CARDIOVASCULAR JOURNAL OF AFRICA • Vol 21, No 3, May/June 2010
AFRICA
161
tions of cardiac sarcoidosis (23%).
7
Sudden death secondary to
ventricular fibrillation or complete AV block accounts for 25 to
67% of deaths.
6,10
Sarcoid involvement of the myocardium can precipitate heart
failure, both systolic and diastolic. Heart failure is the cause
of death in 25 to 73% of patients with cardiac sarcoidosis.
6,10
Valvular abnormalities are common due to papillary muscle
granulomatous infiltration and fibrosis (particularly the mitral
valve), however, granulomatous disease of the valve leaflets
themselves has been described.
20
Pericardial,
21,22
aortic root
23,24
and even epicardial coronary artery
18,25
sarcoid involvement have
all been described in the literature.
Our patient had conduction abnormalities (AV conduction
delay, frequent PVCs and sustained ventricular tachycardia) as
well as both systolic and diastolic dysfunction and mitral regur-
gitation secondary to granulomatous infiltration.
Evaluation of patients with sarcoidosis for cardiac
involvement
Numerous modalities exist to evaluate for cardiac involvement of
sarcoidosis (Table 2). ECG abnormalities such as those described
above or simulated pathological Q waves are present in 70%
of patients with sarcoidosis.
9
Echocardiographic examination
can reveal: ventricular aneurysms, valvular insufficiency, and
segmental or global hypokinesis.
26
Radionucleotide examina-
tion has also been widely performed.
27
Areas of decreased thal-
lium-201 uptake correspond to infiltration. However, defects
decrease in size during exercise in contrast to ischaemic areas.
PET is more sensitive in detecting early inflammation due
to sarcoidosis.
28
CMR demonstrating late gadolinium enhance-
ment has a sensitivity of 100% and specificity of 78%,
29
with
the uptake seen primarily in the basal and lateral segments and
mostly in the mid portion of the myocardium and epicardium.
This contrasts with uptake due to infarction, which is primarily
in the endocardium. Also commonly seen, again, are wall-motion
abnormalities and myocardial thinning. In one study, normalisa-
tion of delayed gadolinium enhancement correlated with clinical
improvement and clearing of sarcoidosis.
29
On ECG (Fig. 2), our patient demonstrated not only the
conduction abnormalities, but also Q waves inferiorly indicative
of an old infarction. CMR (Fig. 3) was also suggestive of multi-
vessel coronary artery disease, however, delayed gadolinium
enhancement of the epicardium, myocardium and endocardium
was suggestive of myocarditis or infiltrative process. The latter
suggestion was confirmed by a normal cardiac catheterisation.
Diagnosis
Granulomas of the pericardium and endocardium have been
reported, but the myocardium is more frequently infiltrated.
Most commonly involved are the left ventricular free wall and
papillary muscles, followed by the basal aspect of the ventricular
septum.
6
The gold standard of sarcoid diagnosis is tissue biopsy,
although this has been debated.
30
Endomyocardial biopsy (EMB)
carries a high false-negative rate due to sampling error, as
granulomatous infiltration is non-homogenous and more often
more basilar, however biopsies are usually taken from the apex
and septum. Furthermore, EMB is most often obtained from
the right ventricle whereas left ventricular involvement is more
common in sarcoidosis. Endomyocardial biopsy guided by find-
ings on CMR has been used in patients with elevated troponin-I
and absence of significant obstructive coronary disease, and it
improved the diagnostic yield of either modality singly (most
common diagnosis was myocarditis).
31
The Japanese Ministry of Health and Welfare guidelines for
the diagnosis of cardiac sarcoidosis are based on either patho-
logical confirmation or a constellation of clinical findings. The
histological diagnosis requires the presence of non-caseating
granulomas, whereas the clinical diagnosis requires the presence
of conduction abnormalities or ventricular arrhythmias plus at
least one of the following: abnormal wall motion, wall thicken-
ing, left ventricular dilatation; perfusion defect; heart failure; or
interstitial fibrosis or more than moderate cellular infiltration on
histological examination.
16
Although EMB was negative for granulomatous disease
in our patient, his physical examination and imaging findings
certainly still suggested cardiac sarcoidosis, and lung biopsy
revealed pathognomonic non-caseating granulomas. As this case
illustrates, reliance solely on cardiac biopsy is very low yield
and diagnosis of cardiac sarcoidosis requires appreciation of the
overall clinical picture.
TABLE 1. COMMONEST CARDIAC
MANIFESTATIONS OF SARCOIDOSIS.
6-9,14,40
Conduction system
%
AV block
10–30
Frequent PVCs
30
VT
20
SVT
20
Heart failure
Depressed LVEF
10–70
Valvular insufficiency
20
LV diastolic dysfunction
10–30
Dilated LV
30
LV wall abnormalities
5–25
Sudden cardiac death
30–65
AV
=
atrioventricular; EF
=
ejection fraction; LV
=
left ventricle; PVC
=
pre-ventricular contraction; SVT
=
supraventricular tachycardia.
TABLE 2. EVALUATION FOR SARCOID
INVOLVEMENT OF THE HEART
Modality
Potential findings
ECG
Atrioventricular conduction abnormalities, PVCs,
VT, Q waves
Echocardiogram Segmental or global hypokinesis, systolic or
diastolic dysfunction, ventricular aneurysms,
abnormal wall thickness, valvular insufficiencies
Myocardial
perfusion
Decreased uptake of thallium-201 or techni-
cium-99, which improves during exercise
CMR
Late gadolinium enhancement of basal and
lateral free-wall myocardium and epicardium,
regional or segmental wall-motion abnormalities,
focal abnormalities in wall thickness
PET
Increased uptake of F-FDG corresponds to areas
of infiltration which parallels peri-hilar uptake
CMR
=
cardiac magnetic resonance imaging; F-FDG
=
F-fluorode-
oxyglucose; PET
=
positron emission tomography; PVCs
=
pre-
ventricular contractions; VT
=
ventricular tachycardia.
