Showing posts with label Left atrium. Show all posts
Showing posts with label Left atrium. Show all posts

Monday, January 1, 2024

A Pioneer; Michel Haïssaguerre

Atrial fibrillation (AF) is the most common heart rythm disorder, affecting 0.5% of the world's population and 3% of the population of Europe and North America.  According to the CDC approximately 2% of people younger than 65 years old have atrial fibrillation, while 9% of those over 65 are afflicted by AF and it is the cause of 20-25% of ischemic brain strokes.

Atrial fibrillation is treated with lifestyle changes, medicines such as beta and calcium channel blockers, anti-arrhythmics, anticoagulants and procedures such as catheter ablation in order to slow the heart rate and restore a normal heart rhythm.

In 1988, Michel Haïssaguerre a cardiac electrophysiologist in Bordeaux, France described the use of catheter ablation for patients with atrial fibrillation.  He founded that in 95% of the patients, AF episodes were caused by abnormal electrical "triggers" originating from within or the viscinity of pulmonary veins in the left atrium.  By mapping the triggers and ablating them, he was able to render 62% of patients free of AF without the need of using anti-arrhythmic drugs.  This landmark finding has led to the development of catheter ablation as a routine management strategy for atrial fibrillation.  His technique prevents this abnormal electric activity from reaching the atria  and is the sine qua non in the treatment of AF.  Although the patients may experience a return of the arrhythmia, the procedure is considered a safe, effective and minimally invasive method.  Studies have shown that the overall complication rate of cardiac ablation procedures is about 6%.

Michel Haissaguere was born in Bayonne, France on October 5th, 1955.  He became a Professor of Cardiology in 1994 and is the Chief of Cardiac Pacing and Electrophysiology Department at the Haut-Leveque Cardiology Hospital, part of the Bordeaux University.  Professor Haissaguerre was elected member of the French Academy of Sciences in 2010 and has received multiple awards such as the Best Scientist Gruntzig of the European Society of Cardiology, Pioneer of Electrophysiology of the North American Rhythm Society, the Gold Medal of the European Society of Cardiology and numerous others.  He and his associates have published more than 800 papers on this subject.  

The above post is dedicated Dr Mahmood Houmsee, an expert electrophysiologist at Ohio State. He took care of me both as an outpatient and inpatient and keeps me in good condition. Also to Dr Peter Danias who has been my cardiologist in Greece.  Dr. Danias' expertise in cardiac computed tomography and magnetic resonance imaging established these diagnostic methods in Greece.  

Sunday, June 12, 2016

Thrombi in left atrium can be detected with cardiac MRI

Kitkungvan et al report in the J Am CollCardiovascular Imaging that left atrial (LA) and left atrial appendage (LAA) thrombi can be detected with cardiac MRI (CMR) – without the need of a trans-esophageal echocardiogram (TEE) – before pulmonary vein isolation (PVI) is performed.

They studied 261 patients with congestive heart failure, hypertension, diabetes mellitus, stroke/transient ischemic attack, vascular disease, with CMR and TEE for evaluation of pulmonary venous anatomy before PVI. LA and LAA thrombi were evaluated by using CMR as follows: 1) cine-CMR; 2) contrast-enhanced magnetic resonance angiography; and 3) equilibrium phase delayed enhancement (DE) CMR with a long inversion time (TI) of 600 ms (long TI DE-CMR).

CMR and TEE were performed within 1.3 ± 2.3 days. LA/LAA thrombi were discovered in 9 patients (3.5%) by using TEE. Among the CMR techniques performed, long TI DE-CMR had the highest diagnostic accuracy (99.2%), sensitivity (100%), and specificity (99.2%), followed by contrast-enhanced magnetic resonance angiography accuracy (94.3%); sensitivity (66.7%); and specificity (95.2%) and cine-CMR accuracy (91.6%); sensitivity (66.7%); and specificity (92.5%).


The authors concluded that patients who were candidates for pulmonary vein isolation surgery, cardiac MRI with long inversion time delayed enhancement independently picked up LA and LAA clots in the same 3.5% of patients as did gold-standard TEE, thus CMR could be the single diagnostic study for assessment of pulmonary venous anatomy as well as presence of atrial thrombi thus reducing the number of pre-operative tests before PVI.