Visual quantitative estimation: semiquantitative wall motion scoring and determination of ejection fraction

Left ventricular longitudinal strain variations assessed by speckle-tracking echocardiography after a passive leg raising maneuver in patients with acute circulatory failure to predict fluid responsiveness: A prospective, observational study

Background

An association was reported between the left ventricular longitudinal strain (LV-LS) and preload. LV-LS reflects the left cardiac function curve as it is the ratio of shortening over diastolic dimension. The aim of this study was to determine the sensitivity and specificity of LV-LS variations after a passive leg raising (PLR) maneuver to predict fluid responsiveness in intensive care unit (ICU) patients with acute circulatory failure (ACF).

Methods

Patients with ACF were prospectively included. Preload-dependency was defined as a velocity time integral (VTI) variation greater than 10% between baseline (T0) and PLR (T1), distinguishing the preload-dependent (PLD+) group and the preload-independent (PLD-) group. A 7-cycles, 4-chamber echocardiography loop was registered at T0 and T1, and strain analysis was performed off-line by a blind clinician. A general linear model for repeated measures was used to compare the LV-LS variation (T0 to T1) between the two groups.

Results

From June 2018 to August 2019, 60 patients (PLD+ = 33, PLD- = 27) were consecutively enrolled. The VTI variations after PLR were +21% (±8) in the PLD+ group and -1% (±7) in the PLD- group (p<0.01). Mean baseline LV-LS was -11.3% (±4.2) in the PLD+ group and -13.0% (±4.2) in the PLD- group (p = 0.12). LV-LS increased in the whole population after PLR +16.0% (±4.0) (p = 0.04). The LV-LS variations after PLR were +19.0% (±31) (p = 0.05) in the PLD+ group and +11.0% (±38) (p = 0.25) in the PLD- group, with no significant difference between the two groups (p = 0.08). The area under the curve for the LV-LS variations between T0 and T1 was 0.63 [0.48–0.77].

Conclusion

Our study confirms that LV-LS is load-dependent; however, the variations in LV-LS after PLR is not a discriminating criterion to predict fluid responsiveness of ICU patients with ACF in this cohort.

Visual versus fully automated assessment of left ventricular ejection fraction

Introduction

The aim of this study is to compare three different echocardiographic methods commonly used in the assessment of left ventricle (LV) ejection fraction (EF).

Methods

All patients underwent full echocardiography including LVEF assessed using M-mode, automated EF (Auto-EF), and visual estimation by two readers.

Results

We enrolled 268 patients. Auto-EF measurement was feasible in 240 (89.5%) patients. The averaged LVEF was (52% ± 12) with the visual assessment, (51% ± 11) with Auto-EF and (57% ± 13) with M-mode. Using Bland-Altman analysis, we found that the difference between the mean visual and the Auto-EF was not significant (-0.3% [-0.5803-0.0053], P = 0.054). However, the mean EF was significantly different when comparing visual versus M-mode and Auto-EF versus M-mode with the mean differences: (-2.4365 [-2.9946--1.8783], P < 0.0001) and (-2.1490 [-2.7348--1.5631], P < 0.0001) respectively. Inter-observer variability analysis of the visual EF assessment between the two readers showed that intraclass correlation coefficient was 0.953, (95% confidence interval: 0.939-0.965, P < 0.0001), with excellent correlation between the two readers: R = 0.911, P < 0.0001).

Conclusion

The two-dimensional echocardiographic methods using Biplane Auto-EF or visual assessment were significantly comparable, whereas M-mode results in an overestimation of the LVEF.

The Role of Automated 3D Echocardiography for Left Ventricular Ejection Fraction Assessment

Ejection fraction is one of the most powerful determinants of prognosis and is a crucial parameter for the determination of cardiovascular therapies in conditions such as heart failure, valvular conditions and ischaemic heart disease. Among echocardiographic methods, 3D echocardiography has been attributed as the preferred one for its assessment, given an increased accuracy and reproducibility. Full-volume multi-beat acquisitions are prone to stitching artefacts due to arrhythmias and require prolonged breath holds. Single-beat acquisitions exhibit a lower temporal resolution, but address the limitations of multi-beat acquisitions. If not fully automated, 3D echocardiography remains time-consuming and resource-intensive, with suboptimal observer variability, preventing its implementation in routine practice. Further developments in hardware and software, including fully automated knowledge-based algorithms for left ventricular quantification, may bring 3D echocardiography to a definite turning point.

