Background/Objectives: Heart failure with preserved ejection fraction (HFpEF) accounts for nearly half of all heart failure cases and remains challenging to diagnose and manage due to its complex, multifactorial nature. Increasing evidence highlights the significance of arterial stiffness, assessed by pulse wave velocity (PWV), and autonomic dysfunction, reflected by impaired heart rate recovery (HRR) after exercise, as relevant markers in HFpEF. This review aims to synthesize current knowledge on the diagnostic and prognostic value of PWV and HRR in HFpEF. Methods: A narrative literature review was conducted using PubMed to identify studies published between 2009 and 2025 that investigated PWV and HRR in patients with HFpEF or populations at risk. Included studies ranged from invasive hemodynamic measurements and cardiopulmonary exercise tests to large cohort analyses such as IDENTIFY-HF and MESA. Key findings were summarized in comparative tables. Results: Patients with HFpEF consistently show higher PWV than age-matched controls, supporting the concept of HFpEF as a systemic vascular disorder. Elevated PWV has been linked to increased risk of HFpEF onset and poorer outcomes. Likewise, blunted HRR indicates autonomic imbalance and is strongly associated with higher morbidity and mortality. Interventions including structured exercise training and optimized risk factor management may help improve PWV and HRR. Conclusions: PWV and HRR offer valuable, complementary insights for risk stratification and individualized care in HFpEF. Further research should focus on integrating these parameters into diagnostic algorithms and evaluating targeted therapies that address vascular stiffness and autonomic dysfunction.

Background: Mitral annular plane systolic excursion (MAPSE) is a simple and widely used M-mode echocardiographic marker of left-ventricular longitudinal function that correlates well with left ventricular ejection fraction (LVEF). Conventional chronic right ventricle (RV) pacing is associated with left ventricle (LV) dysfunction, inducing heart failure (HF) and leading to the development of pacing-induced cardiomyopathy (PiCM). The aim of this study is to ascertain the clinical usefulness of MAPSE in the assessment of LV function in patients with permanent RV pacing. Methods: We performed a cross-sectional association analysis, enrolling consecutive patients with pacemakers and chronic RV pacing burdens over 20% (Vp > 20%) from 2021 to 2024. All patients were assessed by standard transthoracic echocardiography (TTE) with LVEF and MAPSE among other parameters being assessed. We performed a correlation test using linear regression and plotted an ROC curve. Results: 409 patients (mean age = 68.7 year) were included, 225 men (55%) and 245 (59.9%) with dual-chamber pacemakers. The mean follow-up period was 18 ± 2 months, with HF incidence in the study group being 23.2%. The results showed that average, septal, and lateral MAPSE all correlate well with LVEF, but septal values seemed to provide the strongest correlation (r = 0.90, p < 0.001), and that a septal MAPSE cut off value of <10 mm (sensitivity 99.4, specificity 42.1, AUC = 0.89) was associated with impaired LVEF (<50%). Conclusions: MAPSE seems to corelate well with LVEF across the spectrum of HF in pts with chronic RV conventional pacing. Septal MAPSE shows the strongest correlation with LVEF, and a value of <10 mm is a cut-off for altered LVEF, making it a potentially useful marker of cardiac function in these pts.

Background: The role of digoxin in atrial fibrillation, particularly in patients with heart failure, has long been debated. Observational studies reporting higher mortality have fueled skepticism, yet growing evidence suggests that these findings largely reflect prescription bias, confounding by indication, and inadequate adjustment for serum-level rather than intrinsic toxicity. Objective: To reassess digoxin’s role in atrial fibrillation with heart failure using contemporary evidence and to propose a physiology-based, personalized monitoring framework. Evidence review: We reevaluated the studies that initially linked digoxin to excess mortality and reassessed these associations through three analytic pillars: randomized evidence, bias deconstruction, and exposure–response relationships. Across datasets, low serum digoxin concentrations were consistently associated with stable resting rate control without increasing mortality. Key findings: Low-dose, continuously administered digoxin is a viable second-line option for atrial fibrillation rate control in patients who are hypotensive or intolerant of β-blockers. Safety is concentration-dependent; adverse outcomes increase at higher serum digoxin concentration (≥1.2 ng/mL). Resting heart rate can serve as a contextual surrogate of exposure: persistent HR > 100 bpm in stable patients usually reflects underexposure rather than digoxin toxicity, whereas bradycardia should prompt immediate serum digoxin concentration testing. Proposal: A probability-based monitoring model that integrates heart rate, renal function, dosage, electrolytes, and drug–drug interactions to guide when serum digoxin concentration measurement is warranted. As a future direction, a supervised “pill-in-the-pocket” supplemental dose strategy could be evaluated for transient tachycardia in selected, stable patients. Conclusions: When properly dosed and contextually monitored, digoxin remains a safe, effective, and individualized rate-control option in atrial fibrillation with heart failure. Prospective validation of probability-guided monitoring and evaluation of a “pill-in-the-pocket” approach could simplify digoxin management while maintaining safety.

