Subtotal Stenosis Research Articles

Malignant restenosis after primary successful excimer laser coronary angioplasty

In a series of 20 coronary excimer laser angioplasties, two patients presented with a peculiar type of malignant restenosis 6 and 8 weeks after a successful laser angioplasty procedure. One patient had a successful recanalization of an occluded left anterior descending (LAD) coronary artery and the second patient had a successful angioplasty of a subtotal proximal stenosis of the left anterior descending coronary artery. After the procedure, no ischemia could be demonstrated by exercise ECG and thallium scintigraphy. Both patients were free of angina until the sudden development of nocturnal angina several hours before reangiography, which showed subtotal restenosis in both cases. One patient had a mammaria graft on the LAD and the second patient underwent a successful balloon angioplasty. This uncommon sudden and malignant development of restenosis seems to be related to the excimer laser angioplasty procedure and warrants some caution with the indiscriminative use of this new angioplasty procedure.

Advances in Interventional Cardiology

The field of interventional cardiology is growing widely. This growth is the result of improvements in existing technology, development of new technology, and expansion of criteria for the selection of patients. Percutaneous transluminal coronary angioplasty (PTCA) remains the mainstay and is used to treat an increasing number of patients with coronary artery disease that manifests as stable or unstable angina or acute myocardial infarction. Atherectomy is being used to "debulk" lesions and remove atheromatous plaque as well as to remove intimal flaps after PTCA. The insertion of an intracoronary stent is a strategy designed to treat intimal dissections and acute closure as well as to attempt to decrease the incidence of restenosis. Finally, intracoronary laser therapy--independently or in combination with PTCA--is being evaluated as a treatment approach for more diffuse disease, acute occlusion, and prevention of restenosis.

Reinfarction Related to PTCA‐Induced Coronary Embolism after Successful Thrombolytic Therapy

Coronary embolism originating from residual thrombotic material is one of the complications arising during acute percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction. This case report describes a symptomatic embolization of the right posterolateral and right posterior descending branch during success‐ful PTCA of a subtotal stenosis of the midright coronary artery after acute inferior myocardial infarction. Typical ECG signs of reinfarction were recorded. We succeeded in recanalizing these branches by superselective thrombolysis and angioplasty.

Effects of thrombolytic therapy in unstable angina: Clinical and angiographic results

The incidence of intracoronary thrombus and the effects of thrombolytic therapy were studied in 41 patients with unstable angina. All patients underwent coronary angiography 2 to 69 h (mean 19) after their last attack of chest pain. Immediately after angiography, 21 patients received intracoronary streptokinase (250,000 IU in 45 min) and were retrospectively analyzed. Twenty patients received intravenous recombinant tissue-type plasminogen activator (rt-PA) (100 mg in 3 h) and were involved in a prospective study.Eleven of the 21 patients from the streptokinase group and 11 of the 20 patients from the rt-PA group showed a decrease in the severity of the coronary stenosis on repeat angiography 1 day later. A decrease in coronary obstruction was primarily observed in 10 of 13 patient; with a complete stenosis and in 6 of 9 patients with a subtotal stenosis and markedly diminished coronary flow. Improvement in coronary anatomy was not determined by the clinical characteristics of the patients. Twenty-eight of the 41 patients had angiographic evidence of intracoronary thrombus formation before and 16 had such evidence after thrombolytic treatment. Nine patients developed a small increase in serum cardiac enzymes before or during treatment. Ischemic symptoms and the incidence of surgical or angioplastic intervention were not different in patients with or without a reduction in coronary artery stenosis after fibrinolytic therapy.These observations suggest a high incidence of coronary thrombosis in patients with unstable angina. The data do not permit assessment of the clinical therapeutic efficacy of thrombolylic therapy. Better risk stratification and placebo-controlled prospective studies are required to obtain information on the risk/benefit ratio of such therapy in unstable angina.

