Summary: A 53-year-old female presents with new onset systolic heart failure as diagnosed by echocardiography. A cardiac magnetic resonance imaging (MRI) is ordered to evaluate for a cardiomyopathy. (Images are best viewed as cines using the DICOM viewer). If you are unable to use the DICOM viewer, the sequences below are 4-chamber steady-state free precession (SSFP), 2-chamber long-axis SSFP, 2-chamber short axis SSFP at the end diastole and the end systole, and 2-chamber short-axis late gadolinium enhanced images 15 min after the administration of intravenous gadolinium.
Diagnosis
Left ventricular noncompaction cardiomyopathy
Findings
The left ventricle is severely dilated with very prominent trabeculation along the
anterolateral, lateral, and inferolateral wall. The trabeculated portion of the
wall measures >2.3 times the thickness of the compacted myocardial wall. There
is global hypokinesis involving the entire left ventricle with an ejection fraction
of approximately 16%. The atria are severely enlarged. Late gadolinium enhanced
images demonstrate dense enhancement along the insertion sites of the right
ventricle with mild-patchy enhancement along the basal portion of the anterior
wall (DICOM only). DICOM images also demonstrate moderate mitral regurgitation.
Discussion
Left ventricular noncompaction
cardiomyopathy is a rare cardiomyopathy characterized by thickening of the left
ventricular wall with the appearance of 2 layers: a thick noncompacted
endocardial layer and a thin compacted epicardial layer. The thick endocardial
layer consists of prominent trabeculae and deep intratrabecular recesses, which
are in continuity with the left ventricular cavity. The cardiomyopathy is the
result of failure of compaction of normal myocardium between weeks 5 and 8 of
fetal life.
Patient presentation is highly variable depending on the
severity of left ventricular involvement. Patients with mild forms may be
completely asymptomatic or present later in life. Symptomatic individuals are
often diagnosed early with a median age at diagnosis of 7 years with symptoms
related to congestive heart failure. Patients have low-ejection fractions with
cases of both systolic and diastolic dysfunction as described in the
literature. Arrhythmias are common with ventricular tachyarrhythmias in up to 50%
of patients and atrial fibrillation in up to 25% of patients. As a result,
patients may also present with embolic events due to the development of thrombi
within the left ventricle.
Diagnosis is often made by echocardiography with 4 echocardiographic features: 1) Absence of coexisting
cardiac abnormalities; 2) Maximal-end systolic ratio of non-ompacted to
compacted layers >2:1: 3) Predominant localization to the midlateral,
apical, and midinferior regions of the left ventricle; and 4) color Doppler
evidence of deep perfused intertrabecular recesses. Cardiac MRI is becoming the
imaging modality of choice as it provides a more complete depiction of cardiac
morphology with better visualization of the cardiac apex. Using MRI, the
imaging features are essentially the same as echocardiography, except a ratio
of noncompacted myocardium to compacted myocardium >2.3 is used which yields
a sensitivity of 86% and specificity of 99% for noncompaction cardiomyopathy. Additional
imaging features include a dilated left ventricular cavity with diffuse global
hypokinesis resulting in a decreased left ventricular ejection fraction. In up
to 40% of patients there is involvement of the right ventricle as well. Late
gadolinium enhancement may occur anywhere within the left ventricle. Results of
early research suggest a more severe disease state in patients with late
gadolinium enhancement as compared to patients without late gadolinium enhancement.
Treatment of noncompaction cardiomyopathy is similar to that of other cardiomyopathies, including angiotensin-converting-enzyme (ACE) inhibitors, beta blockers, and anticoagulation. Patients often undergo pacemaker placement due to the high
incidence of arrhythmias and risk of sudden death.
- Dodd JD, Holmvang G, Hoffmann U, et al. Quantification of left ventricular noncompaction and trabecular delayed hyperenhancement with cardiac MRI: correlation with clinical severity. AJR Am J Roentgenol. 2007;189:974-980.
- Jassal DS, Nomura CH, Neilan TG, et al. Delayed enhancement cardiac MR imaging in noncompaction of left ventricular myocardium. J Cardiovasc Magn Reson. 2006;8:489-91.