[QT interval and acute myocardial ischemia: past promises, new evidences]

Factors Associated With Electrocardiographic Abnormalities in Patients With Sickle Cell Disease: A Systematic Review and Meta-Analysis

INTRODUCTION

Sickle cell disease (SCD) is frequently associated with cardiovascular complications, with cardiac involvement being evident in the electrocardiogram (ECG). This study aimed to systematically research the literature to investigate factors associated with ECG abnormalities in SCD patients.

METHOD

Five online databases of PubMed, Scopus, Web of Science, Embase, and Google Scholar were reviewed using a broad search strategy to identify original studies reporting factors associated with abnormal ECG findings among patients with SCD. Using Comprehensive Meta-Analysis software, various effect sizes-odds ratios (ORs), mean differences, and correlation coefficients-were analyzed, pooled with a random effects model, and visualized through forest plots.

RESULTS

Data analysis from 23 studies covering 2943 SCD patients revealed increased odds of prolonged QTc interval (2.54, 95% CI = 1.34-4.83), ST segment elevation (9.23, 95% CI = 3.15-27.07), and ST segment depression (3.82, 95% CI = 1.99-7.33) during crises. Patients with moderate SCD severity had higher odds of having any ECG abnormalities compared to those with mild severity (2.80, 95% CI = 1.47-5.33). No significant associations were observed between moderate and mild severity for left ventricular hypertrophy, sinus arrhythmia, and sinus tachycardia, or between male and female for having any ECG abnormalities, left ventricular hypertrophy, and prolonged QTc interval. Additionally, mean hemoglobin level was 0.60 mg/dL lower (95% CI = -0.91 to 0.28) in those with prolonged QTc interval.

CONCLUSION

This study highlights the link between SCD status and severity, and hemoglobin, and ECG abnormalities. It emphasizes the need for cardiac monitoring, caution with QTc-prolonging medications, and routine ECG assessments to prevent cardiovascular complications in these high-risk patients.

A new electrocardiographic parameter terminal D1S + D3R predicts right ventricular dilatation in acute pulmonary embolism

OBJECTIVE

Right ventricular (RV) overload findings affect the risk classification and treatment approach in acute pulmonary embolism (APE). Recently, it was reported that a new electrocardiography (ECG) parameter, terminal D1S + D3R (T-D1S + D3R) pattern, supported the diagnosis of APE. We aim to search the relationship between T-D1S + D3R pattern and right ventricular dilatation (RVD) in APE.

METHODS

This single-centre, retrospective study was designed with patients aged > 18 years. We screened 267 patients who underwent transthoracic echocardiography (TTE) because of confirmed APE in our emergency department. This study included 72 patients with RVD and 139 patients without RVD [male 41.7%, median age 73,0 (20.8) years; 49.6% male, median age 64,0 (24.0) years]. We compared T-D1S + D3R between RVD (+) and RVD (-) groups.

RESULTS

We determined that RVD (+) group had more patients with the T-D1S + D3R parameter than RVD (-) group [51 (70.8%) vs. 25 (18.0%), p < 0.001]. In the univariate logistic regression analyses S1Q3T3, (in)complete right bundle branch block (RBBB), T-D1S + D3R, D3-V1 T wave inversion (TWI), V1-3/4 TWI, V1-3/4 ST-segment elevation, and frontal QRS-T [f(QRS-T)] angle predicted RVD, while T-D1S + D3R, V1-3/4 ST-segment elevation, and f(QRS-T) angle remained independent predictors of RVD in patients with APE.

CONCLUSIONS

T-D1S + D3R, a new ECG parameter, was an independent predictor of RVD in patients with APE.

Electrocardiographic abnormalities in patients with sickle cell disease: A systematic review and meta-analysis

BACKGROUND

Previous studies have documented that electrocardiography (ECG) can reveal a range of abnormalities, offering valuable insights into the cardiac evaluation of patients with sickle cell disease (SCD). The objective of this study is to assess the patterns of ECG abnormalities observed in these patients with SCD, and to determine their prevalence.

