Diagnosis and Assessment of Disease Severity
Assessment of Disease Severity ÎSymptomatic classification correlates with survival.
ÎThe World Health Organization functional assessment classification is a modification of the NYHA classification that emphasizes the occurrence of syncope:
> Class I: Patients with PH but without resulting limitation of physical activity. Ordinary physical activity does not cause undue dyspnea or fatigue, chest pain, or near syncope.
> Class II: Patients with PH resulting in slight limitation of physical activity. They are comfortable at rest. Ordinary physical activity causes undue dyspnea or fatigue, chest pain, or near syncope.
> Class III: Patients with PH resulting in marked limitation of physical activity. They are comfortable at rest. Less that ordinary activity causes undue dyspnea or fatigue, chest pain, or near syncope.
> Class IV: Patients with PH with syncope or inability to carry out any physical activity without symptoms. These patients manifest signs of right-heart failure. Dyspnea and/or fatigue may even be present at rest. Discomfort is increased by any physical activity.
ÎSix minute walk distance (6MWD) is the most common exercise test for assessing PAH.
> Originally used as an objective measure of exercise capacity in patients with heart failure
> Used as a primary endpoint in many or most clinical trials of PAH > Predictive of survival in patients with IPAH
ÎSymptoms rated by WHO classification and 6MWD, and in some cases hemodynamics, are main methods for evaluating response to therapy.
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