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espanolO objetivo deste trabalho e analisar os fatores hemodinamicos do escoamento numa fistula arteriovenosa (FAV). O modelo geometrico da FAV e obtido virtualmente a partir de uma tomografia computadorizada. No modelo matematico, que simula o fluxo da sangue na FAV, e considerado um fluido nao-Newtoniano, escoamento laminar, incompressivel e em regime transiente. O comportamento do fluxo na FAV e dado pela velocidade do sangue em cinco pontos correspondente a vazao massica em fase sistolica e em fase diastolica. A simulacao numerica do campo de velocidade na fase sistolica apresentou maior intensidade de recirculacoes axiais e radiais. A presenca de recirculacoes permite que elementos figurados se choquem excessivamente na parede do endotelio. EnglishThe objective of this study is to analyze the hemodynamic factors of flow in an arteriovenous fistula (AVF). The geometric model of the AVF is obtained virtually from a computed tomography. In the mathematical model, which simulates blood flow in the AVF, it is considered a non-Newtonian fluid, incompressible and transient laminar flow. The flow behavior in the AVF is given by the blood velocity in five points corresponding to the mass flow in the systolic phase and in the diastolic phase. The numerical simulation of the velocity field in the systolic phasepresented greater intensity of axial and radial recirculations. The presence of recirculations allows figurative elements to collide excessively in the wall of the endothelium

Objective Cerebral aneurysm growth often precedes rupture. Definite contributors to aneurysm growth have not been determined even by means of recently developed commercially available computational fluid dynamics (CFD) software. We developed an original CFD tool that can analyze data from time-of-flight magnetic resonance angiography (TOF-MRA) before growth in the growing aneurysms and investigate possible factors for aneurysm growth in the near future. Methods We retrospectively reviewed unruptured aneurysms that were treated at our institute because of aneurysm growth (growing group) between April 2013 and March 2017. Stable aneurysms that had demonstrated no growth for more than 5 years were selected (stable group). TOF-MRA data of these aneurysms were retrospectively converted to 3-dimensional vessel geometric data; 3 hemodynamic indices including streamline, wall shear stress (WSS), and oscillatory shear index were calculated by our original CFD tool using the lattice Boltzmann method to quantitatively compare the 2 groups. Results Six growing aneurysms and 6 stable aneurysms were analyzed. Of the 6 growing aneurysms, WSS on the focal aneurysmal sac increased temporally in the vicinity of the constant low WSS area at the peak systolic phase. By contrast, WSS did not increase during any part of the cardiac cycle in 3 of the 6 stable aneurysms. The peak values of WSS were significantly different between the 2 groups. Conclusions A focal increase in WSS in the peak systolic phase may be a risk factor for aneurysm enlargement in the near future.

Intracranial bruits (ICB) are faint, high-pitched, and mostly heard on the orbit in the systolic phase of the cardiovascular cycle. This report discusses a case of Listeria monocytogenes meningitis in a 17-month-old male patient in whom ICB were auscultated. ICB is thought to be caused by compression of blood vessels due to increased intracranial pressure and may serve as an additional sign supporting the diagnosis of meningitis. The present report contains video data on the ICB.

Background T1 mapping is emerging as a powerful tool in cardiac magnetic resonance (CMR) to evaluate diffuse fibrosis. However, right ventricular (RV) T1 mapping proves difficult due to the limited wall thickness in diastolic phase. Several studies focused on systolic T1 mapping, albeit only on the left ventricle (LV). Purpose To estimate intra- and inter-observer variability of native T1 (nT1) mapping of the RV, and its correlations with biventricular and pulmonary function in patients with congenital heart disease (CHD). Material and Methods In this retrospective, observational, cross-sectional study we evaluated 36 patients with CHD, having undergone CMR on a 1.5-T scanner. LV and RV functional evaluations were performed. A native modified look-locker inversion recovery short-axis sequence was acquired in the systolic phase. Intra- and inter-reader reproducibility were reported as complement to 100% of the ratio between coefficient of reproducibility and mean. Spearman ρ and Mann–Whitney U-test were used to compare distributions. Results Intra- and inter-reader reproducibility was 84% and 82%, respectively. Median nT1 was 1022 ms (interquartile range [IQR] 1108–972) for the RV and 947 ms (IQR 986–914) for the LV. Median RV–nT1 was 1016 ms (IQR 1090–1016) in patients with EDVI ≤100 mL/m2 and 1100 ms (IQR 1113–1100) in patients with EDVI >100 mL/m2 ( P = 0.049). A significant negative correlation was found between RV ejection fraction and RV–nT1 (ρ = −0.284, P = 0.046). Conclusion Systolic RV-nT1 showed a high reproducibility and a negative correlation with RV ejection fraction, potentially reflecting an adaptation of the RV myocardium to pulmonary valve/conduit (dys)-function.

