Glenn M Stewart1, Courtney M Wheatley-Guy2, Norman R Morris3,4,5, Kirsten E Coffman2, Jan Stepanek6, Alex R Carlson2, Amine Issa2, Michael A Schmidt7,8, Bruce D Johnson2. 1. Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Scottsdale, MN, 55905, USA. stewart.glenn@mayo.edu. 2. Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Scottsdale, MN, 55905, USA. 3. School of Allied Health Sciences, Griffith University, Gold Coast, Australia. 4. Allied Health Research Collaborative, Metro North Hospital and Health Service, The Prince Charles Hospital, Brisbane, Australia. 5. Hopkins Centre and Menzies Health Institute, Griffith University, Gold Coast, Australia. 6. Aerospace Medicine Program, Mayo Clinic, Scottsdale, USA. 7. Advanced Pattern Analysis & Countermeasures Group, Boulder, USA. 8. Sovaris Aerospace, Boulder, USA.
Abstract
INTRODUCTION: High-altitude ascent induces left (LV) and right (RV) ventricular adaptations secondary to hypoxia-related hemodynamic and myocardial alterations. Since cardiopulmonary decrements observed with aging (e.g., decreased LV compliance and increased pulmonary vascular resistance) may limit cardiac plasticity, this study examined myocardial adaptability throughout an 11 day sojourn to 5893 m in young and older-aged trekkers. METHODS AND RESULTS: Echocardiography was performed on 14 young (8 men; 32 ± 5 years) and 13 older-aged (8 men; 59 ± 5 years) subjects on non-trekking days (Day 0: 880 m; Day 3: 3100 m; Day 8: 4800 m; Day 12/post-climb: 880 m). RV systolic pressure (mmHg) was systematically higher in older-aged subjects (p < 0.01) with similar progressive increases observed during ascent for young and older subjects, respectively (Day 0: 18 ± 1 vs 20 ± 2; Day 3: 25 ± 2 vs 29 ± 3; Day 8: 30 ± 2 vs 35 ± 2). Estimates of LV filling pressure (E/E') were systematically higher in older subjects (p < 0.01) with similar progressive decreases observed during ascent for young and older-aged subjects, respectively (Day 0: 5.6 ± 0.3 vs 6.7 ± 0.5; Day 3: 5.1 ± 0.2 vs 6.1 ± 0.3; Day 8: 4.7 ± 0.3 vs 5.4 ± 0.3). Overall, RV end-diastolic and end-systolic area increased at altitude (p < 0.01), while LV end-diastolic and end-systolic volume decreased (p < 0.01). However, all RV and LV morphological measures were similar on Day 3 and Day 8 (p > 0.05), and returned to baseline post-climb (p > 0.05). Excluding mild LV dilatation in some older-aged trekkers on Day 8/Day 12 (p < 0.01), altitude-induced morphological and functional adaptations were similar for all trekkers (p > 0.05). CONCLUSION: Altitude-induced myocardial adaptations are chamber specific, secondary to RV and LV hemodynamic alterations. Despite progressive hemodynamic alterations during ascent, morphological and functional cardiac perturbations plateaued, suggesting rapid myocardial adaptation which was mostly comparable in young and older-aged individuals.
INTRODUCTION: High-altitude ascent induces left (LV) and right (RV) ventricular adaptations secondary to hypoxia-related hemodynamic and myocardial alterations. Since cardiopulmonary decrements observed with aging (e.g., decreased LV compliance and increased pulmonary vascular resistance) may limit cardiac plasticity, this study examined myocardial adaptability throughout an 11 day sojourn to 5893 m in young and older-aged trekkers. METHODS AND RESULTS: Echocardiography was performed on 14 young (8 men; 32 ± 5 years) and 13 older-aged (8 men; 59 ± 5 years) subjects on non-trekking days (Day 0: 880 m; Day 3: 3100 m; Day 8: 4800 m; Day 12/post-climb: 880 m). RV systolic pressure (mmHg) was systematically higher in older-aged subjects (p < 0.01) with similar progressive increases observed during ascent for young and older subjects, respectively (Day 0: 18 ± 1 vs 20 ± 2; Day 3: 25 ± 2 vs 29 ± 3; Day 8: 30 ± 2 vs 35 ± 2). Estimates of LV filling pressure (E/E') were systematically higher in older subjects (p < 0.01) with similar progressive decreases observed during ascent for young and older-aged subjects, respectively (Day 0: 5.6 ± 0.3 vs 6.7 ± 0.5; Day 3: 5.1 ± 0.2 vs 6.1 ± 0.3; Day 8: 4.7 ± 0.3 vs 5.4 ± 0.3). Overall, RV end-diastolic and end-systolic area increased at altitude (p < 0.01), while LV end-diastolic and end-systolic volume decreased (p < 0.01). However, all RV and LV morphological measures were similar on Day 3 and Day 8 (p > 0.05), and returned to baseline post-climb (p > 0.05). Excluding mild LV dilatation in some older-aged trekkers on Day 8/Day 12 (p < 0.01), altitude-induced morphological and functional adaptations were similar for all trekkers (p > 0.05). CONCLUSION: Altitude-induced myocardial adaptations are chamber specific, secondary to RV and LV hemodynamic alterations. Despite progressive hemodynamic alterations during ascent, morphological and functional cardiac perturbations plateaued, suggesting rapid myocardial adaptation which was mostly comparable in young and older-aged individuals.
Entities:
Keywords:
Aging; Cardiac function; Echocardiography; Expedition; High altitude; Trekking
Authors: Deborah Riebe; Barry A Franklin; Paul D Thompson; Carol Ewing Garber; Geoffrey P Whitfield; Meir Magal; Linda S Pescatello Journal: Med Sci Sports Exerc Date: 2015-11 Impact factor: 5.411
Authors: Mike Stembridge; Philip N Ainslie; Michael G Hughes; Eric J Stöhr; James D Cotter; Amanda Q X Nio; Rob Shave Journal: J Appl Physiol (1985) Date: 2014-05-29
Authors: Jesper Kjaergaard; Eric M Snyder; Christian Hassager; Thomas P Olson; Jae K Oh; Bruce D Johnson; Robert P Frantz Journal: Eur J Appl Physiol Date: 2007-10-02 Impact factor: 3.078