Increased serum concentrations of interleukin-1 beta in patients with coronary artery disease

OBJECTIVE

To assess serum interleukin-1 beta (IL-1 beta) concentrations in patients with ischaemic heart disease, to characterise subgroups of patients with raised IL-1 beta concentrations, and to examine whether serum IL-1 beta concentrations correlate with non-specific indices of inflammation.

DESIGN

Survey study of patients with ischaemic heart disease.

SETTING

Cardiac catheterisation laboratory of a tertiary medical centre.

PATIENTS

Consecutive patients with angina pectoris and patients recovering from uncomplicated acute myocardial infarction and undergoing elective coronary angiography.

RESULTS

Mean(SD) serum IL-1 beta concentrations were higher (P < 0.001) in patients with angina and < 50% coronary artery stenosis (n = 11; 18.8(19.9) pg/ml), patients with angina > or = 50% stenosis (n = 23; 10.2(11.4) pg/ml), and patients 8(0.8) days post-infarction (n = 13; 4.4(5.8) pg/ml) than in 15 healthy, age-matched controls (0.3(0.5) pg/ml). Serum IL-1 beta concentrations did not correlate with total blood leucocyte counts (r = -0.07, P = NS), blood lymphocyte counts (r = -0.24, P = NS), and blood monocyte counts (r = -0.29, P = NS), or with fibrinogen (r = -0.16, P = NS) and C-reactive protein concentrations (9(10.5) mg/dl v 14.1(19) mg/dl for patients with undetectable and detectable concentrations, respectively, P = NS).

CONCLUSION

Serum IL-1 beta concentrations are raised in patients with ischaemic heart disease, in particular in those with minimal coronary artery disease and angina. The precise role of IL-1 beta in coronary artery disease remains to be determined.

Prognostic significance of the admission electrocardiogram in acute myocardial infarction

OBJECTIONS

We sought to access the ST segment and the terminal portion of the QRS complex in the initial electrocardiogram (ECG) as tools to predict outcome in patients with acute myocardial infarction given thrombolytic therapy.

BACKGROUND

Previous studies assessing early risk stratification of patients with acute myocardial infarction by ECG criteria have focused on the number of leads with ST segment elevation or the absolute magnitude of ST deviation. A new classification independent of the absolute values of ST deviation was pursued.

METHODS

Patients with ST elevation and positive T waves in at least two adjacent leads who received thrombolytic therapy were classified into two groups based on the absence (1,232 patients) or presence (1,371 patients) of distortion of the terminal portion of the QRS complex on the admission ECG.

RESULTS

There were no differences between groups in the prevalence of previous angina, hypertension, current smoking, anterior infarction, time from onset of symptoms to therapy of type of thrombolytic regimen. Patients with QRS distortion were less likely to have had a previous infarction (12.0% vs. 18.4%, p = 0.02) or diabetes mellitus (16.9% vs. 21.4%, p = 0.003). They had higher peak creatine kinase levels (1,617 +/- 1,670 vs. 1,080 +/- 1,343 IU, p = 0.00001). Hospital mortality for those with and without QRS distortion was 6.8% and 3.8%, respectively (p = 0.0008). Multivariable logistic regression analysis confirmed that hospital mortality was independently associated with distortion of terminal portion of the QRS complex (odds ratio 1.78, 95% confidence interval 1.19 to 2.68, p = 0.004).

CONCLUSIONS

Distortion of the terminal portion of the QRS complex on the admission ECG is independently associated with a higher hospital mortality rate in patients with acute myocardial infarction given thrombolytic therapy.

Predicting postinfarction left ventricular dysfunction based on the configuration of the QRS complex and ST segment in the initial ECG of patients with a first anterior wall myocardial infarction

The objective of the study was to identify patients with anterior wall acute myocardial infarction (AMI) at high risk of postinfarction left ventricular dysfunction (LVD). This study population included all patients admitted with a diagnosis of anterior wall AMI (ST segment elevation of > 1 mm in 2 or more precordial leads) without history or ECG evidence of antecedent AMI,who underwent assessment of left ventricular ejection fraction (LVEF) during emergency hospitalization. ST segment deviation from baseline was measured manually 0.08 s after the J point in all leads. Patients (n = 81) were classified into two groups based on the configuration of the QRS complex and ST segment: ST > 1 mm with preserved (pattern A; n = 60) or distorted terminal QRS (emergence of the J point at a level above the lower half of the R wave or disappearance of the S wave in leads with an Rs configuration; pattern B; n = 21). LVD (LVEF < 40%) was significantly more prevalent in patients with pattern B than pattern A (48 vs. 12%; p = 0.002). There was no correlation between the number of leads with ST segment elevation and LVD (p = 0.47). The sum of ST segment elevation in involved leads correlated weakly, yet significantly with LVEF (R = -0.22; p < 0.05). In conclusion, patients with anterior wall AMI and pattern B in the initial ECG are at high risk of post-AMILVD.

