The effects of mitral stenosis on right ventricular mechanics assessed by three-dimensional echocardiography.

Mitral stenosis (MS) is a complex valvular pathology with significant clinical burden even today. Its effect on the right heart is often overlooked, despite it playing a considerable part in the symptomatic status. We enrolled 39 mitral valve stenosis patients and 39 age- and gender-matched healthy controls. They underwent conventional, speckle-tracking and 3D echocardiographic examinations. The 3D data was analyzed using the ReVISION software to calculate RV functional parameters. In the MS group, 3D RV ejection fraction (EF) (49 ± 7% vs. 61 ± 4%; p < 0.001), global circumferential (GCS) (- 21.08 ± 5.64% vs. - 25.07 ± 4.72%; p = 0.001) and longitudinal strain (GLS) (- 16.60% ± 4.07% vs. - 23.32 ± 2.82%; p < 0.001) were reduced. When comparing RV contraction patterns between controls, MS patients in sinus rhythm and those with atrial fibrillation, radial (REF) (32.06 ± 5.33% vs. 23.62 ± 7.95% vs. 20.89 ± 6.92%; p < 0.001) and longitudinal ejection fraction (LEF) (24.85 ± 4.06%; 17.82 ± 6.16% vs. 15.91 ± 4.09%; p < 0.001) were decreased in both MS groups compared to controls; however, they were comparable between the two MS subgroups. Anteroposterior ejection fraction (AEF) (29.16 ± 4.60% vs. 30.87 ± 7.71% vs. 21.48 ± 6.15%; p < 0.001) showed no difference between controls and MS patients in sinus rhythm, while it was lower in the MS group with atrial fibrillation. Therefore, utilizing 3D echocardiography, we found distinct morphological and functional alterations of the RV in MS patients.

Investigating the Contraction Pattern of the Zygomaticus Major Muscle and its Clinical Relevance: A Functional MRI Study.

BACKGROUND: Our understanding of facial anatomy has significantly evolved, yet the detailed contraction patterns of facial muscles and their presentation during clinical imaging remain largely unexplored. Understanding the contraction patterns and visual presentation of these muscles, particularly the zygomaticus major could enhance pre-surgical facial assessments and the development of new treatment strategies. METHODS: A total of 34 healthy young individuals (17 female, 17 male) with a mean age of 23.6 (2.4) years [range: 20-30] were investigated regarding the length, thickness, width, and angle of the zygomaticus major muscle in five different facial expressions (i.e., repose, anger, joy, surprise, and sadness) utilizing MR imaging. RESULTS: Joyful expressions caused a reduction in muscle length to 85.6% of its original length and an increase in width (103.4%), thickness (108.4%), and facial angle (2.72°) when compared to that in repose, suggesting isotonic contraction. Conversely, expressions of anger, surprise, and sadness generally led to muscle stretching, seen through changes in length (98.9%, 104.3%, and 102.7%, respectively), width (98.8%, 96.5%, and 99.4%, respectively), and thickness (91.2%, 91.0%, and 102.7%, respectively), with variable alterations in facial angle (0.55°, 1.85°, and 1.00°, respectively) depending on the specific expression. CONCLUSION: This MRI-based study indicates that the zygomaticus major muscle experiences isotonic contraction, characterized by decreased length and increased width and thickness. The findings underline the importance of muscle thickness as a reliable parameter in assessing facial muscle function and offer valuable guidance for practitioners in accurately evaluating muscle performance during different facial expressions. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Clinical and functional relevance of right ventricular contraction patterns in pulmonary hypertension.

BACKGROUND: The right ventricle has a complex contraction pattern of uncertain clinical relevance. We aimed to assess the relationship between right ventricular (RV) contraction pattern and RV-pulmonary arterial (PA) coupling defined by the gold-standard pressure-volume loop-derived ratio of end-systolic/arterial elastance (Ees/Ea). METHODS: Prospectively enrolled patients with suspected or confirmed pulmonary hypertension underwent three-dimensional echocardiography, standard right heart catheterization, and RV conductance catheterization. RV-PA uncoupling was categorized as severe (Ees/Ea < 0.8), moderate (Ees/Ea 0.8-1.29), and none/mild (Ees/Ea ≥ 1.3). Clinical severity was determined from hemodynamics using a truncated version of the 2022 European Society of Cardiology/European Respiratory Society risk stratification scheme. RESULTS: Fifty-three patients were included, 23 with no/mild, 24 with moderate, and 6 with severe uncoupling. Longitudinal shortening was decreased in patients with moderate vs no/mild uncoupling (p <0.001) and intermediate vs low hemodynamic risk (p < 0.001), discriminating low risk from intermediate/high risk with an optimal threshold of 18% (sensitivity 80%, specificity 87%). Anteroposterior shortening was impaired in patients with severe vs moderate uncoupling (p = 0.033), low vs intermediate risk (p = 0.018), and high vs intermediate risk (p = 0.010), discriminating high risk from intermediate/low risk with an optimal threshold of 15% (sensitivity 100%, specificity 83%). Left ventricular (LV) end-diastolic volume was decreased in patients with severe uncoupling (p = 0.035 vs no/mild uncoupling). CONCLUSIONS: Early RV-PA uncoupling is associated with reduced longitudinal function, whereas advanced RV-PA uncoupling is associated with reduced anteroposterior movement and LV preload, all in a risk-related fashion. CLINICALTRIALS: GOV: NCT04663217.

