Comparison of models for quantitative left ventricular wall motion analysis from two-dimensional echocardiograms during acute myocardial infarction.

To develop quantitative analysis of regional left ventricular wall motion in the absence of a gold standard, an objective statistical measure to compare models of wall motion is described. This measure can be derived from wall motion analysis of subgroups of patients with different patterns of wall motion. A priori knowledge of the exact localization of wall motion abnormalities is not needed. Two-dimensional echocardiograms were analyzed from 79 patients with myocardial infarction. The following 4 models were compared: Model I was based on the descent of the base toward the stable apex during systole. Models II and III measured area reduction with fixed- and floating-reference systems, respectively. Model IV was the centerline model. Classification by the electrocardiogram of the myocardial infarction as anterior (n = 37), posterior (n = 17) and inferior (n = 25) provided the a priori probability for classification of myocardial infarction. The a posteriori probability for classification of myocardial infarction was derived from the detection of wall motion abnormalities by echocardiographic analysis. The mean difference between a posteriori and a priori probability is a measure for the diagnostic value of the model, and was measured for 200 regions/patient. Use of the described measure revealed model I to be the most informative model and model III the least informative. Thus, the described statistical measure contributes to the development of regional wall motion analysis.

Pulsed-wave transmitral Doppler do not diagnose moderate acute rejection after heart transplantation.

The value of pulsed-wave transmitral Doppler for the diagnosis of moderate acute rejection was examined in a total of 347 Doppler recordings obtained in 32 consecutive cardiac allograft recipients. Serial Doppler examinations (median, 11 per patient; range, 1 to 23) were performed simultaneously with endomyocardial biopsies from the first week after heart transplantation to a follow-up of 186 days (median; range, 10 to 395 days after transplantation). Pulsed-wave transmitral Doppler did not allow noninvasive diagnosis of moderate acute rejection in individual patients. Peak filling rate normalized for mitral stroke volume, early diastolic velocity, and mean diastolic velocity were significantly increased, whereas diastolic filling period was decreased during moderate acute rejection compared to other biopsy classes. The wide overlap of measurements in individual recipients with or without rejection may be due, however, to a variety of hemodynamic factors after transplantation affecting diastolic function, which are superimposed on the restrictive left ventricular filling pattern caused by persistent mild acute rejection and left ventricular hypertrophy. These hemodynamic factors include pulmonary hypertension, perioperative ischemia, reperfusion injury, and changes in both blood pressure and loading conditions caused by hypertension and its treatment. Differences between studies with regard to the detection of moderate acute rejection by transmitral Doppler may be caused by chance, because most studies were relatively small. Differences in methods, patient selection, duration of follow-up, prevalence of hypertension and left ventricular hypertrophy, and differences in antihypertensive drug regimens may also play a role. Furthermore differences in the incidence of mild acute rejection, its treatment, and the type of maintenance immunosuppressive regimen used may have influenced the outcome of these studies considerably.

Changes in left ventricular function and wall thickness in heart transplant recipients and their relation to acute rejection: an assessment by digitised M mode echocardiography.

OBJECTIVE: Assessment of changes in left ventricular diastolic function and wall thickness after heart transplantation to verify whether these changes predicted acute rejection assessed by endomyocardial biopsy. DESIGN: Follow up according to a predefined protocol of consecutive patients from the first week after transplantation. SETTING: Heart transplantation unit of the Thoraxcentre, University Hospital Rotterdam Dijkzigt, The Netherlands. PATIENTS: All 32 patients undergoing orthotopic heart transplantation from 1 January 1989 to 31 March 1990 were examined. Two were excluded from the analysis. Patients were treated with cyclosporin and low dose steroids. MAIN OUTCOME MEASURES: Data obtained by digitised M mode echocardiography were compared with the results of endomyocardial biopsy (Billingham classification). Mean values for left ventricular wall thickness, internal dimension, and their standardised rates of change and fractional shortening were determined from 4-6 consecutive expiratory beats. Mean values and individual trends during follow up were also investigated for each ultrasound variable. The results of these average values were compared with values in a group of 10 healthy volunteers. RESULTS: Median follow-up was 177 days (range 10-399). Two hundred and sixty three consecutive M mode studies were examined in relation to concurrent biopsy results. No significant differences were observed between the ultrasound variables at the time of moderate acute rejection (Billingham class 2, n = 37) and other biopsy classes (n = 226). Nor did changes in individual patients predict (moderate) acute rejection episodes. Twenty six of the 30 patients had an abnormal (slow) left ventricular relaxation pattern throughout follow up. CONCLUSIONS: Digitised left ventricular M mode echocardiography did not predict the presence of acute rejection. In most patients there was a persistent slow left ventricular relaxation pattern.

