The use of artificial intelligence for predicting postinfarction myocardial viability in echocardiographic images.

BACKGROUND: Evaluation of standard echocardiographic examination with artificial intelligence may help in the diagnosis of myocardial viability and function recovery after acute coronary syndrome. METHODS: Sixty-one consecutive patients with acute coronary syndrome were enrolled in the present study (43 men, mean age 61 ± 9 years). All patients underwent percutaneous coronary intervention (PCI). 533 segments of the heart echo images were used. After 12 ± 1 months of follow-up, patients had an echocardiographic evaluation. After PCI each patient underwent cardiac magnetic resonance (CMR) with late enhancement and low-dose dobutamine echocardiographic examination. For texture analysis, custom software was used (MaZda 5.20, Institute of Electronics).Linear and non-linear (neural network) discriminative analyses were performed to identify the optimal analytic method correlating with CMR regarding the necrosis extent and viability prediction after follow-up. Texture parameters were analyzed using machine learning techniques: Artificial Neural Networks, Namely Multilayer Perceptron, Nonlinear Discriminant Analysis, Support Vector Machine, and Adaboost algorithm. RESULTS: The mean concordance between the CMR definition of viability and three classification models in Artificial Neural Networks varied from 42% to 76%. Echo-based detection of non-viable tissue was more sensitive in the segments with the highest relative transmural scar thickness: 51-75% and 76-99%. The best results have been obtained for images with contrast for red and grey components (74% of proper classification). In dobutamine echocardiography, the results of appropriate prediction were 67% for monochromatic images. CONCLUSIONS: Detection and semi-quantification of scar transmurality are feasible in echocardiographic images analyzed with artificial intelligence. Selected analytic methods yielded similar accuracy, and contrast enhancement contributed to the prediction accuracy of myocardial viability after myocardial infarction in 12 months of follow-up.

Handheld ultrasound in cardiology: Current perspective.

The advantages of ultrasonography do not need to be discussed. It is suitable for use in diverse clinical settings and environments by operators with different backgrounds. Recent technological advances have led not only to the enhancement of the diagnostic capabilities of stationary ultrasound systems but also to miniaturization, which in turn led to the introduction of smartphone-sized handheld ultrasound devices (HUDs), designed to be used at bedside to improve and extend the scope of physical examination. Although diagnostic capabilities of HUDs are expanding, according to guidelines, they cannot be perceived as a tool suitable for performing full echocardiographic examination. However, their ultraportability made them essential for the bedside assessment, with the particular emphasis on the bedside focus cardiac ultrasound (FoCUS)-goal-oriented, limited echocardiographic screening. Clinically relevant cardiological targets suggested for HUDs include the assessment of left ventricular (LV) systolic function and size, assessment of other cardiac chambers, identification of gross valvular abnormalities, and detection of the pathological masses within the heart cavities. Handheld ultrasound devices may be also helpful in identifying pleural effusion or subpleural consolidations; furthermore, brief ultrasonographic assessment of "lung comets" enables the estimation of the level of congestion. Ultrasound screening for certain vascular abnormalities also appears promising. The limitations of HUDs are rather obvious and caution is needed to distinguish the role of HUD-based bedside-limited scan from comprehensive stationary echocardiography. It appears that the right approach is to treat them as complementary tools proving their capabilities in diverse clinical scenarios.

Integrated Assessment of Heart, Lung and Lower Extremity Veins Using Hand-Held Ultrasound Device in COVID-19 Patients: Feasibility and Clinical Application.

