Cardiovascular response to peak voluntary exercise in males with cervical spinal cord injury

Abstract

Context/objective: Traumatic damage to the cervical spinal cord is usually associated with a disruption of the autonomic nervous system (ANS) and impaired cardiovascular control both during and following exercise. The magnitude of the cardiovascular dysfunction remains unclear. The aim of the current study was to compare cardiovascular responses to peak voluntary exercise in individuals with tetraplegia and able-bodied participants.

Design: A case-control study.

Subjects: Twenty males with cervical spinal cord injury (SCI) as the Tetra group and 27 able-bodied males as the Control group were included in the study.

Outcome measures: Blood pressure (BP) response one minute after the peak exercise, peak heart rate (HRpeak), and peak oxygen consumption (VO2peak) on an arm crank ergometer were measured. In the second part of the study, 17 individuals of the Control group completed the Tetra group's workload protocol with the same parameters recorded.

Results: There was no increase in BP in response to the exercise in the Tetra group. Able-bodied individuals exhibited significantly increased post-exercise systolic BP after the maximal graded exercise test (123±16%) and after completion of the Tetra group's workload protocol (114±11%) as compared to pre-exercise. The Tetra group VO2peak was 59% and the HRpeak was 73% of the Control group VO2peak and HRpeak, respectively.

Conclusions: BP did not increase following maximal arm crank exercise in males with a cervical SCI unlike the increases observed in the Control group. Some males in the Tetra group appeared to be at risk of severe hypotension following high intensity exercise, which can limit the ability to progressive increase and maintain high intensity exercise.

Keywords: Blood pressure; Cardiovascular system; Exercise; Spinal cord trauma; Tetraplegia.

Figures

Figure 1.

Workload protocol of the arm crank exercise test as expressed in mean W·kg−1; peak voluntary stop between the 8 and 12 minutes (grey area).

Figure 2.

Systolic blood pressure (SBP) following five minutes lying supine, following five minutes seated rest with the trunk supported at 60° and one minute after the peak voluntary exercise on an arm crank ergometer in the Tetra group (black), in the Control group (white), and in the Control group submax (white); mean  ±  standard deviation (SD). 1 Tetra group; after the peak voluntary arm exercise (0.7 W·kg−1). 2 Control group submax; after the submaximal voluntary arm exercise (0.7 W·kg−1). 3 Control group; after the peak voluntary arm exercise (1.4 W·kg−1).