Introduction: Systemic arterial hypertension is a disease that mainly affects women. Objective: This study aimed to verify the hypotensive effect and blood pressure reactivity in women submitted to a concurrent cross exercise (CC) session. Methods: Fifteen volunteers (54±3) performed aerobic exercise alternated with a series of weights exercises, for the analysis of blood pressure variation (by the oscillometric method) and pressure reactivity (by the Cold pressure test) before and after exercise. Results: The results demonstrated the occurrence of post-exercise hypotension in the systolic phase in the comparison between CC and C post-exercise (−11.65 mmHg). CC led to attenuation of 7mmHg and 4mmHg for SBP and DBP, respectively, in the blood pressure reactivity after one session. Conclusion: It is concluded that concurrent cross exercise ensures hypotension and positive reactivity of systolic blood pressure. Level of evidence II; Therapeutic studies-Investigating the results of treatment.

Evaluating the effects of heart cavity volume, presence and absence of perfusion defect, gender and type of study (stress and rest) on the difference of systolic parameters of myocardial perfusion scan in 16 and 8 framing gated SPECT imaging.Cardiac gated SPECT in both 16 and 8 framing simultaneously and both stress and rest phases at one-day protocol was performed for 50 patients. Data have been reconstructed by filter back projection (FBP) method and left ventricular (LV) systolic parameters were calculated by using QGS software. The effect of some factors such as LV cavity volume, presence and absence of perfusion defect, gender and type of study on data difference between 8 and 16 frames were evaluated.The differences in ejection fraction (EF), end-diastolic volume (EDV) and end-systolic volume (ESV) in both stress and rest were statistically significant. Difference in both framing was more in stress for EF and ESV, and was more in rest for EDV. Study type had a significant effect on differences in systolic parameters while gender had a significant effect on differences in EF and ESV in rest between both framings.In conclusion, results of this study revealed that difference of both 16 and 8 frames data in systolic phase were statistically significant and it seems that because of better efficiency of 16 frames, it cannot be replaced by 8 frames. Further well-designed studies are required to verify these findings.Amaç: Kalp boşluk hacmi, perfüzyon defekti varlığı veya yokluğu, cinsiyet ve inceleme tipinin (istirahat-stres) 16 ve 8 frame modeli ile gated SPECT görüntülemede miyokard perfüzyon sintigrafisi sistolik parametrelerindeki farklılık üzerindeki etkilerini incelemektir. Yöntem: Elli hastada eş zamanlı olarak hem 16 hem 8 frame hem stres hem dinlenme fazları ile tek-gün protokolü ile kardiyak gated SPECT uygulandı. Veriler geri filtreleme yansıması (FBP) yöntemi ile rekonstrükte edildi ve QGS yazılımı kullanılarak LV sistolik parametreleri hesaplandı. LV boşluk hacmi, perfüzyon defekti varlığı ya da yokluğu, cinsiyet ve inceleme tipi gibi bazı faktörlerin 16 ve 8 frame modeli ile gated SPECT görüntülemede miyokard perfüzyon sintigrafisi sistolik parametrelerindeki farklılık üzerindeki etkileri incelendi. Bulgular: EF, EDV ve ESV’de hem stres hem istirahattaki fark istatistik olarak anlamlı idi. Her iki frame ile EF, EDV ve ESV’de artmış fark sırasıyla stres, istirahat ve streste idi. İnceleme türünün sistolik parametreler üzerinde anlamlı etkisi vardı, benzer şekilde cinsiyetin istirahat halinde her iki bölme yöntemi arasında EF ve ESV farkı üzerinde anlamlı etkisi görüldü. Sonuç: Sonuç olarak, bu çalışma sonuçları hem 16 hem 8 frame ile elde edilen sistolik verinin istatistiksel olarak anlamlı olduğunu ortaya koymaktadır ve 16 frame modelinin daha etkin olması nedeniyle 8 frame ile değiştirilemeyeceğini öne sürmektedir. Bu bulguların ileride iyi planlanmış çalışmalar ile doğrulanması gerekmektedir.

The relationship between body fat depots and the left atrial (LA) dimensions has not been fully explored. Our objective is to determine if there is a relationship not only with total body fat depots, but specifically with regional fatty depots.It was an observational, retrospective study that included consecutive patients referred to our institution with an order to perform computed tomography angiography triggered by electrocardiogram for different clinical indications. Measurements of the LA were made in the systolic phase, using four and two cameras views.A total of 87 patients were included. The mean age was 66.4 ± 12.5 years; 67% were men. The LA volume indexed by the body surface area was 48.0 ± 16.6 cmIn this study, we did not identify significant relationships between LA dimensions and global or regional body fat depots.La relación entre los depósitos de grasa corporal y las dimensiones de la aurícula izquierda (AI) no ha sido del todo explorada. Nuestro objetivo es determinar si existe relación no solo con los depósitos de grasa corporal totales, sino específicamente con los depósitos grasos regionales.Estudio observacional, retrospectivo, que incluyó pacientes consecutivos remitidos a nuestra institución con orden de realización de angiotomografía computarizada toracoabdominal gatillada con electrocardiograma por distintas indicaciones clínicas. Las mediciones de la AI se realizaron en la fase sistólica, utilizando vistas de cuatro y dos cámaras.Se incluyeron un total de 87 pacientes. La edad media fue de 66.4 ± 12.5 años; un 67% de los sujetos fueron hombres. El volumen de la AI indexado por la superficie corporal fue de 48.0 ± 16.6 cmEn este estudio, no identificamos relaciones significativas entre las dimensiones de la AI y los depósitos de grasa corporal globales o regionales.

