A Valuable Tool in Predicting Poor Outcome due to Sepsis in Pediatric Intensive Care Unit: Tp-e/QT Ratio

Early detection of late-onset neonatal sepsis from noninvasive biosignals using deep learning: A multicenter prospective development and validation study

BACKGROUND

Neonatal sepsis is responsible for significant morbidity and mortality worldwide. Its accurate and timely diagnosis is hindered by vague symptoms and the urgent necessity for early antibiotic intervention. The gold standard for diagnosing the condition is the identification of a pathogenic organism from normally sterile sites via laboratory testing. However, this method is resource-intensive and cannot be conducted continuously.

OBJECTIVE

This study aimed to predict the onset of late-onset sepsis (LOS) with good diagnostic value as early as possible using non-invasive biosignal measurements from neonatal intensive care unit (NICU) monitors.

METHODS

In this prospective multicenter study, we developed a multimodal machine learning algorithm based on a convolutional neural network (CNN) structure that uses the power spectral density (PSD) of recorded biosignals to predict the onset of LOS. This approach aimed to discern LOS-related pathogenic spectral signatures without labor-intensive manual artifact removal.

RESULTS

The model achieved an area under the receiver operating characteristic score of 0.810 (95 % CI 0.698-0.922) on the validation dataset. With an optimal operating point, LOS detection had 83 % sensitivity and 73 % specificity. The median early detection was 44 h before clinical suspicion. The results highlighted the additive importance of electrocardiogram and respiratory impedance (RESP) signals in improving predictive accuracy. According to a more detailed analysis, the predictive power arose from the morphology of the electrocardiogram's R-wave and sudden changes in the RESP signal.

CONCLUSION

Raw biosignals from NICU monitors, in conjunction with PSD transformation, as input to the CNN, can provide state-of-the-art prediction performance for LOS without the need for artifact removal. To the knowledge of the authors, this is the first study to highlight the independent and additive predictive potential of electrocardiogram R-wave morphology and concurrent, sudden changes in the RESP waveform in predicting the onset of LOS using non-invasive biosignals.

Predicting Long-Term Ventricular Arrhythmia Risk in Children with Acute Lymphoblastic Leukemia Using Normal Values of Ventricular Repolarization Markers Established from Japanese Cohort Study

BACKGROUND

Cardiac complications due to anthracycline treatment may become evident several years after chemotherapy and are recognized as a serious cause of morbidity and mortality in cancer patients or childhood cancer survivors.

OBJECTIVES

We analyzed ventricular repolarization parameters in electrocardiography for pediatric acute lymphoblastic leukemia patients during chemotherapy and in long-term follow-up. To establish the reference values of ventricular repolarization parameters in children, we retrospectively summarized the Tpe interval, QT interval, QTc interval, and Tpe/QT ratio in healthy Japanese children.

METHODS

Electrocardiography data recorded from students in 1st and 7th grades were randomly selected from a database maintained by the school-based screening system in the Oita city cohort, Japan. Subsequently, chronological data of the Tpe/QT ratio in 17 pediatric patients with acute lymphoblastic leukemia were analyzed over time.

RESULTS

The mean ± standard deviation of the Tpe interval in 1st and 7th graders was 70 ± 7 and 78 ± 17 ms, respectively, while the mean ± standard deviation of the Tpe/QT ratio was 0.21 ± 0.02 and 0.22 ± 0.02 ms, respectively. During the intensive phase of treatment, the Tpe/QT ratios of 3 high-risk patients among the 17 patients with acute lymphoblastic leukemia exceeded the upper limit.

CONCLUSION

The Tpe/QT ratio has a potential clinical application in predicting the risk of long-term ventricular arrhythmia of cancer patients or childhood cancer survivors from childhood to adulthood.

Tp-Te Interval and Tp-Te/QT Ratio Are Valuable Tools in Predicting Poor Outcome in Sepsis Patients

Objective

About 50% of patients with sepsis have different degrees of myocardial inhibition, known as sepsis-induced myocardial dysfunction (SMD), which increases the mortality rate of sepsis. Tp-Te interval and Tp-Te/QT ratio reflect ventricular transmural dispersion repolarization (TDR), and have good predictive value for death in patients with heart disease. This study aimed to investigate the prognostic value of Tp-Te and Tp-Te/QT in patients with sepsis.

