Cardiac arrhythmias the first month after acute traumatic spinal cord injury

In-hospital Cardiac Arrest Following Spinal Cord Injury: A Scoping Review

OBJECTIVES

This review aimed to examine the characteristics of patients with spinal cord injury (SCI) who experience in-hospital cardiac arrest (IHCA), as well as the timing, circumstances, and interventions associated with these events.

METHODS

A comprehensive literature search was conducted across multiple databases, including PubMed, Scopus, Cochrane Library, and Igaku Chuo Zasshi Web (in Japanese), for studies published up to 2024. Two independent reviewers screened the literature. Data were extracted from the selected studies regarding the characteristics of patients with SCI who experienced IHCA, the timing of IHCA, the circumstances under which it occurred, and the interventions provided.

RESULTS

A total of 56 studies met the inclusion criteria. IHCA most commonly occurs in patients with complete cervical SCI. The time frame for IHCA occurrence ranged from 1 day and 2.5 months post-injury. IHCA frequently occurs during endotracheal suctioning or postural changes. The most commonly reported intervention for IHCA was the use of a pacemaker.

CONCLUSIONS

In patients with SCI, IHCA is more prevalent among those with severe cervical injuries and is often triggered by procedures such as suctioning or postural adjustments. Physical therapist needs to implement robust risk management strategies. These findings are crucial for both clinical practice and future research.

Application of Vagus Nerve Stimulation in Spinal Cord Injury Rehabilitation

Spinal cord injury (SCI) is a prevalent devastating condition causing significant morbidity and mortality, especially in developing countries. The pathophysiology of SCI involves ischemia, neuroinflammation, cell death, and scar formation. Due to the lack of definitive therapy for SCI, interventions mainly focus on rehabilitation to reduce deterioration and improve the patient's quality of life. Currently, rehabilitative exercises and neuromodulation methods such as functional electrical stimulation, epidural electrical stimulation, and transcutaneous electrical nerve stimulation are being tested in patients with SCI. Other spinal stimulation techniques are being developed and tested in animal models. However, often these methods require complex surgical procedures and solely focus on motor function. Vagus nerve stimulation (VNS) is currently used in patients with epilepsy, depression, and migraine and is being investigated for its application in other disorders. In animal models of SCI, VNS significantly improved locomotor function by ameliorating inflammation and improving plasticity, suggesting its use in human subjects. SCI patients also suffer from nonmotor complications, including pain, gastrointestinal dysfunction, cardiovascular disorders, and chronic conditions such as obesity and diabetes. VNS has shown promising results in alleviating these conditions in non-SCI patients, which makes it a possible therapeutic option in SCI patients.

The susceptibility of cardiac arrhythmias after spinal cord crush injury in rats

High-level spinal cord injury (SCI) often interrupts supraspinal regulation of sympathetic input to the heart. Although it is known that dysregulated autonomic control increases the risk for cardiac disorders, the mechanisms mediating SCI-induced arrhythmias are poorly understood. Here, we employed a rat model of complete spinal cord crush injury at the 2nd/3rd thoracic (T2/3) level to investigate cardiac rhythm disorders resulting from SCI. Rats with T9 injury and naïve animals served as two controls. Four weeks after SCI, rats were implanted with a radio-telemetric device for electrocardiogram and blood pressure monitoring. During 24-h recordings, heart rate variability in rats with T2/3 but not T9 injury exhibited a significant reduction in the time domain, and a decrease in power at low frequency but increased power at high frequency in the frequency domain which indicates reduced sympathetic and increased parasympathetic outflow to the heart. Pharmacological blockade of the sympathetic or parasympathetic branches confirmed the imbalance of cardiac autonomic control. Activation of sympatho-vagal input during the induction of autonomic dysreflexia by colorectal distention triggered various severe arrhythmic events in T2/3 injured rats. Meanwhile, intravenous infusion of the β1-adrenergic receptor agonist, dobutamine, caused greater incidence of arrhythmias in rats with T2/3 injury than naïve and T9 injured controls. Together, the results indicate that high-level SCI increases the susceptibility to developing cardiac arrhythmias likely owing to compromised autonomic homeostasis. The T2/3 crush model is appropriate for studying abnormal cardiac electrophysiology resulting from SCI.

Cardiac arrhythmias six months following traumatic spinal cord injury

OBJECTIVE

To investigate the incidence of cardiac arrhythmias at six months following traumatic spinal cord injury (SCI) and to compare the prevalence of arrhythmias between participants with cervical and thoracic SCI.