Utilizing numerical simulation, this study investigated the performance of aortic valves with abnormally thickened leaflets during the systolic phase of the cardiac cycle. The method used coupled computational fluid dynamics and finite element analysis simulations to solve flexible structures interaction with surrounding fluid flow in the valves. The valve model was developed with a valve height of 10 mm, a free edge angle of 0 degrees, a leaflet thickness of 0.2 mm and a valve radius of 23.5 mm. Different cases of valve diseases were considered, including cases involving one thickened leaflet and cases involving two thickened leaflets. In these studied cases, the thickness of the diseased leaflet or leaflets was thicker than that of a normal one by 50 %, 100 % and 150 %, respectively. High shear stresses were discovered during leaflets acceleration period along with big leaflets distortions for all six diseased valve models. The diseased valve with 150 % thicker leaflets experienced a shear stress of up to 98.6 Pa that could disrupt the functions of the valve and therefore lead to severe problems of the cardiovascular system.

Objectives This study aimed to elucidate the physiological feasibility of aortic valve neocuspidization (AVNeo) by comparing the aortic annulus dimensions between patients after AVNeo and patients with normal aortic valves. Methods From December 2010 to October 2017, we performed AVNeo for various aortic valve pathologies in 147 patients. Of these patients, the aortic annulus dimensions were measured in 25 patients who underwent AVNeo for aortic valve disease as follow-up examination and compared with those measured in 15 patients who had normal aortic valves. Measurements were recorded using electrocardiography-gated transthoracic echocardiography. Results No significant differences in the aortic annulus dimensions were observed between the patients who had undergone AVNeo and those who had normal aortic valves. In a cardiac cycle, the annulus area in the systolic phase was consistently larger than that in the diastolic phase, which was a physiological condition. Conclusions The movement of the aortic annulus after AVNeo is comparable with that of the aortic annulus of a normal aortic valve. Thus, AVNeo can be regarded as a more physiological operation in that it maintains the characteristics of the aortic valve similar to those of a normal aortic valve.

Author(s): Falahatpisheh, Ahmad; Rickers, Carsten; Gabbert, Dominik; Heng, Ee Ling; Stalder, Aurelien; Kramer, Hans-Heiner; Kilner, Philip J; Kheradvar, Arash | Abstract: PurposeTo determine whether neglecting the flow unsteadiness in simplified Bernoulli's equation significantly affects the pulmonary transvalvular pressure drop estimation.Materials and methods3.0T magnetic resonance imaging (MRI) 4D velocity mapping was performed on four healthy volunteers, seven patients with repaired tetralogy of Fallot, and thirteen patients with transposition of the great arteries repaired by arterial switch. Pulmonary transvalvular pressure drop was estimated based on two methods: General Bernoulli's Equation (GBE), ie, the most complete form; and Simplified Bernoulli's Equation (SBE), known as 4V(2) . More than 2300 individual pressure drop measurements were used to compare the simplified and the general Bernoulli's methods. A linear mixed-effects model was employed for statistical analyses, fully accounting for clustering of observations among the methods and systolic phases.ResultsThe simplified Bernoulli's method systematically underestimated the pressure drop compared to general Bernoulli's method during the entire systolic phase (P l 0.05), including the peak systole, where on average ΔpSBE/ΔpGBE=78%.ConclusionThe simplified Bernoulli method underestimated the pressure drop during all systolic phases in all the studied subjects. Therefore, it is necessary to take into account the flow unsteadiness for more accurate estimation of the pressure drop. J. Magn. Reson. Imaging 2016;43:1313-1319.

Author(s): Contijoch, Francisco; Witschey, Walter RT; Rogers, Kelly; Gorman, Joseph; Gorman, Robert C; Ferrari, Victor; Han, Yuchi | Abstract: PurposeTo evaluate the impact of end-diastolic (ED) and end-systolic (ES) cardiac phase selection methods, since task force recommendations have neither provided quantitative evidence nor explored errors introduced by clinical shortcuts.Materials and methodsMultislice, short-axis cine images were collected in 60 clinical patients on a 1.5T scanner. User-initialized active contour segmentation software quantified global left ventricular (LV) volume across all cardiac phases. Different approaches for selection of ED and ES phase were evaluated by quantification of temporal and volumetric errors.ResultsFor diastole, the mid-ventricular maximum slice volume coincided with maximum global volume in 82.1% of patients with ejection fraction (EF) ≥55% (P = 0.66) and 71.9% of patients with EF l55% (P = 0.28) and is an accurate approximation of maximum global volume while the first and last phases in a retrospectively electrocardiogram (ECG)-gated acquisition introduced differences in cardiac phase selection (P l 0.001) which led to large errors in measured volume in some patients (12.7 and 10.1 mL, respectively). For systole, post-systolic shortening occurred in a significantly higher number of patients with EF l55% (18.9%) compared to 3.6% of patients with EF ≥55% (P = 0.001), which differentially impacted end-systolic volume estimation.ConclusionFor end-diastolic phase selection, our results indicated that the use of the mid-ventricular slice volume maximum provided accurate volume estimates, while selection of the first or last cardiac phase introduced differences in measured volume. For end-systolic phase, patients with EF l55% had a higher prevalence of post-systolic shortening, which suggests aortic valve closure should be used to estimate end-systolic volume.

