Reciprocal change in ST segment in acute myocardial infarction: correlation with findings on exercise electrocardiography and coronary angiography

Rapid weather changes are associated with daily hospital visitors for atrial fibrillation accompanied by abnormal ECG repolarization: a case-crossover study

BACKGROUND

Atrial fibrillation (AF) is highly prevalent in the population, yet the factors contributing to AF events in susceptible individuals remain partially understood. The potential relationship between meteorological factors and AF, particularly with abnormal electrocardiograph (ECG) repolarization, has not been adequately studied. This case-crossover study aims to investigate the association between meteorological factors and daily hospital visits for AF with abnormal ECG repolarization in Shanghai, China.

METHODS

The study cohort comprised 10,325 patients with ECG-confirmed AF who sought treatment at Shanghai Sixth People's Hospital between 2015 and 2018. Meteorological and air pollutant concentration data were matched with the patient records. Using a case-crossover design, we analyzed the association between meteorological factors and the daily count of hospital visitors for AF with abnormal ECG repolarization at our AF center. Lag analysis models were applied to examine the temporal relationship between meteorological factors and AF events.

RESULTS

The analysis revealed statistically significant associations between AF occurrence and specific meteorological factors. AF events were significantly associated with average atmospheric pressure (lag 0 day, OR 0.9901, 95% CI 0.9825-0.9977, P < 0.05), average temperature (lag 1 day, OR 0.9890, 95% CI 0.9789-0.9992, P < 0.05), daily pressure range (lag 7 days, OR 1.0195, 95% CI 1.0079-1.0312, P < 0.01), and daily temperature range (lag 5 days, OR 1.0208, 95% CI 1.0087-1.0331, P < 0.01). Moreover, a significant correlation was observed between daily pressure range and daily temperature range with AF patients, particularly those with abnormal ECG repolarization, as evident in the case-crossover analysis.

CONCLUSION

This study highlights a significant correlation between meteorological factors and daily hospital visits for AF accompanied by abnormal ECG repolarization in Shanghai, China. In addition, AF patients with abnormal ECG repolarization were found to be more vulnerable to rapid daily changes in pressure and temperature compared to AF patients without such repolarization abnormalities.

Serial analyses of ventricular late potentials in patients with reciprocal ST segment changes during acute myocardial infarction

The aim of this study was to determine whether successful reperfusion may alter substrate that is responsible for late potentials in the presence or absence of reciprocal ST segment changes (RC). The study population consisted of 50 patients (27 with RC and 23 without RC) with anterior acute myocardial infarction (AMI) undergoing successful thrombolytic therapy (TT). The presence of reciprocal changes was defined as ST-segment depression >1 mm, measured 80 ms after the J point in at least 2 leads other than those reflecting the infarct on admission ECG. All patients were evaluated with coronary angiography at predischarge. Signal averaged ECG (SAECG) recordings were obtained before and 10 days after TT. Baseline characteristics, SAECG findings, and angiographic data were similar between the groups. The only different baseline finding was the time from symptom onset to TT (204 +/- 150 minutes for patients with RC vs 312 +/- 174 minutes for patients without RC. P = 0.021). After TT, RMS values improved in patients with RC (from 35 +/- 17 microV to 43 +/- 14 microV, P = 0.038) and LAS and RMS were significantly better in this group. However, patients without RC did not show any changes in SAECG parameters after TT. LV ejection fraction (10th day) was better in patients with RC (45 +/- 11% vs 39 +/- 6%, P = 0.014). The frequency of ventricular arrhythmias during the hospitalization period was also similar between the groups. Reciprocal ST depression that regresses simultaneously with the infarction related ECG changes after TT in anterior AMI seems to be related to the time that has elapsed since the symptom onset. The improvement in SAECG parameters after TT in these patients is probably the result of earlier reperfusion leading to less myocardial damage.

Value of the initial electrocardiogram in patients with inferior-wall acute myocardial infarction for prediction of multivessel coronary artery disease

BACKGROUND

Patients with inferior-wall acute myocardial infarction (AMI) who have ST-segment depression in the left precordial leads (LSTD+) on the initial electrocardiogram were reported to have more diffuse coronary artery disease (CAD) than had those without this finding (LSTD-). This suggests that LSTD+ patients may need extensive revascularization interventions more often than do LSTD- patients. However, this has not yet been confirmed.

