Acute effects of water-based exercise versus land-based exercise on ambulatory blood pressure and heart rate variability in heart transplant recipients

Heart transplantation (TX) is a recognized procedure of choice for refractory heart failure, resulting in improvement in symptoms and quality of life of patients. However, these patients have reduced physical capacity and high prevalence of comorbidities. Immunosuppressive therapy and post-surgery cardiac denervation make systemic hypertension (SH) the most prevalent comorbiditie. We evaluated the acute effect of aerobic heated water-based exercise and land-based exercise on the dynamic tension behavior in blood pressure for 24 hours (24-h ABP) and autonomic activity of the heart. Eighteen patients (6 females) clinically stable (5 ± 0.7 years of surgery), 45.7 ± 2.7 years old, underwent 30 minutes of aerobic exercise in the swimming pool, aerobic exercise on a treadmill (land) or non-exercise control (control) in random order (2–5 days between each session). Exercise intensity was set at 11–13 in the 6– 20 rating of perceived exertion scale. We evaluated the heart rate variability (HRV) at the beginning, right after exercise and during the recovery phase, and the 24-h ABP after each session. After water-based exercise, significant reductions were observed in relation to the control session on hourly average systolic blood pressure (SBP) in the first three hours (15h = 12.2 ± 3.1 mmHg, p = 0.004; 16h = 11.1 ± 2.8 mmHg, p = 0.003; 17h = 12.3 ± 3.1 mmHg, p = 0.003) and after the seventh time (21h = 7.8 ± 1.7 mmHg, p = 0.001) analysis, and the daily averages (4 ± 1.6 mmHg, p = 0.02) and hourly average diastolic blood pressure (DBP) in the first (15h = 7.7 ± 2.8 mmHg, p = 0.04) and seventh hours ( 21h = 6.6 ± 1.5 mmHg, p = 0.002). After land-based exercise significant reductions were observed when compared to control session in the hourly averages of SBP during the second (16h = 5.3 ± 1.6 mmHg, p = 0.01), third (17h = 7.3 ± 2 , 3 mm Hg, p = 0.02) and twenty-first time (= 11h 7.8 ± 1.7 mmHg, p = 0.02) and in hourly averages DBP during the second (= 16h 5.0 ± 1 7 mm Hg, p = 0.04), the twenty-first (11h = 8.3 ± 2.5 mmHg, p = 0.01) and twenty fourth hour (14h = 6.9 ± 2.4 mmHg, p = 0 03) analysis. HRV showed no significant difference in any of exercise interventions. Therefore, both exercise sessions promoted similar reductions in ambulatory blood pressure of post-TX patients, suggesting that they can be an important tool to counteract hypertension in this high-risk population.