Eduardo Arantes Nogueira, Osvaldo Massaioshi Veti, Walla sse Rocha Vieira
T h e ap ical v en tricu lar lesio n in C h ag as' h eart d isease
Discipline of Cardiology, Department
of I nternal Medicine,
Universidade Estadual de Campinas - Sao Paulo, Brazil
A pical lesions of the left ventricle, ranging from endocardial thickening to aneurysm s, are com m only found in C hagas' heart disease. These abnorm alities can be identified by ventriculography, tw o-dim ensional echocardiography and radioisotopic studies. G enerally, clinical m anifestations are lim ited to arrhythm ias and throm boem bolic. The lesions are usually sm all and apparently do
not playa role in ventricular dysfunction.
U N ITE R M S : C hagas' heart disease.
IN TR O D U C TIO N
N
. o rm a lly ,s h e ll a n dth e le ft v e n tric u la ris fo rm e d b y th ea p e x h a s a s h a p e o f ain te rw e a v in g o f e p ic a rd ia l a n d e n d o c a rd ia l fib e rs c re a tin g a nin te rn a l d o u b le v o rte x , a n d e x te rn a l. W h e n c u t o f th e
v e n tric le is c u t lo n g itu d in a lly , s h o w s a p ro g re s s iv e th in n in g
o f th e p e riv o rtic a l v e n tric u la r w a lls . T h u s , th e c e n te r o f
th e v o rte x o f th e n o rm a l le ft v e n tric u la r m e a s u re s o n ly 1
to 2 m m th ic k , b e in g fo rm e d a lm o s t o n ly b y th e a tta c h m e n t
o f th e e n d o c a rd ia l a n d e p ic a rd ia l la y e rs . T h e a p ic a l le s io n
o r a p ic a l a n e u ry s m in C h a g a s ' h e a rt d is e a s e is a v e ry
p e c u lia r a b n o rm a lity o f th e le ft v e n tric u la r a p e x ; le s s
fre q u e n tly , it c a n a ls o b e fo u n d in th e rig h t v e n tric u la r
Address for correspondence:
Eduardo Arantes Nogueira
Disciplina de Cardiologia, Faculdade de Ciencias Medicas
Universidade Estadual de Campinas - Caixa Postal 6 1 4 2
-Campinas - Sao Paulo - Brasil - CEP 13084-100
a p e x . T h is le s io n w a s firs t o b s e rv e d in n e c ro p s ie s a n d w a s
d e te c te d c lin ic a lly m u c h la te r b y c in e v e n tric u lo g ra p h y
(1 2 ,2 4 ). A v e ry c h a ra c te ris tic le s io n w ith h ig h p re v a le n c e
a m o n g p a tie n ts w ith C h a g a s ' h e a rt d is e a s e , it tu rn e d o u t
to b e a c a rd in a l s ig n o f th e d is e a s e a n d , b y s o m e , a
p a th o g n o m o n ic le s io n . Its p a th o g e n e s is is v e ry d is p u te d
a n d it h a s d e s e rv e d n u m e ro u s s tu d ie s re p re s e n te d b y a n
e x te n s iv e lite ra tu re .
Pathological Anatomy
C h a ra c te ris tic a lly , th e re is a th in n in g o f th e a p ic a l
re g io n w ith fo rm a tio n o f a n a n e u ry s m , th a t is , a d ila ta tio n
o f th e e n d o c a rd ia l a n d e p ic a rd ia l w a lls (2 4 ). S o m e tim e s
th e a re a is s o th in th a t c a n b e id e n tifie d in n e c ro p s y s tu d ie s
b y tra n s illu m in a tio n o f th e le ft v e n tric le . H o w e v e t o th e r
c a s e s , th o u g h , p re s e n t o n ly a s m a ll in te rn a l d ila ta tio n o f
th e a p e x , in v o lv in g th e p e riv o rtic a l m u s c u la tu re o r o n ly
a n e n d o c a rd ia l th ic k e n in g ; th u s th e te rm a p ic a l le s io n
e n c o m p a s s a w id e r c o n c e p t (6 ).
O liv e ira e t a l. (2 4 ) n o te d th a t th is le s io n w a s p re s e n t
in 5 2
%
o f 1 1 5 3 n e c ro p s ie s o f p a tie n ts w ith C h a g a s 'H e a rtD is e a s e ; o f th e s e , 8 2
%
w e re p re s e n t in th e le ft v e n tric le ,in 9
%
in th e rig h t v e n tric le , a n d in 9%
in b o th c h a m b e rs .T h e p r e s e n c e o f a p i c a l l e s i o n d i d n o t c o r r e l a t e w i t h a g e ( 1 0 t o 8 9 y e a r s ) n e i t h e r w i t h h e a r t w e i g h t . I t s f r e q u e n c y i n
p a t i e n t s w i t h s u d d e n d e a t h w a s s i m i l a r t o t h o s e w h o d i e d i n c o n g e s t i v e h e a r t f a i l u r e . A p i c a l t h r o m b u s w a s f o u n d i n 2 5 % o f c a s e s . I n s o m e c a s e s a s i m i l a r a b n o r m a l i t y w a s
f o u n d i n t h e l e f t v e n t r i c u l a r b a s e .
