Case of a misleading ECG

Area of Science:

• Cardiology
• Medical Imaging
• Pulmonology

Background:

• Pacemaker lead infections necessitate device extraction.
• Electrocardiogram (ECG) interpretation can be challenging in patients with cardiac devices and underlying conditions.
• Chronic obstructive pulmonary disease (COPD) can significantly alter thoracic anatomy.

Purpose of the Study:

• To describe a case of pacemaker lead infection.
• To highlight potential misinterpretation of ECG findings in a patient with COPD and cardiac displacement.
• To illustrate the impact of cardiac displacement on ECG interpretation of ventricular pacing.

Main Methods:

• Case report of an elderly male patient.
• Review of electrocardiogram (ECG) findings.
• Computed tomography (CT) scan for anatomical assessment.
• Pacemaker device interrogation and lead assessment.

Main Results:

• The patient presented with pacemaker lead infection requiring device extraction.
• ECG showed paced QRS complexes with morphology suggestive of left ventricular pacing (R wave in V1, QS in lead I).
• CT scan revealed significant leftward and posterior displacement of the heart due to severe COPD.
• This anatomical displacement explained how right ventricular pacing could mimic left ventricular pacing on ECG.

Conclusions:

• Severe COPD can cause cardiac displacement, altering ECG morphology.
• Right ventricular pacing in a displaced heart may be misinterpreted as left ventricular pacing.
• Awareness of anatomical changes due to pulmonary disease is crucial for accurate ECG interpretation in pacemaker patients.