Increased adhesiveness of peripheral blood leukocytes corresponds to the appearance of expansion following anterior wall myocardial infarction

The appearance of increased leukocyte adhesiveness/aggregation as an inflammatory marker in the peripheral blood of patients with anterior wall myocardial infarction was monitored. Of the 26 patients included in the study, 7 had infarct expansion as shown by an enlargement of left ventricular end-diastolic volume. The percent of aggregated leukocytes in the peripheral blood of patients with expansion (29.7 +/- 15.5%) was significantly higher (p = 0.01) than that obtained from patients with no expansion (18.5 +/- 6.8%). The lack of significant differences in peak creatine kinase concentrations between patients with and without expansion suggests that infarct size is not necessarily the main determinant for the appearance of expansion; an increased inflammatory reaction could be a contributory factor.

Acute myocardial infarction entailing ST-segment elevation in lead aVL: electrocardiographic differentiation among occlusion of the left anterior descending, first diagonal, and first obtuse marginal coronary arteries

Acute myocardial infarction with ST elevation in lead aVL may represent involvement of the first diagonal or the first obtuse marginal branch. This study assesses the correlation among different electrocardiographic patterns of acute myocardial infarction with ST elevation in aVL and the site of the infarct-related artery occlusion. Patients who underwent coronary angiography within 14 days of infarction with an unequivocal culprit lesion were included. Fifty-seven patients were evaluated. The culprit lesion was in the left anterior descending coronary artery proximal to the first diagonal, first diagonal, and first obtuse marginal branches, in 38, 8, and 11 patients, respectively. ST elevation in aVL and V2 through V5 signifies left anterior descending artery occlusion proximal to the first diagonal branch (positive predictive value [PPV] and negative predictive value [NPV] of 95% and 94%, respectively). ST elevation in aVL and V2, not accompanied by ST elevation in V3 through V5, favors occlusion of the first diagonal branch (PPV, 89%; NPV, 100%). ST elevation in aVL accompanied by ST depression in V2 predicts obstruction of the first obtuse marginal branch (PPV, 100%; NPV, 98%).

Prognostic significance of the initial electrocardiographic pattern in patients with inferior wall acute myocardial infarction

The purpose of the study was to determine whether the initial electrocardiographic pattern is predictive of in-hospital mortality in inferior wall acute myocardial infarction. It is commonly perceived that patients with acute myocardial infarction presenting with greater ST elevation have a worse prognosis. The initial electrocardiogram of patients (n = 213) with inferior wall myocardial infarction was categorized based on the pattern of ST-segment elevation in inferior leads: (A) ST <1 mm with tall T waves, (B) ST > or = 1 mm with normal terminal QRS, and (C) ST > or = 1 mm with distortion of terminal QRS. ST deviation from baseline was calculated for all leads. Patients with maximal precordial ST depression in V4-V6 and pattern A had an in-hospital mortality rate of 68.8% compared with 16.9% for the entire study group. By univariate analysis, only pattern A was significantly predictive of in-hospital mortality [odds ratio = 2.91, 95% confidence interval (CI) 1.22-6.93], but by multivariate analysis adjusted for (1) age, (2) diabetes mellitus, (3) previous myocardial infarction, (4) thrombolytic therapy, (5) precordial ST-depression pattern, and (6) patterns of ST elevation, maximal ST depression in V4-V6 was significantly predictive (odds ratio = 4.93, 95% CI 1.79-13.56), whereas pattern A was not (odds ratio = 1.12, 95% CI 0.36-3.52). Contrary to popular perception, patients with inferior wall myocardial infarction presenting with minimal ST-segment elevation are at highest risk for in-hospital mortality, especially if accompanied by maximal precordial ST depression in V4-V6.

