A 26-year-old woman with a history of tetralogy of Fallot underwent definitive corrective surgery consisting of closure of her communication and expansion of the RVOTF and the pulmonary valve annulus with pericardial patch in childhood.
Since the age of 8 years, she had recurrent episodes of SVT, despite pharmacological treatment with amiodarone, requiring multiple hospitalizations to be treated with intravenous antiarrhythmic drugs or electrical cardioversion.
Echocardiographic follow-up showed moderate impairment of right ventricular systolic function, free pulmonary insufficiency and progressive dilation of the RVOTF, which became a true aneurysm. At 18 years of age, the patient underwent homograft aortic aneurysm resection.
Since this last intervention, she remained asymptomatic, free of arrhythmias, in functional capacity I. She continued on treatment with amiodarone, which stopped at age 23 due to pregnancy.
At the age of 26 years, the patient presented with a rapid episodes of seizures.
Located in an emergency service, where ventricular tachycardia with a frequency of 150 beats per minute was documented, with image of complete blockage of
left branch and left lower axis, without hemodynamic compromise.
She was hospitalized and treated with intravenous amiodarone, despite tachycardia, which was diagnosed 24 h after admission, electrical cardioversion was performed.
His electrocardiogram in sinus rhythm showed atrioventricular conduction with PR of 200 ms and wide QRS complexes with image of complete right bundle branch block and 240 ms duration.
The patient was hospitalized and had a recurrence of SVT. A second morphology was observed, so it was decided to try treatment with radiofrequency fulguration.
Electrophysiological study was performed under sedation with midazolam and fentanyl.
Three quadripolar catheters (Daig®, St. Jude Medical Inc) were advanced through the right femoral vein. The right ventricle was located in the upper region of the right atrium, in order to register the potential endo-stimulation.
Stimulation from the apex of the right ventricle with a basal cycle of 550 ms and introduction of two extrasystoles easily occurs in two tachycardia morphologies.
Median mapping during RVOTS with EPT fulguration catheter standard curve and 4 mm tip (Boston Scientific Corporation) 12 leads to morphologic stimulation of both tachycardias.
Radiofrequency was also applied in the infundibulum region, identifying areas of fragmented electrograms and potential mediodiastolic during tachycardia.
A total of 46 radiofrequency pulses were completed.
Post-frequency ventricular pacing was repeated, introducing up to three extrasystoles, without achieving reinduction of SVT even under the effect of intravenous isoproterenol infusion.
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The patient was discharged 48 hours later with amiodarone 100 mg/day.
After 6 months, the antiarrhythmic drug was discontinued due to a new pregnancy.
After one year of follow-up, he remained asymptomatic and his 24-h electrocardiogram monitoring showed only occasional isolated ventricular extrasystole of morphology different from that of treated ventricular tachycardias.
