Left Ventricular Noncompaction Syndrome Masquerading or Misdiagnosed as Congenital Long QT Syndrome: Remember QT Prolongation Does Not Equal Long QT Syndrome

Abstract

Distinguishing congenital long QT syndrome from QT prolongation caused by drugs or a different underlying disease process is essential for selecting the proper treatment. Herein, we present a case of a patient referred for left cardiac sympathetic denervation as a last resort treatment option for her 19-year standing diagnosis of long QT syndrome with malignant ventricular fibrillation. However, based on her atypical clinical course and additional imaging studies, a diagnosis of left ventricular noncompaction, rather than long QT syndrome, was made. She left the clinic with a drastically different treatment plan and an improved quality of life. Because many cardiac and noncardiac diseases can demonstrate QT prolongation on electrocardiogram, all possible diagnoses should be considered before diagnosing a patient with congenital long QT syndrome especially with regard to the profound treatment implications and genetic follow-up in family members.

Evaluation of Prolonged QT Interval: Structural Heart Disease Mimicking Long QT Syndrome

“…Coleman et al. presented a case of a patient with nearly a two‐decade‐long diagnosis of LQTS who was referred to the Mayo Clinic for videoscopic left cardiac sympathetic denervation surgery and was later discharged with a diagnosis of LVNC and an LVNC‐directed treatment plan …”

“…44 Coleman et al presented a case of a patient with nearly a two-decade-long diagnosis of LQTS who was referred to the Mayo Clinic for videoscopic left cardiac sympathetic denervation surgery and was later discharged with a diagnosis of LVNC and an LVNC-directed treatment plan. 45 ASD was diagnosed in two gene-negative patients displaying prolonged QT interval on their surface ECG. In one, this was associated with bileaflet MVP and in the other with partial anomalous pulmonary venous connection resulting in a significant left to right shunt.…”