Neuromuscular fatigability of plantar flexors following continuous and intermittent contractions.

The purpose of this study is to investigate if a continuous muscle contraction (CON) is more fatiguing than an intermittent exercise (INT) performed until task failure. To get a more comprehensive picture of neuromuscular fatigability, in addition to the commonly used maximal voluntary contraction (MVC), we assessed the maximal torque sustainability (i.e., the ability to maintain a high level of torque for 1 min). Fourteen subjects performed a plantar flexors MVC of 1-min duration (MVC1-MIN) before and after CON or INT contractions at 40% MVC until task failure. Despite a greater torque-time integral for the INT task, a similar MVC reduction was found after both exercises. On the contrary, a greater torque loss during the MVC1-MIN was observed after the CON exercise and it was positively correlated to the mean exercise torque. These results reveal that, for exercises performed until exhaustion, the contraction pattern (i.e., CON vs. INT) affects the ability to maintain a high level of torque, but does not influence the maximal torque production capacity. Thus, we demonstrate that maximal torque production and sustainability are two distinct and complementary characteristics of neuromuscular fatigability. Consequently, when considering both capacities, it results that, an exhausting CON contraction is more fatiguing than an exhausting INT effort. This highlights the importance of simultaneously evaluating both capacities when exploring neuromuscular fatigability.NEW & NOTEWORTHY This study provides new information about the influence of the contraction pattern (i.e., continuous and intermittent) on the development of neuromuscular fatigability when exercise is performed until exhaustion. Maximal torque production is similarly reduced by both exercises, whereas maximal torque sustainability is impaired only after the continuous exercise. To evaluate neuromuscular fatigability, we then recommend using a sustained maximal voluntary contraction since this measure allows to concurrently collect information on complementary aspects of neuromuscular fatigability.

Prediction of uterine dehiscence via machine learning by using lower uterine segment thickness and clinical features.

BACKGROUND: With the global increase of cesarean delivery rates, the long-term effects of cesarean delivery have started to become clearer. One of the most prominent complications of cesarean delivery in recurrent pregnancies is uterine rupture. Assessing the risk of uterine rupture by accurately predicting dehiscence is very important to prevent untimely operations and/or maternal and fetal complications. OBJECTIVE: This study aimed to assess whether machine learning can be used to predict uterine dehiscence by using patients' ultrasonographic findings, clinical findings, and demographic data as features. Hence, we investigated a potential method for preventing uterine rupture and its maternal and fetal complications. STUDY DESIGN: The study was conducted on 317 patients with term (>37 weeks' gestation) singleton pregnancies and no medical complications or medications that may affect uterine wound healing. Demographics, body mass indices, smoking and drinking habits, clinical features, past pregnancies, number and history of abortions, interdelivery period, gestational week, number of previous cesarean deliveries, fetal presentation, fetal weight, tocography data, transabdominal ultrasonographic measurement of lower uterine segment full thickness and myometrium thickness, and lower uterine segment findings during cesarean delivery were collected and analyzed using machine learning techniques. Logistic regression, multilayer perceptron, support vector machine, random forest, and naive Bayes algorithms were used for classification. The dataset was evaluated using 10-fold cross-validation. Correct classification rate, F-score, Matthews correlation coefficient, precision-recall curve area, and receiver operating characteristic area were used as performance metrics. RESULTS: Among the machine learning techniques tested in this study, the naive Bayes algorithm showed the best predictive performance. Among the various combinations of features used for prediction, the essential features of parity, gravidity, tocographic contraction, cervical dilation, dilation and curettage, and sonographic thickness of lower uterine segment myometrium yielded the best results. The second-best performance was achieved with sonographic full thickness of lower uterine segment added to the base features. The base features alone could classify patients with 90.5% accuracy, whereas adding the myometrium measurement increased the classification performance by 5.1% to 95.6%. Adding the full thickness measurement to the base features raised the classification performance by 4.8% to 95.3% in terms of correct classification rate. CONCLUSION: The naive Bayes algorithm can correctly classify uterine dehiscence with a correct classification rate of 0.953, an F-score of 0.952, and a Matthews correlation coefficient value of 0.641. This result can be interpreted as indicating that by using clinical features and lower uterine segment ultrasonography findings, machine learning can be used to accurately predict uterine dehiscence.

A Mild Dyssynchronous Contraction Pattern Detected by SPECT Myocardial Perfusion Imaging Predicts Super-Response to Cardiac Resynchronization Therapy.

