Cardiac Arrhythmias: Symptoms, Causes, Diagnosis, and Treatment
Cardiac arrhythmias can produce a range of symptoms, from very mild (or even none) to life-threatening. These symptoms can be divided into a “classic” group of symptoms that should make a doctor look specifically for a cardiac arrhythmia as the likely cause and an “other” group of symptoms that are just as likely to be caused by other medical conditions.
Many people who are diagnosed with a cardiac arrhythmia will express surprise that they have experienced no symptoms. However, it is the case that many times cardiac arrhythmias may not produce any symptoms at all. This is especially true for arrhythmias that produce intermittent “extra” heart beats—premature atrial complexes (PACs) and premature ventricular complexes (PVCs).Others may experience these classic symptoms.
If a cardiac arrhythmia is preventing the heart from pumping blood sufficiently to provide the body’s needs, episodes of lightheadedness may result. When an arrhythmia is producing lightheadedness, it is more likely to do so when you are upright, or when you are doing something active. Resting or lying down tends to improve this symptom.Lightheadedness is a common symptom that has many potential causes in addition to arrhythmias. But when an arrhythmia produces lightheadedness, it is a sign that the arrhythmia itself may be dangerous, and may lead to even more severe problems such as syncope or even cardiac arrest.Because lightheadedness may be a sign of a potentially dangerous problem, this is a symptom that should never be ignored, but should always be evaluated by a physician.
A cardiac arrest occurs when a persistent, severe cardiac arrhythmia stops the flow of blood to the brain for a prolonged period of time. The difference between an arrhythmia that produces syncope and one that produces cardiac arrest is simply how long the arrhythmia persists.While severe bradycardia may cause a cardiac arrest, most often this condition is produced by ventricular fibrillation or ventricular tachycardia. Cardiac arrest invariably leads to rapid death (and is the main cause of sudden death), unless either the arrhythmia terminates by itself, or effective cardiopulmonary resuscitation is administered within a very few minutes.Anyone who has survived a cardiac arrest should be considered to be at high risk for subsequent episodes of cardiac arrest and should receive aggressive and effective therapy. Most of these people will be strong candidates for an implantable defibrillator.
In addition to these classic symptoms, cardiac arrhythmias may also produce several less specific, more generalized symptoms that may not necessarily point a doctor toward considering an arrhythmia as the cause.Most of these “other” symptoms are related to an arrhythmia causing a relative reduction in the ability of the heart to pump blood to the body’s organs. These symptoms are more likely to occur when a person is upright or exerting him/herself; and in people who have other medical conditions in addition to the arrhythmia, such as heart failure, diabetes, lung problems, or coronary artery disease.
These symptoms include:
- Generalized weakness
- Dyspnea (shortness of breath)
- Poor exercise tolerance
- Chest pain
When to See a Doctor
Any of these symptoms should prompt a visit to the doctor. An episode of severe lightheadedness or unexplained syncope should be evaluated immediately, and warrants a call to 911.
Arrhythmia Doctor Discussion Guide
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