CARDIOVASCULAR EMERGENCIES
TABLE 2.6. Indications for Reperfusion Therapy in STEMIIndications for Thrombolytic Therapy or PCI in AMI1 mm ST elevation in two contiguous limb leads2 mm ST elevation in two contiguous precordial leadsNew LBBBAdministration of a b-blocker
in MI →↓incidence of VFib
and has a significant impact
on long-term mortality.■ IV ACE after MI may cause hypotension, so administer orally.
■ Contraindications:
■ Pregnancy
■ History of angioedema
■ SBP<100 mmHg
■ Renal failure
■ Hyperkalemia
■ Angiotensin receptor blockers (ARBs) may be used in patients with ACE
inhibitor intolerance.
■ HMG coenzyme A reductase inhibitors (statins)
■ Less commonly initiated in ED
■ ↓Incidence of recurrent angina and subsequent MIs
■ Calcium channel blocker
■ Indicated for the treatment of coronary vasospasm only
■ Otherwise, has been shown to increase mortalityReperfusion Therapy: Percutaneous Coronary
Intervention (PCI) Versus Thrombolytic Therapy
■ PCI consists of catheterization with angioplasty and stent placement.
■ Thrombolytics bind plasminogen, which then degrades fibrin, “busting
clots.” The primary risk of thrombolytic therapy is bleeding (including
intracranial hemorrhage).
■ Alteplase (tPa)—front-loaded or accelerated
■ Reteplase (rPA)
■ Tenecteplase (TNK)
■ Indications for reperfusion therapy include 1–2 mm ST elevation in regional
distribution or new LBBB (see Table 2.6).
■ PCI is generally preferred in the setting of STEMI if
■ Transfer to a PCI facility can be accomplished within 2 hours. How-
ever, the goal is always a door to balloon time <90 minutes.
■ Presentation >3 hours after onset of symptoms
■ Uncertain diagnosis
■ Complications (CHF, unstable)
■ Contraindications to thrombolytics (see Table 2.7)
■ Most effective PCI centers perform >200 PCIs per year.
■ Commonly seen rhythm following reperfusion =accelerated idioven-
tricular rhythm (AIVR)—benign and rarely requires treatment (see
Figure 2.13)See Table 2.8 for a summary of agents used in the treatment of ACS.