OBJECTIVE

To compare the coronary angiographic findings and treatment strategies for patients with inferior-wall AMI according to the LSTD pattern.

METHODS

The clinical outcomes and the angiographic findings for 238 consecutive patients aged < or = 75 years who had been admitted to our hospital between 1 February 1995 and 1 February 1997 with inferior-wall AMI were retrospectively analyzed. The patients were divided into two groups according to the pattern of precordial ST-segment depression: LSTD+, ST-segment depression in leads V4-V6; and LSTD-, absence of this finding. All patients were treated according to current practice guidelines including with thrombolysis and revascularization interventions.

RESULTS

The final study population included 217 patients; 83 were LSTD+ and 134 were LSTD-. All underwent coronary angiography within 30 days of the infarction. Compared with LSTD- patients, LSTD+ patients tended to be older (mean age 62.7 +/- 11.7 versus 58.3 +/- 9.6 years, P = 0.004), and had higher incidences of hypertension (39.8 versus 24.6%, P = 0.019) previous myocardial infarction (45.8 versus 20.1%, P = 0.0001) and congestive heart failure (21.7 versus 3.7%, P = 0.00008). Three-vessel CAD was much more common, and single-vessel CAD much less common, in the LSTD+ than in LSTD- group (62.7 versus 13.4% and 8.4 versus 50.7%, P < 0.00001 for both). Coronary-artery-bypass surgery and multivessel percutaneous coronary interventions (PCI) were used in treating 65.1% of the LSTD+ versus only 6.0% of the LSTD- patients (P < 0.00001), whereas single-vessel PCI was used in treating 71.6% of the LSTD- patients versus only 24.1% of the LSTD+ patients (P < 0.00001). Thus, the LSTD- pattern predicted single-vessel disease and single-vessel PCI only, whereas the LSTD+ pattern was predictive of multivessel CAD and of use of coronary-artery-bypass surgery or multivessel PCI (predictive values of 94.0 and 65.1%, respectively).

CONCLUSIONS

Among patients with inferior-wall AMI, left precordial ST-segment depression predicts a very high prevalence of multivessel CAD and use of extensive revascularization interventions. The absence of this finding predicts nondiffuse CAD and lack of a need for extensive revascularization.

Correlation of angiographic findings and right (V1 to V3) versus left (V4 to V6) precordial ST-segment depression in inferior wall acute myocardial infarction

This study assessed whether differences in the underlying mechanisms for various patterns of precordial ST-segment depression with inferior acute myocardial infarction (AMI) are associated with poorer prognoses. We studied 1,155 patients with inferior AMI who underwent thrombolysis in the Global Utilization of Streptokinase and TPA for Occluded arteries (GUSTO-I) angiographic substudy: those without precordial ST depression (n = 412; 35.7%), those with maximum ST depression in leads V1 to V3 (n = 547; 47.4%), and those with maximum ST depression in leads V4 to V6 (n = 196; 17.0%) on admission electrocardiogram. We compared the infarct-related artery, presence of left anterior descending or multivessel coronary artery disease, and left ventricular function among groups. Patients with maximum ST depression in leads V4 to V6 more often had 3-vessel disease (26.0%) than those without precordial ST depression (13.5%) or those with ST depression in leads V1 to V3 (15.7%; p = 0.002), and they had a lower ejection fraction (median 54% vs 60% and 55%, respectively; p <0.001). Patients with maximum ST depression in leads V1 to V3 less often had AMIs due to proximal right coronary artery obstruction (23.9%) than patients without precordial ST depression (35.2%) or those with ST depression in leads V4 to V6 (40.0%; p = 0.001) and had larger AMIs as estimated by peak creatine kinase. Different patterns of precordial ST depression are associated with distinctive coronary anatomy. ST depression in leads V4 to V6, but not V1 to V3, confers a greater likelihood of multivessel coronary artery disease.

Maximal precordial ST-segment depression in leads V4-V6 in patients with inferior wall acute myocardial infarction indicates coronary artery disease involving the left anterior descending coronary artery system

BACKGROUND

In inferior wall acute myocardial infarction, maximal ST-segment depression in left precordial leads (V4-V6) has been shown to be associated with increased in-hospital mortality, presumably due to coronary artery disease involving the left anterior descending coronary artery system.

