ACS and the 12 Lead
ECG
• The 12 Lead ECG is at the center of the
decision pathway in the management
of patients with ischemic chest pain.
AHA Guidelines 2000
Scenario #1
• 55 y/o male c/o sub-sternal chest pressure
that started while exerting himself. Pain
radiates to his neck/jaw. Pain unrelieved
with rest or patients own NTG.
• Patient is cool, and pale.
• DX?
Scenario #2
• 60 y/o female c/o dull, aching, pain in her chest
that radiates to her left breast. Sts pain has
been constant for past hour, getting increasingly
worse. Hx of HTN, NIDDM, Angina. Sts pain is
like previous angina attack, just worse.
• Patient is cool, pale, diaphoretic.
• DX?
• What similarities do these two scenarios
share?
• How can their treatment both be different.
• How will the 12 lead guide our treatment of
these patients?
Introduction
• Acute Coronary Syndrome is a group of
disease process’s that signs and
symptoms mimic each other.
• Although similar, they are not the same.
• The treatment for ACS is based on the
patient’s current “stage” in the disease
process
A
C
S
S
T
A
G
E
S
Stable Angina
• A flow/demand
imbalance between
reduced blood flow
through a narrowed
artery, and increased
demand.
Unstable Angina/Non-Q Wave
Infarction
• Symptoms of angina that are new or
increasing or that occur at rest. Seldom
relieved with rest, O2, or NTG.
• Symptoms are usually due to platelet
aggregation in narrowed arteries with
chronic atherosclerotic occlusions.
Unstable Angina/Non-Q Wave
Infarction
Unstable Angina can be complicated by the
release of micro-emboli that occlude distal
micro-vasculature.
Q-Wave Infarction
• Complete formation of
thrombus in an artery.
• Spontaneous lysis of
the clot can occur, but
often too late to
salvage the heart
muscle.
Indicative Changes
• Ischemia: Symmetrically inverted T waves
or down sloping ST segment depression
greater then 1mm
• Injury: ST segment elevation greater then
1mm
• Infarct: Pathological Q wave formation
Ischemia
Injury/Infarction
Indicative Changes
• Based on the patients 12 lead ECG, they
will be placed into 1 of 3 treatment
categories that are aimed at correcting the
specific Acute Coronary Syndrome
present.
Treatment Categories
Why Do We Care?
• The only ACS disease process that
benefits from Thrombolytic therapy are
those that are caused by complete
occlusion of an artery.
• Recognition of ST Segment Elevation ACS
is the first step in a race against the clock.
Treatment Strategies
Treatment Strategies
Treatment Strategies
Treatment Strategies
NO
YES
Scenario Review
Scenario #1
• 55 y/o male c/o sub-sternal chest pressure
that started while exerting himself. Pain
radiates to his neck/jaw. Pain unrelieved
with rest or patients own NTG.
• Patient is cool, and pale.
Scenario #1
• Does this patient meet ECG requirements
for thrombolysis?
• What stage of ACS can you predict from
the presenting 12 lead?
• What complications can you expect to see
if the patient’s condition worsens?
Scenario #2
• 60 y/o female c/o dull, aching, pain in her chest
that radiates to her left breast. Sts pain has
been constant for past hour, getting increasingly
worse. Hx of HTN, NIDDM, Angina. Sts pain is
like previous angina attack, just worse.
• Patient is cool, pale, diaphoretic.
Scenario #2
• Does this patient meet ECG requirements
for thrombolysis?
• What significance do the tall T waves
suggest?
• What complications can you expect to see
if the patient’s condition worsens?
Exceptions to the Rules
• Some subsets of patients may be eligible
for Fibrinolytic therapy even though they
do not present with ST segment elevation.
– Posterior current of injury
– Tall, hyperacute t waves