Relationship between QT interval dispersion in acute stroke and stroke prognosis: a systematic review

The Impact of QT-Prolonging Medications and Drug-Drug Interactions on QTc Interval Prolongation in Hospitalized Patients: A Case-Crossover Study

Researchers have studied potential corrected QT interval (QTc) prolongation from drug-drug interactions (DDIs), raising unresolved questions about their real-world impact. This retrospective case-crossover study investigated the effects of QT-prolonging drugs and DDIs on QTc prolongation in hospitalized patients aged 45 years and above. The cohort comprised patients who had multiple hospitalizations and developed QTc prolongation (QTc > 500 ms or an increase of >60 ms from baseline) at least 24 hours after admission between 2011 and 2019. Conditional logistic regression compared drug exposure between hospitalizations with QTc prolongation (case window) and those without (reference window). Among 2,276 patients (mean age 71; 43.8% female), the use of QT-prolonging drugs significantly increased the risk of QTc prolongation (odds ratio: 2.42 (95% confidence interval: 1.95-3.02)). The risk was higher with drugs of "known risks" (OR: 3.78 (2.91-4.90)) and "conditional risk" (OR: 2.08 (1.65-2.62)). DDIs, particularly involving multiple "known risk" drugs (OR: 7.86 (4.96-12.45)), strong cytochrome P450 enzyme inhibitors (OR: 5.57 (2.75-11.30)), or the concurrent use of ≥4 QT-prolonging drugs with any risk (OR: 5.28 (3.96-7.03)) substantially increased the risk. Cautious prescribing for patients with multiple risk factors is important to minimize the likelihood of QTc prolongation. However, when considering enhanced monitoring or drug choices, it is crucial to carefully evaluate the overall risk of QT prolongation against the benefits of treatment to ensure optimal patient care.

The insular cortex, autonomic asymmetry and cardiovascular control: looking at the right side of stroke

PURPOSE

Evidence from animal and human studies demonstrates that cortical regions play a key role in autonomic modulation with a differential role for some brain regions located in the left and right brain hemispheres. Known as autonomic asymmetry, this phenomenon has been demonstrated by clinical observations, by experimental models, and currently by combined neuroimaging and direct recordings of sympathetic nerve activity. Previous studies report peculiar autonomic-mediated cardiovascular alterations following unilateral damage to the left or right insula, a multifunctional key cortical region involved in emotional processing linked to autonomic cardiovascular control and featuring asymmetric characteristics.

METHODS

Based on clinical studies reporting specific damage to the insular cortex, this review aims to provide an overview of the prognostic significance of unilateral (left or right hemisphere) post-insular stroke cardiac alterations. In addition, we review experimental data aiming to unravel the central mechanisms involved in post-insular stroke cardiovascular complications.

RESULTS AND CONCLUSION

Current clinical and experimental data suggest that stroke of the right insula  can present a worse cardiovascular prognosis.

Electrocardiogram alterations in non-traumatic brain injury: a systematic review

The presence of abnormal electrocardiograms in individuals without known organic heart disease is one of the most common manifestations of cardiac dysfunction occurring during acute non traumatic brain injury. The primary goal of the present review is to provide an overview of the available data and literature regarding the presence of new-onset electrocardiographic (ECG) alterations in acute non traumatic brain injury. The secondary aim is to identify the incidence of ECG alterations and consider the prognostic significance of new-onset ECG changes in this setting. To do so, English language articles from January 2000 to January 2022 were included from PubMed using the following keywords: "electrocardiogram and subarachnoid hemorrhage", "electrocardiogram and intracranial hemorrhage", "Q-T interval and subarachnoid hemorrhage ", "Q-T interval and intracranial bleeding ", "Q-T interval and intracranial hemorrhage", and "brain and heart- interaction in stroke". Of 3162 papers, 27 original trials looking at electrocardiogram alterations in acute brain injury were included following the PRISMA guideline. ECG abnormalities associated with acute brain injury could potentially predict poor patient outcomes. They could even herald the future development of neurogenic pulmonary edema (NPE), delayed cerebral ischemia (DCI), and even in-hospital death. In particular, patients with SAH are at increased risk of having severe ventricular dysrhythmias. These may contribute to a high mortality rate and to poor functional outcome at 3 months. The current data on ECG QT dispersion and mortality appear less clearly associated. While some patients demonstrated poor outcomes, others showed no relationship with poor outcomes or increased in-hospital mortality. Observing ECG alterations carefully after cerebral damage is important in the critical care of these patients as it can expose preexisting myocardial disease and change prognosis.

