Pathophysiology of Muscle in Pulmonary and Cardiovascular Conditions

Abstract

Purpose: To provide an overview of skeletal muscle pathophysiology in pulmonary and cardiovascular conditions commonly managed by physical therapists. Summary of Key Points: This review describes the muscle pathophysiology associated with congestive heart failure, chronic obstructive pulmonary disease, interstitial lung disease, cystic fibrosis, intensive care unit–acquired weakness, immobilization, and aging. Causes of poor muscle performance are multifactorial; disease-specific and generic factors can contribute to the etiology. The time course of deterioration of peripheral and ventilatory muscle may each follow a distinctive course dependent on disease severity, its progression, and other influencing factors. Generic factors that are common in many respiratory and cardiovascular conditions are systemic inflammation and oxidative stress leading to peripheral and ventilatory muscle dysfunction that is accentuated by reduced physical activity. Loss of muscle function associated with aging is also reflected in both peripheral and ventilatory muscles. Evidence of how exercise training can counter the deleterious effects of disease on physical function is outlined. Statement of Conclusions: Patients with pulmonary and cardiovascular conditions may experience atrophy and weakness due to macroscopic, cellular, and metabolic alterations. Physical therapy interventions to improve muscle function need to consider the potential reversibility and related time course of the underlying pathophysiology of muscle dysfunction.