The AHA Guidelines and Scientifi c Statements Handbook
should be initiated as soon as possible and is not
contingent on a bedside biomarker assay. (Level of
Evidence: C)
- Imaging
Class I
1 Patients with STEMI should have a portable chest
X-ray, but this should not delay implementation of
reperfusion therapy (unless a potential contraindi-
cation, such as aortic dissection, is suspected). (Level
of Evidence: C)
2 Imaging studies such as a high-quality portable
chest X-ray, transthoracic and/or transesophageal
echocardiography, and a contrast chest computed
tomographic scan or a MRI scan should be used to
differentiate STEMI from aortic dissection in
patients for whom this distinction is initially unclear.
(Level of Evidence: B)
Class IIa
Portable echocardiography is reasonable to clarify
the diagnosis of STEMI and allow risk stratifi cation
of patients with chest pain on arrival at the ED,
especially if the diagnosis of STEMI is confounded
by left bundle branch block (LBBB) or pacing, or
there is suspicion of posterior STEMI with anterior
ST depressions. (See Section 7.6.7 Mechanical
Causes of Heart Failure/Low Output Syndrome of
the full-text guidelines.) (Level of Evidence: B)
Class III
Single-photon emission computed tomography
(SPECT) radionuclide imaging should not be per-
formed to diagnose STEMI in patients for whom the
diagnosis of STEMI is evident on the ECG. (Level of
Evidence: B)
C. Management
- Routine measures
a. Oxygen
Class I
Supplemental oxygen should be administered to
patients with arterial oxygen desaturation (SaO 2 less
than 90%). (Level of Evidence: B)
Class IIa
It is reasonable to administer supplemental oxygen
to all patients with uncomplicated STEMI during
the fi rst 6 hours. (Level of Evidence: C)
b. Nitroglycerin
Class I
1 Patients with ongoing ischemic discomfort should
receive sublingual nitroglycerin (0.4 mg) every 5
minutes for a total of three doses, after which an
assessment should be made about the need for intra-
venous nitroglycerin. (Level of Evidence: C)
2 Intravenous nitroglycerin is indicated for relief of
ongoing ischemic discomfort, control of hyperten-
sion, or management of pulmonary congestion.
(Level of Evidence: C)Class III
1 Nitrates should not be administered to patients
with systolic blood pressure less than 90 mm Hg or
greater than or equal to 30 mm Hg below baseline,
severe bradycardia (less than 50 bpm), tachycardia
(more than 100 bpm), or suspected RV infarction.
(Level of Evidence: C)
2 Nitrates should not be administered to patients
who have received a phosphodiesterase inhibitor for
erectile dysfunction within the last 24 hours (48
hours for tadalafi l). (Level of Evidence: B)c. Analgesia
Class I
1 Morphine sulfate (2 to 4 mg IV with increments
of 2 to 8 mg IV repeated at 5- to 15-minute inter-
vals) is the analgesic of choice for management of
pain associated with STEMI. (Level of Evidence: C)
2 Patients routinely taking NSAIDs (except for
aspirin), both nonselective as well as COX-2 selective
agents, before STEMI should have those agents discon-
tinued at the time of presentation with STEMI because
of the increased risk of mortality, reinfarction, hyper-
tension, heart failure, and myocardial rupture associ-
ated with their use. (Level of Evidence: C)Class III
NSAIDs (except for aspirin), both nonselective as
well as COX-2 selective agents, should not be admin-
istered during hospitalization for STEMI because of
the increased risk of mortality, reinfarction, hyper-
tension, heart failure, and myocardial rupture asso-
ciated with their use. (Level of Evidence: C)d. Aspirin
Class I
Aspirin should be chewed by patients who have not
taken aspirin before presentation with STEMI. The