Head Rules Over the Heart: Cardiac Manifestations of Cerebral Disorders

Abstract

The Brain-Heart interaction is becoming increasingly important as the underlying pathophysiological mechanisms become better understood. "Neurocardiology" is a new field which explores the pathophysiological interplay of the brain and cardiovascular systems. Brain-heart cross-talk presents as a result of direct stimulation of some areas of the brain, leading to a sympathetic or parasympathetic response or it may present as a result of a neuroendocrine response attributing to a clinical picture of a sympathetic storm. It manifests as cardiac rhythm disturbances, hemodynamic perturbations and in the worst scenarios as cardiac failure and death. Brain-Heart interaction (BHI) is most commonly encountered in traumatic brain injury and subarachnoid hemorrhage presenting as dramatic electrocardiographic changes, neurogenic stunned myocardium or even as ventricular fibrillation. A well-known example of BHI is the panic disorders and emotional stress resulting in Tako-tsubo syndrome giving rise to supraventricular and ventricular tachycardias and transient left ventricular dysfunction. In this review article, we will discuss cardiovascular changes caused due to the disorders of specific brain regions such as the insular cortex, brainstem, prefrontal cortex, hippocampus and the hypothalamus; neuro-cardiac reflexes namely the Cushing's reflex, the Trigemino-cardiac reflex and the Vagal reflex; and other pathological states such as neurogenic stunned myocardium /Takotsubo cardiomyopathy. There is a growing interest among intensivists and anesthesiologists in brain heart interactions as there are an increasing number of cases being reported and there is a need to address unanswered questions, such as the incidence of these interactions, the multifactorial pathogenesis, individual susceptibility, the role of medications, and optimal management.

Key messages: BHI contribute in a significant way to the morbidity and mortality of neurological conditions such as traumatic brain injury, subarachnoid hemorrhage, cerebral infarction and status epilepticus. Constant vigilance and a high index of suspicion have to be exercised by clinicians to avoid misdiagnosis or delayed recognition. The entire clinical team involved in patient care should be aware of brain heart interaction to recognize these potentially life-threatening scenarios.

How to cite this article: Hrishi AP, Lionel KR, Prathapadas U. Head Rules Over the Heart: Cardiac Manifestations of Cerebral Disorders. Indian J Crit Care Med 2019;23(7):329-335.

Keywords: Neurocardiac axis; Neurocardiology; Neurological disorders.

Fig. 1

ECG (electrocardiogram) showing supraventricular tachyarrythmia in a patient who has had left insular stroke

Fig. 2

This figure shows the central and peripheral mechanism of the heart and brain interaction and the clinical symptoms and ECG changes which are encountered on triggering specific brain regions. Among the regions insular cortex, prefrontal cortex, hippocampus, and brainstem play an important role in interplay between the nervous system and the cardiovascular system

Figs 3A and B

(A) Schematic illustration of the ‘catecholamine hypothesis mechanism’ responsible for neurogenic stress cardiomyopathy after acute brain injury; (B) Schematic illustration of the pathophysiology for ‘Takotsubo Cardiomyopathy’. Both these pathologies can induce secondary brain damage by impaired systemic and brain homeostasis. Abbreviations :CPP, cerebral perfusion pressure

Fig. 4

ECG (electrocardiogram) showing global ST segment depression and T inversion in all the leads which is encountered in both neurogenic stunned myocardium and takotsubo cardiomyopathy.

Fig. 5

Table showing the differences between stress cardiomyopathy (Takotsubo cardiomyopathy) and neurogenic stunned myocardium. Abbreviations: ECG, electrocardiogram; ICH, intracranial hemorrhage; RWMAs, regional wall motion abnormalities; SAH, subarachnoid hemorrhage; TBI, traumatic brain injury.