The emergence of the COVID-19 pandemic caused a significant shortage of medical personnel and the prioritization of life-saving procedures on internal medicine and cardiology wards. Thus, the cost- and time-effectiveness of each procedure proved vital. Implementing elements of imaging diagnostics into the physical examination of COVID-19 patients could prove beneficial to the treatment process, providing important clinical data at the moment of admission. Sixty-three patients with positive COVID-19 test results were enrolled into our study and underwent physical examination expanded with a handheld ultrasound device (HUD)-performed bedside assessment included: right ventricle measurement, visual and automated LVEF assessment, four-point compression ultrasound test (CUS) of lower extremities and lung ultrasound. Routine testing consisting of computed-tomography chest scanning, CT-pulmonary angiogram and full echocardiography performed on a high-end stationary device was completed in the following 24 h. Lung abnormalities characteristic for COVID-19 were detected in CT in 53 (84%) patients. The sensitivity and specificity of bedside HUD examination for detecting lung pathologies was 0.92 and 0.90, respectively. Increased number of B-lines had a sensitivity of 0.81, specificity 0.83 for the ground glass symptom in CT examination (AUC 0.82; p < 0.0001); pleural thickening sensitivity 0.95, specificity 0.88 (AUC 0.91, p < 0.0001); lung consolidations sensitivity 0.71, specificity 0.86 (AUC 0.79, p < 0.0001). In 20 patients (32%), pulmonary embolism was confirmed. RV was dilated in HUD examination in 27 patients (43%), CUS was positive in two patients. During HUD examination, software-derived LV function analysis failed to measure LVEF in 29 (46%) cases. HUD proved its potential as the first-line modality for the collection of heart-lung-vein imaging information among patients with severe COVID-19. HUD-derived diagnosis was especially effective for the initial assessment of lung involvement. Expectedly, in this group of patients with high prevalence of severe pneumonia, HUD-diagnosed RV enlargement had moderate predictive value and the option to simultaneously detect lower limb venous thrombosis was clinically attractive. Although most of the LV images were suitable for the visual assessment of LVEF, an AI-enhanced software algorithm failed in almost 50% of the study population.

Feasibility and clinical utility of real-time tele-echocardiography using personal mobile device-based pocket echocardiograph.

Introduction: Recently introduced microUSB ultrasound probe, which can be connected to personal mobile device constitutes a new class of diagnostic pocket size imaging devices (PSID).The aim of this study was to assess the feasibility and clinical utility of real-time tele-echocardiography with the use such device. Material and methods: The study group comprised 30 patients (18 men and 12 women; mean age: 54 ±14 years; mean body mass index: 27 ±6 kg/m2), admitted to various hospital departments (infectious diseases, internal medicine and cardiology). All patients underwent focused echocardiographic examination performed by an inexperienced operator using PSID and collaborating remotely in real-time with cardiologist by means of tele-consultation. Before commencing the examination, the operators underwent 1 h training in use of the PSID. Results: In most of patients PSID imaging provided sufficient diagnostic image quality. The dimensions of left ventricle, left atrium and the aorta obtained during the this examination showed good correlation with standard echocardiography (r = 0.89, r = 0.82, r = 0.92 respectively), but the correlation for TAPSE measurements was less pronounced (r = 0.52). The agreement in detection of pathologies (wall motion abnormalities, morphological and functional valvular abnormalities) between the tele-echocardiography and standard echocardiographic examination was good to very good (κ ranged from 0.648 to 0.823). Conclusions: Pocket size imaging devices allows an inexperienced operator to perform a focused echocardiographic examination under a remote supervision of an experienced cardiologist. The introduction of new technology in the form of PSID with tele-echocardiography feature can revolutionize access to this imaging technique.

Continuous hands-free monitoring of echocardiographic exercise test using probe fixation device.

BACKGROUND: Stress echocardiography has been widely used in clinical practice for decades and has recently gained even more importance in diagnostic approaches to ischemic heart disease. However, it still has numerous limitations. Despite advantages of physical exercise as most physiologic stressor, it is impossible to continuously monitor the cardiac function during treadmill test and difficult to maintain an optimal acoustic window during cycle ergometer exercise tests. The aim herein, is to assess the feasibility of probe fixation for use during exercise echocardiography. METHODS: Forty-eight subjects (47 men, mean age 42 ± 17 years, 25 healthy volunteers, 23 patients with suspected coronary artery disease) were included in this study. All subjects underwent exercise stress test on treadmill (32 cases) or cycle ergometer (16 cases). Both sector and matrix probes were used (in 17 and 31 tests, respectively). The semi-quantitative quality of acquired apical views were assessed at each stage using a four-point grading system. RESULTS: The mean time required for probe fixation was 9 ± 2 min. At baseline, 10 patients had at least one apical window of quality precluding reliable analysis. Twenty-five patients required probe repositioning during exercise (more often on a treadmill). During peak exercise quality of images in all views declined, but for diagnostic purposes it remained sufficient in 29 patients. Thus, 76% of performed tests (60% study population) had sufficient image quality. CONCLUSIONS: Probe fixation offers the possibility of continuous acquisition of echocardiographic images during physical exercise. The device is suitable almost exclusively for male patients and in some patients requires repositioning.

