The period foregrounded autonomic regulation as the central driver of cardiovascular pharmacodynamics, employing pharmacologic provocations to reveal how sympathetic and parasympathetic inputs shape heart rate, contractility, and hemodynamics. Human pharmacodynamic work with propranolol established quantifiable dose–response effects and set benchmarks for clinical pharmacology in angina and hypertension. Methodologically, studies integrated clinical physiology with animal models to develop mechanistic models of cardiac response and to anchor translational implications in therapy.