This type of patient is asymptomatic, hence also referred to as asymptomatic coronary heart disease. The mechanism may involve relatively mild coronary artery stenosis and well-established collateral circulation; in some patients, it may be related to a higher pain threshold.

bubble_chart Clinical Manifestations

The patient has no subjective symptoms, but this does not mean there is no risk. Its progression or evolution can be the same as stable angina, potentially rapidly developing into other types of coronary heart disease. Resting, stress, or ambulatory electrocardiograms may show myocardial ischemic changes or severe arrhythmias.

bubble_chart Diagnosis

When resting, stress, or dynamic electrocardiograms show myocardial ischemia such as ST-segment depression or T-wave inversion without other explainable causes, and clinical factors predisposing to atherosclerosis are present, a preliminary diagnosis of occult coronary heart disease can be made. To confirm the diagnosis, selective coronary angiography must be performed.

bubble_chart Prognosis

[Prevention and Treatment]

Actively prevent and treat atherosclerosis to prevent the worsening of atherosclerotic plaques, promote their regression, and facilitate the establishment of coronary collateral circulation.

1. Proper dietary adjustments to reduce daily cholesterol intake can prevent the progression of atherosclerotic plaques and even lead to their regression.
2. For asymptomatic patients, if myocardial ischemia is detected via resting, stress, or ambulatory electrocardiograms, treatment similar to that for angina-type coronary heart disease—such as nitrates, calcium channel blockers, or beta-blockers—may be administered. If lipid levels remain elevated despite dietary changes, lipid-lowering medications should be prescribed.
3. Moderate physical activities, such as Tai Chi, radio calisthenics, or jogging, can help promote collateral circulation, improve exercise tolerance, and increase high-density lipoprotein levels.
4. Quit smoking, as it can induce coronary artery spasms, elevate carboxyhemoglobin levels, and cause endothelial injury. Therefore, quitting smoking has a definite role in preventing and treating coronary heart disease.

bubble_chart Differentiation

This type must be differentiated from the following conditions.

1. Autonomic dysfunction: One form of this disease manifests as increased excitability of adrenergic β-receptors, leading to elevated myocardial oxygen consumption. Electrocardiogram (ECG) may show ST-segment depression and T-wave inversion. Clinically, patients often exhibit nervousness, tachycardia, profuse sweating on the palms and underarms, and occasional sighing respiration. After administering 10–20 mg of propranolol, an ECG performed 2 hours later, once the heart rate has slowed, may reveal normalization of the ST segment and T wave, which aids in differentiation.

   Another form, primarily observed in middle-aged women, may be associated with excessive vagal tone and presents as false-positive exercise test results. The key points for differentiation are as follows:

   (1) ST-segment depression appears on the ECG immediately after exercise and resolves rapidly;

   (2) When the patient remains upright after exercise, ST-segment depression may persist and even worsen, but it normalizes quickly upon assuming a supine position. In contrast, ischemic ST-segment depression is unrelated to posture;

   (3) Persistent ST-segment depression may be observed in lead aVF.

2. Various other conditions, such as myocarditis, cardiomyopathy, pericardial diseases, multiple cardiac disorders, electrolyte imbalances, endocrine diseases, and certain medications, can also cause ST-segment and T-wave changes. Differentiation can be made based on medical history and clinical manifestations.