Koronare Herzkrankheit – Höhenmedizinische Beratung

Höhenaufenthalte von Personen mit koronarer Herzkrankheit sind von einer gewissen Unsicherheit begleitet, weil entsprechende Studien fehlen, die eine sichere Beurteilung der Höhentauglichkeit dieser Patienten zulassen. Aus diesem Grund haben wir die verfügbare Literatur evaluiert und versucht, daraus Empfehlungen für sichere Höhenaufenthalte bei Patienten mit koronarer Herzkrankheit abzuleiten. In der Höhe steht dem verminderten Sauerstoffangebot ein erhöhter myokardialer Sauerstoffbedarf gegenüber. Bei atherosklerotisch veränderten Koronararterien kommt möglicherweise noch eine paradoxe hypoxieinduzierte Vasokonstriktion hinzu. Offensichtlich werden dadurch aber relevante myokardiale Ischämien nicht vermehrt ausgelöst. So scheint das kardiale Risiko allein durch die höhenbedingte Hypoxie bis 3500 m bei stabiler koronarer Herzkrankheit und normaler Leistungsfähigkeit kaum erhöht zu sein. Wegen des deutlichen Rückgangs der Leistungsfähigkeit über 3500 m sollte für solche Aufenthalte zusätzlich eine gute linksventrikuläre Pumpfunktion und eine deutlich überdurchschnittliche Leistungsfähigkeit gefordert werden. In der Regel sollte Patienten mit koronarer Herzkrankheit von Aufenthalten über 4500 m abgeraten werden, weil hier bereits in Ruhe eine deutlich Hypoxämie besteht. Patienten mit instabiler koronarer Herzkrankheit sollten in keinem Fall in die Höhe gehen. Generell müssen die Umstände des Höhenaufenthalts berücksichtigt werden, insbesondere auch die oft schlechte medizinische Infrastruktur in den Hochgebirgsregionen. Im Zweifel steht immer die Sicherheit des Patienten im Vordergrund

The number of patients with coronary heart disease (CHD) travelling to high altitude increased over the past years. There is, however, some uncertainty about the risk for those patients, mainly due to the relatively poor quality of data on CHD at high altitude. In this paper we, therefore, tried to derive rea-sonable recommendations from the current literature for a safe stay at high altitude in CHD patients. At high altitude, oxygen availability is reduced, myocardial oxygen demand is increased and there is some evidence of paradoxical hypoxia-induced vasoconstriction in atherosclerotic-altered coronary arteries due to endothelial dysfunction. Clinical data, however, suggest that this does not cause relevant myocardial ischemia in stable CHD with normal exercise capacity up to 3500 m. For a safe stay above 3500 m, a preserved left-ventricular function and an exercise capacity above normal are additionally required. Due to severe hypoxia at altitudes above 4500 m, CHD patients should avoid to travel to these elevations. Patients with instable CHD generally should not go to high altitudes. In case of doubt, it is always better to err on the side of caution. Furthermore, risk assessment of CHD patients at altitude should always consider a possible absence of medical support and that cardiovascular events with good prognosis at home may turn into disaster.

Key words

atherosclerosis - coronary heart disease - coronary artery disease - high altitude - hypoxia

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