The predictive value of the electrocardiographic pattern of acute Q-wave myocardial infarction for recurrent ischemia

A total of 140 consecutive patients with acute Q-wave myocardial infarction was evaluated to assess the relationship between different electrocardiographic patterns of evolution and the incidence of recurrent ischemia within 10 days of infarction. Patients were allocated to three groups according to the electrocardiogram at 12 h after admission: Group A: ST elevation of < 2 mm and negative T waves (75 patients); Group B: ST elevation of > 2 mm and negative T waves (35 patients); Group C: ST elevation of > 2 mm and positive T waves (30 patients). Patients in Group C had more anterior wall infarctions (82%) than Group A (40%) or Group B (58%) (p = 0.0001). Peak creatine kinase levels were lower in Group A (782 +/- 115 IU) than in Groups B (1415 +/- 257 IU) and C (1501 +/- 287 IU) (p < 0.0001). The occurrence of post-infarction recurrent ischemia was more frequent in Group A (79.2%) than in Groups B (33.3%) and C (14.8%) (p < 0.0001). Patients in Group A had relatively smaller infarctions and a higher incidence of recurrent ischemia, whereas patients in Group C had larger infarctions and a lower incidence of recurrent ischemia. The electrocardiographic pattern 12 h after admission for acute myocardial infarction is helpful in identifying a subgroup at high risk of recurrent ischemia.

QT prolongation and polymorphous ventricular tachycardia associated with trasodone-amiodarone combination

Trasodone, a second generation antidepressant, has been shown to equal standard tricyclics in clinical efficacy while causing significantly fewer cardiac side effects. Although clinical trials have demonstrated a relatively safe arrhythmogenic profile, trasodone has been implicated in the pathogenesis of ventricular arrhythmias. This report describes a patient in whom the administration of trasodone in addition to previously well-tolerated long-term amiodarone therapy was associated with a marked prolongation of the QT interval and polymorphous ventricular tachycardia. Caution in the concurrent use of trasodone and other medications known to cause QT prolongation and polymorphous ventricular tachycardia is recommended.

Inferior wall acute myocardial infarction with one-lead ST-segment elevation: electrocardiographic distinction between a benign and a malignant clinical course

BACKGROUND

In most clinical trials, ST-segment elevation in two contiguous leads is required for diagnosis of acute myocardial infarction (AMI). This study describes the clinical course of patients with inferior wall AMI with one-lead ST-segment elevation in lead L3 in the initial ECG.

METHODS

Of 394 consecutive patients with inferior wall AMI, 31 (7.8%) had an initial ECG showing ST-segment elevation (+/- 1 mm) only in lead L3 (ST < 1 mm in leads L2 and aVF) and upright T waves in inferior leads. Patients were categorized into three groups: (I) no precordial ST-segment depression (n = 6), (II) maximal precordial ST-segment depression in leads V1-V3 (n = 4), and (III) maximal precordial ST-segment depression in leads V4-V6 (n = 21).

RESULTS

Patients in group III developed severe heart failure (pulmonary edema or cardiogenic shock) six times more frequently than those in groups I-II (62 versus 10%). Among patients who underwent coronary angiography, three-vessel coronary artery disease (> 50% stenosis) was more common in group III. Five of six patients in group III who underwent emergency angioplasty of the right coronary artery because of cardiogenic shock survived.

CONCLUSION

Patients with inferior wall AMI and an initial ECG with ST-segment elevation only in lead L3, and maximal precordial ST-segment depression in leads V4-V6, are at risk of severe complications, especially heart failure, but their clinical course may be ameliorated by employing an aggressive interventional strategy.

ST segment depression in lateral limb leads in inferior wall acute myocardial infarction. Implications regarding the culprit artery and the site of obstruction

We examined whether the pattern of ST segment depression in lateral leads (I, aVL, V5, V6) in the initial electrocardiogram of patients (n = 88) with inferior wall acute myocardial infarction (ST segment elevation of > or = mm in > or = 2 inferior leads) correlates with the site of obstruction, as determined angiographically during acute hospitalization. Of the 62 patients in which the culprit artery could be determined unequivocally, in 46 the culprit artery was the right coronary artery (20 proximal to the first right ventricular branch and 26 distal), and in 16 the left circumflex coronary artery (seven proximal to the first marginal branch or involving a high first marginal branch, and nine with distal obstruction). Significant ST segment depression (ST < or = 1 mm) in leads I and aVL was more common in right coronary artery obstruction (P < 0.05 and P < 0.0001, respectively). The absence of significant ST segment depression in lead aVL was most common in proximal circumflex obstruction (P < 0.0001), with a similar trend for lead I (P < 0.11). ST segment depression patterns in leads V5 and V6 were not indicative of the infarct-related artery or the site of obstruction. Thus, significant ST segment depression in leads I and aVL indicates right coronary artery-associated inferior wall acute myocardial infarction with a sensitivity of 70% and 100%, and a specificity of 63% and 38%, respectively, whereas the lack of ST segment depression in these leads indicates proximal circumflex obstruction with a sensitivity of 71% and 86%, and a specificity of 65% and 100%, respectively.

