The prognostic significance of the electrical QRS axis on long-term mortality in acute coronary syndrome patients - The TACOS study.

INTRODUCTION: There are several potential causes of QRS-axis deviation in the ECG, but there is limited data on the prognostic significance of QRS-axis deviation in ACS patients. SUBJECTS AND METHODS: We evaluated the long-term prognostic significance of acute phase frontal plane QRS-axis deviation and its shift during hospital stay in ACS patients. A total of 1026 patients who met the inclusion criteria were divided into three categories: normal (n = 823), left (n = 166) and right/extreme axis (n = 37). RESULTS: The median survival time was 9.0 years (95% CI 7.9-10.0) in the normal, 3.6 years (95% CI 2.4-4.7) in the left and 1.3 years (95% CI 0.2-2.4) in the right/extreme axis category. Both short and long-term all-cause mortality was lowest in the normal axis category and highest in the right/extreme axis category. Compared to normal axis, both admission phase QRS-axis deviation groups were independently associated with a higher risk of all-cause mortality. When including left ventricular hypertrophy in the ECG, only the right/extreme axis retained its statistical significance (aHR 1.76; 95% CI 1.16-2.66, p = 0.007). Axis shift to another axis category had no effect on mortality. CONCLUSION: In ACS patients, acute phase QRS-axis deviation was associated with higher risk of all-cause mortality. Among the axis deviation groups, right/extreme QRS-axis deviation was the strongest predictor of mortality in the multivariable analysis. Further studies are required to investigate to what extent this association is caused by pre-existing or by ACS-induced axis deviations. QRS-axis shift during hospital stay had no effect on all-cause mortality.

The Effect of Atrial Fibrillation on the Long-Term Mortality of Patients with Acute Coronary Syndrome: The TACOS Study.

INTRODUCTION: Atrial fibrillation (AF) is a frequent finding in acute coronary syndrome (ACS), but there is conflicting scientific evidence regarding its long-term impact on patient outcome. The aim of this study was to survey and compare the ≥10-year mortality of ACS patients with sinus rhythm (SR) and AF. METHODS: Patients were divided into 2 groups based on rhythm in their 12-lead ECGs: (1) SR (n = 788) at hospital admission and discharge (including sinus bradycardia, physiological sinus arrhythmia, and sinus tachycardia) and (2) AF/atrial flutter (n = 245) at both hospital admission and discharge, or SR and AF combination. Patients who failed to match the inclusion criteria were excluded from the final analysis. The main outcome surveyed was long-term all-cause mortality between AF and SR groups during the whole follow-up time. RESULTS: Consecutive ACS patients (n = 1,188, median age 73 years, male/female 58/42%) were included and followed up for ≥10 years. AF patients were older (median age 77 vs. 71 years, p < 0.001) and more often female than SR patients. AF patients more often presented with non-ST-elevation myocardial infarction (69.8 vs. 50.4%, p < 0.001), had a higher rate of diabetes (31.0 vs. 22.8%, p = 0.009), and were more often using warfarin (32.2 vs. 5.1%, p < 0.001) or diuretic medication (55.1 vs. 25.8%, p < 0.001) on admission than patients with SR. The use of warfarin at discharge was also more frequent in the AF group (55.5 vs. 14.8%, p < 0.001). The rates of all-cause and cardiovascular mortality were higher in the AF group (80.9 vs. 50.3%, p < 0.001, and 73.8 vs. 69.6%, p = 0.285, respectively). In multivariable analysis, AF was independently associated with higher mortality when compared to SR (adjusted HR 1.662; 95% CI: 1.387-1.992, p < 0.001). CONCLUSION: AF/atrial flutter at admission and/or discharge independently predicted poorer long-term outcome in ACS patients, with 66% higher mortality within the ≥10-year follow-up time when compared to patients with SR.

Poor long-term outcome in acute coronary syndrome in a real-life setting: Ten-year outcome of the TACOS study.

