Impact of a Right Ventricular Impedance Sensor on the Cardiovascular Responses to Exercise in Pacemaker Dependent Patients

Background. The evaluation of the heart rate (HR) response to exercise is important for the assessment of the rate response algorithm of sensor-controlled pacemakers. This study examined the effects of a right ventricular impedance sensor driven pacemaker on the cardiovascular responses to incremental exercise in pacemaker dependent patients. Methods. Twelve patients (70.5 ± 9.5 years; 5 Females: 7 Males) implanted with an Inos2+ closed loop stimulation (CLS) pacemaker were compared to 12 healthy age and sex matched controls (70.6 ± 4.8 years). All subjects performed the chronotropic assessment exercise protocol (CAEP). Variables of interest included HR, cardiac output (Q), oxygen uptake (Vo2) and blood pressure (BP). Data were analyzed at rest, throughout exercise and during recovery. Furthermore, patient chronotropic responses were compared to a reference chronotropic response slope for aerobic exercise. Results. There were no differences between groups for HR or Q. response throughout exercise. At peak exercise, V.o2 (mL.kg-1.min-1) was higher for the controls (p < 0.05). The patient chronotropic response slope was comparable to the CAEP reference slope from rest to both the anaerobic threshold (AT) and peak exercise. During recovery, no differences were observed between the groups for any parameters or for the HR decay slopes. Conclusions. Up to the anaerobic threshold, the right ventricular impedance sensor driven pacemaker delivered a pacing rate that contributed to an overall cardiovascular response similar to that observed in healthy age matched subjects

SenseWear Armband and Stroke: Validity of Energy Expenditure and Step Count Measurement during Walking

The purpose of this study was to test the validity of the SenseWear Pro Armband (SWA) for the measurement of energy expenditure (EE) and step count against a criterion in persons with stroke. Twelve participants with chronic stroke (mean age 64.2 ± 10.4 years; mean gait speed 0.67 ± 0.25 m/sec) completed two trials of a six-minute walk test, while wearing a SenseWear Armband (SWA) on each arm and being continuously monitored using a portable metabolic cart. Agreement between estimates of energy expenditure from the SWA and the metabolic cart was fair for the armband on the hemiplegic arm (intraclass correlation cefficient (ICC) = 0.586) and good for the armband on the unaffected arm (ICC = 0.702). Agreement between the SWA estimate of step count, and step count as measured by the Step Activity Monitor was poor (ICC < 0.352), with significant underestimation by the SWA. Our results show that, for these moderately impaired persons with stroke, the SWA should be used with caution for the measurement of energy expenditure and should not be used to measure step count

Impact of a right ventricular impedance sensor on the cardiovascular responses to exercise in pacemaker dependent patients

BACKGROUND: The evaluation of the heart rate (HR) response to exercise is important for the assessment of the rate response algorithm of sensor-controlled pacemakers. This study examined the effects of a right ventricular impedance sensor driven pacemaker on the cardiovascular responses to incremental exercise in pacemaker dependent patients. METHODS: Twelve patients (70.5 ± 9.5 years; 5 Females: 7 Males) implanted with an Inos (2+) closed loop stimulation (CLS) pacemaker were compared to 12 healthy age and sex matched controls (70.6 ± 4.8 years). All subjects performed the chronotropic assessment exercise protocol (CAEP). Variables of interest included HR, cardiac output (Q), oxygen uptake (Vo(2)) and blood pressure (BP). Data were analyzed at rest, throughout exercise and during recovery. Furthermore, patient chronotropic responses were compared to a reference chronotropic response slope for aerobic exercise. RESULTS: There were no differences between groups for HR or Q response throughout exercise. At peak exercise, Vo(2) (mL.kg(-1).min(-1)) was higher for the controls (p < 0.05). The patient chronotropic response slope was comparable to the CAEP reference slope from rest to both the anaerobic threshold (AT) and peak exercise. During recovery, no differences were observed between the groups for any parameters or for the HR decay slopes. CONCLUSION: Up to the anaerobic threshold, the right ventricular impedance sensor driven pacemaker delivered a pacing rate that contributed to an overall cardiovascular response similar to that observed in healthy age matched subjects

Augmented Rehabilitation Program for Patients 60 Years and Younger Following Total Hip Arthroplasty&mdash;Feasibility Study

The purpose of this study is to examine the feasibility, safety and outcomes of a study comparing a 6-week post-operative rehabilitation program to usual care in patients &le;60 years undergoing elective unilateral total hip arthroplasty (THA). Methods: A cohort of 24 THA patients were recruited during their 6-week postoperative visit to their surgeons. The community-based rehabilitation program, which was designed to improve function and increase activity, consisted of 12 structured exercise classes on land and water over 6 weeks. Physical activity was assessed using a Sense Wear Pro Armband (SWA). Participants completed the Hip Osteoarthritis Outcome Score (HOOS) and THA satisfaction questionnaire before and immediately after the intervention. Results: 14 participants received the augmented rehabilitation, and 10 participants were in the control group. All except one in the intervention group completed at least 80% of the sessions. The intervention group took significantly more steps/day (mean difference = 2440 steps/day, 95% CI = 1678, 4712) (p &lt; 0.05), at the follow-up compared to baseline. The intervention group had a higher mean change of number of weekly PA bouts than the control group. Within the intervention group, all HOOS subscales were significantly higher at the follow-up compared to baseline. Conclusion: Findings provided pragmatic insight regarding the intervention and assessments of implementing an augmented rehabilitation program for elective THA