It is an effective non-invasive test for the diagnosis and evaluation of coronary heart disease, and is valuable in guiding the diagnosis and treatment of coronary heart disease. During the exercise test, blood pressure, heart rate and hemodynamic changes are closely observed, and indications and contraindications are strictly controlled.
Plank exercise test mechanism and program
There are generally two types of human exercise: ① isometric exercise: muscle work, the length of the basic unchanged, while the tension increases significantly, coronary and skeletal muscle vascular resistance increases, coronary perfusion decreases; ② isotonic exercise: muscle work, the tension remains constant, the length of the contraction of the regular, blood pressure rises mildly, the coronary artery blood flow and flow velocity increases, is the healthy people and cardiovascular patients appropriate form of exercise.
Active plate exercise is the highest myocardial oxygen consumption of all currently used equipment exercise, is the closest to the ideal form of physiological exercise, the patient's subjective interference role is also small.
Programs: There are a variety of exercise testing protocols available. The most widely used are Bruce's program, Naughton's program, and ACIP's program. Bruce's program is a variable-speed, variable-slope program, which is the most commonly used program, and it is easy to achieve the predetermined heart rate, but it is not easy to tolerate for patients with poor cardiac function or serious illnesses, and it is not suitable for the precise determination of the ischemic threshold.
The Naughton program is a constant speed variable ramp test, the total work done is smaller, which is more suitable for the sicker patients and can also determine the ischemic threshold more accurately; the ACIP program has a more gentle increase in the exercise load, and the increase in the heart rate and the oxygen consumption is linearly correlated, which is more accurate in determining the ischemic threshold than the other programs, and it has a unique advantage for the patients with known coronary artery disease to understand the progression of their disease.
Contraindications: According to the 2002 U.S. Guidelines for Electrocardiographic Exercise Testing, absolute contraindications include: ① acute myocardial infarction (within 2 days); ② high risk of unstable angina pectoris; ③ uncontrolled arrhythmia causing symptoms or affecting hemodynamics; ④ active endocarditis; ⑤ symptomatic aortic valve stenosis; ⑥ decompensated heart failure.