Kandil, H. I., el ghany, M. M. A., Risk, H., Darwish, R. M., Osama, D., & Ibrahim, M. A. (2018). Valsalva Maneuver in diastolic heart failure, diastolic dysfunction and systolic heart failure clinically BNP and echocardiography. Journal of Cardiovascular Medicine and Cardiology, 5(4), 048–052. https://doi.org/10.17352/2455-2976.000071