Fabrizio Drago, Maurizio Bevilacqua, Andrea Mazza*, Massimo Stefano Silvetti, Paolo Versacci, Silvia Anaclerio, Pietro Ragonese.
Bambino Gesu Hospital, Rome, *S. Camillo Hospital, Rome, Italy
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Permanent junctional reciprocating tachycardia
(PJRT) is an uncommon type of supraventricular reentry tachycardia, generally incessant,
often resistant to pharmacologic therapy, which may result in impaired left ventricular
performance due to the tachycardia-related cardiomyopathy1-3. Aim of the study was to
evaluate in infants and children affected by PJRT: 1) the efficacy of the antiarrhythmic
drug therapy, 2) the possibility of delaying RFTA by the use of drug therapy and 3) the
results of this combined medical and non medical treatment. The study includes 14 children
affected by PJRT (6 M, 8 F), who were referred to our Hospital between 1987 and 1997.
Initial evaluation included: electrocardiogram at rest, chest roentgenogram, 24 hour dynamic
electrocardiogram and mono- and 2-dimensional echocardiogram. The tachycardia was
defined incessant if present during Holter monitoring in more than 90% of the recording.
Therapy was judged effective if PJRT was suppressed both during the 12-lead ECG and
during the Holter monitoring. Serial echocardiographic evaluations of the left ventricular
shortening fraction were performed to assess the reversibility of tachycardia induced left
ventricular dysfunction during successful treatment.
The patients were considered for RFTA in case of therapy failure and/or after reaching at
least 10 years of age. The electrophysiological study was performed using five standard
electrode catheters, in pharmacological wash-out and in general anesthesia. Two tetrapolar
or esapolar catheters were placed in the high lateral right atrium, His bundle; a decapolar
catheter was inserted in the coronary sinus. A 7 French deflectable thermistor tipped
catheter (Blazer, EP Technologies) with a 4 mm tip, was inserted via the right femoral vein
and used for mapping and ablation. Mapping of the accessory pathway was performed
recording the shortest ventriculo-atrial interval during tachycardia. The radiofrequency
generator (EPT-1000 cardiac ablation controller) was set to achieve a temperature no
higher than 70°C. RFTA was considered effective not only if the tachycardia did not resume
spontaneously but also if it was not inducible by programmed stimulation 1 hour after the
ablative procedure, both in basal condition and during isoprenaline infusion.
Student’s t test and Fisher exact test was used to analyze our data. At the first evaluation
the age of the patients ranged from 1 day to 13 years (mean 60.7±60.6 months, median
48), the mean heart rate of tachycardia was 176±28 bpm. Five patients exhibited the first
episode of tachycardia during the first year of life (mean age 2.4±2.6 months, median 1).
In these patients the mean tachycardia rate, at the time of presentation, was 194±24 bpm,
while in the other patients (mean age 93±52 months, median 106) was 167±27 (p=0.01).
PJRT was incessant in 11 patients. Eight patients had, at the time of the first evaluation,
reduced left ventricular function with a mean shortening fraction, at the echocardiographic
examination of 14±3.5%, not statistically related to the age, to the tachycardia rate and
to the fact that the tachycardia was incessant or not. Antiarrhythmic therapy was given to
12 patients. One patient, 13 years old, was initially not treated because the tachycardia
was not incessant and with low rate. When he was 18 years old, as PJRT became
incessant and with higher heart rate, he underwent RFTA. The remaining patient, 10 years
old, was immediately submitted to RFTA because of a very poor left ventricular performance.
Thirty-one drug regimens were administered to 12 patients (2±1.2 drugs for each patient).
Mean follow-up duration of medical treatment was 62±57.4 months. Combined antiarrhythmic
treatment was found to be effective in 7 patients (5 with flecainide and propranolol, 1 with
propafenone and sotalol, 1 with amiodarone and propranolol), while a drug used alone in 5
(4 with amiodarone, 1 with propafenone). Normalization of the left ventricular shortening
fraction was obtained in 7/7 patients after 3 to 6 months of medical treatment. Eight patients
were submitted to RFTA. The mean age at the time of RFTA was 151±16 months. The shortest
VA interval (mean value 251±59 msec) was recorded in all cases at the coronary sinus ostium.
The radiofrequency energy delivered at that site (mean value of the energy 26±3 watts;
mean value of temperature 64±5°C) interrupted the arrhythmia in all cases with an average
number of pulses of 2.5±1.4. The mean value of local VA-RP’ was -40±9 msec. This value was
not significantly different between patients with and without arrhythmia recurrences after
RFTA (38±1.6 vs 41±11.9 msec). Ten procedures were performed in 8 patients because 2
patients had recurrences 1 month and 8 months after the apparently successful procedure.
After a mean follow-up of 23±17 months all patients are arrhythmia free.
We did not observe complications related to RFTA in any case. However, RFTA, when
performed in very small children, is not free of risks. Sudden death or minor complications
suggest to delay the procedure until the patient has reached the body weight of 15 kg4.
In our series we obtained good results using antiarrhythmic drugs in combination in 7 out of
12 patients (58%). The suppression of the arrhythmia was obtained in 12/12 patients treated
with medical therapy with a complete resolution of secondary left ventricular dysfunction in
7/7 patients. Radiofrequency ablation was successful in the right posteroseptal region in all
treated patients without early complications.
In conclusion, the combination of a class I drug or amiodarone plus a beta-blocker agent
seems to be effective in children with PJRT. This treatment allows to delay the highly effective
ablative treatment, in order to reduce the risk of complications when RFTA is performed in
young children.
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