Management of Challenging Cardiopulmonary Bypass Separation.

SEPARATION from cardiopulmonary bypass (CPB) after cardiac surgery is a progressive transition from full mechanical circulatory and respiratory support to spontaneous mechanical activity of the lungs and heart. During the separation phase, measurements of cardiac performance with transesophageal echocardiography (TEE) provide the rationale behind the diagnostic and therapeutic decision-making process. In many cases, it is possible to predict a complex separation from CPB, such as when there is known preoperative left or right ventricular dysfunction, bleeding, hypovolemia, vasoplegia, pulmonary hypertension, or owing to technical complications related to the surgery. Prompt diagnosis and therapeutic decisions regarding mechanical or pharmacologic support have to be made within a few minutes. In fact, a complex separation from CPB if not adequately treated leads to a poor outcome in the vast majority of cases. Unfortunately, no specific criteria defining complex separation from CPB and no management guidelines for these patients currently exist. Taking into account the above considerations, the aim of the present review is to describe the most common scenarios associated with a complex CPB separation and to suggest strategies, pharmacologic agents, and para-corporeal mechanical devices that can be adopted to manage patients with complex separation from CPB. The routine management strategies of complex CPB separation of 17 large cardiac centers from 14 countries in 5 continents will also be described.

Relationship between QT dispersion and the incidence of early ventricular arrhythmias in patients with acute myocardial infarction.

There is controversy about the influence of QT dispersion on the incidence of early ventricular arrhythmias in patients with acute myocardial infarction (AMI). The QT and QTc dispersion (QTd, QTcd) between two groups of patients with AMI were compared: 39 patients with early sustained ventricular tachycardia or ventricular fibrillation (VT/VF) and 40 patients without such arrhythmias. QTd and QTcd were calculated from the admission and predischarge ECG, expressed as the difference between the maximum and minimum QT and QTc interval in 12 leads. The coefficient of variability was also calculated (VQT, VQTc). Groups did not differ significantly in age, incidence of previous infarction, Killip class, electrolyte status, infarct location, expected and final ECG infarct size, enzymatic infarct size, thrombolytic treatment and reperfusion rate, i.e., in variables that could influence the VT/VF occurrence. On admission, patients with VT/VF had significantly greater QTd (77+/-23 vs 53+/-27 ms, P<0.001) and QTcd (90+/-29 vs 62+/-28 ms, P<0.001); VQT and VQTc were also significantly higher. Although similar differences existed on predischarge ECG, they were smaller. The results indicate that QT dispersion varies during the illness, and that measurements of QT dispersion could be helpful in predicting serious ventricular arrhythmias.