QRS-T-angle in Patients with ST-Segment Elevation Myocardial Infarction (STEMI) - a Comparison with Cardiac Magnetic Resonance Imaging

Significance of QRS scoring system in left ventricular function recovery after acute myocardial infarction

AIMS

The Selvester scoring system has been derived from ECG parameters for estimating infarct size. However, there is still a lack of evidence for Selvester score as an alternative to cardiac magnetic resonance (CMR) myocardial injury makers for risk stratification and prediction of left ventricular function (LVF) recovery among patients with ST-segment elevation myocardial infarction (STEMI).

METHODS AND RESULTS

This multicentre observational study enrolled 328 STEMI patients (88.4% men, 57.3 ± 10.6 years of age) undergoing CMR examination 1 week post-reperfusion therapy. Patients with baseline left ventricular ejection fraction (LVEF) < 50% underwent a follow-up CMR 6 months later, categorized into baseline normal LVF (ejection fraction [EF] ≥ 50% at baseline, n = 155); recovered LVF (EF < 50% at baseline and ≥50% after 6 months, n = 69); and reduced LVF (EF < 50% at baseline and after 6 months, n = 104). The median follow-up was 4 (3-4) years for all patients, with 61 patients experiencing major adverse cardiovascular event (MACEs). Patients with reduced LVF had a higher risk of MACEs than those with baseline normal LVF (P = 0.01), while the recovered LVF group had no significant difference (P > 0.05). A Selvester score >10 doubled the risk of MACEs in patients with systolic dysfunction (1.91 [1.02 to 3.58], P = 0.04). Additionally, Selvester score, baseline LVEF, transmural infarction, and peak CK-MB were independent predictors of recovered LVF, with Selvester score providing incremental predictive value to peak CK-MB in predicting recovered LVF (∆AUC = 0.07, P < 0.05).

CONCLUSIONS

The Selvester score improves risk stratification among STEMI patients beyond LVEF and provide independent and incremental information to clinical parameters in predicting recovered LVF.

[Factors associated with an increase in spatial and frontal QRS-T angles in patients with anterior myocardial infarction]

Aim    To determine existence of a relationship between any clinical, echocardiographic and coronarographic factors and increased spatial QRS-T (sQRS-T) angle and frontal QRS-T (fQRS-T) angle in patients with anterior myocardial infarction.Material and methods    This study included 137 patients aged 62 [53; 72] years with anterior acute myocardial infarction managed at the A.L. Myasnikov Institute of Clinical Cardiology. fQRS-T was calculated as the module of difference between the frontal plane QRS complex axis and the T wave axis. sQRS-T was calculated as a spatial angle between QRS and T integral vectors from a synthesized vectorcardiogram.Results    fQRS-T values for a group (median [25th; 75th percentile]) were 81 [37; 120]°; sQRS-T values were 114 [80; 141]°. The correlation coefficient between fQRS-T and sQRS-T values was 0.41 (p&lt;0.001). fQRS-T weakly but statistically significantly correlated with patients' age (r=0.28; p=0.001), left ventricular ejection fraction (LV EF, r= -0.22; p=0.01), and glomerular filtration rate (r=-0.32; p=0.0002). sQRS-T weakly but statistically significantly correlated with left ventricular end-diastolic dimension (r=0.24; p=0.0048), LV EF (r=-0.28; p=0.0009), and the number of affected segments according to echocardiography data (r=0.27; p=0.002). fQRS-T values were significantly higher in the presence of concurrent arterial hypertension. sQRS-T values were significantly higher in the presence of a history of chronic heart failure. Both fQRS-T and sQRS-T values increased with increasing number of affected blood vessels and Killip class of acute heart failure.Conclusion    In patients after anterior acute myocardial infarction, increases in fQRS-T and sQRS-T are associated with more severe damage of the vasculature, decreased LV EF, and, thus, more severe clinical course of disease.

Prognostic significance of QRS distortion and frontal QRS-T angle in patients with ST-elevation myocardial infarction

BACKGROUND

QRS distortion (G3I) and frontal QRS-T angle (fQRS-T angle) are both electrocardiographic (ECG) signs of ongoing ischemia and depolarization-repolarization heterogeneity, which always occur in patients with ST-segment elevation acute myocardial infarction (STEMI).

METHODS

We retrospectively collected 592 STEMI patients who underwent coronary angiography and follow-up for 42 months. 1. We divided the patients into two groups according to whether they had G3I on admission, compared the differences in examination data and endpoint events between these two groups. 2. Group patients according to whether the endpoint events happened in hospital, at 12 and 42 months, compare whether there is a difference in fQRS-T angle at the same time point, and find out the predictive cutoff value of all-cause death. 3. Combined G3I and fQRS-T angle together to enhance the predictive value.

RESULTS

G3I and fQRS-T angle are both independent risk factors for all-cause death in STEMI patients within 12 months (G3I P = 0.014, fQRS-T angle P < 0.001) and within 42 months (P < 0.001). The cutoff values of fQRS-T angle for predicting all-cause death are 66.5° at 12 months and 90.5° at 42 months. When G3I and fQRS-T angle are combined used to predict the mortality, the specificity is significantly improved, but the sensitivity decreased.

CONCLUSIONS

G3I and fQRS-T angles are valuable in the prognostic assessment of STEMI patients, especially when combined. These findings help clinicians to identify high-risk patients early for more aggressive treatment.

Association of QRS-T angle and Late Gadolinium Enhancement in patients with a Clinical Suspicion of Myocarditis

Objective: To investigate the association of a wide QRS-T angle on the surface ECG and late gadolinium enhancement on contrast-enhanced cardiovascular magnetic (CMR) imaging in patients with clinically suspected myocarditis. Background: Diagnosis and risk stratification in patients with suspected myocarditis is particularly challenging due to a great spectrum of clinical presentations. Late gadolinium enhancement (LGE) visualizes myocardial necrosis and fibrosis in patients with biopsy-proven myocarditis. The presence or absence of late gadolinium enhancements in these patients is prognostically meaningful. The QRS-T angle from the surface ECG, on the other hand, may serve as a simple and easily available risk marker in suspected myocarditis. Methods: We enrolled 97 consecutive patients that were referred to CMR imaging for a clinical suspicion of myocarditis. All patients obtained a standardized digital 12-lead ECG for the calculation of the QRS-T angle and underwent contrast-enhanced CMR imaging. Patients were divided into two groups according to the absence or presence of LGE on CMR. Results: 78 of 97 patients with suspected myocarditis had LGE on CMR. Patients with LGE had wider QRS-T angles as compared to the patient group without LGE (53.95-47.5 vs. 26.2-21.2; p<0.001). The sensivity, specificity, negative predictive value and positive predictive value for a QRS-T angle above 90 degrees for LGE positive myocarditis were 16.5%, 100%, 24.7%, and 100%, respectively. Conclusion: A wide QRS-T angle of 90 degrees or more is linked to myocardial fibrosis or necrosis (late gadolinium enhancement) in patients with suspected myocarditis.