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.  

Risk of Stroke due to Intracranial Atherosclerosis

Bos et al report in JAMA Neurology on the relationship between intracranial carotid artery calcifications and the risk of stroke in white populations.  As 80% to 90% of all strokes are due to acute ischemic strokes (AIS), it is important to recognize that atherosclerosis varies across the vascular beds and as such, different locations of vascular disease may have important role in AIS pathogenesis.  Atrial fibrillation and large-artery atherosclerosis such as in aortic arch and extra-cranial carotids are recognized as a major risk factors for AIS.  How common strokes occur after occlusion of the small intra-cerebral arteries, in so-called cerebral small-vessel disease is not well understood.

Between the years 2003 and 2006, a random sample of 2323 stroke-free persons (mean age, 69.5 years) underwent computed tomography scanning to quantify intracranial carotid artery calcification burden.  The population-based cohort was from the general community and part of the Rotterdam Study. All participants were continuously monitored for the occurrence of stroke until January 1, 2012.

During 14 055 person-years of follow-up, 91 participants had a stroke, of which 74 were acute ischemic strokes.  Large intracranial carotid artery calcification burden was related to a higher risk of stroke, independent of cardiovascular risk factors, ultrasound carotid plaque score, and calcification in other vessels.  Intracranial carotid artery calcification contributed to 75% of all strokes; for aortic arch and extra-cranial carotid artery calcification this incidence was only 45% and 25%, respectively.  As the sum of risk factors for strokes exceeds 100%, it suggests interaction between them as well as that unknown causes may contribute to AIS.

The findings of their study establish intracranial atherosclerosis as a major risk factor for stroke in the general white population and suggest that its contribution to the number of all acute ischemic strokes may be greater than atherosclerosis in common and internal carotid arteries as well as that from the arch of the aorta.