Information for the General Public
Normally
when
blood
supply
to
a
portion
of
the
heart
muscle
is
inadequate
(ischaemia)
you
will
suffer
from
angina
characterised by one of the following -
•
acute chest pain,
•
feeling tight in your chest or
•
pain radiating to your left arm, shoulder or neck.
If
the
blood
supply
is
cut
off
completely
you
will
suffer
a
heart
attack.
These
symptoms
are well known to most of us and we will seek urgent medical help if it occurs.
However,
there
are
many
in
the
world
who
suffer
from
ischemic
episodes
without
realising
it
as
they
do
not
have
symptoms
normally
attributed
to
angina.
This
is
known
as
silent
ischaemia.
They
may
also
suffer
a
heart
attack
with
no
warning.
People
who
have
had
previous
heart
attacks
or
those
with
diabetes
are
especially
at
risk
of
developing
silent
ischemia.
It
is
said
that
"silent"
(asymptomatic)
myocardial
ischemia
is
the
most
common
manifestation
of
coronary
heart
disease
(CHD),
accounting
for
more
than 75 percent of ischemic episodes during life.
Painless
myocardial
infarctions
on
the
other
hand
vary
a
little
from
silent
ischaemia
or
infarction.
Although
there
may
not
be
chest
pain
or
radiating
pain
in
painless
myocardial
infraction,
other
symptoms
relating
to
the
condition
may
be
present.
They
are:
•
Profuse sweating
•
Palpitation (due to increased sympathetic activity)
•
Breathlessness (due to cardiac failure)
•
Feel faint (syncope due to hypotension)
•
Extreme fatigue (due to poor tissue perfusion)
•
Sometimes patients become unconscious because of severe cerebral hypoperfusion (not enough blood reaching the
brain).
Both
silent
ischaemia
and
painless
ischaemia
occur
in
poorly
controlled
diabetics
and
non-diabetics
over
the
age
of
seventy.
The
reason
is
because
the
pain
conducting
nerve
fibres
are
paralysed
in
diabetes
and
old
age
and
hence
you
do
not
feel
the
pain.
If
any
of
the
symptoms
described
above
is
seen,
it
is
essential
to
have
your
heart
checked
urgently.
Diabetics
must
be
particularly warned about this.
Investigations:
•
Urgent ECG will normally show changes relating to ischaemia or infarction.
•
Blood Test to check cardiac enzymes and proteins should be done even when the ECG appears normal.
The
blood
test
will
measure
the
levels
of
enzymes
and
proteins
that
are
linked
with
injury
of
the
heart
muscle.
They
include
the
enzyme
creatine
kinase
(CK),
and
the
proteins
troponin
I
(TnI)
and
troponin
T
(TnT).
Their
levels
will
rise
if
the
heart
has
suffered an injury.
If the ECG and blood tests are inconclusive two further tests could be done to make sure your heart is healthy.
Ambulatory Electrocardiogram:
•
I
f
your
doctor
is
able
to
arrange
this,
a
small
recorder
will
be
attached
by
a
belt
to
your
waist.
The
machine
will
be
connected
by
wires
to
your
chest.
It
will
continuously
record
the
electrical
activity
of
your
heart
as
you
carry
on
with
your
normal
activities
over
a
period
of
24
to
48
hours.
If
your
heart
is
affected
during
this
period
your
doctor
will
be
able
to
pick
this
up
through
the recording on the machine.
Stress ECG
:
•
This
will
be
the
ultimate
test
to
check
if
your
heart
is
normal
and
healthy.
Here
you
will
be
connected
to
the
machine
by
a
few
leads.
The
ECG
is
then
recorded
while
you
are
on
a
treadmill.
The
stress
levels
of
your
heart
will
be
increased
slowly
by
making
you
walk
faster
and
if
necessary
with the treadmill at an upward incline.
•
This
test
should
only
be
done
with
a
cardiologist
nearby
as
he
will
know
when
to
stop
the
test
if
you
are
in
trouble
or
will
be
able
to
resuscitate
you
immediately if you suffer from a cardiac episode.
Complication
and
mortality
are
more
often
seen
in
painless
infarction
than
when
you
have
associated
chest
pain.
The
probable
cause
for
high
mortality
is
that
patients
normally
ignore
their
symptoms
when
they
have
no
chest
pain.
They
usually
continue
with
their
routine
activities,
if
symptoms
are
bearable.
Continued
activity
in
the
presence
of
myocardial
infraction
will
lead
to
complications like
irregular
heart
beat,
cardiac
failure
and
death.
This
is
very
common
in
India
compared
to
other
countries. It is estimated that more than 900 Indians under the age of 30 die from it everyday.
It
is
more
difficult
to
identify
someone
with
silent
ischemia
or
infarction
as
they
do
not
have
any
symptoms
recognised
as
originating
from
the
heart.
High
risk
populations
(diabetics
and
elderly)
should
be
made
aware
of
this
and
should
be
advised
on regular health checks and how they should protect their heart.
It
is
important
that
everyone
becomes
aware
of
this
silent
killer.
If
you
have
had
any
of
the
symptoms
mentioned
with
no
accompanied chest pain, do not assume that your heart is not the cause. Seek advice and have your heart checked.
Prof. S. Vaithinathan, MD., DM Cardiology.
Painless heart attack