ABSTRACT
BACKGROUND: Atrial fibrillation (AF) remains the most common complication of cardiac surgery. Prophylactic therapies have been studied, but their utility has been limited by the inability to accurately identify patients who will develop this complication. Recent studies have suggested that atrial myolysis and lipofuscin pigmentation are associated with post-coronary artery bypass grafting (CABG) AF. We sought to determine whether there is an association between preoperative atrial histology and subsequent post-CABG AF. METHODS: Samples of right atrial appendage were obtained from 94 patients undergoing CABG. Tissue was formalin fixed and paraffin embedded. Sections 4 mum thick were cut, stained with hematoxylin and eosin, and examined for the following parameters: fibrosis, myolysis, inflammation, nuclear size, pericardial exudates, lipofuscin pigment, arteriolar hypertrophy, contraction banding, mesothelial hyperplasia, and atrial diverticula. Results were graded as absent, mild, moderate, or severe by two independent observers who were blinded to the clinical outcomes. Univariate and multivariate analyses were carried out. RESULTS: Thirty-six (38%) patients developed AF. No correlation was found between the 10 features assessed, including myolysis and lipofuscin pigmentation, and the development of AF. CONCLUSION: Simple morphology of right atrial appendages does not predict the development of postoperative AF.
Subject(s)
Atrial Fibrillation/etiology , Coronary Artery Bypass/adverse effects , Aged , Aged, 80 and over , Atrial Appendage/pathology , Atrial Fibrillation/pathology , Biopsy , Humans , Middle Aged , Risk FactorsABSTRACT
BACKGROUND: The aim of the study was to determine the relationship between the rate of peak early mitral inflow velocity and the peak early diastolic mitral annular tissue velocities in normal controls and to compare them with subjects with diastolic dysfunction. METHODS: The relationship between early passive diastolic transmitral flow and peak early mitral annular velocity in the normal and in diastolic dysfunction was studied. Two groups comprising 22 normal controls and 25 patients with diastolic dysfunction were studied. RESULTS: Compared with the normal group, those with diastolic dysfunction had a lower E/A ratio (0.7 +/- 0.2 vs. 1.9 +/- 0.5, p < 0.001), a higher time-velocity integral of the atrial component (11.7 +/- 3.2 cm vs. 5.5 +/- 2.1 cm, p < 0.0001), a longer isovolumic relaxation time 73 +/- 12 ms vs. 94 +/- 6 ms, p < 0.01 and a lower rate of acceleration of blood across the mitral valve (549.2 +/- 151.9 cm/sec2 vs. 871 +/- 128.1 cm/sec2, p < 0.001). They also had a lower mitral annular relaxation velocity (Ea) (6.08 +/- 1.6 cm/sec vs 12.8 +/- 0.67 cm/sec, p < 0.001), which was positively correlated to the acceleration of early diastolic filling (R = 0.66), p < 0.05. CONCLUSIONS: This investigation provides information on the acceleration of early diastolic filling and its relationship to mitral annular peak tissue velocity (Ea) recorded by Doppler tissue imaging. It supports not only the premise that recoil is an important mechanism for rapid early diastolic filling but also the existence of an early diastolic mechanism in normal.