Objectives: This review aims to systematically evaluate the clinical outcomes of left ventricle-only fusion pacing (LV-only fCRTp) and identify evidence-based selection criteria that may optimize patient response and long-term therapeutic benefit. Background: Cardiac resynchronization therapy (CRT) is traditionally associated with biventricular pacing (BiVp). However, approximately 20–40% of patients seem to remain non-responders to this therapy. LV-only fCRTp offers a more physiological alternative by combining left ventricular epicardial pacing with the intrinsic ventricular activation wavefront. Beyond optimization strategies, the observed variability in response highlights the need for better patient selection in order to fully unlock its therapeutic potential. Methods: A systematic literature search was conducted in PubMed and Cochrane Library for original articles published up to April 2025, following PRISMA 2020 guidelines. The search focused on LV-only fCRTp performed either through standard RA/LV/RV biventricular devices or RA/LV dual-chamber systems. Results: Twenty-seven studies met the inclusion criteria. Among these, 17 studies obtained LV-only fCRTp using biventricular devices, and 10 were considered true LV-only fCRTp using RA/LV dual-chamber devices. Standard and specific selection criteria were used to qualify patients for LV-only fCRTp. Preserved atrioventricular conduction, ischemic cardiomyopathy, arrhythmic risk stratification, and the management of supraventricular arrhythmias were common overlapping parameters among studies with high variability, highlighting their potential role in response. RA/LV devices yielded consistent clinical benefits and low complication rates, particularly in nonischemic patients with stable AV conduction and low arrhythmic risk, while having a lower financial burden. Conclusions: Beyond guideline recommendations for CRT, this review identifies supplementary selection criteria that could further influence the effectiveness and stability of fusion pacing.

Background/Objectives: Cardiac resynchronization therapy (CRT) with fusion pacing (“LV only”), also known as fusion-CRT (f-CRT), represents a feasible alternative to cardiac resynchronization therapy (CRT) with biventricular pacing (BiVP), not only in cases of BiVP failure, but also as a primary therapy option due to its potential benefits over traditional CRT. Fusion pacing may be particularly beneficial in selected patients and understanding the structural and functional differences between responders could guide future optimization strategies. This study provides a descriptive comparison between super-responders (SRs) and non-super-responders (NSRs) undergoing fusion-CRT. Methods: Patients with RA/LV-only pacing systems or biventricular CRT systems operating predominantly in LV-only pacing mode due to intrinsic RV conduction were included. A follow-up protocol was conducted for all patients at 6 months and then annually. Data from the most recent follow-up were used for statistical analysis. Super-responders (SRs) were those with substantial reverse remodeling, quantified by a ≥30% reduction in LVESV and a stable LVEF of ≥45% at follow-up. Although SRs were defined based on these reverse remodeling criteria, separate analyses of additional echocardiographic parameters (e.g., left atrial dimensions) were performed to independently assess the broader impact of fusion-CRT on cardiac structure and function. Results: Among 71 patients, 55 were non-super-responders (NSRs) and 16 were super-responders (SRs), with a mean follow-up of 43.2 months. SRs were predominantly female and had smaller left ventricular (LV) dimensions: LVEDd (6.30 cm vs. 6.80 cm, p = 0.02), LVEDV (185 mL vs. 240 mL, p = 0.03), LVESV (132.5 mL vs. 175 mL, p = 0.03), and a higher LVEF (p = 0.03). The follow-up LVEF was positively correlated with changes in LVESV (ρ = 0.557, p < 0.001), but not with NYHA class changes (ρ = 0.184, p = 0.125). Larger baseline LV and left atrial (LA) volumes were associated with a reduced follow-up LVEF (LVESV: ρ = −0.426, p < 0.001; LVEDV: ρ = −0.394, p < 0.001; LAv: ρ = −0.374, p = 0.001). Both groups showed improvement in the NYHA class (p < 0.001, p = 0.007). MR improved significantly in SRs (p = 0.02) and worsened slightly in NSRs (p = 0.13), while TR worsened significantly in the NSRs group (p = 0.03). Conclusions: Our findings highlight key differences in clinical and echocardiographic parameters between SRs and NSRs following fusion-CRT. These observations may contribute to a better understanding of response patterns and inform future prospective studies aiming to optimize patient selection and timing of therapy.

Background: The Heart Rate Recovery Index (HRRI), derived from post-exercise heart rate recovery (HRR), reflects autonomic function and cardiovascular performance. Whether HRRI reflects early myocardial dysfunction and left atrial remodelling in heart failure with preserved ejection fraction (HFpEF) has not been previously examined. The H₂FPEF score, which integrates clinical and echocardiographic parameters, is used to assess the likelihood of HFpEF. This study investigates the relationship between HRRI, H₂FPEF score, and echocardiographic markers of longitudinal systolic function, including mitral annular plane systolic excursion (MAPSE), as well as left atrial volume index (LAVI), in patients with preserved left ventricular ejection fraction. Methods: A prospective observational study included 241 patients referred for cardiac exercise testing at the Institute of Cardiovascular Diseases Timisoara and the Clinical County Hospital of Sibiu. HRRI was calculated as the ratio of heart rate acceleration time (AT) to deceleration time (DT) during exercise testing. A comprehensive echocardiographic assessment was performed on all patients. Statistical analysis involved univariate testing and multivariable logistic regression with stepwise selection. Results: HRRI was significantly lower in HFpEF patients compared with those without heart failure (1.97 ± 0.66 vs. 2.73 ± 1.08, p < 0.01). HRRI correlated significantly with exercise performance, age, H₂FPEF score, and echocardiographic markers of diastolic and longitudinal systolic dysfunction. ROC analysis identified an HRRI cut-off value of 2.25 for HFpEF detection (AUC = 0.748), while HRRI remained significantly associated with HFpEF after adjustment for the covariates included in the model. The combined HRRI–H₂FPEF score improved diagnostic discrimination compared with the H₂FPEF score alone (AUC 0.897 vs. 0.858), achieving an overall classification accuracy of 82.2%. Conclusions: In our study, HRRI is significantly reduced in HFpEF and distinguishes patients with and without heart failure. It shows associations with echocardiographic markers of diastolic and longitudinal systolic dysfunction, exercise capacity, and H₂FPEF score.