Definition and Classification of Heart Failure
in Children
Definition
Heart failure was classically viewed as synonymous with
left ventricular pump dysfunction, usually progressive, culminating
in a common end-stage cardiac phenotype of dilation,
thinned walls, and poor contractility.14 In recent years,
this thinking has been refined and expanded to include further
understanding not only of cardiac mechanics, but also of the
complex pathways that modulate normal and abnormal cardiac
performance.15–17 And if the rapidly expanding systems
biology of heart failure is not confusing enough, pediatric heart
failure encompasses clinical presentations as disparate as an
infant presenting with acute decompensated heart failure secondary
to idiopathic dilated cardiomyopathy and a teenager
presenting with dyspnea in the setting of palliated complex heart
disease. These complexities make a “grand unifying theory” of
heart failure difficult to achieve in children.
Several groups have tackled the definition problem in the
context of adult and pediatric practice guidelines.11,18 There is
general agreement that heart failure is a progressive clinical
syndrome with numerous etiologies and characteristic signs
and symptoms, although the causes and clinical presentations
may differ considerably among children of different age