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Atypical Presentation of Acute 129
Coronary Syndrome in Diabetics

patients with atypical presentation had less coronary Dobutamine stress echocardiography : This is a use-
angiography and subsequent revascularisation, anti- ful diagnostic test for detecting SMI. In a study by
coagulant, antiplatelet and B-blocker therapy. Mbaye et.al, among 79 diabetics positive test was
seen in 67.1% with a predominance of wall motion
ATYPICAL PRESENTATION IN DIABETES . abnormalities in the anterior area (83%)
Why? SPECT Scan- DIAD study (Detection of Ischaemia in
Despite the fact that CAD is the primary vascular Asymptomatic Diabetics) identified SMI in 21 – 24%
complication of diabetes, there is a significant gap of intermediate and high cardiovascular risk patients.
in the knowledge and understanding on atypical ACS
symptom in diabetics. SILENT MYOCARDIAL ISCHAEMIA IN

Diabetics may have a diminished awareness of isch- DIABETICS – To screen or not ?
aemic chest pain which could result in an atypical Due to greater risk of cardiovascular events and
presentation . This can be explained by autonom- more frequent silent CAD in diabetics compared to
ic neuropathy and prolongation of the angina per- non-diabetics, screening asymptomatic diabetic pa-
ceptional threshold due to sensory denervation. A tients for CAD is an attractive concept. However there
change in Beta endorphin levels has also been pro- is paucity of confirmed data that a prospectively uti-
posed as a cause of atypical presentation. lized screening programme has a positive prognostic
impact in asymptomatic diabetic patients.
Cardiac autonomic neuropathy contributes for in-
creased risk of sudden death and also for silent Long standing diabetics; patients with diabetic com-
myocardial ischaemia. plication like neuropathy and nephropathy; diabetics
with two or more cardiovascular risk factors should
SILENT MYOCARDIAL ISCHAEMIA (SMI) undergo screening for SMI. A Stress ECG may be the
Diabetes is considered as an independent risk factor initial screening test. If the exercise ECG is non-di-
for the presence of SMI. Silent Myocardial Ischaemia agnostic or if the test is submaximal, a myocardial
is seen in 28.5% of diabetics . Upto 25% of patients perfusion scan may be recommended. A Dobuta-
with CAD have suffered silent SMI. The magnitude mine stress echocardiography may also be used as
of the myocardium involved is on an average 10% of it is comparable to scintigraphy. If a large ischaemia
left ventricle muscle mass. Cardiac autonomic neu- involving more than 20 – 25% of the myocardium is
ropathy is considered as the risk factor for SMI in detected a coronary angiogram is justified.
diabetics.

HOW TO ASSESS SILENT MYOCARDIAL
ISCHAEMIA (SMI) ?
The Primary step is to identify diabetic individuals at
high risk for SMI.
Patients with advanced age, hypertension, low HDL
and hypertriglyceridemia are considered as high risk
individuals. A high carotid intima medial thickness
also points for high risk of CAD in non-insulin de-
pendent diabetic patients even in those without ev-
ident CAD.
The presence of higher microalbuminuria also inden-
tifies patients with SMI.
Erectile dysfunction may become a possible indicator
to identify diabetic patients with SMI during screen-
ing.

TESTS USED TO EVALUATE SMI:
Exercise stress test; A Positive test for silent isch-
aemia is seen in about 19% of diabetics.

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