Gilbert P. Connelly

Right coronary artery stenosis : an independent predictor of atrial fibrillation after coronary artery bypass surgery

OBJECTIVES This study attempted to determine the importance of severe proximal right coronary artery disease as a predictor of atrial fibrillation in patients after coronary artery bypass surgery. BACKGROUND Studies in patients undergoing noncardiac surgery have suggested that ischemia in the right coronary artery distribution is associated with a high incidence of atrial fibrillation. However, the importance of right coronary artery disease as a predictor of atrial fibrillation after bypass surgery is unknown. METHODS The occurrence of sustained postoperative atrial fibrillation was studied prospectively in 168 consecutive patients undergoing coronary artery bypass grafting. Patients were followed up postoperatively until discharge. Severe right coronary artery stenosis was defined as > or = 70% lumen narrowing. RESULTS Of 104 patients with proximal or mid right coronary artery stenosis, 45 (43%) had atrial fibrillation postoperatively compared with 12 (19%) of the 64 patients without significant right coronary disease (p = 0.001). Univariate predictors of atrial fibrillation included right coronary artery stenosis (p = 0.001), advancing age (p = 0.0001) and lack of beta-adrenergic blocking agent therapy after bypass surgery (p = 0.0004). Multivariate adjusted risk of developing atrial fibrillation after bypass surgery increased with the presence of severe right coronary artery disease (odds ratio 3.69, 95% confidence interval [CI] 1.61 to 8.48), advancing age (odds ratio 2.24/10 years, CI 1.48 to 3.41) and male gender (odds ratio 2.36, CI 1.01 to 5.49). The use of beta-blockers postoperatively was associated with a protective effect (odds ratio 0.4, CI 0.17 to 0.80). CONCLUSIONS The presence of severe right coronary artery stenosis is an independent and powerful predictor of atrial fibrillation after coronary artery bypass surgery. In association with age, gender and postoperative beta-blocker therapy, these variables can be used to identify patients at increased risk for developing this arrhythmia.

Effects of isometric exercise on the end-diastolic pressure, volumes, and function of the left ventricle in man.

Changes induced in left ventricular (LV) hemodynamics by isometric exercise were analyzed in 43 patients: 30 with coronary heart disease (CAD), four with noncoronary heart disease, nine normal. Volumes were angiographically determined and correlated with left ventricular end-diastolic pressure (LVEDP) both at rest and during the fifth minute of 30% sustained handgrip (HNG). All normals and eight with CAD improved LV function during HNG. LVEDP decreased or remained constant, end-diastolic volume (EDV) decreased, end-systolic volume (ESV) decreased, as ejection fraction (EF) remained constant. None of these eight CAD cases altered their regional LV contraction pattern during HNG.Twenty-five patients, 21 CAD and four nonCAD, showed diminished LV function during HNG. LVEDP increased, EDV decreased, ESV increased, as EF declined. In these 21 CAD patients, at least one major coronary vessel was narrowed 70% or more and, with but two exceptions, was not supported by adequate collaterals. In 18, new asynergic zones developed in previously normally contracting areas or pre-existing asynergic zones extended during HNG.

Increased left ventricular diastolic chamber stiffness immediately after coronary artery bypass surgery

OBJECTIVES The aim of this study was to assess the incidence and severity of left ventricular diastolic dysfunction immediately after coronary artery bypass surgery by utilizing simultaneous transesophageal echocardiographic and hemodynamic monitoring. BACKGROUND Left ventricular diastolic dysfunction has been documented after coronary bypass surgery, but its measurement has been technically difficult to acquire and limited by dependence on loading conditions. METHODS End-diastolic pressure-area curves were constructed before and immediately after coronary bypass surgery in 20 patients. Transesophageal echocardiographic images at the midpapillary level of the left ventricle and hemodynamic data were recorded. Volume status was manipulated to alter loading conditions, and multiple measurements were taken at each loading condition. RESULTS Diastolic function worsened in all patients, as manifested by a postoperative leftward shift of the end-diastolic pressure-area curve. At a comparable preload, mean end-diastolic area +/- SEM decreased by 15% from 17.6 +/- 0.8 to 14.9 +/- 0.8 cm2 postoperatively (p = 0.0001). CONCLUSIONS Left ventricular diastolic chamber stiffness frequently increases immediately after coronary artery bypass surgery. Simultaneous hemodynamic and transesophageal echocardiographic monitoring, through the construction of end-diastolic pressure-area curves, is a useful method to evaluate diastolic function and guide management after cardiac surgery.

