Refractory Postcardiotomy Right Ventricular Failure Revealing Massive Right Ventricular Lipomatous Replacement

Figure 1. Preoperative Transthoracic and Transesophageal Echocardiograms (A) Apical 4-chamber view demonstrating a nondilated right ventricle, right atrium, left ventricle, and left atrium. (B) Transesophageal echocardiogram showing severe mitral regurgitation due to myxomatous degeneration with posterior leaflet prolapse. LA = left atrium; LV = left ventricle; RA = right atrium; RV = right ventricle.

Figure 2. Cardiac Magnetic Resonance Image Four-chamber cine steady-state free precession view showing normal thickness and function of both ventricles. The right ventricle shows no wall motion abnormalities. Standard cine, T2, and late gadolinium enhancement sequences did not reveal pathological intramyocardial fat; dedicated fat-water separation sequences were not performed. Abbreviations as in Figure 1.

Figure 3. Macroscopic Examination of the Heart (A and B) Cross-sectional views showing abundant adipose tissue (black stars) replacing the right ventricular wall, with very little fat surrounding the left ventricle. Left ventricular hypertrophy is observed, which appears greater than estimated by preoperative imaging tests. Inferior infarction scarring (black arrows) at a more distal level is also documented. (C and D) Longitudinal sections demonstrating right ventricular wall thickening at the expense of fat tissue (black stars), predominantly at the level of the outflow tract. Only a thin layer of myocardium (black arrows) remains intact. PV = pulmonary valve.

Figure 4. Histological Findings (A and B) Hematoxylin and eosin staining reveals a large layer of tissue composed of mature adipocytes (asterisks) starting from the epicardium. Adjacent to the endocardium, there is a thin layer of cardiomyocytes (arrows) with connective tissue and adjacent fatty infiltration. (C and D) In the Masson's trichrome images, a thin layer of myocardium (arrows), with fibrous tissue (blue staining) and adjacent fatty replacement (asterisks) is well demonstrated.

Visual Summary. Overview of the Case MR = mitral regurgitation; MRI = magnetic resonance imaging; RV = right ventricle; VA-ECMO = venoarterial extracorporeal membrane oxygenation; POD = postoperative day.