs. Mercury-in-silastic length gauges were sutured to the epicardial surface of the left ventricle; left ventricular pressure was determined via an apical large-bore catheter-transducer system and controlled by volume manipulation. The anterior descending coronary artery was then ligated, and single premature atrial contractions were introduced via an external stimulator. Thirty minutes after occlusion, shortening during ejection had decreased an average of 81 +/- 8 per cent, from 1.30 +/- 0.29 to 0.32 +/- 0.05 mm. PESP initially induced a marked restoration toward normal segmental contraction as systolic shortening increased significantly to 1.14 +/- 0.23 mm. Additionally, paradoxic systolic expansion, when present, reverted to a normal pattern of contraction during PESP. Responsiveness to PESP deteriorated progressively with time over 3 hours following occlusion until the muscle became essentially totally unresponsive to this stimulus. It is concluded that a single premature atrial beat may be used to induce PESP and provides an effective stimulus for contractile reserve of acutely dysfunctional ischemic myocardium. Loss of responsiveness to PESP may represent the progression to nonviability following acute ischemia.     

Ischemic myocardial injury during cardiopulmonary bypass surgery

ECG's and serum levels of SGOT, LDH, and CPK were examined during the immediate postoperative period in 126 patients who had cardiac surgery during cardiopulmonary bypass. None had coronary disease and valve replacement was performed in 97 patients. Miscellaneous procedures not involving the coronary arteries were performed in 29. In surviving patients, ECG signs of acute myocardial infarction appeared in 8 (7 per cent) and changes compatible with acute ischemic injury were seen in 38 (30 per cent). Elevation of SGOT exceeding 90 units occurred in 32 per cent of patients and LDH levels over 900 units occurred in 37 per cent. In patients with ECG evidence of postoperative infarction or ischemia, 70 per cent had abnormal SGOT levels and 70 per cent had abnormal LDH levels. In 40 patients with SGOT levels exceeding 90 units, 80 per cent had ECG evidence of acute infarction or ischemia. In 80 patients without ECG changes, only 10 per cent had SGOT levels exceeding 90 units. CPK levels correlated poorly with ECG evidence of ischemia or infarction. Patients who demonstrated ECG and serum enzyme evidence of ischemic injury or myocardial infarction had longer total perfusion times during surgery (P < 0.001) but no relationship to aortic cross clamp time was observed. ECG evidence of acute myocardial ischemia with elevation of serum enzymes is frequently observed following cardiopulmonary bypass surgery. Serial ECG's and measurements of postoperative serum enzymes provide useful information regarding myocardial injury and the effectiveness of bypass perfusion in protecting the myocardium during cardiopulmonary bypass sugery.     

Vectorcardiographic, electrocardiographic, and angiographic correlations in apparently isolated inferior wall myocardial infarction.

Twenty-six patients with ECG evidence of localized inferior myocardial infarction and poor ejection fraction (less than 50 per cent) were compared with 26 patients with similar ECG's, but with normal ejection fraction (over 50 per cent). The poor ejection fraction group had significantly more frequent and more severe disease in left anterior descending artery and a higher incidence of triple coronary obstruction than the normal ejection fraction group. The poor ejection fraction group had a significantly greater incidence of ventricular asynergy in the anterior and apical segments of left ventricle. Vectorcardiography was available in 35 of the 52 patients studied and frequently supplied diagnostic information not available in the scalar ECG's. Of 18 patients with scalar ECG patterns of isols, vectorcardiography identified five cases with anterior infarction, three with left ventricular hypertrophy, and one with left anterior hemiblock. Vectorcardiography is a valuable supplementary tool in the clinical assessment of patients with apparently isolated inferior infarction. When extensive coronary and poor ventricular function exist, VCG clues may be expected in about half the patients.     

Diagnostic and prognostic significance of electrocardiographic and CPK isoenzyme changes following coronary bypass surgery: correlation with findings at one year.

