Ann Thorac Surg 1998;65:1146-1148
© 1998 The Society of Thoracic Surgeons
Case Reports
Right Ventricular Dysplasia May Pose Risk of Ventricular Rupture After Cardiac Operations
Sheryl L. Asplund, MDa,
Paul C. Taylor, MDb,
Norman B. Ratliff, MDa
a Department of Anatomic Pathology and Laboratory Medicine, The Cleveland Clinic Foundation, Cleveland, Ohio, USA
b Department of Thoracic and Cardiovascular Surgery, The Cleveland Clinic Foundation, Cleveland, Ohio, USA
Accepted for publication November 13, 1997.
Address reprint requests to Dr Asplund, Department of Anatomic Pathology, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195
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Abstract
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We report the second case of rupture of the right ventricle secondary to right ventricular dysplasia after an otherwise uneventful coronary bypass graft operation. This suggests that right ventricular dysplasia may be a risk factor for ventricular rupture after cardiac operations.
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Introduction
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Right ventricular dysplasia (RVD) is uncommon, characterized by partial replacement of the right ventricle with fat. Complications include arrhythmias, sudden death, and ventricular rupture [1–8]. A single case of RVD with ventricular rupture in a postoperative cardiac patient has been reported [3]. We report the second case and suggest that RVD is a risk factor for cardiac rupture after cardiac operations.
A slightly obese 52-year-old man with hypercholesterolemia and no cardiac history presented with unremitting chest pain. Cardiac enzyme levels and electrocardiogram were consistent with inferolateral myocardial infarction. Cardiac catheterization revealed severe four-vessel disease without dyskinesis; quadruple coronary artery bypass grafting was performed 3 days later. He did not experience arrhythmia, altered contractility, or difficulty during bypass withdrawal. The right ventricle was not traumatized. Recovery was uneventful, with discharge 5 days postoperatively. On the second day at home, he awoke with extreme chest pain. He walked to the bathroom unassisted and seated himself on the commode. The chest pain continued; his wife noted increasing pallor. The patient asked for help, slumped forward, and fell to the floor. On arrival, paramedics found the patient unconscious and apneic, with an idioventricular rhythm of 20 beats/min. In spite of resuscitative efforts, the patient never regained a normal pulse and was pronounced dead on arrival at the local emergency room. Permission for autopsy was granted.
At autopsy, 750 mL of clotted blood was adherent to the anterior surface of the heart and extended into the opened pericardial sac, across the mediastinal soft tissues, and into the left pleural space. One thousand two hundred milliliters of bloody fluid was in the left pleural cavity. The heart weighed 410 g and had normally configured chambers and a codominant coronary circulation with severe coronary atherosclerosis. All grafts were patent, with intact anastomoses and patent distal native vessels. The midanterior right ventricular wall had a slightly irregular, vertical, 1.2-cm transmural tear (Fig 1). Cross-section of this area showed extreme thinning of the myocardium with focal paper-thin areas. Neither the posterior right ventricle nor the left ventricle had such changes. Multifocal organizing and organized myocardial infarcts involved the left ventricle and interventricular septum.
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Fig 1. Gross cross-sections through the tear in the anterior right ventricle. Note the thin layer of myocardium between the trabeculae and epicardial adipose tissue. Arrows indicate the tear. The inset is an enlargement of the irregular tear.
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Microscopic examination of the anterior right ventricle revealed extensive transmural fatty infiltration (Fig 2), focal decrease in the number of myocytes, foci of fibrosis, and myocyte disarray near the tear(Figs 2, 3). Continuous, irregular islands of adipose tissue without muscle fibers extended from the endocardium to epicardium. These changes were limited to the anterior right ventricle. Mild, focal lymphocytic myocarditis was also present but not in the vicinity of the tear. In the tear itself, only disrupted myocardium and acute dissection channels were found. Multifocal myocardial infarcts were confined to the left ventricle and interventricular septum. No other autopsy findings were remarkable.
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Fig 2. Histologic section of the anterior right ventricle. Myocyte disarray, intermyocyte fibrous tissue, and adipose tissue are evident. (Movat’s pentachrome stain; x100 before 52% reduction.)
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Fig 3. Histologic section of the right ventricle. The band of myocardium between the right ventricular cavity and the epicardial fat is thin and contains adipose tissue and fibrous tissue between bundles of myocytes. (Movat’s pentachrome stain; x100 before 52% reduction.)
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Comment
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The phenomenon of fatty infiltration of the myocardium, usually in the right ventricle, has been recognized since the early 1900s [1]. Various terms for this infiltration include RVD, arrhythmogenic ventricular dysplasia [1, 2], or simply fatty infiltration [3]. Presenting features include sudden death, arrhythmias, rarely left or right ventricular rupture, cardiomegaly, and congestive heart failure [4]. Most patients lack symptoms and have normal electrocardiographic and angiographic studies, with RVD discovered at autopsy or during a cardiac operation for unrelated disease [5].
The gross features vary from visible foci of fat in the myocardium to extreme thinning without grossly evident adipose tissue and rarely focal aneurysmal dilatation [1, 2]. As in our case, infiltration and replacement of myocardium by mature adipose tissue is consistently seen, often with associated foci of fibrosis; focal myocyte disarray and lymphocytic myocarditis also have been reported [1–6].
The cause of RVD is not known. A hereditary tendency has been identified in a few families with histories of sudden death and other cardiac diseases [2, 4, 7]. The male-to-female ratio is 2.7:1 [2, 4]. Pathogenetically, the fat may arise from septal deposits, congenital lack of myocardium with secondary infiltration, an age-related change, or secondary to an indolent myocarditis [2, 8].
In the only other reported case of RVD and postsurgical rupture, the findings were nearly identical to ours [3]. An intact pericardium may buttress the weak areas of the right ventricle, and loss of an intact pericardium may contribute to rupture. We cannot exclude rupture of the right ventricle during resuscitation, but then the collapse requires an explanation.
In conclusion, we report the second postoperative case, and the fifth case overall, of a ruptured ventricle secondary to RVD. This case suggests that RVD may be a risk factor for ventricular rupture after uneventful cardiac operations.
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References
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- Borkowski P., Cespedes E., Agatston A., Robinson M. Left ventricle rupture through an area of fatty infiltration: case report and review of the literature. Cardiovasc Pathol 1996;5:85-88.
- Pinamonti B., Di Lenarda A., Sinagra G., et al. Long-term evolution of right ventricular dysplasia-cardiomyopathy. Am Heart J 1995;129:412-415.[Medline]
- Barnard S., Kitching P., Kulatilake E. Right ventricular rupture after coronary surgery. Cardiovasc Surg 1994;2:723-734.[Medline]
- Marcus F., Fontaine G., Guiraudon G., et al. Right ventricular dysplasia: a report of 24 adult cases. Circulation 1982;65:384-398.[Abstract/Free Full Text]
- Chauhan A., More R.S. Arrhythmogenic right ventricular dysplasia. Int J Cardiol 1996;56:107-112.[Medline]
- Pomerance A., Davies M. Fatty infiltration of the heart. The Pathology of the heart. Oxford: Blackwell Scientific, 1975:56-57.
- Marcus F.I., Fontaine G. Arrhythmogenic right ventricular dysplasia/cardiomyopathy: a review. PACE 1995;18:1298-1313.
- Kusano J., Shiraishi T., Morimoto R., Haba K., Yatanis R. Cardiac rupture due to severe fatty infiltration in the right ventricular wall. J Forensic Sci 1991;36:1246-1250.[Medline]
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Abstract
Introduction
