Isolated noncompaction of the myocardium

Mediating ERK 1/2 signaling rescues congenital heart defects in a mouse model of Noonan syndrome

Noonan syndrome (NS) is an autosomal dominant disorder characterized by a wide spectrum of defects, which most frequently include proportionate short stature, craniofacial anomalies, and congenital heart disease (CHD). NS is the most common nonchromosomal cause of CHD, and 80%-90% of NS patients have cardiac involvement. Mutations within the protein tyrosine phosphatase Src homology region 2, phosphatase 2 (SHP2) are responsible for approximately 50% of the cases of NS with cardiac involvement. To understand the developmental stage- and cell type-specific consequences of the NS SHP2 gain-of-function mutation, Q79R, we generated transgenic mice in which the mutated protein was expressed during gestation or following birth in cardiomyocytes. Q79R SHP2 embryonic hearts showed altered cardiomyocyte cell cycling, ventricular noncompaction, and ventricular septal defects, while, in the postnatal cardiomyocyte, Q79R SHP2 expression was completely benign. Fetal expression of Q79R led to the specific activation of the ERK1/2 pathway, and breeding of the Q79R transgenics into ERK1/2-null backgrounds confirmed the pathway's necessity and sufficiency in mediating mutant SHP2's effects. Our data establish the developmental stage-specific effects of Q79R cardiac expression in NS; show that ablation of subsequent ERK1/2 activation prevents the development of cardiac abnormalities; and suggest that ERK1/2 modulation could have important implications for developing therapeutic strategies in CHD.

Splenic rupture and haemoperitoneum in a patient with non-compaction of the left ventricular myocardium

The anaesthetic and critical care management of blunt abdominal trauma in a patient previously diagnosed with non-compaction of the left ventricular myocardium (a rare autosomal dominant inherited disease) is reported. The management was influenced by the presence of an implanted automated internal defibrillator and treatment with anticoagulants because of the high frequency of severe arrhythmias and systemic embolism. The pathophysiology of ventricular non-compaction is reviewed briefly.

An unusual cause of heart failure identified by echocardiography in an octogenarian

Non-compaction of the ventricular myocardium is a rare congenital cardiomyopathy that carries an unfavorable prognosis. It is associated with a high incidence of progressive heart failure, thromboembolism and malignant arrhythmias. Echocardiography currently remains the imaging modality most commonly used for diagnosis. We describe an unusual case of isolated non-compaction of the left ventricle in an octogenarian male to highlight the need for echocardiography in all patients with suspected heart failure, in order to determine aetiology, prognosis and assess treatment.