The incidence of ECG (14 per cent) indication of acute myocardial infarction complicating coronary artery bypass surgery is documented, corroborating the findings of prior series. An additional 32 per cent of patients had appearance of myocardial specific CPK-MB in serum during the immediate postoperative period. All patients surviving to 1 year following surgery (93 of 103) were asked to return for repeat cardiac catheterization to determine the presence and extent of interim ventricular contraction abnormalities. Sixty-five (70 per cent) of the group returned for evaluation. Preoperative and 1 year postoperative left ventriculograms were compared to determine if new contraction abnormalities would confirm the specificity of perioperative QRS and isoenzyme changes, and if the absence of new abnormalities would confirm their sensitivity. The majority of patients (65 per cent) had new areas of asynergy. However, 73 per cent of these were confined to the apex and thus could have been produced by the vent employed during cardiopulmonary bypass. QRS changes were 100 per cent specific and CPK-MB appearance was 78 per cent specific but they were only 20 and 54 per cent sensitive, respectively. Indeed, 46 per cent of those with new asynergy which was non apical had neither QRS change nor CPK-MB appearance. Thus QRS changes were always--and CPK-MB appearance was usually--associated with new asynergy but, in addition, many patients with no perioperative indication of infarction developed new areas of left ventricular contraction abnormality within the first postoperative year.     

Usefulness of BMIPP SPECT to evaluate myocardial viability, contractile reserve and coronary stenotic progression after reperfusion in acute myocardial infarction.

Using combined 123I-BMIPP (BMIPP), 201Tl (Tl) and 99mTc-PYP (PYP) myocardial SPECT imaging, risk areas of acute myocardial infarction were documented in the acute stage, and then these images were evaluated for how well they reflected muscle viability, contractile reserve and coronary stenotic progression subsequent to reperfusion therapy. Patients who only experienced a first attack of myocardial infarction were enrolled. In total, 36 cases who had had the occluded artery successfully reperfused were examined during the past year. They had no significant vessel disease except for the culprit single artery. The patients were comprised of 32 men and 4 women. The mean age was 59.5 years. All patients underwent coronary angiography and left ventricular (LV) angiography in the emergency room. BMIPP/Tl and PYP myocardial SPECT were conducted in the acute stage and chronic stage. In the chronic stage LV angiography was repeated to assess the improvement of LV wall motion. The response to postextrasystolic potentiation (PESP) testing was performed to estimate myocardial contractile reserve. The risk area of acute myocardial infarction (AMI) was documented by reduced BMIPP accumulation. The size of reduced BMIPP accumulation was larger than that of PYP accumulation. A BMIPP/Tl discrepancy and PYP accumulation were documented to assess myocardial viability. Both improvement in LV wall motion and augmentation of PESP response were more closely related to a BMIPP/Tl discrepancy in the presence or absence of PYP accumulation. Therefore, it would be possible to evaluate myocardial viability and contractile reserve by the BMIPP/Tl discrepancy. In patients with good viability, it is important to predict whether there is coronary stenotic progression or not. In this study, we demonstrated that most patients with improved BMIPP images had no significant progression at the site of intervention. Serial observation of BMIPP images from the acute stage to the chronic stage might enable us to predict the progression of coronary stenosis.     

Hemorrhagic myocardial infarction associated with aortocoronary bypass revascularization.

Experimentally, hemorrhage and extension of myocardial infarction occur commonly when there is reperfusion after coronary artery occlusion. To investigate this hazard in a clinical setting, we compared the histopathologic picture of myocardial infarction in 44 patients who had undergone aortocoronary bypass: 14 (Group I) had myocardial infarction that predated aortocoronary bypass by 1 to 7 days; 13 (Group II) had infarction 1 to 14 days after the surgery; and 17 (Group III) had infarction 15 to 90 days postoperatively. All 44 patients had two or more coronary arteries with luminal narrowing of more than 75 per cent and patent vein grafts to arteries supplying areas of infarction. Hemorrhagic infarcts were present in 57 per cent of patients (eight of 14) in group I and 38 per cent of patients (five of 13) in Group II, contrasting with 6 per cent of patients (one of 17) in Group III (P < 0.005 and P < 0.05, respectively). In hemorrhagic infarcts, the extravasated blood formed irregular intramural dissecting tracts beyond the area of infarction, and foci of myocardial necrosis were present in the border zones. Infarcts affected more than 50 per cent of the left ventricular muscle in 64 per cent of cases of hemorrhagic infarction and in 13 per cent of cases of nonhemorrhagic infarction (P < 0.05). The prevalence of hemorrhagic infarction after revascularization may account for the high mortality of evolving and perioperative myocardial infarction associated with aortocoronary bypass, and this finding militates against wholesale immediate revascularization in patients who have uncomplicated myocardial infarction.     

Left anterior descending coronary artery obstruction. Clinical, electrocardiographic, and angiographic correlates.