Reference systems in echocardiographic quantitative wall motion analysis with registration of respiration.

Registration of respiration allows analysis at the end-expiratory phase and may thus favor the use of the fixed-reference system versus the floating-reference system in echocardiographic quantitative wall motion analysis. Analysis is performed on two-dimensional echocardiograms of 44 normal subjects, 38 patients with anterior myocardial infarction, and 17 patients with posterior myocardial infarction. Two different models for wall motion analysis are applied, each using the fixed-reference system and the floating-reference system, respectively. In patients with anterior myocardial infarction, the fixed-reference system indicates severe wall motion abnormalities at the anterior, septal, and apical walls, whereas the floating-reference system indicates less severe wall motion abnormalities almost equally at every wall. In patients with posterior myocardial infarction, the fixed-reference system indicates severe wall motion abnormalities at the posterior wall, whereas the floating-reference system indicates less severe wall motion abnormalities almost equally at every wall. These findings indicate that the fixed-reference system is superior to the floating-reference system in quantification of wall motion of end-expiratory two-dimensional echocardiograms.

Quantitative echocardiographic analysis of global and regional left ventricular function: a problem revisited.

We recorded two-dimensional echocardiograms simultaneously with the respiration measurements of 20 normal subjects and 20 patients with anterior myocardial infarction. The apical long-axis and four-chamber views were quantitatively analyzed. Measurement variability of global ejection fraction and regional ejection fraction of 100 regions was calculated during inspiration and at end-expiration for two observers. To minimize variability, the endocardial contour was redefined and traced with an improved computer-assisted tracing system. Variability (absolute mean difference) between two beats at end-expiration was significantly less than during inspiration (p less than 0.05): for ejection fraction the variability at end-expiration was 3.4% and the variability during inspiration was 6.4% (mean, 54%; SD, 7%); for regional ejection fraction the variability at end-expiration was 11.8% and the variability during inspiration was 21.5% (mean, 56%; SD, 15%). Intraobserver and interobserver variability values of one beat at end-expiration for ejection fraction were 3.1% and 3.8%, respectively, and 9.5% and 12.8%, respectively, for regional ejection fraction. Variability in patients with myocardial infarction was comparable. This method of recording respiration and analyzing left ventricular function at end-expiration, with a new contour definition and tracing system, provides a measurement variability that is considerably less than that reported in previous echocardiographic studies and that is comparable to angiographic methods.

Two-dimensional echocardiographic analysis of the dynamic geometry of the left ventricle: the basis for an improved model of wall motion.