METHODS

We measured ST-segment deviation from baseline in the initial electrocardiogram of patients with inferior wall acute myocardial infarction, who subsequently underwent coronary angiography during their in-hospital stay. Patients were divided into three groups: (I) No precordial ST-segment depression (n = 34). (II) Maximal precordial ST-segment depression in leads V1-V3 (n = 44). (III) Maximal precordial ST-segment depression in leads V4-V6 (n = 14).

RESULTS

The left anterior descending coronary artery or its diagonal branch were stenosed (> 50%) in 32%, 41%, and 71% of patients in groups I, II, and III, respectively (p = 0.04), and severely stenosed (> 70%) in 18%, 18% and 57% of patients in the respective groups (p = 0.007).

CONCLUSION

In patients with inferior wall acute myocardial infarction, maximal precordial ST-segment depression in leads V4-V6 is suggestive of severe coronary artery disease involving the left anterior descending coronary artery or its diagonal branch.

Prognostic significance of precordial ST segment depression during inferior myocardial infarction in the thrombolytic era: results in 16,521 patients

OBJECTIVES

We examined the prognostic significance of precordial ST segment depression among patients with an acute inferior myocardial infarction.

BACKGROUND

Although precordial ST segment depression has been associated with a poor prognosis, this correlation has not been adequately quantified, partly because of small sample sizes and methodologic limitations in previous studies.

METHODS

We examined the clinical and angiographic outcomes of 16,521 patients with an acute inferior myocardial infarction who underwent thrombolysis in the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO-I) study. Patients were classified into those without precordial ST segment depression (n = 6,422 [38.9%]), those with ST segment depression in leads V1 to V3 only (n = 5,850 [35.4%]), those with ST segment depression in leads V4 to V6 only (n = 876 [5.3%]) and those with ST segment depression in both leads V1 to V3 and leads V4 to V6 (n = 3,373 [20.4%]) on initial electrocardiography. Outcome measures included postinfarction complications (second- or third-degree heart block, congestive heart failure or shock) and 30-day and 1-year mortality.

RESULTS

Patients with precordial ST segment depression had larger infarctions, more postinfarction complications and a higher mortality rate than those without precordial ST segment depression (4.7% vs. 3.2% at 30 days; 5.0% vs. 3.4% at 1 year; both p < 0.001), regardless of whether ST segment depression was noted in leads V1 to V6 or in leads V4 to V6. The magnitude of precordial ST segment depression (sum of leads V1 to V6) added significant independent prognostic information after adjustment for clinical risk factors; the risk of 30-day mortality increased by 36% for every 0.5 mV of precordial ST segment depression.

CONCLUSIONS

Assessment of the magnitude of precordial ST segment depression is useful for acute risk stratification in patients with an inferior myocardial infarction.

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)

Early exercise testing after treatment with thrombolytic drugs for acute myocardial infarction: importance of reciprocal ST segment depression

OBJECTIVE

To investigate the clinical importance of reciprocal ST depression induced by exercise testing early after acute myocardial infarction in patients treated with thrombolysis.

DESIGN

Prospective observational study.

SETTING

District general hospital in London.

SUBJECTS

202 patients (170 men) aged 33-69 with acute myocardial infarction treated with thrombolysis.

MAIN OUTCOME MEASURES

All patients underwent exercise testing and coronary arteriography. ST depression induced by exercise was classified as either reciprocal (associated with ST elevation) or isolated (occurring on its own). The relation between reciprocal ST depression and the following end points was studied: characteristics of the infarct, left ventricular ejection fraction, extent of coronary artery disease on arteriography, and presence of angina induced by exercise.

RESULTS

Reciprocal ST depression occurred almost exclusively in Q wave infarctions and was associated with a lower overall ejection fraction than isolated ST depression. It tended to be associated with persistent occlusion of the coronary artery related to the infarct and did not indicate remote ischaemia due to multivessel coronary disease. Unlike isolated ST depression, reciprocal ST depression was not associated with angina induced by exercise.

CONCLUSIONS

Reciprocal ST depression induced by exercise is usually associated with extensive Q wave infarctions and persistent occlusion of the artery related to the infarct. It does not seem to indicate reversible ischaemia and should not be used as a non-invasive marker of multivessel disease in the assessment of requirements for further investigation soon after acute myocardial infarction.

Significance of reciprocal ST depression in acute myocardial infarction: a study of 258 patients treated by thrombolysis

OBJECTIVE

To investigate the clinical significance of reciprocal ST depression on the presenting electrocardiogram in patients with acute myocardial infarction treated by thrombolysis.

