sexta-feira, fevereiro 26, 2010
A pericárdio dependência do ventrículo direito
The right ventricular annular velocity reduction caused by coronary artery bypass graft surgery occurs at the moment of pericardial incision
Unsworth, Beth BSca; Casula, Roberto P. MD, FRCS, FECTSb; Kyriacou, Andreas A. MBChB, MRCPa; Yadav, Hemang MA, MBBSa; Chukwuemeka, Andrew LLB, MD, FRCSa; Cherian, Ashok MDb; Stanbridge, Rex de Lisle MD, FRCSb; Athanasiou, Thanos MD, PhD, FETCSa; Mayet, Jamil MD, FRCPa; Francis, Darrel P. MA, MD, FRCPa
American Heart Journal
Issue: Volume 159(2), February 2010, p 314–322
Background: Right ventricular (RV) long-axis function is known to be depressed after cardiac surgery, but the mechanism is not known. We hypothesized that intraoperative transesophageal echocardiography could pinpoint the time at which this happens to help narrow the range of plausible mechanisms.
Results: There was no significant difference in myocardial velocities from the onset of the operation up to the beginning of pericardial incision, change in RV PW TD S' velocities 3% ± 2% (P = not significant).
Within the first 3 minutes of opening the pericardium, RV PW TD S' velocities had reduced by 43% ± 17% (P < .001). At 5 minutes postpericardial incision, 2 minutes later, the velocities had more than halved, by 54% ± 11% (P < .0001). Velocities thereafter remained depressed throughout the operation, with final intraoperative S' reduction being 61% ± 11% (P < .0001).
One month after surgery, in the full 33-patient cohort, transthoracic echocardiogram data showed a 55% ± 12% (P < .0001) reduction in RV S' velocities compared with preoperative values.
Conclusions: Minute-by-minute monitoring during cardiac surgery reveals that, virtually, all the losses in RV systolic velocity occurs within the first 3 minutes after pericardial incision. Right ventricular long-axis reduction during coronary bypass surgery results not from cardiopulmonary bypass but rather from pericardial incision.
Trabalho brilhante feito em Londres com transesofágico durante a cirurgia de revascularização.
60% da contração do VD é no eixo longo, a mesma medida no estudo.Qual a participação do septo nessa contração e, finalmente, o que o pericárdio têm a ver com a contração do ventrículo direito são perguntas a serem respondidas.