Additional cross-sectional transesophageal echocardiography views improve perioperative right heart assessment.

BACKGROUND: Right heart failure is an important cause of perioperative morbidity and mortality, and transesophageal echocardiography (TEE) is crucial for its diagnosis. However, only four of the 20 cross-sectional views recommended in current guidelines for intraoperative TEE focus on the right heart. This study analyzed whether incorporating additional views into the standard TEE examination improves assessment of the right heart. METHODS: Sixty patients underwent standard TEE examination after induction of anesthesia. In addition, five views focusing on the right heart were acquired. Offline analysis tested: (1) whether the additional TEE views can be acquired as reliably as standard views including parts of the right heart; whether incorporating additional views improves the assessment of (2) eight or more right ventricular wall segments based on a predefined nine-segment model; (3) the tricuspid or pulmonary valve in two or more planes; and (4) transvalvular tricuspid and pulmonary flow in orthograde fashion. RESULTS: Additional views could be imaged as reliably (88%) as standard views (90%). Incorporating some of the additional views allowed the assessment of eight or more right ventricular segments in 59 (98%) versus 18 patients (30%) by the standard views alone, and of the pulmonary valve in two or more planes in 60 (100%) versus 15 patients (25%). Several additional views improved orthograde assessment of transvalvular pulmonary flow, but not of tricuspid flow. CONCLUSIONS: The additional TEE views focusing on the right heart can be acquired as reliably as standard views. Incorporating three of them into the standard TEE examination improves comprehensive assessment of the right heart.

A Swiss anaesthesiology closed claims analysis: report of events in the years 1987-2008.

BACKGROUND AND OBJECTIVE: In 1999, the Swiss Society of Anaesthesiology and Reanimation (SSAR) initiated an analysis of closed malpractice claims filed against anaesthetists in a project intended to improve patient safety. This article discusses the results of a review of closed claims between 1987 and 2008 and filed up to the end of 2009. METHODS: Records of closed claims were provided by Swiss professional medical liability insurance companies and the Office for Extrajudicial Expert Review of the Swiss Medical Association. Data were collected by an onsite reviewer, converted into a standardised format and sent to the SSAR Closed Claims Study Group.Assessment criteria employed by the committee were level of care (standard or substandard); severity of injury; appropriateness of patient information; and consent. RESULTS: The records of 171 events leading to anaesthesia-related injuries were entered into the database. These injuries occurred within the period 1987-2008. The majority of claims (54%) were related to regional anaesthesia, with general anaesthesia accounting for 28% and other anaesthesia-related procedures for 18%. The quality of care was judged by the committee to be substandard in 55% of cases, and liability was accepted in 46% of all claims. Negative outcomes were death in 12% and permanent injury in 63% of the patients. CONCLUSION: The closed claims analysis project enabled the SSAR to identify areas of high medicolegal risks to gain an insight into the causes of infrequent but potentially harmful events leading to anaesthesia-related injuries and, based on these data, to develop preventive strategies.

Feasibility of measuring myocardial performance index of the right ventricle in anesthetized patients.

OBJECTIVE: Myocardial performance index, the sum of the 2 isovolumic times divided by the ejection time, contains information on global systolic and diastolic function. This study was performed to determine the feasibility of right ventricular myocardial performance index measurements if measured by transesophageal echocardiography in patients under general anesthesia and positive-pressure ventilation. DESIGN: A prospective cohort study. SETTING: A tertiary care university hospital. PARTICIPANTS: Twenty patients undergoing elective coronary artery bypass graft surgery. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The feasibility of the right ventricular myocardial performance index measurements was assessed in awake patients by using transthoracic echocardiography and reassessed in the same patients under general anesthesia and positive-pressure ventilation using transesophageal echocardiography. The time from the cessation to the onset of 2 consecutive right ventricular inflows was measured as time A; the time from the onset to the cessation of right ventricular ejection was measured as time B. Myocardial performance index was calculated as follows: (time A-time B)/time B. A first reader independently measured all recordings twice to assess intrareader variability and a second reader once to assess interreader variability. Variability (%) was calculated as the mean absolute difference between 2 readings divided by their mean. The myocardial performance index could be measured for all patients. The point estimates of inter- and intraobserver variability of the right ventricular myocardial performance index measurements were 4.3% to 5% in awake patients and 17.8% to 19.6% in anesthetized patients. CONCLUSIONS: This finding questions the use of right ventricular myocardial performance index measurements in anesthetized patients under positive-pressure ventilation.

Assessment of Left Ventricular Dimensions by Transoesophageal Echocardiography in Patients During Coronary Artery Bypass Surgery.

