Related Experiment Video
Updated: Jun 22, 2025

Cox-Maze IV Procedure Concomitant with Valvular Surgery In Situs Inversus Dextrocardia: A Single-Center Experience in China
Published on: February 11, 2022
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.
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.
Background:
Multilevel obstruction in left ventricular inflow and outflow predisposes to arrhythmias in Shone's complex (SC).
Objectives:
The purpose of this study was to study the prevalence and outcomes (heart failure [HF] hospitalization, cardiac transplant, death) of cardiac arrhythmias in adults with SC.
Methods:
Adults with SC (defined as ≥2 lesions out of supramitral ring, parachute mitral valve, subvalvular/valvular aortic stenosis (AS), and aortic coarctation) seen at Mayo Clinic between January 1999 and March 2020 were identified and evaluated for the presence of sustained atrial fibrillation, atrial flutter, and ventricular arrhythmias (VA). Kaplan-Meier survival analysis was used to calculate the occurrence of these arrhythmias.
Results:
Seventy-three patients with SC (mean age at first visit 33 ± 13 years) were identified. Most common anomalies were valvular AS (88%), coarctation (85%), parachute mitral valve (44%), subvalvular AS (44%), and supramitral ring (25%). Atrial arrhythmias were diagnosed in 24 patients (33%) at a mean age of 34.6 ± 12.7 years. Patients with atrial fibrillation and atrial flutter had higher number of surgeries, left atrial size, right ventricular systolic pressure, and HF hospitalizations. A rhythm control approach was used in majority of patients (75% on antiarrhythmic drugs and 50% underwent catheter ablation). Sustained VA occurred in 6 of 73 patients of whom 4 had an ejection fraction <40%. Death and cardiac transplantation occurred in 11 and 3 patients, respectively, during a median follow-up of 7.3 ± 6.0 years.
Conclusions:
In adults with SC, atrial arrhythmias occurred in one-third of patients, were associated with more HF hospitalizations, and frequently required rhythm control. Prevalence of sustained VA was 8% and implantable cardioverter-defibrillator implantation should be considered in those with reduced ejection fraction.
More Related Videos
12:45Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
Published on: December 11, 2017
16:40A New Single Chamber Implantable Defibrillator with Atrial Sensing: A Practical Demonstration of Sensing and Ease of Implantation
Published on: February 28, 2012
Related Concept Videos
Mechanism of Cardiac Arrhythmias
Disturbances in Heart Rhythm
Arrhythmias are categorized by their speed, rhythm, and origin. A slow...
Electrophysiology of Normal Cardiac Rhythm
ECG Interpretation of Arrhythmias I: Sinus Arrhythmias
Types of Arrhythmias
Sinus Node Arrhythmias
Sinus Bradycardia: Originating from the sinoatrial (SA) node, sinus bradycardia involves slower impulses, resulting in a heart rate of less than 60 beats per minute (bpm). Causes include sleep, vagal stimulation, beta-blockers, hypothyroidism,...
Cardiovascular System Abnormal Findings II: Auscultation
Abnormal Heart Sounds
Gallops:
Antiarrhythmic Drugs: Class II Agents as β-Adrenergic Blockers