ST segment reelevation after acute myocardial infarction: marked differences in the electrocardiographic pattern between early and late episodes

This study assesses the electrocardiographic (ECG) morphologic differences between early (< 24 h) and late (> 24 h) episodes of ST segment reelevation after acute myocardial infarction. We studied the records of 101 consecutive patients with acute myocardial infarction whose admission ECG demonstrated ST segment elevation with positive T waves, without pathological Q waves in the relevant leads, and without signs of bundle branch block or left ventricular hypertrophy. Thirty-five patients had 44 episodes of early ST segment reelevation, while 22 patients experienced 26 late episodes of ST segment reelevation. Seven patients experienced both early and late episodes. Early episodes of ST segment reelevation was seen more often after thrombolytic therapy: 43% (32 of 74 patients) versus 11% (3 of 27 patients) (P < 0.006). No differences were found in the incidence of late episodes between those who underwent (23%) or did not undergo (19%) thrombolytic therapy. Two patterns of ST segment elevation were distinguished. Pattern A with positive T waves, ST segment elevation (> or = 0.1 mV), but without distortion of the terminal portion of the QRS complex. Pattern B characterized by positive T waves, ST segment elevation (> or = 0.1 mV) with distortion of the terminal portion of the QRS complex. Each ECG was categorized according to these two patterns. The admission ECG pattern was A in 75 patients, and B in 26. No significant differences were found between patients with early, late, or no episodes of ST segment reelevation in the appearance of pattern A or B on admission.(ABSTRACT TRUNCATED AT 250 WORDS)

T lymphocyte activation in stable angina pectoris and after percutaneous transluminal coronary angioplasty

BACKGROUND

Inflammatory reactions have an important part in atherosclerosis. Smooth muscle cells, endothelial cells, monocytes, and T lymphocytes are actively involved. The purpose of this study was to assess whether T lymphocytes are activated in patients with stable angina pectoris who are candidates for a percutaneous transluminal coronary angioplasty (PTCA) and the influence of PTCA on this process.

METHODS AND RESULTS

Twenty-four patients participated in the study. All were 40- to 60-year-old men, and all but one underwent successful PTCA. Blood samples were taken 1 day before PTCA and 1 week, 1 month, and 2 months after. Two groups of patients were detected: group A, 11 patients who had high levels of soluble interleukin-2 receptor (sIL-2R) before PTCA that decreased toward normal during the follow-up period in most of them; and group B, 13 patients who did not have elevated sIL-2R levels before PTCA and in whom sIL-2R levels did not change after the procedure. Group C consisted of 15 healthy men whose sIL-2R levels were in the normal range (control subjects).

CONCLUSIONS

(1) T lymphocytes are activated in stable angina patients. (2) The level of sIL-2R can be a reliable laboratory marker for follow-up of patients after PTCA, especially those with high sIL-2R levels before the procedure.

Clinical significance and predisposing factors to symptomatic bradycardia and hypotension after percutaneous transluminal coronary angioplasty

Of 180 consecutive patients who underwent uneventful percutaneous transluminal coronary angioplasty (PTCA), 25 (13.9%) had at least 1 episode of symptomatic bradycardia and hypotension during the early postprocedure period. Symptomatic bradycardia and hypotension occurred 1 to 10 hours (mean 4 +/- 2) after PTCA. A higher incidence of symptomatic bradycardia and hypotension was found in patients receiving regular treatment with beta blockers (26% vs 10% in patients without beta blockers in their regimen, p < 0.01), diltiazem or verapamil (20% vs 9%, p < 0.025), or both a beta blocker and diltiazem or verapamil (64% vs 11%, p < 0.001). A higher incidence was also associated with angioplasty of the left anterior descending coronary artery compared with angioplasty of the other coronary arteries (22% vs 8%, p < 0.01). It is concluded that symptomatic bradycardia and hypotension is a common occurrence after PTCA. The incidence is higher after PTCA to the left anterior descending coronary artery and in patients receiving diltiazem, verapamil, and beta-blocking agents; it is particularly high in patients receiving a combination of a beta-blocking agent and either diltiazem or verapamil.

