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.