Erevik Christine Bjørkvik, Kleiven Øyunn, Frøysa Vidar, Bjørkavoll-Bergseth Magnus, Chivulescu Monica, Klæboe Lars Gunnar, Dejgaard Lars, Auestad Bjørn, Skadberg Øyvind, Melberg Tor, Urheim Stig, Haugaa Kristina, Edvardsen Thor, Ørn Stein
Department of Cardiology, Stavanger University Hospital, Stavanger, Norway.
ProCardio Center for Innovation, Department of Cardiology, Oslo University Hospital, Rikshospitalet, Oslo, Norway.
Front Cardiovasc Med. 2023 Jan 11;9:1081664. doi: 10.3389/fcvm.2022.1081664. eCollection 2022.
The effect of prolonged, high-intensity endurance exercise on myocardial function is unclear. This study aimed to determine the left ventricular (LV) response to increased exercise duration and intensity using novel echocardiographic tools to assess myocardial work and fatigue.
LV function was assessed by echocardiography before, immediately, and 24 h after a cardiopulmonary exercise test (CPET) and a 91-km mountain bike leisure race. Cardiac Troponin I (cTnI) was used to assess myocyte stress.
59 healthy recreational athletes, 52 (43-59) years of age, 73% males, were included. The race was longer and of higher intensity generating higher cTnI levels compared with the CPET ( < 0.0001): Race/CPET: exercise duration: 230 (210, 245)/43 (40, 45) minutes, mean heart rate: 154 ± 10/132 ± 12 bpm, max cTnI: 77 (37, 128)/12 (7, 23) ng/L. Stroke volume and cardiac output were higher after the race than CPET ( < 0.005). The two exercises did not differ in post-exercise changes in LV ejection fraction (LVEF) or global longitudinal strain (GLS). There was an increase in global wasted work ( = 0.001) following the race and a persistent reduction in global constructive work 24 h after exercise ( = 0.003).
Increased exercise intensity and duration were associated with increased myocardial wasted work post-exercise, without alterations in LVEF and GLS from baseline values. These findings suggest that markers of myocardial inefficiency may precede reduction in global LV function as markers of myocardial fatigue.
长时间、高强度耐力运动对心肌功能的影响尚不清楚。本研究旨在使用新型超声心动图工具评估心肌做功和疲劳，以确定左心室（LV）对运动持续时间和强度增加的反应。
在心肺运动试验（CPET）和91公里山地自行车休闲赛后，立即以及赛后24小时通过超声心动图评估左心室功能。使用心肌肌钙蛋白I（cTnI）评估心肌细胞应激。
纳入了59名健康的休闲运动员，年龄52（43 - 59）岁，男性占73%。与CPET相比，比赛时间更长、强度更高，导致cTnI水平更高（<0.0001）：比赛/CPET：运动持续时间：230（210，245）/43（40，45）分钟，平均心率：154±10/132±12次/分钟，最大cTnI：77（37，128）/12（7，23）纳克/升。比赛后每搏输出量和心输出量高于CPET（<0.005）。两种运动在运动后左心室射血分数（LVEF）或整体纵向应变（GLS）的变化方面无差异。比赛后整体无用功增加（=0.001），运动后24小时整体有用功持续减少（=0.003）。
运动强度和持续时间增加与运动后心肌无用功增加相关，LVEF和GLS与基线值相比无变化。这些发现表明，心肌效率低下的标志物可能先于左心室整体功能降低，作为心肌疲劳的标志物。
