The afternoon of my first day at North Carolina Heart & Vascular, I sat in for a few stress tests and cardiovascular ultrasounds, all of which were performed by the in-house cardiac sonographer.
Stress tests are tests used by cardiologists to determine how the heart responds to stress by inducing controlled exercise and measuring the heart’s response. Each patient has 11 electrodes attached to their chests, placed to measure and track the electrical signals the heart generates to beat. This representation of the signals is called an EKG or electrocardiogram. Patients are put on a treadmill that has in incline. It begins slow and flat, and in 3 minute intervals, the treadmill both speeds up and the incline is increased. After the patient meets and exceeds their target heart rate (determined by their age and weight), they quickly transition from the treadmill to the table, lying on their sides. This transition is important, because a hardworking heart that is ‘exercising’ may reveal to the doctor any blockages in the arteries, dependent on how the heart is moving.
Cardiac ultrasounds are done the same way whether they are after a stress test or done singularly. These tests can be called ECHOS or echocardiograms. A transducer is used to transmit sound waves into the body and then record the waves the are echoed or returned back to it. These return waves allow the heart to be interpreted, and create an image of the structure on a screen. These tests allow doctors to assess how the heart chambers and valves are working, and thus can allow for condition diagnosis. One patient we saw was an old gentlemen, aged 89, whose heart valves, both the bicuspid and tricuspid, regurgitated. This meant that the blood which should be pumping in one direction instead flowed backwards to previous chambers in between beats, because his valves were separated, and thus did not block and regulate blood flow in between beats. Several other heart conditions and abnormalities can be discovered through the ultrasound.