Intolerance to physical effort

Specialty: General.

• inability to exercise
• drowning at minimum effort
• mild movement fatigue

Why it occurs

• Silent ischemic heart disease or heart failure with preserved ejection fraction (where myocardial oxygen demand exceeds supply during activity)
• Incipient restrictive or obstructive lung disease (pulmonary emphysema, idiopathic pulmonary fibrosis, or exercise-induced asthma)
• Chronic severe physical deconditioning (loss of muscle mass, reduction in stroke volume and lower mitochondrial density due to prolonged extreme sedentary lifestyle)
• Moderate to severe anemia (reduced oxygen transport capacity to peripheral tissues and myocardium)
• Morbid obesity or sarcopenic obesity (mechanical overload and ventilatory dysfunction associated with a chronic pro-inflammatory state).

Initial workup

Simple spirometry with bronchodilator test, 12-lead electrocardiogram, transthoracic echocardiogram at rest, determination of hemoglobin and hematocrit, and arterial blood gas or pulse saturometry during exercise.

Standard management

• Salbutamol — 100 to 200 mcg inhaled 15 to 30 minutes before exercise if exercise-induced bronchospasm is suspected or confirmed
• Treat underlying anemia with Ferrous Sulfate — 200 mg per day orally if there is confirmed iron deficiency
• Beta blockers in low doses (such as Carvedilol 3,125 mg every 12 hours, under strict control if intolerance is secondary to myocardial dysfunction).