Complex Substrate Leading to PVC-Mediated Systolic Dysfunction in addition to Sustained Monomorphic VT in Repaired...

Area of Science:

• Cardiology
• Electrophysiology
• Congenital Heart Disease

Background:

• Frequent premature ventricular complexes (PVCs) are linked to left ventricular (LV) dysfunction.
• Repaired tetralogy of Fallot (rTOF) patients often have ventricular arrhythmias due to surgical substrates.
• Limited data exists on PVCs and LV dysfunction in rTOF, particularly concerning arrhythmogenic isthmuses.

Purpose of the Study:

• To investigate the role of arrhythmogenic isthmuses in generating frequent PVCs and causing LV systolic dysfunction in a patient with rTOF.
• To demonstrate the impact of substrate ablation on PVC burden and LV function.

Main Methods:

• Case report of a patient with rTOF presenting with frequent PVCs and LV systolic dysfunction.
• Successful substrate ablation targeting anatomical VT isthmuses.
• Assessment of PVC burden and LV systolic function before and after ablation.

Main Results:

• The patient experienced frequent PVCs and LV systolic dysfunction, despite infrequent ventricular tachycardia requiring internal shocks.
• Substrate ablation of the identified VT isthmuses successfully abolished PVCs.
• Following ablation, LV systolic function normalized.

Conclusions:

• Arrhythmogenic isthmuses can be a source of frequent PVCs leading to LV dysfunction in rTOF.
• Substrate ablation of these isthmuses can resolve PVCs and improve LV function in rTOF.
• Rigorous clinical reasoning is crucial for tailoring treatments for LV dysfunction in complex congenital heart disease.