Endomyocardial fibrosis is a cardiac disease that with a global incidence but more preponderant in the Tropic. The disease has been known for more than 70 years, in this review, Dr. Daniel Faithful Miebaka provides a detailed presentation of the condition and some tropical insights.

1. By Dr. Daniel Faithful
Internal Medicine.

2.  Introduction
 Background
 Definition of Terms
 Epidemiology
 Pathogenesis
 Clinical Features
 Management
 Prognosis
 Conclusion
 References

3.  In discussing endomyocardial fibrosis it is important to appreciate the anatomy of
the structures involved and to trace the schema from which the disease state
flows.
 Endomyocardial Fibrosis can therefore be discussed as a subset of obliterative
type of restrictive cardiomyopathy. The break down of the classification from
cardiomyopathy in general becomes useful in distinguishing the condition from
other possible variants and provides a basis for the understanding of it’s
differentials.
 Endonyocardial fibrosis is a relevant subject in our clime(tropics) as we would find
out in later parts of this presentation.

4.  It has been described as an idiopathic disorder characterized by a complex of
restrictive cardiomyopathy and fibrotic changes in the apical myocardium of the
right and left ventricles, it has been reported in tropical and subtropical
regions¹²(Dato, 2015 and Hesarur slides are). In fact, a study described it as a
disease of rain forest belt of Africa, while another classified it under
cardiovascular diseases of less developed countries³(falase 1983).
 The clinical manifestations this follow the pattern in restrictive cardiomyopathy
showing reduced ventricular filling and subsequently a right or left sided heart
failure. There is usually a finding of atrioventricular regurgitation.
 The disease has an endemic distribution pattern where it is a major cause of
morbidity and mortality when severe where it has a poor prognosis.

5.  The disease was unreported till 1946, when Bedform and Konstam published
findings from post mortenm analysis of 40 west African soldiers who served in the
World War II.
 They attributed the disease to an unknown aetiology and the title of their paper
was Heart Failure of Unkown Origin in Africans published in the British Heart
Journal.
 It was in the next year that Jack N.P. Davies identified Endomyocardial fibrosis
and coined the word after studying the condition in Uganda⁴⅝( Davies JNP 2018,
Gene Buhkhan) .
 In 1954, Davies et al delineated the clinico-pathological features of the disease
and the disease came to be known as Davies Disease²6(slideshare and Ball JD,
Williams, Davies 1954).

6.  The disease occurs worldwide but mainly in the tropical and subtropical regions,
especially in the editorial region which has 90% if the disease burden. It has been
reported in 11 Africa countries including Nigeria, Mozambique, Kenya, Tanzania,
Gabon, Uganda, Ivory Coast, Sudan, Cameroon, Congo( 7-15)16(Mocumbi Falase).
 It also occurs in India, China, Brazil and Columbia 17(Guiterrez 2017). It is
uncommon in Northern and Southern Africa³(Falase).
 It is the most common type of restrictive cardiomyopathy in tropical regions and
worLdwide. It is the fourth most common type of cardiac disease in adults in equitorial
Africa.
 In 2008, the prevalence of the disease was as high as 20% in Mozambique (Mocumbi et
al). The findings are consistent with reported data from Kampala were it is seen in
20% of heart disease referred echocardiography(Gene Bukhman)

7.  There is reported improvement in the prevalence of EMF, Akinwusi and Odeyemi
showed that there is a changing pattern in reporting the prevalence in the
southwestern region of West Africa. The prevalence was 2 in 100 medical patients
and double that when cardiac patients are reviewed.(Akinwusi and Odeyemj,
2012)
 This shows a steep reduction in the prevalence that was reported in the 1960s and
1970s. Improvements in health care, childhood nutrition, living standards and
burden of infections and worm infestations have been implicated as plausible
reasons.

11.  It is important to note that the distribution of EMF in hot and humid regions, like
Nigeria and Uganda.
 For instance the disease is only found in the hot and humid regions which
correspond to places with rainforest vegetation(18-22). There was no patient found
with the disease after a review of cardiovascular admission in Zaria’s referral
center in the 1970s

12. 

13.  Endomyocardial fibrosis is reported more in teenagers, between 10-19 years of
life(23).
 A study done in Uganda about two decades ago, showed that showed a bimodal
peak in the age distribution at 10 and 30 years respectively(24 Rutakingirwa).
The gender distribution in Uganda, follows two patterns; in childhood there is
equal distribution and for adults a female predilection that is twice as much for
their male counterparts(24).
 The situation in Nigeria is the reverse, studies show a 2:1 male preponderance,
while others done in Ibadan show no predilection³.
 The disease has not been observed in children under 4 years, However it has been
reported in a 4 month old with Left ventricular inflow tract obstruction.
 It has also been reported in individuals above 70 years of age.