Relationship between Alzheimer dementia and QT interval: A meta-analysis

While the link between aging and mortality from dementia is widely appreciated, the mechanism is not clear. The objective of this study was to determine whether there is a direct relationship between Alzheimer dementia (AD) and the QT interval, because the latter has been related to cardiac mortality. A systematic review and meta-analysis were conducted after a Medline and EMBASE search using terms "Alzheimer disease or Dementia AND QT interval, QT dispersion or cardiac repolarization." Four studies with control groups were identified. There were significant differences in QT interval between individuals with AD vs individuals without dementia (controls) (odds ratio (OR)1.665 [random effects model] and 1.879 [fixed effect model]) (p < 0.001). There were significant differences in QT interval between individuals with AD vs individuals with mild cognitive impairment (MCI) (OR 1.760 [random effects] and 1.810 [fixed effect]) (p < 0.001). A significant (p <0.001) correlation exists between the QTc and the Mini-Mental State Exam (MMSE), a test of cognitive function. Two studies examined QT variability (the difference between the longest and shortest QT interval on a 12 lead ECG); the OR for QT variability AD vs MCI was 3.858 [random effects model] and 3.712 [fixed effects model] (p < 0.001). When compared to the control group, the OR for QT dispersion in AD was 6.358 [random effects model] or 5.143 ( P< 0.001) [fixed effects model]. A qualitative analysis of the data raised questions about paucity of data defining the nature of the control groups, the pathophysiologic mechanism, and the uniform use of a poor QT heart rate correction factor. The longer QT in AD, greater QT variability in AD, and the direct relationship between QT interval and AD severity supports a brain-heart connection in AD that might be fundamental to aging-induced AD and mortality. Issues with defining the control group, limited number of studies, conflicting data in population studies, and the lack of a strong electrophysiological basis underscore the need for additional research in this field.

QT Interval Dispersion as a Predictor of Clinical Outcome in Acute Ischemic Stroke

Background and Purpose: QT dispersion (QTd) abnormalities are widely documented in stroke patients. This study aims to investigate the association between QTd and clinical outcomes in IS patients.

Methods: IS patients registered in the Blood Pressure and Clinical Outcome in transient ischemic attack (TIA) or IS (BOSS) registry between 2012 and 2014 within 24 h of onset were analyzed. In this prospective observational study, we identified 1,522 IS cases with adequate electrocardiographic evaluations to assess QTd after the index stroke. Patients were classified into four groups based on the quartile of QTd, with the lowest group as the reference. The primary stroke outcome was defined as a modified Rankin Scale score ≥3 at 1-year. Multiple logistic regressions were utilized to investigate the association between QTd and outcome events.

Results: The mean QTd across all cases was 57 ms (40–83). Functional dependency or death was documented in 214 (14.98%) cases at 1 year. After adjusting for confounders, the prevalence of death and major disability (mRS ≥ 3) showed significant differences according to the quartile of QTd, with the risk of death and major disability (mRS ≥ 3) at 1 year being significantly higher for patients in Q4 than for those in Q1 (adjusted OR = 1.626, 95% CI:1.033–2.560). However, there were no significant correlation between QTd and the event outcomes at 1 year.

Conclusions: QTd was associated with poor functional outcomes at 1 year. QTd is a useful surrogate marker for adverse functional prognosis, which might help to stratify risk in patients with acute IS.

Electrocardiographic changes following intracranial haemorrhage: a retrospective cohort study

OBJECTIVE

To improve the understanding of the association between electrocardiographic (ECG) abnormalities and clinical outcomes of patients with all types of intracranial hemorrhage (ICH).

METHODS

A retrospective cohort study was conducted in a tertiary healthcare hospital on patients with ICH without cardiac disease or renal disease requiring dialysis. Demographic and clinical data were collected from hospital records. ECG record were obtained within 24 hours of presentation and prior to treatment. Records were interpreted for this study by a cardiologist blinded to other data.