DESIGN

A prospective observational study using continuous twenty-four-hour Holter monitoring.

SETTING

Inpatient rehabilitation unit of a university research hospital and patient home setting.

PARTICIPANTS

Fifty-five participants with acute traumatic SCI were prospectively included. For each participant, the SCI was characterized according to the International Standards for Neurological Classification of SCI by the neurological level and severity according to the American Spinal Injury Association Impairment Scale.

OUTCOME MEASURES

Comparisons between demographic characteristics and arrhythmogenic occurrences as early as possible after SCI (4 ± 2 days) followed by 1, 2, 3, 4 weeks and 6 month time points of Holter monitoring.

RESULTS

Bradycardia (heart rate [HR] <50 bpm) was present in 29% and 33% of the participants with cervical (C1-C8) and thoracic (T1-T12) SCI six months after SCI, respectively. The differences in episodes of bradycardia between the two groups were not significant (P < 0.54). The mean maximum HR increased significantly from 4 weeks to 6 months post-SCI (P < 0.001), however mean minimum and maximum HR were not significantly different between the groups at the six-month time point. There were no differences in many arrhythmias between recording periods or between groups at six months.

CONCLUSIONS

At the six-month timepoint following traumatic SCI, there were no significant differences in occurrences of arrhythmias between participants with cervical and thoracic SCI compared to the findings observed in the first month following SCI.

In-hospital mortality in people with complete acute traumatic spinal cord injury at a tertiary care center in India-a retrospective analysis

STUDY DESIGN

This is a retrospective study.

OBJECTIVES

To analyze the causes and risk factors of mortality in people admitted with complete acute traumatic spinal cord injury (ATSCI).

SETTING

The study was performed at the Indian Spinal Injuries Centre, New Delhi.

METHODS

Data between 2000 and 2016 were retrospectively collected from case records of people with ATSCI. Risk factors for mortality were examined using multivariable logistic regression.

RESULTS

Mortality rate in ATSCI admissions (n = 758) during the study period was 10%. Median (IQR) age of study participants was 34 (21) years with a range of 14-85 years. Respiratory complications, septicemia, and cardiovascular causes were responsible for 42%, 28, and 18% of deaths. Mortality rate in people with paraplegia and tetraplegia was 3% and 22%, respectively. The proportion surviving at 6 weeks was significantly different across people with paraplegia and people with high and low tetraplegia (p < 0.001). Greater age (OR (multivariable models) = 1.03, 95% CI = 1.01-1.06), associated injuries (OR = 2.42, 95% CI = 1.11-5.27), high tetraplegia (OR = 5.09, 95% CI = 2.21-11.72), low tetraplegia (OR = 4.84, 95% CI = 1.29-18.09), need for ventilator support (OR = 31.32, 95% CI = 14.92-65.35), septicemia (OR = 4.60, 95% CI = 1.05-20.07), respiratory complications (OR = 3.46, 95% CI = 1.63-7.33), and cardiovascular causes (OR = 39.03, 95% CI = 8.29-183.89) were significant risk factors associated with mortality.

CONCLUSION

Respiratory complications, septicemia, and cardiovascular causes were the commonest causes of in-hospital mortality in people with complete ATSCI. Greater age, presence of associated injuries, tetraplegia, and ventilator support were risk factors significantly associated with mortality. To reduce morbidity and mortality in the acute phase, there is a need to focus on respiratory management and prevention of infections, especially in tetraplegics.

Markers of susceptibility to cardiac arrhythmia in experimental spinal cord injury and the impact of sympathetic stimulation and exercise training

Injury to descending autonomic (sympathetic) pathways is common after high-level spinal cord injury (SCI) and associated with abnormal blood pressure and heart rate regulation. In individuals with high-level SCI, abnormal sympathovagal balance (such as during autonomic dysreflexia; paroxysmal hypertension provoked by sensory stimuli below the injury) is proarrhythmogenic. Exercise training is a key component of SCI rehabilitation and management of cardiovascular disease risk, but it is unclear whether exercise training influences susceptibility to cardiac arrhythmia. We aimed to evaluate: (i) whether susceptibility to arrhythmia increases in a rodent-model of SCI; (ii) the impact of the sympathomimetic drug dobutamine (DOB) on arrhythmia risk; (iii) whether exercise training ameliorates arrhythmia risk. Twenty-one Wistar rats were divided into 3 subgroups: T2-contusive SCI (T2, n = 7), T2-contusive SCI completing passive hindlimb cycling training (PHLC, n = 7), and T10-contusive SCI (T10, n = 7). Known electrocardiographic arrhythmia markers and heart rate variability parameters were evaluated before (PRE), 1-week (POST) and 5-weeks post-SCI (TERM) at baseline and during DOB infusion (30 μg/kg/min). Baseline markers of arrhythmia risk were increased in both T2 and T10 animals. DOB decreased R-R interval (p < 0.001), and increased markers of risk for ventricular arrhythmia, particularly in high-level (T2) animals (p < 0.05). Exercise training blunted the exacerbation of markers of arrhythmia risk in the presence of DOB. Markers of risk for cardiac arrhythmia are increased in experimental SCI, and DOB further increases arrhythmia risk in high-level SCI. Exercise training did not improve markers of arrhythmia risk at rest, but did ameliorate markers of arrhythmia risk during sympathetic stimulation.