OBJECTIVE: Normative values of left ventricular (LV) end-diastolic area and diameter (EDA and EDD) for intraoperative transoesophageal echocardiography (TEE) have not been established. We aimed to define the ranges of LV EDA and EDD for intraoperative TEE examinations in patients undergoing coronary artery bypass graft (CABG) surgery. METHODS: A MEDLINE search for studies reporting LV EDA and EDD in CABG patients was performed. Individual-level dataset from 333 anaesthetised and mechanically ventilated patients with preserved LV function (study population) were received from 8 studies. EDA and calculated EDD values in the study population were compared with summary mean EDD values obtained by transthoracic echocardiography (TTE) in 2 studies of 500 awake patients with coronary artery disease (CAD). Further, the influence of prespecified factors on EDD was evaluated through a multivariate regression model. RESULTS: LV EDA and EDD values measured by TEE in anaesthetised CABG patients were 16.7±4.7 cm2 and 4.6±0.6 cm, respectively. EDD values measured by TEE in anaesthetised patients were 10% to 13% less those measured by TTE in 2 studies of awake patients (p<0.001). Body surface area, age and fractional area change but not sex were factors that affected LV EDD. CONCLUSION: LV EDD values measured by intraoperative TEE in anaesthetised and mechanically ventilated CABG patients were 10% to 13% less than those measured by TTE in awake CAD patients. This finding indicates that independent normative values specific for intraoperative TEE should be established for guiding intraoperative clinical decisions.

Accuracy of tissue Doppler estimation of the right atrial pressure in anesthetized, paralyzed, and mechanically ventilated patients.

The ratio of tricuspid peak early inflow velocity to peak early diastolic velocity of the lateral tricuspid annulus (the E/Ea ratio) measured by transthoracic echocardiography has been reported to correlate with right atrial (RA) pressure. In this study, the correlation between the E/Ea ratio and RA pressure was tested in 44 anesthetized, paralyzed, and mechanically ventilated patients by transesophageal echocardiography. Mean RA pressure and the following echocardiographic data were recorded simultaneously: tricuspid peak early inflow velocities by Doppler echocardiography, peak early diastolic velocity of the lateral tricuspid annulus by tissue Doppler imaging, and right ventricular and left ventricular end-diastolic areas. Linear regression did not indicate a correlation between the E/Ea ratio and RA pressure (r = -0.11, p = 0.48) or between the E/Ea ratio and the right or left ventricular end-diastolic area index; it revealed a weak correlation between RA pressure and the inspiratory plateau pressure and body mass index. In conclusion, the E/Ea ratio failed to predict RA pressure or planimetric indexes of ventricular preload in anesthetized, paralyzed, and mechanically ventilated patients. In these patients, RA pressure was largely influenced by extracardiac factors.

Transesophageal Doppler echocardiographic detection of intramyocardial collateral flow to the right coronary artery and changes in the flow to the inferior left ventricular wall immediately after coronary artery bypass grafting.

This study examined the feasibility of Doppler transesophageal echocardiography (TEE) to detect collateral flow to the myocardium supplied by the right coronary artery (RCA) in the inferior left ventricular wall. Forty-four patients who underwent elective coronary artery bypass grafting (CABG) were prospectively studied. Presence of collateral flow to the RCA was diagnosed on preoperative angiography using the Rentrop score and by intraoperative Doppler TEE. Agreement of the 2 methods was analyzed by calculating the kappa coefficient. Collateral flow was present on preoperative angiography in 19 patients and absent in 25 patients. Intraoperative TEE detected collateral flow in the inferior wall in 15 patients (79%) with and 3 patients (12%) without angiographic collaterals, resulting in a kappa coefficient for agreement of 0.67 (95% confidence interval 0.45 to 0.90). Baseline collateral flow disappeared after CABG in 12 of 14 patients with grafting of the RCA but persisted in all patients without such grafting. Physiologic flow in the inferior wall was detected by TEE in a total of 27 patients at baseline and in 38 patients after CABG (p = 0.0018); its peak velocity increased after surgery only in the subgroup of patients with grafting of the RCA. In conclusion, these findings indicate that Doppler TEE may detect collateral flow in the inferior left ventricular wall, and that there are typical changes in collateral and physiologic flow after CABG.

Heart rate variability and cardiac troponin I are incremental and independent predictors of one-year all-cause mortality after major noncardiac surgery in patients at risk of coronary artery disease.

OBJECTIVES: The aim of this study was to determine whether perioperative measurements of heart rate variability (HRV) and cardiac troponin I (cTnI) add additional prognostic information to established risk scores for first-year mortality in patients at risk of coronary artery disease (CAD) undergoing major noncardiac surgery. BACKGROUND: In cardiac-risk patients undergoing major noncardiac surgery, the short- and long-term prognoses are mainly influenced by perioperative cardiac complications. Heart rate variability and cTnI are important prognostic markers in patients with congestive heart failure and myocardial infarction. METHODS: In a prospective study, 173 patients with CAD or at high risk of CAD undergoing major noncardiac surgery were followed up for one year. The main outcome measure was all-cause mortality. In addition to clinical parameters and established risk scores, HRV and cTnI were assessed perioperatively. RESULTS: Twenty-eight (16%) patients died within one year. Multivariate logistic regression analysis revealed three findings that were independently associated with death within the first year after surgery: the revised cardiac risk index (odds ratio 6.2 [95% confidence interval 1.6 to 25], depressed HRV before induction of anesthesia (16.2 [2.8 to 94]), and elevation of cTnI on postoperative day 1 or 2 (9.8 [3.0 to 32]). CONCLUSIONS: Depressed HRV before induction of anesthesia and elevated cTnI postoperatively are independent and powerful predictors of one-year mortality for patients at risk of CAD undergoing major noncardiac surgery and add incremental prognostic information to established risk scores that only consider preoperative information.

