Which test helps distinguish HF from primary pulmonary disease in dyspnea assessment?

• A. BNP testing
• B. Chest X-ray
• C. ECG
• D. Pulmonary function tests

Answer: (A)

BNP testing helps distinguish heart failure from primary pulmonary disease when evaluating dyspnea. BNP is released by ventricular cells in response to stretch from elevated filling pressures; in heart failure these pressures are high, so BNP levels rise. A higher BNP supports heart failure as the cause of dyspnea rather than a lung condition, guiding appropriate treatment like diuresis and fluid management. Normal or low BNP makes heart failure less likely, though results should be interpreted with the overall clinical picture. Other tests can help but aren’t as definitive for this distinction: Chest X-ray may show edema or an enlarged heart, but those findings aren’t exclusive to heart failure; ECG can show rhythm issues or ischemia but doesn’t confirm HF; pulmonary function tests focus on lung mechanics and diseases, not cardiac function.