TY - JOUR T1 - Quadriceps muscle fibre dysfunction in patients with pulmonary arterial hypertension JF - European Respiratory Journal JO - Eur Respir J SP - 1737 LP - 1740 DO - 10.1183/09031936.00205114 VL - 45 IS - 6 AU - Emmy Manders AU - Gerrina Ruiter AU - Harm-Jan Bogaard AU - Ger J.M. Stienen AU - Anton Vonk-Noordegraaf AU - Frances S. de Man AU - Coen A.C. Ottenheijm Y1 - 2015/06/01 UR - http://erj.ersjournals.com/content/45/6/1737.abstract N2 - Despite improvements in disease targeted therapies, pulmonary arterial hypertension (PAH) is a progressive disease and PAH patients remain symptomatic [1]. Exercise intolerance is one of the main symptoms, which limit PAH patients in their daily life activities. Reduced exercise capacity is generally attributed to right ventricular dysfunction [1]. However, as with other cardiac and pulmonary diseases, PAH patients develop respiratory [2] and peripheral muscle [3, 4] weakness, which might also contribute to exercise intolerance. Indeed, exercise training improves exercise capacity in PAH patients and maximal oxygen consumption of PAH patients correlates with the functional decline of peripheral muscle strength [5, 6]. The underlying cause of the reduction in muscle strength is unclear. Some studies have reported muscle fibre atrophy and a shift towards more fast-twitch fatigable fibres in skeletal muscles of PAH patients [3, 7]; however, these are not consistent findings [4, 8]. Peripheral muscle weakness in PAH patients is at least partly caused by sarcomeric dysfunction http://ow.ly/J8LuE ER -