The travelling options currently available allow an increasingly large number of individuals, including sedentary people, the elderly and diseased patients, to reach high altitude (HA) locations, defined as locations higher than 2500 m above sea level (asl),1S i.e. the altitude above which many of the physiological responses that represent challenges for the human body start developing. Physiological acclimatization mechanisms impose an increased workload on the cardiovascular system, but the actual risk of adverse cardiovascular events associated with HA exposure is still a debated issue. The aim of this article is to review the available evidence on the effects of HA in cardiovascular patients and to address their risk of developing clinically relevant events. This was done through multiple Medline searches on the PubMed database, with the main aim of promoting a generally safe access to mountains. Searched terms included a combination of either ‘high altitude’ or ‘hypobaric hypoxia’ plus each of the following: ‘physiology’, ‘maladaption’, ‘cardiovascular response’, ‘systemic hypertension’, ‘pulmonary hypertension’, ‘ischaemic heart disease’, ‘cardiac revascularisation’, ‘heart failure’, ‘congenital heart disease’, ‘arrhythmias’, ‘implantable cardiac devices’, ‘stroke’, ‘cerebral haemorrhage’, ‘exercise’, ‘sleep apnea’. Compared with a previous review article on this topic,2S we now include the most recent data on hypoxia-induced changes in left ventricular (LV) systolic and diastolic function, lung function and ventilation control, blood coagulation, and on the effects of pharmacological interventions. We also offer an update on the clinical and pathophysiological findings related to the exposure to altitude of patients with pre-existing cardiovascular conditions (ischaemic heart disease, heart failure, and arterial and pulmonary hypertension).</p
