UNASSIGNED: Atrial septal defects (ASDs) lead to volume-loaded right ventricles (RVs). ASD closure does not always alleviate symptoms or improve exercise capacity, which is possibly explained by impaired left ventricular (LV) haemodynamics. This study evaluated the effect of ASD closure in children using non-invasive LV pressure-volume (PV) loops derived from cardiac magnetic resonance (CMR) imaging and brachial blood pressure, compared with controls.
UNASSIGNED: Twenty-three children with ASD underwent CMR, and 17 of them were re-examined 7 (6-9) months after ASD closure. Twelve controls were included. Haemodynamic variables were derived from PV loops by time-resolved LV volumes and brachial blood pressure. After ASD closure, LV volume increased [76 (70-86) vs. 63 (57-70) mL/m2, P = 0.0001]; however, it was still smaller than in controls [76 (70-86) vs. 82 (78-89) mL/m2, P = 0.048]. Compared with controls, children with ASD had higher contractility [2.6 (2.1-3.3) vs. 1.7 (1.5-2.2) mmHg/mL, P = 0.0076] and arterial elastance [2.1 (1.4-3.1) vs. 1.4 (1.2-2.0) mmHg/mL, P = 0.034]. After ASD closure, both contractility [2.0 (1.4-2.5) mmHg/mL, P = 0.0001] and arterial elastance [1.4 (1.3-2.0) mmHg/mL, P = 0.0002] decreased.
UNASSIGNED: Despite the left-to-right atrial shunt that leads to low LV filling and RV enlargement, the LV remains efficient and there is no evidence of impaired LV haemodynamics in children. Closure of ASD at young age while the ventricle is compliant is thus beneficial for LV function. LV volumes, however, remain small after ASD closure, which may impact long-term cardiovascular risk and exercise performance.

OBJECTIVE: To develop a reconstruction method for highly accelerated cardiac cine MRI with high spatiotemporal resolution and low temporal blurring, and to demonstrate accurate estimation of ventricular volumes and myocardial strain in healthy subjects and in patients.
METHODS: The proposed method, called CineVN, employs a spatiotemporal Variational Network combined with conjugate gradient descent for optimized data consistency and improved image quality. The method is first evaluated on retrospectively undersampled cine MRI data in terms of image quality. Then, prospectively accelerated data are acquired in 18 healthy subjects both segmented over two heartbeats per slice as well as in real time with 1.6 mm isotropic resolution. Ventricular volumes and strain parameters are computed and compared to a compressed sensing reconstruction and to a conventional reference cine MRI acquisition. Lastly, the method is demonstrated in 46 patients and ventricular volumes and strain parameters are evaluated.
RESULTS: CineVN outperformed compressed sensing in image quality metrics on retrospectively undersampled data. Functional parameters and myocardial strain were the most accurate for CineVN compared to two state-of-the-art compressed sensing methods.
CONCLUSIONS: Deep learning-based reconstruction using our proposed method enables accurate evaluation of cardiac function in real-time cine MRI with high spatiotemporal resolution. This has the potential to improve cardiac imaging particularly for patients with arrhythmia or impaired breath-hold capability.

OBJECTIVE: The need for permanent pacemaker (PPM) for iatrogenic atrioventricular block (AVB) after congenital heart surgery is about 1%. We aim to evaluate the long-term outcomes of patients with PPM for iatrogenic AVB and compare them to patients with an optimal repair (trivial/no residua)- Residual Lesion Score (RLS) Class-1 repair without PPM need.
METHODS: We reviewed 183 patients discharged with PPM for iatrogenic AVB from 2011 to 2022. Patients who survived to discharge with >30 days of follow-up were matched 1:1 with a cohort of RLS Class-1 patients based on fundamental diagnosis and primary procedure.
RESULTS: Median age at PPM placement was 1.4 years (IQR: 4.3 months - 3.9 years). The cumulative incidence of moderate or greater ventricular dysfunction at 1 year and 5 years was 11% and 18% in PPM patients, respectively, compared to 3% and 7% in RLS Class-1 patients (subdistribution HR, 2.6; 95% CI, 1.2-6.1; P =0.022). Independently, PPM patients with hypoplastic left heart syndrome (P =0.027) and who had undergone STAT Mortality Category 5 procedures (P =0.033) were at higher risk of ventricular dysfunction. Transplant-free survival at 1 year and 5 years was 94% and 89% in PPM patients, respectively, compared to 98% and 97% in RLS Class-1 patients (P =0.044). Additionally, PPM patients with palliated circulation had significantly lower transplant-free survival (P <0.001).
CONCLUSIONS: Compared to patients with an optimal repair without PPM, patients with PPM for iatrogenic AVB are at higher risk of developing moderate or greater ventricular dysfunction and have lower transplant-free survival.

