The right ventricular annular velocity reduction caused by coronary artery bypass graft surgery occurs at the moment of pericardial incision

Abstract

BackgroundRight 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.MethodTransthoracic echocardiography was conducted in 33 patients before and after elective coronary artery bypass graft. In an intensively monitored cohort of 9 patients, we also monitored RV function intraoperatively using serial pulsed wave tissue Doppler (PW TD) transesophageal echocardiography.ResultsThere 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.ConclusionsMinute-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.

Effect of pericardial repair after aortic valve replacement on septal and right ventricular function

“…Post operative data show a clear evidence for reversed septal motion away from the LV cavity together with a fall in all RV conventional functional measurements; long axis amplitude of motion, its systolic and diastolic velocities, and none of them fully recovered up till 6 months after surgery. These findings are in agreement with other studies which showed similar drop in RV long amplitude not only with AVR but also with other surgical procedures which involve the need for cardiopulmonary bypass circulation, particularly in coronary artery by-pass surgery [3,4,[16][17][18][19]. No convincing explanation as to why the septum reverses after bypass surgery has yet been established.…”

Novel Approach to Three-Dimensional Echocardiographic Quantification of Right Ventricular Volumes and Function from Focused Views

“…It has been previously established that under certain conditions, such as after cardiac surgery (in the absence of marked septal shift), the commonly used indices of longitudinal RV function (i.e., tricuspid annular plane systolic excursion and S wave), are generally reduced and no longer accurately represent overall RV performance. [31][32][33] In these situations, RV EF is a valuable clinical tool to assess RV function, which until now could be measured only in patients with highquality ultrasound images.…”

Incremental Value of the Preoperative Echocardiogram to Predict Mortality and Major Morbidity in Coronary Artery Bypass Surgery

“…Two of the predominant disturbances are (1) altered RV contraction and relaxation observed at the time of pericardial opening, 35 and (2) increased LV stiffness attributable to myocardial edema and extrinsic compressive forces. [36][37][38] Thus, given the expected decline in RV performance and LV stiffness after CABG, patients with preoperative findings of abnormal RV performance or LV stiffness (severe diastolic dysfunction) are at a clear disadvantage.…”