Saturday, May 26, 2018

Electrophysiology - What to Expect


Dr. Sanjiv M. Narayan serves as director of the atrial fibrillation and electrophysiology research programs at Stanford University. Dr. Sanjiv Narayan has shared his work through such publications as Circulation, Journal of the American College of Cardiology, Journal of Cardiovascular Electrophysiology which from 2002 to 2017 have published his team's findings on the mapping of irregular heart rhythms.

Electrophysiology (EP) is a category of testing that evaluates the electrical activity of the heart and the patterns that it follows. Often used to evaluate the source of an arrhythmia, or regular heartbeat, it can assist in the development of a course of treatment.

The patient visits an EP or catheterization (cath) lab, where he or she receives a sedative and local anesthetic. The doctor will then make a small incision in the groin, arm, or neck, to thread a small tube known as a sheath into a particular vein or artery. This sheath contains a series of specialized catheters, which the physician will guide toward the heart.

Once the catheters are in place, the physician will send electrical signals into the heart to safely reproduce the irregular heartbeat. The catheters will record the heartbeat in a way that maps the arrhythmia. This allows the physician to identify the source of the abnormality.

The process usually takes between one and four hours. When it is finished, the doctor will remove the catheters. Recovery time, which includes pressure and elevation of the surgical site, usually lasts for one to three hours.

Tuesday, May 15, 2018

Study on Localized Atrial Fibrillation (AF) That Ends Persistent AF


A professor of medicine at Stanford University, Dr. Sanjiv M. Narayan has led basic human heart rhythm disorder research in areas that were little studied. Extensively published in his field, Dr. Sanjiv M. Narayan coauthored “Identification and Characterization of Sites Where Persistent Atrial Fibrillation Is Terminated by Localized Ablation” (Circulation Arrhythmia Electrophysiology, 2018).

With atrial fibrillation (AF) characterized by irregularity of heartbeat and presenting a danger of blood-clot-related stroke, the study sought to increase knowledge of how persistent AF terminates when localized ablation is undertaken. Cardiac ablation involves the elimination or scarring of the heart tissue responsible for allowing incorrect electrical signals that activate the heart muscles in a way that results in abnormal heart rhythm.

A study hypothesis was that those sites at which localized ablation eliminates persistent AF have characteristics that can be identified through activation mapping when AF occurs. With 57 patients taking part in the study, complex analysis was undertaken that revealed repetitive rotational or focal activity patterns occurring at all sites in which AF termination occurred. Not all methods were equally effective at identifying these sites. The mechanism through which local ablation has this effect is described as needing further research.