Left ventricular dysfunction during infrarenal abdominal aortic aneurysm repair

BACKGROUND Clinical observations suggest that pulmonary artery occlusion pressure (PAOP) underestimates the resuscitative volumes required prior to release of aortic cross-clamp. METHODS To investigate pressure-volume relationships associated with repair of abdominal aortic aneurysm (AAA), we simultaneously monitored PAOP by pulmonary artery catheter (PAC) and estimated left ventricular (LV) diastolic volume using two-dimensional transesophageal echocardiography (TEE) in 22 patients undergoing AAA repair. Data from PAC monitoring and TEE were collected before, during, and after aortic occlusion. TEE cross-sectional images were obtained at the mid-papillary level. RESULTS Overall, PAOP correlated with left ventricular end-diastolic area (LVEDA), but the correlation was not particularly strong (r = 0.37, P < 0.0001). Even within individual patients, LVEDA varied widely for a given PAOP. The strength of the correlation between PAOP and LVEDA also appeared to deteriorate during the course of surgery. The best correlation was seen prior to aortic cross-clamping (r = 0.50, P < 0.0001), but fell somewhat during aortic cross-clamping (r = 0.41, P < 0.0001), and even further after unclamping (r = 0.25, P = 0.005). CONCLUSION This study demonstrates a relatively weak correlation between PAOP and LVEDA using intraoperative TEE during AAA repair. Furthermore, the strength of the correlation worsened during surgery, particularly after unclamping. Although unclear at this time, this finding may be attributable to changes in LV compliance. We found TEE to be a valuable adjunct in guiding volume resuscitation of patients undergoing AAA repair.

Immediate Effect of Aortic Valve Replacement for Aortic Stenosis on Left Ventricular Diastolic Chamber Stiffness

Diastolic dysfunction is common after coronary artery bypass surgery, and we hypothesized that left ventricular (LV) hypertrophy associated with aortic stenosis may lead to worsening LV diastolic function after aortic valve replacement for aortic stenosis. Transesophageal echocardiographic LV images and simultaneous pulmonary arterial wedge pressures were used to define the LV diastolic pressure cross-sectional area relation before and immediately after aortic valve replacement for aortic stenosis in 14 patients. In all patients, LV diastolic chamber stiffness increased, as evidenced by a leftward shift in the LV diastolic pressure cross-sectional area relation. At comparable LV filling (pulmonary arterial wedge) pressures the mean LV end-diastolic cross-sectional area preoperatively was 17.9 +/- 1.7 cm2, but decreased by 32% after aortic valve replacement to 12.1 +/- 1.2 cm2 (p = 0.0001). In conclusion, after aortic valve replacement, diastolic chamber stiffness increased in all patients.

Directed atraumatic coronary sinus cannulation for retrograde cardioplegia administration

A simple method of coronary sinus cannulation for retrograde cardioplegia administration is described that reduces cardiac manipulation. Intraoperative transesophageal echocardiography is used to direct atraumatic coronary sinus cannulation, confirm the depth of insertion of the cannula tip in relation to the ostium, and reduce overall cannulation time.

Systolic anterior motion of the mitral valve after valve repair without an annular ring

A 78-year-old woman underwent mitral reconstruction, consisting of a quadrangular posterior leaflet resection without a concomitant annular ring, for symptomatic mitral regurgitation. Postoperatively she became hypotensive while being treated with dopamine. Transesophageal echocardiography revealed systolic anterior motion of the mitral valve with significant mitral regurgitation. With discontinuation of the dopamine regimen, institution of phenylephrine administration, and volume loading of the ventricle the systolic anterior motion disappeared as did the mitral regurgitation. The patient recovered uneventfully.