Noncompaction cardiomyopathy and heterotaxy syndrome

Area of Science:

• Cardiology
• Genetics
• Developmental Biology

Background:

• Left ventricular noncompaction cardiomyopathy (LVNC) is a rare congenital heart defect characterized by abnormal myocardial development.
• Heterotaxy is a complex congenital condition involving abnormal arrangement of visceral organs, often associated with congenital heart disease (CHD).
• The co-occurrence of LVNC and heterotaxy has been anecdotally reported, but its prevalence and implications remain largely unstudied.

Purpose of the Study:

• To investigate the prevalence of LVNC in a cohort of patients diagnosed with heterotaxy.
• To explore potential shared genetic mechanisms underlying the association between LVNC and heterotaxy.
• To highlight clinical implications for patients with co-existing LVNC and heterotaxy.

Main Methods:

• Retrospective review of the Indiana Network for Patient Care database.
• Identification of 172 patients with heterotaxy.
• Independent review of echocardiography and cardiac magnetic resonance imaging by two cardiologists to diagnose LVNC.

Main Results:

• A total of 13 out of 172 patients (7.5%) with heterotaxy met the imaging criteria for LVNC.
• The subgroup with both conditions frequently exhibited atrioventricular septal defects, dextrocardia, venous return abnormalities, and transposition of the great arteries.
• 61% of patients with LVNC and heterotaxy experienced arrhythmias, and 61% required medical management for chronic heart failure.

Conclusions:

• LVNC is significantly more prevalent in patients with heterotaxy compared to the general population, suggesting a potential shared genetic etiology.
• The co-occurrence of LVNC and heterotaxy is associated with a higher risk of arrhythmias and heart failure, necessitating careful clinical monitoring.
• Recognition of this association is crucial for anticipating increased peri-operative morbidity in patients undergoing cardiac surgery.