Supraventricular arrhythmias in noncompaction of left ventricle: is this a frequent complication?

Background: Isolated left ventricular noncompaction is the result of incomplete myocardial morphogenesis, leading to persistence of the embryonic myocardium. The condition is recognised by an excessively prominent trabecular meshwork and deep intertrabecular recesses of the left ventricle. Whether these intertrabecular recesses are a favorable substrate for supraventricular arrhythmias is unclear, even if the incidence of chronic heart failure seems to be high.
Results: We evaluated a continuous series of 238 patients affected by noncompaction. In 4 cases the patients reported palpitations and in 4 an episode of syncope. Periodic holter monitoring was performed every 6 months for 4 years. Only 9 patients had documented atrial fibrillation. In no cases we observed supraventricular tachycardia.
Conclusions: Noncompaction alone does not seem to be a risk factor for supraventricular arrhythmias.