Some abnormal heart rhythms can happen without the person knowing it, while some may cause the feeling of the heart “racing,” lightheadedness, or dizziness. At some point in life, many adults have had short-lived heart rhythm changes that are not serious.
Certain heart rhythms, especially those that last long enough to affect the heart’s function, can be serious or even deadly.
Palpitation or Skipped Beat
Although it may seem as if the heart missed a beat, it has really had an early heartbeat — an extra beat that happens before the heart has a chance to fill with blood thereby resulting in a pause.
A fluttering sensation (like butterflies in the chest) is usually due to extra or “skipped beats” that occur one right after the other, or may be caused by other kinds of abnormal heart rhythms.
Slow Heartbeat – Bradycardia
If the heartbeat is too slow (usually below 60 beats per minute), not enough blood carrying oxygen flows through the body.
The symptoms of a slow heartbeat are:
Fatigue (feeling tired)
Dizziness (spinning sensation)
Fainting or near fainting
Rapid Heartbeat – Tachycardia
When the heart beats too quickly (usually above 100 beats per minute), the lower chambers, or ventricles, do not have enough time to fill with blood, so they cannot effectively pump blood to the rest of the body.
The symptoms of a rapid heartbeat are:
Skipping a beat
Beating out of rhythm
Fast heart beat or racing heartbeat
Shortness of breath
Fainting or near fainting
Chaotic, quivering or irregular rhythm
Sudden rapid, irregular and chaotic heartbeats may be a sign of a common heart rhythm problem called atrial fibrillation (AFib). Rarely, passing out, or fainting, may be caused by the most dangerous arrhythmia, ventricular fibrillation (VF). VF is the number one cause of sudden cardiac death. Within seconds, the person loses consciousness and, without immediate emergency treatment, will die within minutes.
Almost Fainting – Presyncope
Sometimes people have symptoms before they faint. Presyncope can be a sign of a heart rhythm disorder and should be evaluated carefully.
Dizziness, lightheadedness, or vertigo (spinning)
Blurred or narrowed (tunnel) vision
Nausea (feeling sick in the stomach) and/or vomiting
Confusion and/or difficulty speaking clearly or coherently (not making any sense)
Fainting – Syncope
Fainting from a heart rhythm disorder is more likely to happen suddenly and without warning than fainting from other causes, such as dehydration or low blood sugar. Any sudden loss of consciousness should be evaluated by a doctor. In some cases, fainting is the only warning sign of a dangerous heart rhythm that could cause sudden cardiac death.