Interventional cardiology—An overview

Unt i l 10 years ago, cardiac catheterization was predominantly a diagnostic tool for defining anatomic and functional disease states before cardiac surgical correction. After a decade of tentative exploration with the fixed rigid dilator technique of Dotter, balloon dilatation was developed by Andreas Gruentig in 1974 as a treatment for peripheral atherosclerotic stenosis, ushering in the new field of cardiology. The current supplement to the American Journal of Cardiology is based on a symposium that was sponsored by Advanced Cardiovascular Systems in June 1987 to assess the status of this important new field in which the cardiac catheter is used to render definitive treatment of cardiovascular disease, as well as to provide diagnostic data. The centerpiece of interventional cardiology today is percutaneous transluminal coronary angioplasty (PTCA). During the early years of PTCA (1977 through 1981), relatively crude devices and inexperienced operators limited PTCA to patients with proximal, discrete, subtotal stenosis of a single coronary artery (who comprised only 5 to 10% of the population requiring coronary revascularization), and to a primary success rate of only 60%. In contrast, coronary angioplasty is now being applied routinely to patients with more complex coronary anatomic situations, including distal disease, stenosis of multiple vessels, bifurcation lesions, total occlusions, and diseased saphenous vein or internal mammary artery bypass grafts. Concomitant with this expansion in the anatomic capabilities of coronary angioplasty has been a marked broadening of its clinical indications, which now include patients with chronic stable angina, unstable angina, acute myocardial infarction, clinical features that make bypass surgery unacceptable, and a small subgroup of

Symptomatic coronary-subclavian steal corrected by carotid-subclavian bypass

Angina recurred after a left internal mammary-to-left anterior descending coronary artery bypass graft. Subsequent development of a subtotal stenosis in the proximal left subclavian artery caused reversal of flow in the patent internal mammary artery graft, which produced an angiographic steal of myocardial perfusion. Angina and ischemia were relieved by reoperation, which consisted of left common carotid-to-left subclavian artery bypass in conjunction with right internal mammary-to-right coronary artery bypass and aorto-to-lateral circumflex coronary artery bypass with reversed saphenous vein.

Duplex carotid sonography: criteria for stenosis, accuracy, and pitfalls.

Both carotid bifurcations were examined in 353 patients over a 20-month interval using a combination of real-time and pulsed Doppler ultrasound (duplex scanning). Angiographic correlation was available in 72 cases. Stenosis of the internal carotid was evaluated using a Doppler input frequency of 5 MHz and a scan angle of 60 degrees. A peak frequency shift of less than 3.5 kHz was found to be a sign of less than or equal to 30% stenosis; 3.5-4 kHz with moderate turbulence suggested 31-50% stenosis, 4-8 kHz 51-90% stenosis, and greater than 8 kHz greater than 90% stenosis. Subtotal stenosis (greater than 95%) was manifested by a frequency shift of less than 8 kHz, but the waveform was totally distorted. Overall accuracy improved from 77% for the first 6 months to 87% for the last 14 months. For stenosis greater than 50%, sensitivity improved from 82% to 97% during this period. Analysis of errors and suggestions for avoiding them are presented.

Return of left ventricular function after reperfusion in patients with myocardial infarction: importance of subtotal stenoses or intact collaterals.

To determine whether subsequent improvement in left ventricular ejection fraction can be predicted from preintervention coronary arteriograms, we divided 63 patients with acute myocardial infarction into two groups based on findings at emergency coronary arteriography at a mean of 7 hr after onset of symptoms: (1) a "no-flow" group with an occluded infarct-related artery and no easily visible collaterals (n = 36) and (2) a "limited-flow" group with either subtotal stenosis or total occlusion of the infarct-related vessel with intact collaterals (n = 27). Of the 63 patients, 61 underwent emergency procedures to establish reperfusion. At follow-up angiography (contrast or radionuclide) performed 12 +/- 7 days after infarction, global ejection fraction had increased significantly in patients with limited flow to the infarct zone and "successful" early reperfusion intervention due primarily to a significant increase in the regional ejection fraction in the infarct zone. Global ejection fraction fell significantly between baseline and follow-up in patients with no flow to the infarct zone and "unsuccessful" early reperfusion intervention due primarily to a fall in the regional ejection fraction of the noninfarct zone. Global and regional ejection fractions did not change significantly in patients with no flow to the infarct zone and successful early reperfusion or in patients with limited flow to the infarct zone and unsuccessful early reperfusion intervention. The elapsed time before reperfusion did not relate significantly to the change in either regional or global ejection fraction. However, the magnitude of improvement in both global and regional ejection fraction at follow-up was greater among patients with anterior infarcts than among those with inferior infarcts, possibly because baseline ejection fraction was lower in patients with anterior infarcts. These data indicate that among patients with acute myocardial infarction undergoing emergency coronary arteriography at a mean of 7 hr after onset of symptoms, improvement in global ejection fraction is unlikely to occur even after a successful early reperfusion intervention in the absence of preserved flow to the infarct area. However, among patients with subtotally occluded infarct-related arteries or significant collateral blood flow to the infarct zone, subsequent improvement in global and regional ejection fraction in the zone of myocardial infarction frequently occurs. Improvement in both global and regional ejection fraction may be more readily demonstrated in patients initially having more severe depression of these parameters.

