14.7
运动压力测试
介绍
运动压力测试，通常称为跑步机测试，是一种用于评估心血管功能和诊断心脏疾病的无创程序。
定义
运动压力测试通过跑步机或固定自行车测量心脏对运动的反应。胸部电极通过心电图记录心脏的电活动，同时定期监测血压。
目的
- 运动压力测试的主要目的是发现冠状动脉疾病（CAD）的症状并评估现有心脏病的严重程度。 …
运动负荷试验通过使用跑步机或固定自行车测量心脏对运动的反应，来评估心血管功能并诊断心脏疾病。
测试前，护士向患者说明操作流程，指导其穿着舒适的衣物和运动鞋，并确保患者在测试前禁食三小时，同时在前24小时内避免摄入咖啡因、酒精和烟草。
护士连接十个心电图导联，将胸导联置于标准位置。然后将左右上肢电极置于锁骨下方2 cm处，左右下肢电极置于肋骨下缘以下的下躯干部位。
测试过程中，运动从低强度的热身阶段开始，并逐步增加强度，同时持续进行心电图、心率和血压监测。
当出现显著的ECG改变或胸痛、呼吸困难等症状时，试验在达到目标心率前即终止。
阴性结果表现为无心电图改变。阳性结果可能包括ST段压低、T波倒置或其他提示心肌缺血或心律失常的心电图改变，可能需要进一步治疗。
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Q1: What is the purpose of an exercise stress test?
An exercise stress test evaluates cardiovascular function and diagnoses heart conditions by measuring the heart's response to exertion using a treadmill or stationary bicycle. The test discovers coronary artery disease symptoms, assesses existing heart condition severity, determines safe exercise levels, and evaluates the effectiveness of heart treatments.
Q2: How should patients prepare for an exercise stress test?
Patients should wear comfortable clothing and athletic shoes, fast for three hours before the test, and avoid caffeine, alcohol, and tobacco for 24 hours prior. Some medications like beta-blockers and calcium channel blockers may need to be paused 48 hours before testing. The nurse cleans the skin and obtains a resting 12-lead ECG for comparison.
Q3: What parameters are monitored during an exercise stress test?
During the test, continuous monitoring includes electrocardiogram (ECG) to detect ischemic changes and arrhythmias, heart rate to ensure target levels are reached, blood pressure to assess cardiovascular response, and symptoms like chest pain or dyspnea. Physical appearance, skin color, sweating, and perceived exertion are also observed throughout the procedure.
Q4: When does an exercise stress test stop?
The test stops when the patient reaches their target heart rate, which is 85% of maximum heart rate calculated by subtracting age from 220. It also terminates if significant ECG changes occur or symptoms develop, including severe chest pain, dyspnea, dizziness, leg cramps, or other abnormalities requiring immediate cessation.
Q5: What do positive and negative exercise stress test results indicate?
A negative result shows no ECG changes, indicating normal heart function during exertion. A positive result may include ST-segment depression, T-wave inversion, or other ECG changes indicating myocardial ischemia or arrhythmia, which may require further diagnostic testing or treatment interventions.
Q6: What happens after the exercise stress test is completed?
After exercise, the patient is monitored for 10 to 15 minutes until heart rate returns to normal. Monitoring continues until the patient is stable with no concerning symptoms. If myocardial ischemia signs like chest pain or ECG changes such as ST-segment depression or T-wave inversion occur, additional monitoring and interventions may be necessary.
Q7: What are the risks associated with exercise stress testing?
Stress tests are generally safe, but minimal risks include chest pain, fainting, or rarely myocardial infarction. Medical personnel and emergency equipment are available throughout the procedure to manage adverse events. Patients are informed about potential post-test symptoms and specific instructions for abnormal results.