Methods

The current study included a total of 625 participants: 201 patients with sepsis, 213 patients with heart failure, and 211 healthy participants. According to the severity and outcome, the patients with sepsis were divided into the sepsis group and the septic shock group, and the death group and the survival group to explore the differences of indicators among subgroups of sepsis. The ROC curve was used to analyze the predictive value of the indicators for deaths of patients with sepsis and calculate the cutoff point. Then, we investigated the incidence of arrhythmia in patients with sepsis with different TDR. The correlation between Tp-Te/QT and the commonly used predictive indicators in ICU was also discussed.

Results

(1) Tp-Te and Tp-Te/QT in patients with sepsis and heart failure (HF) were significantly higher than the control group (p < 0.01). (2) Compared with patients with sepsis, the increase of Tp-Te and Tp-Te/QT is more prominent in patients with HF. Especially, the increase of the Tp-Te/QT was statistically significant (p < 0.001). (3) compared with patients with sepsis (no shock), the Tp-Te, Tp-Te/QT, and SOFA were increased in patients with septic shock (p < 0.05). (4) In the death group, Tp-Te /QT, SOFA, and Apache-II were higher; LVEF was lower than the survival group (p < 0.05). (5) ROC curves showed that Tp-Te/QT, SOFA, and LVEF have predictive values for death (p < 0.05; AUC = 0.808, 0.716, 0.412). The cutoff point of Tp-Te/QT was 0.32. (6) The incidence of arrhythmia is different in patients with sepsis with different TDR. (7) There is a significant correlation between Tp-Te/QT and SOFA (p < 0.001, r = 0.79).

Conclusion

TDR in patients with sepsis is significantly increased, which was between healthy population and patients with HF. Tp-Te and Tp-Te/QT are effective indicators to reflect the severity and poor outcome of patients with sepsis.

Criteria for Pediatric Sepsis-A Systematic Review and Meta-Analysis by the Pediatric Sepsis Definition Taskforce

OBJECTIVE

To determine the associations of demographic, clinical, laboratory, organ dysfunction, and illness severity variable values with: 1) sepsis, severe sepsis, or septic shock in children with infection and 2) multiple organ dysfunction or death in children with sepsis, severe sepsis, or septic shock.

DATA SOURCES

MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched from January 1, 2004, and November 16, 2020.

STUDY SELECTION

Case-control studies, cohort studies, and randomized controlled trials in children greater than or equal to 37-week-old postconception to 18 years with suspected or confirmed infection, which included the terms "sepsis," "septicemia," or "septic shock" in the title or abstract.

DATA EXTRACTION

Study characteristics, patient demographics, clinical signs or interventions, laboratory values, organ dysfunction measures, and illness severity scores were extracted from eligible articles. Random-effects meta-analysis was performed.

DATA SYNTHESIS

One hundred and six studies met eligibility criteria of which 81 were included in the meta-analysis. Sixteen studies (9,629 patients) provided data for the sepsis, severe sepsis, or septic shock outcome and 71 studies (154,674 patients) for the mortality outcome. In children with infection, decreased level of consciousness and higher Pediatric Risk of Mortality scores were associated with sepsis/severe sepsis. In children with sepsis/severe sepsis/septic shock, chronic conditions, oncologic diagnosis, use of vasoactive/inotropic agents, mechanical ventilation, serum lactate, platelet count, fibrinogen, procalcitonin, multi-organ dysfunction syndrome, Pediatric Logistic Organ Dysfunction score, Pediatric Index of Mortality-3, and Pediatric Risk of Mortality score each demonstrated significant and consistent associations with mortality. Pooled mortality rates varied among high-, upper middle-, and lower middle-income countries for patients with sepsis, severe sepsis, and septic shock (p < 0.0001).

CONCLUSIONS

Strong associations of several markers of organ dysfunction with the outcomes of interest among infected and septic children support their inclusion in the data validation phase of the Pediatric Sepsis Definition Taskforce.

Ventricular Repolarization Parameters and Coronary Involvement in Kawasaki Disease

OBJECTIVES

To evaluate electrocardiogram markers to predict coronary involvement in patients with Kawasaki disease by assessing measures of ventricular repolarization parameters on the 12-lead electrocardiogram.

STUDY DESIGN

This cross-sectional study included 180 Spanish and Japanese patients ≤14 years of age with Kawasaki disease, with or without coronary involvement, from 2011 to 2016. We manually measured the Tp-Te/QT ratio and QTc interval (with Bazett's formula) in 12-lead electrocardiogram in the acute and recovery period and explored their potential association with coronary involvement.

