This patient most likely has constrictive pericarditis, as a result of prior cardiac surgery, as evidenced by a positive Kussmaul's sign (raised JVP on inspiration), increased JVP, and a pericardial knock.
Common causes of constrictive pericarditis include radiation therapy, viral pericarditis, and cardiac surgery. Hepatomegaly and other signs of right heart failure, ascites, fatigue, and peripheral edema may also be present. Since this patient is post-MI, it raises concerns for tamponade that may require drainage, but is unlikely as the average time of presentation is 10 days post-CABG (Kuvin et al.). The onset is unpredictable in most cases, with early intervention for symptomatic relief. Severe cases require a partial or complete pericardiectomy.
Tingle et al. discuss acute pericarditis. They report that pericarditis is predominantly caused by a viral infection, though may also be the result of diseases, drugs, invasive cardiothoracic procedures, and chest trauma. Classic presentation is an abrupt-onset of chest pain, the presence of a pericardial friction rub, and changes on electrocardiography suggest acute pericarditis (PR-segment depression and upwardly concave ST-segment elevation). The pericardial friction rub is very specific but has poor sensitivity. Echocardiography is recommended to confirm the diagnosis and exclude the presence of tamponade.
Gaudino et al. discuss constrictive pericarditis, which may develop as a midterm or late complication of cardiac surgery. The post-surgical causes of constrictive pericarditis are not known. The presentation can be nonspecific and should be suspected any time during post-operative follow-up. Transthoracic echocardiography may not be suggestive of the diagnosis.
Illustration A shows a thickened pericardium as seen with constrictive pericarditis on CT.
Illustration B shows the classic acute pericarditis finding on EKG. Note the diffuse ST elevations in all leads. Of note, this may not be present with constrictive pericarditis.
Answer 2: Patients with an interventricular septum perforation present following an MI, but would have a holosystolic murmur, not a knock. Additionally, the presentation would be much more acute.
Answer 3: Patients with a ventricular wall perforation present following an MI but would have tamponade. Additionally, the presentation would be much more acute.
Answer 4: Viral pericarditis can cause constrictive pericarditis as sequela; however, the patient's symptoms and history are more consistent with constrictive pericarditis.
Answer 5: A right ventricular infarction can cause right sided heart failure, leading to the ascites, hepatomegaly, and edema seen in this patient, but a pericardial knock and Kussmaul's sign would not be expected.
Tingle LE, Molina D, Calvert CW. Acute pericarditis. Am Fam Physician. 2007 Nov 15;76(10):1509-14.
PMID:18052017 (Link to Abstract)
Gaudino M, Anselmi A, Pavone N, Massetti M. Constrictive pericarditis after cardiac surgery. Ann Thorac Surg. 2013 Feb;95(2):731-6. doi: 10.1016/j.athoracsur.2012.08.059. Epub 2012 Dec 22.
PMID:23266135 (Link to Abstract)
Kuvin JT, Harati NA, Pandian NG, Bojar RM, Khabbaz KR. Postoperative cardiac tamponade in the modern surgical era. Ann Thorac Surg. 2002 Oct;74(4):1148-53.
PMID:12400760 (Link to Abstract)