Cardiovascular Journal of Africa: Vol 25 No 5 (September/October 2014)

CARDIOVASCULAR JOURNAL OF AFRICA • Volume 25, No 5, September/October 2014

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AFRICA

mainly in the apical, lateral and anterior walls, and mid-septal

portions of the left ventricle (Fig. 1A, B, C). There were no

co-existing cardiac abnormalities detected.

Non-compacted areas of the left ventricle were easily

distinguished from healthy segments by magnetic resonance

imaging (Fig. 2A). Coronary angiography revealed normal

coronary anatomy. The inter-trabecular recesses in the LV

wall were demonstrated by ventriculography (Fig. 2B). In

addition, sustained ventricular tachycardia was induced during

electrophysiological study (Fig. 3). Medical cardioversion with

1 200 mg iv amiodarone was administered to convert the

arrhythmia to sinus rhythm to haemodynamically stabilise the

patient.

The patient was put on amiodarone and anticoagulant

therapy in addition to optimal heart failure treatment consisting

of metoprolol 50 mg, ramipril 2.5 mg, furosemide 40 mg and

spironolactone 25 mg po qd. After implantable cardioverter-

defibrillator (ICD) implantation, the patient was discharged

and advised to continue the treatment. We also recommended

echocardiographic evaluation of her first-degree relatives,

considering the familial association of INVM.

Discussion

The incidence of non-compaction cardiomyopathy is about

0.05% in adults. Non-compaction of the LV myocardium is the

result of an arrest in compaction of myocardial fibres during

embryogenesis. It is most frequently observed in the left ventricle

but the right ventricle may also be affected. The disorder is

diagnosed by two-dimensional echocardiography.

Computed

tomography and magnetic resonance imaging (MRI) have

been reported as useful diagnostic tools in INVM; they may

be of value, especially in patients with poor image quality on

echocardiography.

The four previously established morphological criteria

for echocardiographic diagnosis of INVM is as follows; (1)

appearance of at least four prominent trabeculations and deep

inter-trabecular recesses; (2) appearance of blood flow from the

ventricular cavity into the inter-trabecular recesses as visualised

by colour Doppler imaging; (3) the segments of non-compacted

myocardium mainly involve the apex and the inferior mid-

and lateral mid-LV wall and typically show a two-layered

structure with an end-systolic ratio greater than two between

the non-compacted sub-endocardial layer and the compacted

sub-epicardial layer; and (4) absence of co-existing cardiac

abnormalities.

In a study by Jenni

et al

., the prevalence of non-compacted

cardiomyopathy was determined at 0.04% in five years.

Ventricular non-compaction was an isolated finding in 74% of

the cases and non-compacted ventricular myocardium involving

only the left ventricle was 62%. While 77% of patients were in

Fig. 1.

Transthoracic two-dimensional parasternal long-axis

(A), parasternal short-axis (B), and apical four-chamber

ventricle with multiple trabeculae and inter-trabecular

recesses in the lateral, apical, anterior and mid-septal

areas. Appearance of blood flow from the ventricular

cavity to these deep trabeculae was detected by colour

Doppler imaging (D).

Fig. 2.

(A) Multiple deep trabeculae and inter-trabecular recesses of the left ventricle can also be demonstrated by MRI. (B) Left

ventriculogram of the patient showing inter-trabecular recesses, especially in the left ventricular apical and lateral wall.