Follow-up of patients from the Coronary Artery Surgery Study (CASS) potentially suitable for percutaneous transluminal coronary angioplasty

To determine the proper place for percutaneous transluminal coronary angioplasty (PTCA) among the therapeutic options available for patients with coronary heart disease, one must compare the results of PTCA with those obtained by conventional medical and surgical therapy. To develop a cohort comparison group, we interrogated the Coronary Artery Surgery Study (CASS) registry, and patients with proximal discrete subtotal stenosis (70% to 99%) involving the right, left anterior descending, circumflex, or left main coronary artery, singly or with stenoses in two of the three major coronary arteries, were selected; 796 patients (3.7% of all patients enrolled in CASS from 1975 to 1979) met these selection criteria. Surgical therapy was chosen in 53.3%; surgical mortality was low and there was excellent 4-year actuarial survival. There was significant improvement in functional class. Survival was also excellent in medically treated patients. Medically treated patients also had significant improvement in functional class in comparison with baseline values. The data prosented here characterize a cohort group against which the clinical results of PTCA can be evaluated and compared.

Natural history of patients with single-vessel disease suitable for percutaneous transluminal coronary angioplasty

To permit comparison of percutaneous transluminal coronary angioplasty (PTCA) with conventional therapy, the clinical outcome was established in patients who would have been suitable candidates for PTCA but who presented before the technique was available. Coronary angiograms were reviewed of patients who met the following criteria: single-vessel disease with proximal subtotal coronary stenosis, chest pain of at least class II, and cardiac catheterization before 1981. Angiograms were evaluated according to established criteria for PTCA by an experienced angiographer. One hundred ten patients (2.1% of the patient population) were judged suitable for PTCA. Clinical and catheterization findings closely resembled those of patients in the national PTCA registry. Five years after catheterization, 97% of PTCA candidates treated medically were alive and 85% had not had myocardial infarction. Forty-six patients had coronary artery bypass surgery within 6 months of catheterization and 10 other patients had subsequent surgery. Five years after surgery, 91% were alive and 87% had not had myocardial infarction. At 6 months of follow-up, 78% of all patients had improved at least 1 functional class, and 86% of all patients working before catheterization were still employed. Functional capacity was well maintained during long-term follow-up (median 6.5 years, range 1.4 to 12.2). These data indicate that PTCA candidates have an excellent prognosis for survival, a low risk of infarction, and well-maintained functional capacity when revascularization is reserved for those with inadequate control of symptoms by medical therapy.

Myocardial lactate metabolism during pacing induced angina pectoris

Myocardial lactate metabolism was studied in 20 patients with coronary heart disease during and immediately after slight angina pectoris induced by atrial pacing. Myocardial lactate extraction ratio (MLE) decreased from 0.27 +/- 0.03 (SEM) before angina to 0.01 +/- 0.06 during angina, and further to -0.32 +/- 0.11 at 15 sec after pacing. Lactate production was found to occur in eight patients during pacing and 13 patients after pacing. Cardiac venous flow was measured by thermodilution in eight of these patients. 'Net ischaemic lactate efflux' increased by 23 +/- 4 mumol/min 15 sec after pacing, whereas 'lactate uptake in non-ischaemic regions' diminished by 11 +/- 2 mumol/min. Lactate production 15 min after pacing was revealed in all patients with subtotal stenosis of the left anterior descending coronary artery (LAD), whereas it was less frequently observed in patients with occluded LAD and collaterals to the post-stenotic area. Increased washout of metabolites from the ischaemic myocardium during the early recovery period is the main reason for the rather high sensitivity of ischaemia detection by this procedure. This permits shorter pacing periods and less pain than in earlier studies. Both MLE and electrocardiographic changes were equally reproducible after 20 and 45 min recovery period.

Percutaneous transluminal coronary angioplasty immediately after intracoronary streptolysis of transmural myocardial infarction.

