Digging Deeper for the Differential Diagnosis of Negative P Waves in Lead I—Reply

Chang et al respond to the comments of Drs Zhao and Wang in their recent case report. As they discussed, dextroposition (when extracardiac factors displace the heart into the right hemithorax) is a consideration in the differential diagnosis of mirror-image dextrocardia. The comments of Zhao and Wang further highlight that the atypical changes seen in electrocardiogram (ECG) manifestations of dextrocardia should raise suspicion for lead misplacement, as well as for conditions that can exert a mass effect on the heart, eg, a left-sided pneumothorax, a hiatal hernia or a previous right-sided pneumonectomy.