Background: Using single photon emission computed tomography myocardial perfusion imaging (SPECT MPI) with phase analysis (PA), we aimed to identify the predictive value of a new contraction pattern in cardiac resynchronization therapy (CRT) response. Methods: Left ventricular mechanical dyssynchrony (LVMD) was evaluated using SPECT MPI with PA in non-ischemic dilated cardiomyopathy (DCM) patients with left bundle branch block (LBBB) indicated for CRT. CRT super-response was defined as LV ejection fraction (EF) ≥50% or an absolute increase of LVEF >15%. The LV contraction was categorized as the mild dyssynchronous pattern when the phase standard deviation (PSD) ≤ 40.3° and phase histogram bandwidth (PBW) ≤ 111.9°, otherwise it was defined as severe dyssynchronous pattern which was further characterized as U-shaped, heterogeneous or homogenous pattern. Results: The final cohort comprised 74 patients, including 32 (43.2%) in mild dyssynchronous group, 17 (23%) in U-shaped group, 19 (25.7%) in heterogeneous group, and 6 (8.1%) in homogenous group. The mild dyssynchronous group had lower PSD and PBW than U-shaped, heterogeneous, and homogenous groups (P < 0.0001). Compared to patients with the heterogeneous pattern, the odds ratios (ORs) with 95% confidence intervals (CIs) for CRT super-response were 10.182(2.43-42.663), 12.8(2.545-64.372), and 2.667(0.327-21.773) for patients with mild dyssynchronous, U-shaped, and homogenous pattern, respectively. After multivariable adjustment, mild dyssynchronous group remained associated with increased CRT super-response (adjusted OR 5.709, 95% CI 1.152-28.293). Kaplan-Meier curves showed that mild dyssynchronous group demonstrated a better long-term prognosis. Conclusions: The mild dyssynchronous pattern in patients with DCM is associated with an increased CRT super-response and better long-term prognosis.

Left ventricular contraction patterns in Takotsubo Syndrome and their correlation with long-term clinical outcome.

BACKGROUND: Takotsubo Syndrome (TTS) is diagnosed in 1-2% of all patients presenting with acute coronary syndrome. Next to the typical apical manifestation, other locations of left ventricular contraction abnormality are possible, but their relationship to patient characteristics, clinical correlates as well as long-term outcome are poorly understood. METHODS & RESULTS: We retrospectively analyzed 126 patients presenting TTS. Cases were categorized according to left ventricular contraction abnormality patterns: typical apical pattern (71%, n = 89) vs. atypical patterns (29%, n = 37). Cases with typical TTS showed significantly higher levels of troponin I (3.12 ng/ml vs. 1.32 ng/ml, p = 0.013) and creatin kinase (CK) on admission (461 (±1207)U/l vs. 173 (±177) U/l, p = 0.03) as well as peak CK (973 (±2860)U/l vs. 301 (±328) U/l, p = 0.03) and more often ischemia related ECG changes (p = 0.02). Follow-up data was available for 85% of the patients. Median FU time was 4.4 years (IQR 1.4-7.7 years). All-cause mortality during follow-up was 39%, with no significant difference between patients with typical or atypical TTS (43% vs. 29%, p = 0.17). In multivariate logistic regression analysis, only anemia was predictive for long-term mortality (OR 3.93, 95%CI 1.02-2.08, p = 0.015). The majority of surviving patients (69%) reported good quality of life, even though only 56% reported being symptom-free. CONCLUSION: Patients with TTS have poor long-term prognosis with an overall mortality of 39.1% within 4 years and nearly half of all patients report persisting symptoms. Even though the apical contraction pattern is associated with higher elevation of serum markers for myocardial damage, it was not associated with higher long-term mortality.

Assessment of left ventricular contraction patterns using gated SPECT MPI to predict cardiac resynchronization therapy response.

BACKGROUND: The U-shaped left ventricular (LV) contraction pattern, identified by MRI or echocardiography, is associated with improved CRT response. Gated SPECT MPI can measure both myocardial viability and mechanical dyssynchrony in a single scan. The aim of this study is to examine the relationship of the LV contraction pattern and the response of CRT in patients with left bundle branch block (LBBB). METHODS: Fifty-eight patients who met CRT guidelines and who had pre-CRT MPI were enrolled. Myocardial segments with tracer uptake < 50% of maximum were considered as scar. The LV contraction pattern was considered as U-shaped or non-U-shaped (U-shaped has a block line in the direction of contraction propagation). CRT response was defined as an increase in left ventricular ejection fraction ≥ 5% after 6-month follow-up. RESULTS: Twenty-eight patients (48%) had a U-shaped contraction pattern and thirty patients (52%) had a non-U-shaped contraction pattern. The U-shaped group showed a significantly higher response rate than the non-U-shaped group (90% vs. 57%; P = 0.005). By univariate and multivariate logistic regression analysis, the U-shaped pattern was an independent predictor of CRT response. CONCLUSION: Non-invasive gated SPECT MPI can characterize LV mechanical contraction patterns. A U-shaped contraction pattern identified is associated with improved CRT response. This may prove useful for improved patient selection for CRT.