The newest addition to cardio-pulmonary unit
By Robin Earl
A stress test—putting stress on the body through exercise—is an invaluable tool used to assess a person’s cardiac function. Commonly, the patient walks on a treadmill that gradually picks up speed and increases its incline as technicians monitor the patient’s vital signs and symptoms. The patient exercises until reaching a target heart rate, and then continues until he or she reaches a maximum heart rate.
A cardiologist may order the procedure when a patient complains of chest pain or pressure, shortness of breath, or has an abnormal calcium score (a non-invasive CT scan of the heart that measures the amount of calcified plaque in the coronary arteries). If a patient has a family history of heart troubles, a physician may require a stress test prior to a surgery.
But what if a patient can’t use a treadmill? Balance or gait issues, joint pain or dizziness could preclude the use of this stress test staple. And some patients have trouble walking on an incline.
Enter the ergometer bicycle, Fauquier Health’s newest addition to its cardio-pulmonary unit. The high-tech bike gradually increases the tension on the pedals—requiring more effort from the patient—at three-minute intervals. Heart rate and blood pressure are monitored, as well as the patient’s symptoms, if any. Respiratory therapist Angie Tolley explains that a patient’s physician will determine what kind of stress test would be best. “Someone with a walker or a prosthetic might be able to use the bike instead of the treadmill. If a patient cannot get their heart rate up to its maximum on the treadmill, we might switch them to the bike.”
Cardiologist Dr. Neel Shah said, “For the large swath of our population that may be elderly, obese or have orthopedic issues, the bicycle stress test is particularly attractive.”
An added bonus is that echocardiograms can be performed while the patient is on the bike actively exercising, allowing a real-time look at how the heart muscle is functioning. An echocardiogram uses ultrasound to create moving images of the heart. When the exercise echocardiogram is compared to a resting echocardiogram, the cardiologist can determine how the heart is working. If there are sections of the heart that are not moving normally, this suggests the presence of significant blockages in the coronary arteries. This will prompt the cardiologist to consider further testing, such as cardiac catheterization.
Dr. Shah is enthusiastic about the new technology and the enhanced data it can provide. “When we use the treadmill, the patient has to step off the treadmill and lie down before we can take the echocardiogram. The heart rate slows down during the transition so the measured data is not as accurate. On the bike, we can see more directly the heart muscle’s reaction to the exercise. The treadmill echo is about 68 percent sensitive; the bike is closer to 85 percent.”