THE CLINICAL PICTURE PRASHANT SHARMA, MD VIJAIGANESH NAGARAJAN, MD, MRCP DONALD A. UNDERWOOD, MD Department of Hospital Internal Medicine, Department of Cardiovascular Medicine, University of Department of Cardiovascular Medicine, Mayo Clinic, Rochester, MN Virginia, Charlottesville Cleveland Clinic
Heart on the right may sometimes be ‘right’
Negative complexes FIGURE 1. The standard left-sided 12-lead electrocardiogram showed right-axis deviation; inverted P, QRS, and T waves in leads I and aVL (arrows), and positive complexes in lead in lead I, aVR (circle). Leads V1–V6 showed reversal of R-wave progression. positive complexes 76-year-old man presented to the In patients with dextrocardia, right-sid- A emergency department with right-sided ed hookup of the electrodes is usually neces- in aVR, and exertional chest pain radiating to the right sary for proper interpretation of the ECG. slight reversal shoulder and arm associated with shortness of When this was done in our patient, the breath. His vital signs were normal. On clini- ECG showed a normal cardiac axis, a nega- of R-wave cal examination, the cardiac apex was palpat- tive QRS complex in lead aVR, a positive progression ed on the right side, 9 cm from the midsternal P wave and other complexes in lead I, and line in the fi fth intercostal space. normal R-wave progression in the precordial indicate A standard left-sided 12-lead electrocar- leads—fi ndings suggestive of dextrocardia dextrocardia diogram (ECG) showed right-axis deviation (FIGURE 2). and inverted P, QRS, and T waves in leads I Chest radiography showed a right-sided and aVL (FIGURE 1). Although these changes cardiac silhouette (FIGURE 3), and computed to- are also seen when the right and left arm elec- mography of the abdomen (FIGURE 4) revealed trode wires are transposed, the precordial lead the liver positioned on the left side and the morphology in such a situation would usually spleen on the right, confi rming the diagnosis be normal. In our patient, the precordial leads of situs inversus totalis. The ECG showed dex- showed the absence or even slight reversal of trocardia, but no other abnormalities. The pa- R-wave progression, a feature indicative of tient eventually underwent coronary angiog- dextrocardia.1,2 raphy, which showed nonobstructive coronary doi:10.3949/ccjm.81a.13163 artery disease.
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FIGURE 2. With right-sided hookup in the same patient, the electrocardiogram showed a normal QRS axis, positive QRS complexes in leads I and aVL (arrows), negative QRS com- plexes in lead aVR (circle), and normal R-wave progression.
■ DEXTROCARDIA, OTHER CONGENITAL Risk factors CARDIOVASCULAR MALFORMATIONS The cause of congenital cardiovascular mal- Dextrocardia was fi rst described in early 17th formations such as these is not known, but century.1 Situs solitus is the normal position of risk factors include positive family history, maternal diabetes, and cocaine use in the fi rst People the heart and viscera, whereas situs inversus is trimester.7 a mirror-image anatomic arrangement of the with situs The prevalence of congenital heart disease organs. Situs inversus with dextrocardia, also in patients with situs inversus with dextrocar- inversus with called situs inversus totalis, is a rare condition dia is low and ranges from 2% to 5%. This is in dextrocardia (with a prevalence of 1 in 8,000) in which the contrast to situs solitus with dextrocardia (iso- heart and descending aorta are on the right and lated dextrocardia), which is almost always as- are usually the thoracic and abdominal viscera are usually sociated with cardiovascular anomalies.2,4 Kart- asymptomatic mirror images of the normal morphology.1,3,4 A agener syndrome—the triad of situs inversus, and have a mirror-image sinus node lies at the junction of sinusitis, and bronchiectasis—occurs in 25% of the left superior vena cava and the left-sided people with situs inversus with dextrocardia.4 normal life 1 (morphologic right) atrium. People with situs Situs inversus with levocardia is also frequently expectancy inversus with dextrocardia are usually asymp- associated with cardiac anomalies.5 1,2 tomatic and have a normal life expectancy. The major features of dextrocardia on Situs inversus with levocardia is a rare condi- ECG are: tion in which the heart is in the normal posi- • Negative P wave, QRS complex, and T tion but the viscera are in the dextro-position. wave in lead I This anomaly has a prevalence of 1 in 22,000.5 • Positive QRS complex in aVR Atrial situs almost always corresponds to • Right-axis deviation visceral situs. However, when the alignment • Reversal of R-wave progression in the pre- of the atria and viscera is inconsistent and si- cordial leads. tus cannot be determined clearly because of Ventricular activation and repolarization the malpositioning of organs, the condition are reversed, resulting in a negative QRS is called “situs ambiguous.” This is very rare, complex and an inverted T wave in lead I. with a prevalence of 1 in 40,000.6 The absence of R-wave progression in the pre-
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FIGURE 3. Chest radiography confi rmed dextrocardia, showing a right-sided cardiac FIGURE 4. Computed tomography of the apex and a right-sided aortic arch (AoA). abdomen confi rmed situs inversus totalis, with the liver (L) on the left side and the spleen (S) on the right side.
