This thesis presents the Author’s work of novel 12 lead ECG interpretation pedagogies, which includes an overview of methods and principles that have been identified in the acquisition and maintenance of expert performance within ECG interpretation and the development and testing of a clinical decision support system for the acquisition and maintenance of ECG interpretation competence. The work described in this thesis was conducted between 2009 to 2017. The first chapter introduces the background, scope and structure of the thesis. Chapter 2 provides an appraisal of teaching, learning and assessment methods utilised for ECG interpretation instruction. Chapter 3 evaluates the impact incorrect positioning of ECG electrodes, erroneous connection of ECG leads and variable patient postures during ECG acquisition affects the ECG recording. This chapter highlights the constant need for quality control in electrocardiography acquisition and the need for focused training and continuing education of professionals involved in the recording of routine and research ECGs. Chapter 4 establishes expert 12 lead ECG interpretation performance, specifically through patterns of expert behaviour and cognitive psychology. The concepts presented in chapters 2, 3 and 4 describes the rationale, design and development of a novel format to assist with ECG interpretation competency presented within Chapter 5. Chapter 6 summarises the significance of this work, followed by potential future research directions and concluding remarks. This thesis represents multidisciplinary research across the domains of medicine, psychology, clinical & healthcare science, computer science and engineering, that contribute to the quality assurance of 12 lead ECG interpretation competency testing.