RESULTS

Assessment of 291 patients (228 adults and 63 children) showed that subdural hemorrhage was the most common type of ICH (31.6%) followed by intraparenchymal hemorrhage (23.0%). ECG records were available for 98 patients. ECG abnormalities were most commonly nonspecific ST-segment changes (32.6%). In adults, history of neurological disease was associated with atrioventricular block (p=.004) and QTc prolongation (p=.041). Pediatric patients exhibited associations between ST-segment changes (p=.045) and sinus tachycardia (p=.027) and type of ICH. However, ECG changes were not statistically associated with clinical outcomes in adults or children.

CONCLUSION

Significant ECG changes frequently occurred in patients with all types of ICH but did not consistently predict the outcome in this study. Close observation of patients is still recommended to detect ECG changes that could affect the treatment.

Electrocardiographic changes after high-dose corticosteroid pulse therapy in pemphigus patients

PURPOSE

The objective of the current study was to evaluate the effect of intravenous methylprednisolone pulse therapy on myocardial repolarization alterations, especially QT dispersion in anticipation of cardiovascular risks in patients with pemphigus vulgaris.

METHODS

The current study is a prospective-controlled study on the electrocardiographic changes after methylprednisolone pulse therapy in 50 patients with pemphigus vulgaris.

RESULTS

A total of 50 patients (28 female and 22 male) were included in our study. The mean heart rate was significantly higher in male patients both before (92 ± 10.80 versus 82.75 ± 12.01 ms) and after pulse therapy (102.73 ± 14.26 versus 91.07 ± 15.02 ms) (p value < .01). The value of heart rate was significantly greater after receiving steroid pulse therapy. Corrected QT dispersion before pulse therapy was 19.92 ± 8.2 ms that increased to 40.68 ± 18.12 ms after treatment (p value < .001).

CONCLUSION

Our study shows that there is a relationship between pulse steroid infusion and increased predisposition to the occurrence of cardiac arrhythmias. QT dispersion could be a good marker to assess this risk in these patients.

Heart-brain Interactions in Heart Failure

Heart failure (HF) is a complex disease with a growing incidence worldwide. HF is accompanied by a wide range of conditions which affect disease progression, functional performance and contribute to growing healthcare costs. The interactions between a failing myocardium and altered cerebral functions contribute to the symptoms experienced by patients with HF, affecting many comorbidities and causing a poor prognosis. This article provides a condensed version of the 2018 position paper from the Study Group on Heart and Brain Interaction of the Heart Failure Association. It addresses the reciprocal impact on HF of several pathological brain conditions, including acute and chronic low perfusion of the brain, and impairment of higher cortical and brain stem functions. Treatment-related interactions - medical, interventional and device-related - are also discussed.

Dynamic changes of QTc interval and prognostic significance in takotsubo (stress) cardiomyopathy

BACKGROUND

Prolonged QT corrected (QTc) intervals are associated with adverse cardiovascular outcomes both in healthy and high-risk populations. Our objective was to evaluate the QTc intervals during a takotsubo cardiomyopathy (TTC) episodes and their potential prognostic role.

HYPOTHESIS

Dynamic changes of QTc interval during hospitalization for TTC could be associated with outcome at follow-up.

METHODS

Fifty-two consecutive patients hospitalized for TTC were enrolled. Twelve-lead electrocardiogram (ECG) was performed within 3 h after admission and repeated after 3, 5, and 7 days. Patients were classified in 2 groups: group 1 presented the maximal QTc interval length at admission and group 2 developed maximal QTc interval length after admission.

RESULTS

Mean admission QTc interval was 493 ± 71 ms and mean QTc peak interval was 550 ± 76 ms (P < 0.001). Seventeen (33%) patients were included in group 1 and 35 (67%) patients in group 2. There were no differences for cardiovascular risk factors and in terms of ECG findings such as ST elevation, ST depression, and inverted T waves. Rates of adverse events during hospitalization among patients of group 1 and 2 were different although not significantly (20% vs 6%, P = 0.22). After 647 days follow-up, patients of group 1 presented higher risk of cardiovascular rehospitalization (31% vs 6%, P = 0.013; log-rank, P < 0.01). At multivariate analysis, including age and gender, a prolonged QTc interval at admission was significantly associated with higher risk of rehospitalization at follow-up (hazard ratio: 1.07 every 10 ms, 95% confidence interval: 1.003-1.14, P = 0.04).

