Isolated Right Ventricular Noncompaction Cardiomyopathy

Figures

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  Figure 1. Cardiac Computed Tomography Angiography of Case 1 (A) Four-chamber view showing prominent hypertrabeculations of the basal-to-apical right ventricular free wall and mid-to-apical right ventricular septum, with a noncompacted-to-compacted myocardial ratio of 5.2, consistent with isolated right ventricular noncompaction. (B to D) Short-axis views further illustrating the extent of right ventricular hypertrabeculation and D-shaped left ventricle. (E) Axial view demonstrating enlargement of the pulmonary artery with slow flow of contrast, suggestive of impending thrombus formation. (F and G) Oblique views revealing a stretched patent foramen ovale, measuring approximately 0.7 × 1.1 cm, with evidence of right-to-left shunting. (H) Coronal lung window shows no signs of interstitial lung disease or pulmonary fibrosis.

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  Figure 2. Cardiac Computed Tomography Angiography of Case 2 (A and B) Two-chamber and short-axis views demonstrating pronounced right ventricular hypertrabeculation in the basal-to-apical right ventricular free wall and septum, with a noncompacted-to-compacted myocardial thickness ratio of >7.0 (2.78:0.38 cm), consistent with isolated right ventricular noncompaction. (C) Coronal view showing irregularity on the esophageal wall. (D) Four-chamber view highlighting the diameter measurements of the right ventricle.

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  Figure 3. Cardiac Computed Tomography Angiography of Case 3 (A) Hypertrabeculations of the basal-to-apical right ventricular free wall and mid-to-apical right ventricular septum, with a noncompacted-to-compacted myocardial ratio of 2.5. (B) Right atrial enlargement (estimated area: 19.5 cm2) with prominent trabeculations along the right atrial wall. (C) The stretched patent foramen ovale (yellow arrow). (D) Axial view demonstrating right atrial and right ventricular enlargement. (E to G) Multiplanar views revealing a calcified thrombus within the main pulmonary artery. (H) Lung window demonstrating no evidence of interstitial lung disease or pulmonary fibrosis. All red arrows (in A, B, and E) are points of partially occluded thrombus in pulmonary artery branches.

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  Figure 4. Proposed Diagnostic Algorithm for Isolated Right Ventricular Noncompaction Using Cardiac Computed Tomography Angiography Proposed diagnostic approach for evaluating suspected iRVNC in patients presenting with right heart failure. Initial assessment begins with transthoracic echocardiography using Jenni's or Stöllberger's criteria to identify suggestive noncompaction features. If findings support iRVNC, ECG-gated cardiac computed tomography angiography is recommended to confirm trabecular quantification, evaluate right heart chamber morphology, and assess for secondary features of pulmonary hypertension, evaluation of chronic thromboembolic pulmonary hypertension, or pulmonary thromboembolism. This combined imaging strategy provides comprehensive anatomical and functional characterization of iRVNC. cCTA = cardiac computed tomography angiography; ECG = electrocardiogram; iRVNC = isolated right ventricular noncompaction; PA = pulmonary artery; PFO = patent foramen ovale; LV = left ventricle; CTEPH = chronic thromboembolic pulmonary hypertension.

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  Visual Summary. 3 Adult Patients With Isolated Right Ventricular Noncompaction Demonstrating Distinct Clinical Phenotypes Cardiac computed tomography angiography confirmed right ventricular hypertrabeculation and quantified noncompacted-to-compacted myocardium ratios in all cases, highlighting the heterogeneous clinical spectrum of isolated right ventricular noncompaction and the diagnostic role of multimodal imaging. cCTA = cardiac computed tomography angiography; CTEPH = chronic thromboembolic pulmonary hypertension; ECG = electrocardiogram; LV = left ventricle; NC:C = noncompacted-to-compacted myocardium ratio; PFO = patent foramen ovale; PH = pulmonary hypertension; RA = right atrium; RV = right ventricle; SVT = supraventricular tachycardia; TAPSE = tricuspid annular plane systolic excursion.