Seventy-six patients with severe (greater than 80%) occlusive left anterior descending coronary artery disease by coronary angiography were examined for the electrocardiographic characteristics of this disease in the presence (group A 59 patients) or the absence (group B 17 patients) of anterior wall asynergy (akinesis or dyskinesis). The incidence of clinically documented anterior myocardial infarction in these two groups of patients was examined. The collateral circulation to the left anterior descending coronary artery was also examined in the groups of patients with and without anterior wall asynergy. Thirty-eight of 59 (64%) patients with anterior wall asynergy (group A) showed electrocardiographic signs of anterior myocardial infarction, 17 per cent showed probable electrocardiographic signs of anterior myocardial infarction and 19 per cent showed no electrocardiographic signs. None of the 17 patients without anterior wall asynergy (group B) showed electrocardiographic signs of anterior myocardial infarction. In group A 74.6 per cent had documented clinical evidence of previous anterior myocardial infarction. Collateral filling of the distal left anterior descending coronary artery was seen in 71 per cent of group A and 100 per cent of group B patients. There was a significantly higher incidence (P = 0.02) of collateral filling in the patients without electrocardiographic evidence of definite anterior myocardial infarction (93% of 28 patients), than in those who showed definite electrocardiographic evidence of anterior myocardial infarction (66% of 38 patients).it is concluded that severe occlusive left anterior descending coronary artery disease with anterior wall myocardial asynergy is usually associated with electrocardiographic signs of anterior myocardial infarction, whereas equally severe left anterior descending coronary artery disease without anterior wall asynergy is rarely associated with electrocardiographic abnormalities of anterior myocardial infarction. Severe left anterior descending coronary artery obstruction without electrocardiographic and angiographic evidence of anterior myocardial infarction is usually associated with collateral circulation to the left anterior descending coronary artery and collateral circulation to the left anterior descending coronary artery is present less frequently when obstruction is associated with anterior myocardial infarction.     

Left anterior descending coronary artery obstruction. Clinical, electrocardiographic, and angiographic correlates.

Seventy-six patients with severe (greater than 80%) occlusive left anterior descending coronary artery disease by coronary angiography were examined for the electrocardiographic characteristics of this disease in the presence (group A 59 patients) or the absence (group B 17 patients) of anterior wall asynergy (akinesis or dyskinesis). The incidence of clinically documented anterior myocardial infarction in these two groups of patients was examined. The collateral circulation to the left anterior descending coronary artery was also examined in the groups of patients with and without anterior wall asynergy. Thirty-eight of 59 (64%) patients with anterior wall asynergy (group A) showed electrocardiographic signs of anterior myocardial infarction, 17 per cent showed probable electrocardiographic signs of anterior myocardial infarction and 19 per cent showed no electrocardiographic signs. None of the 17 patients without anterior wall asynergy (group B) showed electrocardiographic signs of anterior myocardial infarction. In group A 74.6 per cent had documented clinical evidence of previous anterior myocardial infarction. Collateral filling of the distal left anterior descending coronary artery was seen in 71 per cent of group A and 100 per cent of group B patients. There was a significantly higher incidence (P = 0.02) of collateral filling in the patients without electrocardiographic evidence of definite anterior myocardial infarction (93% of 28 patients), than in those who showed definite electrocardiographic evidence of anterior myocardial infarction (66% of 38 patients).it is concluded that severe occlusive left anterior descending coronary artery disease with anterior wall myocardial asynergy is usually associated with electrocardiographic signs of anterior myocardial infarction, whereas equally severe left anterior descending coronary artery disease without anterior wall asynergy is rarely associated with electrocardiographic abnormalities of anterior myocardial infarction. Severe left anterior descending coronary artery obstruction without electrocardiographic and angiographic evidence of anterior myocardial infarction is usually associated with collateral circulation to the left anterior descending coronary artery and collateral circulation to the left anterior descending coronary artery is present less frequently when obstruction is associated with anterior myocardial infarction.     

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.     

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.     

A natural history study of the prognostic role of coronary arteriography

Coronary cinearteriograms, clinical records, and left ventriculograms of 304 patients studied for evaluation of chest pain were reviewed. Clinical and follow-up data on survival of the normal subjects and the nonoperative group with abnormal arteriograms are presented.Ninety-two per cent of patients with typical angina pectoris had serious coronary occlusive disease. Ninety-eight per cent of patients with relatively normal coronary arteriograms survived for one to 60 or more months (mean follow-up period 24 months).There was a high mortality rate when the left main coronary artery was involved (47 per cent) and when the left coronary anterior descending branch was seriously occluded (28 per cent when arteriographic scores were high and 14 per cent when total scores were low) and a low mortality rate (0 to 7 per cent) when the LAD was normal. Mean follow-up interval in these groups was 19 months.The mortality rate was nearly three times greater when patients had QRS changes on ECG of prior myocardial infarction and six times greater when left ventricular contraction was significantly impaired.     

