Evan Hall MD, Kanjit Leungsuwan MD, Austin Saugstad DO MBA, Steve Leung MD FACC FASE FSCCT FSCMR
Division of Cardiovascular Medicine, University of Kentucky, Lexington, Kentucky, USA
Clinical History
A 54-year-old male presented to outside facility electrophysiology clinic for evaluation of recurrent symptomatic paroxysmal supraventricular tachycardia (SVT) in the setting of dextrocardia. Apart from the apical impulse being on the right side of the chest and chest wall abnormality, no other notable physical exam abnormalities were noted. Cardiac monitoring confirmed narrow-complex tachycardias (strip from outside facility not provided). Echocardiography, which revealed dextrocardia and suspected right ventricular hypertrophy, raised concern for associated congenital abnormalities. Cardiovascular magnetic resonance (CMR) was ordered for further evaluation.
CMR Findings
CMR was performed on a 1.5T Aera scanner (Siemens Healthineers, Erlangen Germany). Axial localizers demonstrated situs solitus, dextrocardia, and dextroposition (Movie 1). There were atrioventricular and ventriculoarterial concordance {S,D,S} (Movie 2, 3). Biventricular size and function were normal without myocardial scar, significant valvular abnormalities, or evidence of significant intracardiac shunt (Qp:Qs = 1 by phase contrast imaging sequences).
There was no evidence of volume loss of the right lung, space-occupying pathology of the left lung, severe thoracic scoliosis or pectus excavatum to explain the heart position shifting to the right hemithorax. The left chest wall musculature was absent (Movie 1), which in the absence of prior chest wall surgery, was consistent with Poland syndrome.
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| Movie 1. Balanced steady-state free precession (bSSFP) axial stack localizer revealed the absence of left chest wall musculature (both pectoralis major and minor). Within the chest, there was dextrocardia, dextroposition, and thoracic and abdominal situs solitus. There was no signs of volume loss on the right hemithorax or space occupying pathology in the left hemithorax. |
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| Movie 2. Four chamber cine bSSFP highlighted dextrocardia, dextroposition with atrioventricular concordance, and normal biventricular size and function. The left pectoralis musculature was notably absent. |
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| Movie 3. Three chamber cine bSSFP demonstrated ventriculoarterial concordance and no gross mitral or aortic abnormalities. |
Conclusion
This case demonstrates the value of CMR in the approach to a patient with dextrocardia, leading to the rare diagnosis of Poland Syndrome. CMR confirmed situs solitus, dextrocardia, dextroposition {S,D,S} and normal cardiac anatomy and vascular connections, as well as absence of chest wall musculature as an incidental extracardiac finding.
Following CMR, the patient underwent an electrophysiology study with cardiac computed tomography (CT) guidance demonstrating reproducibly induced typical atrioventricular nodal reentrant tachycardia. Radiofrequency ablation of the slow pathway was successfully performed with no further medications or clinical recurrences of SVT. The patient continues to be followed in outside facility cardiology clinic.
Perspective
Abnormal cardiac position including dextrocardia (apex pointing towards the right side of the chest wall) and dextroposition (heart residing in the right hemithorax) are rare. The incidence of dextrocardia is around 1 in 12,000 pregnancies, and prevalence of approximately 0.089 per 1,000 individuals.[1,2] It affects men and women equally.[3] Apart from excluding spurious dextrocardia (in which the mediolateral plane is inadvertently flipped on chest X-ray), the differential diagnoses remain broad. The patient described in this case does not have limb abnormalities, but does demonstrate exam findings consistent with absent chest wall musculature and right-sided point of maximum impulse. By excluding congenital heart diseases by segmental analysis, such as situs inversus (including Kartagener syndrome, a.k.a. primary ciliary dyskinesia, with the triad of situs inversus, sinusitis, and bronchiectasis), transpositions of great vessels, and other heterotaxy syndromes, isolated dextrocardia is diagnosed.
