by Mark | Aug 28, 2019 | Cardiac Electrophysiology, Cardiology, General Public, Science
I am excited to announce that work from our laboratory was recently published in Circulation: Arrhythmia and Electrophysiology, as an Editor’s Choice Article. In this work, we show for the first time that the native electrical signal in the heart can be transferred from one region to another with a surgical suture made from carbon nanotube fibers (CNTf). The CNTf sutures have remarkable electrical conductivity, strength, and flexibility and are the first to be used in surgical applications to restore electrical conduction in the heart. The long-term impact of this work is that the reestablishment of cardiac conduction has the potential to revolutionize therapy for cardiac electrical disturbances, one of the most common causes of death in the United States. Link to the article can be found here: In Vivo Restoration of Myocardial Conduction with Carbon Nanotube Fibers. News media coverage can be found here: Physics World, Nanotechnology News, Phys.Org, Today’s Medical...
by Mark | Dec 13, 2015 | Cardiac Electrophysiology, Cardiology, General Public
What is AVNRT? Rapid beating of the heart can cause the sensation of palpitations, which are often described as fluttering, pounding, and beating sensations in the chest. Sometimes these palpitations are rapid enough to affect other parts of the body, and people with palpitations may also describe feelings of lightheadedness, fatigue, and shortness of breath. Occasionally, these palpitations are rapid enough to cause people to pass out (syncope), though this is rare. Rapid palpitations may come from the heart’s upper chambers, the atria, and in most cases, are not generally considered life threatening (although rare exceptions do exist). Alternatively, palpitations may come from the heart’s lower chambers, the ventricles, which in some cases may be life-threatening. Also, the natural electrical “bridge” between the atria and ventricles, the atrio-ventricular (AV) node, can be a common site of arrhythmias causing palpitations. The best way to start the diagnosis of the cause of palpitations is to have an electrocardiogram (ECG) read by a physician experienced in heart rhythm disorders. Supraventricular tachycardia (SVT) is a category of arrhythmias that come from above the ventricles. The most common type of regular SVT is AtrioVentricular Nodal Reentrant Tachycardia (AVNRT), and is responsible for 50% of SVT cases (1). AVNRT is more common in women than men, and typically occurs in patients between 20 and 40 years old. This long, descriptive arrhythmia name details the biology of the abnormal electrical circuit within the heart that leads to the palpitations that are commonly described. In AVNRT, there is a small circular (Reentrant) electrical circuit that “spins” around in the AV node, the normal, natural electrical bridge between the atria and ventricles....
by Mark | Sep 8, 2015 | Cardiac Electrophysiology, Cardiology, General Public
What is atrial tachycardia? Atrial tachycardia (AT) is a disorder of fast heart rhythm that begins in the upper chambers of the heart, the left and right atria (1). AT can start from one area, or focus, in either atrium and is called focal AT. AT can also arise from multiple different areas of the atria, and is called multifocal AT. Regardless the mechanism (focal vs. multifocal), the extra early signals that start from the focus/foci spreads centrifugally out to affect the atria and ventricles, and thus speeds up heart rate. The racing heart may be felt by the patient as palpitations, dizziness, chest pain or lightheadedness, or in some people may be asymptomatic (2). Occasionally, fast AT seen in younger patients can cause them to pass out. AT has two unique characteristics that distinguish it from other similar atrial rhythm disorders: 1) they often occur in repetitive short bursts, and 2) AT episodes exhibit “warm up” and “cool down” periods where rate varies at initiation and termination of the arrhythmia (1). Although short bursts of AT are common, sustained AT is a more rare cause of sustained arrhythmias from the atria (supraventricular tachycardia, SVT). Of all episodes of SVT encountered by electrophysiologists, AT is the cause only about 5-15% of the time (2-3). The diagnosis of AT is usually straightforward and starts with a thorough medical history and physical examination. If the patient is exhibiting AT during the exam, then an electrocardiogram (ECG) may demonstrate a fast heart rhythm consistent with AT. Cardiologists would recognize AT on the ECG as 1:1 P-QRS coupling, with non-sinus P-wave morphology, and usually long R-P...
by Mark | Aug 29, 2015 | Cardiac Electrophysiology, Cardiology, General Public
What is Atrial Fibrillation? Atrial fibrillation is the most common sustained arrhythmia in the human heart (1). In the United States today, over 5.6 million patients have been diagnosed with atrial fibrillation and this number is growing; by the year 2030 it is estimated that this diagnosis will extend to 12.1 million Americans (2). Atrial fibrillation is a disease of rapid, chaotic electrical activity in the upper chambers of the heart, the left and right atria (3). Normally, each heartbeat starts in the normal, natural pacemaker of the heart, the sinoatrial (SA) node which lies in the right atrium. A normal heartbeat depends on an electrical wave that begins in the SA node and travels out from this node to first cover both atria, then traverses the AV node, which is a bridge to the ventricles, and finally to the ventricles, the main pumping chambers of the heart. When atrial fibrillation starts, rapid irregular electrical signals occur in the atria apart from the SA node and “take over” the heart rhythm from the top down. In other words, these rapid chaotic electrical impulses suppress the normal “sinus” rhythm of the heart, and create a chaotic irregular heart rhythm. One analogy for atrial fibrillation is a fireworks show. If you were listening to your favorite song, and really wanted to focus listening to the song’s rhythm, it would be simple if you were sitting in your room quietly with your headphones on. However, try listening to the rhythm outdoors at a fireworks show, for example on the 4th of July, and it would be an entirely different experience. The rapid chaotic...
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