Cardiac Arrhythmias

Heartbeat out of sync

Life-threatening cardiac arrhythmias often occur after a heart attack, as the scar tissue can interfere with the spread of electrical impulses that activate the heart. An international research team under the leadership of ...

May 08, 2018
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New view of the heartbeat

The human cardiac voltage-gated sodium channel (Nav1.5) plays a critical role in maintaining regular heartbeats. Mutations in Nav1.5 cause life-threatening heart rhythm disorders (arrhythmias).

Apr 09, 2018
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Noise throws the heart out of rhythm

With an increasing level of noise, the incidence of atrial fibrillation also increases dramatically. Scientists from the Department of Cardiology at the Mainz University Medical Center were able to prove this with data from ...

May 03, 2018
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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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