Dextrocardia with situs solitus, D-loop ventricles, and normally related great arteries results from failure of the final leftward shift of the ventricles during embryologic development, termed “dextroversion.[4]” Without acquired interventions such as lung volume reduction surgeries and/or chest wall musculature removal surgeries, two main differential diagnoses remain. Pulmonary abnormalities including loss of right lung volume (hypoplasia or agenesis) and space-occupying lesions in the left lung (emphysema, pneumothorax, pleural effusion, or diaphragmatic hernia), and musculoskeletal abnormalities (severe scoliosis, severe pectus excavatum, and Poland syndrome) are left.
Poland syndrome is a rare congenital condition characterized by hypoplasia of the pectoralis major muscle, first described by Mr. Alfred Poland in 1836.[5-7] Other deformities can include breast bud, nipple-areola complex, upper limb, and surrounding tissues.[6] Dextrocardia is observed in approximately 11.5% of patients with left-sided Poland syndrome, whereas there is no association between more-common right-sided cases and dextrocardia. This suggests mispositioning is more likely due to extrinsic deformities displacing the congenitally normal heart as opposed to intrinsic disease.[8] The prognosis of patients with Poland syndrome largely depends on degree of functional limitations (chest wall or limb involvement) and/or associated impact of cardiac abnormalities. The syndrome itself is not life-limiting in most patients, with the majority of individuals having a normal life expectancy.[5,8] There is no current evidence demonstrating association between Poland syndrome and any particular type of arrhythmias.
Our case demonstrates CMR findings of situs solitus, atrioventricular and ventriculoarterial concordance with normal chamber size and systolic function, and absence of chest wall musculature consistent with previous case reports.[4]
Click here to view the entire CMR on CloudCMR.
References
- Bohun CM, Potts JE, Casey BM, Sandor GG. A population-based study of cardiac malformations and outcomes associated with dextrocardia. Am J Cardiol. 2007 Jul 15;100(2):305-9. doi: 10.1016/j.amjcard.2007.02.095. Epub 2007 May 25. PMID: 17631088.
- Liu Y, Chen S, Zühlke L, Black GC, Choy MK, Li N, Keavney BD. Global birth prevalence of congenital heart defects 1970-2017: updated systematic review and meta-analysis of 260 studies. Int J Epidemiol. 2019 Apr 1;48(2):455-463. doi: 10.1093/ije/dyz009. PMID: 30783674; PMCID: PMC6469300.
- Mozayan C, Levis JT. ECG Diagnosis: Dextrocardia. Perm J. 2019;23:18-244. doi: 10.7812/TPP/18.244. Epub 2019 Aug 15. PMID: 31496498; PMCID: PMC6730946.
- Maldjian PD, Saric M. Approach to dextrocardia in adults: review. AJR Am J Roentgenol. 2007 Jun;188(6 Suppl):S39-49; quiz S35-8. doi: 10.2214/AJR.06.1179. PMID: 17515336.
- Perla G, Mah’moud M, Jackson O, Low DW, Ligh CA. Approach to the Pediatric Poland Syndrome Patient: A 20-Year Academic Experience and Update of the Literature. Ann Plast Surg. 2025 Apr 1;94(4S Suppl 2):S194-S202. doi: 10.1097/SAP.0000000000004320. PMID: 40167071.
- Urschel HC Jr. Poland’s syndrome. Chest Surg Clin N Am. 2000 May;10(2):393-403, viii. PMID: 10803341.
- Poland A. (1841). “Deficiency of the pectoral muscles”. Guy’s Hospital Reports. VI: 191-193. “Plate”. Guys Hosp Rep. 1836.
- Torre M, Baban A, Buluggiu A, Costanzo S, Bricco L, Lerone M, Bianca S, Gatti GL, Sénès FM, Valle M, Calevo MG. Dextrocardia in patients with Poland syndrome: phenotypic characterization provides insight into the pathogenesis. J Thorac Cardiovasc Surg. 2010 May;139(5):1177-82. doi: 10.1016/j.jtcvs.2009.08.024. Epub 2009 Nov 11. PMID: 19909992.
Case Prepared by:
Madhusudan Ganigara, MD
Cases of SCMR, Editorial Board Member
The University of Chicago & Biological Sciences