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CARDIOVASCULAR JOURNAL OF AFRICA • Volume 28, No 4, July/August 2017
AFRICA
209
Despite the lack of evidence to pinpoint the aetiology of
EMF, some progress has been made in the diagnosis as well as in
medical and surgical treatment. In earlier reports, the diagnosis
of EMF was based on post mortem findings and clinical
correlations but presently echocardiography is the standard
diagnostic tool. Recently, cardiac magnetic resonance imaging
(CMR) emerged as an additional tool to define the primary
and secondary structural and functional abnormalities of EMF.
CMR with gadolinium enhancement seems ideally suited to
diagnose this condition and monitor response to medical and/
or surgical therapy.
16
Medical treatment of EMF entails reduction of fluid overload
with diuretics and preload with nitrates. Rate and rhythm control
may help in patients presenting with tachyarrhythmias, including
atrial fibrillation. Surgical treatment of EMF was practiced
for many years and consisted of removal of fibrosis from both
ventricles, and atrioventricular valve replacement. Mitral or
tricuspid annuloplasty has had only limited success.
17
In Sudan, EMF was first described by O’Brien in 1954 and
later by El Hassan, who had carried out post mortem studies
in 133 cases of cardiovascular deaths. Among these, six out of
13 cases of cardiomyopathy had EMF affecting both left and
right ventricles, with fibrosis that involved the endocardium and
subendocardial tissues and covering the apex, papillary muscles
and posterior ventricular wall, leading to atrioventricular valve
dysfunction.
18,19
The objective of our study was to document the current
frequency of EMF in Sudan by identifying and selecting cases
from patients attending our echocardiography clinics in four
different hospitals, and creating an EMF registry. However
during the process of acquisition and analysis of images, it
emerged that there were new echocardiographic features that
had not been reported before. These findings are presented and
discussed below.
Methods
This study is a prospective, descriptive study, which started
in January 2007 and is on-going. Patients attending our
echocardiography sessions at Amal National Hospital from
2007 to 2009, and the Academy Teaching and Yastabshiroun
Hospitals from 2010 to 2011 were included; however the majority
of the selected patients were enrolled from the Heart Clinic in
Khartoum, Sudan. Permission for the study was obtained from
the ethics committees in the four centres and informed verbal
consent was obtained from each patient.
Transthoracic echocardiography using Mylab30 (Esaote,
Italy) was performed by SIK on all selected patients, using
the American Society of Echocardiography (ASE) standards.
20
Additional information was obtained from the
Echo Manual
by
Oh, Seward and Tajik.
21
The following standard echocardiographic views were used:
parasternal long-axis (PLAX), short-axis (SAX), M-mode, apical
two-, four- and five-chamber views (AP2, AP4, AP5) and the
apical long-axis view (APLX). Additionally, a modified APLX
view, obtained by angulating the probe medially and rotating
counter-clockwise to focus on the recess between the posterior
papillary muscle and the posterior mitral valve leaflet was used.
The diagnosis of EMF was made on cases that fulfilled the
following echocardiographic features and definitions:
•
Generalised endomyocardial thickening and fibrosis of the
apex, ventricular walls and papillary muscles, and atrioven-
tricular (AV) valve incompetence.
•
Obliteration of the ventricular cavity by fibrous tissue,
defined as left ventricular (LV) diastolic volume less than
40 ml, measured by the modified Simpson’s rule in AP4 view
and right ventricular (RV) size less than 20 mm, measured by
the mid-RV diameter in the AP4 view.
•
Left atrial (LA) volume was measured with the biplane
method of disks (modified Simpson’s rule) from AP4 and
AP2 views at ventricular end-diastole. Huge left atrium was
defined as atrial volume of more than 70 ml.
•
Right atrium (RA) was quantified from the apical four-cham-
ber view. The minor-axis diameter was measured according to
ASE recommendations.
19
Right atrial dilatation was assumed
when the mid-axis diameter was more than 5.0 cm.
Diagnosis was made from a detailed initial examination and
ascertained by two review examinations, carried out during the
first four weeks after the case was identified.
Additional information was derived from targeted history,
clinical examination, 12-lead electrocardiogram (ECG), chest
X-ray and complete blood count, including total blood count,
differential white cell count and absolute eosinophilia (
>
600
cells/
μ
l).
Results
Out of 4 332 cases studied, 23 (0.5%) were found to have features
of EMF. Of these 23 cases identified, two were from Amal
Hospital, two from Yastabshiroun Hospital, five from Academy
Teaching Hospital and 14 cases were from the Heart Clinic in
Khartoum. Females constituted 52% and the age range was 24
to 67 years. All patients presented with dyspnoea grades III–IV,
and advanced heart failure with gross fluid overload was seen in
54% of cases and ascites was seen in 30%.
ECG findings were non-specific; sinus tachycardia was found
in 22% of patients, atrial abnormality in 43%, first-degree heart
block in 39% and atrial fibrillation in 13% of patients. Chest
X-ray findings were also non-specific and showed cardiomegaly
in 92% of patients.
Haematological findings included absolute eosinophilia in
three patients and five cases had iron deficiency. EMF was
biventricular in 53%, left ventricular in 29% and right ventricular
in 18% of cases. Echocardiographic features of EMF are
summarised in Table 1.
Table 1. Frequencies of echocardiographic
features of EMF (
n
= 23)
Echocardiographic features
Percentage of patients
Apical fibrosis
100
Ventricular wall fibrosis
100
Atrial enlargement
100
Atrioventricular valve regurgitation
100
Ventricular cavity obliteration
91
Pericardial effusion
87
Endocardium fibrous shelf formation
82
Restrictive flow pattern
76
Ascites
30
Thrombus formation
6