Flow-mediated skin fluorescence: A novel method for the estimation of sleep apnea risk in healthy persons and cardiac patients.

BACKGROUND: A pilot study revealed a relationship between the results of flow mediated skin fluorescence (FMSF) and of ECG-Holter-based estimated apnea/hypopnea index (eAHI) in asymptomatic individuals. The aim of this study was to test whether the results of FMSF show a relationship with the eAHI in patients with coronary artery disease or aortic stenosis. METHODS: Twenty-one patients (12 coronary disease, 9 aortic stenosis) and 37 healthy volunteers were included. FMSF was assessed before, during and after the pressure occlusion of the brachial artery, using a prototype device allowing the quantification of skin fluorescence. The values of FMSF expressed as baseline (BASE), maximum (MAX), and minimum (MIN) were analyzed. The percentages of ischemic response (IR) and hyperemic response (HR) were calculated. The eAHI was assessed from night ECG-Holter recordings. Differences between the groups and the relationships between the parameters were analyzed statistically. RESULTS: Mean ± standard deviation of BASE, MAX, MIN and IR were not significantly different in both groups (p > 0.05). HR was significantly lower in cardiac patients (14.7 ± 7.5 vs. 11.8 ± 5.1; p = 0.048), whose eAHI was significantly higher (11.0 ± 7.4 vs. 36.3 ± 16.5; p < 0.01). Negative correlation for MAX and eAHI was found in volunteers and patients: r = -0.38, p = 0.02 and r = -0.47, p = 0.03, respectively. In volunteers, HR had a negative correlation with eAHI: r = -0.34, p = 0.04. CONCLUSIONS: This pioneer study confirms that FMSF can be used to detect the negative correlation between MAX fluorescence and eAHI not only among healthy volunteers, but also among cardiac patients with coronary artery disease or aortic stenosis.

Complexity of changes in right ventricular morphology and function in patients undergoing cardiac surgery - 3D echocardiographic study.

BACKGROUND: An impairment of standard echocardiographic parameters of right ventricular (RV) function is a known phenomenon in patients undergoing cardiac surgery, but its significance remains unclear. AIMS: This study aimed to assess changes in RV function in patients undergoing cardiac surgery using speckle tracking and 3D echocardiography. METHODS: The study population comprised 122 patients referred for cardiac surgery. Transthoracic echocardiographic (TTE) examinations were performed: before the surgery (TTE1), 1 week after surgery (TTE2), and 1 year after surgery (TTE 3). Parameters measured during these examinations included both standard and advanced indices of the RV size and function, as well as a new parameter introduced by our team - RV shortening fraction (RV SF). RESULTS: TTE1 was performed on average (standard deviation [SD]) 24 (15) hours before surgery, whereas TTE2 and TTE3 were performed on average 7.2 (3) days and 346 (75) days after the surgery, respectively. A postoperative impairment of parameters of RV longitudinal function was observed (P <0.001). However, neither the RV size assessed by both 2D and 3D techniques changed, nor the global RV function measured with the use of fractional area change and ejection fraction. Additionally, during the postoperative period, an increase in the value of an RV SF by 12.9% was observed. After 12 months we observed an improvement in the parameters of the longitudinal RV function. CONCLUSIONS: Uncomplicated cardiac surgery causes transient impairment of the longitudinal systolic RV function, with no influence on the global RV function. The preservation of global function results from increased RV SF. After 12 months, an improvement of the longitudinal function can be observed.

Inter- and Intraobserver Repeatability of Myocardial Flow Reserve Values Determined with SPECT Study Using a Discovery NM530c Camera and Corridor 4DM Software.

BACKGROUND: Myocardial blood flow (MBF) and flow reserve (MFR) examination, especially useful in the diagnosis of multivessel coronary artery disease (CAD), can be assessed with a cadmium-zinc-telluride (CZT) SPECT gamma camera, as an alternative to the expensive and less available PET. However, study processing is not free from subjective factors. Therefore, this paper aims to evaluate intra- and interobserver repeatability of MBF and MFR values obtained by the same operator and two independent operators. METHODS: This study included 57 adult patients. MBF and MFR were assessed using a Discovery NM530c camera in a two-day, rest/dipyridamople protocol, using 99mTc-MIBI. Data were processed using Corridor4DM software, twice by one operator and once by another operator. RESULTS: The repeatability of the assessed values was quite good in the whole myocardium, LAD and LCX vascular territories, but was poor in the RCA territory. CONCLUSIONS: The poor repeatability of MBF and MFR in RCA vascular territory can be explained by poor automatic orientation of the heart axis during post-processing and a so-called "cardiac creep" phenomenon. Better automatic heart orientation and introduction of automatic motion correction is likely to drastically improve this repeatability. In the present state of the software, PET is better for patients requiring assessment of MFR in the RCA territory.

