Diagnostic value of electrocardiogram and vectorcardiogram in postinfarction ventricular asynergy

The ability of ECG-VCG to predict the severity of postinfarction LV asynergy was evaluated in 152 patients with previous myocardial infarction who underwent left cineventriculography in the right anterior oblique view. Various ECG and VCG signs were examined in order to predict the existence of severe asynergy in general (dyskinesia or akinesia or severe hypokinesia) and of dyskinesia in particular. In patients with inferior myocardial infarction (Group A) persistent ST segment elevation was the only specific ECG sign (100%) of severe asynergy; it had a poor sensitivity (6.2%). Four frontal VCG signs (presence of terminal bite, y- greater than 0.18 mV, maximum early superior vector along x axis = MESV greater than or equal to 1.3 mV, duration of initial superior forces = DISF greater than 50 msec) increased the sensitivity of the ECG-VCG method to 75.8% while maintaining a 100% specificity. Regarding the diagnosis of dyskinesia, only the ECG sign of persistent ST segment elevation and the VCG sign of y- greater than or equal to 0.3 mV had a 100% specificity. The sensitivity of the ECG-VCG method was 33.3% (16.6% ECG and 16.6% VCG). In patients with anterior myocardial infarction (Group B), concerning the diagnosis of severe asynergy, the ECG signs of sigma ST greater than 3 mm in anterior leads; pathologic Q wave in four or more anterior leads (including D1 and aVL); and the presence of LAH or LAH + RBBB, had a 100% specificity and a good sensitivity (60.5%). The VCG sign of a narrow horizontal QRS loop increased the sensitivity of the ECG-VCG method to 71% while maintaining a 100% specificity. As for the diagnosis of dyskinesia, the ECG signs with a 100% specificity were sigma ST greater than or equal to 5 mm in anterior leads, a pathologic Q wave in more than five anterior leads (including I and a VL) and RBBB + LAH; these variables had a sensitivity of 48.3%. The VCG sign of a narrow horizontal QRS loop increased the sensitivity of the ECG-VCG method to 79.3% while maintaining a 100% specificity. In patients with inferior plus anterior myocardial infarction (Group A + B) the signs mentioned above for each group were evaluated, confirming a 100% specificity. Regarding the diagnosis of severe asynergy, the ECG signs had a sensitivity of 61.3%, while VCG increased the sensitivity of the ECG-VCG method to 90.3%.(ABSTRACT TRUNCATED AT 400 WORDS)     

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.     

Clinical and hemodynamic aspects of single vessel coronary artery disease

Two-hundred consecutive patients with arteriosclerotic heart disease underwent complete clinical and hemodynamic evaluation. Fifty-two patients (26 per cent) had significant single vessel coronary artery disease and were compared to 148 patients with more extensive coronary artery disease and to a group of 14 normal patients. The single vessel disease group, when compared to the diffuse disease group, was characterized by a shorter duration of angina pectoris, lower frequency of a history of congestive heart failure or cardiomegaly, and a lower frequency of electrocardiographic (ECG) evidence of a transmural myocardial infarction. The combination of angina pectoris for three or more years with cardiomegaly was the only factor which completely separated the two coronary disease groups. Cardiomegaly, when present in single vessel involvement, was always due to left anterior descending (LAD) disease, together with an anterior infarction on ECG and left ventricular asynergy. The single vessel disease group included 32 patients with LAD disease, 17 with RCA, and 3 with circumflex artery involvement. Resting hemodynamics in these 52 patients (other than a higher left ventricular end-diastolic pressure and wall stress) were not significantly different from hemodynamics in a normal group. Patients with diffuse disease were characterized by many hemodynamic alterations and by left ventricular (LV) asynergy, when compared to the single vessel disease or normal groups. The diffuse disease group had a lower ejection fraction (EF) and an increased frequency of LV asynergy and coronary collateral circulation than did the LAD group. In the single vessel disease group LV asynergy did not correlate with the ECG. LV synergy, however, was not found in any patient in the LAD group with abnormal Q waves on ECG. The single vessel disease group included only five patients with increased end-diastolic volume (EDV) and all had LAD involvement, increased LV end-diastolic pressure, and decreased EF. The remaining 47 patients with normal LV-EDV revealed that the LAD group had abnormal pressure-volume relationships, indicating a decreased compliance of the left ventricle.     

