Asynchronous regional left ventricular ejection following acute coronary artery occlusion: A scintigraphic study in the dog

Background: Off-pump coronary artery bypass grafting (OPCAB) is an alternative to coronary artery revascularization and avoids the complications of cardiopulmonary bypass (CPB). The procedure’s success, however, depends on intraoperative hemodynamic stability. Preoperative cardiac function can predict the tolerance to compromised hemodynamics during cardiac surgery. Inability to manage hypotension and low cardiac output while manipulating the heart is the most frequent cause of intraoperative conversion to CPB. Objective: The authors investigated the effects of the preoperative left ventricular ejection fraction (LVEF) on the success of OPCAB surgery and the relation of intraoperative factors to the success of OPCAB surgery. Material and Methods: Medical records of 284 patients who underwent OPCAB surgery in Ramathibodi Hospital between January 2015 and December 2017 were retrospectively reviewed. Preoperatively, the patients were classified into groups 1 to 4 based on LVEFs of 50% to 70%, 40% to 49%, 30% to 39%, and <30%, respectively. Preoperative characteristics were collected. Intraoperative success of OPCAB surgery, application of inotropes, vasopressor, fluid, and intra-aortic balloon pump (IABP), and post-operative outcomes were analyzed and compared among the four LVEF groups. Results: No significant differences in success of OPCAB surgery emerged among the four groups (p=0.430). Intraoperative requirements of IABP were significantly higher for LVEF <30% patients (p=0.001). In addition, the time to extubation was significantly delayed (p=0.001) and the LVEF <30% patients stayed longer in intensive care unit (ICU) (p=0.002) when compared with the good LVEF patients. There were no significant differences in the operative time, amount of intravenous fluid, blood transfusion requirement, or blood loss among the groups. There were no significant differences in major postoperative morbidities. Conclusion: OPCAB surgery can be performed successfully in patients with severe cardiac dysfunction (LVEF <30%) without significant differences from LVEF ≥30% patients, although the need for an intraoperative IABP device and inotropic drugs for hemodynamic support were greater and the extubation times and ICU stays were longer. Keywords: Coronary artery bypass graft; Left ventricular ejection fraction; Off-pump CABG; OPCAB; Poor cardiac function

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Preventive Effect of Yuzu and Hesperidin on Left Ventricular Remodeling and Dysfunction in Rat Permanent Left Anterior Descending Coronary Artery Occlusion Model

PLoS ONE ◽

10.1371/journal.pone.0110596 ◽

2015 ◽

Vol 10 (1) ◽

pp. e110596 ◽

Cited By ~ 8

Author(s):

Hye Yon Yu ◽

Ji Hun Ahn ◽

Se Won Park ◽

Yi-Sook Jung

Keyword(s):

Coronary Artery ◽

Ventricular Remodeling ◽

Left Ventricular Remodeling ◽

Coronary Artery Occlusion ◽

Artery Occlusion ◽

Left Ventricular ◽

Preventive Effect ◽

Occlusion Model

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Effect of exercise on coronary pressure-flow relationship in hypertrophied left ventricle

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1995.269.1.h271 ◽

1995 ◽

Vol 269 (1) ◽

pp. H271-H281 ◽

Cited By ~ 5

Author(s):

D. J. Duncker ◽

J. Zhang ◽

T. J. Pavek ◽

M. J. Crampton ◽

R. J. Bache

Keyword(s):

Coronary Artery ◽

Myocardial Perfusion ◽

Diastolic Pressure ◽

Coronary Artery Occlusion ◽

Artery Occlusion ◽

Left Ventricular ◽

Back Pressure ◽

Pressure Flow ◽

Pronounced Increase ◽

Coronary Pressure

Left ventricular (LV) hypertrophy (LVH) secondary to chronic pressure overload is associated with increased susceptibility to myocardial hypoperfusion and ischemia during exercise. The present study was performed to determine whether exercise causes alterations in minimum coronary resistance or effective back pressure [coronary pressure at zero flow (Pzf)] that limit maximum myocardial perfusion in the hypertrophied heart. Ascending aortic banding in 7 dogs increased the LV weight-to-body weight ratio to 7.7 +/- 0.3 g/kg compared with 4.6 +/- 0.2 g/kg in 11 normal dogs (P < 0.01). Maximum coronary vasodilation was produced by intracoronary infusion of adenosine. Under resting conditions, the slope of the pressure-flow relationship (conductance) was significantly lower in the LVH animals than in the normal dogs (7.2 +/- 0.8 vs. 11.9 +/- 0.8 x 10(-2) ml.min-1.g-1.mmHg-1; P < 0.01); the slope correlated with the degree of hypertrophy r = 0.74; P < 0.001). The Pzf measured during total coronary artery occlusion (Pzf,measured) was significantly elevated in LVH compared with normal dogs (25.6 +/- 2.2 vs. 13.0 +/- 1.2 mmHg; P < 0.01); Pzf,measured was positively correlated (r = 0.78, P < 0.0005) with LV end-diastolic pressure measured during total coronary artery occlusion (9.0 +/- 1.1 mmHg in normal dogs and 22.2 +/- 3.2 mmHg in LVH dogs; P < 0.01). Graded treadmill exercise to maximum heart rates of 210 +/- 9 and 201 +/- 8 beats/min in normal and LVH animals, respectively, caused similar decreases in the slope of the pressure-flow relationship in LVH (from 7.7 +/- 0.9 to 6.1 +/- 0.8 x 10(-2) ml.min-1.g-1.mmHg-1; P < 0.01) and normal dogs (from 11.9 +/- 0.8 to 10.0 +/- 0.7 x 10(-2) ml.min-1.g-1.mmHg-1; P < 0.01). However, exercise-induced increases in Pzf,measured were significantly greater in the LVH animals (from 25.6 +/- 2.2 to 40.8 +/- 2.1 mmHg; P < 0.01) than in normal animals (from 13.0 +/- 1.2 to 24 +/- 2.1 mmHg; P < 0.01) (P < 0.01 LVH vs. normal). The greater increase in Pzf paralleled a more pronounced increase in LV end-diastolic pressure in the LVH dogs from 22.2 +/- 3.2 to 39.1 +/- 2.7 mmHg) than in normal dogs from 9.0 +/- 1.1 to 14.2 +/- 2.0 mmHg). The results suggest that exaggerated increases in filling pressure during exercise in the hypertrophied left ventricles contributed to impairment of myocardial perfusion during exercise by augmenting the back pressure, which opposes coronary flow.(ABSTRACT TRUNCATED AT 400 WORDS)

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