Percutaneous transluminal coronary angioplasty (PTCA) was performed in 21 patients with acute myocardial infarction (AMI) treated by intracoronary infusion of streptokinase within 8 hours after the onset of symptoms. Streptolysis therapy began a mean of 3.6 +/- 1.2 hours (+/- SD) after the onset of symptoms. The vessel was occluded in 14 patients and highly stenosed in seven. After the infusion of 67,300 +/- 63,200 IU of streptokinase over 26.1 +/- 21.5 minutes, patency of the occluded vessels was reached. PTCA as performed 20-60 minutes after the end of streptokinase treatment in 19 patients and 24 and 31 hours after treatment in two patients. The dilation was successful in 17 patients (81%). The degree of vessel obstruction was reduced from 90.2 +/- 7.3% to 58.6 +/- 19.5% (area method) and from 71.4 +/- 12.4% to 39.2 +/- 19.7% (diameter method). The improvement was 31.5 +/- 18.4% and 32.2 +/- 19.3%, respectively. No reocclusion was induced by PTCA. Twenty patients were discharged. One died during hospitalization; at autopsy, the treated vessel was still patent. During the follow-up period, two reinfarctions and one asymptomatic reocclusion occurred. The clinical findings during the hospital course and the follow-up period were compared with those of a control group of 18 patients with AMI and comparable coronary stenoses who were treated only with streptokinase infusion. Four of these patients had a reinfarction during the hospital course, and three died during the follow-up period. PTCA can be performed safely and successfully immediately after intracoronary infusion of streptokinase in patients with AMI. By reducing the subtotal stenosis, this treatment contributes to the reperfusion of the ischemic myocardium, diminishes the risk of a reocclusion and seems to improve the prognosis.

Experience with intracoronary streptokinase in 36 patients with acute evolving myocardial infarction.

Acute angiography was performed in 36 consecutive patients with evolving myocardial infarction admitted within 3 h after onset of symptoms. No fatal complication occurred. Angiography revealed a total occlusion in 32 patients (89%), a subtotal stenosis in three (8%), and a 90% stenosis in one patient (3%). Anterior infarction was exclusively related to left anterior descending, and inferior infarction to right coronary or circumflex obstruction. After identification of the ‘infarct-vessel’, nifedipine 10 mg was administered sublingually. In no patient was anterograde flow affected with this treatment. In 35 patients an attempt to lyse clot was made with intracoronary streptokinase; an infusion of 2000–4000 U/min, preceded by a bolus of 10 000–20 000 U was infused into the ‘infarct-vessel’. In 26 patients (74%) reperfusion was achieved, two combined with guidewire perforation. The mean duration of onset of symptoms to reperfusion was 3.6 h (range 1.8–5.6). The mean duration of lysis was 1.2 h (range 0.3–3), and the mean dosage of streptokinase was 200 000 U (50 000–400 000 U]. In 25 out of 26 patients (96%) a high degree of obstruction remained immediately after lysis and at repeat angiography 6–8 weeks after the acute event. Despite treatment with aspirin 200 mg daily and nifedipine 30 mg daily four re-occlusions occurred. Coronary bypass surgery was performed electively in five patients. Thus, we conclude that in patients with evolving myocardial infarction, the infarct-vessel can be recanalized in 74% of patients by intracoronary streptokinase. The true benefit of this treatment must await a controlled study.

Angiographic findings 1 month after myocardial infarction: a prospective study of 259 survivors.

Coronary anatomy as it relates to left ventricular function was assessed prospectively in patients who survived acute myocardial infarction. The study population included 259 consecutive male patients age 60 years or younger who underwent catheterization 30 days after the acute event. Coronary artery obstructive lesions (greater than 50% reduction in luminal diameter) were found in 241 patients (93%), 118 (45%) of whom had total and 76 (29%) subtotal (greater than 90%) stenosis) occlusion of at least one coronary artery. Normal coronary vessels were seen in eight patients (3%) and nonobstructive lesions in 10 (4%). One-, two- and three-vessel disease were present in 89, 86 and 66 patients, respectively. Patients with normal coronary arteries or nonobstructive lesions had higher ejection fractions than those with obstructive lesions in one, two or three vessels (p less than 0.05). Ejection fraction was lower (p less than .001) and the percentage of akinetic segments higher (p less than 0.001) in patients with total or subtotal lesions and no collaterals. Adequate collaterals, seen in 29 patients (11%), significantly improved regional wall motion (p less than 0.05) and decreased the percentage of akinetic segments (p less than 0.001). Thus, in a substantial number of patients (32% in our series), the infarcted area is spontaneously reperfused by collaterals or through the involved artery. Both mechanisms ameliorate wall motion in corresponding areas.

