Assessment Of Right Ventricular Function In Patients Undergoing Coronary Artery Bypass Graft In Assiut University

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Detailed Description

Right ventricular (RV) dysfunction is a major risk factor in coronary artery disease (CAD) and patient undergoing revascularization with this combination , incidence of RV dysfunction is reported in about 20% cases of CAD. RV dysfunction is a possible cause of cardiac failure after cardiac surgery and has a high mortality rate. RV dysfunction is a recognized cause of hypotension early after coronary artery bypass graft surgery (CABG) A decrease in RV function is an event known to occur after CABG. Right ventricular dysfunction can be seen during and immediately after cardiac surgery. Although the mechanism of this phenomenon is not well understood, cardiopulmonary bypass, perioperative myocardial ischemia, intraoperative myocardial damage, cardioplegia, and pericardial disruption or adhesion have been suggested as probable causes. Major reasons for complications of cardiac surgery are the need for hypothermic cardiac arrest, aortic cross clamping, and exposure to a cardiopulmonary bypass circuit. It has been postulated that avoidance of these factors by performing off-pump coronary artery bypass (OPCAB) surgery might reduce perioperative morbidity and improve outcome. Recently, the portion of coronary artery bypass grafting on the beating heart without the use of cardiopulmonary bypass (CPB) has been expanded in cardiac surgery as a result of awareness of the damaging effect of CPB Whether OPCAB surgery can fulfill these expectations, or to which degree, is yet unclear. A few studies on hemodynamic alternations associated with OPCAB reported that reduced functions of both ventricles during coronary artery anastomosis are the main mechanism of hemodynamic derangements and especially, impaired diastolic function of the right ventricle (RV) plays an important role However, clinical studies evaluating the change in RV function in patients with ischemic heart disease are very rare. It is reported that the major cause of hemodynamic changes during OPCAB was disturbed diastolic filling of the RV through the measurement of chamber pressures or monitoring of echocardiography. There was no significant change in the RVEF and cardiac index during anastomosis of the left anterior descending artery and right coronary artery. However, the significantly reduced RVEF accompanied by an increase in RV afterload and decrease in the CO was observed during anastomosis of the obtuse marginal (OM) artery. RV volumes did not significantly change during anastomoses, though the right atrial pressure increased during anastomoses of all coronary arteries. The displacement of beating heart for positioning during anastomosis of the graft to OM artery caused significant derangement of RV function and decrease in CO.

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