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Cardiac dysrhythmias associated with central nervous system dysfunction
1College of Nursing, Arizona State University, Tempe 85287-2602.
Insights
Intracranial pathology can cause lethal cardiac dysrhythmias due to autonomic dysfunction. Specific brain regions and nerves influence heart rate and rhythm, affecting outcomes.
Area of Science:
- Neurology
- Cardiology
- Autonomic Neuroscience
Background:
- Intracranial pathology frequently leads to cardiac dysrhythmias, including potentially fatal arrhythmias.
- Conditions like stroke, hemorrhage, seizures, and head trauma are linked to myocardial damage and ECG abnormalities.
- Autonomic nervous system dysfunction is implicated in these cardiac disturbances.
Purpose of the Study:
- To explore the association between intracranial pathology and cardiac dysrhythmias.
- To investigate the role of the autonomic nervous system in mediating these cardiac events.
- To examine potential lateralized functions within the brain influencing cardiac rhythm.
Main Methods:
- Review of existing literature linking neurological conditions with cardiac dysrhythmias.
- Analysis of autonomic nervous system pathways involved in neural input to the heart.
- Examination of experimental and human data on brain stimulation and cardiac responses.
Main Results:
- Observed cardiac dysrhythmias include T-wave changes, altered intervals (P-R, Q-T), and various ectopic beats and tachycardias/bradycardias.
- Autonomic derangements are identified as the cause of these rate, rhythm, and conduction disturbances.
- Evidence suggests lateralized brain function: right insular cortex stimulation is linked to tachycardia, while left insular cortex stimulation is associated with bradycardia.
Conclusions:
- Intracranial pathology significantly impacts cardiac function through autonomic pathways.
- Specific brain regions and vagal nerve stimulation exhibit lateralized effects on cardiac rhythm.
- Further research is needed to fully elucidate the specific neuropathological correlates of observed dysrhythmias.
Abstract:
Intracranial pathology is frequently associated with cardiac dysrhythmias, which are sometimes lethal. Stroke, subarachnoid hemorrhage, seizures and head trauma with or without increased intracranial pressure are observed to be accompanied by myocardial damage and by ECG abnormalities, including T-wave changes, shortened P-R interval, prolonged Q-T interval, premature ventricular contractions, ventricular ectopy, sinus bradycardia, ventricular and supraventricular tachycardias. Derangements of autonomic function have been shown to be responsible for these disturbances of rate, rhythm and conduction. The autonomic nervous system receives neural input from various parts of the cerebral cortex, the hypothalamus and the brainstem which are extensively interconnected. Although unequivocal data supporting associations between specific neuropathological conditions or damage to specific structures and the observed dysrhythmias do not exist, some evidence for laterality of function does exist in humans. Tachycardia and pressor responses are more common after stimulation of the right insular cortex and after experimental stimulation of the left vagus which innervates the atrioventricular node and the cardiac conduction system. Bradycardia seems to be more common after stimulation of the left insular cortex or the right vagus nerve which innervate the sinoatrial node.