Objectives: Right ventricle (RV) function is a recognized independent determinant of morbidity and mortality in heart failure (HF), encompassing various etiologies such as congenital heart disease, pulmonary hypertension, and coronary artery disease. The prognostic significance of RV dysfunction in different HF subtypes – HF with preserved ejection fraction (HFpEF), mid‑range EF (HFmrEF), and reduced EF (HFrEF) – continues to gain attention. This study aimed to assess RV dysfunction, quantified by global longitudinal strain (RV GLS), as an early and sensitive predictor of outcomes in HF patients categorized by EF. Materials and Methods: A prospective study of 100 HF patients categorized into HFpEF (left ventricular EF [LVEF] >50%, n = 16), HFmrEF (LVEF 40%–50%, n = 47), and HFrEF (LVEF < 40%, n = 37). Echocardiographic assessments, including RV GLS, were performed using a standardized protocol on the Philips EPIC 7C system. RV GLS was analyzed as a sensitive marker for poor outcomes, defined by major adverse cardiac events (MACE) and worsening functional status. Results: RV GLS demonstrated significant variation among the groups. Patients in Group C (HFrEF, LVEF < 40%) exhibited markedly lower RV GLS compared to Group A (HFpEF, LVEF > 50%) (−13.5 ± 5.24 vs. −16.8 ± 4.21; P = 0.006). In addition, a significant difference was noted between Group C and Group B (HFmrEF, LVEF 40‑50%) (−13.5 ± 5.24 vs. −14.6 ± 4.15; P = 0.047). The predictive value of RV GLS for poor outcomes in HF patients was supported by a sensitivity of 75% and specificity of 69.12%, with a cutoff threshold of − 14.7%. Conclusions: RV GLS serves as a dependable marker for predicting poor outcomes in HF patients, with a defined cutoff value of –14.7%. This metric holds substantial clinical promise for effective risk stratification and timely intervention, demonstrating a sensitivity of 75% and a specificity of 69.12%.