Abstract 638: Autonomic Cardiovascular Control Responses To Inspiratory Muscle Training And Aerobic Training In Hypertensive Patients

Abstract

Arterial hypertension is characterized by autonomic cardiovascular control imbalance, especially by sympathetic hyperactivity and reduction of vagal modulation. Aerobic training (AT) is highly recommended and Inspiratory muscle training (IMT) has demonstrated beneficial effects in this population as well. We sought to observe the effects of both training modalities in patients with controlled arterial hypertension. 13 patients (55±4 years old, both genders) were included and allocated in three groups: IMT (n=4, 7days/week, 30min/day, load=30%PImax), AT (n=4, 2days/week, 1hour/day, load=70%HRmax) and Control (n=5). Training protocols were performed during 12 weeks. Blood pressure (BP) and heart rate (HR) signals were recorded before and after protocols by pulse telemetry (Finometer®PRO) and ECG (PowerLab®). Autonomic cardiovascular control components were evaluated in time and frequency domains and arterial baroreflex function was analysed by sequence method. The analysis of blood pressure variability components demonstrated that IMT reduced time domain BP Variability (BPV) (SD: IMT=5.52(±3.04)vs11.93(±7.27)mmHg, AT=8.23(±1.8)vs5.16(±1.8)mmHg) as well as sympathetic component of BPV (LFabs: IMT=4.4(2.55)vs10.09(±9.64)mmHg 2 ; AT=7.15(±4.13)vs6.27(±2.03)mmHg 2 ). In relation to HR variability components, we observed increase of vagal modulation after IMT (HFun: IMT=71.75(13.9)vs65.26(±36.2), AT=55.75(10.07)vs60(15.9)) probably leading to benefits in simpathovagal balance in this group (LH/HF: IMT=0.51(±0.2)vs2.22(±0.4), AT=1.2(±0.5)vs0.96(±0.5)). Additionally, the IMT improved baroreflex sensitvity to both Tachycardic and bradycardic responses respectively (BRR Down Gain (mean): IMT=26.51(±1.7)vs15.57(±6.7), AT=13.94(±5.5)vs17.92(±1.6); BRR Up Gain (mean): IMT=17.16(±1.2)vs16.28(±1.1), AT=12.39(±5)vs12.69(±3.3)). Our results demonstrate, for the first time that in spite of AT beneficial effects on control and BP levels, inspiratory muscle training might improve importantly cardiopulmonary interaction in hypertension, with even more clear benefits on autonomic cardiovascular control.