Assessment of Cardiac Arrhythmias at Extreme High Altitude Using an Implantable Cardiac Monitor
2017; Lippincott Williams & Wilkins; Volume: 135; Issue: 8 Linguagem: Inglês
10.1161/circulationaha.116.026584
ISSN1524-4539
AutoresChristopher J. Boos, David Holdsworth, David Woods, John O’Hara, Naomi Brooks, Lee Macconnachie, J Bakker-Dyos, John Paisey, Adrian Mellor,
Tópico(s)Cardiovascular Effects of Exercise
ResumoHomeCirculationVol. 135, No. 8Assessment of Cardiac Arrhythmias at Extreme High Altitude Using an Implantable Cardiac Monitor Free AccessLetterPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessLetterPDF/EPUBAssessment of Cardiac Arrhythmias at Extreme High Altitude Using an Implantable Cardiac MonitorREVEAL HA Study (REVEAL High Altitude) Christopher John Boos, MBBS, MD, David A. Holdsworth, BM, BCh, MA, David Richard Woods, MB, ChB, MD, John O’Hara, BSc, MSc, PhD, Naomi Brooks, BSc, Lee Macconnachie, BSc, Josh Bakker-Dyos, BSc, MBChB, John Paisey, DM and Adrian Mellor, MB, ChB, MD Christopher John BoosChristopher John Boos From Department of Cardiology, Poole Hospital NHS Foundation Trust, UK (C.J.B., N.B., L.M.); Department of Postgraduate Medical Education, Bournemouth University, UK (C.J.B., J.P.); Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, UK (C.J.B., D.R.W., J.O. A.M.); Department of Physiology, University of Oxford, UK (D.A.H.); Defence Medical Services, Lichfield, UK (D.A.H., D.R.W., J.B.-D., A.M.); Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle, UK (D.R.W.); University of Newcastle, Newcastle upon Tyne, UK (D.R.W.); Royal Bournemouth and Christchurch Hospital, University Hospital Southampton, UK (J.P.); and James Cook University Hospital, Middlesbrough, UK (A.M.). Search for more papers by this author , David A. HoldsworthDavid A. Holdsworth From Department of Cardiology, Poole Hospital NHS Foundation Trust, UK (C.J.B., N.B., L.M.); Department of Postgraduate Medical Education, Bournemouth University, UK (C.J.B., J.P.); Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, UK (C.J.B., D.R.W., J.O. A.M.); Department of Physiology, University of Oxford, UK (D.A.H.); Defence Medical Services, Lichfield, UK (D.A.H., D.R.W., J.B.-D., A.M.); Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle, UK (D.R.W.); University of Newcastle, Newcastle upon Tyne, UK (D.R.W.); Royal Bournemouth and Christchurch Hospital, University Hospital Southampton, UK (J.P.); and James Cook University Hospital, Middlesbrough, UK (A.M.). Search for more papers by this author , David Richard WoodsDavid Richard Woods From Department of Cardiology, Poole Hospital NHS Foundation Trust, UK (C.J.B., N.B., L.M.); Department of Postgraduate Medical Education, Bournemouth University, UK (C.J.B., J.P.); Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, UK (C.J.B., D.R.W., J.O. A.M.); Department of Physiology, University of Oxford, UK (D.A.H.); Defence Medical Services, Lichfield, UK (D.A.H., D.R.W., J.B.-D., A.M.); Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle, UK (D.R.W.); University of Newcastle, Newcastle upon Tyne, UK (D.R.W.); Royal Bournemouth and Christchurch Hospital, University Hospital Southampton, UK (J.P.); and James Cook University Hospital, Middlesbrough, UK (A.M.). Search for more papers by this author , John O’HaraJohn O’Hara From Department of Cardiology, Poole Hospital NHS Foundation Trust, UK (C.J.B., N.B., L.M.); Department of Postgraduate Medical Education, Bournemouth University, UK (C.J.B., J.P.); Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, UK (C.J.B., D.R.W., J.O. A.M.); Department of Physiology, University of Oxford, UK (D.A.H.); Defence Medical Services, Lichfield, UK (D.A.H., D.R.W., J.B.