Fig. 2From: Primary mitochondrial disease as a rare cause of unclear breathlessness and distinctive performance degradation – a case reportCardiopulmonary exercise testing combined with right heart catheterization shows a rapid increase in lactate level, hyperdynamic circulatory adaptation, and low arteriovenous oxygen difference, consistent with the presence of a mitochondrial disorder. Δ = change; CO = cardiac output; VO2 = oxygen uptakeBack to article page