Reappearance of anterior QRS forces after coronary bypass surgery: An electrovectorcardiographic study

This report describes the reappearance of anterior QRS electrical forces in six patients after direct coronary arterial bypass surgery. Each patient had severe coronary artery disease including a segmental stenosis of the left anterior descending artery. Revascularization was performed by direct anastomosis of the left Internal mammary artery to the left anterior descending coronary artery and saphenous vein bypass of other stenotic coronary arteries. Preoperative electrocardiograms and vectorcardiograms showed patterns of anterior wall myocardial infarction with absent or diminutive anterior QRS forces. In each case, postoperative studies demonstrated the regeneration of anterior QRS forces within 10 days of operation. Although these patients represent a small percent of those with a preoperative pattern of infarction who undergo coronary revascularization, the findings demonstrate that electrically silent areas of myocardium may be altered and are not always synonymous with myocardial cell death. Chronic myocardial ischemia may in certain instances produce electrocardiographic and vectorcardiographic patterns of myocardial infarction that may be reversible upon reestablishment of perfusion to ischemie areas.     

Ischemic myocardial injury during coronary artery surgery

ECG's and serum levels of SGOT, LDH, and CPK were examined during the postoperative period in 50 patients with angina pectoris who had myocardial revascularization procedures. ECG signs of acute myocardial infarction appeared in 34 per cent and changes compatible with acute ischemic injury were seen in 10 per cent. Elevation of SGOT exceeding 90 units occurred in 32 per cent of 50 patients, and LDH levels over 900 units occurred in 24 per cent. In patients with ECG evidence of post-operative infarction or ischemia, 50 per cent had abnormal SGOT levels and 55 per cent had abnormal LDH levels. In 16 patients with SGOT levels exceeding 90 units, 69 per cent had ECG evidence of acute infarction or ischemia. Two patients died following surgery and acute myocardial infarction was demonstrated in both at autopsy. Relief of angina occurred in one patient who developed a myocardial infarct following internal mammary implantation. A follow-up angiogram revealed no effective communication of the implant with myocardial vessels. Acute myocardial infarction is a frequent complication of coronary artery surgery as determined by serial ECG's. In this study, approximately 50 per cent of these patients had diagnostic elevations of SGOT or LDH.     

The role of intra-aortic balloon pump in the management of patients with main left coronary artery disease

Seventy-five patients with ≥70% stenosis of the left main coronary artery (LMCA) were treated surgically between January 1974 and February 1980. The group consisted of 57 men and 18 women with a mean age of 62.8 years. All patients were symptomatic with angina pectoris, and 64 (85%) had unstable angina. Twenty-nine patients (38.6%) had electrocardiographic evidence (ECG) of old myocardial infarction (MI) and only six (8%) had a normal resting ECG. Preoperative exercise testing was done in 22 of the 75 patients. The stress test was positive in all patients, 17 (77%) of whom had > 2 mm ST depression; 90.6% (68/75) had significant right coronary artery disease. The intra-aortic balloon pump (IABP) was inserted preoperatively in only four patients (5%) and was required in two additional patients postoperatively. The IABP was inserted preoperatively in four patients because of medically refractory angina and not on the basis of coronary anatomy alone. An average of three grafts per patient were inserted. There were three (4%) postoperative myocardial infarctions and two (2.6%) deaths. During the follow-up period, which comprised 105 patient-years, there was one myocardial infarction and one death. These data indicate that successful surgical treatment of left main coronary artery disease can be achieved with low mortality and that routine preoperative insertion of IABP is unnecessary.     

Recognition of myocardial infarction after cardiac surgery and its relation to cardiopulmonary bypass

The incidence of operatively related acute myocardial infarction in patients undergoing coronary artery bypass surgery and open-heart surgery was determined and compared. Elevation of at least two enzymes, SGOT > 200, LDH > 400, and CPK > 800, was noted in patients with myocardial infarction (P < 0.05). The overall incidence of infarction was 17 per cent, and there was no significant difference in frequency of infarction in the two groups. Inferior myocardial infarction was the most common locus of damage. All patients developing myocardial infarction in the coronary bypass surgery group had evidence of generalized coronary artery disease. Infarction most frequently developed in patients requiring multiple vessel bypasses. Lesions of the left main coronary artery seem to be critical. The cardiopulmonary bypass pump time was 33 per cent longer in patients sustaining myocardial infarction, a statistically significant difference (P < 0.02). Age, sex, arrhythmias, congestive heart failure, serum cholesterol, or uric acid levels appeared not to be related to the development of postsurgical myocardial infarction in these cases. These data indicate that myocardial infarction is common both after coronary bypass surgery and open-heart surgery, and that the incidence rises with the more difficult and longer operations.     

