Exertional Desaturation in Patients with Asthma and HFpEF

Primary Differential Diagnoses

The American College of Cardiology recommends considering valvular heart disease, particularly aortic stenosis or mitral regurgitation, as a potential cause of exertional desaturation in patients with HFpEF 2, 3
The American College of Cardiology suggests that atrial fibrillation with inadequate rate control can precipitate symptoms in patients with HFpEF 3, 5
The American College of Cardiology notes that infiltrative cardiomyopathy, such as cardiac amyloidosis, should be considered in patients with HFpEF and increased LV wall thickness on echocardiography 2, 3
Asthma exacerbation or poor control can cause exertional bronchoconstriction and desaturation in patients with asthma 1, 6
Pulmonary embolism should be considered in any patient with new or worsening dyspnea, although most minor PEs do not cause hypoxemia 6

The American Thoracic Society recommends measuring vital signs with orthostatic measurements, including respiratory rate, heart rate, blood pressure, and temperature, to detect hypoxemia 1, 6, 7
Pulse oximetry at rest and with ambulation is essential to document oxygen saturation during activity 1, 6, 7
Arterial blood gas analysis is necessary to exclude hypercapnia and assess acid-base status, particularly in patients with potential respiratory failure 1, 7, 8
The American College of Cardiology recommends echocardiography with Doppler to assess for valvular disease, right ventricular function, and estimated pulmonary artery systolic pressure (PASP) 2, 3, 4

The American College of Cardiology emphasizes the importance of systematic evaluation for noncardiac mimics (kidney disease, liver disease, chronic venous insufficiency) and cardiac mimics (infiltrative cardiomyopathy, valvular disease, pericardial disease) in patients with dyspnea and preserved EF 2, 3, 5
The American Thoracic Society recommends targeting oxygen saturation of 94-98% unless the patient has risk factors for hypercapnic respiratory failure, in which case the target should be 88-92% 1, 6, 7, 8