2\'-deoxy-ATP (dATP) improves cardiac function by increasing the rate of crossbridge cycling and Ca[Formula: see text] transient decay. However, the mechanisms of these effects and how therapeutic responses to dATP are achieved when dATP is only a small fraction of the total ATP pool remain poorly understood. Here, we used a multiscale computational modeling approach to analyze the mechanisms by which dATP improves ventricular function. We integrated atomistic simulations of prepowerstroke myosin and actomyosin association, filament-scale Markov state modeling of sarcomere mechanics, cell-scale analysis of myocyte Ca[Formula: see text] dynamics and contraction, organ-scale modeling of biventricular mechanoenergetics, and systems level modeling of circulatory dynamics. Molecular and Brownian dynamics simulations showed that dATP increases the actomyosin association rate by 1.9 fold. Markov state models predicted that dATP increases the pool of myosin heads available for crossbridge cycling, increasing steady-state force development at low dATP fractions by 1.3 fold due to mechanosensing and nearest-neighbor cooperativity. This was found to be the dominant mechanism by which small amounts of dATP can improve contractile function at myofilament to organ scales. Together with faster myocyte Ca[Formula: see text] handling, this led to improved ventricular contractility, especially in a failing heart model in which dATP increased ejection fraction by 16% and the energy efficiency of cardiac contraction by 1%. This work represents a complete multiscale model analysis of a small molecule myosin modulator from single molecule to organ system biophysics and elucidates how the molecular mechanisms of dATP may improve cardiovascular function in heart failure with reduced ejection fraction.

BACKGROUND: Artificial intelligence-enhanced electrocardiogram (AI-ECG) analysis shows promise to detect biventricular pathophysiology. However, AI-ECG analysis remains underexplored in congenital heart disease (CHD).
OBJECTIVE: The purpose of this study was to develop and externally validate an AI-ECG model to predict cardiovascular magnetic resonance (CMR)-defined biventricular dysfunction/dilation in patients with CHD.
METHODS: We trained (80%) and tested (20%) a convolutional neural network on paired ECG-CMRs (≤30 days apart) from patients with and without CHD to detect left ventricular (LV) dysfunction (ejection fraction ≤40%), RV dysfunction (ejection fraction ≤35%), and LV and RV dilation (end-diastolic volume z-score ≥4). Performance was assessed during internal testing and external validation on an outside health care system using area under receiver-operating curve (AUROC) and area under precision recall curve.
RESULTS: The internal and external cohorts comprised 8,584 ECG-CMR pairs (n = 4,941; median CMR age 20.7 years) and 909 ECG-CMR pairs (n = 746; median CMR age 25.4 years), respectively. Model performance was similar for internal testing (AUROC: LV dysfunction 0.87; LV dilation 0.86; RV dysfunction 0.88; RV dilation 0.81) and external validation (AUROC: LV dysfunction 0.89; LV dilation 0.83; RV dysfunction 0.82; RV dilation 0.80). Model performance was lowest in functionally single ventricle patients. Tetralogy of Fallot patients predicted to be at high risk of ventricular dysfunction had lower survival (P < 0.001). Model explainability via saliency mapping revealed that lateral precordial leads influence all outcome predictions, with high-risk features including QRS widening and T-wave inversions for RV dysfunction/dilation.
CONCLUSIONS: AI-ECG shows promise to predict biventricular dysfunction/dilation, which may help inform CMR timing in CHD.