BACKGROUND: Long-term outcome of the three categories of acute coronary syndrome (ACS) in real-life patient cohorts is not well known. The objective of this study was to survey the 10-year outcome of an ACS patient cohort admitted to a university hospital and to explore factors affecting the outcome. METHODS: A total of 1188 consecutive patients (median age 73 years) with ST-elevation myocardial infarction (STEMI), non-ST-elevation myocardial infarction (NSTEMI) or unstable angina pectoris (UA) in 2002-2003 were included and followed up for ≥ 10 years. RESULTS: Mortality for STEMI, NSTEMI and UA patients during the follow-up period was 52.5%, 69.9% and 41.0% (p < 0.001), respectively. In multivariable Cox regression analysis, only age and creatinine level at admission were independently associated with patient outcome in all the three ACS categories when analyzed separately. CONCLUSIONS: All the three ACS categories proved to have high mortality rates during long-term followup in a real-life patient cohort. NSTEMI patients had worse outcome than STEMI and UA patients during the whole follow-up period. Our study results indicate clear differences in the prognostic significance of various demographic and therapeutic parameters within the three ACS categories.

Long-term outcome of pre-specified ECG patterns in acute coronary syndrome.

BACKGROUND: Long-term outcome of real-life acute coronary syndrome (ACS) patients with selected ECG patterns is not well known. PURPOSE: To survey the 10-year outcome of pre-specified ECG patterns in ACS patients admitted to a university hospital. METHODS: A total of 1184 consecutive acute coronary syndrome patients in 2002-2003 were included and followed up for 10 years. The patients were classified into nine pre-specified ECG categories: 1) ST elevation; 2) pathological Q waves without ST elevation; 3) left bundle branch block (LBBB); 4) right bundle branch block (RBBB) 5) left ventricular hypertrophy (LVH) without ST elevation except in leads aVR and/or V1; 6) global ischemia ECG (ST depression ≥0.5 mm in 6 leads, maximally in leads V4-5 with inverted T waves and ST elevation ≥0.5 mm in lead aVR); 7) other ST depression and/or T wave inversion; 8) other findings and 9) normal ECG. RESULTS: Any abnormality in the ECG, especially Q waves, LBBB, LVH and global ischemia, had negative effect on outcome. In age- and gender adjusted Cox regression analysis, pathological Q waves (HR 2.28, 95%CI 1.20-4.32, p = .012), LBBB (HR 3.25, 95%CI 1.65-6.40, p = .001), LVH (HR 2.53, 95%CI 1.29-4.97, p = .007), global ischemia (HR 2.22, 95%CI 1.14-4.31, p = .019) and the combined group of other findings (HR 3.01, 95%CI 1.56-6.09, p = .001) were independently associated with worse outcome. CONCLUSIONS: During long-term follow-up of ACS patients, LBBB, ECG-LVH, global ischemia, and Q waves were associated with worse outcome than a normal ECG, RBBB, ST elevation or ST depression with or without associated T-wave inversion. LBBB was associated with the highest mortality rates.

The prognostic significance of a positive or isoelectric T wave in lead aVR in patients with acute coronary syndrome and ischemic ECG changes in the presenting ECG - Long-term follow-up data of the TACOS study.

BACKGROUND: A positive T wave in lead aVR (aVRT+) is an independent prognostic predictor of cardiovascular mortality in the general population as well as in cardiovascular disease. SUBJECTS AND METHODS: We evaluated the prognostic impact of aVRT+ in an ECG recorded as close to hospital discharge as possible in acute coronary syndrome patients (n = 527). We divided the patients into three categories based on the findings in the admission ECG: ST elevation, global ischemia and other ST/T changes. RESULTS: In the whole study population, and in all the three ECG subgroups, the 10-year all-cause mortality rate was higher in the aVRT+ group than in the aVRT- group. In Cox regression analysis, the age and gender adjusted hazard ratio (HR) for aVRT+ to predict all-cause mortality in the whole study population was 1.43 (95% confidence interval [CI] 1.12-1.83; p = 0.004). To predict cardiovascular mortality, the age and gender adjusted HR for aVRT+ was 1.54 (95% CI 1.14-2.07; p = 0.005) in the whole study population and 2.07 (95% CI 1.07-4.03; p = 0.032) in the category with other ST/T changes. CONCLUSION: In ACS patients with or without ST elevation, but with ischemic ST/T changes in their presenting ECG, a positive or isoelectric T wave in lead aVR in an ECG recorded in the subacute in-hospital stage is associated with all-cause and cardiovascular mortality during long-term follow-up. Clinicians should pay attention to this simple ECG finding at hospital discharge.