Predictive value of electrocardiographic patterns in localizing left ventricular asynergy in coronary artery disease.

Transmural myocardial infarction by ECG (ECG-MI) was correlated with left ventricular asynergy by biplane left cineventriculography in 200 patients with coronary artery disease. The ability of individual ECG-MI patterns to predict and correctly localize asynergy was: anterior--98 per cent (43 of 44), inferior--82 per cent (36 of 44), true posterior--73 per cent (11 of 15). Of various combinations of criteria for true posterior ECG-MI, the pattern of an R wave and upright T wave in Lead V1 was most predictive of posterior asynergy--80 per cent (8 of 10). The LAO projection demonstrated a wall motion abnormality not appreciated in the RAO in 8 per cent (10 of 122) of cases of inferoposterior asynergy and enhanced assessment of asynergy in 30 per cent (36 of 122) of cases. It is concluded that: (1) ECG-MI has a high predictive accuracy for left ventricular asynergy, (2) an R-wave and upright T wave in Lead V1 is the best ECG predictor of posterior asynergy, and (3) the LAO projection makes an important contribution to the assessment of regional asynergy in coronary artery dieseas.     

Predictors of myocardial contractile recovery after coronary revascularization in patients with prior myocardial infarction

BackgroundWe sought to explore the prognostic power of certain patient characteristics to predict myocardial contractile recovery after coronary revascularization in patients with prior myocardial infarction.Methods and MaterialsWe enrolled 100 consecutive patients with prior myocardial infarction, significant coronary stenosis/occlusion amenable for revascularization, and regional wall motion abnormality in the distribution of the affected artery. All patients underwent echocardiographic assessment of regional wall motion and left ventricular ejection fraction. Patients underwent coronary revascularization by either percutaneous angioplasty or surgical bypass. Echocardiography was repeated 8 weeks following revascularization. Patients were classified into two groups: Group 1 with evidence of contractile improvement after revascularization at follow-up echocardiography and Group 2 with no such evidence of improvement. The two groups were compared with respect to patients' clinical characteristics and echocardiographic and angiographic data.ResultsPredictors of contractile recovery after revascularization included angina pectoris, the shorter age of infarction at the time of revascularization, a higher baseline left ventricular ejection fraction, a lower baseline wall motion score index, the presence of Grade 2–3 collaterals to the infarct-related artery, and the absence of dyspnea or diabetes mellitus. Stepwise regression analysis identified the presence of Grade 2–3 collaterals to the infarct-related artery and the age of infarction at the time of revascularization as independent predictors of contractile recovery after revascularization.ConclusionsIn patients with prior myocardial infarction, the presence of Grade 2–3 collaterals to the infarct-related artery and the shorter age of infarction at the time of revascularization independently predicted myocardial contractile recovery after coronary revascularization.     

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.     

Myocardial perfusion imaging with 99mTc or 113mIn macroaggregated albumin: Correlation of the perfusion image with clinical,angiographic, surgical,and histologic findings

Scintillation camera myocardial perfusion images were performed in 77 patients with proved or suspected ischemic heart disease following the intracoronary injection of 1.5 mCi ^99mTc or ^113mIn macroaggregated albumin. Perfusion images were classified as normal (36) or abnormal (41), and the location of abnormality was noted. Thirty-seven out of 41 patients with abnormal images had prior myocardial infarction based on history (30), ECG Q-waves (27), local contraction pattern abnormality (23), or direct surgical (9) or histologic (4) inspection, either singly or in combination. Three out of five patients with pre-infarction angina had image defects-none had evidence of infarction by ECG, ventriculogram, or surgical inspection. Coronary artery stenosis correlated with image defects to the extent that myocardial infarction was associated; 28 out of 29 patients with total occlusions and other evidence of infarction had image defects, four patients with complete occlusions but without other evidence of infarction had normal images.We conclude that, excepting patients with pre-infarction angina, this technique is more sensitive and direct in the identification of myocardial scar than standard ECG, clinical evaluation, or biplane left ventriculography.