Spinal cord infarction in a young patient with methamphetamine abuse

We report a case of a 20-year-old man who was diagnosed with spontaneous spinal cord infarction after abusing methamphetamine for a year. He presented with sudden onset of bilateral upper and lower limb weakness. His MRI spine showed a long segment of high signal intensity seen predominantly in the anterior spinal cord from medulla to mid thoracic level as well as a pencil-like hyperintensity seen postcontrast suggestive of spinal cord ischaemia or infarct. Thus, he was empirically treated for presumed anterior spinal cord infarction. He then developed autonomic dysfunction and went into respiratory distress, which required invasive mechanical ventilation support. Subsequently, he developed cardiac arrythmia with supraventricular tachycardiac followed by asystole and succumbed to illness on day 9 despite maximal resuscitative efforts. This case report illustrates a rare spinal cord infarction caused by methamphetamine intoxication and the importance of identifying and treating it early.

Beneficial Cardiac Structural and Functional Adaptations After Lumbosacral Spinal Cord Epidural Stimulation and Task-Specific Interventions: A Pilot Study

Cardiac myocyte atrophy and the resulting decreases to the left ventricular mass and dimensions are well documented in spinal cord injury. Therapeutic interventions that increase preload can increase the chamber size and improve the diastolic filling ratios; however, there are no data describing cardiac adaptation to chronic afterload increases. Research from our center has demonstrated that spinal cord epidural stimulation (scES) can normalize arterial blood pressure, so we decided to investigate the effects of scES on cardiac function using echocardiography. Four individuals with chronic, motor-complete cervical spinal cord injury were implanted with a stimulator over the lumbosacral enlargement. We assessed the cardiac structure and function at the following time points: (a) prior to implantation; (b) after scES targeted to increase systolic blood pressure; (c) after the addition of scES targeted to facilitate voluntary (i.e., with intent) movement of the trunk and lower extremities; and (d) after the addition of scES targeted to facilitate independent, overground standing. We found significant improvements to the cardiac structure (left ventricular mass = 10 ± 2 g, p < 0.001; internal dimension during diastole = 0.1 ± 0.04 cm, p < 0.05; internal dimension during systole = 0.06 ± 0.03 cm, p < 0.05; interventricular septum dimension = 0.04 ± 0.02 cm, p < 0.05), systolic function (ejection fraction = 1 ± 0.4%, p < 0.05; velocity time integral = 2 ± 0.4 cm, p < 0.001; stroke volume = 4.4 ± 1.5 ml, p < 0.01), and diastolic function (mitral valve deceleration time = -32 ± 11 ms, p < 0.05; mitral valve deceleration slope = 50 ± 25 cm s-1, p < 0.05; isovolumic relaxation time = -6 ± 1.9 ms, p < 0.05) with each subsequent scES intervention. Despite the pilot nature of this study, statistically significant improvements to the cardiac structure, systolic function, and diastolic function demonstrate that scES combined with task-specific interventions led to beneficial cardiac remodeling, which can reverse atrophic changes that result from spinal cord injury. Long-term improvements to cardiac function have implications for increased quality of life and improved cardiovascular health in individuals with spinal cord injury, decreasing the risk of cardiovascular morbidity and mortality.

Ventricular arrhythmia during rehabilitation of cervical spinal cord injury

Patients with cervical spinal cord injury have a high incidence of cardiac arrhythmias, especially in the first 14 to 30 days after traumatic event (acute phase). Electrophysiological abnormalities described in the acute phase are most often bradycardia, which is spontaneous or triggered by various stimuli. In the chronic phase, varied arrhythmias are described, but ventricular arrhythmias as a result of autonomic dysregulation in chronic SCI are rare and isolated. We present the case of a patient with a C5-C6 incomplete spinal cord injury (ASIA-B grade) in which symptomatic ventricular arrhythmia is described one year after the traumatic event.