The high-risk ECG pattern of ST-elevation myocardial infarction: A substudy of the randomized trial of primary PCI with or without routine manual thrombectomy (TOTAL trial).

BACKGROUND: Useful tools for risk assessment in patients with STEMI are needed. We evaluated the prognostic impact of the evolving myocardial infarction (EMI) and the preinfarction syndrome (PIS) ECG patterns and determined their correlation with angiographic findings and treatment strategy. METHODS: This substudy of the randomized Trial of Routine Aspiration Thrombectomy with PCI versus PCI Alone in Patients with STEMI (TOTAL) included 7860 patients with STEMI and either the EMI or the PIS ECG pattern. The primary outcome was a composite of death from cardiovascular causes, recurrent MI, cardiogenic shock, or New York Heart Association (NYHA) class IV heart failure within one year. RESULTS: The primary outcome occurred in 271 of 2618 patients (10.4%) in the EMI group vs. 322 of 5242 patients (6.1%) in the PIS group [AdjustedHR, 1.54; 95% CI, 1.30 to 1.82; p < .001]. The primary outcome occurred in the thrombectomy and PCI alone groups in 131 of 1306 (10.0%) and 140 of 1312 (10.7%) patients with EMI [HR 0.94; 95% CI, 0.74-1.19] and 162 of 2633 (6.2%) and 160 of 2609 (6.1%) patients with PIS [HR 1.00; 95% CI, 0.81-1.25], respectively (pinteraction = 0.679). CONCLUSIONS: Patients with the EMI ECG pattern proved to have an increased rate of the primary outcome within one year compared to the PIS pattern. Routine manual thrombectomy did not reduce the risk of primary outcome within the different dynamic ECG patterns. The PIS/EMI dynamic ECG classification could help to triage patients in case of simultaneous STEMI patients with immediate need for pPCI.

Agreement between cardiologists and fellows in interpretation of ischemic electrocardiographic changes in acute myocardial infarction.

BACKGROUND: Time from symptom onset may not be the best indicator for choosing reperfusion therapy for patients presenting with acute ST-elevation myocardial infarction (STEMI); consequently ECG-based methods have been developed. METHODS: This study evaluated the inter-observer agreement between experienced cardiologists and junior doctors in identifying the ECG findings of the pre-infarction syndrome (PIS) and evolving myocardial infarction (EMI). The ECGs of 353 STEMI patients were independently analyzed by two cardiologists, one fellow in cardiology, one fellow in internal medicine and a medical student. The last two were given a half-hour introduction of the PIS/EMI-algorithm. RESULTS: The inter-observer reliability between all the investigators was found to be good according to kappa statistics (κ 0.632-0.790) for the whole study population. When divided into different subgroups, the inter-observer agreements were from good to very good between the cardiologists and the fellow in cardiology (κ 0.652 -0.813) and from moderate to good (κ 0.464-0.784) between the fellow in internal medicine, medical student and the others. CONCLUSIONS: The PIS and EMI ECG patterns are reliably identified by experienced cardiologists and can be easily adopted by junior doctors.

Electrocardiographic presentation of global ischemia in acute coronary syndrome predicts poor outcome.