Clinical, hemodynamic and angiographic aspects of inferior and anterior myocardial infarctions in patients with angina pectoris

Clinical, hemodynamic and angiographic findings were reviewed in 82 patients with isolated inferior, 55 patients with isolated anterior and 27 with combined inferior and anterior myocardial infarction and were compared with findings in 100 patients without electrocardiographic evidence of a prior transmural myocardial infarction. All of the 264 patients were referred and evaluated because of angina pectoris and found, on selective coronary angiography, to have coronary artery disease. There was no significant difference in the ages of the patients in each group studied. A history of heart failure, audible gallops and cardiomegaly were more prevalent in the two groups with anterior infarction (isolated and combined with inferior infarction) than in the other two groups. The mean left ventricular hemodynamic measurements (end-diastolic pressure, end-diastolic volume and ejection fraction) in the groups of patients with a normal QRS or an isolated inferior myocardial infarction were not significantly different from those of patients with a normal left ventricle. Patients with isolated anterior myocardia infarction had abnormal end-diastolic pressure (68 percent), end-diastolic volume (51 percent) and ejection fraction (67 percent). Similarly, the group with multiple infarctions had abnormal hemodynamic measurements, with 81 percent having an abnormal ejection fraction. For the entire group of patients studied, an abnormal end-diastolic volume was always associated with an abnormal ejection fraction. Cardiomegaly on X-ray film was associated with an abnormal end-diastolic volume and ejection fraction. An abnormal contractile pattern (asynergy) was noted in 42 percent of the patients with a normal QRS; inferior asynergy was observed in 88 percent with inferior infarction, and anterior or apical asynergy, or both, was found in 90 percent with anterior infarction. All the patients with multiple infarctions had asynergy. The right coronary artery was significantly involved in 90 percent of the patients with inferior infarction, while all the patients with anterio infarction had significant disease of the left anterior descending artery. More than 80 percent of the patients with an infarction pattern on electrocardiogram had double or triple vessel disease, as compared with 68 percent of the patients with a normal QRS pattern. This study represents a select group of patients referred because of angina pectoris and cannot be extended to the asymptomatic patient with coronary artery disease. The observations made on these patients indicate that an anterior infarction (isolated or combined with inferior) in patients referred because of angina pectoris is accompanied by significant impairment of left ventricular function, whereas an inferior infarction (isolated), although accompanied by asynergy, is usually associated with normal hemodynamics. The electrocardiogram is not sensitive enough to predict reliably in the individual patient the extent and severity of the coronary artery disease.     

Quantitative radionuclide angiography in the right anterior oblique view: Comparison with contrast ventriculography

Because the right anterior oblique view is widely accepted as the best “single” projection for assessing wall motion, the utility of this view during first pass radionuclide angiography was studied in 44 patients who also underwent contrast ventriculography and coronary arteriography. Of the 44 patients, 8 had a normal heart and 14 had coronary artery disease with normal wall motion on contrast ventriculography. All also had normal contraction on radionuclide angiography. On contrast ventriculography, 22 patients had coronary artery disease and asynergy involving 34 left ventricular segments. Of 17 segments localized to the anterior and apical asynergic areas on contrast ventriculography, 16 were accurately localized with radionuclide angiography. Similarly, of 17 inferior asynergic areas, 13 were also shown to be inferior on radionuclide angiography. In addition, quantitative assessment of the severity of asynergy using the hemiaxis method demonstrated a good correlation between asynergic severity as defined with radionuclide angiography and contrast ventriculography. Of 11 anterior areas, 7 defined as hypokinetic with contrast ventriculography demonstrated chordal shortening of 20.1 ± 5.2 percent (mean ± standard error of the mean) (P < 0.005 compared with normal) on radionuclide angiography. Similarly, four akinetic or dyskinetic segments on contrast ventriculography demonstrated a greater reduction (4.0 ± 4.0 percent) in chordal shortening on radionuclide angiography (P < 0.05 compared with hypokinetic segments). Akinetic apical and inferior segments as defined with contrast ventriculography also showed a marked reduction in wall motion to 10.4 ± 7.3 percent and 7.5 ± 4.1 percent, respectively.After appropriate background subtraction, determination of ejection fraction using radionuclide angiography showed a correlation of 0.839 between the left anterior oblique and right anterior oblique projections independent of the sequence of injection. In addition, ejection fraction determined with radionuclide angiography in the left (r = 0.824) and right (r = 0.801) anterior oblique views correlated well with ejection fraction assessed from contrast ventriculography. Thus, first pass radionuclide angiography performed in the right anterior oblique view is a sensitive noninvasive means of assessing the location and severity of asynergy as well as global left ventricular performance in patients with coronary artery disease.     