To establish an appropriate echocardiographic model for wall motion analysis we first determined the precise dynamic geometry of the left ventricle during systole, as visualized by two-dimensional echocardiography. With the epicardial apex and the aortic-ventricular and mitral-ventricular junctions as anatomic landmarks, we quantitatively analyzed apical long-axis views in 61 normal subjects, 41 patients with anterior myocardial infarction, and nine patients with posterior myocardial infarction. Thoracic impedance registration allowed exclusion of extracardiac motion from the measurements. In normal subjects the epicardial apex moved outwardly only 0.6 +/- 0.3 mm (mean +/- standard error). Examination of 15 hearts fixed in formalin revealed apical myocardial thickness of 1.5 +/- 0.2 mm. These data suggest that the observed inward motion of the endocardial apex (4.1 +/- 0.7 mm) resulted from obliteration of the apical cavity as a result of inward motion of the adjacent walls. Translation of the base was considerable in normal subjects (14.1 +/- 0.4 mm) and decreased in myocardial infarction (9.1 +/- 0.5 mm, p less than 0.0001). Unequal shortening of the adjacent walls in anterior and posterior myocardial infarction caused basal rotation in the opposite direction (-9.1 +/- 0.8 degrees and 9.7 +/- 1.4 degrees, respectively, p less than 0.0001 versus that of normal subjects, -3.4 +/- 0.7 degrees). Long-axis rotation was not clinically significant (less than 1 degree). We conclude that during ventricular contraction the apex serves as a stable point, whereas the base translates toward the apex because of shortening of the adjacent walls. We then propose a model for analyzing regional wall motion from two-dimensional echocardiograms on the basis of these observations.

A microcomputer based charting system for documentation of circulatory, respiratory and pharmacological data during anesthesia.

A system for the on-line production of anaesthetic records with a microcomputer is described. The requirements of the system are a keyboard, a video display unit and a colour plotter. The system requires no programming expertise from anaesthetists and nurses. The records have improved information display, patient care and reduced time spent in administration effort. Disadvantages are the relatively high cost and requirement of preprocessing of haemodynamic and respiratory parameters.

Haemodynamic and biochemical variables after induction of anaesthesia with fentanyl and nitrous oxide in patients undergoing coronary artery by-pass surgery.

The effects on the haemodynamic and biochemical parameters of three different anaesthetic induction regimes, namely fentanyl (4.1 micrograms.kg-1 or 15 micrograms.kg-1) plus 60 per cent nitrous oxide with oxygen and fentanyl 15 micrograms.kg-1 plus 60 per cent nitrogen with oxygen, were studied in patients undergoing coronary artery surgery. Fentanyl 15 micrograms.kg-1 with nitrous oxide and oxygen produced simultaneous reductions in oxygen uptake, cardiac index and left ventricular stroke work with an unaltered oxygen extraction. Diastolic blood pressure (an index of coronary artery perfusion) was only slightly reduced, and there were no changes in arterial lactate, glucose and free fatty acids. The lower dose of fentanyl (4.1 micrograms.kg-1) with nitrous oxide produced no haemodynamic changes but decreased the oxygen uptake and extraction. The patients receiving fentanyl 15 micrograms.kg-1 with nitrogen and oxygen showed increases in heart rate, blood pressure, cardiac index and left ventricular stroke work, together with a significant fall in oxygen extraction. Moreover, in the patients who received fentanyl 4.1 micrograms.kg-1 with nitrous oxide and oxygen and fentanyl 15 micrograms.kg-1 with nitrogen and oxygen there were significant increases in blood lactate, glucose and free fatty acids, indicating increased sympathetic activity. We conclude that fentanyl 15 micrograms.kg-1, together with 60 per cent nitrous oxide with oxygen provides a satisfactory haemodynamic and biochemical state during induction of anaesthesia in patients with myocardial function prejudiced by coronary artery insufficiency.

Cardiovascular monitoring with special emphasis on mixed venous oxygen measurements.

With the advent of complicated surgical procedures the need for invasive hemodynamic monitoring has taken a prominent place in the management of patients. This has resulted in improved morbidity and mortality in overall patient care. Along with conventional monitoring of heart rate, arterial pressure and central venous pressure, the information about the function of the left heart is essential. This paper describes the usefulness of Swan-Ganz catheter (SG catheter) during intensive care. The purposes of the study is to determine the relationship between mixed venous oxygen saturation measurement, peripheral skin temperature and volume replacement in the immediate postoperative period, as well as the need for prolonged mechanical ventilation in shocked patients.