Ventricular Tachycardia Ablation

What is ventricular tachycardia ablation?

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Ventricular tachycardia ablation is a technique used in the elimination of the areas of the heart where erratic electrical signals arise, which can cause the heart to beat ineffectively.

Ventricular tachycardia is a condition that occurs as a result of electrical signals within the lower chambers of the heart (ventricles) causing the heart to beat too quickly. 

The goal of ventricular tachycardia ablation, therefore, is to stop these incorrect electrical signals and restore the normal heart rhythm.

Why is ventricular tachycardia ablation carried out?

Ventricular tachycardia ablation is carried out to control ventricular tachycardia. For those with an implantable cardioverter-defibrillator (ICD), ventricular tachycardia ablation may help reduce the frequency of shocks they receive from the cardioverter-defibrillator device.

Ventricular tachycardia ablation isn’t, however, helpful for all types of ventricular tachycardia, and it’s also not always the first treatment option. Medications and other procedures may first be recommended.

Ventricular tachycardia ablation procedure.

Ventricular tachycardia ablation procedure begins with a sedative that helps you relax. In certain cases, anaesthesia may also be given to place you in a sleep-like state.

Afterwards, a small area close to a vein in the groin is numbed and catheters are inserted into that vein. The doctor then carefully guides these catheters through the vein to the heart.

The catheters used are equipped with electrodes. The electrodes are used to record the heart’s electrical activity and send electrical impulses. This information is used to determine the best place to apply the ventricular tachycardia ablation treatment, either inside the heart or outside the heart.

• Inside the heart: If the abnormal heartbeat originates from inside the heart, specialized catheters are used to transmit electrical energy (this technique is known as radiofrequency ablation) or extreme cold (this is known as cryoablation) to the target area. This damages the tissue and causes scarring. In certain cases, this blocks the electrical signals that contribute to ventricular tachycardia.
• Outside the heart (epicardial ablation): If the abnormal heartbeat is caused by tissues outside the heart, a long needle may be used to access the heart. The needle is inserted through the chest skin and advanced through the lining of the fluid-filled sack (known as pericardium) that surrounds the heart. A sheath (which is a hollow tube) is inserted, and catheters are passed through this tube to access the outside surface of the heart.

Ventricular tachycardia ablation risk.

Some of the major Ventricular tachycardia ablation risks include, but not limited to;

• Vascular complications such as arteriovenous fistula, pseudoaneurysm, dissection, and hematoma (in the leg). 
• Stroke or transient ischemic attack.
• Damage to a major artery or heart valve.
• Heart block.
• Acute exacerbation of heart failure may occur due to either fluid infused via the ablation catheter or stunning effects of the ablation itself.
• Deep vein thrombosis at the site of vascular access.
• Intra-abdominal or thoracic bleeding.
• Damage to abdominal structures (such as liver, pancreas and bowel) or sub-diaphragmatic vessel caused by the epicardial needle.
• Perforation and bleeding of the right ventricle.
• Damage to the coronary arteries or puncture of the lung, caused by the needle used during epicardial access.
• Damage to the coronary arteries, leading to acute heart attack.
• Likely damage of the phrenic nerve, which may lead to paralysis to one side of the diaphragm.

Ventricular tachycardia ablation success rate 

Ventricular tachycardia ablation success rate varies, depending on the patient’s specific heart condition that caused the ventricular tachycardia. The ventricular tachycardia ablation procedure is most effective in patients with normal hearts; in such people the success rate exceeds 90%. For patients with structural heart disease due to scar or cardiomyopathy, the success rate is between 50% and 75% at 6 to 12 months. In cases of recurrence, 2 of 3 patients will still have less severe ventricular tachycardia than before the initial ablation.

FAQs 

What is ventricular tachycardia? 

Ventricular Tachycardia is an abnormal fast heart rhythm that occurs from the lower pumping chambers of the heart (ventricles). The normal heart beats are usually between 60 and 100 times per minute, with the atria contracting first, followed by the ventricles, in a synchronized mode. In ventricular tachycardia, the ventricles beat at a fast rate ranging from 120 to 300 beats per minute and do no longer coordinate with the atria.

How long does ventricular tachycardia ablation take? 

Ventricular tachycardia ablation usually takes 3 to 6 hours.

What happens after a ventricular tachycardia ablation procedure?

After completing a ventricular tachycardia ablation procedure, the catheters are removed but the sheaths are left in place till the blood thinner wears off. This usually requires the patient to lie still for several hours to prevent bleeding from the sites of puncture. There may also be slight discomfort and bruising in the groin area. Some patients may experience self-limited mild chest pain due to inflammation caused by the ablation lesions.

A blood test is carried out to determine if the blood thinners have worn off. Once the results of the blood test is within range the sheaths will be removed. During this period, it is important the legs are kept straight and the head relaxed on a pillow.

Several weeks after the procedure, the groin area may still feel sore and bruised. Therefore, strenuous physical activities and sports should be avoided for 2 weeks after the procedure until this has settled.

For proper care an overnight hospital stay may be necessary to ensure the heart rhythm and general wellbeing are well monitored.