Table 2. Summary of studies reporting cardiovascular function in chronic neurological and/or autonomically complete versus incomplete SCI.
| Study | Level | N | Method | Outcome measures | Main findings | Statistics |
|---|---|---|---|---|---|---|
| Grimm (1995)27 | C | 14 (7) | AIS | HRV at rest and in response to provocation | 1. Cervical incomplete exhibited a higher LF component of HRV at rest. 2. Cervical incomplete exhibited a higher LF & HF component of HRV in response to HUT. 3. Cervical incomplete exhibited a higher LF component of HRV in response to provocation. |
Yes |
| Grimm (1997)22 | C LT |
20 (10) 10 (ns) |
AIS | SBP, DBP, HR, HRV at rest and in response to provocation | 1. No between-group differences in SBP, DBP, or HR at rest or in response to HUT 2. Cervical incomplete exhibited a higher LF and HF spectral component of HRV at rest and in response to provocation. |
Yes |
| Curt (1997)6 | C LT |
22 (11) 9 |
AIS | SSR, 24-h BP monitoring, urodynamic examination | 1. Cervical incomplete individuals exhibited normal BP rhythmicity, whereas 91% of cervical complete individuals did not. 2. AD was evident in 27% of cervical incomplete and 91% of cervical complete. |
Yes |
| Helkowski (2003)24 | C | 332 (ns) | AIS | Incidence of AD | 1. Incidence of AD was higher in AIS A&B vs AIS C&D. | Yes |
| De Carvalho (2005)25 | C | 31 (12) | AIS | VO2, VCO2, HR, VE, RER | 1. No differences in any variable between complete and incomplete at rest | Yes |
| Rosada-Rivera (2011)21 | C HT LT |
20 (6) 10 (2) 9 (0) |
AIS | SBP, HR, HRV | 1. No differences in any variable between complete and incomplete | No |
| Sahota (2012)23 | N. comp N. incomp A. comp A. incomp |
17 9 12 14 |
AIS; BPV and NA | SBP, SV, TPR, CBFV at rest and in response to HUT | 1. No differences in any variable between neurological complete and incomplete 2. Autonomically incomplete individuals exhibited an increased SBP and HR at rest and during HUT. |
Yes |
| Ravenbergen (2012)28 | N.comp N. incomp A. comp A. incomp |
18 9 13 15 |
AIS; SSR, BPV, and NA | ECG intervals and variability | 1. No differences in ECG intervals between neurological or autonomic complete and incomplete 2. Tpeak-Tend and QTVI variability was increased in autonomically complete |
Yes |
Note: A. comp = autonomic complete; AD = autonomic dysreflexia; A. incomp = autonomic incomplete; BP = blood pressure; AIS = American Spinal Injury Association Impairment Scale; BPV = blood pressure variability; C = cervical; CBFV = cerebral blood flow velocity; DBP = diastolic blood pressure; ECG = electrocardiogram; HF = high frequency; HT = high-thoracic; HRV = heart rate variability; HUT = head-up tilt; LF = low-frequency; LT = low thoracic; n = total number of participants (values in parentheses represent number of incomplete participants); NA = noradrenaline; N. comp = neurological complete; N. incomp = neurological incomplete; ns = not stated; QTVI = QT variability index; RER = respiratory exchange ratio; SBP = systolic blood pressure; SSR = sympathetic skin response; SV = stroke volume; Tpeak-Tend = interval between the peak and end of the T wave; TPR = total peripheral resistance; VCO2 = carbon dioxide production; VE = minute ventilation; VO2 = oxygen uptake.