Is Coronary Angiography Dangerous? Disadvantages of coronary angiography

Causes of complications of coronary angiography Coronary angiography (CAG) is an angiographic method in which a catheter is selectively inserted into the left or right coronary artery and contrast agent is injected to show the direction of the coronary artery and diseased blood vessels. It has been widely used in clinical practice, but patients may develop complications, which require early prevention and treatment. What are the reasons why patients develop complications after coronary angiography?

1. Arrhythmia: Ventricular fibrillation is the most serious complication, and its cause is related to many factors. The main reasons are excessive contrast agent injection, long duration, too deep insertion of the catheter into the coronary artery, and prolonged blockage of coronary blood flow, which leads to myocardial ischemia and ECG instability.

2. Adverse reactions to contrast agents

2.1 Allergic reaction: The incidence of contrast agent allergic reaction is as high as 5%, which is related to the release of large doses of histamine. It usually occurs when the contrast agent is injected and has nothing to do with the dose of the contrast agent. It manifests as varying degrees of urticaria, angioedema, hypotension, etc.

2.2 Renal toxicity: The rate of renal impairment is 2% to 6%, which is mainly related to two factors: ① contrast agent dose; ② whether the patient has a history of kidney disease. The mechanism of renal function damage is that the contrast agent causes vasoconstriction, leading to renal medullary ischemia and high-dose contrast agent directly toxic to renal tubular cells.

2.3 Vagal reflex: It is often seen during and after coronary angiography or when the arterial sheath is removed. A variety of stimuli act on the cortical center and hypothalamus, causing a sudden increase in the tone of the cholestatic autonomic nerves, resulting in strong reflex dilation of small blood vessels in the internal organs and muscles. Patients become pale, have low blood pressure, slow heart rate, yawn, sweat, feel nausea, vomit, have blurred vision, and may even suffer cardiac arrest.

2.4 Hematoma at the puncture site: It is the most common complication of CAG, caused by failure to stop bleeding by compression, premature movement of the punctured limb, or displacement of the sandbag.