The heart is an amazing organ, beating an average of 100,000 times per day to pump blood throughout the body. The precise timing and contraction of the heart is mainly due to an electrical pathway starting from the top chambers of the heart (atria) to the lower chambers (ventricles). In some individuals, an accessory pathway is present resulting in early contraction and abnormal heart rhythms. This rare condition is called Wolff-Parkinson-White Syndrome and occurs in approximately one in every thousand individuals, according to the Genetics Home Reference.
Identification
Wolff-Parkinson-White Syndrome (WPW), a condition in which an extra conduction pathway is present in the heart, is a one type of "pre-excitation syndrome." The condition is linked to a genetic mutation in most cases and is present at birth. In WPW, the extra electrical impulse that causes the heart to contract, reaches the ventricles too soon. The condition is generally non-life-threatening, effectively treated and often presents with no symptoms.
Symptoms
A rapid heart rhythm, a condition called tachycardia, is the most common symptom of Wolff-Parkinson-White Syndrome. This often leads to feelings of chest tightness and pain as well as palpitations. Other symptoms include dizziness, shortness of breath, low blood pressure (hypotension), fainting and light-headedness. However, the condition often causes no problems or symptoms, depending on the individual.
Complications
Several complications can arise from an abnormal heart rhythm and conduction system, especially if other heart conditions are present in the individual. Cardiac arrest and sudden death are possible as well as heart failure, in which the heart has problems in pumping blood to the rest of the body. Rapid heart rates can progress to a condition called atrial fibrillation, which can lead to shock. Surgery is always a risk, and complications can arise from the surgical procedures often required for treatment of Wolff-Parkinson-White Syndrome.
Diagnosis
The normal heart rate is in the range of 60 to 100 beats per minute for adults and less than 150 for infants and children. In individuals with tachycardia, the heart beats at a rate greater than 230 beats per minute. To determine where and how the abnormal conduction system is wired in the heart, an intracardiac electrophysiology study (EPS) is done. In this invasive procedure, wire electrodes are placed in the heart to map out abnormal circuits. Other tests that can identify the presence of WPW syndrome include an abnormal pattern on an ECG (electrocardiogram) and monitoring of the heart's rhythm for 24 to 48 hours with a Holter monitor.
Treatment
Treatment is generally not required in individuals with Wolff-Parkinson-White Syndrome. However, treatment options do exist including medications and surgical procedures. Medications include antiarrhythmics to control tachycardia, but they are not always effective. When medications provide no relief, radio frequency or catheter ablation procedures are recommended and generally cure the syndrome in 85 to 95 percent of cases, according to the National Institute of Health. These procedures involve interrupting and destroying the abnormal electrical pathway using the energy from a radio-frequency pulse at the end of a catheter inserted near the tissue of the heart.