-D., A.M.); Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle, UK (D.R.W.); University of Newcastle, Newcastle upon Tyne, UK (D.R.W.); Royal Bournemouth and Christchurch Hospital, University Hospital Southampton, UK (J.P.); and James Cook University Hospital, Middlesbrough, UK (A.M.). Search for more papers by this author , Naomi BrooksNaomi Brooks From Department of Cardiology, Poole Hospital NHS Foundation Trust, UK (C.J.B., N.B., L.M.); Department of Postgraduate Medical Education, Bournemouth University, UK (C.J.B., J.P.); Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, UK (C.J.B., D.R.W., J.O. A.M.); Department of Physiology, University of Oxford, UK (D.A.H.); Defence Medical Services, Lichfield, UK (D.A.H., D.R.W., J.B.-D., A.M.); Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle, UK (D.R.W.); University of Newcastle, Newcastle upon Tyne, UK (D.R.W.); Royal Bournemouth and Christchurch Hospital, University Hospital Southampton, UK (J.P.); and James Cook University Hospital, Middlesbrough, UK (A.M.). Search for more papers by this author , Lee MacconnachieLee Macconnachie From Department of Cardiology, Poole Hospital NHS Foundation Trust, UK (C.J.B., N.B., L.M.); Department of Postgraduate Medical Education, Bournemouth University, UK (C.J.B., J.P.); Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, UK (C.J.B., D.R.W., J.O. A.M.); Department of Physiology, University of Oxford, UK (D.A.H.); Defence Medical Services, Lichfield, UK (D.A.H., D.R.W., J.B.-D., A.M.); Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle, UK (D.R.W.); University of Newcastle, Newcastle upon Tyne, UK (D.R.W.); Royal Bournemouth and Christchurch Hospital, University Hospital Southampton, UK (J.P.); and James Cook University Hospital, Middlesbrough, UK (A.M.). Search for more papers by this author , Josh Bakker-DyosJosh Bakker-Dyos From Department of Cardiology, Poole Hospital NHS Foundation Trust, UK (C.J.B., N.B., L.M.); Department of Postgraduate Medical Education, Bournemouth University, UK (C.J.B., J.P.); Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, UK (C.J.B., D.R.W., J.O. A.M.); Department of Physiology, University of Oxford, UK (D.A.H.); Defence Medical Services, Lichfield, UK (D.A.H., D.R.W., J.B.-D., A.M.); Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle, UK (D.R.W.); University of Newcastle, Newcastle upon Tyne, UK (D.R.W.); Royal Bournemouth and Christchurch Hospital, University Hospital Southampton, UK (J.P.); and James Cook University Hospital, Middlesbrough, UK (A.M.). Search for more papers by this author , John PaiseyJohn Paisey From Department of Cardiology, Poole Hospital NHS Foundation Trust, UK (C.J.B., N.B., L.M.); Department of Postgraduate Medical Education, Bournemouth University, UK (C.J.B., J.P.); Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, UK (C.J.B., D.R.W., J.O. A.M.); Department of Physiology, University of Oxford, UK (D.A.H.); Defence Medical Services, Lichfield, UK (D.A.H., D.R.W., J.B.-D., A.M.); Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle, UK (D.R.W.); University of Newcastle, Newcastle upon Tyne, UK (D.R.W.); Royal Bournemouth and Christchurch Hospital, University Hospital Southampton, UK (J.P.); and James Cook University Hospital, Middlesbrough, UK (A.M.). Search for more papers by this author and Adrian MellorAdrian Mellor From Department of Cardiology, Poole Hospital NHS Foundation Trust, UK (C.J.B., N.B., L.M.); Department of Postgraduate Medical Education, Bournemouth University, UK (C.J.B., J.P.); Research Institute for Sport, Physical Activity, and Leisure, Leeds Beckett University, Leeds, UK (C.J.B., D.R.W., J.O. A.M.); Department of Physiology, University of Oxford, UK (D.A.H.); Defence Medical Services, Lichfield, UK (D.A.H., D.R.W., J.B.-D., A.M.); Northumbria and Newcastle NHS Trusts, Wansbeck General and Royal Victoria Infirmary, Newcastle, UK (D.R.W.); University of Newcastle, Newcastle upon Tyne, UK (D.R.W.); Royal Bournemouth and Christchurch Hospital, University Hospital Southampton, UK (J.P.); and James Cook University Hospital, Middlesbrough, UK (A.M.). Search for more papers by this author Originally published21 Feb 2017https://doi.org/10.1161/CIRCULATIONAHA.116.026584Circulation. 