T h i s l e s i o n i s d i f f e r e n t f r o m m y o c a r d i a l i n f a r c t i o n d u e t o c o r o n a r y o c c l u s i o n , w h i c h l e a v e s a m o r e t h i c k
f i b r o u s s c a r . S o m e t i m e s t h e r e i s o n l y a n e n d o c a r d i a l t h i c k e n i n g b u t t h e s e c a s e s a r e d i f f i c u l t t o d i f f e r e n t i a t e f r o m e n d o c a r d i a l t h i c k e n i n g f o u n d i n l a r g e a n d h i p o k i n e t i c h e a r t s a s i t c a n b e s e e n i n d i l a t e d c a r d i o m y o p a t h y .
Ventriculographic
studies
C o n t r a s t e d v e n t r i c u l o g r a p h y i s s t i l l t h e m o s t s e n s i t i v e
m e t h o d f o r a p i c a l ' l e s i o n i d e n t i f i c a t i o n b u t i t h a s t h e d i s a d v a n t a g e o f b e i n g a n i n v a s i v e p r o c e d u r e . W i t h t h i s t e c h n i q u e o n e c a n e v a l u a t e t h e l e s i o n s i z e ; f o r m a n d k i n e t i c a n d i d e n t i f y t h e p r e s e n c e o f t h r o m b u s . T h e l e s i o n a p p e a r s a s a n a p i c a l a k i n e s i a / d y s k i n e s i a , b e s t s e e n i n l e f t a n t e r i o r o b l i q u e v i e w . I n s e v e r a l s e r i e s i t a p p e a r s w i t h a m e a n f r e q u e n c y o f 5 0 % , b u t t h e r e i s s o m e v a r i a t i o n a c c o r d i n g t o t h e t h e c l i n i c a l s e t t i n g a n d m e t h o d o f a n a l y s i s . G a r z o n e t a l .( 4 ) o b s e r v e d t h a t 4 9 .1 % o f 4 7 9 c h a g a s i c p a t i e n t s h a d ; a p i c a l a k i n e s i a o r d y s k i n e s i a , w i t h t h i s d i s t r i b u t i o n : i n
3 1 .6 % o f t h e i n d e t e r m i n a t e f o r m , i n 4 3 .1 % o f p a t i e n t s w i t h a b n o r m a l e l e c t r o c a r d i o g r a m , i n 6 3 .9 % o f p a t i e n t s w i t h
a b n o r m a l e l e c t r o c a r d i o g r a m a n d m o d e r a t e i n c r e a s e o f c a r d i a c s i z e a n d i n 6 2 .5 % o f p a t i e n t s w i t h e l e c t r o c a r d i o g r a p h i c a b n o r m a l i t i e s a n d v e r y d i l a t e d h e a r t s .
C o n t r a c t i o n a b n o r m a l i t i e s w e r e a l s o o b s e r v e d i n o t h e r r e g i o n s b u t i n s m a l l n u m b e r . I n o n e s t u d y , u s i n g w a l l
m o t i o n a n a l y s i s o f t h e l e f t v e n t r i c l e ( 2 1 ) . A p i c a l a k i n e s i a / d y s k i n e s i a w a s f o u n d i n 8 0 % o f c a s e s w i t h t h i s d i s t r i b u t i o n : i n 5 0 % o f c a s e s w i t h n o r m a l e j e c t i o n f r a c t i o n ( E F ) , i n
8 0 % o f c a s e s w i t h r e d u c e d E F b u t a b o v e 5 0 % , a n d i n 1 0 0 %
o f p a t i e n t s w i t h E F b e l o w 5 0 % .
G e n e r a l l y , t h e s e a r e s m a l l a b n o r m a l i t i e s ; i n o u r m a t e r i a l 6 w e n o t e l e f t v e n t r i c u l a r v o l u m e s s m a l l e r t h a n 5
m l / m2 i n 7 5 % o f c a s e s a n d t h e r e w a s n o c o r r e l a t i o n b e t w e e n v e n t r i c u l a r v o l u m e a n d E F .
T h e s e c o n t r a c t i o n a b n o r m a l i t i e s a s s u m e s e v e r a l
f o r m s d e s c r i b e d a s " n i p p l e " , " g l o v e 's f i n g e r " , " t e n n i s r a c q u e t " , e t c . I n p a t i e n t s w i t h E F a b o v e 5 0 % , t h e t r a n s i t i o n b e t w e e n t h e a p i c a l s e g m e n t a n d t h e b o d y o f t h e v e n t r i c l e
i s w e l l d e l i m i t e d s i n c e s e g m e n t a l s h o r t e n i n g f r o m b a s e t o a p e x i s u n i f o r m ( 2 1 ) . T h e s e n e c k l i k e i m a g e s c o r r e s p o n d c l e a r l y t o t h e a p i c a l l e s i o n o f C h a g a s ' h e a r t d i s e a s e , c h a r a c t e r i s t i c a l l y t h i n n e d a n d w e l l d e l i m i t ~ d f r o m t h e b o d y o f t h e c h a m b e r w h e n s e e n i n n e c r o p s y ( F i g u r e 1 a , b , c ) . O n t h e o t h e r h a n d , w h e n E F i s v e r y d e p r e s s e d , s e g m e n t a l
a
c
d
a
b
F ig u re 1 . Illu s tra tio n o f v e n tric u lo g ra p h ic s ilh o u e tte s in d ia s to le a n d s y s to le d e p ic tin g th e tra n s itio n z o n e b e tw e e n th e a p ic a l
a k in e tic /d is k in e tic s e g m e n t a n d th e v e n tric u la r b o d y . A rro w s in d ic a te n o tc h s o b s e rv e d e v e n in d ia s to le .
sh o rte n in g
fro m
b a se
to a p e x
is p ro g re ssiv e ly
d e c re a se d
u n til
z e ro
(a k in e sia )
w ith o u t
a d e m a rc a to ry
z o n e
a s a
tra n sitio n
(F ig u re
2
b ). T h is
ra ise s
th e q u e stio n
w h e th e r
th e se a p ic a l a k in e sia s
c o rre sp o n d
o r n o t to th e a p ic a l le sio n
o f
C h a g a s'
h e a rt
d ise a se .
