Great  advances have been made in nonsurgical  treatments for certain types of arrhythmias. These techniques,  including ablation and electrical cardioversion,  may restore  normal heart rhythms,  reduce or elimi- nate symptoms,  and reduce  or eliminate  the need for medications  or surgical procedures (such as implantation of a pacemaker or an internal cardioverter-de?brillator).

Catheter Ablation

Catheter ablation is now widely used to treat many types of tachycardia (rapid heartbeat),  including  atrial ?brillation,  atrial ?utter,  and atrial tachycardia,  as well as some  ventricular  tachycardias.  To perform catheter  ablation, a doctor specializing in the treatment of arrhythmias (an electrophysiologist) threads one or more electrode-tipped catheters into the heart chambers and uses some form of energy—usually radiofrequency—to destroy (ablate) abnormal  tissue that is generating extra impulses. The area of tissue that is eliminated is very small (about one-?fth  of an inch across) and is not signi?cant to overall heart func- tion. A small, harmless scar forms at the site, and normal heart rhythm resumes.

The  procedure  has a high success rate and a low risk of complications, and requires only mild sedation and local anesthetic. It causes little or no discomfort, and most people can return to their daily activities in a few days. Many people are cured of their  tachycardia,  so they no longer need to take antiarrhythmic medication.

How Ablation Is Done

If you have ablation  done,  your doctor  will probably  tell you to stop taking  any antiarrhythmic medications  for  several days before  the

procedure.  At the hospital, you will be given a mild sedative and a local anesthetic.  The  doctor will make one or more small punctures  in your groin and in one side of your neck, your elbow, or just under your collarbone. He or she will thread  catheters through your veins or arteries and into the heart. The procedure is done with X-ray guidance via ?uo- roscopy in real time, so the doctor can see the progress of the catheter.

Then  the doctor  often  needs to start  an episode of tachycardia  in order to determine exactly where the arrhythmia is coming from. Using recordings  of electrical activity from inside the heart, he or she “maps” the tissue to locate the problem area. Once the site is identi?ed and the ablation catheter  is positioned,  the radiofrequency energy is turned  on and the abnormal tissue is destroyed. To ensure that all abnormal tissue has been eliminated, the doctor may test you with medications or elec- trical stimulation to see if the tachycardia can be induced again. If it can be, he or she repeats the ablation procedure.  When the tachycardia can no longer be initiated, the catheters are removed. The entire procedure lasts from 2 to 4 hours.

You will stay in the hospital for at least a few hours,  while doctors watch for recurring  symptoms, rhythm  disturbances,  or bleeding from the catheterization sites. You may be able to go home after this obser- vation period, or you may need to stay overnight.

You can probably be moderately active, walking and climbing stairs, almost immediately.  Many people go back to work or school in a few days. Your doctor may recommend that you take aspirin for 2 to 4 weeks to thin your blood so that clots do not form at the ablation sites in your heart. You will probably return  for a follow-up visit to the electrophys- iologist in a few weeks.

Complications from ablation are rare but can be serious. Depending on the type of arrhythmia treated, and where in your heart the ablation is done, you could develop heart block (requiring a pacemaker) or expe- rience bleeding around the heart. However, the chance of heart attack, stroke, or death from ablation is quite rare.

In people with supraventricular arrhythmia and no other  heart dis- ease, a complete  cure of tachycardia is achieved by ablation more than

95 percent of the time. In people with ventricular arrhythmia, the cure rate is also high.

In people with other heart problems, such as a previous heart attack resulting in heart muscle damage or in heart muscle problems, an inter- nal defibrillator  is almost  always implanted  as well (see page  275).

Rather     than     curing     the     tachycardia entirely, catheter ablation helps reduce the number  of times  the  de?brillator  is acti- vated. Sometimes to achieve a cure, though,  more than one session of ablation is needed.

Cardioversion

Cardioversion  is the medical term for restoration of your heart’s normal rhythm.

Cardioversion  can be done  either  chemi-

cally (with drugs) or electrically (with shock). Atrial fibrillation, ventricular tachycardia, and ventricular ?brillation are the  types of arrhythmia most  commonly

treated  with  cardioversion.  Ventricular  ?brillation,  the  most  serious type of arrhythmia, can only be treated  with electrical shock.

If your doctor  chooses to treat  your atrial ?brillation  with antiar- rhythmic  drugs,  he or  she may give you the  medications  to  take at home. But ?rst you take blood thinners  for several weeks. Or the doc- tor may admit you to the hospital to give you the antiarrhythmia drugs either intravenously or by mouth, where hospital staff can check to see how you respond to treatment, and equipment  can be used to monitor your heart rate and rhythm.  Your symptoms, the medication your doc- tor is giving you, and the presence of other heart conditions (if any) will be factors in this decision.

If your  doctor  recommends electrical  cardioversion  (sometimes called direct-current or DC cardioversion), the procedure  will be done in a hospital.  It involves delivering  a synchronized  electrical  current through paddles that  touch  your chest wall and allow the  current  to travel to your heart. The shock causes all of your heart cells to contract simultaneously,  which  stops  the  abnormal  electrical  signals without damage to the heart. Then  the heart returns  to a normal heartbeat.

How Electrical Cardioversion Is Done

Before you have a cardioversion  done, your doctor  will probably pre- scribe blood thinners  such as warfarin for 3 to 4 weeks to reduce your

risk of blood clots. If you take other medications, you should take them as usual unless you are told otherwise. On the day of the procedure,  do not eat after midnight.  Also, do not use any skin lotions on your back and chest, because they could interfere with the cardioversion apparatus.

In the hospital, you will be given an intravenous sedative, possibly by an anesthesiologist.  The  doctor  will place cardioversion  pads (or paddles) on your chest and back, on either side of your heart. The pads are connected  to an external de?brillator  so that your heart rhythms can be monitored and regulated.  Once you are asleep, the doctor  will deliver the shock so that the current  ?ows across your heart. If the ?rst shock does  not  restore  your  normal  heart  rhythm,  the  doctor  can deliver gradually increased levels of current.

After the procedure,  you will probably awaken quickly without  any memory of the experience. You may have some minor chest discomfort or skin irritation where the pads were placed. You will probably be able to go home  within  an hour  after  the  procedure.  Have  someone  else drive you home, and do not drive or try to make any important deci- sions for the rest of the day, until the effects of the sedative are entirely gone. You will need to continue  taking warfarin until  your physician tells you to stop; periodic blood tests will check your clotting time.

Electrical cardioversion restores normal heart rhythms about 90 per- cent  of the  time.  About  half of the  people  who have the  procedure relapse within a year; if so, the procedure  can be repeated.