Comparison of QT dispersion in patients with ST elevation acute myocardial infarction (STEMI) before and after treatment by streptokinase versus primary percutaneous coronary intervention (PCI)

Defective recovery of QT dispersion due to no-reflow following acute interventional therapy in patients with ST-segment elevation myocardial infarction

Background

Previous studies have suggested that adequate myocardial reperfusion after percutaneous coronary intervention (PCI) can improve the inhomogeneity of myocardial repolarization. However, it remains unclear whether no-reflow (NR) following emergency PCI involves disadvantages related to ventricular repolarization indices. The present study aimed to determine the effect of NR on QT dispersion (QTd) in patients with ST-segment elevation myocardial infarction (STEMI) and to evaluate the prognostic value of the relative reduction of QTd on ventricular arrhythmia events (VAEs).

Methods

A prospective case-control study was conducted. According to the inclusion criteria, 275 patients with STEMI who underwent primary PCI treatment at the First People's Hospital of Anqing affiliated to Anhui Medical University from January 2020 to May 2023 were enrolled. According to whether NR occurred during PCI, these patients were divided into two groups: an NR group and a non-NR group. Subsequently, the QT intervals were measured before and at 12 hours after PCI. Afterward, the QTd, corrected QTd (QTcd), and the relative reduction of QTd and QTcd 12 hours pre- and postprocedure (ΔQTd-R and ΔQTcd-R, respectively) were calculated. Finally, multivariable logistic regression analysis was performed to predict the risk of VAE occurrence.

Results

In the non-NR group, there was a significant decrease from baseline in postprocedure QTd (48±17 vs. 73±22 ms; P=0.009) and QTcd (54±19 vs. 80±23 ms; P=0.01); in contrast, the NR group showed no significant difference in QTd (64±20 vs. 75±23 ms; P=0.58) or QTd (70±22 vs. 82±26 ms; P=0.45). Furthermore, the ΔQTd-R and ΔQTcd-R were both lower in the NR group than in the non-NR group (P<0.05); however, the rate of VAEs was higher in the NR group than in the non-NR group (15.2% vs. 6.2%; P=0.02). The multivariable logistic regression analysis results revealed that each increase of 12% in ΔQTcd-R was an independent predictor of VAEs (odds ratio: 0.547; 95% confidence interval: 0.228-0.976).

Conclusions

The NR phenomenon following primary PCI in patients with STEMI leads to the defective recovery of QTd and QTcd. Furthermore, ΔQTcd-R can be viewed as an effective indicator for evaluating the myocardial repolarization inhomogeneity, and short-term clinical outcomes.

Effect of pulmonary embolism location on electrocardiological parameters

OBJECTIVE

Pulmonary thromboembolism is a disease with high morbidity and mortality. Various changes occur on the electrocardiogram secondary to pulmonary thromboembolism. The objective of this study was to investigate variations in QT dispersion, Tpeak-Tend duration, and Tpeak-Tend/QT ratio in relation to pulmonary thromboembolism localization and their impacts on 30-day mortality.

METHODS

This study was carried out in a tertiary emergency medicine clinic between December 1, 2019 and November 30, 2020. We evaluated correlations between radiological outcomes of patients, QT dispersions, T-wave dispersions, Tpeak-Tend durations, and Tpeak-Tend/QT ratios. We sought statistically significant disparities between these values, considering the presence or localization of pulmonary thromboembolism. The 30-day mortality in pulmonary thromboembolism-diagnosed patients was reassessed.

RESULTS

Electrocardiogramfindings revealed that T-wave dispersion (p<0.001), Tpeak-Tend duration (p=0.034), and Tpeak-Tend/corrected QT ratio (p=0.003) were lower in patients than controls. Conversely, QT dispersion (p=0.005) and corrected QT dispersion (p<0.001) were higher in patients.