W a ll
m o tio n
a n a ly sis
o f
c in e v e n tric u lo g ra m s,
a s d e p ic te d
in fig u re 1 d , d e m o n stra te
th a t
2 d iffe re n t
p ro c e sse ss
c a n
le a d
to a p ic a l
a k in e sia /
d y sk in e sia :
in
th is
silh o u e tte
th e
a p ic a l
se g m e n t
is
d isk in e tic
a n d is d iv id e d
in 2 p a rts
b y n o tc h s
o b se rv e d
e v e n in d ia sto le ;
th e m o re d ista l p o rtio n
sh o u ld c o rre sp o n d
to th e a p ic a l
le sio n
o f C h a g a s'
h e a rt d ise a se
b u t th e o th e r
p a rt, still p a rt o f th e a p ic a l sh e ll a n d a lso d isk in e tic ,
sh o u ld
b e c o n se q u e n c e
o f v e n tric u la r
d ila ta tio n
th a t, in c re a sin g
th e a n g le o f th e a p ic a l sh e ll, sh o u ld tu rn its n o rm a lly
h e lix
sh a p e d
fib e rs
m o re c irc u la r
(2 3 ).
It sh o u ld
b e sa id th a t a p ic a l
a k in e sia /d y sk in e sia
a re
a lso
fo u n d
in d ila te d
a n d
h y p o k in e tic
v e n tric le s
w ith
d ila te d
c a rd io m y o p a th y
(3 0 ), a n d its d iffe re n tia tio n
fro m
C h a g a s'
h e a rt d ise a se
c a n b e u n fe a sib le
if b a se d
o n ly o n
a n g io g ra p h ic
fe a tu re s.
T h is
p o in t
c a n
b e illu stra te d
in
F ig u re
2 w h e re
c in e v e n tric u lo g ra m s
o f a p a tie n t
w ith
d ila te d
c a rd io m y o p a th y
a n d a n o th e r
w ith
C h a g a s'
h e a rt
d ise a se
a re d e p ic te d :
in b o th th e re a re d iffu se h y p o k in e sia
a n d a p ic a l
a k in e sia .
Bidimensional Echocardiography
T h is
m e th o d
c a n
id e n tify
th e
a p ic a l
le sio n
n o n
-in v a siv e ly
a n d
p la y s
a n im p o rta n t
ro le
in th e
stu d y
o f
a sy m p to m a tic
p a tie n ts
w ith
th e
in a p a re n t
fo rm .
It is
im p o rta n t
in th e
fo llo w
u p o f a ll fo rm s
o f th e
d ise a se
(1 ,1 5 ,2 5 ).
Its se n sib ility
to d e te c t
th e a p ic a l
le sio n
is in
th e o rd e r o f 8 0 % (1 5 ). D ia g n o stic
im a g e s c a n b e o b ta in e d
in lo n g a x is v ie w , in a p ic a l fo u r-c h a m b e r
a n d tw o -c h a m b e r
v ie w s
a n d in su b c o sta l
v ie w , th e la tte r
a p p e a rin g
a s th e
m o re se n sitiv e .
C h a g a sic
a p ic a l le sio n is w e ll re c o g n iz e d
b y its w a ll
th in n in g
a n d a b n o rm a l
m o tio n ,
m a k in g
e v id e n t th e a b ru p t
tra n sitio n
w ith th e v e n tric u la r
b o d y . T h is a sp e c t is c le a rly
d iffe re n t
fro m
isc h e m ic
a n e u ry sm s.
W h e n
th e re
is
d ila ta tio n
a n d d iffu se
h y p o k in e sia
th is p a tte rn
m a y n o t b e
re c o g n iz e d
a n d
th e
im a g e
c a n
b e u n d istin g u ish e d
fro m
d ila te d
c a rd io m y o p a th y .
O n th e o th e r
h a n d ,
v e ry
sm a ll
le sio n c a n g o u n re c o g n iz e d .
It h a s b e e n d e m o n stra te d
th a t th e a p ic a l le sio n o c c u rs
in a ll c lin ic a l
fo rm s
(1 ,2 5 ),
a p p e a rin g
in 2 5 % o f c a se s o f
th e
in a p a re n t
fo rm .
R ig h t
v e n tric u la r
a p ic a l
le sio n
is
so m e tim e s
a lso
o b se rv e d .
A p ic a l
th ro m b i
a re o b se rv e d
m o re fre q u e n tly
in c a se s
w ith c o n g e stiv e
h e a rt fa ilu re .
Electrocardiogram
E le tro c a rd io g ra p h ic
a b n o rm a litie s
a re n o t a sso c ia te d
to a n sp e c ific
p a tte rn .
A c c o rd in g
to G a rz o n
e t a l. (9 ),
p a tie n ts
c a n
h a v e
p re m a tu re
v e n tric u la r
c o n tra c tio n s
(6 0 % ),
le ft
a n te rio r
h e m ib lo c k
(4 7 .5 % ),
rig h t
b u n d le
b ra n c h
b lo c k
(3 7 .4 % ),
Q -w a v e
p a tte rn
(2 3 % )
a n d
re p o la riz a tio n
a b n o rm a litie s
(2 6 .4 % ).