Prognostic significance of maximal precordial ST-segment depression in right (V1 to V3) versus left (V4 to V6) leads in patients with inferior wall acute myocardial infarction

This study examines whether patients with inferior wall acute myocardial infarction (AMI) and maximal ST-segment depression in left precordial leads are at higher risk for in-hospital mortality. The charts of patients (n = 213) with inferior wall AMI and an initial electrocardiogram that displayed peaked, tall T waves or ST-segment elevation with upright T waves in inferior leads were reviewed, after excluding patients with inverted T waves in inferior leads (n = 75). ST-segment deviation from baseline was measured for all leads. Patients were classified into 3 types: I = no precordial ST-segment depression; II = sum of ST-segment depression in leads V1 to V3 equal to or more than the sum of ST-segment depression in leads V4 to V6; and III = maximal precordial ST-segment depression in leads V4 to V6. Thirty-six patients (17%) died in the hospital. In-hospital mortality rates for patients with types I and II were 12% and 10%, respectively, compared with 41% for those with type III (p < 0.0001). Mortality rates in surviving patients were similar for all types up to 1 year after infarction. Multivariate logistic regression models for in-hospital mortality by ST-segment depression type adjusted for age, previous AMI, diabetes mellitus, and thrombolytic therapy revealed that type III pattern was a strong predictive factor for in-hospital mortality (odds ratio = 4.9, p = 0.0008, 95% confidence interval 1.93 to 12.26). Thus, patients with inferior wall AMI and maximal precordial ST-segment depression in leads V4 to V6 are at high risk for in-hospital mortality.

Isolated mid-anterior myocardial infarction: a special electrocardiographic sub-type of acute myocardial infarction consisting of ST-elevation in non-consecutive leads and two different morphologic types of ST-depression

We describe eight patients with a distinct electrocardiographic pattern of anterior wall myocardial infarction characterized by three main features: (1) a pattern of 'transmural ischemia' (ST-elevation with positive T-wave) in non-consecutive leads: a VL and V2, and two different types of ST-depression; (2) a pattern of 'true reciprocal changes' (ST-depression and negative T-wave) in III and a VF; (3) a pattern of 'sub-endocardial ischemia' (ST-depression with positive T-wave) in V4-5, while ST in V3 was either isoelectric or depressed. We characterize the electrocardiographic features and correlate them with the echocardiographic, radionuclide, and angiographic data. All patients admitted to the coronary care unit from January 1990 to April 1992 with evolving acute myocardial infarction were evaluated prospectively. Patients whose admission electrocardiogram met the description above were included. The electrocardiographic evolution, echocardiographic, Technetium MIBI tomography, and coronary angiography are described. Of 471 patients with acute anterior wall myocardial infarction, admitted to the coronary care unit during the study period, eight patients met the inclusion criteria (1.7% of acute anterior wall myocardial infarction). Echocardiographic studies revealed mid-anterior hypokinesis in two patients, anterior and apical hypokinesis in one, and no wall motion abnormality in four patients. Technetium MIBI tomography, done in five patients, was consistent with mid-anterior or midanterolateral infarction without involvement of the septum or apex. Coronary angiography, performed in seven patients, demonstrated significant obstruction of the first diagonal branch in all of the patients. In four patients, the diagonal occlusion was the only significant coronary lesion in the left coronary artery.

CONCLUSION

Most of the anterior myocardial infarctions also involve the septal and apical regions. Anterior wall myocardial infarctions limited to the mid-anterior or mid-anterolateral wall, without apical or septal wall involvement are relatively rare. This study describes a special electrocardiographic form of anterior wall acute myocardial infarction. This distinct electrocardiographic pattern represents true mid-anterior wall myocardial infarction, caused by occlusion of a first diagonal branch of the left anterior descending coronary artery. The septal and apical regions are not involved because the blood supply via the left anterior descending artery is not interrupted.

Implications of inferior ST-segment depression in anterior acute myocardial infarction: electrocardiographic and angiographic correlation