15.  EMF is rarely reported in upper and middle class but is predominantly seen in
lower socioeconomic class³. In Uganda, it was seen majorly in the Burundi and
Ruanda tribe composed mainly of poor migrant labourers but less common in
Ganda tribe that is more affluent Shaper and Hutt(1968).
 In Nigeria earlier studies done in the 1960s and 1970s showed that the disease
was more common among the Ijebu ethnic group, however most of these studies
were done in Ibadan, when this is juxtaposed against the backdrop of the ethnic
group that makes the general population of patients attending routinely, this does
not indicate any or predisposition to ethnicity³.
 It is important to note that the disease is well reported amongst Europeans who
have previously lived in Africa, and contrary to expectations among caucasians or
asians who gave never lived in Africa(brockington-3 more).

16.  Endomyocardial fibrosis as the name implies suggests fibrotic changes(collagen
deposition and fibroblast proliferation) involving two cardiac structures; endocardium
and the myocardium. How these changes will go ahead to cause a sequelae of
catastrophic proportions will be dealt with under this heading.
 The disease starts off following a yet to be clearly understood process, which leads to
scareing of the endocardium and inner third of the myocardium by patchy fibrosis³.
These changes begin from the apex of the ventricles and then spreads to involve other
areas leading to reduction in reduced compliance of a restrictive variety.
 The condition can go ahead to involve the atrioventricular valves due to involvement
of the papillary muscles and chordae tendinae. The tethering of the chordae tendinae
results in one of the valve (posterior) being constantly open leading to atrioventricular
incompetence; mitral and tricuspid regurgitation. The condition spares the outflow
tract and the anterior leaflet of the mitral valve.
 It should be noted that the distribution of the fibrosis varies and five types have been
sufficiently described by Sharper in 1968 and corroborated by M.S. Hutt two years
later.

19.  Classes of tissue involvement in Endomyocardial Fibrosis
1. Only apical ventricular involvement.
2. Affects the apex and the valvular area.
3. Only the valvular region.
4. Isolated lesions in the apex and the valvular area.
5. Patchy lesions that progressively involved areas EXCEPT the valves and the
apex.
From the foregoing, it can thus be deduced that Type 2,3,4 will typically present
with atrioventricular incompetence, while type 1 and 5 maybe asymptomatic and
often missed.

20.  The disease is sometimes classified under obliterative type cardiomyopathy. This
is because as the disease progresses the ventricular cavity can become ‘obliterated’
by fibrous tissue and superimposed thrombus. This gives rise to reduced diastolic
filling, and concurrently impair ventricular systolic contraction thereby reducing
stroke volume and cardiac output.
 The disease can either affect one or both ventricles and become complicated by
pericarditis, pericardial effusion and high diastolic pressure can ultimately less to
congestion in the pulmonary and systemic venous system(Oxford).
 It follows that these are progressive changes in the setting of chronic illness.
 What begs the question is what happens at the acute stage.
 There is no general consensus that describes the changes at the acute phase,
however Sharper and Olsen make useful attempts that have now become adopted
by several authorities in understanding the disease(Shaper 1974 and Olsen 1975).

21.  According to Shaper, in the acute phase myocardial lesions are covered by soft, spongy
and greyish-green layer of thrombus.
 It is described in three stages;
1. An acute endomyocardial lesion is covered by overlying fibrinous deposits.
2. In this stage there is now an adherent thrombi.
3. The thrombi is incorporated into a fibrosed and contracted ventricle.
Olsen tries to describe the condition in three phases and what occurs at the background.
1. Eosinophilic infiltration of the myocardium and necrosis of the subendocardium.
First five weeks and resembles myocarditis
2. Thrombus formation over the lesion and reduction in inflammatory process.
Observed after 10 months.
3. Replacement of the endocardium by collagenous fibrosis. Observed after several
years.

22.  Despite the tremendous interest in the subject of endomyocardial fibrosis evident in
abundance of studies, the disease has no known aetiology.
 However several postulates have implicated the following;
 Eosinophilia
 Nutritional factors
 Serotonin
 Vitamin E deficiency
 Immunological
 Parasitic Infections, Eosinophilia
 Rheumatic Heart Disease
 Dilated Cardiomyopathy
 Cardiac Lymphatics Obstruction

23.  Epidemiological studies into the prevalence of EMF have suggested that there is a
high burden of the disease in developing countries were poverty and malnutrition
are common problems³.
 The drawbacks to postulate this revolves around two epidemiological findings³
1. That the disease has been reported among well nourished caucasians residing
in Africa
2. Also, there are variations in local population like the confinement of the disease
in rainforest regions or differences observed based on ethnicity.

24.  In addition to other hormones produced by carcinoid syndrome serotonin is
excessively produced and has been shown to cause a typical cardiac lesion