Background: While left-bundle-branch-block-related contraction patterns as well as echocardiography-derived strain are variably associated with the volumetric response to cardiac resynchronization therapy (CRT), the role of CMR-derived strain parameters is unexplored. Methods: A total of 50 patients receiving CRT implantation were retrospectively analyzed, all of whom had undergone CMR imaging within one year before, and echocardiography within 6 months before and 6–12 months after CRT implantation. We assessed CMR-derived morphological and functional parameters with regard to the echocardiographic response, defined as a reduction in the left ventricular end-systolic volume of ≥15%. Results: Among the standard CMR parameters, the indexed right ventricular volumes in end-diastole (RVEDVi) (74.5 ± 19.5 vs. 94.8 ± 30.2 mL/m², p = 0.006) and end-systole (RVESVi) (43.2 ± 13.3 vs. 61.6 ± 28.8 mL/m², p = 0.003), as well as the left atrial (LA) area (24.8 ± 3.5 vs. 30.4 ± 9.5 cm², p = 0.020), differed significantly between CRT responders and non-responders. In strain analysis, CRT responders showed a significantly better LA global longitudinal strain (GLS) (25.1 ± 10.4 vs. 15.3 ± 10.5, p = 0.002), LA global circumferential strain (GCS) (27.9 ± 14.7 vs. 17.1 ± 13.1%, p = 0.012), RV GLS (−25.0 ± 6.5 vs. −18.9 ± 7.6%, p = 0.004) and RV free wall strain (−31.1 ± 7.9 vs. −24.9 ± 9.5, p = 0.017). Conclusions: CMR-derived peak septal circumferential strain and RVEDVi correlated with the echocardiographic volumetric response to CRT at 6–12 months.

Wearable sensors enable continuous recording of electrocardiographic, photoplethysmographic, and inertial signals and have accelerated the development of digital biomarkers in cardiovascular medicine. Transthyretin amyloidosis (ATTR) is a progressive multisystem disease characterized by arrhythmia, conduction disturbances, hemodynamic impairment, autonomic dysfunction, and gait abnormalities, making it theoretically suitable for multimodal wearable monitoring. This review summarizes current knowledge on wearable applications in amyloidosis with ATTR serving as an illustrative case, evaluates the plausibility of extrapolating signal-based biomarkers from related cardiovascular and neurological cohorts, and outlines methodological and implementation challenges. ATTR-specific data remain limited to small observational studies, mainly on long-term rhythm monitoring and supervised functional assessment. More comprehensive findings support the extraction of metrics such as atrial fibrillation burden, activity patterns, gait variability, and heart rate variability. However, ATTR-related structural remodeling and high arrhythmia burden may distort conventional digital biomarkers, necessitating disease-specific preprocessing and prospective validation. Wearable monitoring in ATTR is technically feasible and biologically plausible but remains investigational. Before routine integration into care pathways can be recommended, standardized, phenotype-stratified studies are needed that link wearable-derived characteristics to assessed clinical outcomes.

Background: While left-bundle-branch-block-related contraction patterns as well as echocardiography derived strain are variably associated with volumetric response to cardiac resynchronization therapy (CRT), the role of CMR-derived strain parameters is unexplored. Methods: 50 patients receiving CRT implantation were retrospectively analysed, all of which had undergone CMR imaging within one year before, and echocardiography within 6 months before and 6-12 months after CRT implantation. We assessed CMR-derived morphological and functional parameters with regard to echocardiographic response, defined as reduction of left ventricular end-systolic volume ≥15%. Results: Among standard CMR parameters, indexed right ventricular volumes in end-diastole (RVEDVi) (74.5 ±19.5 vs. 94.8 ±30.2 ml/m², P=.006) and end-systole (RVESVi) (43.2 ±13.3 vs. 61.6 ±28.8 ml/m², P=.003) as well as left atrial (LA) area (24.8 ±3.5 vs. 30.4 ±9.5 cm², P=.020) differed significantly between CRT responders and non-responders. In strain analysis, CRT responders showed significantly better LA global longitudinal strain (GLS) (25.1 ±10.4 vs. 15.3 ±10.5, P=.002), LA global circumferential strain (GCS) (27.9 ±14.7 vs. 17.1 ±13.1%, P=.012), RV GLS (-25.0 ±6.5 vs. -18.9 ±7.6%, P=.004) and RV free wall strain (-31.1 ±7.9 vs. -24.9 ±9.5, P=.017). Conclusions: CMR-derived peak septal circumferential strain and RVEDVi correlated with echocardiographic volumetric response to CRT at 6-12 months.

Wearable sensors enable continuous recording of electrocardiographic, photoplethys-mographic, and inertial signals and have accelerated the development of digital bi-omarkers in cardiovascular medicine. Transthyretin amyloidosis (ATTR) is a progressive multisystem disease characterized by arrhythmia, conduction disturbances, hemody-namic impairment, autonomic dysfunction, and gait abnormalities, making it theoreti-cally suitable for multimodal wearable monitoring. This review summarizes current knowledge on wearable applications in ATTR, evaluates the plausibility of extrapolating signal-based biomarkers from related cardiovascular and neurological cohorts, and out-lines methodological and implementation challenges. ATTR-specific data remain limited to small observational studies, mainly on long-term rhythm monitoring and supervised functional assessment. More comprehensive findings support the extraction of metrics such as atrial fibrillation burden, activity patterns, gait variability, and heart rate var-iability. However, ATTR-related structural remodeling and high arrhythmia burden may distort conventional digital biomarkers, necessitating disease-specific preprocessing and prospective validation. Wearable monitoring in ATTR is technically feasible and biologically plausible but remains investigational. Before routine integration into care pathways can be recommended, standardized, phenotype-stratified studies are needed that link wearable-derived characteristics to assessed clinical outcomes.