32-year-old with Paroxysmal Atrial Fibrillation after Traumatic Spinal Cord Injury

A 32-year-old man presented with sudden loss of consciousness after passing urine with resultant trauma to the back of his neck. There were no palpitations prior. Examination revealed flaccid paralysis of all 4 limbs with priapism. Electrocardiogram demonstrated atrial fibrillation with rapid ventricular response. Laboratory showed normal potassium, magnesium, calcium, thyroid stimulating hormone and troponin I levels. Magnetic resonance imaging of the cervical spine demonstrated left C4 facet dislocation with grade 1 spondylolisthesis of C4 over C5, with moderate to severe narrowing of the spinal canal with cord compression and oedema. Transthoracic echocardiogram demonstrated an ejection fraction of 60% and no valvular abnormalities. Left atrium size was normal. The atrial fibrillation subsequently spontaneously reverted to sinus rhythm without treatment. Clinicians should be aware that atrial fibrillation can occur in the context of traumatic spinal cord injury due to disruption of the autonomic pathways in the cervical spine.

Systolic and diastolic function in chronic spinal cord injury

Individuals with spinal cord injury develop cardiovascular disease more than age-matched, non-injured cohorts. However, progression of systolic and diastolic dysfunction into cardiovascular disease after spinal cord injury is not well described. We sought to investigate the relationship between systolic and diastolic function in chronic spinal cord injury to describe how biological sex, level, severity, and duration of injury correlate with structural changes in the left ventricle. Individuals with chronic spinal cord injury participated in this study (n = 70). Registered diagnostic cardiac sonographers used cardiac ultrasound to measure dimensions, mass, and systolic and diastolic function of the left ventricle. We found no significant relationship to severity or duration of injury with left ventricle measurements, systolic function outcome, or diastolic function outcome. Moreover, nearly all outcomes measured were within the American Society of Echocardiography-defined healthy range. Similar to non-injured individuals, when indexed by body surface area (BSA) left ventricle mass [-14 (5) g/m2, p < .01], end diastolic volume [-6 (3) mL/m², p < .05], and end systolic volume [-4 (1) mL/m², p < .01] were significantly decreased in women compared with men. Likewise, diastolic function outcomes significantly worsened with age: E-wave velocity [-5 (2), p < .01], E/A ratio [-0.23 (0.08), p < .01], and e’ velocity [lateral: -1.5 (0.3) cm/s, p < .001; septal: -0.9 (0.2), p < .001] decreased with age while A-wave velocity [5 (1) cm/s, p < .001] and isovolumic relaxation time [6 (3) ms, p < .05] increased with age. Women demonstrated significantly decreased cardiac size and volumes compared with men, but there was no biological relationship to dysfunction. Moreover, individuals were within the range of ASE-defined healthy values with no evidence of systolic or diastolic function and no meaningful relationship to level, severity, or duration of injury. Decreases to left ventricular dimensions and mass seen in spinal cord injury may result from adaptation rather than maladaptive myocardial remodeling, and increased incidence of cardiovascular disease may be related to modifiable risk factors.

Thoracic sympathetic nuclei ischemia: Effects on lower heart rates following experimentally induced spinal subarachnoid hemorrhage

BACKGROUND

The neuropathological mechanism of heart rhythm disorders, following spinal cord pathologies, to our knowledge, has not yet been adequately investigated. In this study, the effect of the ischemic neurodegeneration of the thoracic sympathetic nuclei (TSN) on the heart rate (HR) was examined following a spinal subarachnoid hemorrhage (SSAH).

METHODS

This study was conducted on 22 rabbits. Five rabbits were used as a control group, five as SHAM, and twelve as a study group. The animals' HRs were recorded via monitoring devices on the first day, and those results were accepted as baseline values. The HRs were remeasured after injecting 0.5 cc of isotonic saline for SHAM and 0.5 cc of autolog arterial blood into the thoracic spinal subarachnoid space at T4-T5 for the study group. After a three-week follow-up with continuous monitoring of their HRs, the rabbit's thoracic spinal cords and stellate ganglia were extracted. The specimens were evaluated by histopathological methods. The densities of degenerated neurons in the TSN and stellate ganglia were compared with the HRs.

