What is the management approach for a patient presenting with left vs right ventricular strain pattern on an electrocardiogram (ECG)?

ECG Ventricular Strain Patterns: Recognition and Management

Immediate Recognition and Differentiation

Right ventricular (RV) strain pattern on ECG indicates acute pulmonary embolism until proven otherwise and requires immediate diagnostic workup, while left ventricular (LV) strain pattern suggests chronic pressure overload from hypertension or aortic stenosis and warrants risk stratification for acute coronary syndrome. 1

Right Ventricular Strain Pattern

ECG Features:

• Complete or incomplete right bundle branch block (RBBB) 2
• S1Q3T3 pattern (deep S wave in lead I, Q wave in lead III, inverted T wave in lead III) 2
• Negative T waves in leads V1-V4 2, 3
• Any one or more of these findings constitutes RV strain 2

Clinical Significance:

• RV strain is present in 34% of normotensive patients with acute pulmonary embolism 2
• Independently predicts clinical deterioration or death (hazard ratio 2.58) even when blood pressure is normal 2
• When combined with echocardiographic RV dysfunction, the risk of adverse outcomes increases 8-fold (hazard ratio 8.47) 2
• In COVID-19 patients, RV strain predicts in-hospital mortality (OR 4.385) independent of other factors 3

Immediate Management Algorithm:

1. Obtain CT pulmonary angiography immediately if RV strain is present with chest pain or dyspnea 1
2. Measure troponin and D-dimer—elevated troponin can occur with PE due to RV myocardial injury 4
3. Perform bedside echocardiography to assess RV size and function 2
4. Initiate anticoagulation immediately if PE is confirmed or highly suspected 4
5. Consider thrombolysis or catheter-directed therapy if hemodynamic instability develops 1

Left Ventricular Strain Pattern

ECG Features:

• Downsloping convex ST-segment depression with inverted asymmetrical T waves in leads V5 and/or V6 5
• ST-T wave changes opposite to the QRS axis 5
• Typically occurs in the setting of ECG criteria for left ventricular hypertrophy 6, 5

Clinical Significance:

• Present in 11% of hypertensive patients with ECG-LVH 5
• Independently predicts cardiovascular death (hazard ratio 1.53), myocardial infarction (hazard ratio 1.55), and composite cardiovascular endpoints (hazard ratio 1.33) even with aggressive blood pressure control 5
• Sensitivity for detecting LVH ranges from 3.8-50%, but specificity is 89.8-100% 6
• Among patients presenting with chest pain, only 26% with ECG-LVH actually have acute cardiac ischemia, compared to 72% with primary ST-T wave changes 7

Critical Diagnostic Pitfall:

• Admitting physicians correctly identify ECG-LVH in only 22% of cases—in over 70% of cases, the secondary ST-T wave changes are misread as primary ischemic changes 7
• Do not administer thrombolytic therapy based solely on ST-segment changes in the presence of LVH, as acute MI is only one-fourth as likely (12%) compared to primary ST-segment abnormalities (48%) 7

Management Algorithm for LV Strain with Chest Pain:

1. Obtain serial troponin measurements at presentation and 6-12 hours to detect rising or falling patterns 4
2. Do not wait for troponin results if clinical suspicion for STEMI is high based on symptoms and ECG evolution 1, 4
3. Perform echocardiography to assess for regional wall motion abnormalities—these occur within seconds of coronary occlusion and distinguish acute ischemia from chronic LVH 1
4. If troponin is elevated with ongoing symptoms, proceed to coronary angiography regardless of LV strain pattern 8
5. If troponin is negative and symptoms resolve, consider stress testing or coronary CT angiography for risk stratification 1

Risk Stratification Framework

High-Risk Features Requiring Immediate Intervention (regardless of strain pattern): 8, 9

• Prolonged ongoing rest pain >20 minutes
• Hemodynamic instability (hypotension, shock)
• Severe dyspnea or pulmonary rales
• New or worsening heart failure signs
• Elevated troponin above 99th percentile

Intermediate-Risk Features:

• RV strain with normal blood pressure but elevated D-dimer and troponin 2
• LV strain with atypical symptoms in women, elderly, or diabetic patients 8

Special Considerations

When Both Conditions May Coexist:

• A patient with chronic LV strain pattern on anticoagulation for prior PE can still develop acute coronary syndrome 4
• Obtain both troponin and D-dimer, perform echocardiography to assess both ventricles 4
• Consider CT pulmonary angiography if clinical suspicion for recurrent PE exists, especially with shock or syncope 4

Posterior MI Mimicking RV Strain:

• Posterior MI presents with ST-depression in V1-V4, which can be confused with RV strain 9
• Key distinction: posterior MI shows horizontal ST-depression with upright T waves, while RV strain shows negative T waves in V1-V4 9, 2
• Obtain posterior leads (V7-V8) if posterior MI is suspected 1
• Treat posterior MI as STEMI-equivalent with immediate reperfusion therapy 9

Prognostic Implications:

• Short-term mortality with LV strain pattern is 7.5%, intermediate between primary ST-T abnormalities (10.6%) and other ECG findings (5.1%) 7
• RV strain in normotensive PE patients identifies a subgroup requiring closer monitoring and potential escalation of therapy 2