Case report
A 36-year-old woman in whom a left
anterior cruciate ligament repairment was planned, reported a history of
3 months of palpitations and dyspnea in the pre-anesthetic examination,
where arrhythmic heart sounds were found, reason why she was referred
for cardiologist evaluation.
An initial electrocardiogram (ECG) showed sinus rhythm without any
abnormality and a normal echocardiogram was obtained. The 24 hours
Holter-ECG showed frequent PVCs with an arrhythmic burden of 35%
(Figure 1), so β-blocker therapy was prescribed. Ischemic substrate was
ruled-out with a dobutamine stress-echocardiogram as well as Chagas
disease and electrolyte disturbances. However, the CMR revealed
prominent trabeculae and deep recesses in the left ventricle (LV) apex,
as well as in the anterior, inferior and lateral wall of the LV. The
right ventricle (RV) was normal without any myocardial or function
disturbances (Figure 2). Therefore, the diagnosis of isolated LVNC
cardiomyopathy was proposed.
Despite the prescription of
highest-tolerated dose of β-blocker therapy, it was recorded a
persistent high PVCs burden (22%) in a 24 hours Holter-ECG; reason why
the patient was referred to the Electrophysiologist for ventricular
ablation. On the procedure day, the baseline ECG of the patient showed a
sinus rhythm with right ventricular outflow tract (RVOT) complexes in
ventricular bigeminy. The preliminary electrophysiology study found
normal sinus function test, normal atrioventricular conduction intervals
and absence of accessory pathways. Then a Pentarray Biosense® catheter
was used to obtain a RVOT-3D electroanatomic mapping with the CARTO-3
mapping system.
The activation map identified the
PVCs origin in the anterolateral segment of the RVOT (Figure 3) where
the topostimulation with pass mode and pattern-matching showed a
correlation of the ninety five percent compared with the extrasystole.
Then, radiofrequency ablation was performed. Afterwards, no tachycardia
was induced with the programmed auricular and ventricular heart
stimulation. No complications related to the procedure were reported and
the patient was discharged from the hospital on the next day, with her
previous antiarrhythmic medication. In the follow-up after 3 months of
the ventricular ablation, remains asymptomatic and free of PVCs.