METHOD

We systematically reviewed the literature using online databases of PubMed, Scopus, Web of Science, Embase, and Google Scholar to identify original studies that reported findings of standard ECG assessments in patients with SCD. Statistical analyses were performed using the random effects model. Additional analyses including sensitivity analysis and subgroup analysis were also conducted.

RESULTS

Analysis of data from 59 studies involving 897,920 individuals with SCD revealed that 75% of these patients had abnormal ECG findings (67%-81%), which were predominantly nonspecific ST-T changes, left ventricular hypertrophy, T-wave changes, prolonged corrected QT (QTc) interval, and ischemic changes. Besides, it was shown that these patients had significantly higher odds of having any ECG abnormalities (OR of 17.50, 4.68-65.49), right atrial enlargement (6.09, 1.48-25.09), left ventricular hypertrophy (3.45, 1.73-6.89), right ventricular hypertrophy (7.18, 2.28-22.57), biventricular hypertrophy (10.11, 1.99-51.38), prolonged QTc interval (5.54, 2.44-12.59), ST depression (3.34, 1.87-5.97), and T-wave changes (5.41, 1.43-20.56). Moreover, the mean of QTc interval was significantly higher among those with SCD (23.51 milliseconds, 16.08-30.94).

CONCLUSION

Our meta-analysis showed a higher prevalence of abnormal ECG findings among individuals with SCD. A significant proportion of these patients had various ECG abnormalities, suggesting a potential need for regular ECG assessments for patients with SCD.

Delayed cardiac repolarisation as a predictor of in-hospital mortality in patients with COVID-19

OBJECTIVE

With the rapid influx of COVID-19 admissions during the first wave of the pandemic, there was an obvious need for an efficient and streamlined risk stratification tool to aid in triaging. To this date, no clinical prediction tool exists for patients presenting to the hospital with COVID-19 infection.

METHODS

This is a retrospective cohort study of patients admitted in one of 13 Northwell Health Hospitals, located in the wider New York Metropolitan area between 1 March 2020 and 27 April 2020. Inclusion criteria were a positive SARS-CoV-2 nasal swab, a 12-lead ECG within 48 hours, and a complete basic metabolic panel within 96 hours of presentation.

RESULTS

All-cause, in-hospital mortality was 27.1% among 7098 patients. Independent predictors of mortality included demographic characteristics (male gender, race and increased age), presenting vitals (oxygen saturation <92% and heart rate >120 bpm), metabolic panel values (serum lactate >2.0 mmol/L, sodium >145, mmol/L, blood urea nitrogen >40 mmol/L, aspartate aminotransferase >40 U/L, Creatinine >1.3 mg/dL and glycose >100 mg/L) and comorbidities (congestive heart failure, chronic obstructive pulmonary disease and coronary artery disease). In addition to those, our analysis showed that delayed cardiac repolarisation (QT corrected for heart rate (QTc) >500 ms) was independently associated with mortality (OR 1.41, 95% CI 1.05 to 1.90). Previously mentioned parameters were incorporated into a risk score that accurately predicted in-hospital mortality (AUC 0.78).

CONCLUSION

In the largest cohort of COVID-19 patients with complete ECG data on presentation, we found that in addition to demographics, presenting vitals, clinical history and basic metabolic panel values, QTc >500 ms is an independent risk factor for in-hospital mortality.

