Acute myocardial infarction complicated by shock: outcome analysis based on initial electrocardiogram

Area of Science:

• Cardiology
• Critical Care Medicine
• Electrocardiography

Background:

• Acute myocardial infarction (AMI) can lead to cardiogenic shock (CS), a life-threatening condition.
• Initial electrocardiogram (ECG) findings and patient risk factors are crucial for predicting outcomes in AMI patients.
• Understanding the relationship between ECG patterns and CS development is vital for timely intervention.

Purpose of the Study:

• To investigate the association between initial ECG findings, risk factors, coronary angiography results, and clinical outcomes in AMI patients with CS.
• To determine the predictive value of different ECG classifications (STEMI, STDMI, BBBMI, other) for CS development and mortality.
• To identify specific ECG patterns associated with severe coronary artery disease and poor prognosis.

Main Methods:

• Analysis of data from 5572 AMI patients admitted to tertiary hospitals over 3 years.
• Identification of 358 patients (6.4%) who developed CS on admission.
• Classification of patients into four groups based on admission ECG: STEMI, STDMI, BBBMI, and other AMI ECG findings.

Main Results:

• Cardiogenic shock occurred most frequently in bundle branch block myocardial infarction (BBBMI) patients (12.1%), particularly those with right bundle branch block (RBBB) (11.2%) and left bundle branch block (LBBB) (13.3%).
• One-year mortality was highest in RBBB patients (66.7%) and LBBB patients (48.6%), significantly exceeding other ECG groups.
• RBBB was associated with increased risk of CS, left main coronary artery disease, and unsuccessful revascularization.

Conclusions:

• Right bundle branch block (RBBB) on admission ECG is a significant predictor of cardiogenic shock development in acute myocardial infarction.
• RBBB is independently associated with the highest one-year mortality risk among AMI patients.
• Early identification of RBBB on ECG is crucial for risk stratification and management of AMI patients prone to cardiogenic shock.