Higher rate of aortic stenosis progression in patients with bicuspid versus tricuspid aortic valve - A single center experience.

PURPOSE: We sought to investigate aortic stenosis (AS) progression rate (pr) with the comparison between bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV) morphology. MATERIALS AND METHODS: We compared ASpr in patients with BAV and TAV examined by transthoracic echocardiography (TTE) in the years 2004-2019. RESULTS: Data from 363 TTEs in 161 AS patients (median age 70 [61-77] years; 63% men; 25% with BAV; 20% with severe AS) performed at different time points (median time interval 10 months) was analyzed. We assessed changes of AS severity with peak velocity through aortic valve (Vmax), mean/peak pressure gradients (MG/PG), aortic valve area by planimetry and continuity equation (AVAce). We compared pr (defined as parameter change per year) between the BAV and the TAV groups. BAV patients showed faster ASpr with odds ratio 3.467 and 95% confidence intervals 1.36 to 8.86, moreover, expressed as a quicker AVAce decrease 0 (-0.4-0.0) in the BAV vs. 0 (-0.15 - 0.0) cm2/year in the TAV group, p â€‹= â€‹0.02. Furthermore, in BAV, female sex was associated with lower ASpr (p â€‹= â€‹0.01), and in the whole group a larger aortic diameter was a predictor of faster progression (p â€‹< â€‹0.001). CONCLUSION: The ASpr, expressed as a decrease in the AVAce, was faster in BAV. Moreover, ASpr depends on both: valve morphology being faster in BAV and Vmax increase. Furthermore, the female sex was related to slower pace of AVA reduction in BAV subgroup whereas the larger baseline aortic diameter associated to faster AS progression in the whole studied group.

Echocardiography during the coronavirus disease 2019 pandemic - the impact of the vaccination program. A 2021 update of the expert opinion of the Working Group on Echocardiography of the Polish Cardiac Society.

The coronavirus disease 2019 (COVID-19) pandemic resulted in an urgent need to reorganize the work of echocardiography laboratories in order to ensure the safety of patients and the protection of physicians, technicians, and other staff members. In the previous Expert Opinion of the Working Group on Echocardiography of Polish Cardiac Society we provided recommendations for the echocardiographic services, in order to ensure maximum possible safety and efficiency of imagers facing epidemic threat. Now, with much better knowledge and larger experience in treating COVID-19 patients and with introduction of vaccination programs, we present updated recommendations for performing transthoracic and transesophageal examinations, including information on the potential impact of personnel and the patient vaccination program, and growing numbers of convalescents on performance of echocardiographic laboratories, with the goal of their ultimate reopening.

Selected Aspects of Electrochemical Micromachining Technology Development.

The paper focuses on the fundamentals of electrochemical machining technology de-elopement with special attention to applications for micromachining. In this method, a material is removed during an anodic electrochemical dissolution. The method has a number of features which make it attractive technology for shaping parts with geometrical features in range of micrometres. The paper is divided into two parts. The first one covers discussion on: general characteristics of electrochemical machining, phenomena in the gap, problems resulting from scaling down the process and electrochemical micromachining processes and variants. The second part consists of synthetic overview of the authors' research on localization of pulse electrochemical micromachining process and case studies connected with application of this method with use of universal cylindrical electrode-tool for shaping cavities in 1.4301 stainless steel. The latter application was conducted in two following variants: electrochemical contour milling and shaping carried out with sidewall surface of rotating tool. In both cases, the obtained shape is a function of electrode tool trajectory. Selection of adequate machining strategy allows to obtain desired shape and quality.

Artificial Intelligence-Powered Measurement of Left Ventricular Ejection Fraction Using a Handheld Ultrasound Device.

