Exposure of the grafting site during off-pump coronary bypass surgery (OPCAB) requires displacement of the heart, resulting in a decreased cardiac index (CI) and mixed venous oxygen saturation 1 2 Although these haemodynamic consequences are usually transient and well tolerated,3 4 haemodynamic collapse unresponsive to corrective measures does occur, requiring emergent cardiopulmonary bypass that is associated with poor prognosis.5 6
Underlying mechanisms for these iatrogenic haemodynamic changes during grafting are mainly ascribed to impaired filling and diastolic dysfunction of the right and left ventricle.1 2 4 7 8 Thus, even with preserved systolic function, patients with diastolic dysfunction would be more prone to undergo significant haemodynamic derangement during grafting, however, evidence to support this hypothesis is lacking.
The ratio of early transmitral flow velocity to early-diastolic velocity of the mitral annulus (E/e’) is an indicator of the diastolic function that correlates well with left ventricular (LV) filling pressure.9 10 In addition, a number of studies have demonstrated increased morbidity, mortality or both in patients with elevated E/e’ value after myocardial infarction.11 12
We therefore evaluated the relationship between preoperative E/e’ value and intraoperative changes of haemodynamic variables and patients’ outcome in patients with preserved systolic LV function undergoing OPCAB, in a prospective observational study.
Continua a leggere l’articolo completo: Relationship between echocardiographic index of ventricular filling pressure and intraoperative haemodynamic changes during off-pump coronary bypass surgery