Mechanisms of Atrial Flutter


 Atrial Flutter pic
Atrial Flutter

Dr. Sanjiv M. Narayan directs both the electrophysiology research program and the atrial fibrillation program at Stanford University. From 2002 to 2017, Dr. Sanjiv Narayan has published papers that analyzed cardiac rhythm patterns in patients with atrial fibrillation and flutter.

A person’s heartbeat stems from activity in the sinoatrial (SA) node, a structure located in the right atrium of the heart. The Sino-atrial node generates an impulse that travels through the heart, pausing for a moment at the atrioventricular (AV) node to allow the blood to move from the top half of the heart to the bottom.

In the case of atrial flutter, a specific organized type of abnormality develops in the pathway that the electrical impulse follows. This causes the impulse to travel in a circular motion, which makes the atria of the heart beat more rapidly than the ventricles.

A heart with atrial flutter cannot pump blood as effectively as it should. Insufficient blood flow can then cause vital organs to receive insufficient oxygen and nutrients, which may lead to organ failure. There is also a risk of heart attack, stroke, and congestive heart failure.

Atrial Fibrillation Study on Ablation and Pulmonary Veins Isolation


Atrial Fibrillation pic
Atrial Fibrillation

A respected California cardiologist, Dr. Sanjiv M. Narayan was responsible for developing new atrial fibrillation treatments that were acquired by Abbott Laboratories. Presently a Stanford University professor focused on establishing an arrhythmia center, Dr. Sanjiv M. Narayan has coauthored papers such as “Independent mapping methods reveal rotational activation near pulmonary veins where atrial fibrillation terminates before pulmonary vein isolation” (Journal of Cardiovascular Electrophysiology, 2018).

Atrial fibrillation involves the upper chambers of the heart beating irregularly, which disrupts the effective movement of blood into the ventricles. Blood clot is a common cause, and stroke can result in cases where the clot breaks off and gets stuck in the artery that leads to the brain. The procedure known as AF ablation involves carefully destroying or scarring targeted heart tissue in a way that disrupts the defective electrical signals that cause arrhythmia.

The study focused on exploring mechanisms through which, prior to pulmonary veins (PV) isolation, atrial fibrillation (AF) can be terminated in the vicinity of the PV during ablation. The study included 22 patients and found that localized rotational (‘whirlpools’) or focal activity was present at the site near the Pulmonary Veins in each case where AF was terminated by ablation. This may explain the benefit of PV ablation in AF. Through mapping such sites, PV lesion sets can potentially be tailored for each patient, and sites outside the PVs can be targeted.