Background: Chronic obstructive pulmonary disease (COPD) is associated with cardiovascular disease. We investigated whether sleeping at altitude increases nocturnal heart rate (HR) and other markers of cardiovascular risk or arrhythmias in lowlanders with COPD and whether this can be prevented by nocturnal oxygen therapy (NOT). Methods: Twenty-four COPD patients. with median age of 66... https://www.roneverhart.com/SAAB-9-3-I-98-02-Frontlykt-Hoyre/