DESIGN

A prospective cohort analytical study.

SETTING

A London district general hospital.

SUBJECTS

Two hundred and fifty eight consecutive patients with acute myocardial infarction treated with thrombolysis.

INTERVENTIONS

All patients underwent treadmill stress testing after a mean (SEM) of 10 (3) days; 200 patients (78%) were referred for coronary arteriography at 30 (16) days.

MAIN OUTCOME MEASURES

Relation between reciprocal ST depression at presentation and several endpoints: time from start of chest pain to hospital presentation, electrocardiographic changes during early treadmill stress testing, presence of multivessel coronary disease, and clinical outcome in terms of recurrent ischaemic events (death, reinfarction, and unstable angina) during a 10 (range six to 12) month follow up.

RESULTS

Presentation was generally early, but in this group of patients reciprocal ST depression was significantly related to the time from the start of symptoms, those with reciprocal change presenting on average one hour earlier than those without. Although reciprocal change on the presenting electrocardiogram was weakly associated with ST depression on treadmill stress testing, it was not indicative of remote ischaemia as a result of multivessel coronary disease or high grade collateralisation of the infarct related artery. There was no association between reciprocal change and the incidence of recurrent ischaemic events.

CONCLUSION

Reciprocal ST depression on the presenting electrocardiogram seems to be a benign electrical phenomenon related to the time from the start of symptoms. It does not necessarily predict an adverse prognosis in patients treated by thrombolysis.

Precordial ST segment depression predicts a worse prognosis in inferior infarction despite reperfusion therapy. The Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) Study Group

The impact of associated precordial ST segment depression in inferior myocardial infarction on angiographic and clinical outcomes after thrombolytic therapy and selective coronary angioplasty was studied in 583 patients with acute myocardial infarction. Anterior infarction (Group I), inferior infarction with precordial ST segment depression (Group II) and inferior infarction without precordial ST segment depression (Group III) were present in 289, 135 and 159 patients, respectively. Precordial ST segment depression was more frequent in circumflex than right coronary infarct-related arteries (44 [71%] of 62 versus 91 [40%] of 230; p = 0.000). Although acute patency rates were not statistically different, there was a trend toward different patency rates at day 7 (Group I 88%, Group II 84%, Group III 80%; p = 0.089) partly because of insignificantly higher reocclusion rates in inferior infarction without precordial ST segment depression (Group I 11%, Group II 10%, Group III 18%, p = 0.104). Infarct zone regional wall motion (standard deviations/chord) in inferior infarction was lower with precordial ST segment depression, both acutely (Group I -2.8 +/- 0.9, Group II -2.5 +/- 1.2, Group III 2.0 +/- 1.1; p = 0.000) and at day 7 (Group I -2.2 +/- 1.1, Group II -2.3 +/- 1.1, Group III -1.9 +/- 1.3; p = 0.011). Precordial ST segment depression was associated with a lower ejection fraction in inferior infarction both acutely (Group I 47 +/- 11%, Group II 53 +/- 11%, Group III 58 +/- 9%; p = 0.000) and at day 7 (Group I 49 +/- 12%, Group II 53 +/- 10%, Group III 58 +/- 8%; p = 0.000). Complication rates tended to be higher in inferior infarction when precordial ST segment depression was present. Mortality rates for Groups I, II and III were 8%, 6% and 5%, respectively. These results suggest that precordial ST segment depression in inferior infarction predicts a worse ventriculographic and clinical outcome despite reperfusion therapy.

Importance of reciprocal ST segment depression in leads V5 and V6 as an indicator of disease of the left anterior descending coronary artery in acute inferior wall myocardial infarction

The purpose of this study was to determine the coronary angiographic correlations (specifically disease of the left anterior descending coronary artery) of reciprocal ST segment depression appearing during inferior acute myocardial infarction. Forty six patients (41 men and five women; mean age 56 years) were allocated into two groups based on the extent of precordial ST segment depression: widespread (V1-V6) ST depression v localised (V1-V4) ST depression. Patients with no reciprocal ST depression or patients with ST depression in V1-V4 but with ST elevation in V5 and V6 (inferolateral acute myocardial infarction) were excluded. All patients were catheterised during hospital admission for infarction. Twenty four of the 28 patients with ST depression in V1-V6 had significant lesions in the left anterior descending coronary artery whereas 16 of the 18 patients with ST depression in V1-V4 had insignificant or no lesions in the left anterior descending artery. The sensitivity, specificity, and positive and negative predictive values of widespread ST depression in predicting disease in the left anterior descending coronary artery were 92%, 80%, and 86% and 89% respectively. In patients with inferior acute myocardial infarction and precordial ST depression, the extent of ST depression is of clinical significance. Widespread (V1-V6) ST depression suggests disease of the left anterior descending coronary artery, whereas localised ST depression (V1-V4) indicates its absence.

