Diaphragmatic Function in Cardiovascular Disease: JACC Review Topic of the Week.

In addition to the diaphragm's role as the primary respiratory muscle, it also plays an under-recognized role in cardiac function. It serves as a pump facilitating venous and lymph return, modulating left ventricular afterload hemodynamics and pericardial pressures, as well as regulating autonomic tone. Heart failure (HF) is associated with diaphragmatic changes (ie, muscle fiber atrophy and weakness, increased ratio of type I to type II muscle fibers, and altered muscle metaboreflex) that lead to diaphragmatic dysfunction with subsequent symptomatic manifestations of HF. Herein, it is proposed that targeting the diaphragm in patients with HF via inspiratory muscle training or device-based stimulation can provide a novel treatment pathway for HF. Reviewed are several potential mechanisms through which therapies targeting the diaphragm can be beneficial in HF (ie, improving preload reserve, atrial and ventricular synchrony, and metaboreflex activity; reducing pericardial restraint; and restoring diaphragm strength).
Competing Interests: Funding Support and Author Disclosures Dr Goldberg has served as a consultant to Viscardia. Dr Tedford has consulting relationships with Medtronic, Abbott, Aria CV Inc, Acceleron, CareDx, Itamar, Edwards LifeSciences, Eidos Therapeutics, Lexicon Pharmaceuticals, Gradient, and United Therapeutics; has served on a steering committee for Acceleron and Abbott; has served on a research advisory board for Abiomed; and has performed hemodynamic core lab work for Actelion and Merck. Dr Mirro is the chief medical officer of Viscardia. Dr Fudim has received support from the National Heart, Lung, and Blood Institute (K23HL151744), the American Heart Association (20IPA35310955), Mario Family Award, Duke Chair’s Award, Translating Duke Health Award, Bayer, Bodyport, and BTG Specialty Pharmaceuticals; and has received consulting fees from Abbott, AxonTherapies, Bodyguide, Bodyport, Boston Scientific, CVRx, Daxor, Edwards LifeSciences, Feldschuh Foundation, Fire1, Gradient, Inovise Medical, Intershunt, NXT Biomedical, Pharmacosmos, PreHealth, Splendo, Vironix, Viscardia, and Zoll. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
(Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)