Incremental value of QT interval for the prediction of obstructive coronary artery disease in patients with chest pain

Identification of obstructive coronary artery disease (OCAD) in patients with chest pain is a clinical challenge. The value of corrected QT interval (QTc) for the prediction of OCAD has yet to be established. We consecutively enrolled 1741 patients with suspected angina. The presence of obstructive OCAD was defined as ≥ 50% diameter stenosis by coronary angiography. The pre-test probability was evaluated by combining QTc prolongation with the CAD Consortium clinical score (CAD2) and the updated Diamond-Forrester (UDF) score. OCAD was detected in 661 patients (38.0%). QTc was longer in patients with OCAD compared with those without OCAD (444 ± 34 vs. 429 ± 28 ms, p < 0.001). QTc was increased by the severity of OCAD (P < 0.001). QTc prolongation was associated with OCAD (odds ratio (OR), 2.27; 95% confidence interval (CI), 1.81–2.85). With QTc, the C-statistics increased significantly from 0.68 (95% CI 0.66–0.71) to 0.76 (95% CI 0.74–0.78) in the CAD2 and from 0.64 (95% CI 0.62–0.67) to 0.74 (95% CI 0.72–0.77) in the UDF score, respectively. QT prolongation predicted the presence of OCAD and the QTc improved model performance to predict OCAD compared with CAD2 or UDF scores in patients with suspected angina.

Regadenoson administration and QT interval prolongation during pharmacological radionuclide myocardial perfusion imaging

The objective of our study is to assess change in QTc interval with Regadenoson administration during myocardial perfusion imaging (MPI). We conducted a retrospective, observational analysis of 1497 consecutive patients who underwent pharmacological radionuclide MPI. On multivariate logistic regression analyses, there was no statistical significance of QTc prolongation when adjusted for ischemia/fixed perfusion defect on MPI and QT prolonging medications being taken prior to stress testing. However, a positive stress ECG after Regadenoson injection had a statistical significance (p value 0.0004). Regadenoson is a safe drug for use in MPI with little, if any, side effects of major clinical significance.

In-Hospital Prognostic Value of Electrocardiographic Parameters Other Than ST-Segment Changes in Acute Myocardial Infarction: Literature Review and Future Perspectives

Electrocardiography (ECG) remains an irreplaceable tool in the management of the patients with myocardial infarction, with evaluation of the QRS and ST segment being the present major focus. Several ECG parameters have already been proposed to have prognostic value with regard to both in-hospital and long-term follow-up of patients. In this review, we discuss various ECG parameters other than ST segment changes, particularly with regard to their in-hospital prognostic importance. Our review not only evaluates the prognostic segments and parts of ECG, but also highlights the need for an integrative approach in big data to re-assess the parameters reported to predict in-hospital prognosis. The evolving importance of artificial intelligence in evaluation of ECG, particularly with regard to predicting prognosis, and the potential integration with other patient characteristics to predict prognosis, are discussed.

Intracellular ATP binding is required to activate the slowly activating K+ channel I(Ks)

Gating of ion channels by ligands is fundamental to cellular function, and ATP serves as both an energy source and a signaling molecule that modulates ion channel and transporter functions. The slowly activating K(+) channel I(Ks) in cardiac myocytes is formed by KCNQ1 and KCNE1 subunits that conduct K(+) to repolarize the action potential. Here we show that intracellular ATP activates heterologously coexpressed KCNQ1 and KCNE1 as well as I(Ks) in cardiac myocytes by directly binding to the C terminus of KCNQ1 to allow the pore to open. The channel is most sensitive to ATP near its physiological concentration, and lowering ATP concentration in cardiac myocytes results in I(Ks) reduction and action potential prolongation. Multiple mutations that suppress I(Ks) by decreasing the ATP sensitivity of the channel are associated with the long QT (interval between the Q and T waves in electrocardiogram) syndrome that predisposes afflicted individuals to cardiac arrhythmia and sudden death. A cluster of basic and aromatic residues that may form a unique ATP binding site are identified; ATP activation of the wild-type channel and the effects of the mutations on ATP sensitivity are consistent with an allosteric mechanism. These results demonstrate the activation of an ion channel by intracellular ATP binding, and ATP-dependent gating allows I(Ks) to couple myocyte energy state to its electrophysiology in physiologic and pathologic conditions.