Introduction
Dextrocardia with situs inversus, also known as situs inversus totalis, is a rare congenital condition where the major visceral organs are mirrored from their normal positions. The heart is located on the right side of the thoracic cavity instead of the left, and other organs, such as the liver, spleen, stomach and intestines, are also reversed. This condition occurs in ~1 in 10,000 live births (1). The exact cause of dextrocardia with situs inversus is not fully understood; however, it is believed to involve a combination of genetic and environmental factors. Situs inversus is often inherited in an autosomal recessive manner, meaning both parents must carry a copy of the mutated gene to pass it on to their child (2). Specific genes associated with laterality defects, such as zinc finger protein of the cerebellum 3, located on the X chromosome (Xq26); it encodes a transcription factor critical for early embryonic patterning and regulates signaling pathways (notably NODAL pathway) that establish the left-right body axis. Dynein axonemal heavy chain 5 (DNAH5) encodes a dynein arm motor protein in the outer dynein arm of motile cilia, and DNAH11 is another outer dynein arm heavy chain essential for effective ciliary beating, have been implicated in the development of this condition (3). During normal embryonic development, the organs undergo a complex process of rotation and positioning. In individuals with situs inversus, this process is altered, leading to the mirror-image positioning of the organs. This reversal happens early in embryogenesis, typically within the first few weeks of gestation. People with dextrocardia with situs inversus usually do not have any symptoms directly related to the positioning of their organs and can lead normal, healthy lives (1). However, they may be at an increased risk for certain complications, such as Kartagener syndrome (OMIM: 244400). Approximately 25% of individuals with situs inversus have Kartagener syndrome, which includes chronic sinusitis, bronchiectasis and infertility due to ciliary dysfunction. While most individuals with situs inversus have a structurally normal heart, there is an increased incidence of congenital heart defects, such as transposition of the great arteries, atrial septal defects (OMIM: 600747) or ventricular septal defects (OMIM: 600996), and tetralogy of Fallot (4). Dextrocardia with situs inversus is typically diagnosed through imaging studies, including chest X-ray, which reveals the heart's position on the right side of the chest, echocardiogram, which provides detailed images of the heart's structure and function, and abdominal ultrasound or CT scans, which confirm the reversed positioning of the abdominal organs. Management of dextrocardia with situs inversus focuses on monitoring for and addressing any associated conditions or complications. Regular follow-up with a healthcare provider is essential to ensure any potential issues are identified and treated promptly. The prognosis for individuals with dextrocardia with situs inversus is generally good, especially in the absence of significant congenital heart defects or other associated syndromes (5). With appropriate medical care, most individuals can expect to live a normal lifespan.
Discussion
The present case emphasizes the importance of combining physical examination with electrocardiographic and imaging findings when diagnosing dextrocardia with situs inversus, especially in patients who present with non-specific symptoms. The present patient, a young adult with no known comorbidities, showed normal cardiac anatomy and function despite a complete mirror-image arrangement of the thoracoabdominal organs. The present case highlights the significance of recognizing unique ECG abnormalities that could otherwise lead to misinterpretation and unnecessary testing. Such clinical vigilance is vital to prevent diagnostic errors and overtreatment.
In the present study, differential diagnoses considered at presentation included pneumonia, bronchitis, tuberculosis, congenital heart disease, pericarditis, gastroesophageal reflux disease and cholecystitis. These were excluded based on normal inflammatory markers, negative serology and supportive imaging studies, which confirmed situs inversus totalis with dextrocardia and no structural cardiac defects.
Dextrocardia with situs inversus presents a unique diagnostic challenge due to its frequent association with congenital cardiac anomalies. When dextrocardia is associated with situs solitus, the incidence of notable cardiac defects, such as atrial septal defects, ventricular septal defects and the transposition of the great vessels, is high, reaching 90-95% (6-8). By contrast, patients with situs inversus totalis, as in the present case, often have structurally normal hearts, although other anomalies may still be present.
Associated defects in situs inversus may go beyond the cardiovascular system and include duodenal atresia (OMIM: 223400), asplenism (OMIM: 271400) or polysplenia, ectopic or horseshoe kidneys and various pulmonary abnormalities, such as chronic sinopulmonary infections and bronchiectasis (8). The presence of situs inversus along with primary ciliary dyskinesia (OMIM: 613807) leads to Kartagener syndrome, which is characterized by chronic sinusitis, bronchiectasis and infertility caused by impaired ciliary function (9,10).
The cause of laterality defects such as dextrocardia with situs inversus remains multifactorial. Genetic factors, including mutations in the DNAH5 gene, are essential in disrupting left-right asymmetry during embryogenesis (11). Environmental influences such as maternal diabetes, teratogenic exposure and rare cases of conjoined twinning have also been linked (11,12).
Management requires a multidisciplinary approach tailored to the patient's specific anatomical and functional anomalies. A comprehensive cardiac evaluation using echocardiography and ECG is essential for detecting structural or electrical abnormalities (1,2). Respiratory assessments and physiotherapy become particularly important in patients with suspected or confirmed Kartagener syndrome (9,10).
When surgical intervention is needed, careful attention should be paid to reversed organ orientation to prevent intraoperative errors. Genetic counseling should be provided to affected individuals and their families, especially those planning future pregnancies, to understand hereditary risks and implications (11-13). Advances in diagnostic imaging and genetic testing have greatly improved early detection and enabled personalized treatment strategies.
The present case report highlights the educational importance of recognizing such rare congenital conditions and stresses the need for a high index of suspicion in atypical clinical cases. Early detection, proper referral and structured follow-up are essential for improving outcomes in patients with dextrocardia and situs inversus.