Parkinson's Disease and the Cardiac Cycle: A Rapid Literature Review and Case Series.

BACKGROUND AND OBJECTIVES: Cardiac function in patients with Parkinson's Disease (PD) is not well understood. We conducted a review of the literature to summarize all available data on the cardiac cycle in patients with PD and followed up the review with a case series to describe the cardiac cycle timing intervals in this patient population. METHODS: Using the search terms ("Cardiac cycle" OR "echocardiography" OR "LVET" OR "IVCT" OR "IVRT" OR "LVEF" OR "Systolic Dysfunction" OR "Diastolic Dysfunction") AND ("Parkinson's Disease"), 514 studies were found with 19 included in the review. RESULTS: Studies focused on the impact of medication, the presence of autonomic dysfunction, and resting-state, descriptive observational studies which considered the cardiac cycle. While inconsistent, the evidence suggests that patients with PD have some systolic dysfunction, with recent research implying the presence of subclinical systolic dysfunction. From the case series, 13 participants with PD were included and collected cardiac data daily for 6 weeks. Heart rate was consistent on a weekly basis at 67-71 bpm. Mean week-by-week cardiac parameters were also consistent with the systolic time interval at 332-348 ms, isovolumic relaxation time at 92-96 ms, and isovolumic contraction time at 34-36 ms. CONCLUSION: These timing intervals add valuable normative values for this patient population and the review of the literature suggests that more research is required to better understand cardiac cycle timing intervals in patients with Parkinson's Disease.

Effect of Equal Volume, High-Repetition Resistance Training to Volitional Fatigue, With Different Workout Frequencies, on Muscle Mass and Neuromuscular Performance in Postmenopausal Women.

ABSTRACT: Grzyb, K, Candow, DG, Schoenfeld, BJ, Bernat, P, Butchart, S, and Neary, JP. Effect of equal volume, high-repetition resistance training to volitional fatigue, with different workout frequencies, on muscle mass and neuromuscular performance in postmenopausal women. J Strength Cond Res 36(1): 31-36, 2022-This study examined the effects of equal volume, high-repetition resistance training (HRRT) performed to volitional fatigue, with different workout frequencies, on muscle mass and neuromuscular performance (strength, endurance) in untrained postmenopausal women. Subjects were randomized to perform HRRT 2 d·wk-1 (HRRT-2; 3 sets of 20-30 repetitions/set for elbow and knee flexion and extension) or 3 d·wk-1 (HRRT-3; 2 sets of 20-30 repetitions/set per exercise) for 8 weeks. Baseline and post-training assessments were made for muscle thickness, strength (1 repetition maximum [1RM]) and endurance (number of repetitions performed at 50% baseline 1RM) for elbow and knee flexor and extensor muscle groups. Significance was set at p < 0.05. There was a significant increase over time for all measures of muscle thickness, strength, and endurance (p < 0.005), with no differences between groups. Untrained postmenopausal women can expect to achieve similar improvements in muscle size, strength, and endurance when training 2 or 3 days per week, provided total weekly training volume is equal.

Effects of high-velocity resistance training and creatine supplementation in untrained healthy aging males.

The purpose was to investigate the effects of high-velocity resistance training (HVRT) and creatine supplementation in untrained healthy aging males. Participants were randomized to supplement with creatine (0.1 g·kg-1·day-1 of creatine + 0.1 g·kg-1·day-1 of maltodextrin) or placebo (0.2 g·kg-1·day-1 of maltodextrin) during 8 weeks of HVRT. Prior to and following HVRT and supplementation, assessments were made for muscle strength, muscle thickness, peak torque, and physical performance. There was a significant increase over time for all measures of muscle strength (p < 0.001), muscle thickness (p < 0.001), and some measures of peak torque (knee flexion; 1.05 and 3.14 rad/s; p < 0.001) and physical performance (balance board time-to-completion; p = 0.017). There was a group × time interaction for leg press strength (p = 0.044) and total lower-body strength (leg press, knee flexion, knee extension combined; p = 0.039). The creatine group experienced greater gains in leg press and total lower-body strength compared with the placebo group, with no other differences. HVRT increases muscle strength, muscle thickness, and some measures of peak torque and physical performance in untrained healthy aging males. The addition of creatine supplementation to HVRT further augments the gains in leg press and total lower-body strength. Novelty High-velocity resistance training increases muscle mass and performance. Creatine supplementation increases lower-body muscle strength. High-velocity resistance training and creatine supplementation are safe interventions for aging adults.