Segmental Diastolic Compression of Venous and Arterial Conduits Post Coronary Artery Bypass Surgery

ABSTRACT: In a case of constrictive pericarditis post coronary artery bypass surgery we describe the diastolic compression of venous and arterial conduits and the timing of compression, as demonstrated during angiography, before and after pericardiectomy. In conclusion, angiographic demonstration of conduit compression is only suggestive of constriction, and consideration of the timing of compression during diastole should be a more specific sign.

J INVASIVE CARDIOL 2010;22:E150–E152

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Any process affecting the pericardium (incision, inflammation or calcification) can lead to local or global reduced pericardial compliance. As the myocardium relaxes and fills during diastole, a portion of an epicardial coronary artery could become compressed between the myocardium and pericardium. Compression of the native coronary arteries has been described in one case of constrictive pericarditis¹ but also in two cases of aortic insufficiency,² in one case of localized left ventricular dysfunction,³ and in one case post heart transplantation.⁴ Diastolic compression of venous grafts has been reported, but not related to constrictive pericarditis.^5,6 The case presented here demonstrates for the first time diastolic compression of a venous and an arterial conduit associated with constrictive pericarditis and the angiographic result of pericardiectomy. In addition, the importance of the timing of the compression during diastole in the interpretation of the findings is presented. Case Report. The patient, a 56-year-old male, developed dyspnea, ascites and peripheral edema with no symptoms of angina over a period of 2 years, after a coronary artery bypass graft (CABG) procedure. Six months after his operation he underwent coronary angiography performed to investigate symptoms of dyspnea. The angiogram demonstrated a patent left anterior internal thoracic artery (LITA) to the left anterior descending artery, a patent vein graft to a ramus branch and a patent vein graft to the right coronary artery. Angioplasty was performed for moderate left main disease with a Cypher stent (Cordis Corp., Miami Lakes, Florida) deployed across the ostium of the left anterior descending artery to the circumflex artery. The patient continued to experience worsening of his symptoms with increasing ascites and peripheral edema. The diagnosis of constrictive pericarditis was entertained and right and left catheterization, coronary angiography and left ventriculography were performed. The simultaneously recorded pressures from the right and left ventricles showed that the elevated diastolic pressures were almost equal and that there was an out-of-phase respiratory variation between the two pressure tracings (Figure 1). The coronary angiogram demonstrated end-diastolic compression of the saphenous vein graft (SVG) to the right coronary artery against the inferior wall (Figure 2) and mid- and end-diastolic compression of the left thoracic artery (LITA) as it entered the pericardial space (Figure 3). Another SVG to the diagonal did not seem to be compressed. The left ventricle was normal in size with good systolic function and no areas with abnormal motion. The patient underwent successful partial pericardiectomy, sparing the part overlying the LITA, with complete symptom resolution. Two years after the pericardiectomy he developed angina and had a coronary angiogram which revealed occlusion of the SVG to the diagonal, but no longer showed compression of the SVG to the right coronary artery (Figure 4). The compression of the LITA was now limited to end-diastole (Figure 5). The simultaneous recording of the right and left ventricular pressures did not demonstrate constrictive physiology. The left ventricular pressure was 104/8/21 mmHg and the right ventricular pressure was 32/2/6 mmHg. Discussion. The finding of segmental diastolic coronary artery compression of native coronary arteries related to constriction has been described,¹ but has rarely been reported. It is of interest that in constrictive pericarditis, no significant change in the diameter of the epicardial coronary arteries during the heart cycle was found by quantitave analysis, suggesting that epicardial arteries, due to epicardial inflammation, may become noncompliant.⁷ That the phenomenon of segmental diastolic coronary artery compression is primarily dependent on local factors is suggested by reports of coronary artery diastolic compression in patients with dilated left ventricles or previous cardiac surgery with a normal left ventricle and no evidence of constriction.^2–4 It is of interest that diastolic compression of venous and arterial conduits has not been described in association with constrictive pericarditis. The two known reports of diastolic SVG compression were associated with severe left ventricular dysfunction and no evidence of constriction.^5,6 In the present case we demonstrate that pericardiectomy relieves the diastolic compression of venous and arterial conduits that may be present in constriction. This seems to be a regional phenomenon as demonstrated by the segmental nature of the compression and persistence of the compression over the LITA, where the pericardium was not dissected away; whether the compression will begin early or late in diastole will depend on the intraventricular pressures and the compliance of the overlying pericardium. Following the pericardiectomy and the normalization of mid-diastolic pressures the compression of the LITA moved later at end-diastole. In contrast complete removal of the pericardium over the area of the venous graft compression completely relieved this effect. The physiologic effect of the compression was not studied in our patient. In a previous report, diastolic compression of a coronary artery with objective evidence of ischemia was managed with deployment of a stent.⁴Conclusion. Diastolic conduit compression can be a sign of constriction and should be looked for in the evaluation of patients post CABG. The diastolic timing of compression is suggestive of the level of diastolic pressures and may be a specific sign of constriction.

References

1. Goldberg E, Stein J, Berger M, Berdoff RL. Diastolic segmental coronary artery obliteration in constrictive pericarditis. Cathet Cardiovasc Diagn 1981;7:197–202. 2. Angelini P, Leachman RD, Autrey A. Atypical phasic coronary artery narrowing. Cathet Cardiovasc Diagn 1986;12:39–43. 3. Oteo J F, Ugartet M. Images in cardiology. Heart 2001;85:336. 4. Garg RK, Anderson AS, Jolly N. Diastolic coronary artery compression in a cardiac transplant recipient: Treatment with a stent. Cathet Cardiovasc Interv 2005;65:271–275. 5. Chokshi KS, Meyers SN. Diastolic segmental compression of saphenous vein bypass graft. Am Heart J 1989;118:402–04. 6. Christophides TH, Georgiou G, Yiangou K. Angiographic segmental narrowing of a saphenous vein bypass graft during diastole. J Invasive Cardiol 2009;21:E101–E102 7. Akasaka T, Yoshida K, Yamamuro A, et al. Phasic coronary flow characteristics in patients with constrictive pericarditis: Comparison with restrictive cardiomyopathy. Circulation 1997;96:1874–1881.

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From the Cardiology Clinic, AHEPA University Hospital, Aristotelion University, Thessaloniki, Greece and Cardiothoracic Surgery, Aristotelion University, Thessaloniki, Greece. The authors report no conflicts of interest regarding the content herein. Manuscript submitted November 6, 2009, provisional acceptance given January 11, 2010, final version accepted February 2, 2010. Address for correspondence: Stavros Hadjimiltiades, MD, A’ Cardiology Clinic, AHEPA University Hospital, Stilponos Kyriakide 1, Thessaloniki, Greece. E-mail: stavros@mail.otenet.gr