Total occlusion of the left main coronary artery: The Coronary Artery Surgery Study (CASS) experience

Total occlusion of the left main coronary artery was confirmed on review of the coronary angiograms in 12 (0.06 percent) of the 20,197 patients entered into the Coronary Artery Surgery Study (CASS) before coronary arterial surgery. Clinical features alone could not distinguish the patients with total occlusion of the left main coronary artery from those enrolled in the CASS with subtotal stenosis of this vessel. The right coronary artery had a stenosis greater than or equal to 70 percent of luminal diameter in 7 of the 12 patients. Collateral flow to the left coronary artery was defined as “substantial” or “limited” based on the presence or absence of clear visualization of the main channel of either the left anterior descending or left circumflex coronary artery during coronary angiography. Of the eight patients with “substantial” collateral flow, one (13 percent) had an aneurysmal or dyskinetic left ventricular wall segment, whereas all (100 percent) of the three patients with “limited” collateral flow had dyskinesia or an aneurysm (p < 0.05). Seven patients underwent coronary bypass graft surgery; 6 (86 percent) of these patients were living at their most recent follow-up, a mean of 46 months after entry into the CASS. Two of these patients continued to have angina pectoris. Five patients did not undergo coronary bypass grafting and 2 (40 percent) were still alive at their most recent follow-up, a mean of 45 months after entry into the CASS. One of these patients had angina pectoris. The difference in survival between the medical and surgical groups was not statistically significant.This study indicates that patients with total occlusion of the left main coronary artery are uncommon and cannot be distinguished by presenting features alone from patients having subtotal stenosis of the left main coronary artery. “Substantial” coronary collateral blood flow is associated with better left ventricular wall motion than is “limited” collateral flow. Prolonged survival and lessening of symptoms may occur after coronary bypass grafting although long-term survival is possible without it.

Improvement of left ventricular function after percutaneous transluminal coronary angioplasty

Cardiac function and left ventricular dynamics were measured in seven consecutive patients 1 day before and 6 months after percutaneous transluminal balloon angioplasty of subtotal proximal stenosis of the left anterior descending coronary artery. Before angioplasty all patients had obvious left ventricular dysfunction during exercise and to a smaller degree during isoproterenol infusion; the condition of all patients was greatly improved 6 months after angioplasty. After angioplasty, left ventricular end-diastolic pressure was normal at rest and decreased from a mean (± standard error of the mean) of 33.8 ± 1.6 to 19.2 ± 0.5 mm Hg on exercise. Left ventricular ejection fraction, measured by a gated blood pooling technique with technetium-99m, improved on exercise from 46 ± 5.0 percent to 69 ± 1.0 percent. Cardiac output and stroke volume index increased significantly with exercise after angioplasty. The peak negative rate of pressure reduction in the left ventricle (dP/dt/min), an index of left ventricular relaxation, was highly abnormal on exercise before (2,307 ± 260 mm Hg/s) and increased to the normal range (3,154 ± 200 mm Hg/s) after angioplasty. The improvement in left ventricular function after transluminal angioplasty in these cases of proximal left anterior descending coronary arterial stenosis is extremely encouraging.

Management of evolving myocardial infarction by intracoronary thrombolysis and subsequent aorta-coronary bypass

From February, 1980, through May 1, 1981, nonsurgical recannulation of acutely thrombosed coronary arteries by selective intracoronary infusion of streptokinase and plasminogen was attempted in 72 patients in our institution. All patients were admitted to the hospital within 4 hours after the onset of symptoms of acute myocardial infarction, and in all patients significant electrocardiographic changes were noted. Re-establishment of orthograde coronary blood flow was achieved in 56 patients. The overall mortality was 13% (9/72 patients). Twenty patients (28%) required early surgical coronary revascularization because of persistent subtotal stenosis, intermittent severe coronary spasm, or unstable angina. Six patients (8%) presented with a history of previous myocardial infarction. One patient had a large anterior left ventricular aneurysm and another patient had significant mitral valve disease, both of which were treated surgically concomitantly with coronary revascularization. Seven patients received single aorta-coronary bypass grafts, nine patients received double grafts, two patients received triple grafts, and two patients received quadruple grafts. The mean interval between thrombolysis and aorta-coronary bypass was 3.9 days. Six patients underwent operation within 8 hours of thrombolysis. There were no early deaths, but there was one late sudden death 4 months after operation and there was one instance of reinfarction owing to severe coronary spasm in the presence of graft occlusion. Seventeen of 20 patients undergoing operation were restudied angiographically. The overall graft patency rate was 81%. Left ventricular ejection fractions, calculated from the right anterior oblique projection of the left ventricular angiogram, increased from 42% at the time of intracoronary lysis to 55% at the time of restudy. Early aorta-coronary bypass may be safely combined with successful thrombolysis using selective intracoronary streptokinase with plasminogen in the setting of acute myocardial infarction, and early operation may be useful in preventing reocclusion of the previously thrombosed vessel.