Asymmetric distribution of left ventricular asynergy in coronary artery disease and its relation to coronary stenoses

In 100 patients with coronary artery disease (CAD), the prevalence and severity of asynergy was determined for 9 left ventricular (LV) segments by both radionuclide and contrast angiography. The anterior, septal and lateral LV walls had significantly more prevalent and more severe asynergy in the medial segments than in the basal segments. In contrast, the inferior LV wall exhibited equally severe asynergy in both the medial and basal segments. In general, asynergy was most severe in the apical, medial septal, medial inferior and basal inferior LV segments. This asymmetric distribution of LV asynergy could not be explained by the distribution of occlusions or significant stenoses in the arterial tree, which were relatively uniformly distributed among the left anterior descending (32%), left circumflex (29%) and right (26%) coronary arteries. It is postulated instead that the asymmetric distribution of LV asynergy results from asymmetry of the coronary arterial tree supplying the left ventricle and that the prevalence of asynergy in an LV segment is directly related to its vascular distance from the coronary ostia. Unlike the relatively direct supply of the left anterior descending and circumflex arteries to the basal segments of the anterior, septal and lateral LV walls, the arterial supply to the basal inferior wall begins only after the right or dominant circumflex artery has traversed the length of the atrioventricular groove, significantly increasing its susceptibility to the pressure attenuation and occlusive jeopardy of more proximal stenoses.     

Electrocardiographic, arteriographic and ventriculographic correlations in transmural myocardial infarction

To determine if significant interrelations exist between the electrocardiographic diagnosis of transmural myocardial infarction, sites of coronary arterial obstruction, and left ventricular asynergy, 235 patients with angiographically documented coronary artery disease were subdivided according to the electrocardiographic location of the myocardial infarction, the coronary arterial system involved and the site of ventricular asynergy. Of 82 instances of anterior myocardial infarction, the left anterior descending artery demonstrated significant disease in 79 (96 percent). Of 100 instances of inferior myocardial infarction, the right coronary artery was significantly diseased in 87 and the left circumflex in 55. When multiple infarctions were present, multivessel disease was found in 93 percent of patients. Left ventricular asynergy was present in 81 percent, including 84 percent of those with anterior infarction, 74 percent of those with inferior infarction, and 93 percent of those with multiple infarctions. The results of our study suggest that the electrocardiogram is often of value in indicating sites of coronary arterial obstruction and ventricular asynergy in patients with coronary artery disease and transmural myocardial infarction.     

Noninvasively induced postextrasystolic potentiation of ischemic and infarcted myocardium in patients with coronary artery disease.

To evaluate noninvasively-induced postextrasystolic potentiation (PESP) of ischemic or apparently infarcted regions of myocardium, an external mechanical cardiac stimulator (develoepd by Zoll) was used to induce ventricular extrasystoles during M-mode echocardiography in 29 patients with coronary artery disease and in four control subjects. Twenty-five patients had > 75 per cent stenosis of the left anterior descending artery including 13 with ECG evidence of anteroseptal myocardial infarction; 21 patients had > 75 per cent stenosis of the right coronary and/or left circumflex arteries, including 11 with ECG evidence of inferior and/or posterior myocardial infarction. Twenty-four regions with reduced wall excursion showed varying effects of PESP: eight regions improved to the normal range, while 16 did not. Twelve of the latter had ECG evidence of prior infarction. Similarly, regions of asynergy that did not respond at all to PESP were usually, but not always, seen in patients with infarctions. Based on prior ventriculographic-histopathologic correlates, non-responding regions are probably totally scarred with irreversible contraction abnormalities, whereas regions with evidence of contractile reserve are potentially viable. Because the ECG and resting echocardiogram are not totally accurate predictors of contractile reserve, noninvasively induced PESP may be a useful adjunct technique in delineating local contractile reserve in patients with echocardiographic evidence of hypocontractile myocardium of uncertain viability.     

Correlation of vectorcardiogram and electrocardiogram with coronary arteriogram

One hundred patients with suspected coronary heart disease were studied by vectorcardiography (VCG), electrocardiography (ECG), and coronary arteriography. Twenty-eight patients had VCG evidence of anterior infarction; 26 of this group had severe narrowing or obstruction of the left anterior descending branch. Five did not have anterior infarction by ECG. Twenty-seven patients had VCG evidence of diaphragmatic infarction; 25 of this group had severe narrowing of the right coronary artery or the left circumflex branch or both. Six of the 27 did not have ECG evidence of diaphragmatic infarction. Twelve patients had VCG evidence of posterior infarction whereas it was detected by ECG in only two. Only six of the 12, however, had severe narrowing of the nutrient arteries to the posterobasal part of the myocardium. Thirteen patients with infarction had severe narrowing but not total obstruction of a coronary artery. On the other hand, 15 patients had total obstruction of a major coronary vessel without actual infarction.     

