What vasopressor (pressor) can be used in a patient with ST-Elevation Myocardial Infarction (STEMI) and hypotension?

Management of Hypotension in STEMI

In a patient with STEMI and hypotension, norepinephrine is the preferred vasopressor after initial volume loading has failed to restore blood pressure. 1, 2

Initial Assessment and Management

1. First-line management:

   • Rapid volume loading with IV infusion should be administered if no clinical evidence of volume overload 1
   • Correct any rhythm disturbances or conduction abnormalities causing hypotension 1
   • Perform echocardiography to evaluate for mechanical complications (ventricular septal rupture, papillary muscle rupture, free wall rupture) 1

2. When to use vasopressors:

   • Vasopressor support should be initiated when hypotension does not resolve after adequate volume loading 1

Vasopressor Selection for STEMI with Hypotension

Norepinephrine (First Choice)

• Dosing: 2

  • Dilute 4 mg in 1000 mL of 5% dextrose solution (4 mcg/mL)
  • Initial dose: 2-3 mL/min (8-12 mcg/min)
  • Adjust to maintain systolic BP 80-100 mmHg
  • Average maintenance dose: 0.5-1 mL/min (2-4 mcg/min)
  • Titrate according to patient response

• Administration: 2

  • Use a large vein with central venous access preferred
  • Administer via IV infusion with accurate rate control
  • Monitor blood pressure continuously

Important Considerations

• Avoid inotropes in certain situations:

  • Beta-blockers and calcium channel antagonists should not be administered to patients in a low-output state due to pump failure 1
  • Inotropes like dobutamine may worsen hypotension in patients with LVOT obstruction associated with Takotsubo cardiomyopathy 3

• Special considerations for women:

  • Female patients have a higher incidence of hypotensive episodes during STEMI 4, 5
  • Women may require more careful titration of vasopressors

Additional Supportive Measures

1. Mechanical support:

   • Intra-aortic balloon counterpulsation should be performed in patients who do not respond to vasopressors 1
   • IABP is recommended as a stabilizing measure for angiography and prompt revascularization 1

2. Definitive management:

   • Urgent coronary revascularization (PCI or CABG) is strongly recommended for suitable candidates with cardiogenic shock 1
   • Emergency surgical repair may benefit patients with mechanical complications 1

Monitoring and Titration

• Continuous arterial pressure monitoring is recommended for patients requiring vasopressor support 1
• Central venous pressure monitoring is helpful in detecting and treating occult volume depletion 1
• Gradually reduce vasopressor infusion, avoiding abrupt withdrawal 2
• In some cases of vascular collapse due to acute myocardial infarction, vasopressor treatment may be required for up to six days 2

Pitfalls to Avoid

1. Do not delay reperfusion therapy while managing hypotension - the primary goal remains rapid restoration of coronary blood flow 6

2. Avoid excessive fluid administration in patients with pulmonary congestion - this can worsen heart failure 1

3. Do not use inotropes indiscriminately - in some cases of STEMI with LVOT obstruction, inotropes can worsen hypotension 3

4. Avoid using vasopressors without adequate volume resuscitation - occult hypovolemia should always be suspected and corrected when present 1, 2

5. Do not delay mechanical support in patients who fail to respond to initial pharmacological therapy 1