Cardiac catheterization is a medical procedure in which a catheter (a thin, flexible tube) is guided through a blood vessel to the heart in order to diagnose or treat certain heart disorders, like irregular heartbeats or clogged arteries.

Cardiac catheterization may be done to:

• Diagnose a heart disease
• Check how the heart muscle is working
• Perform certain heart treatment, like the placement of a stent in case of a blockage

Some of the commonly performed procedures using cardiac catheterization include:
1. Angioplasty: A catheter with a small balloon at the tip is inserted by a doctor. On inflating the balloon, the plaque is pushed out and the artery is widened.
2. Biopsy: A small tissue sample is taken from the heart by the surgeon and sent to the lab for evaluation.
3. Repairing heart defects: A hole in the heart can be closed and a leakage in a heart valve can be stopped using cardiac catheterization.
4. Placement of stent: A tiny mesh tube, known as a stent, can be placed into the artery by the surgeon to help keep it open.
5. Valve replacement: A minimally-invasive procedure known as Transcatheter Aortic Valve Replacement (TAVR) may be used to replace a faulty aortic valve (heart valve).

The following tests may be performed before a cardiac catheterization procedure:

1. Physical examination: The overall physical health of the patient is evaluated by the doctor. The symptoms and medical history of the patient are also noted.
2. Blood tests: A blood test helps in the diagnosis of certain medical conditions like diabetes, kidney disorders, and thyroid diseases.
3. Electrocardiogram (ECG or EKG): This test helps to measure the electrical activity of the heart. It helps in the diagnosis of various heart problems.
4. Chest x-ray: It helps to check the condition of the heart and lungs.
5. Echocardiogram (echo): It helps in obtaining clear images of the internal structure of the heart.
6. Stress test: This test helps in evaluating how well the heart functions during physical activity, like walking on a treadmill, or by giving medication.
7. Imaging tests: Imaging tests like cardiac CT scans and cardiac MRI scans help in obtaining clear images of the heart.

The following preparation may be required before a cardiac catheterization procedure:

• Your doctor should be informed about any medications, herbs, or supplements that you may be currently taking.
• Tell your doctor if you are suffering from any medical conditions.
• In the case of a diabetic patient, the doctor will tell you to adjust your medication dosage on the day of the procedure.
• If you are allergic or sensitive to any medications, anesthetic agents, latex, iodine, or tape, let your doctor know about the same.
• The doctor may recommend stopping taking blood-thinning medications like aspirin and warfarin a couple of days before the procedure.
• You will be told not to eat or drink anything after midnight the day before the procedure.

The procedure for cardiac catheterization is as follows:

• An intravenous (IV) line is placed in a vein in the arm of the patient.
• A medication is given through the IV to help the patient relax, or make the patient sleep during the procedure.
• The doctor will give local anesthesia (a numbing agent) at the site of the catheter insertion.
• The site of catheter insertion is known as an access site and may be present in the arm, thigh, neck, or under the collarbone.
• A needle is inserted into a blood vessel at the site of access by the doctor.
• A small cut or incision may be made by the doctor to access the blood vessel.
• The doctor then inserts a guidewire into the needle. The needle is then removed.
• A small tube, known as a sheath, is then placed in the blood vessel around the guidewire.
• The doctor now removes the guidewire.
• The catheter is inserted through this sheath. 
• The doctor takes x-rays intermittently to check where to place the tip of the catheter.
• Once the catheter is in its place, the doctor may use it to perform various diagnostic tests or heart treatments.

The following procedures may be performed using cardiac catheterization:

1. Coronary angiogram: A dye may be injected into the catheter to check the blood flow in the heart and if there are any blockages in the arteries. The dye will enter the blood vessels and make the coronary arteries more apparent in the x-ray images. The catheter is usually placed in the artery in the wrist or groin area.
2. Cardiac ablation: Heat or cold energy is used for creating small scars in the heart to block the abnormal electrical signals of the heart and restore a normal heartbeat.
3. Heart biopsy: A sample of heart tissue is taken by the doctor using a catheter with a small, jaw-like tip and sent to the laboratory for evaluation. The catheter is usually placed in the vein in the neck, and sometimes in the groin area.
4. Balloon angioplasty: The catheter insertion is usually in the wrist or groin area for this procedure. The catheter is guided to the artery which is narrowed and a smaller balloon catheter is then inserted through the flexible catheter, and inflated at the area which is narrowed to open it. A mesh coil, known as a stent, is often placed at the narrowed part to keep the artery open.
5. Right heart catheterization: A catheter is inserted in the vein in the neck region or groin area. The catheter consists of special sensors that help in measuring the pressure and blood flow in the heart.
6. Congenital heart defects repair: Catheters can be inserted in the arteries and veins of the groin and neck region to close a hole in the heart, which is a congenital heart defect.
7. Balloon valvuloplasty: A catheter is threaded across a defective valve and a balloon is then inflated to allow the valve to open easily.
8. Heart valve replacement: A faulty heart valve can be replaced by an artificial valve using cardiac catheterization. The procedure takes approximately 30 minutes to complete. However, the time taken may be more or less depending on the type of procedure being performed.

The following post-procedure steps are followed after cardiac catheterization:

• Pressure is applied to the site of the puncture to stop the bleeding.
• The patient is asked to keep his/her leg straight and not get out of bed.
• The heartbeat and other vital signs are checked during recovery.
• If you have any pain, swelling, or bleeding at the site of puncture, or any chest pain or discomfort, inform your doctor.
• Follow all the instructions given by the doctor after going home.
• Most people can resume their daily activities the day after the procedure.
• It is normal to have mild pain and bruising at the site of puncture.
• In case of bleeding from the site of puncture, lie flat and firmly press on it for a few minutes.

Contact your doctor if you notice the following:

• The area around the catheter insertion looks extensively bruised
• The area of catheter insertion becomes numb or tingles
• Your feet turn blue or cold
• There is swelling at the site of catheter insertion
• There is fluid drainage from the site of catheter insertion

The following complications are associated with cardiac catheterization:

• Infection
• Bleeding 
• Blood clot formation
• Allergic reaction to anesthesia or the dye used 
• Air embolism (a life-threatening condition in which the air gets into the blood vessel)
• Blood vessel perforation (a hole going through the blood vessel)
• Heart attack
• Kidney damage due to the dye
• Arrhythmia (irregular or uneven heart rhythm)
• Stroke (a condition in which the blood supply to the brain is stopped)

The cost of cardiac catheterization varies depending on the type of procedure performed, the symptoms of the patient, and the overall health of the patient.
The cost varies amongst different cardiac surgeons across different hospitals and usually varies between INR 16,000 to INR 20,000.