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717

Case Report

Noncompaction Dewey

J. Conces,

Jr.,1

of Ventricular

Thomas

Ryan,2

and

Robert

Myocardium:

D. Tarver1

the apical, anterior, lateral, and inferior portions of the left ventricle. The distal portion of the intraventncular septum also was involved; the proximal portion was spared. The thickened wall was made up of two zones of differing density. The outer portion of the

During early embryonic development, the heart consists of a trabecular network of spongelike myocardium [1 ]. The intertrabecular spaces communicate with the chambers of the heart. As the heart develops, the myocardium becomes compacted and the meshlike pattern disappears. Failure of normal myocardial differentiation results in noncompaction of the myocardium, a rare disorder in which the trabecular myocardium persists. We report a case of myocardial noncompaction involving the left ventricle that was imaged with CT.

involve

ventricular

wall to that

in thickness

A 44-year-old for

showed

woman

5 days

had numbness

before

admission.

and weakness

CT examination

and

sonography

showed

of

the

a left

carotid

ventricle

artery

mass.

were

Findings

of a band

therapy

This

zone

of uniform was

tissue

with

a density

approximately

2.4 cm in the basilar region to 3.0 cm in the apex.

was given

anticoagulants

and discharged

to continue

as an outpatient.

normal.

The

Discussion

The persistence of trabeculated myocardium has been reported involving both the right and left ventricles [2, 3]. Reported cases are frequently associated with other cardiac anomalies, including pulmonary atresia and coronary artery abnormalities [3, 4]. No associated cardiac anomalies were identified in our patient, although the presence of coronary artery anomalies has not been excluded. Previously reported patients with isolated left ventricular involvement ranged from 1 1 months to 22 years old [2, 5]. Our patient, at 44 years old, was significantly older than previously reported patients. Patients may be asymptomatic or exhibit signs and symptoms of heart failure, arrhythmias, or systemic emboli [2, 5]. The cause of the decreased left ventricular function is not clear, but may be related to faulty intramural perfusion due to the presence of the trabeculations

was

on

Doppler

patient

transferred to our institution for evaluation of the cardiac By the time of transfer, the patient had experienced neurologic recovery. On cardiac examination, a short

was

mass. significant midsystolic

was present with multiple systolic clicks. An ECG showed left ventricular hypertrophy. A chest radiograph showed left ventncular prominence consistent with left ventricular hypertrophy. Two-dimensional (2-D) echocardiography showed marked thickmurmur

ening and trabeculation ventricle

(Fig.

myocardium.

of the

of the apical,

1 A). Cystlike

Doppler

tic areas. A contrast-enhanced left ventricular

examination

areas

lateral, were

and inferior seen

demonstrated

within

walls of the the

(X-64).

Department 156:717-718,

of Internal

thickened

flow within

the cys-

thoracic CT scan showed marked thickening wall (Fig. 1 B). The thickening was seen to

Received October 19, 1990; accepted after revision November 1 Department of Radiology, Indiana University Medical Center,

AJR

from

The patient

in her left of her head

an infarct in the right panetal lobe. Echocardiography

performed

2

of muscle.

Report

hand

left

consisted

0.7 cm thick. More centrally, the appearance of a wider inner zone suggested that it was composed of a mixture of contrast-enhanced blood and soft tissue with a density similar to that of muscle. This region measured similar

physical

Case

CT Appearance

Medicine,

Indiana

University

April 1991 0361-803x/91/1564-0717

Medical

29, 1990. 926 W. Michigan Center,

© American

St., Indianapolis,

Indianapolis, Roentgen

IN 46202.

Ray Society

IN 46202-5253.

Address

reprint

requests

to D. J. Conces,

Jr.

718

CONCES

ET AL.

AJR:156,

April 1991

Fig. 1.-A, Apical four-chamber echocardiogram shows thickening and trabeculation of left ventricular free wall and septum. LV = left ventricle, RV = right ventricle. B, Contrast-enhanced CT scan through level of left ventricle. A thin outer zone of compact myocardium is easily distinguished from inner

zone of trabeculated

noncompacted

myocar-

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dium.

or decreased diastolic function due to abnormal left ventricular compliance. The cause of the ventricular arrhythmias also is unclear, but these arrhythmias can be fatal. The trabecular recesses present in the noncompacted ventricle predispose to the development of mural thrombi. The thrombi may subsequently break free and form an embolus in the systemic circulation. Chin et al. [2] reported eight patients with left ventricular involvement, four of whom had dysmorphic facies. Our patient presented with a cerebral embolus but had no signs or symptoms ofleft ventricular dysfunction, arrhythmias, or abnormal facies. Chest radiographs may appear normal or may show changes of congestive heart failure when left ventricular dysfunction is present [2, 5]. In our patient, the chest radiograph showed left ventricular prominence, reflecting the increased thickness of the left ventricular wall. Ventriculography, if performed, shows a honeycombed appearance of the inner contour of the involved ventricle [5]. Echocardiography, which is diagnostic of the disorder, reveals large prominent trabeculations and deep intertrabecular recesses [2]. The trabeculations are least numerous near the mitral valve, with the thickness of the wall and the depth of the intertrabecular recesses greatest at the apex. In this case, Doppler examination revealed flow within the blood-filled in-

tertrabecular recesses, suggesting communication between these recesses and the ventricular chamber. The CT findings of this disorder are diagnostic also and mirror the findings of echocardiography. The ventricular wall is composed of two layers. The outer layer consists of a thin layer of compacted myocardium that is of a uniform density similar to that of muscle. Within this is a much thicker layer that appears to represent a mixture of contrast-enhanced blood and soft tissue. This represents the trabeculated myocardium with ventricular blood filling the intertrabecular recesses. REFERENCES 1 . Carison

BM.

Patten’s

foundations

of embryology,

5th

ed.

New

York:

McGraw Hill, 1988:586-627 2. Chin TK, Perloft JK, Williams RG, Jue K, Mohrmann R. Isolated noncompaction of left ventricular myocardium: a study of eight cases. Circulation 1990;82:507-513 3. Williams RR, Kent GB, Edwards JE. Anomalous cardiac blood vessel communicating with the right ventricle. Arch Pathol 1951;52:480-487 4. Dusek J, Ostadal B, Duskova M. Postnatal persistence of spongy myocardium with embryonic blood supply. Arch Pathol 1975;99:312-317 5. Jenni R, Goebel N, Tartini R, Schneider J, Arbenz U, Oelz 0. Persisting myocardial sinusoids of both ventricles as an isolated anomaly: echocardiographic, angiographic, and pathologic anatomical findings. Cardiovasc Intervent Radio! 1986;9: 127-1 31