The aim of this study was to assess the accuracy of an algorithm for automated measurement of left ventricular ejection fraction (LVEF) available on handheld ultrasound devices (HUDs). One hundred twelve patients admitted to the cardiology department underwent assessment performed with an HUD. In each case, the four-chamber apical view was obtained, and LVEF was calculated with LVivo software. Subsequently, during the examination performed with the use of the stationary echocardiograph, the 3-D measurement of LVEF was recorded. The average LVEFs measured with LVivo and the 3-D reference method were 46 ± 14% and 48 ± 14%, respectively. The correlation between the measurements obtained with the HUD and 3-D evaluation was high (r = 0.92, 95% confidence interval: 0.87-0.95, p < 0.0001). The mean difference between the LVEF obtained with LVivo and the 3-D LVEF was not significant (mean difference: -0.61%, 95% confidence interval: -1.89 to 0.68, p = 0.31). The LVivo software despite its limitations is capable of the accurate LVEF measurement when the acquired views are of at least good imaging quality.

No effects of cardiac resynchronization therapy and right ventricular pacing on the right ventricle in patients with heart failure and atrial fibrillation.

BACKGROUND: The right ventricle (RV) function is crucial in heart failure with reduced ejection fraction (HFrEF), especially in patients with atrial fibrillation (AF). Aims. To assess the RV structure and function in patients with HFrEF, permanent atrial fibrillation (AF), cardiac resynchronization therapy (CRT) and RV pacing (RVp) with two- and three-dimensional echocardiography. Methods. Patients with ischemic HFrEF (NYHA II-III; LVEF ≤40%) were enrolled. The studied groups were: sinus rhythm (SR, control); AF and no implanted devices - AF/0; AF and CRT - AF/CRT; AF and RVp - AF/RVp. Two- and three-dimensional echocardiographic parameters of RV structure and function were analyzed in study groups. Results. The study included a group of 126 patients: n = 32 with SR, n = 28 with AF/0, n = 25 with AF/CRT and n = 41 with AF/RVp. Results were worse in AF groups than in SR: right ventricular ejection fraction, %, mean (SD): SR - 48.2 (7.5), AF/0 - 36.5 (6.5), AF/CRT - 38.3 (7.6), AF/RVp - 37.1 (7.7), p < .001. Other parameters lower in AF groups than in SR were: RV end-systolic volume, longitudinal strain of the free wall and tricuspid lateral annular systolic velocity. There were no differences between groups with AF and CRT and RV pacing in other analyzed parameters between AF groups and SR. Conclusions. In heart failure with reduced left ventricular ejection fraction and atrial fibrillation right ventricular pacing and cardiac resynchronization therapy were not associated with modified right ventricular function. Further prospective studies are needed to evaluate prognostic significance of these results.

On the search for the right definition of heart failure with preserved ejection fraction.

The definition of heart failure with preserved ejection fraction (HFpEF) has evolved from a clinically based "diagnosis of exclusion" to definitions focused on objective evidence of diastolic dysfunction and/or elevated left ventricular filling pressures. Despite advances in our understanding of HFpEF pathophysiology and the development of more sophisticated imaging modalities, the diagnosis of HFpEF remains challenging, especially in the chronic setting, given that symptoms are provoked by exertion and diagnostic evaluation is largely conducted at rest. Invasive hemodynamic study, and in particular - invasive exercise testing, is considered the reference method for HFpEF diagnosis. However, its use is limited as opposed to the high number of patients with suspected HFpEF. Thus, diagnostic criteria for HFpEF should be principally based on non-invasive measurements. As no single non-invasive variable can adequately corroborate or refute the diagnosis, different combinations of clinical, echocardiographic, and/or biochemical parameters have been introduced. Recent years have brought an abundance of HFpEF definitions. Here, we present and compare four of them: 1) the 2016 European Society of Cardiology criteria for HFpEF; 2) the 2016 echocardiographic algorithm for diagnosing diastolic dysfunction; 3) the 2018 evidence-based H2FPEF score; and 4) the most recent, 2019 Heart Failure Association HFA-PEFF algorithm. These definitions vary in their approach to diagnosis, as well as sensitivity and specificity. Further studies to validate and compare the diagnostic accuracy of HFpEF definitions are warranted. Nevertheless, it seems that the best HFpEF definition would originate from a randomized clinical trial showing a favorable effect of an intervention on prognosis in HFpEF.