BACKGROUND: Iron deficiency anemia (IDA) is a common health problem worldwide. The objective of this study was to noninvasively and quantitatively evaluate early changes in left ventricular systolic function in patients with IDA using the left ventricular press-strain loop (LV-PSL).
METHODS: Sixty-two patients with IDA were selected and divided into two groups based on hemoglobin (Hb) concentration: Group B with Hb > 9 g/dL and group C with 6 g/dL < Hb < 9 g/dL. Thirty-three healthy individuals were used as the control (Group A). The global longitudinal strain (GLS), global work index (GWI), global constructive work (GCW), global waste work (GWW), global work efficiency (GWE) were derived using LV-PSL analysis. Receiver operating characteristic (ROC) curves were constructed for MW parameters to detect abnormal left ventricular systolic function in IDA patients.
RESULTS: Compared to group A, GWI and GCW were reduced in group B (both P < 0.01). Compared with groups B and A, GLS, GWI, GCW and GWE, and E/A were all diminished, and GWW, LVEDV, LVESV, and E/mean e\' were all increased in group C (all P < 0.01). GLS was positively correlated with GWI, GCW, and GWE (r = 0.679, 0.681, and 0.447, all P < 0.01), and negatively associated with GWW (r = - 0.411, all P < 0.01). For GWI, area under the ROC curve (AUROC) was 0.783. The optimal GWI threshold for detecting abnormal LV systolic function in IDA was1763 mmHg%, with sensitivity of 0.71 and specificity of 0.78.
CONCLUSIONS: LV-PSL allows noninvasive quantitative assessment of early impaired LV systolic function in IDA patients with preserved LV ejection fraction, and GWI has high sensitivity and specificity compared with other parameters.

UNASSIGNED: Complete bundle branch block in individuals without structural heart disease is known as isolated complete bundle branch block. Isolated complete left bundle branch block (CLBBB) is correlated with ventricular dysfunction secondary to dyssynchrony; however, few studies have investigated isolated complete right bundle branch block (CRBBB), which was previously considered benign but was recently found to be associated with adverse cardiovascular outcomes. This study aimed to evaluate cardiac mechanical synchrony, and systolic and diastolic function in patients with isolated CRBBB and compare cardiac synchrony and function to patients with isolated CLBBB.
UNASSIGNED: This cross-sectional study was conducted at The First Hospital of China Medical University in Shenyang, China, from 2020 to 2021. A total of 44 isolated CRBBB patients, 44 isolated CLBBB patients, and 42 healthy subjects were enrolled in the study. Transthoracic echocardiography was performed in all subjects. Synchrony parameters, including the mechanical dispersion of the right ventricle [the standard deviation of time to the peak longitudinal strain of six right ventricular (RV) segments] and atrioventricular dyssynchrony parameter [the ratio of left ventricular (LV) diastolic filling time to the time interval between two adjacent R waves (RR interval) measured by tissue Doppler imaging]. RV and LV function were assessed by the global longitudinal strain (GLS) of six RV segments and 18 LV segments, and the ratio of the peak early diastolic flow velocity to annular velocity (E/e\') of the tricuspid valve and mitral valve. Statistical analyses were performed, including an analysis of variance, Pearson correlation analysis, and linear regression analysis.
UNASSIGNED: Compared with the healthy subjects, the mechanical dispersion of the right ventricle was significantly increased, and ventricular function was impaired as evidenced by the decreased RV GLS and LV GLS, and the increased E/e\' of the tricuspid valve and mitral valve in the isolated CRBBB patients (all P<0.001). Moreover, compared with the isolated CLBBB patients, the mechanical dispersion of the right ventricle and E/e\' of the tricuspid valve were increased, and RV GLS was significantly reduced in the isolated CRBBB patients (all P<0.001). Mechanical dispersion of the right ventricle was independently associated with RV GLS [coefficient, 0.13; 95% confidence interval (CI): 0.004-0.26; P=0.04] in the isolated CRBBB patients. RV GLS (coefficient, 0.10; 95% CI: 0.01-0.20; P=0.03) and the ratio of the LV diastolic filling time to the RR interval measured (coefficient, -0.30; 95% CI: -0.53 to -0.07; P=0.01) were independent factors of LV GLS.
UNASSIGNED: The isolated CRBBB patients had impaired cardiac mechanical synchrony and ventricular function, and more decreased RV synchrony and function than the isolated CLBBB patients. Right intraventricular synchrony was independently associated with RV systolic dysfunction in patients with isolated CRBBB. Atrioventricular synchrony and RV systolic function were independently associated with the LV systolic function. Therefore, comprehensive evaluations of echocardiography results and close monitoring is required for isolated CRBBB patients.