CONCLUSIONS

Prolonged QTc intervals at admission during a TTC episode could be associated with a higher risk of cardiovascular rehospitalization at follow-up. Dynamic increase of QTc intervals after admission are characterized by a trend toward a better prognosis.

Increased QT dispersion is associated with reduced overall survival in patients with acute exacerbations of chronic obstructive pulmonary disease

OBJECTIVES

Chronic obstructive pulmonary disease (COPD), especially acute exacerbations of COPD, are associated with increased cardiovascular mortality, including sudden cardiac death. Previous studies have reported that ECG abnormalities are common in stable COPD patients. However, the prognostic utility of ECG taken at the time of AECOPD is not known. In this study we sought to address this gap in knowledge pertaining to ECG parameters at time of AECOPD and overall survival.

METHODS

We conducted a retrospective cohort study of patients admitted to our institution with a primary diagnosis of AECOPD. Standard 12-lead ECG obtained at the time of initial presentation was evaluated. The primary outcome was overall survival.

RESULTS

Two hundred and eleven AECOPD patients were considered for the study. Death had occurred in 42 (20%) patients at follow-up. Among the different ECG parameters evaluated, the QT Dispersion (QTD) and corrected QT Dispersion (QTcD) were significantly associated with increased mortality. Receiver Operator Characteristic analysis identified QTcD >48msec had a sensitivity of 90% and specificity of 55% in predicting death and QTcD >48msec was also associated with worse overall survival (months) (mean ± SD: 26 ± 1.0 vs. 30 ± 0.7, p = 0.001).

CONCLUSION

QTcD ≥48msec is associated with increased mortality. Further research is required to better understand this association and potentially identify reversible factors that if appropriately addressed, may ultimately improve the prognosis of patients with COPD.

Reduced functional connectivity between ventromedial prefrontal cortex and insula relates to longer corrected QT interval in HIV+ and HIV- individuals

OBJECTIVE

Prolongation of the QT interval, i.e., measure of the time between the start of the Q wave and the end of the T wave, is a precursor to fatal cardiac arrhythmias commonly observed in individuals infected with the Human Immunodeficiency Virus (HIV), and is related to dysregulation of the autonomic nervous system. We investigated the relationship between QT interval length and resting state functional connectivity (rsFC) of the ventromedial prefrontal cortex (VMPFC), a core region of the brain that is involved with cardio-autonomic regulation.

METHOD

Eighteen HIV+ men on antiretroviral therapy and with no history of heart disease were compared with 26 HIV-negative control subjects who had similar demographic and cardio-metabolic characteristics. A seed-based rsFC analysis of the right and left VMPFC was performed at the individual subject level, and 2nd-level analyses were conducted to identify the following: group differences in connectivity, brain regions correlating with corrected (QTc) interval length before and after controlling for those group differences, and regions where seed-based rsFC correlates with CD4 count and QTc interval within HIV+ individuals.

RESULTS

HIV-negative adults showed greater rsFC between the VMPFC seed regions and several default mode network structures. Across groups greater rsFC with the left anterior insula was associated with shorter QTc intervals, whereas right posterior insula connectivity with the VMPFC correlated with greater QTc intervals. HIV patients with lower CD4 counts and higher QTc intervals showed greater rsFC between the right VMPFC and the right posterior insula and dorsal cingulate gyrus.

CONCLUSIONS

This study demonstrates that QTc interval lengths are associated with distinct patterns of VMPFC rsFC with posterior and anterior insula. In HIV patients, longer QTc interval and lower CD4 count corresponded to weaker VMPFC connectivity with the dorsal striatrum.

SIGNIFICANCE

A forebrain control mechanism may be implicated in the suppression of cardiovagal influence that confers risk for ventricular arrhythmias and sudden cardiac death in HIV+ individuals.

