Cardiac stress testing is commonly used to gauge how well the heart works and to identify if a patient is at risk for cardiovascular disease (CVD). During a cardiac stress test a patient walks on a treadmill or rides a stationary bike. As exercise intensity increases, the heart has to pump harder and use more oxygen. This mimics the strain placed on the heart when arteries are blocked or narrowed. Several parameters are monitored during the stress test including ECG waveforms, blood pressure, and oxygen saturation.