Nuclear Cardiology
In a g ro u p o f 2 3 p a tie n ts
w ith c h ro n ic
C h a g a s'
h e a rt
d ise a se
w ith
a ty p ic a l
c h e st
p a in ,
M a rin
N e to
e t a l. (1 6 )
stu d ie d ta lliu m -2 0 1
m y o c a rd ia l
sc in tig ra p h y
a fte r m a x im a l
e ffo rt,
c o n tra ste d
c in e v e n tric u lo g ra p h y
a n d
c o ro n a ry
a rte rio g ra p h y .
A ll p a tie n ts
h a d
a t le a st
o n e
se g m e n ta l
p e rfu sio n
d e fe c t, th a t w a s p e rm a n e n t
in 6 5 % a n d tra n sito ry
in 3 5 %
o f th e c a se s. P e rm a n e n t
d e fe c ts
p re d o m in a te d
in
a p ic a l
se g m e n ts
(8 8 % )
in
a g re e m e n t
w ith
c in e v e n tric u lo g ra p h y
a n d ra d io iso to p ic
v e n tric u lo g ra p h y .
F ix e d
d e fe c ts
w e re p re se n t
in 1 4 o f 2 3 p a tie n ts
(6 0 .8 7 % )
a n d
v e n tric u la r
a k in e sia /d y sk in e sia
in
1 1 o f
1 6 p a tie n ts
(6 8 % ).
T ra n sito ry
d e fe c ts
w e re
o b se rv e d
in n o rm a l
o r
h y p o k in e tic
se g m e n ts.
CLINICAL
SIGNIFICANCE
Ventricular function
T h e a p ic a l
a k in e tic /d isk in e tic
se g m e n ts
o f C h a g a s'
h e a rt
d ise a se
a re u su a lly
sm a ll
a n d
its v o lu m e s
d o n o t
c o rre la te
w ith v e n tric u la r
v o lu m e
o r w ith E F . T h u s, th e se
a b n o rm a litie s
d o n o t c o m p ro m ise
v e n tric u la r
fu n c tio n .
A p ic a l a k in e sia s/d y sk in e sia s
o c c u r g e n e ra lly
in v e n tric le s
a lre a d y
d ila te d
a n d h y p o k in e tic
a n d so a re p a rt o f g lo b a l
fu n c tio n a l
d e te rio ra tio n .
S o m e tim e s,
n o n e th e le ss,
th e re a re
c a se s
w ith
la rg e
a p ic a l
a b n o rm a litie s
w h o se
v e n tric le s
p re se n t
o n ly little o r m o d e ra te
d y sfu n c tio n
(F ig u re
Ie ). In
th is se ttin g ,
th e a p ic a l a b n o rm a litie s
a re re sp o n sib le
fo r a
c e rta in d e g re e o f m e c h a n ic a l
sy sto lic d y sfu n c tio n .
It sh o u ld
b e n o te d th a t w h e n d y sk in e sia
is p re se n t
it d o e s n o t h a v e a
tru e sy sto lic e x p a n sio n ,
lik e in a c u te m y o c a rd ia l
in fa rc tio n ,
b u t a m o v e m e n t
o f tra n sla tio n
o f th e w h o le
c h a m b e r
in
lo n g itu d in a l
d ire c tio n
(2 2 ).
Thromboembolism
L o c a l th r o m b u s f o r m a tio n is n o t r a r e a n d its
f r e q u e n c y d e p e n d s o n v e n tr ic u la r d y s f u n c tio n . W h e n th e r e
is v e n tr ic u la r d ila ta tio n a n d c o n g e s tiv e h e a r t f a ilu r e a p ic a l
th r o m b i c a n b e f o u n d in 5 0 % o f c a s e s ( 4 ) a n d e m b o lis m is
c o m m o n . I n le s s s e r io u s c lin ic a l p r e s e n ta tio n s e m b o lis m
is le s s f r e q u e n t b u t it c a n b e th e f ir s t m a n if e s ta tio n o f th e
d is e a s e . C lin ic a l m a n a g e m e n t in c lu d e a n tic o a g u la tio n a n d
e v e n a n e u r y s m e c to m y .
Arrhythmias
C o m p le x v e n tr ic u la r a r r h y th m ia s a r e c o m m o n in
C h a g a s ' h e a r t d is e a s e a n d c a n b e r e la te d to v e n tr ic u la r
d y s f u n c tio n o r a p ic a l le s io n ; a s th e s e tw o s itu a tio n s c a n
c o e x is t, c a s e s w ith s u s ta in e d v e n tr ic u la r ta c h y c a r d ia
d if f ic u lt to m a n a g e w ith d r u g s n e e d a p r e c is e d e f in itio n o f
th e a r r h y th m o g e n ic s ite . E le c tr o p h y s io lo g ic a l s tu d ie s h a s
d e m o n s tr a te d th a t a r r h y th m ia s c a n b e in d u c e d a n d te r m in a te d b y p r o g r a m m e d s tim u li ( 1 7 ,1 9 ) , s u g g e s tin g a
r e e n tr y m e c h a n is m . I n s e le c te d c a s e s a n e u r y s m e c to m y h a s b e e n p e r f o r m e d w ith g o o d r e s u lts ; e le c tr o p h y s io lo g ic a l
m a p p in g d u r in g s u r g e r y h a s im p lic a te d th e r e g io n s
a d ja c e n t to th e a n e u r y s m a s th e s o u r c e o f a r r h y th m ia .
