PREOPERATIVE DIAGNOSIS:
1. Wolff-Parkinson-White syndrome.
POSTOPERATIVE DIAGNOSES:
1. Wolff-Parkinson-White syndrome.
2. Successful radiofrequency ablation of three separate accessory
pathways.
COMPLICATIONS:
OPERATOR:
None.
George F. Van Hare, M.D.
PRIMARY ANESTHESIA:
General.
CLINICAL DATA: This 15-1/2-year-old young man has congenital rubella
syndrome with mental retardation, mild cerebral palsy, and sensory
neural hearing loss. He wears hearing aids, has undergone cataract
surgery, and as an infant had ligation of a patent ductus arteriosus.
He has been known to have Wolff-Parkinson-White syndrome since birth.
Recently, he has been experiencing more frequent episodes of rapid
heart rate and so is referred for electrophysiology study and possible
catheter ablation.
His electrocardiogram showed clear evidence of Wolff-Parkinson-White
syndrome and the pattern of preexcitation suggested a right
posteroseptal accessory pathway location.
PROCEDURE IN DETAIL: The patient was transported to the
electrophysiology laboratory in a fasting state. General anesthesia
was induced. The right neck and both groins were prepped and draped in
a sterile fashion. After the instillation of local anesthetic, four
sheaths were placed in the right internal jugular vein and right
femoral vein and through these sheaths, four intracardiac
electrocatheters were advanced into the heart. These included a
decapolar catheter advanced from the jugular vein into the coronary
sinus. In the baseline state, there was clear evidence of
bidirectional accessory pathway conduction, in the earliest local
activation during sinus rhythm was in the proximal coronary sinus.
Sustained supraventricular tachycardia was not inducible, but antegrade
conduction down the pathway was potentially malignant as it went oneto-one all the way down to a cycle length of 220 msec, faster rates not
being tested. Echo beats could be induced at the accessory pathway
effective refractory. The earlier ventriculoatrial activation during
echo beats as well as during ventricular pacing was at CS78, which was
adjacent to the coronary sinus os on fluoroscopy. The hybrid atrial
catheter was exchanged for a 7-French radiofrequency ablation catheter
which was advanced into the heart for careful further mapping. This
showed that the earliest ventricular activation initially was found at
locations in the posterior septum. A fairly large area of early
ventricular activation was detected, however. Initially, excellent
catheter contact was achieved at 7 o'clock on the clock face in LAO
view on the tricuspid annulus, and this location was several
centimeters away from the os of the coronary sinus. At this location,
a local ventricular activation 35 msec earlier than surface QRS was
recorded with atrial and ventricular fusion. Radiofrequency
application at this location caused sudden change in local electrogram
morphology with good separation, but without complete loss of
preexcitation. The pattern of preexcitation was slightly different,
however, with slightly less preexcitation. Further mapping was then
carried out and this now revealed that the earliest local ventricular
activation was adjacent to the coronary sinus os at CS78. Additional
radiofrequency application at this location caused complete loss of
preexcitation. After several lesions were completed at this location,
retesting was carried out and this showed that ventriculoatrial
conduction was still present, was not decremental, and seemed earliest
at CS78. Further mapping of retrograde conduction during ventricular
pacing showed that, in fact, the earliest retrograde atrial activation
was on the septum, in a low intermediate septal location about a
centimeter superior to the coronary sinus os. Radiofrequency
application at this location, performed during sinus rhythm so that AV
conduction could be monitored, caused complete loss of ventriculoatrial
conduction after one lesion. After an additional lesion was placed at
this location, the patient was monitored and retested after a 30-minute
waiting period. At the end of this period, there was no evidence for
preexcitation, ventriculoatrial conduction was absent, and there were
no other substrates for arrhythmias. The patient tolerated the
procedure well and no complications were noted.
The patient will be returned to the recovery room and will stay in the
Day Hospital for about 4 hours prior to discharge. He should follow up
with his referring pediatric cardiologist, Dr. Y.T. Lan, at Santa Clara
Valley Medical Center in about a month's time. The likelihood of
recurrence is low and is probably on the order of 5%.