Background: Valvular Heart Disease (VHD), particularly Rheumatic Heart Disease (RHD), is a major health burden in Indonesia, often requiring heart valve surgery. Post-operative respiratory muscle dysfunction and reduced functional capacity hinder recovery. Inspiratory Muscle Training (IMT) is a non-invasive intervention that improves respiratory muscle strength and functional outcomes. This scoping review evaluates the role of IMT in enhancing functional capacity among patients after heart valve surgery.Methods: A systematic search of PubMed and Scopus identified Randomized Controlled Trials (RCTs) and cohort studies involving adult patients who underwent IMT interventions after heart valve surgery. The search strategy combined controlled vocabulary (Medical Subject Headings [MeSH]) Key terms included: (“heart valve surgery” OR “valve replacement” OR “valvular heart disease”) AND (“inspiratory muscle training” OR “respiratory muscle training”) AND (“functional capacity” OR “exercise capacity” OR “respiratory muscle strength” OR “pulmonary function”). Outcomes included functional capacity, respiratory muscle strength, pulmonary function, Post-operative Pulmonary Complications (PPCs), and hospital Length of Stay (LOS). Data were synthesized narratively.Results: Four RCTs (273 patients) showed IMT significantly improved Maximal Inspiratory Pressure (MIP), Six-Minute Walk Distance (6MWD), and pulmonary function [Forced Vital Capacity (FVC), Forced Expiratory Volume in 1 second (FEV₁)]. Interventions of 4–12 weeks reduced PPCs and LOS. Optimal benefits were observed with 8–12-week protocols.Conclusion: IMT enhances functional capacity, respiratory muscle strength, and pulmonary function post-heart valve surgery, with the potential to reduce complications and costs. Its integration into rehabilitation programs is recommended, particularly in regions with high RHD prevalence, such as Indonesia. Further studies should standardize protocols and assess long-term outcomes.