Dextrocardia
Also calleddextrocardia · mirror-image dextrocardia · mirror-image ECG
Definition
A congenital positional anomaly in which the heart lies in the right hemithorax with its base-to-apex axis pointing to the right. In mirror-image dextrocardia (with situs inversus) the limb leads resemble an accidental swap of the arm electrodes, with negative P, QRS and T waves in lead I. Unlike an arm-electrode swap, the chest leads are also abnormal: R-wave progression is reversed and the QRS becomes small, mostly QS or rS, from V3 through V6. The tracing looks normal when the arm electrodes are deliberately reversed and the chest electrodes are placed in mirror-image positions on the right chest. By contrast, an arm-electrode swap on a normally placed heart inverts lead I but leaves the chest leads unchanged. When dextrocardia occurs without situs inversus (dextroversion), the atria keep their normal arrangement, and the P-wave and QRS axes fall in different quadrants.
Clinical noteThe abnormal chest-lead pattern, absent in an isolated arm-electrode swap, is the key point separating true mirror-image dextrocardia from a lead-placement error.
Sources
- Ogunlade O, Ayoka AO, Akomolafe RO, et al. The role of electrocardiogram in the diagnosis of dextrocardia with mirror image atrial arrangement and ventricular position in a young adult Nigerian in Ile-Ife: a case report. J Med Case Rep. 2015;9:222. doi.org/10.1186/s13256-015-0695-4
- Batchvarov VN, Malik M, Camm AJ. Incorrect electrode cable connection during electrocardiographic recording. Europace. 2007;9(11):1081-1090. doi.org/10.1093/europace/eum198
- Maldjian PD, Saric M. Approach to dextrocardia in adults: review. AJR Am J Roentgenol. 2007;188(6 Suppl):S39-S49. doi.org/10.2214/AJR.06.1179
- Kligfield P, Gettes LS, Bailey JJ, et al. Recommendations for the standardization and interpretation of the electrocardiogram: part I: the electrocardiogram and its technology. Circulation. 2007;115(10):1306-1324. doi.org/10.1161/CIRCULATIONAHA.106.180200
- Samesima N, God EG, Kruse JCL, et al. Brazilian Society of Cardiology guidelines on the analysis and issuance of electrocardiographic reports - 2022. Arq Bras Cardiol. 2022;119(4):638-680. doi.org/10.36660/abc.20220623
Last reviewed 2 October 2026. Every definition in the EKG Dictionary cites the guideline, consensus statement or original paper it comes from.