Transcript Slide 1
Radiofrequency Catheter Ablation (Cardiac Ablation) By: Silvia Wong RDSC 326—CVT March 1, 2006 What is Cardiac Ablation? A fairly non-invasive treatment for cardiac arrhythmias (irregular heartbeat)—mostly painless, some discomfort Uses mild sedation and local anesthesia—so patient is awake most of the time Only takes about 2-4 hours to complete, sometimes up to 8 hours Specifically for treatment of different types of TACHYCARDIAS (rapid heartbeat) Other names for cardiac ablation include: Cardiac catheter ablation Radiofrequency ablation Catheter ablation Or just simply—ablation Normal Electrical Activity—a beat Electrical impulse begins in the sino-atrial (SA) node located in the upper right chamber (right atrium) of the heart. The impulse spreads across both atria causing them to contract simultaneously and squeeze blood into the lower pumping chambers (ventricles). While the atria are contracting, the electrical impulse continues through the atrio-ventricular (AV) node. The AV node is the "gatekeeper" to the lower chambers and is normally the only electrical connection between the upper and lower chambers. After a split second pause, the impulse then continues down through both of the ventricles causing them to contract and squeeze blood out to the body and lungs. Types of Treated Tachycardias AV Nodal Reentrant Tachycardia (AVNRT) Accessory Pathway Atrial Fibrillation and Atrial Flutter Ventricular Tachycardia AV Nodal Reentrant Tachycardia (AVNRT) An extra pathway that lies in or near the AV node and causes the impulses to move in a circle and reentering areas it has already passed through Accessory Pathway Extra pathways that exist from birth that connect to the atrium and ventricles and causes signals to travel back to the atrium, making it beat faster Atrial Fibrillation and Atrial Flutter Extra signals originating in different parts of the atrium causing the atria to beat rapidly (A. flutter) or quiver (A. fib) Ventricular Tachycardia A rapid, potentially life-threatening rhythm originating from impulses in the lower chambers of the heart. The rapid rate prevents the heart from filling adequately with blood so that less blood is able to circulate through the body Who’s involved? Cardiologist Electrophysiology (EP) doctor Interventional Radiographer Nurses Equipments Used For guidance: Fluoroscopy (most common) Ultrasound RF Catheter Ablation System (Chilli system) Price: $72,827 Most Common Ablation Catheter RF CONTACTR Dual-curve Ablation Catheter 8F and 7F tip offers unique tip movement allowing for precise mapping and ablation in and around anatomical structures Other Ablation Catheters Livewire TC Bi-directional Ablation Catheter Livewire Spiral HP Steerable Electrophysiology Catheter Pre-Treatment Care Stop taking blood thinning medication three days prior to the procedure Other medications that controls heart rate also need to be stopped, as well as aspirin products Diabetics may need to adjust their diabetes medications or insulin NPO past midnight prior to the procedure, including water, gum, mints, etc. If medications are to be taken, then small sips of water is allowed Even while brushing teeth, patients are not allowed to swallow any water How does it work? EP doctor inserts a catheter into the femoral artery and feeds it to the heart Tachycardia induction Ablation catheter is maneuvered so its electrode tip is in contact with the abnormal tissue Location of the ablation target is determined by a process called “electrical mapping,” in which the catheter is moved from spot to spot to find the appropriate area Energy known as Radiofrequency (RF) energy is turned on This energy “disconnects” the pathway of the abnormal rhythm by destroying small amounts of tissue, ending the disturbance of the electrical flow through the heart If the catheter location is correct, the tachycardia is eliminated Testing is performed to see if tachycardia can be initiated again, if so—procedure is repeated, if not then the catheter is withdrawn out of the body Other forms of energy used: intense cold—cryoablation, freezing the tissue Real Procedure Images Specially-designed, multiple-electrode loop ablation catheter deployed in the left atrium (Left anterior oblique view) Catheter position during a successful ablation of a slow pathway of AVNRT Success Rates It exceeds over 90 percent when used to treat: Supraventricular tachycardia—95% Atrial flutter Rare types of ventricular tachycardia Atrial fibrillation Ventricular tachycardia after a heart attack (lower only 40-50%) Risks Perforation of the heart with leakage of blood into the sac surrounding the heart Perforation of a blood vessel with leakage outside of it Inadvertent interruption of normal conduction (which requires a pacemaker) Stroke Heart attack Death All very rare: A pacemaker is needed in less than 1 in 200 cases Serious complications occur in less than 1 in 500 cases Post-Treatment Care Patients should monitor the procedure site for any redness, swelling, or drainage Incision site should be kept clean and dry During recovery process, patient is placed on a special monitor—Telemetry Monitor Telemetry consists of a small box connected by wires to your chest with sticky electrode patches The box displays the patient’s heart rate and rhythm on several monitors in the nursing unit for the nurses to observe the patient’s condition closely Recovery Time After procedure, patients need to stay in bed for about 1 to 6 hours to prevent bleeding No stitches involved Most patients are discharged the same day, some may have to stay overnight at the hospital During the first 48 hours, fatigue or chest discomfort may be experienced Some may experience skipped heartbeats or short episodes of atrial fibrillation after the procedure After the heart has healed, these abnormal heartbeats should subside Many resume normal activities within a few days