Physiologic bases for anterior ST segment depression in patients with acute inferior wall myocardial infarction

Patients with acute inferior myocardial infarction commonly have ST segment depression in the anterior precordial leads. This may reflect either reciprocal changes from the inferior ST elevation or primary ST depression from additional anterior subendocardial ischemia. From a biophysical perspective reciprocal changes should be uniformly anticipated from basic dipole theory. Detection will vary with the size, location, orientation, and electrical intensity of the lesion and with the ECG lead system deployed to register the anterior changes. Alternatively, acute occlusion of the right coronary artery may produce ischemia in the anterior left ventricular wall supplied by a stenotic anterior descending coronary artery. Anterior ischemia may result from the abnormal hemodynamics or the reduced collateral flow produced by acute right coronary artery occlusion. Thus both mechanisms are based on sound physiologic principles. A review of the clinical literature suggests that such patients represent a heterogeneous group. In some instances coexistent anterior ischemia is present, whereas in others the anterior ST depression is the passive reflection of inferior ST elevation augmented in many cases by a large infarct size or more extensive posterobasal or septal involvement.

The extent of coronary artery disease in diabetic patients with myocardial infarction: an ECG study

In 91 non-diabetics (age 63 +/- 12, mean +/- SD, years range 31-94 years) and 85 patients with known diabetes or clearly abnormal levels of HbA1c (age 66 +/- 10 years, range 36-87 years) electrocardiograms were analysed sequentially after acute myocardial infarction (AMI). There was no significant difference in infarct site between the two groups. Generalized ischaemic change without ST elevation was seen in 33% of diabetics and 22% of non-diabetics (p greater than 0.1). In patients with transmural AMI, cardiogenic shock (CGS) was significantly commoner in diabetics (relative risk 3.1, CL 1.2-8.1) but there was no difference in the frequency of reciprocal change between the two groups. In both diabetic and non-diabetic patients the development of cardiogenic shock was more frequently associated with the presence of reciprocal change, the difference reaching significance in the diabetic group (chi 2 = 4.4, p less than 0.05). Thus cardiogenic shock in both diabetic and non-diabetic patients with AMI may be associated with the presence of extensive coronary artery disease, but differences in the prevalence of extensive disease do not explain the predisposition of diabetic patients to CGS.

The aetiology and prognostic implications of reciprocal electrocardiographic changes in acute myocardial infarction

The relations between reciprocal ST segment depression in the electrocardiogram and infarct size and 10 year prognosis were studied in 315 patients who survived for at least 28 days after a first anterior or inferior myocardial infarction. ST depression was more common in inferior infarcts (72%) than in anterior (37%) ones. It occurred more frequently in complicated infarcts and in the presence of considerable ST elevation. Patients experiencing second or third degree heart block were significantly more likely to show reciprocal changes. The rise in peak cardiac enzyme concentration was higher in patients showing ST depression. In patients with ST depression, peak creatine kinase concentration was 46% higher, aspartate aminotransferase was 39% higher, and lactate dehydrogenase 29% higher after correction for site and complications. A discriminant function analysis selected infarct site, peak aspartate aminotransferase, and magnitude of ST elevation as predictors of the occurrence of ST depression. Age, severity, and smoking status did not significantly improve discrimination. Despite larger increases in peak enzyme concentrations patients with ST depression had marginally fewer subsequent episodes of unstable angina or fatal or non-fatal infarction and a marginally lower 10 year death rate. Neither difference was statistically significant. ST depression occurring early in the acute phase of myocardial infarction is likely to be a reflection of electrophysiological changes taking place at the site of the infarct that is manifested in the contralateral surface of the heart. Other causes, however, such as transient ischaemia at the site of the reciprocal changes or extension of the infarct to contiguous areas cannot be excluded in all cases.