Wolff Parkinson White Syndrome, or WPW Syndrome, is an unusual genetic condition that can cause heart rhythm problems and in rare cases even sudden cardiac death. Patients with WPW are born with an abnormal electrical pathway in the heart that creates an electrical “short circuit,” which makes them prone to sudden rapid heart rhythm disturbances (tachycardia).
The Heart’s Electrical System
Most people think in terms of plumbing when they think of the heart. The plumbing system of the heart includes the coronary arteries, which can sometimes be narrowed with cholesterol-laden plaques (“blockages”). However, the heart also has an electrical system that controls the heart’s rhythm. Any rhythm disturbance (“arrhythmia”) arises from abnormal functioning of the electrical circuits of the heart.
Each normal heartbeat is generated by a structure called the Sinus Node. The sinus node is located at the top of the right atrium. It “fires” or generates an electrical signal that starts each normal heartbeat. That electrical signal spreads across the top chambers and stimulates the atria to contract. The electrical signal of the atrium then passes through an electrical connection between the top and bottom chambers. This connection is called the AV (atrioventricular) Node. The AV node allows the top and bottom chambers to work together and maintains efficient pumping of the blood.
In WPW syndrome, a person is born with an extra electrical connection that bridges the heart’s upper and lower chambers. Sometimes that extra connection, known as an “Accessory Pathway,” causes the electrical signals of the heart to look abnormal. We can see this very characteristic abnormality on an electrocardiogram (ECG or EKG).
People with this extra pathway are prone to developing rapid heartbeats (tachycardia) because the signal that controls the heart rhythm can get stuck chasing it’s own tail around and around in a circle, usually going down the AV node to the ventricles and then going up the accessory pathway back to the atrium, which allows the signal to go back down the AV node again, thus completing the circuit.
Sometimes this accessory pathway does not conduct the electrical signal from the atria to the ventricles and the ECG may look normal. However, the pathway may be able to conduct upwards from the ventricles to the atria, so that tachycardia can still occur. In that case, because the ECG is normal, it is known as a “concealed” accessory pathway. This is not the same as WPW but it can still cause the same type of tachycardia.
Rarely, the accessory pathway is capable of conducting signals very rapidly from the atria to the ventricles – at rates that are faster than the AV node itself. In that case, if the patient develops atrial fibrillation, the ventricular rate can become very fast because the signals fly rapidly down the accessory pathway to the ventricle, sometimes with rates approaching 300 beats per minute. Such a rapid heart rate can cause the heart to stop pumping properly and can lead to fainting, collapse and even sudden death. A certain number of young athletes die each year during competitive sports such as basketball or soccer because of undiagnosed WPW Syndrome.
Some people have the extra electrical pathway but don’t have any tachycardia. When this is the case, the condition is referred to as “Wolff Parkinson White Pattern” instead of being designated as a syndrome.
The WPW condition may be due to an abnormal gene, and can sometimes appear in conjunction with other types of congenital heart disease, such as Ebstein’s anomaly, a rare heart valve defect. On the other hand, it may be related to how the heart developed while the person was a fetus in the uterus.
Symptoms of Wolff Parkinson White Syndrome
WPW Syndrome is usually benign, but some people can have serious symptoms from the syndrome, including fainting, and in very rare cases, sudden death. This is why getting tested by a doctor is critical if you think you might have Wolff Parkinson White Syndrome.
Typical symptoms of WPW include:
- Sudden, rapid heart palpitations
- Dizziness or Fainting
- Shortness of breath
- Feelings of anxiety
If you have serious symptoms, such as fainting, difficulty breathing, or chest pain, then you should see a doctor immediately.
Wolff Parkinson White Syndrome Diagnosis
The typical symptom from the tachycardia of WPW Syndrome is rapid, regular heart palpitations that start suddenly, last from minutes to hours, and then stop suddenly. The tachycardia may occur rarely, like once a year, or may occur frequently. The palpitations may stop on their own, but sometimes patients have to go to an emergency room to receive medications directly into a vein to get the rapid heartbeat to stop. In some cases, exercise can trigger the tachycardia, but often it may occur for no obvious reason. An ECG is usually all that is needed to confirm the diagnosis of Wolff Parkinson White Syndrome.
