5 Discussion
AIS during radiofrequency ablation procedure were often reported in
those atrial fibrillation patients with high risk of thromboembolism. On
the other hand, AIS during radiofrequency ablation of PVC patients was
rarely reported.4 To our knowledge, this is the first
case report on AIS during catheter ablation of PVC. AIS during
radiofrequency ablation may be associated with char formation at the
ablation tip. However, in our reported case, upon the patient’s
manifestation of the neurological symptoms, no charring was identified
on the tip of the withdrawn ablation catheter. Therefore, AIS might not
have been associated with charring in this case. The reasonable and
speculative source of the embolus was the tissue debris caused by the
ablation or catheter manipulation. Histopathological examination of a
retrieved embolus would be very helpful for identifying the precise
etiology and pathogenesis of this AIS. However, emergency cerebral
arteriography and interventions was refused. Nevertheless, considering
that the neurological symptoms were developed about 40 seconds after the
retrograde transaortic manipulation (at that time, reinforcement
ablation was not performed), it was reasonable to associate the AIS with
the retrograde transaortic manipulation. Therefore, this is the first
case report that AIS was associated with retrograde transaortic
manipulation due to the high contact force, but not due to the char
formation.
Retrograde transaortic catheter manipulation is a widely used and
first-line access route for mapping and ablation of ventricular
arrhythmias arising from the left ventricle.1Generally, retrograde transaortic approach was
safe.1,3 However, as presented in this case, the
retrograde transaortic manipulation could potentially result in AIS. The
excessive contact force during the aortic valve crossing by the ablation
catheter could potentially lead to dislodgement of unstable
atherosclerotic plaques, which was frequently found in those patients
with uncontrolled hypercholesteremia. The dislodged debris could lead to
thromboembolism, if the debris was occluded in an important artery, such
as the anomalous left vertebral artery indicated in this specific case.
Therefore, cautious the retrograde transaortic manipulation should be
performed by limiting the contact force as low as possible.
In clinical practice, AIS encountered during catheter ablation may often
have specific neurological symptoms. However, greater attention should
be given to those patients with nonspecific neurological symptoms, such
as dizziness, vertigo, and limb ataxia. Radiological examinations should
be performed for those patients with sudden onset and agnogenic
neurological symptoms during catheter ablation. For the patient in this
case, examinations confirmed the diagnosis of AIS (the left cerebellar
infarction), which may be a result of the occlusion of the anomalous
left vertebral artery by dislodged debris caused by the retrograde
transaortic catheter manipulation. Appropriate treatments were
administered for this patient to relieve her neurological symptoms after
the confirmed diagnosis. Fortunately, her symptoms were relieved after
the appropriate treatments and encountered no neurological sequelae
during the follow up. Therefore, the vigilance is crucial to evaluate
the risk of stroke and to give the appropriate treatments, especially in
patients with nonspecific neurological symptoms.
In conclusion, this report highlighted that AIS could be encountered in
some patients resulting from repeated retrograde transaortic
manipulation with excessive contact force.