Your Day in the Cath Lab

Cardiac catheterization is a commonly performed procedure in cardiology. It is the most definitive way to determine the presence or absence of coronary artery disease( arteries blocked by plaque) and an excellent way to determine cardiac function and the measure pressure measurements in the heart and lungs. These measurements are often signs of underlying valvular heart disease, cardiomyopathies ( diseases of the heart muscle ) or lung diseases such as pulmonary hypertension. Although this is very common and safe procedure, it is invasive and is anxiety-provoking for many patients. It may be useful to hear about cardiac catheterization from the prospective of a cardiologist.

Cardiac catheterization may be recommended for a variety of reasons but the most common indication is to evaluate for coronary artery disease. Most patients have chest pain, pressure or tightness that I suspect is related to a heart disease. Often there has been a stress test or other non-invasive test that is abnormal, and a more definitive test is needed. At other times, the symptoms are so suggestive of heart disease that catheterization is my initial recommendation. In those instances, the risk of heart disease seems so high that anything less than a unequivocal answer is unacceptable for patient safety and appropriate medical care. Patients that undergo catheterization often have two or more cardiac risk factors such as diabetes and elevated cholesterol. Emergency catheterizations are indicated for patients that are admitted to the hospital with heart attacks.

It is my preference to discuss indications for non-emergent catheterization in a relaxed setting several days prior to the procedure. This allows the appropriate time for questions and explanations, as the day of procedure often comes and goes quickly. The procedure itself is relatively short and typically takes between thirty and forty-five minutes. Once arriving in the cardiac cath lab, a patient receives an intravenous line for access and mild sedation. Small tubes called sheaths are placed into the appropriate artery and sometimes vein. Small amounts of anesthetic solution are placed around the puncture area in order to minimize any pain or discomfort. Most cardiologists gain access through the groin region via the right or left femoral artery and/or vein. Long narrow tubes called catheters are then placed through the sheaths and advanced to the origin of the heart arteries with the use of x-rays as a “road map”. Other catheters may be used to measure pressure in the arteries, veins, and heart chambers. Once access is gained, there is no discomfort to the patient as inner arteries are not sensitive the movement of the catheters. Contrast agents (sometimes called “x-ray dye”) are squirted through the catheters in order to see the arteries. The arteries are visualized from different angles in order to determine the presence and/or extent of blocked arteries. Once all the arteries have been sufficiently seen and pressure measurements are completed, the procedure is finished. We usually use a small protein plug to prevent bleeding during the recovery period.

What’s next? At the completion of the diagnostic cardiac catheterization, there are three essential possibilities:

1. “Normal” arteries. This means that there are no blocked arteries or the blockages are not sufficient for angioplasty ( the use of balloons/stents to open blocked arteries)
2. Coronary artery disease. If there are one or two blocked arteries, I may recommend treatment of the blocked arteries by angioplasty. This procedure uses tiny balloons and usually tubes called stents to reopen blocked arteries. It is highly successful in many patients and is less invasive than coronary artery bypass surgery. It is my practice to immediately proceed with angioplasty/stint when appropriate. From a technical standpoint angioplasty is viable option when the blocked areas have characteristics that have high incidence of success. Factors such as length, location, and plaque composition help determine whether or not angioplasty may be appropriate. Angioplasty patients are generally kept in the hospital overnight for observation.
3. A third possibility is coronary artery bypass surgery. This is a more invasive procedure which requires anesthesia and hospitalization for several days. It is particularly useful when there are many blocked arteries (multi-vessel coronary artery disease).

Patients with normal coronary arteries are typically released two hours after catheterization. “Normal” arteries mean that no obstructing blockages were found. Patients will likely still need to take prescribed medications and continue vigilant monitoring of such this as cholesterol levels and blood pressure. Unfortunately, if symptoms are not due to cardiac disease, a patient could still have symptoms after a truly normal cath. In that setting, other causes should be investigated and treated as indicated. Cardiac follow-up typically includes return office visits for wound care and general cardiology care.