CONCLUSION

Electrocardiogram findings such as T-wave dispersion, QT duration, Tpeak-Tend time, and Tpeak-Tend/corrected QT ratio can detect pulmonary thromboembolism. More studies with larger cohorts are required to further understand the role of QT and corrected QT dispersion in pulmonary thromboembolism patient mortality.

Effect of reperfusion strategy on QT dispersion in patients with acute myocardial infarction: Impact on in-hospital arrhythmia

BACKGROUND

Myocardial ischemia and ST-elevation myocardial infarction (STEMI) increase QT dispersion (QTD) and corrected QT dispersion (QTcD), and are also associated with ventricular arrhythmia.

AIM

To evaluate the effects of reperfusion strategy [primary percutaneous coronary intervention (PPCI) or fibrinolytic therapy] on QTD and QTcD in STEMI patients and assess the impact of the chosen strategy on the occurrence of in-hospital arrhythmia.

METHODS

This prospective, observational, multicenter study included 240 patients admitted with STEMI who were treated with either PPCI (group I) or fibrinolytic therapy (group II). QTD and QTcD were measured on admission and 24 hr after reperfusion, and patients were observed to detect in-hospital arrhythmia.

RESULTS

There were significant reductions in QTD and QTcD from admission to 24 hr in both group I and group II patients. QTD and QTcD were found to be shorter in group I patients at 24 hr than those in group II (53 ± 19 msec vs 60 ± 18 msec, P = 0.005 and 60 ± 21 msec vs 69+22 msec, P = 0.003, respectively). The occurrence of in-hospital arrhythmia was significantly more frequent in group II than in group I (25 patients, 20.8% vs 8 patients, 6.7%, P = 0.001). Furthermore, QTD and QTcD were higher in patients with in-hospital arrhythmia than those without (P = 0.001 and P = 0.02, respectively).

CONCLUSION

In STEMI patients, PPCI and fibrinolytic therapy effectively reduced QTD and QTcD, with a higher observed reduction using PPCI. PPCI was associated with a lower incidence of in-hospital arrhythmia than fibrinolytic therapy. In addition, QTD and QTcD were shorter in patients not experiencing in-hospital arrhythmia than those with arrhythmia.

The Effect of Percutaneous Coronary Intervention on QT Dispersion and the Association Between Them: A Systematic Review

Electrocardiography (ECG) parameters are significant in the prognosis of ischemia and other cardiovascular conditions. Reperfusion or revascularization techniques are essential in reestablishing blood flow to ischemic tissues. This study aims to demonstrate the association between percutaneous coronary intervention (PCI), a revascularization technique, and the electrocardiography (ECG) parameter, QT dispersion (QTd). We conducted a systematic review of the association between PCI and QTd through a literature search in three electronic databases, ScienceDirect, PubMed, and Google Scholar, for empirical studies published in English. Review Manager (RevMan) 5.4 (Cochrane Collaboration, Oxford, England) was used for statistical analysis. Of 3,626 studies, 12 articles met the inclusion criteria, enrolling a total of 1,239 patients. After a successful PCI procedure, QTd and corrected QT (QTc) tremendously reduced at various time intervals with statistical significance in most of the studies. There was a clear association between ECG parameters QTd, QTc, and corrected QT dispersion (QTcd), and PCI, in that there is a considerable reduction in these ECG parameters after PCI treatment.

The Comparison of QTc Dispersion Between Renal Transplant Recipients and Healthy Individuals

Introduction Cardiovascular diseases are the most common cause of death in patients with end-stage renal failure. The increase in QTc interval time and QT dispersion increases the risk of cardiac arrhythmia and mortality. In our study, QT and QTc dispersions (QTcd) of patients who underwent renal transplantation were compared with normal healthy individuals. Methods Electrocardiograms (ECGs) of 80 renal transplant recipients and 70 healthy individuals were taken. QTc dispersion was calculated by using the longest and the shortest QT interval and QT dispersion and Bazett's formula. Results When the groups were compared, similar QT dispersion and QTc dispersion were observed (control group and renal transplant recipient patients: 35 ± 17 ms and 36 ± 16 ms and 52 ± 18 ms and 54 ± 22 ms, respectively). Conclusion No statistical difference was observed between QT and QTc dispersions of renal transplant patients compared to healthy individuals. This result shows that the increase in QT dispersion and pathophysiological mechanisms observed frequently in uremic patients can be reversed by renal transplantation.

