Why Does the Heart Beat Irregularly? Understanding Arrhythmias
A clear explanation of abnormal heart rhythms, why they happen, and how doctors diagnose and treat arrhythmias
When the Heart’s Rhythm Suddenly Changes
Michael is sitting in the emergency department describing a strange sensation in his chest. He says it feels like his heart is fluttering, then racing, then pausing.
For a few seconds he feels lightheaded.
By the time he arrives at the hospital the feeling has already passed. But moments like this often point toward a problem with the heart’s electrical rhythm.
What an Arrhythmia Actually Is
An arrhythmia is an abnormal heartbeat.
In a healthy heart, electrical signals travel through a specialized pathway that coordinates each beat. These signals tell the heart muscle when to contract, creating a steady and predictable rhythm.
When this electrical system becomes disrupted, the heart may beat too fast, too slow, or in an irregular pattern. Any abnormal rhythm of this type is called an arrhythmia.
When the Heart Beats Too Fast or Too Slow
Arrhythmias can affect the speed of the heartbeat.
If the heart rate becomes unusually slow, doctors call it bradycardia. If it becomes too fast, it is called tachycardia. Both conditions can interfere with the heart’s ability to pump blood effectively.
Sometimes the rhythm is not just fast or slow, but irregular. Instead of the normal steady pattern of beats, the heart may skip beats, flutter, or beat chaotically.
Some Arrhythmias Are More Dangerous Than Others
Not all abnormal heart rhythms carry the same level of risk.
Some rhythms are relatively mild and may cause only brief symptoms such as palpitations or dizziness. Others can interfere with blood flow to the brain or other organs.
Examples include atrial fibrillation, ventricular tachycardia, and ventricular fibrillation. These rhythms can significantly disrupt circulation and sometimes require urgent medical treatment.
How Doctors Detect an Arrhythmia
The most important test for diagnosing an arrhythmia is an electrocardiogram, often called an EKG.
An EKG records the electrical activity of the heart and allows doctors to see exactly how the rhythm is behaving. Blood tests may also help identify electrolyte problems that can trigger abnormal rhythms.
Sometimes patients wear portable heart monitors that record heart rhythm over longer periods, especially if the symptoms occur intermittently.
How Arrhythmias Are Treated
Treatment depends on the type and cause of the abnormal rhythm.
Some arrhythmias improve once underlying issues such as dehydration or electrolyte imbalances are corrected. Others may require medications that help stabilize the heart’s electrical signals.
In more serious cases, procedures such as electrical cardioversion, catheter ablation, or implanted devices like pacemakers may be used to restore a stable rhythm.
THE BOTTOM LINE
• An arrhythmia is an abnormal heart rhythm that causes the heart to beat too fast, too slow, or irregularly
• Symptoms may include palpitations, dizziness, fainting, or shortness of breath
• Doctors diagnose arrhythmias using tests such as EKGs and treat them based on the specific rhythm and underlying cause
By Dr. Karim Ali, Emergency Physician