Short coupled Ventricular Fibrillation in a patient with TRPM4 mutation

Area of Science:

• Cardiology
• Genetics
• Electrophysiology

Background:

• Inherited channelopathies can cause syncope in structurally normal hearts, often presenting with subtle or absent ECG abnormalities.
• Short coupled Ventricular Fibrillation (VF), characterized by normal QTc and frequent Ventricular Premature Complexes (VPCs), is a critical cause of syncope.
• TRPM4 gene mutations, affecting calcium-activated channels regulating Sinoatrial node depolarization, can lead to bradyarrhythmias or atrial arrhythmias.

Observation:

• A case of intractable short coupled VF with coexistent tachy-brady syndrome is presented.
• The condition was attributed to a TRPM4 gene mutation.
• Despite antiarrhythmic therapy and an implantable cardioverter-defibrillator (ICD), VF persisted.

Findings:

• Quinine administration led to significant symptom alleviation in a patient with TRPM4-mutation-associated VF and tachy-brady syndrome, particularly when quinidine was unavailable.
• This suggests a potential therapeutic role for quinine in managing refractory ventricular arrhythmias in specific genetic contexts.
• The case highlights the diagnostic and therapeutic complexities associated with inherited channelopathies.

Implications:

• This case underscores the importance of genetic testing in unexplained syncope and arrhythmias.
• It highlights the potential for alternative antiarrhythmic strategies, such as quinine, in managing challenging cases.
• Personalized treatment approaches are crucial for optimizing outcomes in patients with inherited channelopathies.