The association between QTc, QTd, TPE, and fragmented QRS before and after PPCI with hospital mortality in STEMI patients

INTRODUCTION

ST-elevation myocardial infarction (STEMI) is known to be associated with significant arrhythmia and consequent mortality. QT prolongation is a risk factor for arrhythmia in STEMI patients who underwent primary percutaneous coronary intervention (PPCI). The aim of this investigation was to evaluate the association of corrected QT interval (QTc), QT dispersion (QTd), T-wave peak to end (TPE), and fragmented QRS with mortality in these patients.

METHODS

Eligible patients with the characteristic symptoms of STEMI who underwent PPCI were included. QTc, QTd, TPE, and fragmented QRS were measured before and after the PPCI. These predictors were compared between patients who died during hospitalization and discharged patients.

RESULTS

After coronary angiography, 10 patients (4%) died during the hospitalization after PPCI. Comparing the non-survivers and discharged patients in terms of arrhythmia predictors showed that the mean QT dispersion and TPE before intervention were significantly higher in the non-survivors. Also, the number of patients who experienced fragmented QRS both before and after the intervention was significantly higher in the non-survivors.

CONCLUSION

These data suggested that evaluating such arrhythmia predictors, especially before PPCI, could be used as a predictor of mortality in STEMI patients who underwent PPCI.

Evaluation of left ventricular diastolic function of patients with coronary heart disease by ultrasound images on bilateral filtering image noise reduction algorithm combined with electrocardiogram

OBJECTIVE

To explore the evaluation of left ventricular diastolic function (LVDF) in patients with coronary heart disease (CHD) using ultrasound images (UI) combined with electrocardiogram (ECG) on bilateral filtering image noise reduction algorithm (BFINRA).

METHODS

A BFINRA was constructed, and 60 subjects who were investigated were divided into a control group (CG) from June 2019 to November 2019 in Taizhou People's Hospital, a myocardial infarction group (MIG), and an angina pectoris group (APG). The patient's LVDF was examined by two-dimensional electrophoresis (2DE) and real-time three-dimensional echocardiography (RT-3DE) combined with ECG. The results showed BFINRA could improve UI quality.

RESULTS

Clinical data indicated there were no substantial differences in age, gender, and fasting blood glucose of all subjects. 2DE examination results showed the left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV), and early diastolic mitral blood flow velocity / early diastolic mitral annulus velocity (E/E') of MIG were much higher than CG (P<0.05), while the left ventricular ejection fraction (LVEF), E / late diastolic mitral blood flow velocity (E/A) and E' peak value were sharply decreased (P<0.05);LVESV and E/E' of APG were increased dramatically (P<0.05), while E peak, E/A and E' peak were decreased greatly. RT-3DE examination results indicated LVEDV and LVESV of MIG were considerably higher than CG (P<0.05), while LVEF and macrophage resistance factor (MRF) were enormously decreased (P<0.05);LVEDV and LVESV of APG were greatly increased (P<0.05). However, LVEF and MRF were not changed significantly (P>0.05). LVEDV had a remarkable difference (P<0.05), but LVESV and LVEF had no obvious differences (P>0.05). The electrocardiogram results illustrated the increase in QT dispersion (QTd) of MIG and APG was statistically significant (P<0.05) compared with CG, while the negative increase of P-wave terminal force in lead V1 (PTFV1) also had a statistical significance (P<0.05). Correlation analysis revealed that MRF and PTFV1 had positive correlation, while MRF and QTd showed a negative correlation.

CONCLUSION

The combination of UI and ECG could better assess LVDF in CHD patients.