The evaluation of a new marker of transmyocardial repolarization parameters in ischemic stroke patients; T peak-T end (T p-e), T p-e/QTc

The cardiovascular manifestations of acute ischemic stroke have been well known. Several electrocardiography (ECG) abnormalities have been reported in patients following acute stroke, including QT interval prolongation, ST segment deviation and T-wave changes. This study aimed to investigate the changes in transmyocardial repolarization parameters, in ischemic stroke patients. The study is a prospective, blind, and controlled clinical study. The patients without cardiac disease who received ischemic stroke diagnoses were included in the study. ECG was received from the patients in the first hour and 72 h. The P, QT, T _p-e, T _p-e dispersion, and the T _p-e/QT ratio were calculated. Moreover, fifty-five stroke patients and 35 control subjects were included to the study. All dispersion values and T _p-e/QT_c ratio in patients group were higher than those of control group (p < 0.05 for all values). When evaluated between ECGs' on first and third days, it was found that decreasing on all dispersion values and T _p-e/QT_c ratio in ECGs on third day than ECGs on first day (p < 0.05 for all values). QT, QT_c, and T _p-e dispersions values in patients who have insular lobe involvement were higher than those of patients who do not have insular lobe involvement (p < 0.001 for all values). In this study, we showed that acute stroke increases that P _d, QT_d, QT_cd and new repolarization markers T _p-e and T _p-e/QT_c, during first 24 and 72 h in acute stroke patients without cardiovascular disease compared with the control group. The physicians should be aware about ventricular dysrhythmias in patients with ischemic stroke and these patients closely observed with cardiac monitoring, especially within first 24 h, and especially patients with insular lobe involvement.

Computational Electrocardiography: Revisiting Holter ECG Monitoring

BACKGROUND

Since 1942, when Goldberger introduced the 12-lead electrocardiography (ECG), this diagnostic method has not been changed.

OBJECTIVES

After 70 years of technologic developments, we revisit Holter ECG from recording to understanding.

METHODS

A fundamental change is fore-seen towards "computational ECG" (CECG), where continuous monitoring is producing big data volumes that are impossible to be inspected conventionally but require efficient computational methods. We draw parallels between CECG and computational biology, in particular with respect to computed tomography, computed radiology, and computed photography. From that, we identify technology and methodology needed for CECG.

RESULTS

Real-time transfer of raw data into meaningful parameters that are tracked over time will allow prediction of serious events, such as sudden cardiac death. Evolved from Holter's technology, portable smartphones with Bluetooth-connected textile-embedded sensors will capture noisy raw data (recording), process meaningful parameters over time (analysis), and transfer them to cloud services for sharing (handling), predicting serious events, and alarming (understanding). To make this happen, the following fields need more research: i) signal processing, ii) cycle decomposition; iii) cycle normalization, iv) cycle modeling, v) clinical parameter computation, vi) physiological modeling, and vii) event prediction.

CONCLUSIONS

We shall start immediately developing methodology for CECG analysis and understanding.

Evaluation of ventricular repolarization in pregnant women with intrahepatic cholestasis

BACKGROUND

Bile acids can induce arrhythmia by altering cardiomyocyte contractility or electrical conduction. The aim of this study was to investigate, by means of QT dispersion parameter detected by simple standard electrocardiogram (ECG), ventricular repolarization changes in pregnant women with and without intrahepatic cholestasis of pregnancy (ICP).

METHODS

In this case-control study including 75 pregnant women with cholestasis and 35 healthy, uncomplicated pregnancy cases, electrocardiographic QT interval durations and QT dispersion (QT-disp) parameters, corrected for the patients' heart rate using the Hodges formula, were investigated.

RESULTS

Maximum corrected QT interval values were significantly higher in the severe ICP group than in the control group (p < 0.001) and significantly higher in the severe ICP group than in the mild ICP group (p = 0.01). The values of the mild ICP and control groups were similar. Corrected QT-disp values were also significantly higher in both ICP groups than in the control group and significantly higher in the severe ICP group than in the mild ICP group.

CONCLUSION

Cholestatic diseases predispose patients to cardiovascular complications. Our data clearly demonstrated that QT-disp values were significantly altered in pregnant women with cholestasis when compared to the normal ones. This simple ECG parameter can be used to screen high-risk women, in order to better target counseling regarding lifestyle modifications and to conduct closer follow up and management of women with a history of ICP.