A large part of the mammalian genome is transcribed into noncoding RNAs. Long 
noncoding RNAs (lncRNAs) have emerged as critical epigenetic regulators of gene 
expression. Distinct molecular mechanisms allow lncRNAs either to activate or to 
repress gene expression, thereby participating in the regulation of cellular and 
tissue function. LncRNAs, therefore, have important roles in healthy and 
diseased hearts, and might be targets for therapeutic intervention. In this 
Review, we summarize the current knowledge of the roles of lncRNAs in cardiac 
development and ageing. After describing the definition and classification of 
lncRNAs, we present an overview of the mechanisms by which lncRNAs regulate gene 
expression. We discuss the multiple roles of lncRNAs in the heart, and focus on 
the regulation of embryonic stem cell differentiation, cardiac cell fate and 
development, and cardiac ageing. We emphasize the importance of chromatin 
remodelling in this regulation. Finally, we discuss the therapeutic and 
biomarker potential of lncRNAs.