ABLATION FOR SVT AND VT

​

Ablation is a medical procedure used to treat certain types of abnormal heart rhythms, such as supraventricular tachycardia (SVT) and ventricular tachycardia (VT). These conditions are caused by abnormal electrical pathways in the heart, which can lead to rapid or irregular heartbeats. Ablation aims to eliminate these abnormal pathways and restore normal heart rhythm. The procedure is typically performed using catheter-based techniques, which involve the use of thin, flexible tubes called catheters.

​

SVT (Supraventricular Tachycardia) Ablation: SVT is an abnormally rapid heart rate originating in the upper chambers of the heart, called the atria. In an SVT ablation, the catheter is inserted into a blood vessel, usually in the groin, and guided through the vascular system into the heart. Once the catheter reaches the heart, the electrophysiologist (a cardiologist specializing in heart rhythm disorders) uses it to create a detailed electrical map to identify the precise location of the abnormal electrical pathway causing the SVT.

​

Once the pathway is identified, the tip of the catheter is used to deliver radiofrequency energy, cryoablation (freezing), or other energy sources to create small, controlled scars in the heart tissue. These scars block the abnormal electrical signals, thus eliminating the cause of the SVT.

 

VT (Ventricular Tachycardia) Ablation: VT is a potentially life-threatening heart rhythm disorder originating in the lower chambers of the heart, called the ventricles. Similar to SVT ablation, in a VT ablation, the catheter is guided through a blood vessel into the heart. The electrophysiologist then maps the abnormal electrical pathways causing the VT.

​

Once the pathways are identified, the catheter delivers energy (typically radiofrequency or cryoablation) to create controlled scars in the heart tissue. These scars disrupt the abnormal electrical signals, thus eliminating the cause of the VT.

​

Both SVT and VT ablations are generally considered safe, but like any medical procedure, they do carry some risks. These may include bleeding, infection, blood vessel damage, or complications related to anesthesia. In rare cases, more serious complications may occur, such as damage to the heart's normal electrical system, requiring a pacemaker, or injury to the heart tissue, leading to a hole or tear.

 

Overall, ablation procedures have proven to be effective in treating SVT and VT, significantly reducing symptoms and improving the quality of life for many patients.

​

                                                                                                 

                                                          Anesthetic Implications of Ablation for SVT and VT

​

Anesthesia type: General ETT, LMA, local MAC or TIVA

​

Airway: Endotracheal tube or LMA

​​

Preoperative:

​

• Overall cardiovascular and functional status assessment

• Antiplatelet drugs and anticoagulants use should be noted

• Be mindful of exposure to nephrotoxic contrast agents in renal insufficiency patients

• Blood products are normally not required

• Antibiotics are usually not indicated

• An invasive arterial line can be useful , but not required

• Defibrillator pads should be properly positioned

• Antiarrhythmic drugs are normally stopped prior to surgery to make the dysrhythmias more inducible

• Antiarrhythmic agents can cause QTc prolongation

• Ventricular tachycardia often arises from the right ventricular outflow tract (RVOT)

• Ablations for SVT and VT commonly only require right heart access

• A femoral artery sheath may be placed for left-sided ablation (retrograde approach), and pressure can be transduced from the sheath

•  If left-sided study and ablation is planned, heparinization is required to reduce the risk of thromboembolism

​

​

Intraoperative:

​

• The first part of the case involves mapping the myocardium to identify the tissue responsible for initiating the dysrhythmia

• Anesthetics can depress hemodynamic stability and decrease the inducibility of VT

• Isoproterenol can be used during an electrophysiology (EP) study to provoke or induce the arrhythmia

• Isoproterenol is a non-selective beta agonist with chronotropic, dromotropic, inotropic, and vasodilatory effects

• Hemodynamic fluctuation is normally encountered 

• Be aware of the C-arm when it is in motion

• Be mindful of Ionizing radiation dangers

• An esophageal temperature probe can monitor increases in temperature and decrease the risk of esophageal injury

• Phrenic-nerve pacing may be used to locate the nerve and avoid damage from ablation

• Position: Supine with arms tucked

• Duration: 1-3 hours

• ​EBL minimal

​

​

Postoperative:

​​

• ​Monitor for signs of fluid overload or heart failure

• The patient may lie flat for several hours 

​

Complications:

​

• ​Bleeding

• Retroperitoneal bleeding 

• Pericardial effusion

• Cardiac tamponade

• Cardiac perforation

• Femoral vein hematoma

• Puncture of femoral artery

• Arrhythmias

• Complete heart block

• Pneumothorax

• Stroke

• Myocardial infarction

• Embolism

• Hemodynamic fluctuation

• Coronary spasm

• Esophageal injury

• Atrial-esophageal fistula

• Aortic perforation

​​

Sources:

​

Elisha, S. (2010). Case Studies in Nurse Anesthesia.

 

Macksey, L. F. (2011). Surgical procedures and anesthetic implications: A handbook for nurse anesthesia practice. 

​

Jaffe, R. A. (2020). Anesthesiologist's Manual of Surgical Procedures (6th ed.). 

​

Singh-Radcliff, N. (2013). 5-Minute Anesthesia Consult.

​

​

​

​

 

​​

​​