[Perioperative transesophageal echocardiography in non-cardiac surgery. Update]

AIM

The aim of this article is to impart knowledge concerning focused transesophageal echocardiographic examination (TEE) for non-cardiac surgery which is an essential part of perioperative monitoring. It allows a rapid echocardiographic examination without interference with the surgical field or under limited transthoracic examination conditions. New recommendations for a comprehensive perioperative TEE examination with expanded standard views and the recently published consensus statement for a shortened baseline examination were crucial for this study.

MATERIAL AND METHODS

The background is the peer-reviewed literature from PubMed.

RESULTS

Apart from cardiac surgery TEE has two main applications: firstly, the evaluation of patients developing acute life-threatening hemodynamic instability in the operating room, in the emergency room or in the intensive care unit (ICU). Secondly, TEE is used as planned intraoperative monitoring when severe hemodynamic, pulmonary or neurological complications are expected because of the type of surgery or due to the cardiopulmonary medical history of the patient. In 2013 a total of 11 relevant standard views were defined for the basic perioperative TEE examination in non-cardiac surgery. These 11 views should be performed for each patient. Appropriate extension to a comprehensive examination may be necessary if complex pathology is obvious.

DISCUSSION

Even in non-cardiac surgery TEE is an important tool allowing clarification of a life-threatening perioperative hemodynamic instability within a few minutes. Furthermore, the hemodynamic management of high-risk patients can be facilitated. Appropriate qualification and continuous training are necessary in order to assure the competence of the examiner.

Basal hyperaemia is the primary abnormality of perfusion in Takotsubo cardiomyopathy: a quantitative cardiac perfusion positron emission tomography study

AIMS

Takotsubo cardiomyopathy (TTC) is characterized by acute completely reversible regional left ventricle (LV) akinesia and decreased tracer uptake in the akinetic region on semi-quantitative perfusion imaging. The latter may be due to normoperfusion of the akinetic mid/apical area and basal hyperperfusion. Our aim was to examine abnormalities of perfusion in TTC, and we hypothesized that basal hyperperfusion is the primary perfusion abnormality in the acute state.

METHOD AND RESULTS

Twenty-five patients were diagnosed with TTC due to (i) acute onset of symptoms, (ii) typical apical ballooning, (iii) absence of significant coronary disease, and (iv) complete remission on 4-month follow-up. The patients underwent coronary angiography (CAG), echocardiography, cardiac magnetic resonance imaging (CMR), and (13)NH3/(82)Rb positron emission tomography (PET) in the acute state and-except CAG-on follow-up. Patients initially had severe heart failure, mid/apical oedema but no infarction, and a rise in cardiac biomarkers. On initial perfusion PET imaging, eight patients appeared to have normal, whereas 17 patients had impaired LV perfusion. In the latter, flow in the basal region was increased in the acute state (1.5 ± 0.1 vs. 1.2 ± 0.1 mL/g/minRPP-corrected, P < 0.01), whereas midventricular (1.7 ± 0.1 vs. 1.6 ± 0.1 mL/g/minRPP-corrected, P = 0.21) and apical (1.4 ± 0.1 vs. 1.5 ± 0.1 mL/g/minRPP-corrected, P = 0.36) flow was unchanged between acute and follow-up, and within normal range.

CONCLUSION

Our results suggest an abnormal LV perfusion distribution in the acute state of TTC with basal hyperperfusion and a normoperfused akinetic region. The proportion of patients without visualized perfusion abnormalities in the acute state may represent a subgroup with fast remission.

Cardiac ⁹⁹mTc sestamibi SPECT and ¹⁸F FDG PET as viability markers in Takotsubo cardiomyopathy

