Management and outcome of different types of ventricular tachycardia related to hypokalemia

Abstract Background Hypokalemia is a potentially reversible cause of ventricular tachyarrhythmias (VTs) such as polymorphic ventricular tachycardia/ventricular fibrillation (PMVT/VF) and sustained monomorphic ventricular tachycardia (SMVT). Despite its established role in arrhythmogenesis, the clinical implications of hypokalemia in patients with distinct VT subtypes remain poorly understood. Purpose This study aims to characterize the clinical characteristics, management, and outcome of patients with hypokalemia-associated PMVT/VF and SMVT. Additionally, we investigate whether prognosis differs between these VT subtypes after correction of hypokalemia and evaluate the need for supplementary VT-targeted therapies (VTTT), such as catheter ablation or antiarrhythmic drug treatment, to improve patient outcome. Methods Sixty-five consecutive patients who presented with sustained hypokalemia-associated VTs between 2014 and 2024 were analyzed. Patients were categorized based on VT subtype and followed for VT recurrence, all-cause mortality, and 24-month VT-free survival. Results Of the total cohort (69±12 years, 20% female, mean LVEF 32%, 54% ≥NYHA III, 8% LVAD), 68% presented with SMVT. SMVT patients were younger (65±11 vs. 77±10 years, P<0.001) and had more advanced left ventricular dilation (LVEDD 64±12 vs. 57±12mm, P=0.03) compared to PMVT/VF patients. Median follow-up time was 18 (IQR 6-31) months and overall 24-month VT-free survival 28%. The VT recurrence rate at 24 months was significantly higher (50 vs. 10%, P=0.002) and 24-month VT-free survival rate significantly lower (16 vs. 52%, P=0.005) in patients with SMVT compared to those with PMVT/VF (Figure 1A+B). Notably, SMVT patients who underwent VTTT had a significantly improved 24-month VT-free survival compared to those who received correction of hypokalemia only (31% vs. 7%, P=0.02) (Figure 1C). Conclusion Hypokalemia-related VTs are associated with advanced heart failure and linked to poor outcome, especially in patients with SMVT. While potassium correction is essential in hypokalemic patients with sustained VT, patients with SMVT often require additional substrate-targeted antiarrhythmic therapy to improve outcome.