reservoir function
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Author(s):  
Nidhal Bouchahda ◽  
Mohamed Yassine Kallala ◽  
Imen Zemni ◽  
Mejdi Ben Messaoud ◽  
Mehdi Boussaada ◽  
...  

2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
K Inoue ◽  
Y Nakao ◽  
M Saito ◽  
M Kinoshita ◽  
R Higaki ◽  
...  

Abstract Objective To investigate a mechanistic determinant of left atrial (LA) reservoir function in patients presenting left ventricular (LV) hypertrophy, and clarify diagnostic and prognostic values of LA reservoir strain in patients with cardiac amyloidosis (CA). Methods Three-hundred sixty patients (median age: 68 years, male gender: 65%) with left ventricular hypertrophy (LVH) assessed by echocardiography were retrospectively included. The LVH etiologies were diagnosed by any of biopsy, cardiac magnetic resonance imaging or 99mTc-PYP scintigraphy. LV segmental longitudinal strain was estimated from apical three views, and LA reservoir strain was measured from an apical 4-chamber view. Results The LVH etiologies were confirmed with CA in 81 patients, hypertensive heart disease in 87 patients, hypertrophic cardiomyopathy in 143 patients, and miscellaneous disorders in 49 patients. The median (25th, 75th percentile) value of LV ejection fraction was 59% (48–67). LV basal longitudinal strain and LA reservoir strain were significantly reduced in patients with CA compared with those with other etiologies; LV basal strain: 5.4% (3.9–8.7) vs. 11.9% (9.3–14.6), LA reservoir strain: 9.2% (6.3–12.3) vs. 17.5% (11.3–24.1), p<0.01 respectively. LV basal strain was significantly correlated with LA reservoir strain in patients with CA (r=0.57, p<0.01) and in those with other etiologies (r=0.45, p<0.01). The area under the receiver-operating characteristic curves of LA reservoir strain and E/e' (0.78 and 0.74) to identify CA etiology were significantly larger than that of LA volume index (0.62) (p<0.01). During the follow-up period (median 2.9 years), 53 patients experienced heart failure hospitalization. The Cox regression model including age, gender, LV ejection fraction, E/e' and LA reservoir strain showed that male gender (hazard ratio: 0.46, p=0.03), E/e' (hazard ratio: 1.04, p<0.01) and LA reservoir strain (hazard ratio: 0.94, p<0.01) independently predicted heart failure hospitalization. Conclusions The decrease of LV longitudinal shortening at cardiac base could worsen LA reservoir function especially in patients with CA. LA reservoir strain might be an alternative measure to identify CA etiology and have a predictive value of heart failure hospitalization in patients with LV hypertrophy. FUNDunding Acknowledgement Type of funding sources: None.


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
K Kupczynska ◽  
D Miskowiec ◽  
B Michalski ◽  
J D Kasprzak

Abstract Background Atrial fibrillation (AF) impairs cardiac mechanics and leads to adverse remodelling. Increased left atrial (LA) stiffness reflecting LA reservoir function and left ventricular (LV) filling pressure is one of the symptoms of LA remodelling. Purpose To analyse LA stiffness within 24 hours after successful electrical cardioversion and its prognostic value during 2-years follow-up. Methods Prospective study involved 71 patients with nonvalvular AF (mean age 64±13 years, 61% male). All patients underwent echo during 24 hours after conversion to sinus rhythm. We analysed standard echocardiographic and Doppler parameters. Using speckle-tracking method we assessed peak LA longitudinal strain in 4- and 2-chamber view. LA stiffness was calculated as the quotient of peak LA longitudinal strain (LA reservoir function) and mean E/E' ratio. The clinical endpoints were predefined as AF recurrence and cardiovascular hospitalization. Results Median time of current AF episode was 2 (IQR 0.4–5) months. Standard echo measurements revealed median of LV ejection fraction 55% (IQR 45–58) and median of LA volume indexed to body surface area 42 ml/m2 (IQR 34–51). During follow-up we noticed AF recurrence in 48 (68%) patients and cardiovascular hospitalization in 43 (61%) patients. Median time-to-event was 2.4 (IQR 1 to 6.9) and 7 (IQR 2.1–11) months, respectively. Receiver operating characteristic curve analysis revealed that LA stiffness >0.53 (AUC=0.821; p<0.0001) and >0.95 (AUC=0.788; p<0.0001) were the optimal cut-off values for predicting AF recurrence and cardiovascular hospitalization. Figure presents Kaplan-Meier survival analysis for AF recurrence (A) and for hospitalization (B). Moreover LA stiffness remain statistically significant in multivariate Cox regression analysis even after adjustment for betablockers, antiarrhythmic drugs, coronary artery disease, heart failure and mitral regurgitation. Relative risk was 1.51 (95% CI 1.09–2.09), p=0.01 for AF recurrence and 1.49 (95% CI 1.05–2.13) for cardiovascular hospitalization. Conclusions Speckle tracking-derived LA stiffness assessed early after the restoration of sinus rhythm independently predicts AF recurrence and cardiovascular hospitalization. FUNDunding Acknowledgement Type of funding sources: None.