In patients with heart failure (HF) due to coronary disease, a combined evaluation of perfusion and glucose metabolism by cardiac single photon emission computed tomography (SPECT)/positron emission tomography (PET) can be used to distinguish viable from non-viable myocardium, and current guidelines recommend cardiac SPECT and fluorodeoxyglucose (FDG) PET for viability assessment. Takotsubo cardiomyopathy (TTC) is a disease characterized by acute but reversible HF leaving no scarring. To explore how robust the semi-quantitative viability criteria used in cardiac SPECT and FDG PET stands their ground in a population with TTC. From 1 September 2009 to 1 October 2012, 24 patients suspected of TTC were enrolled in a multimodality cardiac imaging research project. Echocardiography, (99m)Tc SPECT, and (18)F FDG PET were performed during the acute admission and at follow-up 4 months later. Nineteen patients had a final diagnosis of TTC consistent with Mayo Clinic Diagnostic Criteria. Three of these patients were excluded from further analysis, since wall motion abnormalities were not persistent at the time of nuclear imaging. The remaining sixteen patients exhibited a distinct pattern with HF, "apical ballooning" and a perfusion-metabolism defect in the midventricular/apical region. When viability criteria were applied, they identified significant scarring/limited hibernation in the akinetic part of the left ventricle. However, full recovery was found in all TTC patients on follow-up. Using the current guideline-endorsed viability criteria for semiquantitative cardiac SPECT and FDG PET, these modalities failed to demonstrate the presence of viability in the acute state of TTC.

Validation of a novel modified wall motion score for estimation of left ventricular ejection fraction in ischemic and non-ischemic cardiomyopathy

BACKGROUND

Visual determination of left ventricular ejection fraction (LVEF) by segmental scoring may be a practical alternative to volumetric analysis of cine magnetic resonance imaging (MRI). The accuracy and reproducibility of this approach for has not been described. The purpose of this study was to validate a novel segmental visual scoring method for LVEF estimation using cine MRI.

METHODS

362 patients with known or suspected cardiomyopathy were studied. A modified wall motion score (mWMS) was used to blindly score the wall motion of all cardiac segments from cine MRI imaging. The same datasets were subjected to blinded volumetric analysis using endocardial contour tracing. The population was then separated into a model cohort (N=181) and validation cohort (N=181), with the former used to derive a regression equation of mWMS versus true volumetric LVEF. The validation cohort was then used to test the accuracy of this regression model to estimate the true LVEF from a visually determined mWMS. Reproducibility testing of mWMS scoring was performed upon a randomly selected sample of 20 cases.

RESULTS

The regression equation relating mWMS to true LVEF in the model cohort was: LVEF=54.23-0.5761×mWMS. In the validation cohort this equation produced a strong correlation between mWMS-derived LVEF and true volumetric LVEF (r=0.89). Bland and Altman analysis showed no systematic bias in the LVEF estimated using the mWMS (-0.3231%, 95% limits of agreement -12.22% to 11.58%). Inter-observer and intra-observer reproducibility was excellent (r=0.93 and 0.97, respectively).

CONCLUSION

The mWMS is a practical tool for reporting regional wall motion and provides reproducible estimates of LVEF from cine MRI.

Visually estimated ejection fraction by two dimensional and triplane echocardiography is closely correlated with quantitative ejection fraction by real-time three dimensional echocardiography

Background

Visual assessment of left ventricular ejection fraction (LVEF) is often used in clinical routine despite general recommendations to use quantitative biplane Simpsons (BPS) measurements. Even thou quantitative methods are well validated and from many reasons preferable, the feasibility of visual assessment (eyeballing) is superior. There is to date only sparse data comparing visual EF assessment in comparison to quantitative methods available. The aim of this study was to compare visual EF assessment by two-dimensional echocardiography (2DE) and triplane echocardiography (TPE) using quantitative real-time three-dimensional echocardiography (RT3DE) as the reference method.

Methods

Thirty patients were enrolled in the study. Eyeballing EF was assessed using apical 4-and 2 chamber views and TP mode by two experienced readers blinded to all clinical data. The measurements were compared to quantitative RT3DE.

Results

There were an excellent correlation between eyeballing EF by 2D and TP vs 3DE (r = 0.91 and 0.95 respectively) without any significant bias (-0.5 ± 3.7% and -0.2 ± 2.9% respectively). Intraobserver variability was 3.8% for eyeballing 2DE, 3.2% for eyeballing TP and 2.3% for quantitative 3D-EF. Interobserver variability was 7.5% for eyeballing 2D and 8.4% for eyeballing TP.

Conclusion

Visual estimation of LVEF both using 2D and TP by an experienced reader correlates well with quantitative EF determined by RT3DE. There is an apparent trend towards a smaller variability using TP in comparison to 2D, this was however not statistically significant.

