Restenosis

Restenosis refers to the re-narrowing of the coronary artery after an Angioplasty procedure. It literally means reoccurrence of the stenosis (narrowing of the blood vessel). Restenosis occurs within 3-6 moths in 40-50% of people who have undergone an Angioplasty.

During the procedure of angioplasty a balloon is inserted into the blocked artery and inflated so as to allow the blood to flow normally to all portions of the heart. During this procedure the surrounding tissues undergo trauma and become susceptible for damage. Restenosis may set in during thrombosis or due to fresh tissue growth at the site of the surgery. Restenosis does not indicate progression of the heart disease but may be an indication that the body's immune system is responding to the injury caused during angioplasty.

Modern medicine has seen the use of stents to keep the artery open. Usage of stents has brought down restenosis considerably. Usage of drug-eluting stent allows slow seepage of medication that reduces proliferation of cells thus reducing re-clogging.

Restenosis causes and treatment

Restenosis is mainly caused due to a surgery that unblocks or widens a blood vessel. Treatment depends on the clinical condition:

• If the original surgery had no stent, then a repeat surgery is performed and a stent is fixed.
  
• In case restenosis occurs even after stent has been placed during the first surgery then a repeat angioplasty is done.
  
• Many a times a second stent may also be placed.
  
• Bypass surgery wherein the affected portion of the artery is replaced with another artery from the patient's thigh.
  
• Brachytherapy; wherein radiation is used to remove the scar tissues from inside the artery.

Cardiac Catheterization

Cardiac catheterization is a test which is performed to obtain certain diagnostic information about the heart. Patients may require this medical therapy rather than undergo angioplasty or bypass surgery when they suffer from rare or easily controlled episodes of angina. Alternatively, cardiac catheterization is not performed in patients who have infrequent episodes of angina and in whom angina can be easily controlled. When a patient has heart failure due to suspected coronary artery disease or there is suspected coronary artery disease, cardiac catheterization is conducted. Cardiac catheterization can help:

• Measure blood pressure within heart.
  
• Know the amount of oxygen in the blood.
  
• Check the pumping ability of the heart muscle.
  
• Check blood flow through the heart after surgery.
  
• Collect blood samples from the heart.
  
• Inject dye into the coronary arteries.
  
• To provide treatment in certain types of heart conditions like congenital heart defects and how severe it is.
  
• To find out a coronary artery disease and if found to pinpoint the size and location of fat and calcium deposits that have built up in coronary artery from atherosclerosis.
  
• To determine whether the patient needs bypass surgery or angioplasty.
  
• Examine the arteries of the heart with an x-ray technique called fluoroscopy.

The patient is asked not to drink or eat anything, except a small amount of water, for at least 6 to 12 hours before the test. The patient is tested for allergy to iodine or other medications. Patients suffering from kidney disease or diabetes or bleeding disorders must keep the cardiologist informed. The cardiac catheterization test is performed in a cath lab by a cardiologist. The actual catheterization procedure takes about 15 - 30 minutes. The patient's electrocardiogram that continuously records the electrical activity of the heart is taken.

A pulse oximeter device that measures the oxygen levels of the patients' blood is monitored. An intravenous needle is inserted into the patients' vein to give fluids or medicine during the catheterization procedure. A sedative is also given through this IV line which helps the patient to relax.

Cardiac catheterization procedure involves passing a catheter, a thin flexible tube, into the right or left side of the heart. The doctor inserts this thin plastic tube into the groin - femoral artery. Other places where in the catheter may be inserted are the elbow- brachial artery or the wrist - radial artery. From there it is slowly advanced into the chambers of the heart or into the coronary arteries. The doctor watches the progress of the catheter into the heart's vessels and chambers on the imaging screen. Pressures within the heart chambers are measured and the blood and tissue samples are also removed through the catheter. A small amount of dye is also injected through the catheter into the heart chamber or into one of the coronary arteries.

Therapeutic catheterization: Certain types of heart defects can be repaired using catheterization. For instance, if the coronary arteries are blocked, the cardiologist can use a catheter, guide wire and balloon to open and improve blood flow to the heart. This is termed as percutaneous coronary intervention (PCI).

Normal result indicate that there is no significant narrowing or blockage in the coronary arteries. Abnormal results may suggest that the heart does not pump blood normally or the valves in the heart may be weak. There may be leakage between heart chambers. There is a possibility of aortic aneurysm. Some complications with cardiac catheterization include heart attack or stroke, hematoma, puncture of the heart or arrhythmia.

Cardiologist

Cardiologists are physicians who diagnose and treat ailments related to the cardiovascular system that comprises of the heart, arteries, and veins. Pediatric cardiologist is a physician who focuses on diagnosing and treating heart problems in infants, children and young adults. Cardiologists specialize in treatment of angina (chest pain), heart attack, heart failure, high blood pressure and irregular heart beats. A cardiologist has to complete medical school and undergo residency in internal medicine for a period of three years. Further three years of specialization in the field of cardiology is required. For pediatric cardiologists a specialization in pediatrics is required prior to cardiology specialization. Cardiologists are specialists who provide complete heart care; they can determine the working condition of a person's heart by means of different tests. The responsibilities of the cardiologist include:

• The primary function of a cardiologist is to check on how well a person's heart is working.
  
• They determine this by asking for various tests like the treadmill test (exercise electrocardiogram), and through procedures like angioplasty, cardiac catheterization etc.
  
• They offer treatments for the diagnosed heart diseases through interventional cardiology like angioplasty, where a mechanical device is used to set right the problem in the heart.
  
• They use electrophysiology that helps in treating the electrical functioning of the heart.
  
• They also have the additional responsibility of keeping control over the factors that determine the health of the heart such as blood pressure and cholesterol levels. These levels in the blood of a person are kept under control thus keeping the heart comfortably functioning.

Modern techniques used in the field of cardiology

With the advancement in the field of medicine, cardiologists have the access to the latest technologies like:

Auscultation: A stethoscope is used to identify and detect heart abnormalities and murmur in the heart.

Echocardiography: Ultrasonic waves are used to visualize the heart.

Electrocardiography: EKG instruments are used to monitor the electrical activity of the heart.

Holter monitor: Records the EKG for 24 hours and more non-stop.

Modern blood tests: Determining the levels of HDL, LDL, triglycerides, homocysteine, and C-reactive protein helps in easy identification of heart problems.

Stress testing: Determines the levels of stress and cardiac function of the heart.

Coronary catheterization: Functioning of the heart is determined by inserting a catheter into the heart.