Clinicall Revie Clinica Review w & Educa Education tion
Challenges Challe nges in Clinica Clinicall Electro Electrocardio cardiograph graphy y
Electroca Electr ocardi rdiogr ograph aphic ic Fin Findin dings gs in a Woma oman n Wi With th Dex Dextro trocar cardia dia and Cya Cyanos nosis is YingjieZhan Yi ngjieZhang, g, MD;HexiJian MD;HexiJiang, g, MD;Reng MD;Renguan uang g Liu Liu,, MD
A 31-year-old woman with woman with a history of progressive cyanosis and dyspnea dyspn ea sinc since e child childhooddevelope hooddeveloped d chesttightne chesttightness ss and short shortness ness of breath in the 20 days after a cold and was admitted to the hospital.Onadmission,herbloodpressurewas108/70mmHg,herheart rate rat e wa wass 84beatsperminut 84beatsperminute,andher e,andher resp respira irator tory y rat rate e was22breat was22breaths hs per minute. Physical examination revealed lip cyanosis; the apex beat was located at 0.5 cm outside of the right clavicle line; and a systolic ejection murmur was detected at the third and fourth intercostal at the right side of the sternum. The B-type natriuretic peptide level was substantially increased. The 12-lead electrocardiogram diog ram (EC (ECG) G) (Fig Figure1 ure1)) sho showednega wednegativ tive e P wa wave ve inleadsaVL and I but positive P wave in lead aVR. QRS complexes presented as rS complex in lead V1 and QR in V 2 to V 6. The amplitude of R wave decreased decrea sed progr progressiv essively ely from lead V2 to V6. Question:: How should the ECG be analyzed and how to Question further diagnose?
Interpretation After limb leads misconnection was excluded, 2 possible reasons wereconsider werecons idered ed forthe abn abnorm ormalrightalright-axisdevi axisdeviati ationof onof theP wav wave. e. One was mirro mirror-im r-image age dext dextroca rocardia, rdia, in which the patie patient’ nt’ss ecto ectopic pic heartis rever reverselylocatedin selylocatedin theright thor thorax.However ax.However,, theQR complex ple x inleadsV 2 to V6 did notsupport the diag diagnosi nosiss of mirro mirror-im r-image age dextrocardia.The dextroc ardia.The secondpossible diagno diagnosis sis wasdextroversio wasdextroversion n with left atria atriall rhyth rhythm, m, cons considerin idering g the patie patient’ nt’ss cong congenit enital al cyan cyanosis osis.. The echo echocardi cardiogra ogram m sugge suggested sted tetra tetralogy logy of Fal Fallot lot and mirro mirrorrimage imag e dextr dextrocar ocardia. dia. The tetra tetralogy logy of Fal Fallot lot was revea revealed led as pulmo pulmo-nary sten stenosis osis and righ rightt vent ventricul ricular ar outfl outflow ow trac tractt obst obstructi ruction, on, over over-riding ridin g aort aortaa ove overr theventric theventricularseptaldefect,the ularseptaldefect,the vent ventricul ricular ar sept septal al defectt of 22mm in diame defec diameter ter,, andthe rightventri rightventricula cularr hyper hypertroph trophy y. The Th e bid bidire irecti ction onal al flo flow w thr throug ough h the ven ventri tricul cular ar sep septa tall def defect ect wit with ha left-to-right dominance was detected. Moreover, mirror imaging
ofthe norm normalvisceraland alvisceraland atri atrium um waspresent;the cardi cardiac ac apexwas pointingto poin tingto theright;and theaorticarch desce descendin nding g reve reversedto rsedto the rightt thor righ thorax. ax. The ECG leads were relocated to change the mirror imaging into a normal one (Figure ( Figure 2). 2). For this correction, the left arm lead was placed on the right arm; the right arm lead was placed on the left arm; and the precordial leads were placed across the right rather than the left precordium (with the V1-V6 leads placed in the V2, V1,andV3R-V6R pos positio itions). ns). On the corr corrected ected ECG ECG,, sinu sinuss rhyt rhythm hm wass in wa indi dica cate ted d bythe po posi siti tiveP veP wa wavein vein le lead adss I,II, an and d aV aVL, L, an and d th the e negative P wave in lead aVR; right ventricular hypertrophy was suggested by the QRS axis deviated to the right (+120°), qR complex in lead V1, and the voltage of the S wave in lead V 5 over 0.5 mV. The patient refused surgery and was discharged when her symptom sym ptomss were reli relieved eved..