BACKGROUND: Global ischemia (GI) electrocardiogram (ECG), wide-spread ST depression with inverted T waves maximally in leads V(4-5), and lead aVR ST elevation (STE), is a marker of an adverse outcome in patients with non-ST elevation acute coronary syndromes (ACS), perhaps because this pattern is indicative of left main stenosis. The prognostic value of this ECG pattern has not been established. AIMS: The distribution of ECG changes and the prognostic value of the GI ECG were studied. METHODS: ECGs of consecutive patients admitted with suspected ACS (n = 1,188) were classified into seven ECG categories: STE, Q waves without STE, left bundle branch block, left ventricular hypertrophy, GI ECG, other ST depression and/or T wave inversion, and other findings. RESULTS: The GI ECG pattern predicted a high rate (48%) of composite end-points (mortality, re-infarction, unstable angina, resuscitation, or stroke) at 10-month follow-up compared to the other ECG categories (36%) (HR 1.78; CI 95% 1.31-2.41; P < 0.001). In multivariate analysis, the GI ECG pattern was associated with a higher rate of composite end-points (HR 1.40; CI 95% 1.02-1.91; P = 0.035). The multivariate analysis furthermore identified age, creatinine level, and diabetes as independent predictors of prognosis. CONCLUSIONS: The GI ECG pattern predicted an unfavorable outcome, when compared to other ECG patterns in patients with ACS.

Factors associated with failure to identify the culprit artery by the electrocardiogram in inferior ST-elevation myocardial infarction.

BACKGROUND: Right and left circumflex coronary artery occlusions cause inferior myocardial infarction. To improve the targeting of diagnostic and therapeutic measures individually, factors interfering with identification of the culprit artery by the electrocardiogram (ECG) were explored. METHODS: Patients with inferior preinfarction syndrome (n = 266) were included to the Danish Trial in Acute Myocardial Infarction-2 substudy. The culprit vessel was predicted by the ECG, and findings were correlated with angiography. Factors associated with false identification of the culprit artery by the ECG were examined. RESULTS: Electrocardiogram criteria for right coronary artery occlusion to predict coronary angiography findings had sensitivity, specificity, and positive and negative predictive values of 95%, 52%, 84%, and 81%. For left circumflex coronary artery occlusion, the corresponding values were 51%, 93%, 70%, and 85%, respectively. False ECG identification of the culprit artery was independently associated with left coronary dominance (P < .001; odds ratio [OR], 22.0; 95% confidence interval [CI], 7.2-67.0), multivessel disease (P = .035; OR, 2.2; 95% CI, 1.1-4.7), and absence of proximal occlusion pattern in the ECG (P = .003; OR, 4.0; 95% CI, 1.6-9.8). CONCLUSIONS: Left coronary artery dominance, multivessel disease, and absence of ECG signs of proximal culprit lesion are associated with failure to predict the culprit artery of inferior myocardial infarction by the 12-lead ECG.

The etiology and prognostic significance of cardiac troponin I elevation in unselected emergency department patients.

BACKGROUND: Cardiac troponin elevations are associated not only with acute coronary syndromes (ACS) but also with multiple other cardiac and non-cardiac conditions. STUDY OBJECTIVES: To investigate the etiology and clinical significance of cardiac troponin I elevations in an unselected Emergency Department (ED) patient cohort. METHODS: The study population consisted of 991 consecutive troponin-positive patients admitted to the ED of a university hospital with ACS as the presumptive diagnosis. Cardiac troponin I was measured on admission and a follow-up sample was obtained at 6-12 h. Clinical diagnosis was ascertained retrospectively using all the available information including electrocardiogram, clinical data, laboratory tests, and available coronary angiograms. RESULTS: At admission, 805 (81.2%) patients were already troponin positive; of these, the troponin elevation was related to myocardial infarction (MI) in 654 (81.2%) patients. Finally, 83.0% of the troponin elevations were due to MI, 7.9% were related to other cardiac causes, and 9.1% to non-cardiac diseases. The leading non-cardiac causes were pulmonary embolism, renal failure, pneumonia, and sepsis. Non-cardiac patients with elevated troponin I at admission showed significantly higher in-hospital mortality (26.7% vs. 13.4%, p = 0.002) compared to cardiac patients. CONCLUSION: Elevated troponin levels for reasons other than MI are common in the ED and are a marker of poor in-hospital prognosis.

Value of the 12-lead electrocardiogram to define the level of obstruction in acute anterior wall myocardial infarction: correlation to coronary angiography and clinical outcome in the DANAMI-2 trial.

