The Vicious Cycle of Dyspnea in Patients with Heart Failure - ISMBE - Biomedical Engineering, International Convention Center Haifa 22.2.2018

אנה פיינגרש ¹ Shmuel Rispler ² Eugenia Nikolsky ² Yuval Cohen ² Arthur Kerner ² Sergey Yalonetsky ² Amnon Eitan ² Ariel Roguin ² Amir Landesberg ¹

¹Faculty of Biomedical Engineering, Technion-Israel Institute of Technology
²Cardiology, Rambam Health Care Campus

Heart failure (HF) is characterized by frequent decompensation phases. We hypothesized that: 1) decompensation results in dyspnea due to an increase in the respiratory effort, 2) respiratory effort causes further deterioration of HF. The study enrolled patients undergoing right heart catheterization. Pulmonary wedge pressure was separated into: respiratory wave (P_RESP) and capillary transmural pressure (P_CT). Remarkably, P_RESP values were very high - up to 43 mmHg in HF patients, with high correlation between P_RESP (surrogate of dyspnea) and P_CT (r = 0.76). This raises the question of cause/consequence relationships. An increase in the wedge pressure intensifies the required respiratory work, since it elevates pulmonary capillary pressure, resulting in decreased lung compliance. On the other hand, intensified respiratory effort and larger P_RESP increase the apparent LV afterload and are associated with more pronounced RA filling and lower LA filling that contribute to further lung congestion. The latter was indicated by the opposite modulation of the left and right atrial V-waves by respiration, which increased with the elevation of P_RESP. The respiratory effort plays a pivot role in the cardiac decompensation vicious cycles.