Anterior left ventricular wall circulation in patients with coronary artery disease

The human anterior left ventricular circulation was investigated at rest and during submaximal atrial pacing by measuring the great cardiac venous blood flow by the constant infusion thermodilution method. Forty-seven patients with angina pectoris participated in the study and were grouped stepwise according to degree of arteriosclerosis in the left anterior descending coronary artery (LAD), from normal to occluded vessel. Special attention was paid to patients with earlier infarcts and to collateral circulation. Blood flow to the myocardium was slightly but significantly reduced only among patients with a subtotal stenosis of the LAD without demonstrable collateral circulation, and only during atrial pacing. This conforms with an increased coronary arteriolar resistance in these patients. Myocardial oxygen extraction was, however, increased in all groups of patients with LAD stenosis from 50% to occlusion, except in patients with an earlier anterior wall myocardial infarction. This suggests a disproportion between oxygen demand and blood flow leading to increased extraction in patients without infarcts and a shunting of blood through scarred myocardium with a low oxygen demand in those with a previous necrosis, and is confirmed by a decreased ratio between myocardial flow and cardiac work. Patients with an increased oxygen extraction may benefit from coronary bypass surgery to the LAD area while those without may not.

Postoperative stroke and late neurologic complications after carotid endarterectomy.

From 1969 through 1973, 335 consecutive patients (mean age, 60 years) underwent 390 carotid endarterectomies using hypercarbic general anesthesia and no carotid shunting. Early neurologic complications were most common among patients with previous neurologic symptoms and among those with subtotal stenosis or occlusion of the contralateral internal carotid artery. The introduction of routine carotid shunting without hypercarbia during a subsequent series of 626 procedures from 1974 through 1978 has been associated with significantly fewer operative strokes in comparable groups of patients. Complete follow-up information during a mean interval of 8.6 years is available for 95% of 325 operative survivors. Late completed strokes have occurred in 17% of patients but have involved the cerebral hemisphere on the side of previous carotid endarterectomy in only 7%. Of 93 operative survivors who had subtotal stenosis of the contralateral internal carotid artery, 45 underwent contralateral endarterectomy as an elective procedure and 48 did not. The late contralateral stroke rates for these two groups of patients were 4% and 16%, respectively, although these differences did not attain statistical significance. Forty-nine (78%) of 63 patients with contralateral internal carotid occlusion have had no late neurologic symptoms following unilateral carotid endarterectomy.

Changes in coronary anatomy and left ventricular function from the acute to the chronic stage of myocardial infarction.

Coronary angiography was performed in the acute stage of myocardial infarction in 65 patients. The infarct-related vessel was occluded in 50 patients; it was narrowed greater than 90% in the remaining 15 patients. Control angiography was performed 55 +/- 46 d after acute myocardial infarction in 18 patients. In the chronic stage, five of thirteen previously occluded vessels showed antegrade filling of the distal segment. The narrowing at the site of previous obstruction was 80--95%. In two of five patients with a subtotal stenosis, the lumen of the infarct-related vessel was clearly larger in the chronic stage. The end-diastolic volume index increased significantly from 86 +/- 23 ml/m2 in the acute stage to 110 +/- 35 ml/m2 in the chronic stage (p less than 0.001). The increase in the end-systolic volume index from 42 +/- 15 ml/m2 to 63 +/- 31 ml/m2 was also statistically significant (p less than 0.005). Stroke volume index, ejection fraction, and the length of the akinetic segment (AKS) did not change significantly. There was a weak correlation between the end-systolic volume index and the length of the AKS in the acute stage (r = 0.489, p less than 0.05) and a better correlation in the chronic stage (r = 0.602, p less than 0.01). The ejection fraction and the length of the AKS correlated in the chronic stage only (r = 0.795, p less than 0.001).