Diagnostic value of the water bottle-shaped heart as a marker of rheumatic giant left atrium
L H Adrian, C R SanjayaAbstract
Background
Giant left atrium (GLA), mostly secondary to rheumatic heart disease, is extremely rare in the current era, but still prevalent in the developing countries. One of the common findings to support GLA is the water bottle-shaped heart (WBH) shown in the chest radiograph (CXR). However, it frequently provides a clue to massive pericardial effusion (PE) or dilated cardiomyopathy (DCM), while its relation to the diagnosis of rheumatic GLA has rarely been investigated.
Purpose
To evaluate the diagnostic value of water bottle-shaped heart to support the diagnosis of rheumatic giant left atrium.
Methods
In this prospective observational study, we included 127 patients who presented with WBH and CTR≥80% on the chest radiograph (CXR), from Feb 1, 2022 to Jan 31, 2025. The CXR signs suggestive of LA enlargement, echocardiography and CT thorax with contrast parameters were assessed. Rheumatic GLA was defined as an anteroposterior LA diameter of >65mm or a LAVI >250 mL/m2 with confirmed rheumatic valve disease etiology. We used multivariable logistic regression to investigate the association between variables and performed receiver operating characteristic (ROC) curve analysis to ascertain their diagnostic values for rheumatic GLA.
Results
Of the 127 patients (age 45.9±11.4 years,75.4% female), splaying of carina ≥120° was seen in 31.5%, walking man sign in 28.3%, third mogul sign in 45.6%, and double density sign in 55.9%. The diagnoses of rheumatic GLA, DCM, and massive PE were confirmed in 31.5%, 33.9%, and 34.6% of the participants, respectively. The third mogul and double density signs were significant for DCM according to univariate but not to multivariate analysis. None of the CXR signs were significantly associated with massive PE diagnosis. Only rheumatic GLA was significant both for splaying of carina≥120° (p<0.001) and walking man sign (p=0.045) by multivariate analysis. The best cut-off point of splaying of carina was 120° for rheumatic GLA (accuracy 0.912 [AUC 95% CI 0.842–0.983], sensitivity 82.5%, specificity 98%, p<0.001), while walking man sign was significant for detecting rheumatic GLA with accuracy 0.876 (AUC 95% CI 0.796–0.956), sensitivity 77.5%, and specificity 97% (p<0.001).
Conclusion
Rheumatic GLA is the most significant diagnosis for the presence of widened carinal angle ≥120° and walking-man sign on the CXR in patients with water bottle-shaped heart.Analysis between CXR signs and diagnosisFor image description, please refer to the figure legend and surrounding text.CXR signs performance for rheumatic GLAFor image description, please refer to the figure legend and surrounding text.