Multiscale four-dimensional imaging of cardiac remodelling after myocardial infarction.

Myocardial infarction triggers a spatially heterogeneous and temporally evolving remodelling process in which mechanical dysfunction, haemodynamic redistribution and molecular responses interact across multiple biological scales. Conventional imaging approaches typically interrogate these processes in isolation, limiting integrated characterisation of the infarcted heart. Four-dimensional (4D) cardiac imaging integrates temporal dynamics with three-dimensional (3D) ventricular geometry, enabling post-infarction remodelling to be characterised as a coupled spatiotemporal process. Across imaging modalities, the temporal dimension may capture cardiac-cycle dynamics, tracer kinetics or longitudinal biological changes, providing complementary assessment of myocardial deformation, intracavitary haemodynamics and tissue biology throughout disease progression. In this review, we synthesise recent advances in 4D cardiac imaging and organise complementary imaging modalities around three interacting physiological axes of post-infarction remodelling: mechanical, haemodynamic and biological. Echocardiography and computed tomography primarily quantify ventricular geometry and myocardial mechanics. Cardiovascular magnetic resonance provides integrated assessment of myocardial structure, deformation and haemodynamics, whereas nuclear and optical imaging interrogate inflammation, metabolism, electrophysiology and molecular signalling across tissue, cellular and molecular scales. Together, these approaches provide an integrated multiscale framework linking regional biological processes with global ventricular function, thereby advancing mechanistic understanding of post-infarction cardiac remodelling.