Single vessel disease of the anterior interventricular branch as a cause of combined anterior and posterior wall infarct in comparison with 2-vessel disease of the RIVA and RCA

Only few studies deal with the problem of an isolated stenosis of the left anterior descending coronary artery (LAD) leading to a combined anterior and inferior myocardial infarction in the ECG and VCG. In the present study patients with electrocardiographic signs of anterior and inferior myocardial infarction and either one-vessel disease of the LAD branch (n = 27; group I) or two-vessel disease including the LAD and the right coronary artery (RCA) (n = 29; group II) were investigated. Due to the anterior myocardial infarction present in all patients, unequivocal signs of posterior and posterolateral infarct location were missing in the ECG and VCG. There was a distinct variability with regard to Q-wave duration and amplitude in the inferior leads of the ECG and of the Q/R-relation in the scalar lead Y of the VCG (Frank-leads) in patients with isolated LAD disease when compared to those with combined LAD and RCA disease, but no reliable parameter was found in the ECG and VCG which allowed to allocate patients to one of the two groups. On the other hand, there were significant differences in hemodynamics and left ventricular function between the two groups. Group I patients showed a significantly higher left ventricular ejection fraction (mean 49 +/- 15%) than patients with two-vessel disease (group II) (mean 42 +/- 12%) (p less than 0.05). Left ventricular end-diastolic pressures at rest (13 +/- 7 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)     

Reversibility of left ventricular asynergy by nitroglycerin in coronary artery disease

To evaluate the potential reversibility of left ventricular asynergy in patients with coronary artery disease, pre- and postnitroglycerin left ventriculography was performed in 32 subjects. In four other subjects left ventriculography was repeated without intervention of nitroglycerin. Changes in ejection fraction and percentage of systolic shortening of three minor axes from the first to the second angiogram were then calculated. Changes were not significant for the myocardial infarction group or for the control group without the intervention of nitroglycerin. Normal left ventricles showed small but significant changes (p < 0.05). Patients with coronary artery disease but without previous myocardial infarction who demonstrated asynergy in their first angiogram showed three types of response: (1) no significant change (p > 0.05)-irreversible asynergy; (2) significant change (p < 0.025) with residual dysfunction-partially reversible asynergy; (3) significant change (p < 0.001) without residual dysfunction-completely reversible asynergy. It is concluded that postnitroglycerin ventriculography is useful in assessing the reversibility of left ventricular asynergy in patients with coronary artery disease.     

Protective role of collaterals in patients with coronary artery occlusion

We reviewed the clinical, hemodynamic and angiographic data of 105 patients with right coronary artery occlusion and of 82 patients with left anterior descending coronary artery occlusion, subdivided into 3 groups by the presence and quality of collaterals to the occluded coronary (absent, poor or good collaterals). We found that patients with right coronary artery occlusion and good collaterals had a lower frequency of diaphragmatic myocardial infarction (60%) than patients with absent collaterals (100%) (P < 0.01). In addition, in patients with old diaphragmatic myocardial infarction, both poor and good collaterals were associated with a lower frequency of severe asynergy of the diaphragmatic left ventricular segments at left ventriculography (54% and 14%, respectively), compared to patients with no collaterals to the right coronary artery (92%, P < 0.02 vs. poor collaterals, P < 0.001 vs. good collaterals). In contrast, in patients with left anterior descending coronary artery occlusion, the presence of either poor or good collaterals to the left anterior descending coronary artery was not associated with a lower frequency of old anterior myocardial infarction, or, in patients with old anterior myocardial infarction, with a less severe asynergy of the anterior left ventricular segments.Our results suggest that collaterals are effective in protecting the diaphragmatic left ventricular wall in patients with right coronary artery occlusion, but not the anterior left ventricular wall in patients with left anterior descending coronary artery occlusion.     

Reappraisal of the functional significance of the coronary collateral circulation.