BACKGROUND: Acute anterior myocardial infarction (MI) caused by proximal occlusion of the left anterior descending coronary artery (LAD), is associated with unfavourable outcome and should be recognized by simple noninvasive methods like the 12-lead electrocardiogram (ECG). METHODS: In a prospective post-hoc DANAMI-2 substudy we compared two pre-specified ECG patterns to determine the level of LAD occlusion. The ECG findings were correlated to coronary angiography from the acute phase. The impact on clinical outcome of ECG and angiographic signs of proximal versus distal LAD occlusion was studied. RESULTS: In 146 patients without confounding factors on the ECG, either ST-elevation>or=0.5 mm in lead aVL or any ST-elevation in lead aVR in association with precordial ST-segment elevation in at least two contiguous leads (including V2, V3 or V4) had a sensitivity of 94%, specificity of 49%, positive predictive value of 85% and negative predictive value of 71% to predict a proximal LAD lesion. Surprisingly, ECG or angiographic signs of lesion proximality were not associated with worse outcome at 30 day or 2.7 year follow-up. CONCLUSIONS: The site of occlusion in the LAD could be reliably predicted by 12-lead ECG in patients with acute anterior MI. The prognostic significance of the level of occlusion in the LAD in the modern era of acute ST-elevation MI treatment should be reassessed.

Electrocardiogram patterns in acute left main coronary artery occlusion.

Acute coronary syndrome with subtotal occlusion of the left main coronary artery is rather frequently encountered in the catheterization laboratory, whereas survival to hospital admission of sudden total occlusion of the left main coronary artery is rare. The typical electrocardiographic (ECG) finding in cases with preserved flow through the left main is widespread ST-segment depression maximally in leads V4-V6 with inverted T waves and ST-segment elevation in lead aVR. In acute myocardial ischemia without (or with minor) myocardial necrosis, the ECG pattern is transient, whereas persistent ECG changes, usually without development of Q waves, are indicative of myocardial injury. In acute total left main occlusion, severe ischemia may be manifested in the ECG by life-threatening tachyarrhythmias, conduction disturbances, and ST-segment deviation. Because of the potential for life-saving therapeutic options by invasive therapy, the ECG markers of the serious condition should be recognized by the medical profession. Left main occlusion should be suspected in severely ill patients with widespread ST-segment depressions, especially in leads V4-V6 with inverted T waves or ST elevation involving the anterior precordial leads and the lateral extremity leads I and aVL. In addition, lead aVR ST elevation accompanied by either anterior ST elevation or widespread ST-segment depression may indicate left main occlusion.

Detection of proximal coronary occlusion in acute coronary syndrome: a feasibility study using computerized electrocardiographic analysis.

BACKGROUND: Rapid identification of a proximal occlusion site of a major coronary artery is of paramount importance in the care of myocardial infarction (MI). It is increasingly recognized that routine electrocardiogram (ECG) can be used for that purpose, provided that expert interpretation is available. Computer-based signal analysis has potential to enhance early ECG interpretation but its performance must be validated against manual algorithms. We therefore set out to develop a computer-assisted model to detect proximal occlusion of the left anterior descending coronary artery (LAD) in patients with suspected acute coronary syndrome (ACS). METHODS: Based on manual anatomical interpretation of the ECG, obtained from 216 consecutive patients who were admitted due to suspected ACS, an automatic computerized ECG model to detect LAD occlusion was constructed. Agreement between manual evaluation of the ECG by two cardiologists and a computerized ECG algorithm to detect occlusion of the LAD and the site of occlusion was determined. RESULTS: Using an expert electrocardiographer's anatomical interpretation as the gold standard, the computer model recognized patients fulfilling ECG criteria for any occlusion of the LAD with a specificity of 99% and a sensitivity of 67% (kappa= 0.71). However, proximal LAD occlusion was detected with 100% specificity and 86% sensitivity (kappa= 0.72). The computer program detected a distal occlusion in the LAD with a specificity of 99% and a sensitivity of 40% (kappa= 0.72). CONCLUSIONS: Computerized anatomical interpretation of the ECG is feasible and allows detection of a proximal LAD occlusion with excellent accuracy.