cordial leads helps differentiate mirror-image and the aortic arch.8 These patients also need dextrocardia from erroneously reversed limb- careful imaging, consideration of other associ- electrode placement, which shows normal R- ated congenital cardiac abnormalities, and de-
wave progression from V1 to V6 while showing tailed planning before cardiac surgery, includ- similar features to those seen in dextrocardia ing coronary artery bypass grafting.9 in the limb leads.2 In right-sided hookup, the Patients with dextrocardia may present limb electrodes are reversed, and the chest with cardiac symptoms localized to the right electrodes are recorded from the right precor- side of the body and have confusing clinical dium. and diagnostic fi ndings. Keeping dextrocardia and other such anomalies in mind can prevent ■ CORONARY INTERVENTIONS delay in appropriately directed interventions. REQUIRE SPECIAL CONSIDERATION In a patient such as ours, the heart on the right In patients with dextrocardia, coronary inter- side of the chest may indeed be “right.” Still, ventions can be challenging because of the diagnostic tests to look for disorders encoun- mirror-image position of the coronary ostia tered with dextrocardia may be necessary. ■ ■ REFERENCES 1. Perloff JK. The cardiac malpositions. Am J Cardiol 2011; Turk J Gastroenterol 2003; 14:151–155. 108:1352–1361. 7. Kuehl KS, Loffredo C. Risk factors for heart disease 2. Tanawuttiwat T, Vasaiwala S, Dia M. ECG image of the associated with abnormal sidedness. Teratology 2002; month. Mirror mirror. Am J Med 2010; 123:34–36. 66:242–248. 3. Douard R, Feldman A, Bargy F, Loric S, Delmas V. Anoma- 8. Aksoy S, Cam N, Gurkan U, Altay S, Bozbay M, Agirbasli lies of lateralization in man: a case of total situs inversus. M. Primary percutaneous intervention: for acute myocar- Surg Radiol Anat 2000; 22:293–297. dial infarction in a patient with dextrocardia and situs inversus. Tex Heart Inst J 2012; 39:140–141. 4. Maldjian PD, Saric M. Approach to dextrocardia in adults: 9. Murtuza B, Gupta P, Goli G, Lall KS. Coronary revasculariza- review. AJR Am J Roentgenol 2007; 188(suppl 6):S39–S49. tion in adults with dextrocardia: surgical implications of 5. Gindes L, Hegesh J, Barkai G, Jacobson JM, Achiron R. Iso- the anatomic variants. Tex Heart Inst J 2010; 37:633–640. lated levocardia: prenatal diagnosis, clinical importance, and literature review. J Ultrasound Med 2007; 26:361–365. ADDRESS: Prashant Sharma, MD, Department of Hospital 6. Abut E, Arman A, Güveli H, et al. Malposition of internal Internal Medicine, Mayo Clinic, 200 1st St. SW, OL-2, Rochester, organs: a case of situs ambiguous anomaly in an adult. MN 55905; e-mail: [email protected]
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