Ventricular-vascular interaction is central in the adaptation to cardiovascular disease. However, cardiomyopathy patients are predominantly monitored using cardiac biomarkers. The aim of this study is therefore to explore aortic function in dilated cardiomyopathy (DCM). Fourteen idiopathic DCM patients and 16 controls underwent cardiac magnetic resonance imaging, with aortic relative pressure derived using physics-based image processing and a virtual cohort utilized to assess the impact of cardiovascular properties on aortic behaviour. Subjects with reduced left ventricular systolic function had significantly reduced aortic relative pressure, increased aortic stiffness, and significantly delayed time-to-pressure peak duration. From the virtual cohort, aortic stiffness and aortic volumetric size were identified as key determinants of aortic relative pressure. As such, this study shows how advanced flow imaging and aortic hemodynamic evaluation could provide novel insights into the manifestation of DCM, with signs of both altered aortic structure and function derived in DCM using our proposed imaging protocol.

• Klíčová slova
• 4D flow MRI, Aortic hemodynamics, Aortic relative pressure, Aortic stiffness, Dilated cardiomyopathy,
• MeSH
• aorta diagnostické zobrazování   MeSH
• dilatační kardiomyopatie * MeSH
• funkce levé komory srdeční MeSH
• hemodynamika MeSH
• lidé MeSH
• magnetická rezonanční tomografie metody   MeSH
• srdeční komory MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

BACKGROUND: A biomechanical model of the heart can be used to incorporate multiple data sources (electrocardiography, imaging, invasive hemodynamics). The purpose of this study was to use this approach in a cohort of patients with tetralogy of Fallot after complete repair (rTOF) to assess comparative influences of residual right ventricular outflow tract obstruction (RVOTO) and pulmonary regurgitation on ventricular health. METHODS: Twenty patients with rTOF who underwent percutaneous pulmonary valve replacement (PVR) and cardiovascular magnetic resonance imaging were included in this retrospective study. Biomechanical models specific to individual patient and physiology (before and after PVR) were created and used to estimate the RV myocardial contractility. The ability of models to capture post-PVR changes of right ventricular (RV) end-diastolic volume (EDV) and effective flow in the pulmonary artery (Qeff) was also compared with expected values. RESULTS: RV contractility before PVR (mean 66 ± 16 kPa, mean ± standard deviation) was increased in patients with rTOF compared with normal RV (38-48 kPa) (P < 0.05). The contractility decreased significantly in all patients after PVR (P < 0.05). Patients with predominantly RVOTO demonstrated greater reduction in contractility (median decrease 35%) after PVR than those with predominant pulmonary regurgitation (median decrease 11%). The model simulated post-PVR decreased EDV for the majority and suggested an increase of Qeff-both in line with published data. CONCLUSIONS: This study used a biomechanical model to synthesize multiple clinical inputs and give an insight into RV health. Individualized modeling allows us to predict the RV response to PVR. Initial data suggest that residual RVOTO imposes greater ventricular work than isolated pulmonary regurgitation.

CONTEXTE :: Une modélisation biomécanique du cœur peut être utilisée pour intégrer des sources de données multiples (électrocardiographie, imagerie, hémodynamique invasive). Le but de cette étude était d’utiliser cette approche pour une cohorte de patients atteints de tétralogie de Fallot aprèsr réparation complète (TdFr) pour évaluer, au niveau du ventricule, les influences comparatives de la sténose résiduelle de la voie d’éjection du ventricule droit (SVEVD) et de la régurgitation pulmonaire. MÉTHODES :: Vingt patients atteints de TdFr ayant subi un remplacement percutane de la valve pulmonaire (RVP) et une imagerie par résonance magnétique cardiovasculaire ont été inclus dans cette étude rétrospective. Des modèles biomécaniques adaptés à chaque patient et à sa physiologie (avant et après le RVP) ont été créés et utilisés pour estimer la contractilité myocardique du ventricule droit (VD). La capacité des modèles à capturer les changements post-RVP du volume télédiastolique (VTD) du VD et du débit effectif dans l’artère pulmonaire (Qeff) a également été comparée aux valeurs attendues. RÉSULTATS :: La contractilité du VD avant le RVP (moyenne 66 ± 16 kPa, moyenne ± déviation standard)) était plus élevée chez les patients atteints de TdFr par rapport au VD normal (38–48 kPa) (P < 0,05). La contractilité a diminué de manière significative chez tous les patients après le RVP (P < 0,05). Les patients présentant une SVEVD prédominante ont montré une plus grande réduction de la contractilité (diminution médiane de 35 %) après le RVP que ceux présentant une régurgitation pulmonaire prédominante (diminution médiane de 11 %). Le modèle a simulé une diminution du VTD-VD après le RVP pour la majorité des patients et a suggéré une augmentation du Qeff, ce qui est conforme aux données publiées. CONCLUSIONS :: Cette étude a utilisé un modèle biomécanique pour synthétiser de multiples données cliniques et donner un aperçu de l’état de santé du VD. La modélisation individualisée nous permet de prédire la réponse du VD au RVP. Les premières données suggèrent que la SVEVD résiduelle impose un travail ventriculaire plus important que la régurgitation pulmonaire isolée.

