Coronary angiograms



Coronary angiography refers to the procedure that uses contrast dye, usually containing iodine, and imaging to detect blockages in the coronary arteries that are caused by plaque buildup.

Invasive coronary angiography is the reference standard for the diagnosis of obstructive coronary artery disease and enables coronary revascularization during the same procedure.


Coronary angiograms are performed is to visualize the blood in the coronary arteries. 

A catheter is used to administer the X-ray contrast agent at the desired area to be visualized. 

The catheter is threaded into an artery in the forearm or groin and the tip is advanced through the arterial system into the major coronary artery. 

X-ray images of the transient radiocontrast distribution within the blood flowing inside the coronary arteries allows visualization of the size of the artery openings. 

However, presence or absence of atherosclerosis or atheroma within the walls of the arteries cannot be clearly determined.

Coronary angiography can visualize coronary artery stenosis.

Invasive Coronary angiography is associated with rare major procedure related complications and reveals obstructive coronary artery disease in only 38 to 50% of the patients who are referred for the procedure in the United States.

It is a procedure is used to diagnose ischemic heart disease after chest pain, sudden cardiac arrest, or abnormal results from tests such as an electrocardiogram (EKG) of the heart or an exercise stress test. 



Often, coronary angiography is done with a cardiac catheterization procedure. 



Possible complications may include bleeding, allergic reactions to the contrast dye, infection, blood vessel damage, arrhythmias, blood clots that can trigger a heart attack or stroke, kidney damage, and fluid buildup around the heart. 



The risk of complications is higher in people who are older or who have certain conditions such as chronic kidney disease or diabetes. 



Coronary computed tomography angiography may be preferred over coronary angiography to detect blockages in the heart: 



it does not require the invasive cardiac catheterization procedure that causes many of the complications of coronary angiography.


By comparing the width of the lumen of narrowed segments of blood vessel with adjacent vessels allows the determination of the degree of stenosis.


Coronary angiography has limited limited ability to predict the physiological significance of individual coronary artery lesions, especially for intermediate narrowing in the 40-70% diameter stenosis range.


Patients symptoms and outcomes are more related to the physiological consequence from coronary artery lesions than its mere presence, and the magnitude of benefit of a revascularization procedure is directly related to the baseline extent of ischemia and there is a disconnect between an approach for decision-making for revascularization based on imprecise visual estimation of anatomy and the expectation of the physiological benefit of percutaneous coronary intervention.


Fractional flow reserve is a pressure derived measure of maximal myocardial  blood flow beyond stenosis divided by theoretical normal maximal flow in the absence of stenosis, such as fractional flow reserve in a vessel with no obstruction is 1.0.

Fractional flow reserve is a reproducible, lesion specific measure of stenosis severity that correlates with determined ischemia by non-invasive testing.

Fractional flow reserve is measured by advancing a pressure sensor beyond this to gnosis in question and maximum Levi vasodilating in the resistance vessels by administering a potent vasodilator usually adenosine.

CT angiography is superior  to MRI studies to detect coronary artery disease:sensitivity and specificity between CT and MRI were (97.2 percent and 87.4 percent) and (87.1 percent and 70.3 percent), respectively. 

More than 2 million exams done annually in the U.S.

Coronary angiography gold standard to define severity and extent of coronary artery disease, yet it is imperfect for assessing of coronary artery disease severity

Can under or overestimate a lesions functional severity, although it is the standard procedure for PCI guidance in multiple coronary artery disease.

It can overestimate or underestimate lesion severity, especially when only moderate stenosis of 40-80% is present.

There are several factors other than the percentage of the luminal narrowing that determines if a stenosis actually causes ischemia.

Stenosis length, serial lesions, the amount and viability of the myocardium the vessel serves, and the presence of collateral flow are some of the key determinants of why significant stenosis may cause marked ischemia in one patient but not in another.

Angiographic interpretation by experienced angiographers may result in disagreement about that the severity of intermediate lesions.

Frequently underestimates extent of atheroma in arteries as it provides a silhouette of the vessels.

19% of studies are normal.

Women have normal angiography three times more frequently than men.

With new contrast agents the risk of a severe reaction is less than one in 80,000 examinations. 



Damage to blood vessels can occur at the site of puncture/injection, and anywhere along the vessel during passage of the catheter. 


If digital subtraction angiography is used instead, the risks are considerably reduced because the catheter does not need to be passed as far into the blood vessels; thus lessening the chances of damage or blockage.

Among patients with stable chest pain and intermediate pretest probability of coronary artery disease, the risk of major adverse cardiovascular events is similar in a CT group and in an invasive coronary angiography group: the frequency of major procedure related complications is lower with an initial CT scan strategy (The DISCHARGE trial group).



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