The Purpose of Cardiac Catheterization
The use of contrast with x-ray allows the interior walls of the arteries, as well as the outline of the ventricle, to be viewed in real-time motion. Thus, Cardiac catheterization helps your doctor find the location and severity of blockages within the coronary arteries, and to watch the movement of both the chamber (ventricular) walls and two of the four valves inside of the heart. (Valves act to keep the blood moving in the right direction as the heart pumps.) By watching, interpreting and utilizing computerized measurements, this information can help reveal if you have actual blockages present, how large the blockages are, if your heart muscle is at risk or has already been damaged, and if the valves between the chambers are functioning properly. By examining all of this information, your cardiologist can make the best decisions as to whether treatment is needed or not, and what kind of treatment is best if it is needed.

Coronary Intervention
One treatment option may be percutaneous coronary intervention (PCI), if the amount of blockage is significant enough to potentially cause damage to the heart muscle, or is already doing so. Percutaneous means that, like the diagnostic catheter, the interventional equipment is inserted through a short introducer into the artery. A very small guidewire is moved into the coronary artery, through and past the blockage to be worked on. Over this wire is guided the small balloon, and if appropriate, the stent that will be used to expand the blocked area of the artery. The stent is a small, wire-mesh tube (very much the size and shape of the spring in a ballpoint pen). Some are made of special metals, while others have drug coatings on the metal that is ‘time-released’ to help prevent re-growth of the blockage in that area of the artery (re-stenosis). Additional medications to help prevent re-stenosis will be prescribed for you if you have PCI to treat a blockage.

The Cath Lab has additional equipment that the cardiologist may sometimes choose to use in performing a PCI. There are special wires that have the capability of measuring the amount of blood flow through a blockage, to determine if PCI is needed; these are often utilized when the x-ray pictures don’t clearly indicate how much blockage is present, such as in a curve, twist or branching of an artery. Miniature ultrasound (sound wave) catheters can also be use to go into the coronary artery and “look” directly at the blockage before, and after intervention. This allows the cardiologist to make the best equipment choice and helps verify that stents have been placed in the most advantageous position and manner. Special catheters can help remove large blood clots that have formed in blocked areas of the artery.

Peripheral Artery Intervention (Vascular Services)
Like the coronary arteries, any artery in the body can develop blockages that restrict blood flow to other areas. (Any artery outside of the heart is called a peripheral artery.) Frequently, hypertension and/renal failure may be related to blockages in the renal arteries, while cramping or pain in the leg muscles, especially when climbing or walking, may be related to blockages in the arteries of the legs.

Performed either in the Cardiac Cath Lab or in the Radiology Special Procedures lab, and utilizing many of the same techniques used for coronary arteries, peripheral vascular intervention (PVI) can be one form of treatment for many of these conditions once determined by diagnostic studies. 

Pacemaker Defibrillator
Sometimes heart disease is not based on problems with the physical structures of the heart (arteries, valves, muscle). For some, the electrical system of the heart, which determines how smoothly and regularly (rhythm) the muscles work together, or the speed at which the heart works (rate) can malfunction. This malfunction may cause arrhythmia (abnormal rhythms and rates). When these occur, the heart cannot pump blood efficiently, sometimes to the degree that symptoms or events occur related to the lack of blood flow. Fainting may occur when enough blood does not reach the brain; shortness of breath occurs when not enough oxygenated blood reaches parts of the body or the heart itself. In certain cases, the arrhythmia is severe enough to stop the flow of blood, resulting in death if not immediately treated and reversed.

For slow heart rates, a device called a pacemaker can be implanted. And it does exactly what its name implies; it sets the pace (rate) of the heart when the heart’s own electrical system does not keep the rate high enough or fails completely.

For very fast heart rates or some abnormal rhythms, a device called an internal cardiac defibrillator (ICD) can be implanted. This device “watches” for rates or rhythms that are potentially deadly, and acts as a small, automatic defibrillator, using a small electrical charge to shock the heart. This shock momentarily stops the abnormal rhythm and allows the heart to come back into a more normal rhythm and rate. This device is most often utilized in people who have been diagnosed for potential of lethal arrhythmias, have survived a recent cardiac arrest and/or who have significant heart failure. Sometimes the ICD is utilized to both pace and defibrillate in the same patient.

Both of these device types consist of two parts: a generator (essentially a sensing device and battery) and the lead or leads. Leads connect the generator to the appropriate spot inside the heart chamber, and act to both see (sense) the abnormal heart rate or rhythm, and to deliver the electrical impulses that act to either stimulate the heart to beat faster (pacemaker) or to shock the heart (ICD). Pacemakers have either 1 or 2 leads, while the ICD can have up to 3 leads placed.

Normally, the generator is placed in a “pocket” made between the skin and muscle of the chest, near the collar bone (clavicle). The leads are then threaded through a nearby vein into the heart and attached to the generator. The pocket is sutured closed after the physician assures that the device is properly functioning. As for any surgical procedure, there is a recovery period and education provided about wound care, as well as about how the device functions. Some mild physical restrictions apply immediately after implant until healing is complete.

Generators may need to be changed periodically due to the battery life or change in the individual needs of the patient. Battery life depends on how much the generator is actually in use, but in general is 5 or more years. If a patient is pacer dependent (the generator paces the heart all of the time) or an ICD “fires” (shocks an arrhythmia) frequently, the generator will need changing on a more frequent basis. Leads may or may not be changed at the time of a generator change, dependent upon type and condition or if the patient needs a different capacity lead.

Cardiothoracic Surgery
The implementation of RMH's Cardiothoracic Surgery program has expanded the scope of coronary procedure options to include coronary artery bypass, heart valve replacement, and aortic surgery. Your cardiologist, in consultation with our cardiothoracic surgeons, will determine if you are a candidate for cardiac surgery based on:

• Your specific anatomy.
• The location and severity of blockages.
• The need for valve repair or replacement based on degree of malfunction.