2021 ◽  
Vol 42 (Supplement_1) ◽  
Author(s):  
N Bouchahda ◽  
Y Kallala ◽  
T Hasnaoui ◽  
H Ibn Haj Amor ◽  
G Sassi ◽  
...  

Abstract Introduction Rheumatic mitral stenosis (MS) is still frequent in low income countries. Unlike the other left sided valvular heart diseases, symptoms' occurrence is still not well understood. Previous attempts to correlate mitral valve area (MVA), pulmonary hypertension and even mitral valve stenosis severity scores with symptoms' severity have failed to establish any strong relationship. Recent advances in the characterization of the left atrium (LA) function by echocardiographic strain technique, yielded a new understanding of symptoms genesis in MS. Purpose To assess the correlation between LA reservoir function determined by two-dimensional (2D) Speckle Tracking Echocardiography (STE) and New York Heart Association (NYHA) functional status in patients with MS. Methods We prospectively performed comprehensive 2D trans thoracic echocardiography (TTE) in patients with rheumatic MS. Echocardiographic parameters, such as indexed LA volume, trans mitral mean gradient, maximal trans tricuspid velocity (MTTV), valve area using planimetry and pressure half time (PHT) were recorded. All doppler parameters are expressed as a mean of at least three measurements. LA global strain curve and peak reservoir strain value were then obtained on a four-chamber view. NYHA functional status was assessed just before performing the echo procedure. Results We enrolled 186 patients with rheumatic MS, with a mean age of 50.55±12.07 years. 20 patients were excluded from the study because of the presence of impaired systolic LV function (n=12), severe mitral regurgitation (n=7) or severe aortic regurgitation (n=1). A total of 69.4% of our cohort were female (n=129), 56.2% (n=104) had a history of percutaneous transvenous mitral commissurotomy (PTMC), 59.9% had permanent atrial fibrillation (n=109). The mean MVA was 1.40±0.47 cm2, PHT derived Area was 1.47±0.52 cm2, mean gradient was 10.72±5.82 mmHg, mean indexed LA volume was 80.70±45.34 ml/m2 and mean MTTV was (3.09±0.62m/s). 75 patients (39.9%) were in NYHA III or IV functional class. Mean LA reservoir strain value was 11.08±7.76%. Comparing the group in NYHA III or IV functional class with the group NYHA I or II functional class, there was no statistically significant difference in mean MVA by planimetry or PHT, nor in mean gradient, MMTV or indexed LA volume. Interestingly, the NYHA III or IV functional status group had a significantly lower mean LA reservoir strain value compared to the NYHA I or II functional status group (8.94±5.57% vs 11.92±8.31%, p=0.011). Even in mild MS patients with a planimetry MVA ≥1.5cm2 (n=65), a significantly lower mean LA reservoir strain value was found in NYHA III or IV group compared to the NYHA I or II group (15.08±10.09% vs 9.76±4.35%, p=0.05). Conclusion LA reservoir function is highly correlated to the severity of symptoms in rheumatic MS. FUNDunding Acknowledgement Type of funding sources: None.


