Atrial and Ventricular Arrhythmia in Adults With Shone Complex: A Single-Center Cohort Study

Jaideep S Bhalla1, William Miranda1, C Charles Jain1

  • 1Department of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota, USA.

JACC. Advances
|June 28, 2024
PubMed

Insights

In adults with Shone's complex (SC), atrial arrhythmias affect one-third of patients, leading to more heart failure hospitalizations. Ventricular arrhythmias (VA) occur in 8%, warranting consideration for defibrillator implantation in those with reduced ejection fraction.

Area of Science:

  • Cardiology
  • Congenital Heart Disease
  • Electrophysiology

Background:

  • Shone's complex (SC) is characterized by multilevel left ventricular inflow and outflow obstructions.
  • These obstructions predispose individuals to cardiac arrhythmias.

Purpose of the Study:

  • To determine the prevalence of cardiac arrhythmias in adults with Shone's complex.
  • To evaluate the outcomes, including heart failure hospitalizations, cardiac transplantation, and death, associated with these arrhythmias.

Main Methods:

  • Adults with Shone's complex (defined by ≥2 lesions including supramitral ring, parachute mitral valve, subvalvular/valvular aortic stenosis, and aortic coarctation) were identified.
  • Patients were assessed for sustained atrial fibrillation, atrial flutter, and ventricular arrhythmias (VA).
  • Kaplan-Meier survival analysis was used to determine arrhythmia occurrence.

Main Results:

  • Seventy-three adult patients with SC were identified, with valvular aortic stenosis and coarctation being the most common anomalies.
  • Atrial arrhythmias were diagnosed in 33% of patients, associated with increased heart failure hospitalizations and requiring rhythm control strategies.
  • Sustained VA occurred in 8% of patients, with 4 out of 6 having reduced ejection fraction (<40%).

Conclusions:

  • Atrial arrhythmias are common in adults with Shone's complex, contributing to significant morbidity.
  • Ventricular arrhythmias pose a risk, particularly in patients with reduced ejection fraction, suggesting a role for implantable cardioverter-defibrillators.
Abstract

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