(EP) Electrophysiology and mapping – EP is a diagnostic test to assess your hearts electrical conduction system or activity. These studiues are performed by specially trained Cardiologists, Electrophysiologists, to understand and diagnose an abnormal heart rhythm.
This is done by placing specialized EP catheters up through the right femoral vein into the right side of the heart and running specialised tests to map the electrical currents.
EP Doctors use this study to see:
- Where an arrhythmia is coming from,
- How well certain medicines may work at treating your arrhythmia,
- If they should treat the problem by destroying the cells in the area inside your heart that is causing the abnormal electricial signal. This procedure is called Catheter Ablation.
- If a pacemaker or Implantable Cardioverter Defibrillator (ICD) will help you.
Radiofrequency (RF) catheter ablation has become established as the primary modality of transcatheter therapy for the treatment of symptomatic arrhythmias.
Cryogenic (Cryo) or freezing can also be employed as a means of destroying cells which cause an arrhythmia. It is often used for atrial fibrillation procedures, but can also be used where the pathway of the arrhythmia is very close to the sino atrial node and RF ablation could have a higher chance of destroying the node and pacemaker insertion required.
Common arrhythmias treated
- SVT – Supra Ventricular Tachycardia
- AV- Atrioventricular node Re-entrant Tachycardia
- AVNRT – Atrioventricular Re-entrant Tachycardia e.g. Wolff-Parkinson-White Syndrome – WPW
- Focal Atrial Tachycardia
- Atrial Flutter
- AF – Atrial Fibrillation
- VT – Ventricular Tachycardia
Cardioversion – Cardioversion is a medical procedure which converts an abnormally fast heart rate or cardiac arrhythmia to a normal rhythm by using electricity or drugs. We usually use synchronised electrical cardioversion to deliver a therapeutic dose of electric current to the heart at a specific moment in the cardiac cycle. This “resets” the heart rhythm to normal. It is done under sedation given by an anaesthetist. Sometimes a T.O.E. (see T.O.E), is performed just before the cardioversion to ensure there is no clot present in the heart.
All patients should have been taking anticoagulant medication for several weeks prior to a cardioversion.
Pacemaker Insertion – The contraction of heart (cardiac) muscle is initiated by chemical and electrical impulses. Disease or damage to the body’s intrinsic conduction system may occur at any stage resulting in an insufficient pumping rate to meet the needs of your body for blood and oxygen supply. An artificial pacemaker may be used to produce impulses synthetically.
There are three basic types of permanent pacemakers, classified according to the number of chambers of the heart involved and their basic operating mechanism
Single-chamber pacemaker. In this type, only one pacing lead is placed into a chamber of the heart, either the atrium or the ventricle.
- Dual-chamber pacemaker. Here, wires are placed in two chambers of the heart. One lead paces the atrium and one paces the ventricle. This type more closely resembles the natural pacing of the heart by assisting the heart in coordinating the function between the atria and ventricles.
- Rate-responsive pacemaker. This pacemaker has sensors that detect changes in the patient’s physical activity and automatically adjust the pacing rate to fulfill the body’s metabolic needs.
The outer casing of pacemakers is designed so that it will rarely be rejected by the body’s immune system. It is usually made of titanium, which is inert within the body.
Placement of a pacemaker must be checked by X-ray and a pacing check must be done prior to discharge.
- Speed up slow heart rhythm
- Help control an abnormal or fast heart rhythm
- Make sure the ventricles contract normally if the atria are fibrillating instead of beating with a normal rhythm
- Co-ordinate the electrical signalling between the upper and lower chambers of the heart
- Co-ordinate the electrical signalling between the ventricles. Pacemakers that do this are called Cardiac Resynchronization Therapy devices (CRT). CRT devices are used to treat heart failure
- Prevent dangerous arrhythmias caused by a disorder called Long QT syndrome
- Internally Defibrillate (ICD)
Pacemaker Lead Removal – If pacemaker leads break, or the leads are carrying infection to other structures in the hear,t they may need to be removed.
Monitoring device implant – often called Implantable Loop Recorders. They are now very small devices that are inserted just under the skin of your chest under local anaesthetic.
This is a useful diagnostic tool when patients experience symptoms such as syncope , seizures, recurrent palpitations, lightheadedness, or dizziness regularly but not often enough to be captured by a 24-hour or 30-day external monitor. Implantable loop recorders have a long battery life (2 to 3 years) and so the heart can be monitored for an extended period.