2021 ◽  
Vol 22 (Supplement_2) ◽  
Author(s):  
O Deal ◽  
J Rayner ◽  
A Stracquadanio ◽  
R Wijesurendra ◽  
S Neubauer ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): BHF & NIHR BRC Introduction Obesity is strongly associated with increased risk of heart failure and ischaemic stroke independently of associated co-morbidities. Left atrial (LA) reservoir dysfunction, a marker of atrial distensibility and compliance, is an early pathophysiological change which precedes the onset of cardiovascular disease in patients with obesity. It is unclear whether a weight loss intervention may be sufficient to reverse LA reservoir dysfunction. Purpose To longitudinally assess whether a weight loss intervention normalizes LA reservoir function by cardiac magnetic resonance (CMR) feature-tracking in patients with obesity and only subclinical cardiovascular disease and compared this age and sex matched non-obese normal weight controls. Methods A total of 45 patients with severe obese (age = 45 ± 11 years, body mass index = 39.1 ± 6.7 kg/m2, 51 ± 18 kg of excess body weight [EBW], 67% female) underwent CMR for quantification of LA and left ventricular (LV) size and function before and a median of 373 days following weight loss intervention. Weight loss was achieved by means of a very-low calorie diet (N = 28; 800 kcal/day) or by bariatric surgery (N = 17). A total of N = 27 non-obese healthy controls (age = 41 ± 12 years, body mass index = 22.3 ± 2.4 kg/m2, 75% female) underwent the same CMR protocol once. Results At baseline, patients with obesity displayed signs of atrial myopathy with increased LA volume and reduced LA reservoir function as compared to normal-weight controls (both P < 0.05, Figure 1) alongside increased LV mass and hyper-normal LV ejection fraction [LVEF] (both p < 0.01). As expected, weight loss led to a significant reduction of LA volume and LV mass with normalization of LVEF regardless of the degree of weight loss achieved (all P < 0.05, Figure 2). By contrast, only a large weight loss (>46.6% EBW, in red in Figure 2) was sufficient to improve and normalize the LA reservoir function (P < 0.05, Figure 2).  On the other hand, moderate or milder weight loss (in orange and red) had no significant effect on LA reservoir function (both P > 0.05). Conclusion Successful weight loss can completely revert early LA myopathic phenotype in obese patients without known cardiovascular disease although this can be achieved only with larger weight loss targets.


2021 ◽  
Vol 22 (Supplement_2) ◽  
Author(s):  
L Ferri ◽  
S Pica ◽  
L Tondi ◽  
A Camporeale ◽  
R Arosio ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. Background Increasing evidence suggests that left atrial (LA) deformation is a sensitive marker of diastolic dysfunction in hypertrophic phenotypes. However, there is little data about the impact of hypertension on LA function; furthermore, LA deformation in hypertensive heart disease (HHD) and hypertrophic cardiomyopathy (HCM) has not been compared yet.  Purpose The aim of this study is to compare atrial dimensions and function, evaluated by cardiovascular magnetic resonance feature tracking (CMR-FT) in patients with HHD, HCM and healthy subjects (HS). Methods 67 patients (20 HHD, 27 HCM, 20 HS) underwent CMR and were included in the study. Patients were matched for age, sex and BSA; HHD and HCM were also comparable for LV mass index and ejection fraction (EF). CMR-FT atrial strain analysis was performed using Qstrain, Medis software to obtain i) LA conduit function, ii) LA booster pump function), iii) LA reservoir function, iv) LA volumes and EF. Tissue Doppler echocardiography was used to assess diastolic function, including E/e’. LA stiffness was calculated as the ratio between E/e’ and LA reservoir. Both focal and interstitial myocardial fibrosis were assessed with LGE and extracellular volume (ECV) quantification.  Results HHD and HCM showed impaired LA reservoir, conduit function and higher LA volumes vs HS (reservoir: 28 ± 11% and 28 ± 13% vs 41 ± 17%; conduit: 13 ± 7% and 13 ± 7% vs 22 ± 11%; LAESV: 76 ± 21 and 87 ± 22 vs 57 ± 19 ml respectively; all p ≤ 0.03). HHD and HCM were comparable for bi-ventricular morpho-functional parameters and ECV. HHD showed lower E/e’ values (8 ± 2 vs 16 ± 7, p = 0.002) and LA stiffness (0.23 ± 0.3 vs 0.74 ± 0.6, p 0.03), LA dimensions (LA area 13 ± 3 vs 16 ± 3 cm2/m2, p = 0.02 , LAESVi 41 ± 12 vs 48 ± 11 ml/m2, p = 0.05) and LGE extent (1 ± 2% vs 5 ± 5%, p = 0.001) as compared to HCM. Interestingly, HHD revealed a comparable reduced LA reservoir and conduit function (all p = 0.9) vs HCM.  In HHD patients LA reservoir function was correlated with E/e’ (r -0.8, p = 0.02), but not in HCM. Conversely, LA reservoir function was correlated with LV mass index in HCM (r -0.5, p < 0.01).  Conclusions HHD patients showed a similar and significant impairment of LA function, with lower LA dimensions and E/e’ compared to HCM with similar LV mass index and preserved function. CMR-FT atrial strain analysis could represent a useful tool for HHD management, able to detect diastolic dysfunction (and/or atrial dysfunction) earlier than traditional markers. Further studies are needed to explore the relationship of LA deformation to heart failure symptoms and atrial fibrillation occurrence and potential changes related to response to therapy.