RESULTS

The mean HRs and mean degenerated neuron density of the TSN and stellate ganglia in control group were 251±18/min, 5±2/mm³, and 3±1/mm³, respectively. The mean HRs and the mean degenerated neuron density of the TSN and stellate ganglia were detected as 242±13/min, 6±2/mm³, and 4±2/mm³ in SHAM (P>0.05 vs. control); 176±19/min, 94±12/mm³, and 28±6/mm³ in the study group (P<0.0001 vs. control and P<0.005 vs. SHAM), respectively.

CONCLUSIONS

SAH induced TSN neurodegeneration may have been responsible for low HRs following SSAH. To date this has not been mentioned in the literature.

A Cryptic Cause of Cardiac Arrest

BACKGROUND

RIPPLY2-associated spondylocostal dysostosis is a rare disorder that leads to segmentation defects of the vertebrae. These vertebral defects can result in severe instability of the cervical spine, leading to cardiac arrest after only minor whiplash injury.

CASE REPORT

We present the case of a healthy 7-year-old child who experienced an out-of-hospital cardiac arrest. He was reported to have profound respiratory distress and collapsed after going down a slide, without trauma. He was resuscitated in the field, and presented to the emergency department, where return of spontaneous circulation was achieved. Imaging of his cervical spine revealed multiple abnormalities. It was determined that a whiplash injury led to hypoxia and bradycardia due to the anatomic abnormalities of his cervical spine, resulting in cardiovascular collapse. He recovered fully and was later diagnosed with SCDO6, an autosomal recessive inherited disorder caused by a mutation in the RIPPLY2 gene. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Unfamiliarity of providers with this mechanism of cardiac arrest, and the rarity of the syndrome itself, make early recognition very difficult. Late diagnosis and lack of preventative measures, including immediate cervical spine stabilization, can lead to catastrophic outcomes. In patients with cardiac arrest of unclear etiology, early consideration of cervical spine immobilization and evaluation can be lifesaving.

Management of acute traumatic spinal cord injuries

Acute traumatic spinal cord injury (SCI) is a devastating disease process affecting tens of thousands of people across the USA each year. Despite the increase in primary prevention measures, such as educational programs, motor vehicle speed limits, automobile running lights, and safety technology that includes automobile passive restraint systems and airbags, SCIs continue to carry substantial permanent morbidity and mortality. Medical measures implemented following the initial injury are designed to limit secondary insult to the spinal cord and to stabilize the spinal column in an attempt to decrease devastating sequelae. This chapter is an overview of the contemporary management of an acute traumatic SCI patient from the time of injury through the stay in the intensive care unit. We discuss initial triage, immobilization, and transportation of the patient by emergency medical services personnel to a definitive treatment facility. Upon arrival at the emergency department, we review initial trauma protocols and the evidence-based recommendations for radiographic evaluation of the patient's vertebral column. Finally, we outline closed cervical spine reduction and various aggressive medical therapies aimed at improving neurologic outcome.

Contemporary Cardiovascular Concerns after Spinal Cord Injury: Mechanisms, Maladaptations, and Management

Cardiovascular (CV) issues after spinal cord injury (SCI) are of paramount importance considering they are the leading cause of death in this population. Disruption of autonomic pathways leads to a highly unstable CV system, with impaired blood pressure (BP) and heart rate regulation. In addition to low resting BP, on a daily basis the majority of those with SCI suffer from transient episodes of aberrantly low and high BP (termed orthostatic hypotension and autonomic dysreflexia, respectively). In fact, autonomic issues, including resolution of autonomic dysreflexia, are frequently ranked by individuals with high-level SCI to be of greater priority than walking again. Owing to a combination of these autonomic disturbances and a myriad of lifestyle factors, the pernicious process of CV disease is accelerated post-SCI. Unfortunately, these secondary consequences of SCI are only beginning to receive appropriate clinical attention. Immediately after high-level SCI, major CV abnormalities present in the form of neurogenic shock. After subsiding, new issues related to BP instability arise, including orthostatic hypotension and autonomic dysreflexia. This review describes autonomic control over the CV system before injury and the mechanisms underlying CV abnormalities post-SCI, while also detailing the end-organ consequences, including those of the heart, as well as the systemic and cerebral vasculature. The tertiary impact of CV dysfunction will also be discussed, such as the potential impediment of rehabilitation, and impaired cognitive function. In the recent past, our understanding of autonomic dysfunctions post-SCI has been greatly enhanced; however, it is vital to further develop our understanding of the long-term consequences of these conditions, which will equip us to better manage CV disease morbidity and mortality in this population.