A mechanics–based analysis of data from three–dimensional speckle tracking echocardiography is proposed, aimed at investigating deformations in myocardium and at assessing shape and function of distinct strain lines corresponding to the principal strain lines of the cardiac tissue. The analysis is based on the application of a protocol of measurement of the endocardial and epicardial principal strain lines, which was already tested on simulated left ventricles. In contrast with similar studies, it is established that endocardial principal strain lines cannot be identified with any structural fibers, not even along the systolic phase and is suggested that it is due to the capacity of the endocardial surface to contrast the dilation of the left ventricle. A mechanics-based analysis of data from three-dimensional speckle tracking echocardiography is proposed, aimed at investigating deformations in myocardium and at assessing shape and function of distinct strain lines corresponding to the principal strain lines of the cardiac tissue. The analysis is based on the application of a protocol of measurement of the endocardial and epicardial principal strain lines, which was already tested on simulated left ventricles. In contrast with similar studies, it is established that endocardial principal strain lines cannot be identified with any structural fibers, not even along the systolic phase and is suggested that it is due to the capacity of the endocardial surface to contrast the dilation of the left ventricle.

Three-dimensional deformation analysis of human organs is very important from both diagnostic and therapeutic point of view. For example, comparing the deformation field in healthy and pathologic cardiac walls in the systolic phase allows to gather early and accurate information on the onset of heart diseases. MRI tagging is utilized in medicine to visualize with a great deal of detail the structure and morphology of tissues. The tagging process introduces a volumetric system of planes of reference similar to the process of introducing a grating in the 3-D moire method in transparent media. The paper will analyze the kinematics of 3-D deformation fields and the fundamental concepts involved in 3-D deformation analysis within the restrictions imposed by the MRI method thus providing solutions for the inherent shortcomings encountered in the MRI tagging technique.

d v w a AORTIC INSUFFICIENCY (AI) in patients after left ventricular assist device (LVAD) implantation is one of the nintended and potentially harmful consequences.1,2 Excessive LVAD flows, resulting in diminished and infrequent aortic valve (AV) opening, may facilitate AI progression and extend its duration to the systolic phase of the cardiac cycle.2,3 The igh temporal resolution of the echocardiographic M mode akes it very effective in monitoring the effects of LVAD speeds n AV function in real time. This case report describes the pathohysiology of AV leaflets akinesis and systolic aortic insufficiency n patients supported with continuous-flow LVAD and shows the rayscale and color M-mode AV surveillance in the perioperative ptimization of the LVAD setting.