A randomized comparison of right ventricular function after on-pump versus off-pump coronary artery bypass graft surgery.

OBJECTIVES: Right ventricular dysfunction occurs very soon after conventional coronary bypass surgery with cardiopulmonary bypass and might not recover within 1 year after the operation. It has been postulated that performing coronary surgery without cardiopulmonary bypass might preserve right ventricular function. We hypothesized that right ventricular global and overall systolic functions are better preserved 3 months after off-pump surgery than after conventional coronary bypass surgery. METHODS: Fifty patients scheduled for elective coronary bypass surgery were randomly assigned to conventional or off-pump surgery. Right ventricular function was assessed by means of transthoracic echocardiographic analysis the day before the operation and 3 months later. Right ventricular myocardial performance index was used as a marker of global right ventricular function, and right ventricular fractional area change was used as a marker of overall right ventricular systolic function. Peak systolic velocities of the lateral tricuspid annulus were studied to assess regional systolic function of the right ventricular free wall. RESULTS: Surgical intervention was completed according to randomization in 48 of 50 patients. Demographic and perioperative characteristics were similar in the 2 groups. Over the study period, right ventricular myocardial performance index and right ventricular fractional area change did not change in comparison with the baseline values in both groups. Peak systolic velocity of the lateral tricuspid annulus was decreased significantly in both groups 3 months after the operation. There were no significant intergroup differences in any echocardiographic marker of right ventricular function. CONCLUSIONS: Global right ventricular function was not better preserved 3 months after off-pump surgery than after conventional coronary bypass surgery.

Effects of on-pump versus off-pump coronary artery bypass graft surgery on right ventricular function.

OBJECTIVES: Right ventricular dysfunction is a possible cause of cardiac failure after coronary surgery. The use of cardiopulmonary bypass is regarded as a major cause for its occurrence, and it has been postulated that performing coronary surgery without cardiopulmonary bypass might reduce ventricular dysfunction. Therefore, this prospective, randomized, controlled study tested the hypothesis that off-pump coronary surgery would better preserve right ventricular systolic and diastolic function than conventional bypass surgery. METHODS: Fifty patients scheduled for elective coronary artery bypass surgery were randomly assigned to conventional or off-pump surgery. Right ventricular function was assessed by intraoperative transesophageal echocardiography immediately before and after coronary surgery. Right ventricular ejection fraction was used as a marker of global systolic function and tricuspid early/late (atrial) ratio as a marker of the global diastolic function. Peak systolic and early diastolic velocities of the lateral tricuspid annulus were studied to assess systolic and diastolic function in the area of the right ventricular free wall. RESULTS: Surgery was completed according to randomization in 48 of 50 patients. Preoperative characteristics were similar in both groups. Intraoperative differences between the two groups included a higher volume of allogeneic blood transfusion in the conventional surgery group. At the end of surgery, global systolic right ventricular function was similarly maintained and diastolic function similarly impaired in both groups. There were no significant intergroup differences in any of the echocardiographic markers of right ventricular function. CONCLUSIONS: Off-pump surgery did not better preserve right ventricular systolic and diastolic function than did conventional coronary surgery.

Transesophageal echocardiography for monitoring segmental wall motion during off-pump coronary artery bypass surgery.

In this prospective, observational study, we evaluated whether transesophageal echocardiography allows for monitoring left ventricular segmental wall motion during cardiac displacement for off-pump coronary artery bypass (OPCAB) surgery. On the basis of a pilot study that showed frequent loss of transgastric views during OPCAB surgery, we analyzed only midesophageal views. The midesophageal 4-chamber view, 2-chamber view, and long-axis view were recorded in 60 patients after opening the chest and placing an epicardial stabilizer on the displaced heart. Using the 16-segment model, 2 echocardiographers independently performed offline analysis of segmental wall motion. The percentage of patients in whom >or=14 left ventricular segments were readable was calculated at baseline and after cardiac displacement and placement of an epicardial stabilizer. At baseline, >or=14 segments were readable in 59 (98%) of 60 patients. After cardiac displacement, >or=14 segments were readable during 58 (76%) of 76 revascularizations of the left anterior descending coronary artery (P < 0.01 versus baseline), during 33 (83%) of 40 revascularizations of the left circumflex coronary artery (P < 0.01 versus baseline), and during 29 (94%) of 31 revascularizations of the right coronary artery (not significant). We conclude that the number of readable segments decreased after cardiac displacement but that availability of >or=14 readable segments allowed for reliable monitoring of segmental wall motion in 4 of 5 patients during OPCAB surgery.