A stress test is a diagnostic procedure that evaluates how your heart functions under exertion. It helps medical professionals understand your cardiovascular system’s response to increased demands. The test’s purpose is to identify potential issues with blood flow to the heart or detect irregular heart rhythms that may not be apparent at rest.
Getting Ready for Your Stress Test
Proper preparation for your stress test helps ensure accurate results. Avoid eating or drinking anything, except water, for at least three hours before the test. Also, avoid all caffeinated products, including coffee, tea, energy drinks, chocolate, and certain pain medications, for 24 hours prior, as caffeine can interfere with results. Smoking or using tobacco products should also be avoided.
Your doctor will provide specific instructions regarding medications. You may be asked to temporarily stop certain heart medications, such as beta-blockers or calcium channel blockers, the day before or the morning of the test. If you have diabetes, discuss insulin adjustments with your doctor for the day of the test. Wear comfortable, loose-fitting clothing and athletic shoes to facilitate movement during the procedure.
What Happens During Your Stress Test
Upon arrival, a medical professional will prepare you by attaching electrodes to your chest, and sometimes your arms and legs. These electrodes connect to an electrocardiogram (ECG) machine, which continuously records your heart’s electrical activity. A blood pressure cuff will also be placed on your arm to monitor your blood pressure throughout the procedure.
There are two main types of stress tests: exercise stress tests and pharmacological (medication) stress tests. An exercise stress test involves walking on a treadmill or pedaling a stationary bicycle. The exercise begins at an easy pace, with the speed and incline of the treadmill or resistance of the bike gradually increasing every few minutes. You will continue exercising until you reach a target heart rate, 85% of your maximum predicted heart rate for your age, or if you develop symptoms such as chest pain, severe shortness of breath, dizziness, or unusual fatigue.
For individuals unable to exercise due to physical limitations, a pharmacological stress test is performed. In this test, medications are administered intravenously to simulate exercise effects on the heart, increasing heart rate and blood flow. You might experience sensations similar to exercise, such as a faster heartbeat, warmth, or mild shortness of breath, but these subside quickly.
Throughout either type of stress test, medical staff closely monitor your heart rate, blood pressure, and ECG readings. They will also frequently ask about any symptoms you might be experiencing. This constant oversight ensures your comfort and safety, allowing the medical team to respond immediately to any changes or concerns.
After Your Stress Test
Following the active portion of your stress test, you will enter a cool-down period. If you performed an exercise test, you will gradually slow your pace on the treadmill or bike before sitting or lying down. Monitoring of your heart rate, blood pressure, and ECG will continue until these measurements return to their baseline levels, which takes about 10 to 15 minutes. Once your vital signs have stabilized, you can resume your normal activities unless otherwise instructed.
A cardiologist will analyze the comprehensive data collected during the test. This analysis includes evaluating changes in your ECG, how your blood pressure and heart rate responded to stress, and any symptoms you reported. If imaging was part of your stress test, such as a nuclear stress test or stress echocardiogram, those images will also be reviewed to assess blood flow to your heart muscle.
You will not receive your results immediately after the test. A full report is provided to the doctor who ordered the test within a few days, and a follow-up appointment will be scheduled to discuss the findings. The results will indicate whether your heart’s response to stress was normal, abnormal, or inconclusive. Depending on the findings, your doctor may recommend lifestyle adjustments, additional diagnostic tests like a cardiac catheterization, or specific treatment plans to maintain your heart health.