Cardiac Cytoarchitecture in Health and Disease -- In Vitro Tools for Quantifying Structure-Function Relationships in Cardiac Myocyte Cells and Tissues -- The Intercalated Disc: A Focal Point for Sarcomere Growth and Disease -- Dynamics of Actin in the Heart: Defining Thin Filament Length -- Ca2+ Regulation of the Cardiac Thin Filament -- Posttranslational Modification of the Titin Springs: Dynamic Adaptation of Passive Sarcomere Stiffness -- The M-Band: Not Just Inert Glue but Playing an Active Role in the Middle of the Sarcomere -- Sarcomeric Signaling -- The Nuclear Envelope in Cardiac Health and Disease -- AMP-Activated Protein Kinase: A Metabolic Stress Sensor in the Heart -- How Cardiac Cytoarchitecture Can Go Wrong: Hypertrophic Cardiomyopathy as a Paradigm for Genetic Disease of the Heart -- Cardiac Cytoarchitecture: How to Maintain a Working Heart-Waste Disposal and Recycling in Cardiomyocytes.