His-Purkinje system re-entry in patients with clustering ventricular tachycardia episodes

Aims: Multiple arrhythmia re-inductions were recently shown in His-Purkinjesystem (HPS) ventricular tachycardia (VT). We hypothesized thatHPS VT was a frequent mechanism of repetitive or incessant VTand assessed diagnostic criteria to select patients likely tohave HPS VT. Methods and results: Consecutive patients with clustering VT episodes (>3 sustainedmonomorphic VT within 2 weeks) were included in the analysis.HPS VT was considered plausible in patients with (i) impairedleft ventricular function associated with dilated cardiomyopathyor valvular heart disease; or (ii) ECG during VT similar tosinus rhythm QRS or to bundle-branch block QRS. HPS VT was plausiblein 12 of 48 patients and HPS VT was demonstrated in 6 of 12patients (50%, or 13% of the whole study group). Median VT cyclelength was 318 ms (250–550). Catheter ablation was successfulin all six patients. Conclusion: His-Purkinje system VT is found in a significant number of patientswith repetitive or incessant VT episodes, and in a large proportionof patients with predefined clinical or electrocardiographiccharacteristics. Since it is easily amenable to catheter ablation,our data support the screening of all patients with repetitiveVT in this regard and an invasive approach in a selected groupof patients.