A review of data in 465 patients with complete obstruction of either the left anterior descending or right coronary artery was undertaken to evaluate the functional role of the collateral circulation. Complete obstruction of a dominant right coronary artery was observed in 288 patients, 83 percent with distal filling and visualization of the posterior descending artery by way of collateral vessels. Complete obstruction of the left anterior descending artery was noted in 177 patients, 71 percent with filling and visualization distal to the obstruction by way of collateral vessels. Among patients with obstruction of the left anterior descending artery, there was a significantly greater frequency of congestive heart failure and cardiomegaly in those without collateral vessels than in those with collateral vessels. The former also had a significantly greater frequency of both electrocardiographic evidence of an anterior wall myocardial infarction and angiographic findings of anterior wall asynergy. The frequency of inferior myocardial infarction and inferior wall asynergy was not influenced by the presence of collateral vessels. These observations indicate that the collateral circulation plays a significant protective role in the presence of obstruction of the left anterior descending artery, which is not apparent with obstruction of the right coronary artery.     

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.     

Left ventricular hemodynamics and contractile pattern after aortocoronary bypass surgery. Factors affecting reversibility of abnormal left ventricular function

Left ventricular hemodynamics and contractile patterns were evaluated in 104 patients before and after aortocoronary bypass surgery. Patients were selected on the basis of referral for surgery because of angina pectoris and the demonstration, postoperatively, of all grafts being patent. Group I consisted of 47 patients with single grafts (LAD 33 and RCA 14). Mean left ventricular end-diastolic pressure, volume, and ejection fraction revealed no change after surgery. Twenty-four patients had asynergy prior to surgery; of these 24, 16 patients had a normal contractile pattern after surgery. Group II consisted of 47 patients with double vein grafts. Postoperatively, there was a significant decrease in left ventricular end-diastolic pressure (p < 0.005) and increase in ejection fraction (p < 0.001). Asynergy in 29 patients preoperatively revealed synergy after surgery in 15 patients. Group III consisted of ten patients with triple vein grafts. Ejection fraction increased postoperatively (p < 0.01). All but two of the eight patients with asynergy preoperatively showed synergy after surgery. In the entire group of patients, 43 with synergy preoperatively, with but one exception, had synergy after surgery. Asynergesis in 41 instances preoperatively revealed postoperatively that 38 patients (93 per cent) had normal wall movement. In 29 instances of preoperative akinesia of one wall, only 8 patients (28 per cent) showed a return to normal wall movement. Unstable angina pectoris alone did not influence reversibility of abnormal contractile patterns. Unstable angina pectoris with absence of abnormal Q-waves in the ECG was noted in 23 patients with asynergy; all but one of these patients had a normal contractile pattern after surgery. Patients with infarction pattern on the ECG, when accompanied by asynergy, were unlikely to have a normal contractile pattern after surgery (4 out of 23 patients). Reversibility of left ventricular function after surgery is common, not related to number of grafts, but is related to type of wall abnormality noted prior to surgery as well as the ECG and clinical state of the patient.     

Relationship between regional ventricular asynergy and the anatomic lesion in coronary artery disease

The percentage of left ventricular (LV) asynergy was measured in patients with isolated narrowing or obstruction of the right coronary artery (RCA), the anterior descending branch of the left coronary artery (LAD), or a combination of these lesions.Incomplete obstruction of a vessel was not associated with important asynergy. Isolated obstruction of the LAD caused asynergy of the distal two-thirds of the anterior wall and apex of the LV and 46 per cent asynergy. Isolated obstruction of the RCA caused asynergy of the middle or basal thirds of the diaphragmatic surface and 15 per cent asynergy. Double-vessel disease produced a combination of the individual lesions, and total obstruction of both arteries caused extensive asynergy.In each patient the extent of asynergy was modified by the underlying coronary artery anatomy and the collateral circulation. Ejection fraction was related to the percentage of LV asynergy.     

Postinfarction segmental asynergy: correction after angioplasty. Predictive value of exercise thallium scintigraphy]

