In the vast majority of patients with angina, their symptoms are caused by typical coronary artery disease (CAD), in which an atherosclerotic plaque is partially obstructing a coronary artery. In these cases, a stress test is likely to show evidence of a discrete blockage in one or more of the coronary arteries, and coronary angiography usually will readily identify the number and location of the obstruction or obstructions.

Indeed, angina is so closely associated with typical CAD in the minds of most patients and many doctors, that patients with apparent angina who have a “normal” angiogram are often told, in no uncertain terms, that their chest discomfort is due to something other than angina. And indeed, a number of non-cardiac conditions can produce chest discomfort.

Sometimes, however, true angina can occur in the absence of typical CAD. Sometimes patients who are experiencing angina with apparently “normal” coronary arteries actually do have a cardiac problem that needs to be diagnosed and treated.

Several cardiac and medical conditions can cause angina even without atherosclerotic plaques that are producing discrete blockages in the coronary arteries. Some of these conditions actually do involve the coronary arteries, while others do not.

Conditions Involving the Coronary Arteries

There are at least four disorders of the coronary arteries that can cause cardiac ischemia and angina without producing blockages that can be seen on angiography. All of these conditions are more commonly seen in women, though they sometimes occur in men.

Furthermore, all four of these conditions have features that ought to alert the doctor (and the patient) that the patient's symptoms are indeed cardiac in nature despite the ostensibly "normal" angiograms and should lead to further evaluation and ultimately to appropriate therapy.

• Vasospastic (Prinzmetal's) angina: Severe spasm of the coronary arteries.
• Coronary microvascular dysfunction: A condition involving the small coronary arteries that cannot be visualized on a coronary artery angiogram.
• Female-pattern CAD: A poorly recognized form of atherosclerotic CAD that is seen mainly in women.
• Coronary artery erosions: An ulcer-like lesion in coronary arteries that is next to impossible to see on angiography, but which can lead to acute coronary syndrome.
• Spontaneous coronary artery dissection (SCAD): SCAD can cause angina in the absence of a typical blockage and occurs much more frequently in women than men.

Conditions Not Directly Involving the Coronary Arteries

Sometimes angina can occur when portions of the heart muscle are not getting enough oxygen even though the coronary arteries themselves are completely normal. Conditions that can produce angina without coronary artery disease include:

• Extremely low blood pressure, as may occur in shock due to hemorrhage
• Severe anemia
• Extremely vigorous exertion
• Severe mental stress (as in broken heart syndrome)
• Severe hyperthyroidism
• Sustained tachycardia
• Severe hypertension
• Severe ventricular hypertrophy
• Severe aortic stenosis

In general, these conditions occur in patients who are quite sick, and the angina is usually just one of an array of symptoms. So doctors taking care of these patients are not likely to be led into a false sense of complacency by the absence of classic CAD.