What diagnosis should I document for a patient referred to pulmonary services who has an ECG showing right‑heart strain (e.g., sinus tachycardia, S1Q3T3 pattern, right bundle‑branch block, or anterior T‑wave inversions)?

Diagnosis Documentation for Pulmonary Referral with Abnormal ECG

Document "suspected pulmonary hypertension" or "pulmonary hypertension with right ventricular strain" as your primary diagnosis when referring a patient to pulmonary services with ECG findings of right-heart strain. 1

Primary Diagnostic Approach

When ECG shows right-heart strain patterns (S1Q3T3, right bundle branch block, right axis deviation, T-wave inversions in V1-V4, or sinus tachycardia), you must first determine whether this represents:

• Acute pulmonary embolism (if acute presentation with dyspnea, chest pain, or hemodynamic instability) 1, 2
• Chronic pulmonary hypertension (if chronic dyspnea, fatigue, or progressive symptoms) 1
• Underlying lung disease (COPD, interstitial lung disease) 1

ECG Findings and Their Clinical Significance

Right Ventricular Strain Patterns

The ECG abnormalities you're seeing indicate right ventricular pressure or volume overload: 1

• Right axis deviation and RV hypertrophy suggest chronic pulmonary hypertension, particularly when accompanied by P pulmonale 1
• RV strain pattern (T-wave inversions in V1-V4) has 97.4% specificity for significant RV dysfunction and indicates more severe disease 2, 3
• S1Q3T3 pattern suggests acute RV strain, most commonly from pulmonary embolism, though it has limited sensitivity 2, 4
• Right bundle branch block (complete or incomplete) occurs in 4.8-9% of PE cases and correlates with RV strain 3, 5

Critical Distinction: Acute vs. Chronic

For acute presentations (hours to days of symptoms):

• Document "suspected acute pulmonary embolism" if dyspnea, chest pain, tachycardia, or hemodynamic instability are present 1, 2
• The ECG serves primarily to exclude acute MI and assess disease severity, not to diagnose PE definitively 2, 3
• Obtain urgent CT pulmonary angiography or V/Q scan for definitive diagnosis 1

For chronic presentations (weeks to months of progressive symptoms):

• Document "suspected pulmonary hypertension" or "pulmonary arterial hypertension" 1
• ECG sensitivity for RV hypertrophy is only 55%, but when present with right axis deviation, it strongly suggests hemodynamically significant pulmonary hypertension 1
• The pulmonary specialist will perform echocardiography and right heart catheterization for definitive diagnosis 1

Specific Documentation Recommendations by Clinical Scenario

Scenario 1: Chronic Dyspnea with RV Hypertrophy Pattern

Document: "Pulmonary hypertension, suspected" or "Right ventricular hypertrophy, etiology undetermined" 1

• Right axis deviation (≥100°) plus RV hypertrophy criteria (R/S ratio in V1 ≥1, R wave in V1 ≥0.5 mV) indicate chronic pressure overload 1
• P pulmonale (P wave ≥2.5 mm in leads II, III, aVF) suggests right atrial enlargement from chronic pulmonary hypertension 1
• QRS prolongation and QTc prolongation suggest severe disease 1

Scenario 2: Acute Dyspnea with S1Q3T3 or RV Strain

Document: "Suspected acute pulmonary embolism" or "Acute right ventricular strain, etiology undetermined" 1, 2

• S1Q3T3 pattern has positive likelihood ratio of 2.07 but must be integrated with clinical probability scores (Wells or Geneva) 2, 4
• T-wave inversions in V1-V4 are the most specific finding (97.4%) for acute RV strain 2, 3
• Sinus tachycardia alone is non-specific but present in 40% of PE cases 3, 5

Scenario 3: COPD Patient with Right Axis Deviation

Document: "Chronic obstructive pulmonary disease with suspected cor pulmonale" 1

• COPD causes characteristic ECG pattern: low voltage in limb leads, rightward/superior axis, persistent S waves in precordial leads, low R-wave amplitude in V6 1
• RV hypertrophy in COPD is suggested only if R-wave amplitude in V1 is relatively increased despite the COPD pattern 1
• Accuracy of ECG for RV hypertrophy is lowest in chronic lung disease compared to other causes 1

Common Pitfalls to Avoid

Do not document "rule out MI" when RV strain pattern is present—this delays appropriate PE or pulmonary hypertension workup 2, 3

• ECG changes in ischemia affect lateral and inferior leads, rarely cause right axis deviation, and typically show Q waves in V1-V3 when anterior leads are involved 1
• RV strain pattern specifically affects right precordial leads (V1-V4) without Q waves 1

Do not rely on ECG alone for diagnosis—it has insufficient sensitivity (55%) and specificity (70%) for pulmonary hypertension 1

• Normal ECG does not exclude pulmonary hypertension or PE 1
• ECG is more useful for risk stratification than diagnosis 2, 3

Do not miss alternative diagnoses:

• Atrial arrhythmias (atrial flutter, atrial fibrillation) occur in 10-25% of pulmonary hypertension patients and indicate advanced disease 1
• Right bundle branch block may be congenital or from other causes of RV pressure overload 1

Supporting Documentation for Referral

Include these additional findings to strengthen your referral: 1

• Chest X-ray findings: Central pulmonary artery dilatation, peripheral vascular pruning, or signs of lung disease 1
• Clinical context: Duration of symptoms, risk factors for PE (immobilization, surgery, malignancy), or risk factors for pulmonary hypertension (connective tissue disease, HIV, portal hypertension) 1
• Physical examination: Elevated JVP, RV heave, loud P2, tricuspid regurgitation murmur, peripheral edema 1
• Functional status: WHO functional class or 6-minute walk distance if available 1