How is tachycardia managed in a patient with ST-Elevation Myocardial Infarction (STEMI)?

From the Guidelines

Tachycardia can be a presenting feature in patients with ST-Elevation Myocardial Infarction (STEMI) and requires prompt management to reduce morbidity and mortality. The management of tachycardia in STEMI patients involves identifying and treating the underlying cause, which may include pain, anxiety, heart failure, or the infarction itself 1.

Key Considerations

• Beta-blockers like metoprolol are first-line treatments as they reduce heart rate, blood pressure, and myocardial oxygen consumption while decreasing the risk of ventricular arrhythmias 1.
• However, beta-blockers should be avoided in patients with cardiogenic shock, severe heart failure, bradycardia, or advanced heart block.
• For sinus tachycardia, addressing pain with morphine and anxiety with benzodiazepines may help.
• If the tachycardia is due to atrial fibrillation, rate control with diltiazem or amiodarone may be necessary.
• Supraventricular tachycardias might require adenosine, while ventricular tachycardia may require amiodarone or immediate electrical cardioversion for hemodynamic instability.

Essential Components of Care

• Continuous cardiac monitoring
• Oxygen supplementation to maintain saturation above 94%
• Expedited reperfusion therapy, as early reperfusion therapy reduces the risk of ventricular arrhythmias and cardiovascular death 1. The use of antiarrhythmic drugs in STEMI patients should be done with caution, as the evidence for benefits is limited and negative effects on early mortality have been demonstrated 1.

From the FDA Drug Label

During the intravenous administration of metoprolol tartrate injection, monitor blood pressure, heart rate, and electrocardiogram

• Tachycardia management in STEMI patients involves monitoring heart rate.
• The use of metoprolol tartrate injection in the early phase of acute myocardial infarction, including STEMI, implies that tachycardia can be present in these patients.
• Management of tachycardia in STEMI patients with metoprolol tartrate injection should be done in a setting with intensive monitoring, including monitoring of heart rate 2.

From the Research

Tachycardia in STEMI Patients

• Tachycardia can be a complication in patients with ST-Elevation Myocardial Infarction (STEMI) 3
• Cardiac arrest, which can be associated with tachycardia, is a major complication of STEMI, with a prevalence of 7.5% in contemporary US practice 3

Management of Tachycardia in STEMI Patients

• Antithrombotic therapy, including antiplatelet and anticoagulant agents, is the cornerstone of pharmacological treatment to optimize clinical outcomes in patients with STEMI undergoing primary percutaneous coronary intervention (PPCI) 4, 5
• Dual antiplatelet therapy with aspirin and an oral P2Y12-receptor inhibitor is pivotal for the acute and long-term treatment of patients with STEMI undergoing PPCI 4
• However, there is no direct evidence on the management of tachycardia in STEMI patients in the provided studies

Clinical Characteristics and Outcomes

• STEMI patients with cardiac arrest, which can be associated with tachycardia, have higher inhospital mortality rates compared to those without cardiac arrest (28.8% vs 4.0%) 3
• Cardiogenic shock and cardiac arrest frequently coexist in STEMI patients, and the development of systems of care and treatments for both STEMI and cardiac arrest is needed to reduce the high mortality in these patients 3