PATHOGENESIS
B e c a u s e th e r e is n o a g r e e m e n t o n th e c a u s e o f th is
s o p e c u lia r le s io n o f C h a g a s ' h e a r t d is e a s e m a n y
h y p o th e s is h a d b e e n f o r m u la te d . A ll ta k e in to a c c o u n t th e
a n a to m ic s in g u la r itie s o f th e le f t v e n tr ic u la r v o r te x , a
r e g io n n o r m a lly v e r y th in .
Autonomic
imbalance
A c c o r d in g to K o b e r le ( 1 4 ) , th e c a r d ia c
p a r a s y m p a th e tic d e p o p u la tio n o f C h a g a s ' d is e a s e w o u ld
le a d to a r e la tiv e s y m p a th e tic h y p e r a c tiv ity , p o te n t e n o u g h
to c a u s e m y o c a r d ia l le s io n s . E x p e r im e n ta lly , a p ic a l a n e u r y s m s c a n b e p r o d u c e d in r a ts in je c tin g b e ta
-s y m p a th o m im e tic d r u g s , a n d th e y lo o k v e r y s im ila r to
c h a g a s ic a n e u r y s m s . H o w e v e r , a n a ly s is o f v e n tr ic u lo g r a m s o f 1 6 s y m p to m a tic p a tie n ts d id n o t d is c lo s e a r e la tio n
b e tw e e n c h a g a s ic a n e u r y s m s a n d p a r a s y m p a th e tic
d e p r e s s io n , o b s e r v e d w ith p h a r m a c o lo g ic a l b lo c k in g
a g e n ts ( 1 1 ) .
Mechanical factor
B y c a r e f u l a n a to m ic d is s e c tio n s , R a s o ( 2 8 ) n o te d a
s e p a r a tio n o f th e v o r tic a l f ib e r s a n d p r o tr u s io n o f th e
e n d o c a r d ia l a n d e p ic a r d ia l la y e r s , a s itu a tio n r e s e m b lin g
a h e r n ia . T h e n , o v e r th is m y o c a r d ia l w e a k s p o t, s y s to lic
p r e s s u r e w o u ld a c t a s a e x p a n d in g f o r c e , s tr e tc h in g o u t
th e v o r tic a l f ib e r s a n d p r o d u c in g th e a n e u r y s m .
Conduction disturbances
B a s e d o n a n o b s e r v a tio n o f a s ta tis tic a l c o r r e la tio n
b e tw e e n th e p r e s e n c e o f a p ic a l le s io n a n d le f t a n te r io r
h e m ib lo c k , C a r v a lh a l ( 5 ,6 ) p o s tu la te d a c a u s a l r e la tio n s h ip .
L o c a l d e la y o f p e r ia p ic a l c o n tr a c tio n w o u ld a ls o p u t f o r th
s y s to lic e x p a n s io n o f th e a p e x , le a d in g to a p ic a l a n e u r y s m
f o r m a tio n . T h is c o r r e la tio n w a s n o t f o u n d b y o th e r s ( 2 )
b u t th is m e c h a n is m w o u ld s till b e im p lic a te d if o n e
c o n s id e r s lo c a l c o n d u c tio n d is tu r b a n c e s in th e s a m e w a y
f o u n d b y A n s e lm i e t a l. ( 3 ) w ith e p ic a r d ia l
e le c tr o c a r d io g r a m s ta k e n o v e r a p ic a l a n e u r y s m s o f c a n in e
h e a r t w ith e x p e r im e n ta l C h a g a s ' h e a r t d is e a s e . I n o n e s tu d y
f o c u s in g th e s e q u e n c e o f s e g m e n ta l c o n tr a c tio n o f th e le f t
v e n tr ic le o f c h a g a s ic p a tie n ts , w ith a n d w ith o u t le f t a n te r io r
h e m ib lo c k , w e d id n o t o b s e r v e a d e la y o f a p ic a l s e g m e n t
c o n tr a c tio n ( 2 2 ) .
Myocarditis
S e v e r a l in v e s tig a to r s ( 1 8 ,2 7 ,2 8 ) e s ta b lis h e d
c o n c e p tio n s th a t u ltim a te ly w o u ld im p lic a te a c u te a n d
c h r o n ic m y o c a r d itis p lu s th e m e c h a n ic a l f a c to r ( s y s to lic
p r e s s u r e ) : th in n in g o f th e a p e x w o u ld b e p r o d u c e d b y
in f la m m a to r y le s io n s o f th e in te r n a l la y e r o f th e v o r te x ,
w ith d is a r r a y o f its s p e c ia l a r c h ite c tu r e a n d p r o g r e s s iv e
s e p a r a tio n o f th e m u s c le f ib e r s , s u b m itte d to
in tr a v e n tr ic u la r p r e s s u r e s .
The role played by acute myocarditis
A lth o u g h d iv is io n o f c h a g a s ic p a tie n ts in c lin ic a l
f o r m s is s o m e w h a t a r tif ic ia l, it m a k e e v id e n t th e la r g e
s p e c tr u m o f a b n o r m a litie s , f r o m a lm o s t n o r m a l h e a r ts u p
to th o s e w ith a ll ty p e s o f a lte r a tio n s . T h e a p ic a l le s io n o c c u r s in a ll f o r m s o f th e d is e a s e a n d its p r e s e n c e a n d s iz e
d o n o t c o r r e la te w ith a g e , s iz e o f th e h e a r t, g lo b a l c a r d ia c
f u n c tio n , e le c tr o c a r d io g r a p h ic a b n o r m a litie s o r a u to n o m ic im b a la n c e . I t is , th u s , in d e p e n d e n t o f th e n a tu r a l p r o c e s s
o f th e d is e a s e a n d it s e e m s r e a s o n a b le to b e lin k e d to th e
w o u ld
d o m o re h arm
in th e m o re frag ile
seg m en ts
o f th e
h eart, n am ely th e ap ical reg io n , allo w in g sy sto lic p ressu res
to stretch
o u t
th e
p eriv o rtical
m u scle
b u n d les
an d
to
an eu ry sm
fo rm atio n .
