What causes an arrhythmia?
The heart has 4 compartments, or chambers. The walls of the heart squeeze together (contract) to push blood through the chambers. The contractions are controlled by an electrical signal that begins in the heart's natural "pacemaker" (called the sinoatrial node). The rate of the contractions is influenced by nerve impulses and hormones in the blood. A problem in any of these can cause an arrhythmia.
The most common symptom of arrhythmia may be palpitation but different individuals experience the symptoms of arrhythmia differently. Some who have this condition may not feel any symptoms. In these patients, their arrhythmia will go unnoticed until it is detected by a physician during a routine examination. Others may experience only minor symptoms, while some are sensitive to the slightest sensation. Symptoms commonly reported include:
- Shortness of Breath
- Syncope (Fainting)
- Chest Pain
The heart's electrical system generates impulses that are felt as heartbeats. It is normal to have occasional premature beats that can occur under normal conditions as every cell in the heart muscle is capable of initiating an electrical impulse. However, if you have rapid or irregular heartbeats, this can cause a sensation called palpitation. Palpitation can be perceived differently in different people. Most patients describe palpitations as a feeling of a more forceful beat but some patients describe palpitation as fullness in the throat or neck. They are often felt at times when the mind and body are relaxed, so patients often experience palpitations in the evening when reading, watching television, or getting into bed. Patients may also experience palpitation during exercise or just after completing exercise or even after eating spicy food, chocolate, or caffeinated beverages. Feeling palpitations often causes additionally anxiety that can produce increased adrenaline levels, which, in turn, can increase the frequency of the premature beats and make the palpitations worse. Although palpitations can be a benign condition, they should always be evaluated by a cardiologist to rule out any underlying problems.
Some arrhythmias may cause syncope (fainting), lightheadedness, or dizziness. This is caused by the heart either beating too slow or too fast, leading to an insufficient flow of blood to the brain or to low blood pressure. Syncope can be episodic and difficult to diagnose. A tilt table test may be recommended to determine if the cause of recurrent fainting spells is due to neurocardiogenic syncope. Arrhythmia Associates also offer a 24-hour monitor (Holter), a 30-day event monitor and also implantable diagnostic device that provides a method for the diagnosis of syncope or lightheadedness.