Zusammenfassung Mit Hilfe des Phonokardiogrammes wurde eine Spaltung des I. Herztones beim Hund dargestellt. Die Herztonschreibung dieser Spaltung ist technisch schwierig, sie gelang bei 5 besonders ruhigen, schmalbrustigen Hunden mit dunner Thoraxwand. Bei ausgepragter respiratorischer Herzarrhythmie war das Spaltungsintervall verschieden lang. Wenn die beiden Tonteile dem Anspannungston und dem Austreibungston (Aortenoffnungston) entsprechen, ist das Intervall gleich der Druckanstiegszeit (DAZ). Die Ausmessung auch der anderen Systolenunterzeiten und der Vergleich ergibt, das mit zunehmender Lange der vorhergehenden Diastole die Umformungszeit (UZ) nicht verandert ist, wahrend die DAZ kurzer und die Austreibungszeit (S) langer ist. Der inspiratorischen Steigerung der Herzfrequenz mit ihren kurzen Diastolen folgt eine lange DAZ bzw. eine kurze S, der exspiratorischen Frequenzver-langsamung mit ihren langen Diastolen eine kurze DAZ bzw. eine lange S. Die Unterschiede sind statistisch gesichert. Da eine Sicherung der Mesergebnisse durch simultane Schreibung des gespaltenen I. HT und intrakardialer Drucke wegen methodischer Schwierigkeiten nicht moglich war, wurde zunachst die Ubereinstimmung der Meswerte aus der Tonteilung des I. Herztones mit denen aus EKG, PKG und Karotispulskurve, abgenommen mit einer Halsmanschette, statistisch gesichert. Zu dieser Messung kann man ohne weiteres simultan intrakardiale Drucke registrieren. Auch zwischen diesen beiden Methoden ergaben sich signifikant gleiche Werte. Uber diesen Beleg hinaus wurden auch andere Ursachen, z. B. die links- bzw. rechtsventrikulare oder beidseitige Entstehung der Tondoppelung ausgeschlossen. Krankhafte Veranderungen lagen nicht vor. Dazu wurden die Werte mit denen in der Literatur verglichen. Danach scheint die DAZ ein feiner Anzeiger fur hamodynamische Veranderungen zu sein. Summary Respiratory variations of the systolic phases of the canine heart With the help of a phonocardiogram, it was possible to record the doubling of the first heart sound in the dog. This was technically difficult but proved successful in five particularly passive narrow-chested dogs with a thin thoracic wall. With pronounced cardiac arrhythmia the interval between the sounds is of variable length. When the two components of the sound correspond to the sounds of the isometric systolic phase and the phase of expulsion (aortic opening), the interval is equivalent to the duration of the pressure rise (DPR). Measurement of the other sub-divisions of the systolic period and their comparison show that with increasing length of the preceding diastole the time of conversion is not modified, although the duration of the rise in pressure is shorter and the phase of expulsion is longer. The inspiratory increase in heart frequency with its short diastole follows a long DPR in relation to a short expulsion phase; the expiratory slowing in rate with its long diastole is accompanied by a short DPR and a long expulsion phase. The differences are statistically significant. Since it was not possible to effect measurements simultaneously of the first heart sound and intracardiac pressure because of technical difficulties, it is necessary to take account of the statistical correlation between the values for the doubling of the first heart sound with the records of the ECG, the phonocardiogram and the carotid pulse curve taken with a suitable neck cuff. Simultaneously, it is possible to register intracardiac pressures. These two different methods give significantly similar values. Arising from these facts, one can equally exclude other causes, such as the formation of a doubling sound originating in the left ventricle, the right or on both sides. No changes of pathological origin were detected. The values found are compared with those published in the literature and it appears that the DPR represents a subtle indicator of haemodynamic changes. Resume Sur les variations respiratoires des phases systoliques du coeur du chien On enregistre un dedoublement du premier bruit cardiaque chez le chien, a l'aide du phonocardiogramme. L'enregistrement du bruit cardiaque de ce dedoublement s'avere difficile au point de vue technique, mais est obtenu chez 5 chiens particulierement tranquilles, etroits de poitrine, a paroi thoracique mince. Avec une arythmie cardiaque respiratoire prononcee, l'intervalle du dedoublement est de longueur variable. Lorsque les deux composants du premier bruit correspondent aux bruits de la phase isometrique systolique et de la phase d'expulsion (bruit de l'ouverture aortique), l'intervalle est equivalent a la duree de l'augmentation de pression (DAP). La mesure des autres subdivisions de la periode systolique et leur comparaison montrent qu'avec un allongement de la diastole precedente, le temps de conversion n'est pas modifie, alors que la duree de l'augmentation de pression est plus courte et que la phase d'expulsion est plus longue. Lors de l'accroissement de frequence du coeur, pendant la phase inspiratoire, il s'ensuit une plus longue duree de l'augmentation de pression et respectivement une plus courte phase d'expulsion. Alors que pendant la phase expiratoire, avec sa diminution de la frequence cardiaque et ses plus longues diastoles, la phase d'expulsion est plus grande et la phase d'augmentation de pression est plus courte. Les differences sont statistiquement valables. Comme il n'a pas ete possible d'assurer les resultats des mesures par un enregistrement simultane du premier bruit cardiaque et des pressions intracardiaques, en raison des difficultes techniques, on s'est attache avant tout a la concordance des valeurs mesurees du dedoublement du premier bruit cardiaque, avec celles des traces de l'electrocardiogramme, du phonocardiogramme et du pouls carotidien, enregistre a l'aide d'un manchon adapte autour du cou. Pour cette mesure on peut, tout simplement, enregistrer la pression intracardiale. Entre ces deux methodes, on trouve egalement des valeurs comparables significatives. A partir de ces faits, on peut egalement exclure, d'autres causes, par exemple la formation d'un dedoublement du bruit d'origine ventriculaire gauche, ou bien, droite ou bilaterale. On ne trouve pas des modifications d'origine pathologique. De plus, nous avons compare nos valeurs avec celles de la litterature. Il s'avere que la DAP represente un indicateur fidele des modifications hemodynamiques. Resumen Las oscilaciones respiratorias de las fases sistolicas en el corazon de perro Con ayuda del fonocardiograma se represento una escision del primer tono cardiaco en el perro. El registro grafico del tono cardiaco de esta escision es dificil desde el punto de vista tecnico, pero se logro en 5 perros muy tranquilos, estrechos de pecho y con pared toracica delgada. En la arritmia cardiaca respiratoria manifiesta, el intervalo de escision tenia longitudes desiguales. Cuando ambas partes del tono corresponden al tono de tension y al tono expulsivo (tono de apertura aortica), el intervalo es igual al tiempo de aumento de la presion (TAP). La medicion de los subtiempos sistolicos restantes y la comparacion tiene por resultado que con la longitud creciente del diastole precedente no se halla alterado el tiempo de transformacion (TT), mientras que el TAP es mas breve y el tiempo de expulsion (S) mas largo. Al acrecentamiento inspiratorio de la frecuencia cardiaca con sus diastoles breves le sigue un TAP largo o un S breve, alretardoexpiratorio de la frecuencia con sus diastoles largos un TAP breve o un S largo. Las diferencias se hallan aseguradas estadisticamente. Puesto que no fue posible asegurar los resultados de medicion mediante la inscripcion simultanea del primer tono cardiaco y de la presion intracardiaca por dificultades metodologicas, se aseguro estadisticamente, en primer lugar, la concordancia de los valores de medicion de la division de tono del primer tono cardiaco con los del ECG, FCG y curva del pulso carotideo, tornado con un manguito cervical. Junto con esta medicion se pueden registrar simultaneamente las presiones intracardiacas. Tambien entre estas dos tecnicas se obtuvieron valores iguales significativos. Aparte de esta prueba, se excluyeron otras causas, taies como la formacion ventricular izquierda o derecha e incluso bilateral de duplicaciones del tono. No se registraron alteraciones patologicas. Para ello se compararon los valores con los mencionados en la bibliografia. Segun esto, parece ser que el TAP es un indicador primoroso para las alteraciones hemodinamicas.