O b v io u sly ,
an eu ry sm s
w o u ld
b e
ev id en t
o n ly in p atien ts
w h o su rv iv e th e acu te p h ase. T h is
reaso n in g
im p lies
th at a sim ilar
lesio n
sh o u ld
also h av e
b een
o b serv ed
in o th er
acu te
m y o card itid is,
an id ea n o t
sh ared
b y th e m ajo rity
o f in v estig ato rs.
H o w ev er,
in o u r
o p in io n ,
so m e
reaso n in g
w o u ld
h elp ex p lain
w h y ap ical
lesio n s
are n o t fo u n d
in o th er ty p es
o f m y o card itis
w ith
th e freq u en cy
an d ex u b eran ce
o f C h ag as'
h eart d isease.
T h ere
are rep o rts
o f lo cal co n tractio n
ab n o rm alities
in acu te
v iral m y o card itis
(1 0 ,2 6 ,2 9 ).
A lso , it is p o ssib le
to p ro d u ce ex p erim en tally
v en tricu lar
an eu ry sm s
w ith v iral
in fectio n s
(7 ).
P rev alen ce
o f o th er acu te
m y o card itis,
lik e v iral, is
lesser th an in C h ag as'
h eart d isease. F o r in stan ce, in 5 ,7 1 5
n ecro p sies
p erfo rm ed
in th e D ep artm en t
o f P ath o lo g y
o f
R ib eirao
P reto , b etw een
1 9 5 4 an d 1 9 6 8 , 2 0 % h ad C h ag as'
d isease (2 4 ).
In
o n e Jap an ese
series, o f 3 7 7 ,8 4 1 n ecro p sies
o n ly
0 .1 % h ad v iral o r in esp ecific
m y o card itis
(3 1 ). B y
th e
sam e
to k en ,
b io lo g ical
v ariab ility
sh o u ld
b e m u ch
g reater
in C h ag as'
h eart d isease.
C h ag asic
p atien ts
are easily
id en tified
b y sp ecific
sero lo g ic
reactio n
an y
tim e
in th eir
ev o lu tio n .
O n th e
co n trary ,
it is d ifficu lt
to estab lish
a sp ecific
etio lo g ic
d iag n o sis
o f acu te
v iral m y o card itis.
E v en
m o re d ifficu lt
it is to estab lish
w h at
in d iv id u als
h ad
an
acu te
v iral
m y o card itis
in th e p ast.
T h at
is reaso n
w h y
it h as b een
d ifficu lt
to p ro v e
a cau sal
relatio n sh ip
b etw een
v iral
m y o card itis
an d d ilated
card io m y o p ath y .
In
co u n tries
w h ere
C h ag as'
d isease
is en d em ic
th e
ap ical lesio n
is activ ely
so u g h t,
in clin ical
in v estig atio n s
o r at th e n ecro p sy
tab le, b ecau se
it rep resen ts
a d iag n o stic
asp ect o f a co m m o n
d isease. T h erefo re,
a v ery sm all ap ical
an eu ry sm
can b e o n ly
fo u n d
at n ecro p sy
if a sectio n
is
m ad e th ro u g h
th e left v en tricu lar
v o rtex .
T h is
is n o t th e
p ractice
in o th er
co u n tries,
w h ere
m y o card itis
are
n o t
co m m o n .
W h eth er
v iral (o r o th er) m y o card itis
p ro d u ce
o r
n o t a left v en tricu lar
ap ical
lesio n
is, in o u r o p in io n ,
still
an o p en q u estio n .
A s th e acu te p h ase
o f C h ag as',
h eart d isease
o ccu rs
in ch ild ren ,
w e b eliev e th at th is sp ecial circu m stan ce
co u ld
b e
fav o rab le
fo r
ap ical
lesio n
fo rm atio n .
In fan tile
m y o card ial
tissu e
h as m u ch
less elastic
rig id ity
b ecau se
o f its sm aller
fib ers
an d less co llag en
co n ten t,
an d so th e
v en tricu lar
w alls
are
less
resistan t
to
d y sk in esia,
p articu larly
th e
ap ex
an d
su b an n u lar
reg io n s.
In
so m e
rep o rts th is p o in t is m ad e ev id en t: ex p erim en tal
p ro d u ctio n
o f v en tricu lar
an eu ry sm s
in m ice
w ith
C o x sack ie
v iru s
in fectio n
w as o n ly p o ssib le
in th e su ck lin g
an im als
(7 ).
In
an o th er
stu d y ,
K elly
et al. (1 3 )
w ere
ab le
to p ro d u ce
v en tricu lar
an eu ry sm s
in su ck lin g
rats b y p h arm aco lo g ical
in h ib itio n
o f elastic
an d co llag en
fib ers
d ev elo p m en t.