2017;135:812–814It has been suggested, although still unproven, that exposure at high altitude (HA) is proarrhythmic and could potentially contribute to an increased risk of sudden cardiac death.1,2 However, limited data are available to substantiate this claim, particularly at >5000 m. We hypothesized that extreme HA leads to an increased risk of pathological cardiac tachyarrhythmias, detected using an implantable cardiac monitor (ICM).Sixteen healthy adult white male British military servicemen underwent continuous ECG monitoring using a Reveal LINQ ICM (Medtronic Ltd) for ≥7 weeks before, during, and >8 weeks after an attempted summit of Mount Dhaulagiri (8167 m). They were required to have a normal 12-lead ECG and transthoracic echocardiogram at recruitment and were excluded if they had a history of cardiac arrhythmia. They underwent written informed consent, and the study was approved by the Ministry of Defense Research and Medical Ethics Committee. The participants flew from the United Kingdom to Kathmandu, Nepal (1400 m, days 1–2), then by road (days 3–4) to 2679 m. Thereafter, they trekked carrying moderate loads to 3720 m (day 5), 4150 m (day 7), and 5140 m, where they remained (days 11–24) for attempts on 6035- and 6800-m peaks. One subject aborted at 4100 m because of severe gastrointestinal symptoms. On day 25, 5 subjects descended, and 10 climbers remained at 4800 m for an attempted summit of Mount Dhaulagiri over days 26 to 51. The subjects were monitored wirelessly before and after departure (Medtronic MyCareLink Monitor) and during trekking using a portable Medtronic Programmer every 2 to 5 days, depending on environmental conditions.The subjects were 35.1±6.6 (24–48) years of age. Fifteen (93.8%) achieved an altitude of ≥6035 m, 6 to 6800 m, 1 to 7100 m, and 3 to 7550 m. Unfortunately, an attempted summit of Mount Dhaulagiri became impossible because of adverse weather conditions. Spo2 significantly fell at increasing HA from 96.4±1.6% at 1400 m to 93.2±2.8% at 2650 m, 88.8±3.5% at 4100 m, 80.6±5.0% at 5140 m, and 78.1±4.5% at 5340 m (ordinary analysis of covariance P 230, age in years for ≥16 beats; bradycardia as heart rate 3 sec; and atrial tachycardia/fibrillation/flutter as episodes fitting morphology detection criteria lasting >10 minutes.*Descended because of gastrointestinal illness at 4100 m.Significant pauses (>3 seconds) were identified at HA in 8 of 15 (53.3%) subjects at ≥4800 m only, with none detected in any subjects below this altitude (Fisher’s Exact Test P=0.0008). Overall, 82 pauses (3.0–7.0 seconds) were noted, which were sinus in 80 with evidence of high-grade heart block in 2 cases (mean number10.3±14.1; range 1–41) (Table). The number of pauses increased with altitude gain from 0 at 6000 m (Kruskal-Wallis Test P 6325 m at terrestrial HA. In the only previous ICM study at HA, 9 subjects were studied using first-generation reveal ICM, which lacked auto-detection capabilities, and only 2 subjects were assessed at 6325 m.1 They observed 1 short-lived episode of atrial flutter at 150/minutes (8.5 minutes) immediately after a severe exertion at 4500 m. The episode of nocturnal atrial fibrillation detected in our study would suggest vagally mediated atrial fibrillation. We would also postulate that the pauses observed in our study were likely physiological and also related to the effects of increased nocturnal vagal tone and sleep-disordered breathing, which are well recognized at HA.3,4 We believe the episode of supraventricular tachycardia relates to the combination of sympathetic activation, hypoxia, and sudden explosive exercise at HA. In addition to the factors outlined earlier, the proarrhythmic effects of HA may be partly explained by other factors, including acclimatization, changes in heart rate variability, sleep deprivation, dehydration, and anxiety.5In conclusion, HA exposure to ≥4100 m is associated with significant brady- and tachyarrhythmias in healthy adult