Right-sided EKG in Pulmonary Embolism

Purpose: To identify right-sided chest lead electrocardiographic abnormalities in acute pulmonary embolism.

Patients And Methods: Analysis of electrocardiographic changes in 100 African American patients suspected of having pulmonary embolism was made at Howard University Hospital during 2001-02 (60% women, 40% men, median age 50 years). Standard 12-lead EKGs were obtained within one hour of arrival to emergency room. Right-sided EKGs were obtained within 24 hours of onset of symptoms of pulmonary embolism. Parameters of both right- and left-sided EKGs available were measured and compared.

Results: Only 20% of these patients were diagnosed with pulmonary embolism. EKG changes (three of seven) suggestive of acute right ventricular strain were found in both right- and left-sided leads in 16 (80%) patients diagnosed with pulmonary embolism. These EKG changes disappeared within 24 hours of admission in 14 (87.5%) patients. Four patients with a diagnosis of pulmonary embolism had normal left-sided EKGs but the right-sided EKGs showed ST segment elevation and a qr or qs pattern (prominent q waves) in one to three of the leads V4R, V5R and V6R. These patterns were also seen in 10 of the 16 patients showing right ventricular strain pattern in their EKGs. Non-specific ST-T wave changes were seen in 20 (25%) patients not considered to have pulmonary embolism. V3R leads showed rS configuration in 90% of the patients.

Conclusion: EKG changes in right-sided chest leads occur frequently in pulmonary embolism. The diagnostic potential of routinely recorded right-sided EKG appears to be greatest in patients with acute pulmonary embolism not manifesting typical changes in their standard 12-lead EKGs. This study also confirms previous case reports observing similar changes in the right-sided leads.