Key Clinical Message Examination of apical impulse is an important component of nonauscultatory cardiac examination. Seesaw‐like movements of the chest wall during the systolic phase suggest severe tricuspid regurgitation.

The aim of this paper is to emphasise the role of the primary strain-line patterns in a human left ventricle (LV) within the complex system that is the heart. In particular, a protocol is proposed for the measurement of the principal strain lines (PSL) in the walls of the LV; this protocol is tested by means of a computational model which resembles a human LV. When the analysis is focused on the epicardial surface, PSL can be used to derive information on the directions of muscle fibres during the entire cardiac cycle, not only the systolic phase.

The aim of this study was to evaluate the regional (i.e. myocardial segments) variability as well as the overall image quality of cardiac T1 and T2 maps obtained in diastole and in systole. In 22 healthy subjects (group-1), diastolic T1 and T2 maps were obtained at 1.5T in short-axis view at basal, mid-ventricular and apical level, as well as in 4-chamber (4ch) and in 2-chamber (2ch) views. In another group of 25 patients (group-2), the maps were obtained in both diastole and systole. In the group-1, 15.4 % of myocardial segments in T1 maps and 0.8 % of myocardial segments in T2 maps, mainly located at apical level, showed relevant artifacts and/or partial-volume effect and had to be discarded. We found no significant difference in T1 values among basal, mid-ventricular and apical segments. T2 values at apical level were significantly higher than at basal and mid-ventricular level (short-axis, p < 0.0001; 4ch, p < 0.009; 2ch, p = 0.0002 at ANOVA tests). In the group-2, 21.1 %/5.3 % and 4.0 %/0.8 % of segments showed relevant artifacts in diastolic/systolic T1 and T2 maps, respectively. Apical T2 values were significantly lower in systole than in diastole. In systole, there were no significant differences in T1/T2 among basal, mid-ventricular and apical segments. The overall quality of T1 and T2 maps drops in apical segments. This could be problematic when evaluating focal myocardial changes. The acquisition in systole increases the number of evaluable segments.

We present recent investigations on the state of strain in human left ventricle based on the synergy between continuum mechanics and echocardiographic imaging. When data from three-dimensional Speckle Tracking Echocardiography are available, special strain directions can be detected on the epicardial and endocardial surfaces, which are well-known in continuum mechanics as principal strain lines (PSLs), further classified into primary and secondary strain lines. An appropriate investigation on PSLs can help to identify lines where strains are largest as primary and smallest as secondary. As PSLs change when cardiac diseases appear, the challenge is that the analysis may allow for the identification of new indicators of cardiac function.

In the present case, development of the string sign in an internal thoracic arterial graft was observed using transthoracic Doppler echocardiography. Following surgery, the diameter of the internal thoracic graft decreased; however, the diameter of the left anterior descending coronary artery did not change from 1.9 mm. Further, the flow velocity in the internal thoracic artery during the systolic phase became greater than that in the early phase and then decreased on postoperative day 19, and it was not detected on postoperative day 31. Coronary arteriography performed on postoperative day 31 revealed a severely stringed internal thoracic artery.

The effect of collagen fibers on the mechanics and hemodynamics of a trileaflet aortic valve contained in a rigid aortic root is investigated in a numerical analysis of the systolic phase. Collagen fibers are known to reduce stresses in the leaflets during diastole, but their role during systole has not been investigated in detail yet. It is demonstrated that also during systole these fibers substantially reduce stresses in the leaflets and provide smoother opening and closing. Compared to isotropic leaflets, collagen reinforcement reduces the fluttering motion of the leaflets. Due to the exponential stress-strain behavior of collagen, the fibers have little influence on the initial phase of the valve opening, which occurs at low strains, and therefore have little impact on the transvalvular pressure drop.