The electrocardiographic window of opportunity to treat vs. the different evolving stages of ST-elevation myocardial infarction: correlation with therapeutic approach, coronary anatomy, and outcome in the DANAMI-2 trial.

AIMS: The aim of the study was to assess two distinct 12-lead electrocardiogram (ECG) patterns and their prognostic value with respect to reperfusion strategy. METHODS AND RESULTS: In a DANAMI-2 substudy (n = 1522), we defined the pre-infarction syndrome (PIS) as ST-elevation accompanied by positive T waves and evolving myocardial infarction (EMI) as pathological Q waves and/or negative T wave. We used a composite of death, clinical re-infarction, or disabling stroke at median 2.7 year follow-up. A higher overall event rate was observed in the EMI group compared with the PIS group [11.4 (9.4-13.9) and 6.9 (6.0-8.0) per 100 person-years, respectively, ratio of the rate (RR) 1.6, P < 0.001]. The EMI pattern was independently predictive of adverse outcome in multivariable analysis (hazard ratio 1.52, confidence interval 1.01-2.30, P = 0.04). The PIS pattern (n = 952) was associated with lower overall event rate in patients treated with primary percutaneous coronary intervention (PCI) compared with fibrinolytic therapy (FT) [5.5 (4.4-6.9) and 8.5 (7.0-10.4) per 100 person-years, respectively, RR = 0.6, P = 0.004]. No significant difference in the outcome between treatment strategies was observed in the EMI group as a whole. However, in patients with anterior EMI without ECG signs of reperfusion, superiority of primary PCI was driven by a 51% reduction in the relative risk of composite endpoint (P = 0.008). CONCLUSION: More detailed ECG analysis, involving also Q- and T-wave morphology, is useful for rapid identification of high-risk patients in whom every effort should be made to transfer for primary PCI, or vice versa, for identifying low-risk patients in whom FT might be an alternative option.

Mortality of patients with acute coronary syndromes still remains high: a follow-up study of 1188 consecutive patients admitted to a university hospital.

BACKGROUND: Based on randomized clinical trials, mortality of acute coronary syndrome (ACS) has been considered to be relatively low. The prognosis of clinical presentations of ACS in real-life patient cohorts has not been well documented. AIM: The aim of this study was to evaluate actual clinical outcome across the whole spectrum of ACS in a series of unselected prospectively collected consecutive patients from a defined geographical region, all admitted to one university hospital. METHODS: A total of 1188 patients with ST-elevation myocardial infarction (STEMI), non-ST-elevation MI (NSTEMI) or unstable angina pectoris (UA) were included. Results. In-hospital mortality was 9.6%, 13% and 2.6% (P<0.001) and mortality at a median follow-up of 10 months 19%, 27% and 12% (P<0.001), for the three ACS categories, respectively. In multivariate Cox regression analysis age, diabetes mellitus type 1, diuretic use at admission, creatinine level, lower systolic blood pressure, STEMI and NSTEMI ACS category were associated with higher mortality during follow-up. CONCLUSIONS: In an unselected patient cohort, short-term mortality of MI patients, especially those classified as NSTEMI, still was high despite increasing use of proven treatment modalities.

The ECG pattern of isolated right ventricular infarction during percutaneous coronary intervention.

Isolated right ventricular infarction (RVI) is a rare event. The electrocardiographic (ECG) pattern of RVI, ST-elevation in lead V4R and in anterior chest leads V1-3 is similar to that of a proximal occlusion of a small, nondominant right coronary artery (RCA). The ECG changes may be misinterpreted as signs of infarction of the anterior wall. This paper describes a case of isolated temporary occlusion of the major side branches of the RCA during percutaneous coronary intervention, recognized by angiography findings and typical ECG changes. This case demonstrates how one might avoid wrong decisions even in the catheterization laboratory by putting attention to the anatomical interpretation of the ECG.

Electrocardiographic presentations of left main or severe triple vessel disease in acute coronary syndromes--an overview.

