A woman with worsening dyspnea and chest pressure is suspected to have PAH. What characteristic symptom aligns with WHO FC IV classification?

In the context of pulmonary arterial hypertension (PAH), the World Health Organization (WHO) Functional Classification categorizes patients based on the severity of their symptoms and the impact on daily activities. WHO Functional Class IV is characterized by symptoms that significantly limit daily activities, including experiencing dyspnea even at rest.

The characteristic symptom that aligns with WHO FC IV classification is feeling breathless at rest. This indicates a severely compromised functional status and suggests advanced disease progression, where patients experience significant limitations due to symptoms, even in the absence of exertion. This level of dyspnea reflects the critical nature of their condition and the urgent need for medical intervention.

Other classifications, like light exertion symptoms or only experiencing issues while walking, reflect less severe impairment, which would not be consistent with WHO FC IV. Therefore, identifying breathlessness at rest as a symptom indicates a more severe manifestation of PAH, aligning it correctly with the WHO FC IV classification.