Dual myosin binding protein C3 and potassium voltage-gated channel subfamily H member 2 co-inherited pathogenic variants in a patient with hypertrophic cardiomyopathy and long QT 2 syndrome: A case report

Figures

• 

  Figure 1. Genetic family pedigree.

• 

  Figure 2. A: Transthoracic echocardiography (TTE) parasternal long-axis view demonstrating interventricular septal wall thickness of 2.62 cm and posterior wall thickness of 1.85 cm. B: TTE 3 chamber view with continuous wave Doppler at the left ventricular outflow tract (LVOT) during Valsalva maneuver revealing LVOT gradient of 89 mm Hg. C: Cardiac magnetic resonance imaging (MRI) short-axis view revealing maximal basal anteroseptal wall thickness of 2.8 cm. D: Cardiac MRI 4-chamber long-axis view demonstrating midmyocardial late gadolinium enhancement in the interventricular septum (orange arrow). E: Post–surgical myectomy specimen.

• 

  Figure 3. A: Initial electrocardiogram after second cardiac arrest demonstrating sinus rhythm 66/min, left ventricular hypertrophy with repolarization changes, and prolonged QT with corrected QT interval of 533 ms. B: Subcutaneous implantable cardioverter-defibrillator (ICD) interrogation demonstrating polymorphic ventricular tachycardia / ventricular fibrillation successfully terminated by ICD shock.