REFERENCES
1 . A C Q U A T E L L A , H .; S C H IL L E R , N .B .; P U IG B O , J.1 . e t a l. - M -M o d e a n d tw o -d im e n sio n a l e c h o c a rd io g ra p h y in c h ro n ic C h a g a s' h e a rt d ise a se . A c lin ic a l a n d p a th o lo g ic stu d y . C irc u la tio n 6 2 :7 8 7 -7 9 9 , 1 9 8 0 .
2 . A L M E ID A , H .O .; M IZ IA R A , L .J.; P R A N G E , P .1 . e t a l. -H e m ib lo q u e io a n te rio r e sq u e rd o e le sa o v o rtic ila r e sq u e rd a n a c a rd io p a tia c h a g a sic a c ro n ic a . A rq B ra s C a rd io I2 8 :2 9 3 -2 9 7 ,1 9 7 5 .
3 . A N S E L M I, A .; P IF A N O , E ; S U A R E Z , J.A . e t a l. - M y o c a r-d io p a th y in C h a g a s' d ise a se . A m H e a rt J 7 2 :4 6 9 -4 8 1 , 1 9 6 6 . 4 . A R T E A G A -F E R N A N D E S , E .; B A R R E T O , A .C .P .; IA N N I,
B .M . e t a l. - T ro m b o se c a rd fa c a e e m b o lia e m p a c ie n te s fa le c id o s d e c a rd io p a tia c h a g a sic a c ro n ic a . A rq B ra s C a rd io l 5 2 : 1 8 9 -1 9 2 , 1 9 8 9 .
5 . C A R V A L H A L , S .S . - A le sa o a p ic a l n a c a rd io p a tia c h a g a sic a . A rq B ra s C a rd io I2 5 :2 5 7 -2 6 2 , 1 9 7 2 .
6 . C A R V A L H A L , S .S .; N O G U E IR A , E .A .; C U R T I, H .V . e t a l. - A le sa o a p ic a l n a c a rd io p a tia c h a g a sic a . M e m In st
0
C ru z , A n a is d o C o n g re sso In te rn a c io n a l so b re D o e m ;a d e C h a g a s 1 9 7 9 ; G13-G
1 77 . E L -K H A T IB , M .R .; C H A S O N S , 1 .L .
&
L E R N E R , A .M . -V e n tric u la r a n e u ry sm s c o m p lic a tin g C o x sa c k ie v iru s G ro u p B , T y p e s 1 a n d 4 m u rin e m y o c a rd itis. C irc u la tio n 5 9 :4 1 2 -4 1 6 ,1 9 7 9 .
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9 . G A R Z O N , S .A .C .; L O R G A , A .M .; JA C O B , J.L .B . e t a l. -A c in e a n g io g ra fia d o v e n trfc u lo e sq u e rd o n a d o e n c ;a d e C h a g a s c ro n ic a . P a rte III: A p re c ia c ;a o m o rfo l6 g ic a e a sp e c to s c lfn ic o s e e v o lu tiv o s d a a ssin e rg ia a p ic a l d o V .E . M e m In st o C ru z , A n a is d o C o n g re sso In te rn a c io n a l so b re D o e n ~ a d e C h a g a s 1 9 7 9 ; 1 0 6 .
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1 1 . G R A N Z O T T I, J .A . - C o n trib u i~ a o a o e stu d o d o "a n e u rism a " d a p o n ta n a c a rd io p a tia c h a g a sic a c ro n ic a .
1 9 7 3 [T e se - F a c u ld a d e d e M e d ic in a d e R ib e id io P re to , U S P ]. 1 2 . JO R G E , P .A .R . - Im p o rta n c ia d a a re a d e a c in e sia a p ic a l n a c o n tra tilid a d e d o c o ra c ;a o c h a g a sic o c ro n ic o . P e rsp e c tiv a c iru rg ic a . A rq B ra s C a rd io l 2 4 :3 1 -3 5 , 1 9 7 1 .
1 3 . K E L L Y , W .A .; K E S T E R S O N , J.W .
&
C A R L T O N , W .W . -M y o c a rd ia l le sio n s in th e o ffsp rin g o f fe m a le s ra ts fe d a c o p p e r d e fic ie n t d ie t. E x p M o le c P a th o I2 0 :4 0 -5 6 , 1 9 7 4 . 1 4 . K O B E R L E , F . - C a rd io p a tia c h a g a sic a . H o sp ita l 5 3 :9 -5 0 ,1 9 5 8 .
1 5 . L O P E S , N .M .P .; F IL H O , J.M .; A L B A N E S I, E E M . e t a l. -C o rre la c ;a o e n tre o s a c h a d o s d a e c o c a rd io g ra fia b id im e n sio n a l e a c in e v e n tric u lo g ra fia e sq u e rd a n a le sa o a p ic a l d o v e n tric u lo e sq u e rd o n a c a rd io p a tia c h a g a sic a c ro n ic a . A rq B ra s C a rd io l 4 6 : 10 5 -1 1 3 , 1 9 8 6 .