RESULTS

No association was found between Tp-Te/QT ratio obtained manually in V5 and V6 leads and coronary involvement in the acute (V5:0.25 [IQR, 0.21-0.27] vs 0.25 [IQR, 0.20-0.27], P = .80; V6:0.24 [IQR, 0.21-0.27] vs 0.25 [IQR, 0.20-0.27], P = .86) or the recovery (V5: 0.23 [IQR, 0.20-0.25] vs 0.23 [IQR, 0.19-0.25], P = .68; V6: 0.23 [IQR, 0.20-0.25] vs 0.23 [IQR, 0.17-0.25], P = .50) period. By contrast, QTc in V5 and V6 was significantly lower in patients with Kawasaki disease and coronary involvement in the acute period (V5: 378 ms [IQR, 364-395 ms] vs 390 ms [IQR, 371-411 ms], P = .04; V6: 377 ms [IQR, 364-392 ms] vs 390 ms [IQR, 371-410 ms], P = .01). A QTc interval of <385 ms in lead V6 was associated with a 2.5-fold increased risk of coronary involvement (OR, 2.5; 95% CI, 1.2-5.3; P = .02).

CONCLUSIONS

Manually measured QTc interval may be a marker of coronary disease in the acute period of Kawasaki disease.

Importance of electrocardiographic markers in predicting cardiac events in children

ECG is a common diagnostic tool in medical practice. Sudden cardiac death (SCD) is a rare but devastating event. The most common cause of SCD in the young is a primary arrhythmic event, which is often produced by malignant ventricular arrhythmia. Several electrocardiographic markers for ventricular repolarization and depolarization have been proposed to predict this arrhythmic risk and SCD in children. Although many of these parameters can easily be used in clinical practice, some of them need specific techniques for interpretation. In this review, we summarized the current knowledge regarding the clinical importance and the ability of these ECG parameters to predict adverse cardiac events in the pediatric population.

Cardiac Arrest Risk During Acute Infections: Systemic Inflammation Directly Prolongs QTc Interval via Cytokine-Mediated Effects on Potassium Channel Expression

BACKGROUND

During acute infections, the risk of malignant ventricular arrhythmias is increased, partly because of a higher propensity to develop QTc prolongation. Although it is generally believed that QTc changes almost exclusively result from concomitant treatment with QT-prolonging antimicrobials, direct effects of inflammatory cytokines on ventricular repolarization are increasingly recognized. We hypothesized that systemic inflammation per se can significantly prolong QTc during acute infections, via cytokine-mediated changes in K⁺ channel expression.

METHODS

We evaluated (1) the frequency of QTc prolongation and its association with inflammatory markers, in patients with different types of acute infections, during active disease and remission; (2) the prevalence of acute infections in a cohort of consecutive patients with Torsades de Pointes; (3) the relationship between K⁺ channel mRNA levels in ventricles and peripheral blood mononuclear cells and their changes in patients with acute infection over time.

RESULTS

In patients with acute infections, regardless of concomitant QT-prolonging antimicrobial treatments, QTc was significantly prolonged but rapidly normalized in parallel to CRP (C-reactive protein) and cytokine level reduction. Consistently in the Torsades de Pointes cohort, concomitant acute infections were highly prevalent (30%), despite only a minority (25%) of these cases were treated with QT-prolonging antimicrobials. KCNJ2 K⁺ channel expression in peripheral blood mononuclear cell, which strongly correlated to that in ventricles, inversely associated to CRP and IL (interleukin)-1 changes in acute infection patients.

CONCLUSIONS

During acute infections, systemic inflammation rapidly induces cytokine-mediated ventricular electrical remodeling and significant QTc prolongation, regardless concomitant antimicrobial therapy. Although transient, these changes may significantly increase the risk of life-threatening ventricular arrhythmia in these patients. It is timely and warranted to transpose these findings to the current coronavirus disease 2019 (COVID-19) pandemic, in which both increased amounts of circulating cytokines and cardiac arrhythmias are demonstrated along with a frequent concomitant treatment with several QT-prolonging drugs. Graphic Abstract: A graphic abstract is available for this article.

The relationship between electrocardiographic data and mortality in children diagnosed with dilated cardiomyopathy

