How Is Coronary Heart Disease Diagnosed?
Coronary artery disease (CAD), from atherosclerotic narrowing of the coronary arteries and coronary heart disease (CHD), which includes the progression of angina and signs and symptoms of ischemia or worse, are first suspected with a history and physical.
A history can glean a family tendency toward heart disease and explore the patient’s response to exertion, stress, and other challenges. It can also identify co-morbidities that tend to make CAD worse: hypertension, smoking, diabetes, renal disease, medications, and illicit IV drug abuse.
It can also render the pertinent negatives: a history of chest pain must exclude other conditions that can mimic CAD, such as gastritis, esophagitis, pleuritic pain and pneumonia, and diaphragmatic hernia. It is not only important to list the positives, but these negatives, as well, to give an inclusive and complete perspective.
A CAD patient will require additional considerations in the physical exam than others without a cardiac history or cardiac symptoms. Vital signs will identify hypertension, pulse can determine arrhythmias, examination of the jugular veins in the neck can identify heart disease originating from lung conditions, etc.
The familiar wave pattern of an ECG can be assessed. Ischemia renders identifiable patterns in the ECG recording. The 12-lead ECG, which gives a 360° view of the heart, can identify where ischemia is located and can even assign a patient to which part of the acute coronary syndrome he or she is in.
Cardiac ultrasonography can identify structural qualities of the heart as well as the flow dynamics. The presence of thrombi that can predict the risk of stroke or peripheral ischemia can be established and valvular heart disease can be identified.
Stress testing is a way of evaluating the delicate balance between decreased supply (atherosclerotic narrowing) and increased demand (exertion) and at which point a patient is at risk for ischemia. It can be done mechanically with a treadmill or chemically with medication. It uses concomitant use of ECG and possibly echocardiography to complement its accuracy.
- Transthoracic Echocardiography (TTE): Evaluation of Left Ventricular Systolic Function. TTE is the usual method of evaluating left ventricular function. This can be used to determine what type of medical therapy is best, whether interventional or surgical therapy is warranted, or to make recommendations about activity level, efforts at rehabilitation, or employment restrictions.
Coronary angiography is an invasive radiological procedure with risks, so is used when the benefits clearly outweigh these risks. Is indicated for patients whose angina symptoms interfere with their lifestyle or patients who satisfy high-risk criteria:
- Previous cardiac arrest
- Previous life-threatening ventricular arrhythmia with heart failure
- Decreased left ventricular systolic function
- Unsatisfactory quality of life due to angina
The results of coronary angiography allow a risk-vs-benefit decision into the prudence of revascularization via bypass or angioplasty.