Leonardo's studies of cardiovascular systems, in more than 50 surviving pages from two phases of his research (around 1508–1509 and 1513), are a clear demonstration of his observational genius and progressive deduction of cardiac mechanics and the vascular system. He carried out a detailed hemodynamic study of the aortic valve motion and the role of the Sinus of Valsalva in the closure dynamics of the aortic valve, and he accurately correlated the formation of vortices with the separation of a retarded (shear) layer from the lips of the leaflets. In-vivo verification of vortex formation in the Sinus of Valsalva during the systolic phase awaited the application of modern phase-averaged magnetic resonance imaging techniques. Did Leonardo actually build the glass model he twice mentioned, thus performing the first scientific flow visualization of impulsive vortex formation or other fluid mechanical phenomena? Evidence in support of this possibility can be found in both the unusually schematic style he employed for this suite of drawings and the recent flow imaging results obtained in our laboratory through laser-based imaging techniques.

The physiological assessment of a lesion is a key to quality of life and prognosis of a patient with moderate coronary stenosis. Blood flow in coronary arteries occurs primarily during diastole, it is evident especially in the LAD. The systolic phase lasts roughly 300 ms and its duration is almost

Presaturation of fat signals by frequency-selective radiofrequency (RF) pulses is often applied in MR angiography to improve the visualization of the blood vessels. Unfortunately, standard fat saturation methods might cause a considerable reduction of the blood signal in the measured slices. This effect is caused by an attenuation of blood magnetization in remote tissue regions with water protons showing a similar Larmor frequency as the fat protons in the recorded slice. The affected blood water protons subsequently flow into the recorded slice and provide low signal intensity. Suitable spatial-spectral selective methods for slice-selective fat saturation were developed to avoid this unwanted effect. A spatial-spectral fat saturation technique was compared with a corresponding only spectrally selective approach. Both saturation techniques were included in a standard two-dimensional (2D) cine sequence and applied in angiographic examinations of the thighs. The results indicate that spatial-spectral saturation (acting slice selectively) leads to a clearly higher blood signal intensity in fat-suppressed MR angiography compared with standard techniques, especially in measurements performed during the systolic phase of the cardiac cycle.

Despite half a century of use, mechanical heart valves still require further research to reduce the non-physiologic nature of the flow field, which is the source of potential medical complications, of which the most serious complication is thrombus formation [1]. In the systolic phase of the flow, excessive fluid stresses are generated by the non-physiologic flow patterns [2, 3]. In the closed valve position, a large pressure gradient is imposed across the device which leads to the generation of strong and damaging small-scale leakage flows that entrain platelets such that they are exposed to elevated stresses for excessive time durations [4–6].

End-systolic pressure-volume relation (ESPVR) in the left ventricle is used to study the problem of heart failure with normal or preserved ejection fraction (HFpEF). This problem has recently been the object of several studies; most of these studies have concentrated on the variation of the dimensions of the left ventricle during the systolic phase. In this communication, we introduce mathematical relations that show the importance of the forces acting on the myocardium and the energy involved in the systolic contraction on the calculation of the ejection fraction (EF). Both can be derived in a simple way from the study of the pressure-volume relation (PVR) and the areas under the ESPVR. Alternative ways to assess the performance of the left ventricle are suggested.

This paper deals with the automated segmentation of left ventricle in cardiac MRI using level set and enhanced filtering technique. The main focus is on the graphical analysis techniques such as Bland & Altman plot and regression analysis in order to verify the validity of the system. The area of end diastolic and end systolic phase of the base to apex levels has been found using the above algorithm and compared with the manually segmented images.

MRI appears to be particularly attractive for the study of the Sinuses of Valsalva (SV), however there is no global consensus on their suitable measurements. In this paper, we propose a new method, based on the mathematical morphology and combining a numerical geodesic reconstruction with an area estimation, to automatically evaluate the SV from a cine-MRI in a cross-sectional orientation. It consists in the extraction of the shape of the SV, the detection of relevant points (commissures, cusps and the centre of the SV), the measurement of relevant distances and in a classification of the valve as bicuspid or tricuspid by a metric evaluation of the SV. Our method was tested on 23 patient examinations and radii calculations were compared with a manual measurement. The classification of the valve as tricuspid or bicuspid was correct for all the cases. Moreover, there are an excellent correlation and an excellent concordance between manual and automatic measurements for images at diastolic phase (r= 0.97; y = x - 0.02; p=NS; mean of differences = -0.1 mm; standard deviation of differences = 2.3 mm) and at systolic phase (r= 0.96; y = 0.97 x + 0.80; p=NS ; mean of differences = -0.1 mm; standard deviation of differences = 2.4 mm). The cross-sectional orientation of the image acquisition plane conjugated with our automatic method provides a reliable morphometric evaluation of the SV, based on the automatic location of the centre of the SV, the commissure and the cusp positions. Measurements of distances between relevant points allow a precise evaluation of the SV.

An experimental apparatus to model the systolic phase of a heartbeat has been developed to investigate the controversy surrounding the cause of high intraventricular pressures for HCM patients. The model, which is two-dimensional, has approximately seven times the volume of an average human heart and operates at Reynolds numbers which are similar to those measured in the left ventricle/aortic arch. Preliminary tests of the model show pressure time relationships similar to those found in vivo.