The mortality causes of patients followed up due to dilated cardiomyopathy (DCM) include complications related to heart failure, ventricular arrhythmia, and transplantation. This study aims to evaluate the electrocardiographic findings of patients diagnosed with dilated cardiomyopathy and determine its relationship with mortality. The electrocardiographic, clinical, and laboratory findings of patients diagnosed with dilated cardiomyopathy between January 1, 2012, and September 1, 2018, in our university's pediatric cardiology department were retrospectively evaluated. The electrocardiographic findings of surviving and exitus dilated cardiomyopathy patients were compared and their effect on mortality was investigated. Twelve of the total 85 patients diagnosed with dilated cardiomyopathy were deceased. According to the electrocardiographic findings of surviving and exitus patients, there was a statistically significant difference in terms of P maximum (Pmax), P dispersion (Pdis), QT dispersion (QTdis), QTc maximum (QTcmax), QTc dispersion (QTcdis), Tp-e maximum (Tp-emax), Tp-e dispersion (Tp-edis), and QRS time. Hypertrophy and ischemia findings of electrocardiography were also statistically significant. There was a statistically significant difference between the two groups according to the echocardiographic findings of left ventricular ejection fraction (LVEF), left ventricular shortening fraction (LVSF), left ventricular end-diastolic diameter (LVEDd), and left ventricular end-systolic diameter (LVESd) measurements. It is well known that children diagnosed with dilated cardiomyopathy are at greater risk of arrhythmia compared with normal children. Although previous studies have determined the relationship between mortality and a limited number of electrocardiographic findings, especially in adults, the relationship between electrocardiography findings of children diagnosed with DCM and mortality has not been investigated before in such detail, as in our study.Conclusion: In this study, the significant difference between the electrocardiographic data of deceased and surviving dilated cardiomyopathy patients suggests that electrocardiographic data should be evaluated in detail in order to determine the low and high risk of mortality in patients with dilated cardiomyopathy.What is Known:• Previous studies on the relationship between limited electrocardiography data of adult patients diagnosed with DCM and mortality have been determinedWhat is New:• ECG data has not been investigated in such detail in child DCM patients, as in our study.

The Pattern of Tpeak-Tend Interval and QTdis, and Pdis in Children with Brucellosis

OBJECTIVE

To investigate the effect of inflammation on the conducting system of the heart in patients diagnosed with brucellosis.

METHODS

A total of 42 patients diagnosed with brucellosis and 39 age and sex-matched healthy children were enrolled into the study. Pre- and post-treatment electrocardiographic parameters in brucellosis and control group were recorded from an electrocardiogram for each patient.

RESULTS

The results indicated that the parameters including Pmax, Pdis, QTmax, QTdis, QTcdis, Tp-edis interval and Tp-emax/QTmax and Tp-emax/QTcmax ratios, which are known to be key indicators for the prediction of severe atrial or ventricular arrhythmia and sudden cardiac death and also important parameters used as the indicators for the non-invasive evaluation of the transmural heterogeneity were significantly longer in the study group compared with the control group (p < 0.05).

CONCLUSION

In this study, it was determined that the brucella disease had more cardiac involvement than thought, and this was more in the subclinical form of cardiac involvement.

Systemic Inflammation Rapidly Induces Reversible Atrial Electrical Remodeling: The Role of Interleukin-6-Mediated Changes in Connexin Expression

Background Systemic inflammation is a strong predictor of atrial fibrillation. A key role for electrical remodeling is increasingly recognized, and experimental data suggest that inflammatory cytokines can directly affect connexins resulting in gap-junction dysfunction. We hypothesized that systemic inflammation, regardless of its origin, promotes atrial electric remodeling in vivo, as a result of cytokine-mediated changes in connexin expression. Methods and Results Fifty-four patients with different inflammatory diseases and elevated C-reactive protein were prospectively enrolled, and electrocardiographic P-wave dispersion indices, cytokine levels (interleukin-6, tumor necrosis factor-α, interleukin-1, interleukin-10), and connexin expression (connexin 40, connexin 43) were measured during active disease and after reducing C-reactive protein by >75%. Moreover, peripheral blood mononuclear cells and atrial tissue specimens from an additional sample of 12 patients undergoing cardiac surgery were evaluated for atrial and circulating mRNA levels of connexins. Finally, in vitro effects of interleukin-6 on connexin expression were studied in HL-1 mouse atrial myocytes. In patients with active inflammatory diseases, P-wave dispersion indices were increased but rapidly decreased within days when C-reactive protein normalizes and interleukin-6 levels decline. In inflammatory disease patients, both P-wave dispersion indices and interleukin-6 changes were inversely associated with circulating connexin levels, and a positive correlation between connexin expression in peripheral blood mononuclear cells and atrial tissue was demonstrated. Moreover, interleukin-6 significantly reduced connexin expression in HL-1 cells. Conclusions Our data suggest that regardless of specific etiology and organ localization, systemic inflammation, via interleukin-6 elevation, rapidly induces atrial electrical remodeling by down-regulating cardiac connexins. Although transient, these changes may significantly increase the risk for atrial fibrillation and related complications during active inflammatory processes.