• MeSH
• biologické modely * MeSH
• chirurgická náhrada chlopně metody   MeSH
• dospělí MeSH
• Fallotova tetralogie chirurgie   MeSH
• hemodynamika fyziologie   MeSH
• insuficience plicnice vrozené   diagnóza   chirurgie   MeSH
• kardiochirurgické výkony metody   MeSH
• lidé MeSH
• magnetická rezonance kinematografická MeSH
• mnohočetné abnormality * MeSH
• následné studie MeSH
• plicní chlopeň abnormality   diagnostické zobrazování   chirurgie   MeSH
• reoperace MeSH
• retrospektivní studie MeSH
• srdeční komory diagnostické zobrazování   patofyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• pozorovací studie MeSH
• práce podpořená grantem MeSH

Patients after surgical repair of Tetralogy of Fallot (rTOF) may suffer a decrease in left ventricular (LV) function. The aim of our study is to evaluate a novel method of assessing LV torsion in patients with rTOF, as an early indicator of systolic LV dysfunction. Motion tracking based on image registration regularized by the equilibrium gap principle, known as equilibrated warping, was employed to assess LV torsion. Seventy-six cases of rTOF and ten normal controls were included. The group of controls was assessed for reproducibility using both equilibrated warping and standard clinical tissue tracking software (CVI42, version 5.10.1, Calgary, Canada). Patients were dichotomized into two groups: normal vs. loss of torsion. Torsion by equilibrated warping was successfully obtained in 68 of 76 (89%) patients and 9 of 10 (90%) controls. For equilibrated warping, the intra- and interobserver coefficients of variation were 0.095 and 0.117, respectively, compared to 0.260 and 0.831 for tissue tracking by standard clinical software. The intra- and inter-observer intraclass correlation coefficients for equilibrated warping were 0.862 and 0.831, respectively, compared to 0.992 and 0.648 for tissue tracking. Loss of torsion was noted in 32 of the 68 (47%) patients with rTOF. There was no difference in LV or RV volumes or ejection fraction between these groups. The assessment of LV torsion by equilibrated warping is feasible and shows good reliability. Loss of torsion is common in patients with rTOF and its robust assessment might contribute into uncovering heart failure in an earlier stage.

• Klíčová slova
• Early-stage heart failure, Equilibrated warping, Motion tracking, Tetralogy of Fallot, Torsion, Twist,
• MeSH
• dítě MeSH
• dospělí MeSH
• dysfunkce levé srdeční komory diagnostické zobrazování   patofyziologie   MeSH
• Fallotova tetralogie chirurgie   MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• počítačové zpracování obrazu metody   MeSH
• pooperační komplikace diagnostické zobrazování   patofyziologie   MeSH
• předškolní dítě MeSH
• reprodukovatelnost výsledků MeSH
• retrospektivní studie MeSH
• studie případů a kontrol MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• kojenec MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• předškolní dítě MeSH
• Publikační typ
• časopisecké články MeSH

During general anesthesia (GA), direct analysis of arterial pressure or aortic flow waveforms may be inconclusive in complex situations. Patient-specific biomechanical models, based on data obtained during GA and capable to perform fast simulations of cardiac cycles, have the potential to augment hemodynamic monitoring. Such models allow to simulate Pressure-Volume (PV) loops and estimate functional indicators of cardiovascular (CV) system, e.g. ventricular-arterial coupling (Vva), cardiac efficiency (CE) or myocardial contractility, evolving throughout GA. In this prospective observational study, we created patient-specific biomechanical models of heart and vasculature of a reduced geometric complexity for n = 45 patients undergoing GA, while using transthoracic echocardiography and aortic pressure and flow signals acquired in the beginning of GA (baseline condition). If intraoperative hypotension (IOH) appeared, diluted norepinephrine (NOR) was administered and the model readjusted according to the measured aortic pressure and flow signals. Such patients were a posteriori assigned into a so-called hypotensive group. The accuracy of simulated mean aortic pressure (MAP) and stroke volume (SV) at baseline were in accordance with the guidelines for the validation of new devices or reference measurement methods in all patients. After NOR administration in the hypotensive group, the percentage of concordance with 10% exclusion zone between measurement and simulation was >95% for both MAP and SV. The modeling results showed a decreased Vva (0.64±0.37 vs 0.88±0.43; p = 0.039) and an increased CE (0.8±0.1 vs 0.73±0.11; p = 0.042) in hypotensive vs normotensive patients. Furthermore, Vva increased by 92±101%, CE decreased by 13±11% (p < 0.001 for both) and contractility increased by 14±11% (p = 0.002) in the hypotensive group post-NOR administration. In this work we demonstrated the application of fast-running patient-specific biophysical models to estimate PV loops and functional indicators of CV system using clinical data available during GA. The work paves the way for model-augmented hemodynamic monitoring at operating theatres or intensive care units to enhance the information on patient-specific physiology.

• MeSH
• algoritmy MeSH
• arteriální tlak fyziologie   MeSH
• biomechanika MeSH
• celková anestezie metody   MeSH
• hemodynamické monitorování metody   MeSH
• hypotenze farmakoterapie   patofyziologie   MeSH
• krevní tlak MeSH
• lidé středního věku MeSH
• lidé MeSH
• minutový srdeční výdej fyziologie   MeSH
• modely kardiovaskulární * MeSH
• noradrenalin aplikace a dávkování   MeSH
• ověření koncepční studie MeSH
• prospektivní studie MeSH
• tepový objem fyziologie   MeSH
• vazokonstriktory aplikace a dávkování   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• noradrenalin MeSH
• vazokonstriktory MeSH