As many as 10 to 20 percent of patients may have asymptomatic artery disease despite critical narrowings of arteries. Some patients have particularly high pain thresholds and attribute any symptoms to the flu. Other patients simply do not observe any symptoms. If patients lack an adequate warning system, they can lose portions of their heart muscle to the undiagnosed disease. Asymptomatic patients, therefore, may face greater risks based on their lack of warning markers.

Physicians can use stress testing to tailor an exercise program to the specific needs of patients with asymptomatic coronary artery disease. The heart rate at which the abnormality surfaces during a stress test sets the limit for that patient's exercise tolerance. Pulse rate watches enable patients to exercise safely within the confines of a good supply-and-demand balance in the arteries of their heart.

	Patient undergoing an exercise echocardiogram (stress echo) test.

Asymptomatic patients need to express very clearly to their physicians any change in their ability to exercise. Such changes may indicate a progression in their disease. Possible warning signs include:
• Slower walking pace
• Decreased ability to perform regular exercises
• Increased difficulty climbing stairs
• Development of swollen feet
• Increased sense of general fatigue
• Greater need for sleep
• More frequent urination at night
• Unwanted weight gain despite conscientious diet and exercise