Role of complement C5a and histones in septic cardiomyopathy

Polymicrobial sepsis (after cecal ligation and puncture, CLP) causes robust complement activation with release of C5a. Many adverse events develop thereafter and will be discussed in this review article. Activation of complement system results in generation of C5a which interacts with its receptors (C5aR1, C5aR2). This leads to a series of harmful events, some of which are connected to the cardiomyopathy of sepsis, resulting in defective action potentials in cardiomyocytes (CMs), activation of the NLRP3 inflammasome in CMs and the appearance of extracellular histones, likely arising from activated neutrophils which form neutrophil extracellular traps (NETs). These events are associated with activation of mitogen-activated protein kinases (MAPKs) in CMs. The ensuing release of histones results in defective action potentials in CMs and reduced levels of [Ca²⁺]i-regulatory enzymes including sarco/endoplasmic reticulum Ca²⁺-ATPase (SERCA2) and Na⁺/Ca²⁺ exchanger (NCX) as well as Na⁺/K⁺-ATPase in CMs. There is also evidence that CLP causes release of IL-1β via activation of the NLRP3 inflammasome in CMs of septic hearts or in CMs incubated in vitro with C5a. Many of these events occur after in vivo or in vitro contact of CMs with histones. Together, these data emphasize the role of complement (C5a) and C5a receptors (C5aR1, C5aR2), as well as extracellular histones in events that lead to cardiac dysfunction of sepsis (septic cardiomyopathy).

The effect of type 2 diabetes on electrocardiographic markers of significant cardiac events

Background & Objectives:

In diabetics, cardiac microvascular circulation disorder increases the risk of arrhythmia and sudden cardiac death. Tpeak-Tend (Tp-e) interval, Tp-e dispersion, and Tp-e/QT and Tp-e/QTc ratios measured by surface electrocardiogram (ECG) are new parameters used to evaluate ventricular arrhythmogenity. We aimed to compare QT dispersion (QTd), corrected QT dispersion (QTcd), P dispersion (Pd), Tp-e interval, Tp-e dispersion, and Tp-e/QT and Tp-e/QTc ratios in patients with type- 2 diabetes (T2D) with healthy population.

Methods:

Electrocardiographic parameters of a total of 100 patients diagnosed with T2D were retrospectively analyzed and compared with the ECG results of 100 healthy age-, sex-, and body weight and height-matched controls.

Results:

The Pd, QT interval, QTc interval, QTd, QTcd, Tp-e/QT, Tp-e/QT ratios were higher in the patients. A statistically significant correlation was found only between hemoglobin A1c and Tp-e dispersion, QTd, QTcd, Pd, Tp-e/QT and Tp-e/QTc parameters, in linear regression analysis. There was also a statistically significant positive correlation between the values of low-density lipoprotein, systolic blood pressure, and Tp-e dispersion.

Conclusion:

The risk of arrhythmia can be predicted by evaluating Tp-e interval, Tp-e dispersion, Tp-e/QT, and Tp-e/QTc ratio, suggesting heterogeneity of ventricular repolarization and P wave and Pd showing heterogeneity of atrial repolarization in diabetic patients.

Meta-analysis of Tpeak-Tend and Tpeak-Tend/QT ratio for risk stratification in congenital long QT syndrome

BACKGROUND AND OBJECTIVES

Congenital long QT syndrome (LQTS) predisposes affected individuals to ventricular tachycardia/fibrillation (VF/VF), potentially resulting in sudden cardiac death. The T_peak-T_end interval and the T_peak-T_end/QT ratio, electrocardiographic markers of dispersion of ventricular repolarization, were proposed for risk stratification but their predictive values in LQTS have been controversial. A systematic review and meta-analysis was conducted to examine the value of T_peak-T_end intervals and T_peak-T_end/QT ratios in predicting arrhythmic and mortality outcomes in congenital LQTS.

METHOD

PubMed and Embase databases were searched until 9th May 2017, identifying 199 studies.

RESULTS

Five studies on long QT syndrome were included in the final meta-analysis. T_peak-T_end intervals were longer (mean difference [MD]: 13ms, standard error [SE]: 4ms, P=0.002; I²=34%) in congenital LQTS patients with adverse events [syncope, ventricular arrhythmias or sudden cardiac death] compared to LQTS patients without such events. By contrast, T_peak-T_end/QT ratios were not significantly different between the two groups (MD: 0.02, SE: 0.02, P=0.26; I²=0%).

CONCLUSION

This meta-analysis showed that T_peak-T_end interval is significant higher in individuals who are at elevated risk of adverse events in congenital LQTS, offering incremental value for risk stratification.