Alterations in cardiac autonomic control in spinal cord injury.

A spinal cord injury (SCI) interferes with the autonomic nervous system (ANS). The effect on the cardiovascular system will depend on the extent of damage to the spinal/central component of ANS. The cardiac changes are caused by loss of supraspinal sympathetic control and relatively increased parasympathetic cardiac control. Decreases in sympathetic activity result in heart rate and the arterial blood pressure changes, and may cause arrhythmias, in particular bradycardia, with the risk of cardiac arrest in those with cervical or high thoracic injuries. The objective of this review is to give an update of the current knowledge related to the alterations in cardiac autonomic control following SCI. With this purpose the review includes the following subheadings: 2. Neuro-anatomical plasticity and cardiac control 2.1 Autonomic nervous system and the heart 2.2 Alteration in autonomic control of the heart following spinal cord injury 3. Spinal shock and neurogenic shock 3.1 Pathophysiology of spinal shock 3.2 Pathophysiology of neurogenic shock 4. Autonomic dysreflexia 4.1 Pathophysiology of autonomic dysreflexia 4.2 Diagnosis of autonomic dysreflexia 5. Heart rate/electrocardiography following spinal cord injury 5.1 Acute phase 5.2 Chronic phase 6. Heart rate variability 6.1 Time domain analysis 6.2 Frequency domain analysis 6.3 QT-variability index 6.4 Nonlinear (fractal) indexes 7. Echocardiography 7.1 Changes in cardiac structure following spinal cord injury 7.2 Changes in cardiac function following spinal cord injury 8. International spinal cord injury cardiovascular basic data set and international standards to document the remaining autonomic function in spinal cord injury.