Why and How is an Electrophysiology procedure done
by admin | April 22, 2022 11:15 am
In an earlier article, we have covered what is Electrophysiology and what is the role of a Cardiac Electrophysiologist[1] (CEP). In this article, we shall cover the why and how of the procedure, which is also called an EP Study.
Why is an EP study done?
A General Physician or a Cardiologist[2] who is treating the patient will recommend an EP study to be conducted in any of the below situations:
Heart Rhythm Disorders (HRDs) or an abnormal heart rhythm (arrhythmias) which is a serious problem with long-term health consequences. They are of different types such as tachycardia, ventricular-tachycardia, bradycardia and supraventricular-tachycardia. An EP study will be done to determine the type of arrhythmias, the severity and the best course of treatment.
Syncope: If the person has fainted or lost consciousness, there could be several reasons for this, some of which are related to the heart. So an EP study will be done to understand the exact cause.
The patient is at the risk of sudden cardiac death: Certain heart conditions increase the risk of sudden cardiac death which can be fatal. An EP study will understand the severity or risk level, so that appropriate action can be taken.
The patient needs cardiac ablation: Cardiac ablation is a process in which heat or Radio-frequency waves are used to correct heart rhythm disorders. An EP study will be done before the ablation to pinpoint the exact location of abnormal heart rhythm. In case the recommended course of treatment is a heart surgery, then the EP study and cardiac ablation will be done before the surgery, all on the same day.
Preparing for the procedure
The EP study is done in a hospital, so the patient will be advised not to eat or drink anything after the midnight that precedes the day of surgery. The procedure is done in a special lab or clinic within the hospital used for outpatient procedures. This will have the necessary X-ray table, TV or camera screens, heart monitors and several, medical instruments, in close proximity. On the day of the procedure, just before the schedule, an IV is inserted into the hand. This is required to deliver sedatives which will make the person slightly sleepy. The procedure is done under local anesthesia most of the time, but in some cases, or if the patient asks for the same, general anesthesia will be given. Either way, it helps reduce patient discomfort.
Just before the procedure, the patient’s arm or groin area, whichever is chosen as the spot of catheter insertion, will be shaved. Then the area will be numbed with local anesthesia[3]. It should remain sterile throughout, so the patient will be tied with soft wrist and arm-straps so that he/she does not touch the area. Then electrodes are placed on the heart and chest, which are connected to heart-beat-monitoring equipment. To measure blood pressure, a BP cuff will be placed on the upper arm.
Then, the clinicians will insert long, thin sheath or hollow tube into a blood vessel in the groin or arm, whichever is chosen. Then thin catheters are inserted into the sheaths and using a moving X-ray equipment, the catheters are threaded all the way to the heart. Sensors placed at the tip of the catheter sends electrical signals to the heart and records its electrical activity. Medications can also be delivered through the catheter that will stimulate mild arrhythmias. For patients under general anesthesia, there is no discomfort, but those under local anesthesia who are experiencing intense chest pain, dizziness, nausea or shortness of breath[4] must immediately notify the CEP or nurses.
Also Read: Is shortness of breath a heart or lung problem?[5]
During the procedure
During an EP study, the doctors may undertake one or more of the below activities:
Take a baseline measurement of the heart’s electrical activity: As mentioned earlier, sensors are placed at the tip of the catheters and these record the heart’s initial electrical activity, at different locations in the heart. This is called an Intra-cardiac Electrogram and it shows how electrical signals are moving through the heart.
Send signals to stimulate arrhythmias[6]: The sensors at the tip of the catheters are used to send electrical signals to different spots in the heart to speed-up or slow-down the heartbeat. In case, the patient has extra electrical signals which are causing the arrhythmias, the doctors can detect where these signals are coming from.
Give medicines to see how they affect your heartbeat: One of the treatments for arrhythmias is medication. But before they are prescribed, the doctors must know how the patient’s heart will respond to the same. So, such medications are delivered through the catheter directly into the heart to either block or slow-down electrical activity in a particular area. The heart’s reaction to the medication reveals the efficacy of the medication, and/or the severity of the condition.
Map the heart: Cardiac Ablation is one of the treatments for arrhythmias. To determine what is the best spot in the heart to perform the ablation, a cardiac mapping is done.
Perform cardiac ablation: If the above steps indicate that it is OK to perform a cardiac ablation now, the doctors will undertake the same, immediately. Either heat or RF waves are used to destroy a small part of the heart tissue which is causing the arrhythmias. The scar tissue so formed from the procedure blocks the abnormal electrical signals and restores the normal heart rhythm.
After the procedure
First, the IV and heart monitors will be removed.
Next, the catheters will be removed and pressure applied to the groin and neck to prevent bleeding.
The patient must lie still in bed for up to six hours in order to help the catheter sites to seal fully. To aid this, the patient will be asked to not move or bend his/her limbs.
The patient will be checked frequently. But in case he/she notices bleeding or feels warm and wet at the site, or intense pain, he/she must call the nurse immediately.
Your heartbeat and blood pressure will be monitored continuously to check for complications.
The doctor[7] may share some of the preliminary findings after the test.
If the patient is feeling well enough, he/she will be allowed to eat and drink at the end of these 6 hours.
Most patients are discharged the same day and must take complete rest for the next 12 hours. The patient may feel soreness at the site where the catheters were inserted, for a few days.
A follow-up appointment will be required. During this, the doctor will discuss the test results and the recommended treatment plan.
Reviewed by Dr Suresh S Venkita, Group Medical Director, Kauvery Hospitals
Kauvery Hospital is globally known for its multidisciplinary services at all its Centers of Excellence, and for its comprehensive, Avant-Grade technology, especially in diagnostics and remedial care in heart diseases, transplantation, vascular and neurosciences medicine. Located in the heart of Trichy (Tennur, Royal Road and Alexandria Road (Cantonment), Chennai, Hosur, Salem, Tirunelveli and Bengaluru, the hospital also renders adult and pediatric trauma care.