Influence of anesthesia on hemodynamic assessment of mitral stenosis severity.

BACKGROUND: The treatment of choice for severe rheumatic mitral stenosis (MS) is balloon mitral valvuloplasty (BMV). Assessment of MS severity is usually performed by echocardiography. Before performing BMV, invasive hemodynamic assessment is also performed. The effect of anesthesia on the invasive assessment of MS severity has not been studied. The purpose of the present study was to assess changes in invasive hemodynamic measurement of MS severity before and after induction of general anesthesia. METHODS: The medical files of 22 patients who underwent BMV between 2014 and 2020 were reviewed. Medical history, laboratory, echocardiographic and invasive measurements were collected. Anesthesia induction was performed with etomidate or propofol. Pre-procedural echocardiographic measurements of valve area using pressure half time, and continuity correlated well with invasive measurements using the Gorlin formula. RESULTS: After induction of anesthesia the mean mitral valve gradient dropped by 2.4 mmHg (p = 0.153) and calculated mitral valve area (MVA) increased by 0.2 cm2 (p = 0.011). A wide variability in individual response was observed. While a drop in gradient was noted in 14 patients, it increased in 7. Gorlin derived MVA rose in most patients but dropped in 4. Assuming a calculated MVA of 1.5 cm2 and below to define clinically significant MS, 4 patients with pre-induction MVA of 1.5 cm2 or below had calculated MVA above 1.5 cm2 after induction. CONCLUSIONS: The impact of general anesthesia on the hemodynamic assessment of MS is heterogeneous and may lead to misclassification of MS severity.

Non-invasive assessment of experimental autoimmune myocarditis in rats using a 3 T clinical MRI scanner.

AIMS: The aim of this study was to assess the use of a 3 T clinical cardiac magnetic resonance (CMR) scanner to detect injury to the heart in experimental autoimmune myocarditis (EAM). METHODS AND RESULTS: The use of 3 T CMR for the detection of cardiac injury was assessed in EAM (n = 55) and control (n = 10) male Lewis rats. Animals were evaluated with serial CMR imaging studies, using a 3 T scanner, and with 2D echocardiography before, and at 2 and 5 weeks after EAM induction. By CMR, regional wall motion abnormalities were noted in seven out of eight rats with myocarditis 5 weeks after induction. Subsequently, the rats developed significant left ventricular (LV) dilatation, wall thickening, and pericardial effusion. Average LV systolic and diastolic volumes increased from 131 ± 10 to 257 ± 20 µL (P = 0.0008), and from 309 ± 14 to 412 ± 24 µL (P < 0.0001), and ejection fraction markedly deteriorated (from 58 ± 2 to 37 ± 5%; P = 0.0003). Areas of fibrosis were located by late gadolinium enhancement (LGE) CMR at the subepicardium, mainly within the anterior, lateral, and inferior walls. The extent and location of LGE were highly correlated (r = 0.94; P < 0.0001) with areas of myocardial fibrosis by histopathology, with 85% sensitivity and 86% specificity. CONCLUSION: A clinical 3 T CMR scanner enables accurate detection, quantification, and monitoring of experimental myocarditis in rats, and could be used for translational research to study the pathophysiology of the disease and evaluate novel therapies.

Reliability of visual assessment of global and segmental left ventricular function: a multicenter study by the Israeli Echocardiography Research Group.

BACKGROUND: The purpose of this multicenter study was to determine the reliability of visual assessments of segmental wall motion (WM) abnormalities and global left ventricular function among highly experienced echocardiographers using contemporary echocardiographic technology in patients with a variety of cardiac conditions. METHODS: The reliability of visual determinations of left ventricular WM and global function was calculated from assessments made by 12 experienced echocardiographers on 105 echocardiograms recorded using contemporary echocardiographic equipment. Ten studies were reread independently to determine intraobserver reliability. RESULTS: Interobserver reliability for visual differentiation between normal, hypokinetic, and akinetic segments had an intraclass correlation coefficient of 0.70. The intraclass correlation coefficient for dichotomizing segments into normal versus other abnormal was 0.63, for hypokinetic versus other scores was 0.26, and for akinetic versus other scores was 0.58. Similar results were found for intraobserver reliability. Interobserver reliability for WM score index was 0.84 and for left ventricular ejection fraction was 0.78. Similar values were obtained for the intraobserver reliability of WM score index and ejection fraction. Compared to angiographic data, the accuracy of segmental WM assessments was 85%, and correct determination of the culprit artery was achieved in 59% of patients with myocardial infarctions. CONCLUSION: Among experienced readers using contemporary echocardiographic equipment, interobserver and intraobserver reliability was reasonable for the visual quantification of normal and akinetic segments but poor for hypokinetic segments. Reliability was good for the visual assessment of global left ventricular function by WM score index and ejection fraction.

A new tool for automatic assessment of segmental wall motion based on longitudinal 2D strain: a multicenter study by the Israeli Echocardiography Research Group.

BACKGROUND: Identification and quantification of segmental left ventricular wall motion abnormalities on echocardiograms is of paramount clinical importance but is still performed by a subjective visual method. We constructed an automatic tool for assessment of wall motion based on longitudinal strain. METHODS AND RESULTS: Echocardiograms of 105 patients (3 apical views) were blindly analyzed by 12 experienced readers. Visual segmental scores (VSS) and peak systolic longitudinal strain were assigned to each of 18 segments per patient. Ranges of peak systolic longitudinal strain that best fit VSS (by receiver operating characteristic analysis) were used to generate automatic segmental scores (ASS). Comparisons of ASS and VSS were performed on 1952 analyzable segments. There was agreement of wall motion scores between both methods in 89.6% of normal, 39.5% of hypokinetic, and 69.4% of akinetic segments. Correlation between methods was r=0.63 (P<0.0001). Interobserver and intraobserver reliability using interclass correlation for scoring segmental wall motion into 3 scores by ASS was 0.82 and 0.83 and by VSS 0.70 and 0.69, respectively. Compared with VSS (majority rule), ASS had a sensitivity, specificity, and accuracy of 87%, 85%, and 86%, respectively. ASS and VSS had similar success rates for correct identification of wall motion abnormalities in territories supplied by culprit arteries. VSS had greater specificity and positive predictive values, whereas ASS had higher sensitivity and negative predictive values for identifying the culprit artery. CONCLUSIONS: Automatic quantification of wall motion on echocardiograms by this tool performs as well as visual analysis by experienced echocardiographers, with a greater reliability and similar agreement to angiographic findings.