2021 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
K Dokuni ◽  
K Matsumoto ◽  
K Tatsumi ◽  
A Shono ◽  
M Suzuki ◽  
...  

Abstract Funding Acknowledgements Type of funding sources: None. Background The structural remodeling of the left atrium (LA) has been proposed as an important determinant of adverse outcomes in patients with heart failure (HF). However, little is known about the potential impact of LA mechanical dyssynchrony on its reservoir function and the prognosis of patients with HF. In addition, it has not been fully investigated whether cardiac resynchronization therapy (CRT) is also beneficial to LA function. Purposes The purposes of this study were to test whether left ventricular (LV) dyssynchrony may negatively affect LA synchronicity and reservoir function, and to assess whether residual LA dyssynchrony after CRT affects the prognosis in patients with HF with reduced ejection fraction (HFrEF). Methods This study included total of 90 subjects: 40 HFrEF with a wide-QRS complex (≧130 ms), 28 HFrEF with a narrow-QRS, and 22 age- and sex-matched normal controls. LA global longitudinal strain (LA-GLS) and LA dyssynchrony were quantified using speckle-tracking strain analysis. LA dyssynchrony was defined as the maximal difference of time-to-peak strain (LA time-diff). All wide-QRS HFrEF received CRT, and event-free survival was tracked for 24 months. Results At baseline, HFrEF patients showed significant LA remodeling coupled with the reduced LA reservoir function, as evidenced by larger LA volume index (LAVi: 46 ± 16 vs. 30 ± 14 mL/m², P < 0.01) and smaller LA-GLS (13.0 ± 4.8 vs. 30.6 ± 10.7%, P < 0.01). Of note was that, not only LV dyssynchrony (381 ± 178 vs. 177 ± 62 ms, P < 0.01) but also LA dyssynchrony (298 ± 136 vs. 186 ± 78 ms, P < 0.01) were significantly larger in patients with HFrEF compared to normal subjects and this applied even more to patients with a wide-QRS complex. All patients with a wide-QRS complex underwent CRT, and only responders exhibited the significant decrease in LA time-diff (from 338 ± 123 to 245 ± 141 ms, P < 0.05) and increase in LA-GLS (from 11.9 ± 4.7 to 19.6 ± 10.1%, P < 0.05) in parallel with the reduction in LAVi (from 48 ± 17 to 37 ± 18 mL/m², P < 0.05) at 6 months after CRT. Receiver operating characteristic curve analysis identified the optimal cut-off value of LA time-diff at 6 months after CRT as 202 ms (P < 0.05) and that of LA-GLS as 14.6% (P < 0.05) for predicting adverse cardiac events. The patients whose LA time-diff reduced <202 ms after CRT showed significantly favorable event-free survival than the others. Similarly, the patients whose LA-GLS improved >14.6% after CRT exhibited significantly favorable event-free survival than the others (P < 0.05, respectively). Of note was that, when the patients were restricted to CRT responders only, those who showed LA time-diff less than 202 ms at 6 months after CRT almost never experienced cardiac events (P < 0.05). Conclusions The improved LV coordination by CRT also resulted in resynchronization of discoordinated LA wall motion and a consecutive improvement of LA reservoir function, which ultimately lead to the favorable outcome for HFrEF patients with wide-QRS complex. Abstract Figure.


