Cardiac pressure-volume (PV) loops are essential tools for understanding the heart's mechanics and performance, initially used for heat engines and pumps. These loops are generated by plotting real-time left ventricular pressure against volume during a single heartbeat, providing critical insights into hemodynamic parameters such as stroke volume, cardiac output, and ejection fraction. The article defines Afterload as the resistance the heart must overcome to eject blood (e.g., increased by hypertension or aortic stenosis), and Preload as the stretching of the heart muscle before contraction. From these loops, the Stroke Volume (blood ejected per beat) and Cardiac Output (total blood pumped per minute) can be accurately calculated. The area enclosed by the PV loop directly represents the Stroke Work performed by the ventricle, offering a comprehensive framework for assessing myocardial contractility and how various conditions impact cardiac function.