Associations between plasma natriuretic peptides and echocardiographic abnormalities in geriatric outpatients

Identification of patients with cardiac dysfunction can be difficult in the geriatric population. Recently, different subtypes of the natriuretic peptide family have been advocated as biomarker for the diagnosis of heart failure in the emergency department setting. In this study we looked at associations between natriuretic peptide plasma levels and echocardiographic abnormalities in geriatric outpatients. Two-dimensional transthoracic echocardiography was performed in 209 community-dwelling subjects, visiting the geriatric outpatient clinic of our university hospital. Subjects were 65 years or older and had no markedly impaired cognitive function. Mean atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) plasma levels were respectively 11.0 and 10.8 pmol/l. BNP, but not ANP correlated with left ventricular dysfunction and left ventricular mass, whereas both peptides correlated with left atrial dimension and valvular lesions. A natriuretic peptide level in the highest tertile was associated with a higher risk of any echocardiographic abnormality, with odds ratios for BNP of 7.15 (range 2.15-23.71), and for ANP of 3.07 (range 1.15-8.16). In conclusion, elevated BNP and ANP plasma levels are closely related to cardiac abnormalities in elderly subjects. The association between cardiac abnormalities and natriuretic peptides is stronger for BNP than for ANP, hence for detection of cardiac abnormalities measurement of BNP plasma values are preferred over ANP plasma values.

Clinically Compressed Digital Echocardiography: A Patient-safe Alternative to Videotape Review

Introduction: Digital storage of echocardiographic data offers logistical advantages over videotape archival. However, limited information is available on the accuracy of clinically compressed digitised examinations, an important consideration for patient safety. Materials and Methods: Transthoracic echocardiograms of 520 consecutive patients were prospectively acquired digitally and on videotape. Two echocardiologists, in consensus, reported studies in both formats sequentially. Using the videotape as a reference, the significance of any reported differences was graded from both imaging and clinical standpoints, and the reasons for these differences identified. Results: From an imaging perspective, differences between digital and videotaped studies were absent or minor in 459 cases (88%), fairly significant in 55 (11%) and very significant in 6 (1%). The main reasons for the observed differences were inadequate acquisition of optimal views (59%), an insufficient number of acquired cardiac cycles (25%) and suboptimal image quality (9%). These differences were considered to be of possible or definite clinical importance in 21 (4%) and 8 (2%) cases, respectively. In multinominal logistic regression models, the only independent predictor of significant difference between digitised and videotaped images was study complexity. Regardless of case complexity, most diagnostic errors arising from digital review were attributable to technical failure rather than observer error. Conclusions: The potential for important errors arising from exclusive reporting of clinically compressed digital echocardiograms is small. Digital echocardiography, as practiced in a routine clinical setting, offers a patient-safe alternative to videotape review. Key words: Clinical implications, Digital echocardiography, Patient safety, Videotape

Visual estimation versus quantitative assessment of left ventricular ejection fraction: a comparison by cardiovascular magnetic resonance imaging

PURPOSE

The aim of this study was to compare the visual and quantitative assessment for left ventricular ejection fraction (LVEF) in normal subjects and patients with impaired LV function.

METHODS

One hundred subjects (40 normal subjects, 40 patients with ischemic cardiomyopathy, and 20 patients with nonischemic cardiomyopathy) were investigated using a 1.5-T cardiovascular magnetic resonance imager. Images were acquired by a fast gradient-echo sequence with steady-state free precession using the standard short-axis method. Left ventricular EF was calculated from the sums of the outlined areas using the Simpson rule. Interobserver variability between the calculated and the visual EF was assessed. Analyses were performed randomly and blinded by 2 independent observers.

RESULTS

Left ventricular EF was significantly underestimated by the visual read in all 3 groups (mean difference: normal subjects -2.6% +/- 2.6%, ischemic cardiomyopathy -1.7% +/- 2.1%, and nonischemic cardiomyopathy -1.2% +/- 2.1%; P < or = .02). The difference was larger in normal subjects than in patients with cardiomyopathy (P = .04). The interobserver variability was smaller for the quantitative assessment than for the visual estimation.

CONCLUSION

Left ventricular EF is underestimated by visual estimation compared with the quantitative assessment. The visual approach for EF assessment may be used for rapid assessment of left ventricular function in clinical practice where accuracy is of less concern. For most accurate analysis, the quantitative standard short axis approach is required.