Kearns-Sayre syndrome associated with trifascicular block and QT prolongation

Area of Science:

• Cardiology
• Neurology
• Genetics

Background:

• Kearns-Sayre syndrome (KSS) is a rare mitochondrial disorder.
• Conduction defects are common in KSS, potentially leading to syncope or sudden cardiac death.
• The coexistence of conduction abnormalities and prolonged QT interval in KSS is exceptionally rare.

Observation:

• A patient with KSS and diabetes mellitus presented with a syncopal attack.
• The patient exhibited trifascicular block and significant QT prolongation (QTc: 574 ms).
• The syncope was attributed to torsades de pointes.

Findings:

• Torsades de pointes was identified as the cause of syncope in this KSS patient.
• The patient had coexisting trifascicular block and prolonged QT interval.
• Successful treatment was achieved with permanent pacing.

Implications:

• Torsades de pointes is a critical, albeit rare, mechanism for syncope and sudden cardiac death in KSS.
• This case underscores the importance of monitoring for and managing cardiac conduction abnormalities and QT prolongation in KSS patients.
• Early detection and intervention, such as permanent pacing, can be life-saving.