Pediatric cardiomyopathies: A review of literature on clinical status and meta-analysis of diagnosis and clinical management methods

Abstract

Cardiomyopathies define a heterogeneous group of heart muscle disorders. They are an important cause of heart failure and a leading indication for heart transplantation in pediatric patients. Research on cardiomyopathy has however focused on the adult populations with fewer dedicated clinical trials investigating pediatric cardiomyopathy. Diagnosis and clinical management of pediatric cardiomyopathy are also challenging because of the lack of specific methods for diagnosis and treatment. Assessment of ventricular structure using absolute values in adults are not useful in children because of their constantly changing body surface area. Therapies developed for adults applied to pediatric patients also have had varied clinical outcomes. This paper therefore reviews existing research evidence on pediatric cardiomyopathy, with the objective of broadening its clinical understanding and management.

Pediatric Cardiomyopathies: Establishing Genotype-Phenotype Relationship as a Determinant in Prognosis and Therapy: A Review of the Literature

“…1,[13][14][15][16] The main phenotypes (Table 1) in pediatrics are dilated cardiomyopathy (DCM) and HCM, followed by less frequent phenotypes such as non-compaction cardiomyopathy (NCCM), restrictive cardiomyopathy (RCM), and arrhythmogenic cardiomyopathy (ACM). [1][2][3]17 DCM occurs in approximately 50% of patients and HCM is responsible for just over a third of cases in this age group. The annual incidence of these phenotypes is estimated to be between 0.8 and 1 per 100,000 children.…”

“…They can manifest from the neonatal period until the end of adolescence, which makes diagnosis challenging. 1,17,29 Given that the etiology is highly varied, acquired causes must initially be ruled out. Through personal history, it is possible to identify recent infections that may indicate a condition of myocarditis or even signs and symptoms of autoimmune, inflammatory, and metabolic diseases, directing specific approach and treatments.…”

Symptomatic presentation influences outcomes in pediatric restrictive cardiomyopathy

“…Restrictive cardiomyopathy (RCM) is the least common form of cardiomyopathy, accounting for 2%-5% of pediatric cardiomyopathies (1)(2)(3). RCM is characterized by diastolic dysfunction, with normal or decreased volume of both ventricles associated with biatrial enlargement, normal left ventricular wall thickness and atrioventicular valves, and impaired ventricular filling with restrictive physiology (3,4).…”

“…This is contributed to at least in part by challenges in establishing diagnosis due to absence of symptoms in early disease and difficulties in using currently available mechanical circulatory support (MCS) options to support RCM patients in endstage heart failure to transplant (13). Of those who do present with symptoms, presentation varies from palpitations, chest pain, syncope, congestive heart failure (CHF) symptoms, and even sudden cardiac death, which has been attributed to subendocardial ischemia secondary to high diastolic pressures (1,3,14). Unlike cardiomyopathies characterized by systolic ventricular dysfunction, where evidence-based guidelines exist on timing of heart transplant listing based on clinical status and heart failure severity, risk factors for death in RCM are less well-established and listing practices are largely center dependent (2,(15)(16)(17).…”