You may also be asked to wear a heart monitor, which is a portable ECG that you can wear at home throughout the day for a period of time, between 24 hours and 30 days. Nowadays, there are devices you can purchase on your own that will allow you to record your own heart rhythm any time you want using a “smart phone.” Sometimes those devices are very useful if you are trying to “catch” a tachycardia that occurs very infrequently but lasts long enough to record using this pocket-sized device.
Ultimately, the best way to assess the cause of a tachycardia and determine if you definitely have WPW is through “electrophysiological testing.” This is a procedure that involves the insertion of tiny wire catheters into a vein while you are sedated. The wires are guided towards the heart and make electrical contact with the electrical system of your heart. It’s almost like doing an ECG from the inside. This painless, safe test is used to map out the heart’s electrical impulses and determine the presence and location of the abnormal pathway.
Wolff Parkinson White Syndrome Treatment Options
If you have symptoms from Wolff Parkinson White Syndrome, you have a variety of treatment options, depending on the severity of the condition.
1. Catheter Ablation
Catheter ablation is the preferred method to treat patients with WPW Syndrome who have significant symptoms. It provides a cure, with better than 96% success rate and minor complication rates in the range of 1-2%. It is considered the “gold standard” of treatments as it directly eliminates the accessory pathway, essentially restoring a normal electrical system and eliminating WPW permanently.
The procedure is performed by a cardiac electrophysiologist (heart rhythm specialist), and is generally done with enough sedation that the patient does not remember much. Electrophysiologic testing is first performed to confirm the presence and location of the abnormal pathway. One of the wire catheters is then placed on top of the pathway and electrical energy (or, rarely, freezing) is used to damage the pathway and eliminate the short circuit. The procedure takes about 2-3 hours and patients can resume their normal activities within a day or two.
Medications play a secondary role in the treatment of WPW and are reserved for patients who are not good candidates for or refuse to consider an ablation. The medications are designed to slow the electrical system down and reduce the chances of tachycardia. Unfortunately, all medications have potential side effects, and none work 100% of the time, so patients may still have symptoms even on medical therapy. Besides, any benefit of the medications is only temporary, as the problem returns as soon as the medicine is stopped. They can be used temporarily while the patient considers having an ablation.
3. Vagal Maneuvers
Vagal maneuvers are physical things that a patient can do to get a tachycardia to stop. They can sometimes work in the first minute or so of a tachycardia. The vagus nerve is part of the autonomic nervous system and helps to control the heart’s electrical system, and vagal maneuvers are designed to increase the firing of the vagus nerve to slow and hopefully stop the tachycardia. The vagus nerve carries impulses of the parasympathetic nervous system (our “rest and digest” function, as opposed to “fight or flight”). Once the tachycardia really gets going, vagal maneuvers may not work. In patients who have mild symptoms that only occur rarely, vagal maneuvers (if effective) may be the only treatment needed.
Vagal maneuvers can be taught and demonstrated by a doctor before being done at home. Some vagal maneuvers include coughing, holding the breath and bearing down (as if you are trying to move your bowels), or splashing ice cold water on the face.
4. Lifestyle Adjustments
Reducing alcohol and caffeine intake can help reduce the minor arrhythmias that serve to trigger a tachycardia. Of course, an overall healthy lifestyle with plenty of quality food and regular exercise will always support better heart health. If you have been diagnosed with Wolff Parkinson White Syndrome, you should always check with your doctor before starting a new exercise program.
Wolff Parkinson White Syndrome Can Be Overcome
Having Wolff Parkinson Syndrome is not fun, though it is usually not life-threatening. In most cases it can be cured completely. For some people with this type of electrical short circuit, the symptoms may be mild or don’t occur at all, and in that case perhaps nothing needs to be done. However, anyone with WPW should not engage in competitive sports without speaking to a specialist because of the potential risk of sudden death. Check with your doctor to discuss Wolff Parkinson White Syndrome treatment options.