Why the Heart Must Beat: A Physical Derivation of Cardiac Electromechanics from First Principles

From two standard physical principles—the second law of thermodynamics and Ohm's law—we derive that the heart must be at the geometric center of any multicellular aggregate, must pulsate, and must differentiate arteries from veins. A key prediction follows: a critical heart rate exists beyond which the diastolic self-charging window collapses disproportionately. This prediction was verified using public graded exercise ECG data (n=89), detecting a structural breakpoint at approximately 135 beats/min where the diastolic-systolic decline slope accelerates 3.92-fold. Three additional categories of independent public data—cross-species embryogenesis timelines, clinical data of birth circulatory transition, and cross-species allometric scaling—further test the core deduction. The framework uniformly explains nine core observational facts of cardiac physiology that are currently dispersed across separate chapters of electrophysiology, hemodynamics, and pathophysiology. Complete falsification conditions are specified for each deduction.