Discussion In general, the heart shift to the right thorax is referred to as dextrocardia, including mirror-image dextrocardia, heart dextroversion, and heart dextroposition. 1,2 Mirror-image dextrocardia is characterized by mirror-image change of the normal heart generally accompanied by situs inversus viscerum, but only 3% to 10% of patients have intracardiac anomaly. 3,4 The ECG is characteri characterized zed by negative P wave in leads I and aVL, and positive P wave in lead aVR; aV R; th the e QR QRS S co compl mplex exes es in lea leads ds V1 thro through ugh V6 indi indicat cate e the acti activava5 tion of the ventricle in the right thorax. Cardiac dextroversion refers to the heart rotation into the right thorax with its normal chambers and adjacency relations, although the axis of the heart still points to the left. No situs inversus viscerum exists, but the intracardiac anomaly is commonly seen. The ECG reveals positive P wa wavein vein le leadI adI an and d QR QRS S co comp mple lexe xess inlea inleadsV dsV1 thro through ugh V6, indicating the activation of the ventricle in the right thorax. 6 Heart
Figure Figu re 1. Initi Initial al Elect Electroca rocardiog rdiogram ram
I
aVR
V1
V4
II
aVL
V2
V5
III
aVF
V3
V6
Standard Stand ard 12-le 12-lead ad elect electrocardio rocardiogram gram on admiss admission. ion.
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Clinical Review & Education Challenges in Clinical Electrocardiography
Figure 2. ElectrocardiogramAfter Correction I
aVR
V1
V4
II
aVL
V2
V5
III
aVF
V3
V6
The12-lead electrocardiogramrecorded basedon the correction method of the mirror-image dextrocardia.
dextroposition presents under the situation of severe extracardiac abnormalities, such as lung, pleural, or diaphragmatic disease; these pathological changes push the heart rightward, even into the right thorax, but the heart structure is normal. 2 The ECG reveals normal QRS complex in precordial leads, and the QRS voltage progressively decreases from lead V4 to V6. The characteristics of P wave and QRS complex are helpful to make a differentiation diagnosis between the 3 types of dextrocardia. Situs inversus viscerum and congenital cyanosis are helpful for the primary diagnosis of congenital heart disease. Finally, echocardiography is reliable for the definite diagnosis. A corrected 12-lead ECG is helpful to recognize mirror-image dextrocardia in the situation without single ventricle anomaly.3 In this patient, the negative P wave in lead I suggested mirrorimage dextrocardia, but QRS complex in lead V 1 did not support this conclusion. Given the congenital cyanosis, dextroversion
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with left atrial rhythm was reasonably suspected. Finally, mirrorimage dextrocardia with tetralogy of Fallot was verified by echocardiography.
Take-Home Points • There are 3 conditions classified as dextrocardia: mirror-image dextrocardia, dextroversion, and dextroposition. In them, the anatomic and clinical conditions and ECG manifestations are different from one another. • The characteristics of abnormal P wave in lead I and QRS complex in precordial leads are helpful to detect mirror-image dextrocardia. • Situs inversus viscerum and congenital cyanosis are helpful to find the underlying congenital heart disease. • Echocardiography is reliable for the definite diagnosis.
ARTICLE INFORMATION
Conflict of Interest Disclosures: Nonereported.
Author Affiliations: Cardiovascular Departmentof theFirst Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning Province, China (Zhang, Jiang); Cardiovascular Instituteof theFirst Affiliated Hospital of Jinzhou Medical University, Jinzhou, Liaoning Province, China(Liu).
Additional Contributions: Wethank thepatientfor granting permission to publishthis information.
Corresponding Author: RenguangLiu, MD, Cardiovascular Instituteof theFirst Affiliated Hospital of Jinzhou Medical University, Renmin Street, Jinzhou, Liaoning Province, China (
[email protected]).
2. Maldjian PD, Saric M. Approach to dextrocardia in adults: review [review]. AJR Am J Roentgenol . 2007;188(6)(suppl):S39-S49.do i:10.2214 /AJR.06.1179
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3. Li Y, LiuR, ZhangX. Dextrocardia: why significantleft-axisdeviation?Circulation. 2017;136 (17):1662-1664.doi:10.1161/CIRCULATIONAHA.117 .031095
Published Online: June25, 2018. doi:10.1001/jamainternmed.2018.2682
4. Reiffel JA.ECG response:can youmakethe correctmorphology, pathology, and rhythm
JAMAInternalMedicine Publishedonline June 25, 2018 (Reprinted)
diagnoses? Circulation. 2016;134(7):567-569. doi:10.1161/CIRCULATIONAHA.116.024356 5. Bharati S,Lev M. Positional variationsof the heartand its component chambers. Circulation. 1979;59(5):886-887. doi:10.1161/01.CIR.59.5.886 6. GrantRP. Thesyndrome of dextroversionof the heart. Circulation. 1958;18(1):25-36. doi:10.1161 /01.CIR.18.1.25
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