Not all forms of angina match "classic" angina symptoms and triggers. Some forms occur at night, or while the individual is at rest. Symptoms may be absent altogether, or they may include unusual symptoms such as dyspnea (difficulty breathing). Other types of angina, such as variant angina and Syndrome X, cause chest pain but present with normal angiography test results.

Silent angina does not cause chest pain. An angina attack can occur and the individual won't even notice it. Also known as silent ischemia, silent angina may be detected by an EKG stress test. If symptoms are present, they may include jaw pain or dyspnea.

 

People with diabetes have a high risk of both angina and nerve damage. Nerve damage may mask angina pain, resulting in silent angina.

Nocturnal angina occurs at night, and is thought to be triggered by REM sleep. Dreaming may increase heart rate and cause angina symptoms.

Atherosclerosis is a common cause of angina. Atherosclerosis refers to fatty plaque deposits that build up in the coronary arteries and reduce blood flow. Angiography is used to detect signs of atherosclerosis.

 

Variant angina and Syndrome X both present with classic chest pain, but angiography shows no evidence of atherosclerosis.

Coronary artery spasms cause variant angina, or Prinzmetal's angina. Atherosclerosis does not cause variant angina, although plaque deposits do aggravate the condition.

 

Variant angina can occur without physical or emotional triggers. Attacks tend to come in "clusters" of two or three, they may occur every day at a predictable time, and they tend to occur late at night or in the early morning hours. Midnight to eight o'clock in the morning is the peak time period for variant angina attacks.

 

Treatment with calcium channel blockers may help alleviate variant angina by relaxing blood vessel muscles.

Syndrome X presents with stable angina symptoms. Exercise stress tests indicate ischemia, but angiography is normal.

 

Diagnosticians must rule out other causes of pain, such as gastrointestinal or muscle disorders, before they can diagnose Syndrome X. Women are at higher risk of Syndrome X than men.

 

Beta blockers are the primary treatment for Syndrome X.

 

The exact cause of Syndrome X is unclear. Some specialists speculate that it may be caused by damage to the tiny arteries in the heart that is not yet visible on a coronary angiogram. These micro arteries may be damaged by hypertension, atherosclerosis, or other types of heart disease.