Objective To observe the therapeutic effect of acupuncture plus Ligustrazine on vertebrobasilar insufficiency (VBI) by transcranial Doppler (TCD) sonography. Methods 86 VBI patients including 56 cases of low flow rate velocity type (LFVT) and 30 cases of high flow velocity type (HFVT) were randomly divided into Ligustrazine group (26 LFRT and 14 HFVT) and acupuncture plus Ligustrazine group (30 LFVT and 16 HFVT). The blood flow velocity (BFV) of vertebral artery (VA) and basilar artery (BA) in systole before and after treatment was measured with TCD and therapeutic effects were evaluated after 10 days' treatment in the two groups. Results In the acupuncture plus Ligustrazine group, the total effective rate was 93.3% and 88.5% in cases of LFVT and HFVT respectively, and BFV of VA and BA increased in LFVT patients while that in HFVT patients decreased significantly ( P P Conclusion Owing to its dual regulation on blood flow of VA and BA, the therapeutic effect of acupuncture plus Ligustrazine was better than that of simple Ligustrazine.

The changes of coronary blood circulation occur mainly due to changes in the rate of the resistance of coronary arteries. EECP is one of the new effective facilities in treatment of coronary arteries diseases and cardiac failure through increasing the flow in coronary arteries in diastole and lowering the load in systolic phase.

Background The effects of ischemia are first realized in the subendocardium and progress transmurally. Hence, detection of the transmural extent of myocardial perfusion (MP) defects has important diagnostic/prognostic implications. Systolic MP imaging using ECG-gated methods has been shown to provide improved visualization of subendocardial defects [1]. We developed an innovative non-ECGgated perfusion CMR technique capable of imaging all slices at the same systolic phase, and hypothesized that it improves visualization of the transmural extent of MP defects compared to the conventional method in CMR studies of CAD patients.

This study is to quantitatively evaluate abnormal movement of mitral apparatus (MA) in patient with congenital mitral valve regurgitation using self-designed three dimensional motion analyses software and enable doctors to intuitionistic and "en-face" visualize the mitral valve's movement by using pseudocolor coding of the moving velocity of mitral valve leaflet. Initial evaluation of the software was conducted in 20 children with congenital mitral valve regurgitation (MR) including 10 children with mild MR and 10 children with moderate to severe MR. Results showed that, the moving velocity of the rough zone of mitral valve during systolic phase in children with moderate to severe MR is much high than that in control group. It's indicated that three dimensional motion analysis of mitral valve could emerge to be a new potential useful parameter for evaluation the truly mechanism of MR

We propose a new approach for tracking the cardiac motion by using simultaneously short-axis and long-axis MR images in non-rigid registration. The fusion of two image orientations allows to track more precisely the basal and apical movement of the ventricles. In addition, the motion of the atria is tracked. Correlation coefficients were 0:94 at the systolic phase and 0:97 at the diastolic phase as the volumes of manually and automatically detected chambers were compared. The results were obtained using 7 subjects.

Closed loop stimulation (CLS) is the algorithm implemented in the INOS2+ (Biotronik, Germany) pacemaker to perform rate modulation in dual or single chamber pacing. CLS is driven by a “virtual sensor” that detects the variations in intracardiac impedance during the systolic phase of right ventricular contraction [1,2].

says that the annular dilatation process is predominantly seen in the posterior annulus and it also involves the anterior part of the annulus, although to a lesser extent than the posterior annulus. There is no structure that prevents the annulus from dilatation in the sutureless transapical replacement of the valved stent in the mitral position. Therefore, left ventricular pressure in the systolic phase of cardiac cycle and even dynamic movement of the left heart may result in the separation of the annulus from the valved stent, especially in the posterior part of the annulus in the long-term follow-up. In conclusion, it is an admirable study. We readers thank the authors for sharing their experience and knowledge of a new surgical approach to minimally invasive mitral valve replacement. The explanation of previously described points may necessitate further investigation to overcome possible fixation problems.

CSF flow dynamics has been known to have a key role the pathogenesis of syringomyelia. Our purpose was to evaluate the CSF flow pattern in syringomyelia with spatial modulation of magnetization (SPAMM) that can depict directional flow, and to determine the relationship between flow dynamics and clinical outcome after decompress surgery. We performed pre- and post-operative MRI in 9 patients with syringomyelia with SPAMM technique. They showed caudal shift of tagging bands in the syrinx cavity in systolic phase while stagnation of CSF flow was seen in diastolic phase. The degree of band shift in syrinx was well correlated with the degree of shrinkage in size of syrinx after operation. Evaluation of syringomyelia by SPAMM technique can predict postsurgical outcome after decompress surgery.

Myocardial contractility is a cyclic phenomenon regulated by individual autonomous mechanisms. In each cycle, two defined phases, may be distinguished. 1. The systolic phase corresponding to the setting in tension of the myocardial fibers and their secondary stretch. This phase has as consequence the expulsion of a part of the blood volume contained in the ventricular cavities, denominated stroke volume (SV). 2. The diastolic phase, during which a progressive relaxation of the myocardial fibers takes place, allowing the filling, also progressive, of the ventricular cavities.