men supporting a potential proarrhythmic risk. No link was detected between HA and sustained ventricular arrhythmias linked to an increased risk of sudden cardiac death.Sources of FundingThis study was supported by a project grant from Medtronic to fund the costs of the ICMs.DisclosuresNone.FootnotesCirculation is available at http://circ.ahajournals.org.Correspondence to: Christopher J. Boos, MBBS, MD, Department of Cardiology, Poole Hospital NHS Foundation Trust, Longfleet Rd, Poole, Dorset, UK BH15 2JB. E-mail [email protected]References1. Woods DR, Allen S, Betts TR, Gardiner D, Montgomery H, Morgan JM, Roberts PR. High altitude arrhythmias.Cardiology. 2008; 111:239–246. doi: 10.1159/000127445.CrossrefMedlineGoogle Scholar2. Burtscher M, Ponchia A. The risk of cardiovascular events during leisure time activities at altitude.Prog Cardiovasc Dis. 2010; 52:507–511. doi: 10.1016/j.pcad.2010.02.008.CrossrefMedlineGoogle Scholar3. Lombardi C, Meriggi P, Agostoni P, Faini A, Bilo G, Revera M, Caldara G, Di Rienzo M, Castiglioni P, Maurizio B, Gregorini F, Mancia G, Parati G; HIGHCARE investigators. High-altitude hypoxia and periodic breathing during sleep: gender-related differences.J Sleep Res. 2013; 22:322–330. doi: 10.1111/jsr.12012.CrossrefMedlineGoogle Scholar4. Nemirovsky D, Hutter R, Gomes JA. The electrical substrate of vagal atrial fibrillation as assessed by the signal-averaged electrocardiogram of the P wave.Pacing Clin Electrophysiol. 2008; 31:308–313. doi: 10.1111/j.1540-8159.2008.00990.x.CrossrefMedlineGoogle Scholar5. Hansen J, Sander M. Sympathetic neural overactivity in healthy humans after prolonged exposure to hypobaric hypoxia.J Physiol2003; 546:921–929.CrossrefMedlineGoogle Scholar Previous Back to top Next FiguresReferencesRelatedDetailsCited By Berthelsen L, van Diepen S, Steele A, Vanden Berg E, Bird J, Thrall S, Skalk A, Byman B, Pentz B, Wilson R, Jendzjowsky N, Day T and Steinback C (2021) Duration at high altitude influences the onset of arrhythmogenesis during apnea, European Journal of Applied Physiology, 10.1007/s00421-021-04842-x, 122:2, (475-487), Online publication date: 1-Feb-2022. Parsons I, Nicol E, Holdsworth D, Guettler N, Rienks R, Davos C, Halle M and Parati G (2021) Cardiovascular risk in high-hazard occupations: the role of occupational cardiology, European Journal of Preventive Cardiology, 10.1093/eurjpc/zwab202, 29:4, (702-713), Online publication date: 30-Mar-2022. 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Smith M, Withnall R, Anastasova S, Gil-Rosa B, Blackadder-Coward J and Taylor N (2021) Developing a multimodal biosensor for remote physiological monitoring, BMJ Military Health, 10.1136/bmjmilitary-2020-001629, (bmjmilitary-2020-001629) He C, Xiang H, Liu C, Yu S, Yang J, Ding X, Bian S, Zhang J, Tan H, Jin J, Hu M, Zhang C, Rao R, Huang L and Kirchmair R (2021) Assessment of right atrial dyssynchrony by 2D speckle-tracking in healthy young men following high altitude exposure at 4100 m, PLOS ONE, 10.1371/journal.pone.0247107, 16:2, (e0247107) Busch S, van Diepen S, Steele A, Meah V, Simpson L, Figueroa-Mujíca R, Vizcardo-Galindo G, Villafuerte F, Tymko M, Ainslie P, Moore J, Stembridge M and Steinback C (2020) Global REACH: Assessment of Brady-Arrhythmias in Andeans and Lowlanders During Apnea at 4330 m, Frontiers in Physiology, 10.3389/fphys.2019.01603, 10 Boos C, Bye K, Sevier L, Bakker-Dyos J, Woods D, Sullivan M, Quinlan T and Mellor A (2018) High Altitude Affects Nocturnal Non-linear Heart Rate Variability: PATCH-HA Study, Frontiers in Physiology, 10.3389/fphys.2018.00390, 9 February 21, 2017Vol 135, Issue 8 Advertisement Article InformationMetrics © 2017 American Heart Association, Inc.https://doi.org/10.1161/CIRCULATIONAHA.116.026584PMID: 28223328 Originally publishedFebruary 21, 2017 Keywordsarrhythmiasimplantable cardiac monitorhigh altitudePDF download Advertisement SubjectsArrhythmias
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