Related Experiment Video
Updated: Feb 15, 2026

Author Spotlight: Exploring Abdominal VNS for Inflammatory Conditions
Published on: January 19, 2024
Cardiac surgery in a patient with implanted vagal nerve stimulator
Aashish Jain1, Dheeraj Arora1, Yatin Mehta1
1Medanta Institute of Critical Care and Anesthesiology, Medanta The Medicity, Gurugram, Haryana, India.
Abstract:
The prevalence of epilepsy worldwide is around 0.5%-2% of the population. Antiepileptic medications are the first line of treatment in most of the cases but approximately 25%-30% epilepsy patients are refractory to the single or combination therapy. The surgical option for temporal lobe epilepsy is temporal lobectomy, which has its inherent risk of neurological deficits after the surgery. Patients who are either refractory to combination therapy or do not want surgical temporal lobectomy are the candidates for electrical stimulation therapy. Refractory cases require implantable device such as vagal nerve stimulator (VNS). We are reporting perioperative management of a patient, with an implanted VNS, posted for pericardiectomy. It is important for the anesthesiologist to be familiar with the mechanism of VNS for proper perioperative care.
Related Concept Videos
Cardiac Output II: Effect of Stroke Volume on Cardiac Output
Preload
Preload refers to the initial elongation of the cardiac myocytes before contraction and is related to the volume of blood filling the heart at the end of diastole, or end-diastolic volume. The...
Stimulants
Cocaine can be administered via snorting, injection, or smoking. It primarily functions by blocking the reuptake of dopamine, resulting in a euphoric high characterized by an intense sensation of happiness and...
Cardiac Output I:Effect of Heart Rate on Cardiac Output
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart...
The Cardiac Cycle
The Process
Electrical signals—sent from the sinoatrial (SA) node in the right atrial wall to the atrioventricular (AV) node between the right atrium and right ventricle—cause both atria to simultaneously contract. When the signal reaches the AV node, it pauses for approximately a tenth of a second, allowing the atria to contract and...
Cardiac Cycle
During the cardiac cycle, blood flow through the heart is regulated entirely by changing pressure gradients. This sequence of events begins with the heart in a state of total relaxation, known as mid-to-late diastole, during which blood passively flows from...
Cardiac Action Potential
The cardiac action potential process involves a series of phases characterized by the movement of ions across the cardiac cell membranes, leading to the depolarization and repolarization of the cardiac myocytes.
Ionic Basis of Cardiac Action Potentials