The prognosis of high-risk patients with non-ST-elevation acute coronary syndrome can be improved by invasive therapy. Taking into account the large number of patients with symptoms suggestive of acute coronary syndrome, the heterogeneity of the population and the increased risk of events shortly after the onset of symptoms, a strategy for initial evaluation and treatment is essential. The electrocardiogram (ECG) is the most accessible and widely used diagnostic tool for patients with symptoms suggestive of acute myocardial ischaemia. The ECG is almost never normal during episodes of rest angina. A specific ECG pattern, transient ST-segment depression and negative T waves maximally in leads V4-5, is associated to left main or severe triple vessel disease, and should alert the treating physician to admit the patient for immediate invasive evaluation. The ECG finding is a result of severe wide-spread subendocardial ischaemia.

Recording lead V(4)R is associated to enhanced use of fibrinolytic therapy in acute myocardial infarction.

BACKGROUND: ST-segment elevation in the right-sided chest lead V(4)R in inferior wall myocardial infarction is recognized as a sign of proximal occlusion of the right coronary artery with evolving right ventricular myocardial infarction. Our objective is to study how often lead V(4)R is recorded in clinical practice and how this might be associated with use of reperfusion therapy and outcome of patients. METHODS: Recording of lead V(4)R in 814 consecutive patients with acute myocardial infarction, administration of therapy, and outcome of the patients during a median follow-up of 285 days (174-313 days) were studied. RESULTS: V(4)R was recorded in 52% of patients with inferior ST-elevation myocardial infarction. Patients with V(4)R recorded were more likely to receive fibrinolytic therapy compared with patients without recording (65% vs 51%; P = .035). In multivariate analysis, recording of lead V(4)R (odds ratio [OR] 1.6, 95% confidence interval [CI] 1.1-2.2; P = .006), along with age (P < .001), previous myocardial infarction (OR 2.2, 95% CI 1.3-3.5; P = .002), and diabetes (OR 3.9, 95% CI 1.1-2.4; P = .03) correlated to the use of reperfusion therapy. Patients with lead V(4)R recorded had less (P = .055) reinfarction, unstable angina, stroke, and/or death during follow-up. CONCLUSIONS: Lead V(4)R was recorded in only half of patients with inferior ST-elevation myocardial infarction. Patients with V(4)R recorded were more likely to receive thrombolytic therapy than those without recording of the additional chest lead.

Comparative accuracy of manual versus computerized electrocardiographic measurement of J-, ST- and T-wave deviations in patients with acute coronary syndrome.

Accurate and rapid electrocardiographic interpretation is of crucial importance in acute coronary syndrome (ACS). Computerized electrocardiographic algorithms are often used in out-of-hospital settings. Their accuracy should be carefully validated in ACS, particularly in ST-elevation myocardial infarction. This study evaluated the comparative accuracy of lead-specific computer-based versus manual measurements of the J-point, ST-segment, and T-wave deviations in standard 12-lead electrocardiograms (ECGs) (excluding lead aVR). Sixty-nine consecutive patients with suspected ACS were included. The interobserver reliability in the determination of ST-segment deviation>or=0.2 mV in leads V2 and V3 was very good (kappa=0.94 and 0.93, respectively). Agreement between a cardiologist and the computer regarding ST elevation>or=0.2 mV in lead V2 was moderate (kappa=0.72) and in V3 was very good (kappa=0.85). For ST depression or elevation>or=0.05 mV in lead LIII, agreement was good and moderate (kappa=0.79 and 0.51, respectively). Bland-Altman analysis demonstrated clinically acceptable limits of agreement comparing measurements of the J point and the T wave, but clinically inadequate limits of agreement with respect to ST-segment deviation, between the electrocardiographer and the computer. The optimal cut-off points were 0.115 mV (sensitivity 89%, specificity 98%) for the computer program to detect ST elevation>or=0.2 mV and 0.045 mV (sensitivity 74%, specificity 99%) for revealing ST elevation>or=0.1 mV. It was found that automatically measured ST-segment deviations were smaller than those manually measured. In conclusion, a correction should be performed to obtain optimal results in the automated analysis of ECGs, because the results have important implications for clinical decision making.