Left ventricular (LV) longitudinal function is mechanically coupled to the elasticity of the ascending aorta (AA). The pathophysiologic link between a stiff AA and reduced longitudinal strain and the subsequent deterioration in longitudinal LV systolic function is likely relevant in heart failure with preserved ejection fraction (HFpEF). The proposed therapeutic effect of freeing the LV apex and allowing for LV inverse longitudinal shortening was studied in silico utilizing the Living Left Heart Human Model (Dassault Systémes Simulia Corporation). LV function was evaluated in a model with (A) an elastic AA, (B) a stiff AA, and (C) a stiff AA with a free LV apex. The cardiac model simulation demonstrated that freeing the apex caused inverse LV longitudinal shortening that could abolish the deleterious mechanical effect of a stiff AA on LV function. A stiff AA and impairment of the LV longitudinal strain are common in patients with HFpEF. The hypothesis-generating model strongly suggests that freeing the apex and inverse longitudinal shortening may improve LV function in HFpEF patients with a stiff AA.

Pulmonary hypertension (PH) is rarely a cause of syncope. We highlight an unusual presentation of pulmonary hypertension where management was a veritable challenge. We present a case report of a 35-year-old female with a history of stage 2 hypertension, polycystic ovarian syndrome, and obesity who presented to the hospital with a six-month history of progressive shortness of breath, lower extremity swelling, and recurrent syncope. Further evaluation with transthoracic echocardiography showed features consistent with severe pulmonary hypertension. This untreated severe pulmonary hypertension culminated in cardiogenic shock due to right ventricular (RV) failure. Successful care in this patient population entails preventing the acute downward spiral of decompensated right ventricular failure.

The role of preoperative cardiac computed tomography (CT) in neonates with pulmonary atresia and intact ventricular septum (PA-IVS) remains unclear. This study was aimed to elaborate the role of preoperative CT-derived anatomical and functional findings in planning treatment strategies in neonates with PA-IVS. The presence of ventriculocoronary arterial connections was evaluated by CT. CT-derived ventricular volumetric parameters were compared and correlated with echocardiographic tricuspid valve (TV) z-score in 12 neonates with PA-IVS. Cardiac CT and echocardiographic findings were compared between definite surgical types (median follow-up, 4 years). Ventriculocoronary arterial connections were identified with CT in 58.3% of cases (7/12) and associated with higher incidence of Fontan procedure (42.9%, 3/7) and high mortality (28.6%, 2/7). The CT-derived and echocardiographic TV z-scores exhibited a high correlation (R = 0.924, p < 0.001). The CT-derived right ventricle (RV) volume and RV-left ventricle volume ratio also displayed high correlations (R = 0.875 and 0.867, respectively; p < 0.001) with echocardiographic TV z-score. More positive echocardiographic TV z-score, high CT-derived RV end-diastolic volume and RV-left ventricle volume ratio, and low CT-derived left ventricular end-diastolic volume were observed in biventricular surgery group (N = 2), compared to Fontan operation (N = 3) and 1.5 ventricular surgery (N = 3) groups, and mortality cases (N = 3). Preoperative CT-derived coronary artery anatomy and ventricular volumetric parameters may supplement treatment planning in neonates with PA-IVS especially when multifactorial decision including echocardiographic TV z-score is in a gray zone.W.