Wolfe-Parkinson-White Syndrome

Ethan's 2nd Cardiac Diagnosis

The day before Ethan was scheduled to be sent to the PCU side of the NICU (parent care unit) he had an episode of SVT, supraventricular tachycardia. It was during morning lab rounds, and after he had been heel stuck for the millionith time, his heart rate raced and went well into the 180's. He wouldn't convert back to a normal heart rate without using drugs to do it. After that episode, the cardiologist ordered an ECG-electrocardiogram-which confirmed that he had Wolfe-Parkinson-White syndrome.

Dr. Kaine explained that over time WPW kids fall into one of three categories.

1/3 of all kids with WPW grow out of the episodes around a year of age

1/3 will continue to have some episodes, but are easily controlled with low doses of medicine

1/3 of kids will require RAF (radiofrequency ablation) of the extra electrical pathway causing the continued, rapid beating of the heart.

*RAF is not usually done until well into the teen years of a child-sometimes even older-and usually only if the person experiences no other relief of episodes

We were also told that kids with other CHD's like ToF usually do not also have WPW, that it is most often found by accident in otherwise healthy children. Leave it to Ethan! He was started on propranolol, a drug that is a beta-blocker, used to lower blood pressure.

Ethan outgrew his dose by 5 months of age, and his ECG at that time actually showed no more sign of the sydrome, but his cardiologist felt it beneficial to leave him on the medicine until after his ToF repair.

Update: February 2008

Ethan remained stable on the Inderal, and actually never has had another episode of tachycardia. Prior to his surgery prep he had a cardiac cath (April 2005) and his ECG at that point showed no more signs of WPW-he must have been in the third that just 'grows out of it'!! We were ready to stop his medicine, but since he was due for his open heart in June the surgeons and Cardiologist felt it would be more beneficial for him to remain on it until his follow up after the surgery. During open heart surgery the surgeons are near the electrical center of the heart-and since it is not visible there is always the chance they can interfere with it and cause some problems, which is why most children come out of surgery with pacemaker wires attached in case they need to be used for post surgical pacing and just to be proactive against having any issues-Ethan stayed on the Inderal. At his f/u cardiology appt after surgery Dr. Kaine gave us the OK to stop the Inderal -which we were happy to do!!! Ethan's f/u ECG's still show no signs of WPW!!

Medical Information






	Wolff (Wolfe) Parkinson White Syndrome (WPW)

What is Wolff (Wolfe)-Parkinson-White Syndrome?

Wolff (Wolfe)-Parkinson-White (WPW) is a very rare cause of sudden death. It results from an additional electrical connection between the atria (upper chambers of the heart) and the ventricles (lower chambers of the heart). This extra or accessory electrical pathway is present in approximately 1.5 per 1,000 people. It runs in families in less than 1% of cases. In the majority it is completely silent and only detected on a routine ECG. In a small proportion of patients the extra electrical pathway allows conduction of the electrical pathway generating an electrical circuit which produces a very rapid heart rate. Most patients tolerate this well but some experience very troublesome palpitations, light-headedness and blackouts. A very small minority of patients may die suddenly from ventricular fibrillation.

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Symptoms

Palpitations are the main symptoms. They can occur at any time and some patients learn to control them by holding their breath for prolonged periods. In many instances the palpitations remain until they are terminated by medical therapy in the accident and emergency department.

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Signs

When the patient is experiencing palpitations the heart rate is usually in excess of 150 beats per minute. When the patient has no symptoms there is nothing to find on examination.

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How is Wolff (Wolfe)-Parkinson-White diagnosed?

WPW is diagnosed by performing an ECG. The ECG usually shows two abnormalities when the patient is free of symptoms – a short PR interval and a delta wave. It is often an incidental finding during a routine ECG check as part of a medical insurance or detected by a cardiologist when a patient is referred with palpitations.

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Treatment

The ideal treatment in patients with symptoms is to destroy the extra electrical pathway, a procedure termed radio frequency catheter ablation. This is done by passing a wire into the heart, often via the large artery (femoral artery) in the leg. The abnormal pathway is located by electrical stimulation and destroyed by passing a high current through it. This takes approximately 2-3 hours and requires one night in hospital. For patients above 25 years without any symptoms there is no need for further tests. Younger patients (under 25 years) are most at risk of sudden death and require further tests to assess their risk of developing life threatening electrical disturbances. This is best done by performing an exercise test under the supervision of a cardiologist. The abrupt disappearance of the delta wave on the ECG as the heart rate increases is a good sign. Obviating the need for any further investigation, however, if this does not happen then further electrophysical testing is recommended before one can be reassured.

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