Current methods of subcutaneous post-shock pacing and subcutaneous ventricular fibrillation induction rely on fixed waveform configurations. While these approaches yield high efficacy in therapy delivery, they do not optimise waveforms to accommodate patient comfort or the delivered energy. This study aimed to characterise, in a pre-clinical setting, the cardiac response to subcutaneous pacing thresholds as a function of pulse width and amplitude. The data enabled the generation of strength-duration curves, from which rheobase and chronaxie values were derived for each animal. Although capture currents were significantly higher than those required for conventional endocardial pacing, reliable myocardial capture was consistently achieved. The characterisation data align with classical electrophysiological strength-duration hyperbolic responses. Building on these findings, the study implemented a design-of-experiments framework to assess the impact of waveform parameters on the effectiveness of ventricular fibrillation induction. The results indicated that successful induction is largely dependent on specific waveform settings. Longer pulse durations and higher frequencies lowered the peak current required for induction but increased the average current. These results reveal important trade-offs between stimulation efficiency and device energy consumption. Finally, waveform parameters were evaluated as potential cues for transcriptional organisation in engineered cardiac microtissues. A design-of-experiments structure was implemented, using quantitative polymerase chain reaction to assess waveform-associated changes in the expression of maturation-relevant cardiac genes. This thesis demonstrated that waveform configuration is an important design variable influencing cardiac capture and arrhythmia induction in vivo and is associated with maturation-relevant transcriptional responses in hiPSC-CM constructs in vitro. These findings have implications for the optimisation of S-ICD-related stimulation strategies and electrical conditioning approaches in cardiac tissue engineering.