The varanid lizard possesses one of the largest aerobic capacities among reptiles with maximum rates of oxygen consumption that are twice that of other lizards of comparable sizes at the same temperature. To support this aerobic capacity, the varanid heart possesses morphological adaptations that allow the generation of high heart rates and blood pressures. Specializations in excitation-contraction (E-C) coupling may also contribute to the varanids superior cardiovascular performance. Therefore, we investigated the electrophysiological properties of the L-type Ca²⁺ channel and the Na⁺/Ca²⁺ exchanger (NCX) and the contribution of the sarcoplasmic reticulum (SR) to the intracellular Ca²⁺ transient ([Ca²⁺]_i) in varanid lizard ventricular myocytes. Additionally, we used confocal microscopy to visualise myocytes and make morphological measurements. Lizard ventricular myocytes were found to be spindle-shaped, lack T-tubules and were approximately 190 μm in length and 5-7 μm in width and depth. Cardiomyocytes had a small cell volume (approximately 2 pL), leading to a large surface area-to-volume ratio (18.5), typical of ectothermic vertebrates. The voltage sensitivity of the L-type Ca²⁺ channel current (I_Ca), steady-state activation and inactivation curves and the time taken for recovery from inactivation were also similar to those measured in other reptiles and teleosts. However, transsarcolemmal Ca²⁺ influx via reverse mode NCX current (I_NCX) was 4 fold higher than most other ectotherms. Moreover, pharmacological inhibition of the SR led to a 40% reduction in the [Ca²⁺]_i amplitude, and slowed the time course of decay. In aggregate, our results suggest varanids have an enhanced capacity to transport Ca²⁺ through the NCX and SR suggesting specializations in E-C coupling may provide a means to support high cardiovascular performance.