Page 170 - Clinical Pearls in Cardiology

158 Clinical Pearls in Cardiology

9. What are the indications for CABG in myocardial
infarction?
Coronary artery bypass grafting or CABG is considered
to have a better outcome than multivessel PCI in the
following subsets of patients:

Indications for CABG
• Those with severe angina and left ventricular dysfunction in
whom complete revascularization cannot be accomplished
by PCI.
• Those who have a large amount of myocardium at risk due to
significant left mainstem disease, diffuse triple vessel disease
or two vessel disease with significant involvement of the LAD
artery.

10. What are the contraindications for beta-blocker
therapy in acute myocardial infarction?
The administration of beta-blockers reduces cardiac
index, heart rate and blood pressure. The net effect is a
reduction in myocardial oxygen consumption per minute
and per beat, which may benefit the ischemic heart.
The contraindications for beta-blocker therapy in acute
myocardial infarction include the following:
• Heart rate less than 50 to 60 beats per minute
• Systolic blood pressure less than 90 to 100 mmHg
• Severe heart failure requiring intravenous diuretics
or beta-blockers
• Cardiogenic shock
• Asthma or reactive airway disease
• 2nd or 3rd degree atrioventricular block
Beta-blockers are especially helpful for patients
in whom STEMI is complicated by persistent or
recurrent ischemic pain, progressive or repetitive
serum enzyme level elevations suggestive of infarct