The aim of this study was twofold: to evaluate the frequency of reversibility of segmental post-subendocardial infarction asynergy after coronary angioplasty, and to test the predictive value of the redistribution phenomenon during stress Thallium scintigraphy with respect to the reversibility of segmental asynergy. The inclusion criteria for this study were: previous postsubendocardial myocardial ischaemia with residual resting or effort ischaemia documented with or without the Thallium test, segmented asynergy documented by quantitative analysis of the ventriculography, complete correction of coronary angioplasty of stenotic single or double vessel disease, a balanced coronary distribution or dominant left coronary in cases of lesion of the circumflex artery. Out of 254 consecutive angioplasty procedures 39 patients met these inclusion criteria. The location of the subendocardial infarct (SEI) was anterior in 17 cases and inferior in 22 cases. The study protocol included a Thallium scintigraphy from the 10th day after SEI, ventriculography 24 hours later, angioplasty and control ventriculography 24 hours after angioplasty. Comparison of the two ventriculographies opposed Group A (reversible asynergy) and Group B (irreversible asynergy) according to criteria defined in 15 normal subjects whose average regional ejection fraction (REF) was 0.53 +/- 0.11. This result enables definition of normal segmental motion if the REF greater than 0.30 (mean--2 SD); hypokinetic if the REF greater than 0.30 or akinetic if the REF less than 0.10 (mean--4 SD). An increase of REF of 0.15 (50% of the minimal normal value) allowed definition of reversibility of asynergy. By these criteria, 19 patients (48.7%) had reversible asynergy after PTCA; 20 had definitive asynergy (51.3%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Anterior ST segment depression during the exercise test in patients with previous inferior myocardial infarct. Scintigraphic and coronary arteriographic correlations

Left ventriculography and coronary arteriography were performed in 49 patients: agreement on location of infarcted area was present between ventriculography and ECG in 22 cases and between ventriculography and myocardial scintigraphy in 34 cases (p less than 0.00125). Consequently on the basis of the scintigraphic redistribution image, all our patients were divided in 2 Groups: Group A, with inferior infraction (120 cases), and Group B, with infero-posterior or posterior infarction (68 cases). Exercise test showed anterior ST segment depression in 97 patients (59 from Group A and 38 from Group B). In these cases myocardial scintigraphy showed anterior ischemia in 48 (81%) patients of Group A and only in 17 (45%) of Group B (p less than 0.005). In patients with negative exercise test, myocardial scintigraphy detected anterior ischemia with similar incidence in both groups (about 40%). Out of the 49 patients studied by coronary arteriography, 33 had left anterior descending coronary artery disease: exercise test induced anterior ST depression in 25 of them (sensitivity 77%), while myocardial scintigraphy showed anterior ischemia in 29 (sensitivity 87%). Normal coronary arteries or isolated right or circumflex artery disease were found in 16 patients: 9 of them had anterior ST depression (specificity 56%) and none showed scintigraphic evidence of anterior ischemia (specificity 100%). In conclusion, in patients with previous infarction of inferior and/or posterior wall, ST-segment depression induced by exercise in anterior leads can be a false positive result, without a corresponding anterior myocardial ischemia. This finding is more often observed in patients with infarction of the posterior wall, in whom anterior ST depression on exercise might be due to ischemia or dyssynergy of the infarcted area. Myocardial scintigraphy allows a more precise identification of the scar location, and above all it is provided with good sensitivity and specificity in identifying residual ischemia due to left anterior descending coronary disease.     

Comparison of two-dimensional echocardiography and Tl-201 SPECT in the evaluation of ischemic heart disease

To ascertain the influence of severity of coronary stenosis and the presence or absence of collateral circulations on echocardiographic (2DE) asynergy or abnormal myocardial perfusion by exercise Tl-201 SPECT, we performed a correlative study of 40 patients undergoing coronary angiography, including 27 with myocardial infarction and 13 with angina pectoris, whose mean age was 55 years. Each view of the left ventricle (LV) obtained by both methods was assigned to five segments; i.e., anterior, septal, inferior, lateral and apical. The correlation of abnormal segments was investigated using both methods. The segments showing a severe perfusion defect coincided those with severe asynergy. Among 116 segments with normal perfusion, 99 (85%) revealed normal wall motion, but the remaining 15% showed asynergy. Among 84 segments with abnormal myocardial perfusion, 26 (31%) had normal wall motion, and most of these were non-infarcted regions. Concerning the severity of coronary artery stenosis, greater than 99% coronary arterial stenoses existed in most of the segments showing a complete defect or incomplete redistribution on Tl-201 SPECT and akinesis or hypokinesis on 2DE. Collaterals were observed in 22% of the segments with a complete defect and 66% of segments with incomplete redistribution; whereas, there was no significant correlation between the severity of LV wall motion abnormality and the presence or absence of collaterals. The severity of asynergy is possibly related to the severity of abnormal myocardial perfusion, however, asynergy could occur at the site of ischemic regions where Tl-201 SPECT can not detect the abnormalities. In patients with myocardial infarction who show incomplete redistribution by exercise Tl-201 SPECT, temporal ischemia of collaterals might cause such a perfusion abnormality.