A normal heartbeat begins in the right atrium (upper chamber of the heart). There the sinus node acts as a natural pacemaker and sends an electrical signal. The signal spreads throughout the upper chambers of the heart to the atrioventricular node between the upper chambers. From there, the electrical signal travels to the ventricles (lower chambers of the heart).
As the signal travels through the heart, the upper chambers contract, pumping blood into the lower chambers. The lower chambers of the heart then contract, sending blood throughout the body. The Institute for Cardiac Rhythms at Aurora St. Luke's Medical Center is home to electrophysiologists who have specialized training in the electrical forces that cause the heart to beat.
Heart rhythm disorders are also known as arrhythmias. The heart may seem to skip a beat or briefly beat too slowly or too rapidly. There are a variety of
arrhythmia types. Sometimes the heartbeat begins in another part of the heart instead of the sinus node. Sometimes the sinus node develops an abnormal rhythm or rate. Or the electrical signal may be interrupted or blocked from passing to the lower chambers of the heart. Some heart rhythm disorders are more serious than others.
Atrial flutter: occurs when muscles in the upper chambers of the heart contract quickly, leading to a very fast, steady heartbeat; caused by rapidly fired electrical signals.
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Atrial fibrillation: a completely irregular heartbeat caused by electrical signals fired in a very fast and uncontrolled manner.
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Bradycardia: a very slow heartbeat that may result in the heart stopping completely if not treated.
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Paroxysmal atrial tachycardia: related to superventricular tachycardia; involves repeated periods of very fast heartbeats that begin and end suddenly.
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Premature supraventricular contractions or premature atrial contractions:
a heartbeat occurs early in the upper chambers of the heart, causing the heart to beat prior to the next regular heartbeat.
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Premature ventricular complexes: an early heartbeat is caused by an electrical signal from the lower chambers of the heart and then the heart seems to pause until the next regular heartbeat.
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Sick sinus syndrome: the heart rate slows down and may alter between a slow or fast rate because the sinus node does not fire electrical signals properly.
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Sinus arrhythmia: cyclic changes in the heart rate during breathing.
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Sinus tachycardia: a fast heartbeat due to faster-than-normal electrical signals from the sinus node.
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Superventricular tachycardia: the heart rate speeds up because of a series of early beats in the upper chambers of the heart.
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Ventricular fibrillation: the heart quivers instead of beating and pumping blood because electric signals fired in the lower chambers of the heart are very fast and uncontrolled.
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Ventricular tachycardia: a fast heartbeat due to electrical signals from the lower chambers of the heart.
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Wolff-Parkinson-White syndrome: very fast heart rate resulting from electrical signals that pass along abnormal pathways between the upper and lower chambers of the heart.