This study assesses the significance of inferior ST-segment depression during anterior acute myocardial infarction (AMI) by investigating the relationship between inferior ST-segment depression and (1) the site of the left anterior descending (LAD) coronary artery lesion and (2) ST-segment deviation in the various anterior and lateral leads. We studied 126 patients with anterior AMI who underwent coronary angiography within 21 days of hospitalization. The admission 12-lead electrocardiograms were evaluated for ST-segment amplitude in each lead at 0.08 second after the J-point. Coronary angiography was evaluated for the site and severity of luminal narrowing of the coronary arteries. The site of the culprit lesion in the LAD artery, relative to the origin of the first septal and diagonal branches, was determined. In four patients no lesion was identified in the LAD artery. Of the remaining 122 patients, 40 and 53 patients had a LAD artery lesion proximal to the first septal and first diagonal branches, respectively. Additional luminal narrowing (> or = 70% of diameter) was found in the circumflex and the right coronary arteries in 27 and 37 patients, respectively. ST-segment depression of > 1 mm in leads II, III, and aVF was noted in 24, 29, and 24 patients, respectively. The prevalence of a LAD artery preseptal and prediagonal lesion was higher in patients with inferior ST-segment depression.(ABSTRACT TRUNCATED AT 250 WORDS)

Levels of T-lymphocyte subpopulations, interleukin-1 beta, and soluble interleukin-2 receptor in acute myocardial infarction

T-lymphocyte levels may adversely affect the clinical course and outcome of patients with acute myocardial infarction (AMI). To characterize the T-lymphocyte profile during AMI and to explore whether these cells play a detrimental role in the extent of myocardial insult, levels of T-lymphocyte subpopulations, free soluble interleukin-2 receptor (sIL-2R), and interleukin-1 beta (IL-1 beta), were measured during the first week of AMI. Results were correlated with left ventricular ejection fraction (LVEF), age, sex, survival rate, thrombolytic therapy, and the occurrence of reinfarction. Thirty-nine patients, 20 men and 19 women aged 30 to 80 years, with first AMI were included. Patients were divided into two groups. Group A (13 patients) experienced reinfarction; group B (26 patients) did not. T-helper and-suppressor cells were measured by the indirect immunofluorescence method and sIL-2R and IL-1 serum levels by enzyme-linked immunosorbent assay (ELISA) methods on days 1, 4, and 7 after AMI. A low count of T-helper cells (CD4) was found on the first day after AMI in both AMI groups; however, the count returned to normal in group B but not in group A. A significant correlation (r = 0.63) was found between T-helper cell count on day 4 of AMI and LVEF assessed by radionuclide ventriculography, and between the CD4/CD8 ratio on day 1 and the creatine phosphokinase level (r = -0.6950). High sIL-2R levels were found in groups A and B of the AMI patients as compared with the control group (p < or = 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Bundle-branch reentry tachycardia

A 21-year-old man with aborted sudden death developed bundle-branch reentry tachycardia at electrophysiologic study. Ablation of the right bundle branch was performed in an attempt to eliminate the recurrence of ventricular arrhythmia. The clinical arrhythmia was no longer inducible; however, a second type of ventricular tachycardia of a different mechanism and origin was induced. Following a new clinical episode of ventricular tachycardia with hemodynamic deterioration, an automatic implantable cardioverter and defibrillator was implanted.

Prediction of arrhythmic events after acute myocardial infarction using two methods for late potentials recording

One hundred consecutive patients recovering from an acute myocardial infarction underwent, prior to home discharge, signal-averaged electrocardiography (ECG), left ventriculography, and 24-hour Holter ECG recording. The signal-averaged ECG was recorded and analyzed using two procedures: the orthogonal bipolar XYZ lead configuration with a bidirectional filter; and a precordial unipolar lead configuration with a nonrecursive digital filter. An abnormal signal-averaged ECG was seen in 40% of patients with the XYZ system and in 30% of patients in the precordial method, abnormal ejection fraction (< 40%) in 24% of patients and high grade ectopy activity in 22%. During the 24-month follow-up period, 12 patients (12%) had an arrhythmic event defined as either sudden death (11 patients) or sustained ventricular tachycardia (1 patient). Neither the signal-averaged ECG with the XYZ configuration, the abnormal ejection fraction, nor the high grade ectopy were able to statistically predict a higher arrhythmic event rate. The signal-averaged ECG with the precordial configuration was able to statistically predict a higher arrhythmic event rate, P < 0.03; odds ratio = 3.96. The combination of the orthogonal XYZ configuration signal-averaged ECG with the ejection fraction (P < 0.01, odds ratio = 7.33), or with ejection fraction and Holter monitoring (P < 0.06, odds ratio = 6.17) was able to predict a higher arrhythmic event rate. The combination of the precordial configuration signal-averaged ECG with the ejection fraction (P < 0.002, odds ratio = 14.4), or with ejection fraction and Holter monitoring (P < 0.06, odds ratio = 10) was able to better predict a higher arrhythmic event rate.(ABSTRACT TRUNCATED AT 250 WORDS)