Hemodynamic tolerance of ventricular tachycardia under conscious sedation

Induction of sustained ventricular tachycardia (VT) can be essential when performing catheter ablation (CA). However, hemodynamic stability under ventricular tachycardia could be compromised, necessitating VT termination or additional hemodynamic support. Data on factors associated with hemodynamic compromise r during the VT are scarce.

Patients who underwent CA of VT at our hospital between January 2022 and October 2024 were prospectively enrolled. All patients underwent CA in conscious sedation (CS) with propofol and fentanyl or midazolam. Invasive blood pressure (BP) monitoring was performed. All induced sustained monomorphic VT episodes were analysed. Two groups according to hemodynamical tolerance were defined: hemodynamically tolerated vs not tolerated VT episodes. The VT episode was defined as hemodynamically unstable in case of BP drop and consequent need of VT termination. Localisation of endocardial low voltage areas was assessed based on electroanatomical mapping, according to the 17-segment model. Correlation of VT morphology, pre-und periprocedural parameters as well as endocardial low voltage areas with hemodynamical tolerance of VT was assessed.

Overall, 116 procedures in 95 patients (1.2 procedures per patient) were analysed. Mean age 64 (53.75-72) years, 95 (82%) male, 55 (47%) ischemic cardiomyopathy [ICM]). Fentanyl was used in 114 (98%), midazolam in 11 (9%) of procedures. A total of 150 sustained VT morphologies were induced (1.29 morphology pro procedure). 44 (29.3%) different VT episodes were hemodynamically unstable and had to be terminated. In univariate analysis, age (p=0.002), female sex (p=0.025), absence of prior myocardial infarction(MI) (p=0.0025), absence of LAD decease (p=0.022), renal insufficiency (p=0.001), absence of baseline medication with betablocker (p=0.034) and mexiletine (p=0.046), faster VT CL (p<0.001), longer intrinsic activation time on of VT ECG (p=0.0085), absence of total low voltage segments and especially absence of low voltage in segments 2,3,5,6,12,14 (basal anteroseptal, basal inferoseptal, basal inferolateral, basal anterolateral, mid anterolateral and apical septal, respectively) were associated with hemodynamic instability during the VT (Figure 2).

The most VT episodes were hemodynamically stable under conscious sedation and use of inotropic drugs. Certain pre- and periprocedural characteristics were associated with hemodynamic instability. Assessing those factors may help to plan the need of periprocedural hemodynamic support.