2.4. The definition of non-inducibility and the impact of the
clinical VT
At the end of the RF ablation, in those that no sustained VT could be
induced, they were designated with VT non-inducibility. The patients in
whom only non-sustained VT (termination within 30 seconds) or
ventricular fibrillation (VF) was induced, were also classified as
having VT non-inducibility. In contrast, if sustained VT was induced,
regardless of whether it was clinical or non-clinical, the patient was
judged as having residual VT inducibility. Among the patients in whom
VTs were sustained or induced at baseline, the patients that did not
undergo a VT induction test or only received an inadequate VT induction
test at the end of the procedure due to the patient’s condition, were
also classified as having residual VT inducibility. The induced VTs were
defined as being clinical if they matched the arrhythmia captured
clinically on the 12 lead ECG or, in cases where no ECG was available,
they matched the tachycardia cycle length of the implantable
cardioverter defibrillator log (difference <30ms).
In order to analyze the impact of the clinical VT inducibility at the
end of the procedure, the patients were classified into 2 groups
according to the presence or absence of inducibility of the clinical VT
at the end of the procedure: Group A –
all clinical VT isthmuses were
identified and ablated, and those VTs could no longer be induced
thereafter (Figure 2), and Group B – none or some of the clinical VT
isthmuses could not be identified or were identified and ablated but
remained inducible.