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.

Neural coding of autonomic functions in different states of consciousness

Detecting signs of residual neural activity in patients with altered states of consciousness is a crucial issue for the customization of neurorehabilitation treatments and clinical decision-making. With this large observational prospective study, we propose an innovative approach to detect residual signs of consciousness via the assessment of the amount of autonomic information coded within the brain. The latter was estimated by computing the mutual information (MI) between preprocessed EEG and ECG signals, to be then compared across consciousness groups, together with the absolute power and an international qualitative labeling. One-hundred seventy-four patients (73 females, 42%) were included in the study (median age of 65 years [IQR = 20], MCS +: 29, MCS -: 23, UWS: 29). Electroencephalography (EEG) information content was found to be mostly related to the coding of electrocardiography (ECG) activity, i.e., with higher MI (p < 0.05), in Unresponsive Wakefulness Syndrome and Minimally Consciousness State minus (MCS -). EEG-ECG MI, besides clearly discriminating patients in an MCS - and +, significantly differed between lesioned areas (sides) in a subgroup of unilateral hemorrhagic patients. Crucially, such an accessible and non-invasive measure of residual consciousness signs was robust across electrodes and patient groups. Consequently, exiting from a strictly neuro-centric consciousness detection approach may be the key to provide complementary insights for the objective assessment of patients' consciousness levels and for the patient-specific planning of rehabilitative interventions.

Deep phenotyping as a contribution to personalized depression therapy: the GEParD and DaCFail protocols

Depressive patients suffer from a complex of symptoms of varying intensity compromising their mood, emotions, self-concept, neurocognition, and somatic function. Due to a mosaic of aetiologies involved in developing depression, such as somatic, neurobiological, (epi-)genetic factors, or adverse life events, patients often experience recurrent depressive episodes. About 20-30% of these patients develop difficult-to-treat depression. Here, we describe the design of the GEParD (Genetics and Epigenetics of Pharmaco- and Psychotherapy in acute and recurrent Depression) cohort and the DaCFail (Depression-associated Cardiac Failure) case-control protocol. Both protocols intended to investigate the incremental utility of multimodal biomarkers including cardiovascular and (epi-)genetic markers, functional brain and heart imaging when evaluating the response to antidepressive therapy using comprehensive psychometry. From 2012 to 2020, 346 depressed patients (mean age 45 years) were recruited to the prospective, observational GEParD cohort protocol. Between 2016 and 2020, the DaCFail case-control protocol was initiated integrating four study subgroups to focus on heart-brain interactions and stress systems in patients > 50 years with depression and heart failure, respectively. For DaCFail, 120 depressed patients (mean age 60 years, group 1 + 2), of which 115 also completed GEParD, and 95 non-depressed controls (mean age 66 years) were recruited. The latter comprised 47 patients with heart failure (group 3) and 48 healthy subjects (group 4) of a population-based control group derived from the Characteristics and Course of Heart Failure Stages A-B and Determinants of Progression (STAAB) cohort study. Our hypothesis-driven, exploratory study design may serve as an exemplary roadmap for a standardized, reproducible investigation of personalized antidepressant therapy in an inpatient setting with focus on heart comorbidities in future multicentre studies.

Increased sympathetic outflow induced by emotional stress aggravates myocardial ischemia-reperfusion injury via activation of TLR7/MyD88/IRF5 signaling pathway

BACKGROUND AND OBJECTIVE

Emotional stress substantially increases the risk of ischemic cardiovascular diseases. Previous study indicates that sympathetic outflow is increased under emotional stress. We aim to investigate the role of increased sympathetic outflow induced by emotional stress in myocardial ischemia-reperfusion (I/R) injury, and explore the underlying mechanisms.

METHODS AND RESULTS

We used Designer Receptors Exclusively Activated by Designer Drugs technique to activate the ventromedial hypothalamus (VMH), a critical emotion-related nucleus. The results revealed that emotional stress stimulated by VMH activation increased sympathetic outflow, enhanced blood pressure, aggravated myocardial I/R injury, and exacerbated infarct size. The RNA-seq and molecular detection demonstrated that toll-like receptor 7 (TLR7), myeloid differentiation factor 88 (MyD88), interferon regulatory factor 5 (IRF5), and downstream inflammatory markers in cardiomyocytes were significantly upregulated. Emotional stress-induced sympathetic outflow further exacerbated the disorder of the TLR7/MyD88/IRF5 inflammatory signaling pathway. While inhibition of the signaling pathway partially alleviated myocardial I/R injury aggravated by emotional stress-induced sympathetic outflow.

CONCLUSION

Increased sympathetic outflow induced by emotional stress activates TLR7/MyD88/IRF5 signaling pathway, ultimately aggravating I/R injury.

Brain nuclear receptors and cardiovascular function

Brain-heart interaction has raised up increasing attentions. Nuclear receptors (NRs) are abundantly expressed in the brain, and emerging evidence indicates that a number of these brain NRs regulate multiple aspects of cardiovascular diseases (CVDs), including hypertension, heart failure, atherosclerosis, etc. In this review, we will elaborate recent findings that have established the physiological relevance of brain NRs in the context of cardiovascular function. In addition, we will discuss the currently available evidence regarding the distinct neuronal populations that respond to brain NRs in the cardiovascular control. These findings suggest connections between cardiac control and brain dynamics through NR signaling, which may lead to novel tools for the treatment of pathological changes in the CVDs.

Neurological update: use of cardiac troponin in patients with stroke

Cardiac troponin is a specific and sensitive biomarker to identify and quantify myocardial injury. Myocardial injury is frequently detected after acute ischemic stroke and strongly associated with unfavorable outcomes. Concomitant acute coronary syndrome is only one of several possible differential diagnoses that may cause elevation of cardiac troponin after stroke. As a result, there are uncertainties regarding the correct interpretation and optimal management of stroke patients with myocardial injury in clinical practice. Elevation of cardiac troponin may occur as part of a 'Stroke-Heart Syndrome'. The term 'Stroke-Heart Syndrome' subsumes a clinical spectrum of cardiac complications after stroke including cardiac injury, dysfunction, and arrhythmia which may relate to disturbances of autonomic function and the brain-heart axis. In this review, we provide an up-to-date overview about prognostic implications, mechanisms, and management of elevated cardiac troponin levels in patients with acute ischemic stroke.