1 6 . M A R IN -N E T O , J.A .; M A R Z U L L O , P .; M A R C A S S A ,
c.;
G A L L O JR , L .; M A C IE L , B .C .; B E L L IN A , R .&
L ' A B B A T E , A . - M y o c a rd ia l P e rfu sio n A b n o rm a litie s in C h ro n ic C h a g a s'D ise a se a s D e te c te d b y T h a lliu m -2 0 1 S c in tig ra p h y . A m J C a rd io l 6 9 :7 8 0 -7 8 4 , 1 9 9 2 .1 7 . M E N D O Z A , I.; JO S E P H ,
c.;
F E D E R IC O , M . e t a l. -S u sta in e d v e n tric u la r ta c h y c a rd ia in c h ro n ic c h a g a sic m y o c a rd itis: E le c tro p h y sio lo g ic a n d P h a rm a c o lo g ic c h a ra c te ristic s. A m J C a rd io l 5 7 :4 2 3 -4 2 7 , 1 9 8 6 . 1 8 . M IG N O N E , C . - A lg u n s a sp e c to s d a c a rd ite c h a g a sic ac ro n ic a . S a o P a u lo , 1 9 5 8 [T e se - F a c u ld a d e d e M e d ic in a d a U n iv e rsid a d e d e S a o P a u lo ].
1 9 . M IL E I, J.; P E S C E , R .; V A L E R O , E . e t a l. -E le c tro p h y sio lo g ic -stru c tu ra l c o rre la tio n s in c h a g a sic a n e u ry sm s c a u sin g m a lig n a n t a rrh y th m ia s. In t J C a rd io l 3 2 :6 5 -7 4 , 1 9 9 1 .
2 0 . N O G U E IR A , E .A . - A v a lia c ;a o d a c a v id a d e v e n tric u la r e sq u e rd a d e p a c ie n te s c o m c a rd io p a tia c h a g a sic a c ro n ic a p e la c in e v e n tric u lo g ra fia . 1 -T a m a n h o , fo rm a e m o v im e n ta c ;a o g lo b a l. A rq B ra s C a rd io l 5 0 :3 3 -4 2 , 1 9 8 8 .
2 1 . N O G U E IR A , E .A . - A v a lia c ;a o d a c a v id a d e v e n tric u la r e sq u e rd a d e p a c ie n te s c o m c a rd io p a tia c h a g a sic a c ro n ic a p e la c in e v e n tric u lo g ra fia .
IT -
M o v im e n ta c ;a o se g m e n ta r e n tre d ia sto le fin a l e sfsto le fin a l. A rq B ra s C a rd io I5 0 :3 6 9 -3 7 6 , 1 9 8 8 . 2 2 . N O G U E IR A , E .A . - A v a lia c ;a o d a c a v id a d e v e n tric u la re sq u e rd a d e p a c ie n te s c o m c a rd io p a tia c h a g a sic a c ro n ic a p e la c in e v e n tric u lo g ra fia . III- M o v im e n ta c ;a o se g m e n ta r d u ra n te o p e rfo d o sist6 lic o . A rq B ra s C a rd io I5 1 :1 3 5 -1 4 1 , 1 9 8 8 . 2 3 . N O G U E IR A , E .A .; C A R V A L H A L , S .S .; M C M IL L A N , R .M .
& M A R A N H A o , V . - A n a ly sis o f th e p o sitio n o f th e b a se a n d a p e x o f th e le ft v e n tric le d u rin g sy sto le . C a th e t C a rd io v a sc D ia g n 1 3 :2 5 3 -2 6 1 , 1 9 8 7 .
2 4 . O L IV E IR A , J.S .M .; O L IV E IR A , J.A .M .; F R E D E R IG U E JR ., U . e t a l. - A p ic a l A n e u ry sm o f C h a g a 's h e a rt d ise a se . B r H e a rt J 4 6 :4 3 2 -4 3 7 , 1 9 8 1 .
2 5 . O R T IZ , 1 .; B A R R E T O , A .C .P .; M A T S U M O T O , A .Y . e t a l. -A lte ra c a o c o n tra til se g m e n ta r n a fo rm a in d e te rm in a d a d a d o e n c ;a d e C h a g a s. E stu d o e c o c a rd io g ra fic o . A rq B ra s C a rd io I4 9 :2 1 7 -2 2 0 , 1 9 8 7 .
2 6 . P IN A M O N T I, B .; A L B E R T I, E .; C IG A L O T T O , A . e t a l.-E c h o c a rd io g ra p h ic fin d in g s in M y o c a rd itis. A m J C a rd io l 6 2 :2 8 5 -2 9 1 , 1 9 8 8 .
2 7 . P U P O JR ., A .P . - C o n trib u i~ a o a o e stu d o d a p a to g e n ia d a le sa o fib ro tic a a p ic a l n o c o ra ~ a o d e c h a g a sic o s c ro n ic o s. S a o P a u lo , 1 9 6 9 [T e se - E sc o la P a u lista d e M e d ic in a ]. 2 8 . R A S O , P . - C o n trib u i~ a o a o e stu d o d a le sa o v o rtic ila r
(e sp e c ia lm e n te d o v o rtic e e sq u e rd o ) n a c a rd ite c h a g a sic a c ro n ic a . 1 9 6 4 [T e se - F a c u ld a d e d e M e d ic in a d a U n iv e rsid a d e d e M in a s G e ra is].
2 9 . S A T O , Y .; O S A K U , A .; K O Y A M A , S . e t a l. - C o m p le te a trio v e n tric u la r b lo c k a sso c ia te d w ith re g io n a l m y o c a rd ia l sc a rrin g in a p a tie n t w ith c o x sa c k ie B 2 m y o c a rd itis. Jp n H e a rt J 3 0 :9 3 5 -9 4 1 , 1 9 8 9 .
3 0 . T E R Z IS , M .A .H . - A n a lise d a m o v im e n ta c ;a o se g m e n ta r d o v e n trfc u lo e sq u e rd o e m p a c ie n te s c o m m io c a rd io p a tia d ila ta d a , p e la c in e v e n tric u lo g ra fia . N o p re lo .