2021 ◽  
Vol 69 (5) ◽  
pp. 1068
Author(s):  
Srinivasan Senthilkumari ◽  
Manali Hazarika ◽  
NamperumalsamyVenkatesh Prajna

2020 ◽  
Vol 8 (1) ◽  
pp. 135-148
Author(s):  
Rani Sahfitri ◽  
Sugeng Prijono

The reservoir is one of the water sources that can be used for irrigation activities. PT. Great Giant Pineapple utilizes the reservoir function to provide water for irrigation activities. In an era that is increasingly developing now, many things can support success in the agricultural sector. Cropwat for window 8.0 application and ArcGis is one proof of technological advancements in this era. The results of this study were to determine the capacity of a reservoir by using two different methods namely bathymetry and DEM and to find out the performance of the reservoir used for irrigation activities based on pineapple plant water requirements.. This research is located in PT. Great Giant Pineapple, Terbanggi Besar, Lampung, conducted in October until November 2019. Based on the results of research that has been done, it is recommended to use the bathymetry method for reservoirs with water-filled conditions and using the DEM method for water-empty reservoirs and it is known that the performance of a reservoir will be affected by the amount of outflow and inflow that occurs in the reservoir and the large reservoir capacity.


Author(s):  
Supriyadi Supriyadi ◽  
Hizbulwathon Wirayuda ◽  
Khumaedi Khumaedi

<p class="AbstractEnglish"><strong>Abstract:</strong> The background of this research is the physical condition of the UNNES reservoir which needs attention after so many years of construction. This is an effort to maintain the sustainability of the reservoir function to capture rainwater so that it can be used in the dry season, and an effort to maintain the embung as one of the identities of UNNES as a university with a conservation perspective. In general, this study aims to determine the physical condition of the embung walls. This research was conducted at the edge of the reservoir at the State University of Semarang to determine the subsurface structure of the local location. The method used is resistivity resistivity by mapping or horizontally. The configuration used is the Wenner configuration. Based on the geoelectric survey, the resistivity value ranges from 2.7 Wm - 177 Wm, it can be seen that the most layers are sand and gravel. These two layers are easy to penetrate, allowing water in the embung to seep into the embung walls. Evidence of seepage is not visible on the wall of the embung, this is because the wall of the embung is in the ground, it does not appear on the ground.</p><p class="AbstrakIndonesia"><strong>Abstrak:</strong> Latar belakang penelitian ini adalah kondisi fisik embung UNNES yang perlu mendapat perhatian setelah sekian tahun dibangun. Hal ini sebagai upaya menjaga keberlangsungan fungsi embung untuk menangkap air curah hujan sehingga dapat dimanfaatkan pada musim kemarau, dan upaya mempertahankan embung sebagai salah satu identitas UNNES sebagai universitas yang berwawasan konservasi.   Penelitian ini secara umum bertujuan untuk mengetahui kondisi fisik dinding embung.Penelitian ini dilakukan di sisi pinggir embung Universitas Negeri Semarang untuk mengetahui struktur bawah permukaan lokasi setempat. Metode yang digunakan adalah resistitivitas tahanan jenis dengan cara mapping atau secara horisontal. Konfigurasi yang digunakan adalah konfigurasi Wenner. Berdasarkan survei geolistrik, nilai resistivitas berkisar antara 2,7 Wm - 177 Wm, terlihat secara keseluruhan lapisan yang paling banyak adalah lapisan pasir dan kerikil. Kedua lapisan ini mudah untuk ditembus sehingga memungkinkan air dalam embung rembes pada dinding embung. Bukti rembesan tidak nampak pada dinding embung, hal ini dikarenakan karena dinding embung berada di dalam tanah, tidak muncul di permukaan tanah.</p>


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