ECG Case 021

This ECG demonstrates many of the features of chronic pulmonary disease:

• Rightward QRS axis (+90 degrees).
• Peaked P waves in the inferior leads > 2.5 mm (P pulmonale).
• Rightward P-wave axis (inverted in aVL).
• “Clockwise rotation” of the heart with a delayed R/S transition point (transitional lead = V5).
• Absent R waves in the right precordial leads (SV1-SV2-SV3 pattern).
• Low voltages in the left-sided leads (I, aVL, V5-6).

Tachycardia may be due to dyspnoea, hypoxia or beta-agonist treatment. This ECG pattern is a common finding in patients with COPD. The vertical axis (+90 degrees) is due to hyperinflation of the lungs causing vertical orientation of the heart.