To evaluate the work of the left ventricular muscle, aortic and mitral valves or open coronary arteries. This method is used to assess the patient's condition before and after heart surgery. In both left and right heart catheterization methods, there is a possibility of allergic reaction to the contrast agent in the form of nausea, vomiting, flushing, burning sensation, numbness, hives and itchy skin. Anaphylactic shock rarely occurs, so after the use of osmotic diuretics and hydration of the patient helps to expel the contrast agent faster. The patient should fast for 8-12 hours. Tell the client to lie on a firm bed for about 2 hours, give a sedative usually diazepam (5 to 10 mg) and diphenhydramine (25 to 50 mg), and stop taking anticoagulants such as warfarin 48 hours before. Work or only patient PT is 18 seconds. Explanation to the patient There is a strong desire to cough (catheterization of the heart) when the contrast agent is injected. Sudden onset of urination and urination, which resolves within a few minutes. Control vital signs of having an open and suitable vessel, measuring height and weight to calculate the appropriate amount of medication. Explain to the patient that he or she will sometimes feel a throbbing sensation in the chest. This palpitation is due to the extrasystoles that appear, especially when the tip of the catheter hits the ventricular wall. The patient is asked to cough or take deep breaths, especially after the contrast agent is injected. Coughing may interrupt the dysrhythmia and also help the contrast material to pass through the arteries.