Preoperative left ventricular energy loss in the operating theater
reflects subjective symptoms in chronic aortic regurgitation
Abstract
Objective: There is currently no subjective, definitive evaluation
method for therapeutic indication other than symptoms in aortic
regurgitation. Energy loss, a novel parameter of cardiac workload, can
be visualized and quantified using echocardiography vector flow mapping.
The purpose of the present study was to evaluate whether energy loss in
patients with chronic aortic regurgitation can quantify their subjective
symptoms more clearly than other conventional metrics. Methods: We
studied 15 patients undergoing elective aortic valve surgery for aortic
regurgitation. We divided the patients into symptomatic and asymptomatic
groups using their admission records. We analyzed the mean energy loss
in one cardiac cycle using transesophageal echocardiography during the
preoperative period. The relationships between symptoms, energy loss,
and other conventional metrics were statistically analyzed. Results:
There were seven and eight patients in the symptomatic and asymptomatic
groups, respectively. The mean energy loss of one cardiac cycle was
higher in the symptomatic group (121 [96 to 184]) than in the
asymptomatic group (87 [80 to 103]) (p=0.040), whereas the diastolic
diameter was higher in the asymptomatic group (65 [59 to 78]) than
in the symptomatic group (57 [51 to 57]) (p=0.040). There was no
significant difference between the symptomatic and asymptomatic groups
in terms of other conventional metrics. Conclusions: An energy loss can
quantify patients’ subjective symptoms more clearly than other
conventional metrics. The small sample size is the primary limitation of
our study, further studies assessing larger cohort of patients are
warranted to validate our findings.