Heart Health > > Heart arrhythmia
A healthy heart functions by pushing blood through its four chambers through a sequence of rhythmic muscular contractions. An arrhythmia occurs when there is a disturbance in the sequence of contractions. These abnormal heart rhythms cause the heart to pump blood less effectively and can compromise overall heart health.
Most hearth arrhythmias are temporary and often times benign. These include times when your heart “skips a beat” or has an extra beat. These changes can be caused by exercise or extreme emotional reactions. However, some arrhythmias can be dangerous and may require treatment to maintain healthy heart functioning.
There are two categories of heart arrhythmias: ventricular and supraventricular. Ventricular arrhythmias occur in the lower ventricles of the heart, whereas supraventricular arrhythmias occur in the upper chambers. These disturbances are further classified by whether they slow or speed up the regular pumping sequence. A slowing arrhythmia is called a bradycardia, and a speeding up is a tachycardia. Fibrillations are the most serious forms of arrhythmias. These are contractions of individual heart muscle fibers and can often be fatal.
Supraventricular arrhythmias are often seen in patients with heart disease. Long-term supraventrical arrhythmias are called atrial fibrillations. These cause the heart to beat close to six times the normal beats per minute. One of the most serious risks to heart health falls under that category of ventrical arrhythmias. Long-term ventricular tachycardia involve repeated electrical impulses from the ventricles that speed up the heart and can only be stopped by drug intervention or other electrical impulses from an outside source.
Symptoms of arrhythmia include heart palpitations, feeling tired or light-headed, shortness of breath and chest pain. Symptoms of bradycardia lean toward tiredness or dizziness, while tachycardia symptoms include pulsing in the neck, racing beats and discomfort in the chest.
Heart arrhythmias can be hereditary, or they can be brought on by heart disease. Diabetes and high blood pressure, as well as high levels of caffeine, alcohol and some cold medicines can cause arrhythmias. Relaxation, limiting caffeine and nicotine intake, and stress reduction are all used to treat arrhythmias and can lead to better heart health. In some cases, drugs must be used to control the condition, and in very serious cases, pacemakers may be used to regulate the electrical impulses in the heart that maintain regular circulation of blood.
Questions and Answers: A Look at Atrial Fibrillation
Gene C. Kim, MD
The normal heart beats 60 to 100 times per minute regularly. The SA node is the heart’s electrical pacemaker that initiates the electrical impulse and determines the rate at which the heart beats. There are times when the heart may beat more slowly or quickly. There are other times the heart beats irregularly or rapidly due to atrial fibrillation.
Q: What is atrial fibrillation?
A: It is the most common type of abnormal heart rhythm in the United States affecting over 2 million people. It results in quivering, ineffective and uncoordinated contraction of the atria (upper heart chambers) at > 300 beats a minute instead of regular synchronized contractions at 60 to 100 beats per minute. The uncoordinated contractions and electrical signals are transmitted to the ventricles (lower heart chambers) in an irregular fashion usually at rapid rates. This leads to the irregular heart beats and pulse.
Q: What causes atrial fibrillation?
A: Unfortunately it has not been clearly determined. There are multiple conditions that are associated with atrial fibrillation. Some of these conditions are sinus node disease, coronary artery disease, previous heart attack, heart failure, rheumatic heart disease, pericarditis, hypertension, hyperthyroidism, binge drinking of alcohol, pulmonary embolism, sleep apnea, drug use and many other diseases.
Q: What symptoms would I experience if I have atrial fibrillation?
A: There are many patients that may be asymptomatic and are told on routine physical that they have a rhythm problem. Others may complain about palpitations (sensation of rapid heart beats), fatigue, weakness, shortness of breath, chest pain, light-headedness, and fainting.
Q: How is it diagnosed?
A: Atrial fibrillation can often be diagnosed by your primary care physician with a physical examination. Using a stethoscope, an irregular heart rhythm may be heard or the pulse can be checked for irregularity. Besides physical examination, an electrocardiogram (ECG) can easily provide the diagnosis of atrial fibrillation if present at the time of recording. In some patients with intermittent, paroxysmal atrial fibrillation, the ECG may be normal during the office or hospital visits. A Holter monitor, 24 continuous heart rhythm monitor, or an event monitor, a patient activated device at time of palpitations, may be able to document the atrial fibrillation.
Q: What are the long term risks of atrial fibrillation?
A: With atrial fibrillation and the quivering of the atria, there can be stasis or pooling of the blood. The stagnant blood can form blood clots within the atria. These clots can dislodge and enter the circulation traveling to the heart, brain, lungs, or other parts of the body. This can lead to a heart attack, stroke, and injury to the lungs, kidneys, hands, or feet. This can be a serious, debilitating complication. This can be minimized through the use of anticoagulants in the appropriate patients.
Also with atrial fibrillation the heart is often not pumping as efficiently as in normal rhythm. This can lead to heart failure and symptoms of shortness of breath, leg swelling, and weight gain from the retention of water. When atrial fibrillation causes rapid sustained heart beats for an extended period of time, it can cause weakening of the heart muscle (tachycardia induced cardiomyopathy).
Q: How do I treat it?
A: The treatment targets 1) the underlying or associated diseases that may contribute to atrial fibrillation 2) slowing the heart rate 3) restoring normal heart rhythm with medications or electrical cardioversion 4) preventing strokes with the use of anticoagulants, “blood thinners.” 5) procedures to prevent atrial fibrillation (surgery, catheter based ablation, pacemakers, and atrial defibrillators)
Q: Can it be cured?
A: There are surgical approaches that can cure atrial fibrillation. The surgical Maze procedure entails open heart surgery and going on a bypass pump. Given the risks and extent of the surgery it is usually done in conjunction with other heart surgeries. There are newer minimally- invasive surgical approaches (“mini-Maze”) which go in between the ribs and do not require going on a bypass pump.
Percutaneous catheter based ablation is directed at eliminating the initiators of atrial fibrillation or modifying the left atrium to prevent the initiation and maintenance of atrial fibrillation. It is less invasive than the surgical approach. It is performed in the cardiac electrophysiology laboratory. The procedure typically takes three to four hours and patients go home the following day after overnight observation. Catheters are introduced into the heart via the femoral (groin) vein under local anesthesia as well as conscious sedation (relaxed and sleepy but breathing on your own). The areas that are contributing to atrial fibrillation are ablated using radiofrequency energy. With the destruction of the tissue it is no longer able to initiate or maintain atrial fibrillation. It does not affect the normal functioning of the atria. Unfortunately, since the definitive cause for atrial fibrillation is still unknown, the definitive cure has been elusive. The ablation is not 100% successful. The results need to be individualized but patients can expect about 70% to 85% success rate. Some may need continued medications or a repeat ablation procedure.
Candidates for ablation are 1) patients with chronic sustained atrial fibrillation or paroxysmal, intermittent atrial fibrillation 2) patients with recurrent, symptomatic atrial fibrillation while on medications 3) patients intolerant to the side effects of long-term medications 4) patients who do not wish to continue taking long-term or anti-coagulation medications.