1Universitäts-Herzzentrum Freiburg / Bad Krozingen Klinik für Kardiologie und Angiologie Bad Krozingen, Deutschland; 2RHÖN-KLINIKUM AG Campus Bad Neustadt Klinik für Kardiologie II / Interventionelle Elektrophysiologie Bad Neustadt a. d. Saale, Deutschland; 3RHÖN-KLINIKUM AG Campus Bad Neustadt Klinik für Kardiologie/Rhythmologie Bad Neustadt a. d. Saale, Deutschland
Background: Patients undergoing ablation of ventricular tachycardia (VT) often present with heart failure due to structural heart disease and other comorbidities. The induction of VT during VT catheter ablation challenges the compromised cardiovascular compensatory mechanisms in this patient population to sustain hemodynamic stability and organ perfusion.
Objective: The present study screens for cerebral oxygen desaturation phases in patients undergoing VT ablation and identifies clinical features of patients at risk of cerebral hypoperfusion.
Methods: Consecutive patients (06/2018 – 05/2021) presenting with sustained VT for ablation were prospectively included in this single center observational study. Near-infrared spectroscopy (NIRS) was administered during VT ablation procedure and cerebral oxygen desaturation phases (ODPs) were identified as local minima in tissue oxygenation index. Patients with ODPs were compared to patients without in terms of clinical and procedural features.
Results: A total of 47 patients (age: 61±14 years, male: 72%, ischemic heart disease (IHD): 32[JM1] %) underwent VT ablation with simultaneous cerebral NIRS monitoring. Of all patients 62% encountered cerebral ODPs with an average drop in tissue oxygenation index of 10%. Patients with occurrence of ODPs had higher rates of IHD (45% vs. 11%, p = 0.024), higher number of previous VT episodes before ablation (n = 16 vs. 4, p = 0.018) and the number of VTs inducible during the ablation procedure (n = 2.4 vs. 1.2, p = 0.004). Patients with ODPs did not exhibit a lower ejection fraction as compared to controls (34% vs. 38%, p = 0.567), but ODPs were associated with admission to intensive care units (78% vs. 33%, p = 0.005) and spontaneous VT recurrence (24% vs. 0%, p = 0.034). IHD (OR: 32.837 [95%CI: 2.686 - 402.473], p = 0.006), intensive care unit (ICU) admission (OR: 14.112 [95%CI: 1.762 - 113.025], p = 0.013) and the number of VTs inducible during VT ablation (OR: 2.705 [95%CI: 1.217 - 6.010], p = 0.015) were independently associated with the occurrence of ODPs.
Conclusions: ODPs during VT catheter ablation are a common event affecting two thirds of patients. A high number of previously documented VT episodes before ablation, IHD and a large variety of VTs inducible during the ablation procedure indicate towards an increased risk to encounter ODPs. A standard application of neuromonitoring during VT ablation should be considered to prevent cerebral hypoperfusion phases.