Systolic and diastolic function in chronic spinal cord injury

Abstract

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 noninjured individuals, when indexed by body surface area (BSA) left ventricle mass [-14 (5) g/ m2, p < .01], end diastolic volume [-6 (3) mL/m 2 , p < .05], and end systolic volume [-4 (1) mL/m 2 , 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.

Novel Clinimetric Toolset to Quantify the Stability of Blood Pressure and Its Application to Evaluate Cardiovascular Function After Spinal Cord Injury

“…For the estimated millions of people living with SCI globally (Singh et al, 2014;Kumar et al, 2018), altered autonomic cardiovascular regulation leads to chronic arterial blood pressure instability (Hubli et al, 2015;Katzelnick et al, 2019) with variation between hypotension that can be exacerbated by orthostasis (e.g., position changes) and severe hypertension triggered by autonomic dysreflexia (Blackmer, 1997;Teasell et al, 2000;Wecht et al, 2003;Dolinak and Balraj, 2007;Krassioukov et al, 2009;Wecht et al, 2013;Zhu et al, 2013). Studies on individuals with chronic SCI have identified blood pressure instability as one of the determinants of cardiovascular morbidity and mortality, including a 4-fold increased stroke risk in the SCI population (Su and Miao, 2005;Jegede et al, 2010;Rothwell et al, 2010;Wu et al, 2012;Muntner et al, 2015;Piatt et al, 2016;Stevens et al, 2016;Parati et al, 2018;Ditterline et al, 2020;Parati et al, 2020). Even in those without SCI, mounting evidence links blood pressure instability during orthostasis with poorer general physical and mental health (Wilkie et al, 1976;Wessely et al, 1990;Pilgrim et al, 1992;Rosengren et al, 1993;Barrett-Connor and Palinkas, 1994;Czajkowska et al, 2010;Vasudev et al, 2011;Regan et al, 2013;Briggs et al, 2016;Briggs et al, 2018;Shanbhag et al, 2018).…”

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

“…Investigation of cardiac adaptation to increased afterload is therefore necessary, particularly as new research from our center has demonstrated that spinal cord epidural stimulation (scES) can normalize arterial blood pressure and mitigate orthostatic hypotension (Aslan et al, 2018;Harkema et al, 2018a;Legg Ditterline et al, 2020). Restoration of cardiovascular function at rest and during orthostatic stress would dramatically increase cardiac demand as individuals with spinal cord injury live with cardiac adaptation to persistent hypotension (Ditterline et al, 2020). Thus, we decided to investigate the effects of scES on cardiac structure and function.…”