Cardiac Arrhythmias

New insights into sodium channel structure

Northwestern Medicine scientists have mapped the complete structure of a voltage-gated sodium channel, proteins in the membrane of cells that play an important role in many diseases. The findings were published in Nature ...

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Requirements for AEDs in US schools need improvement

Automated external defibrillators are associated with increased survival of sudden cardiac arrest when installed in schools, yet only 17 out of 50 U.S. states require AED installation in at least some of their schools, according ...

Mar 27, 2017
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Noninvasive imaging helps predict heart attacks

Noninvasive CT angiography and stress tests can help predict which patients are likely to suffer a heart attack or other adverse cardiovascular event, according to a new study appearing online in the journal Radiology.

Mar 14, 2017
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Heart palpitations should not be ignored

Does the sight of your loved one make your heart skip a beat … literally? Well, that may not be a good thing. Doctors at Baylor College of Medicine say while heart palpitations are common, they should not be ignored.

Feb 07, 2017
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Cardiac dysrhythmia (also known as arrhythmia and irregular heartbeat) is any of a large and heterogeneous group of conditions in which there is abnormal electrical activity in the heart. The heart beat may be too fast or too slow, and may be regular or irregular.

Some arrhythmias are life-threatening medical emergencies that can result in cardiac arrest. Others cause symptoms such as an abnormal awareness of heart beat (palpitations), and may be merely annoying. These palpitations have also been known to be caused by atrial/ventricular fibrillation, wire faults, and other technical or mechanical issues in cardiac pacemakers/defibrillators. Still others may not be associated with any symptoms at all, but may predispose the patient to potentially life threatening stroke or embolism.

Some arrhythmias are very minor and can be regarded as normal variants. In fact, most people will on occasion feel their heart skip a beat, or give an occasional extra strong beat; neither of these is usually a cause for alarm.

Proarrhythmia is a new or more frequent occurrence of pre-existing arrhythmias, paradoxically precipitated by antiarrhythmic therapy, which means it is a side effect associated with the administration of some existing antiarrhythmic drugs, as well as drugs for other indications. In other words, it is a tendency of antiarrhythmic drugs to facilitate emergence of new arrhythmias.

The term sinus arrhythmia refers to a normal phenomenon of mild acceleration and slowing of the heart rate that occurs with breathing in and out. It is usually quite pronounced in children, and steadily decreases with age. This can also be present during meditation breathing exercises that involve deep inhaling and breath holding patterns.

This text uses material from Wikipedia licensed under CC BY-SA

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