A patient came with dyspnea, elevated JVP and edema in the feet. Lungs are clear. There is a parasternal heave and S2 is palpable in the pulmonary area. Which one of the following is LEAST helpful in determining etiology?

* The findings of dyspnea, elevated JVP and pedal oedema are suggestive of right sided CHF * Parasternal heave and palpable S2 indicates pulmonary aery hypeension * This also explains why lungs are clear since pulmonary oedema is absent in PAH * Reduced RV compliance in RVH leads to elevated JVP and oedema in feet * The reason for dyspnea is less pulmonary flow due to PAH. Echo for mitral stenosis Useful for diagnosis as PAH is seen in long standing MS ELISA For HIV Useful for diagnosis of Group 1 PAH Urine and stool for Schistosoma Useful for diagnosis of Group 1 PAH WHO classification of PAH Group 1 Idiopathic PAH HIV Poal Hypeension (Schistosomiasis) Drugs Connective tissue disorders Pulmonary veno-occlusive disease Group 2 Pulmonary aery hypeension due to left hea disease Group 3 PAH due to lung disease like COPD, interstitial lung disease Group 4 PAH due to secondary thromboembolism with occlusion of proximal or distal pulmonary aeries Group 5 PAH due to Hematological disorders: Myeloproliferative disorders Systemic disorders: Sarcoidosis, Langerhans cell histiocytosis Metabolic disorders: glycogen storage disorders Miscellaneous: Tumor embolization