Ventricular Diastole Research Articles

Abstract 19158: MRI Based Non-Invasive Measures Correlates With Invasive Measurements of Left Atrial Diastolic Function in Atrial Fibrillation Patients

Background: Atrial fibrillation (AF) is associated with diminished cardiac functions. This study describes a novel methodology for non-invasive measurement of left atrial (LA) function in patients with AF. Methods: A total of 55 patients (81% male, 55% paroxysmal, 60.4±10.2 years) underwent cardiac MRI prior to AF ablation. Invasive LA pressure was measured during sinus rhythm following trans-septal puncture for AF ablation. LA pressure and volume (MRI derived) loops were prepared for all patients. LA diastolic function was defined as the ratio of the change in LA pressure to the change in LA volume during passive LA filling. Additionally, the ratio of pulmonary vein flow velocities during ventricular systole and diastole were obtained using phase contrast MRI (Figure top panel, S/D ratio). Patients with ventricular diastolic dysfunction (as seen by E/A ratio) were excluded. LA systolic functions were calculated from the active emptying fraction during atrial contraction. Diastolic dysfunction scores greater than the 90th %tile (>1.6mmHg/ml) were considered to signify severe diastolic dysfunction. Results: The mean diastolic dysfunction score was 0.76±0.7 mmHg/ml. The score was higher in patients with persistent versus paroxysmal AF (1.0±0.9 vs. 0.60±0.5,p=0.02). The mean S/D ratio was 1.04±0.6; and was lower in patients with persistent versus paroxysmal AF (0.9±0.5 vs. 1.2±0.7, p=0.04). There was a negative linear association between diastolic dysfunction scores and S/D ratio measures (Figure bottom panel, p <0.001). In a multivariate analysis adjusting for age, LA systolic function and CHADS2 score, the severe diastolic dysfunction was independently associated with lower S/D ratio (p-0.03). Conclusion: The non-invasive MRI derived ratio of pulmonary vein flow velocities during systole and diastole are associated with the MRI/invasive derived diastolic dysfunction score, and appear to be a fair surrogate of LA diastolic function.

Mid-diastolic mitral flow vectors in complete atrioventricular block.

An 81-year-old man who was treated for prostate cancer was referred to our department because of bradycardia. He had a 1-month history of shortness of breath. A 12-lead electrocardiogram (ECG) showed complete atrioventricular (AV) block. His blood pressure was 165/78 mmHg and pulse rate was 38 beats/ min. Results of blood sampling were normal. A transthoracic echocardiogram revealed normal left ventricular (LV) wall thickness (interventricular septal thickness, 8 mm; LV posterior wall thickness, 8 mm) and normal LV systolic function (LV end-diastolic dimension, 39 mm; LV end-systolic dimension, 22 mm; LV ejection fraction, 76 %). A color-coded 2-dimensional echocardiogram showed no significant valvular disease. During mid-diastole, mitral forward and regurgitant flows were intermittently observed (Fig. 1). Color-coded M-mode echocardiography also showed intermittent mitral forward and regurgitant flows (Fig. 2). Simultaneous ECG recording indicated a relationship between the timing of the P wave and the T wave and the direction of mid-diastolic flow. Middiastolic mitral inflow was observed when the P wave was on the T wave, while diastolic mitral regurgitation (MR) was observed when the P wave emerged after the T wave (Figs. 1, 2). After treatment of complete AV block by pacemaker implantation, neither type of mitral flow was observed. Mid-diastolic mitral forward flow can be observed in some patients with advanced LV diastolic dysfunction. In these cases, mid-diastolic flow may be a result of interruption of early diastolic mitral inflow (E wave) by transient elevation of LV pressure [1, 2]. In the present case of complete AV block, mid-diastolic forward flow was observed when the P wave overlapped with the T wave. It is probable that mid-diastolic flow in this case might be a result of E wave interruption by transient fall of left atrial (LA) pressure by atrial relaxation. Diastolic MR is observed when the AV pressure gradient is reversed because the mitral valve does not close firmly during diastole. In complete AV block, diastolic MR can be observed when atrial relaxation occurs during ventricular diastole [3]. Moreover, decreased LV compliance [4] and early diastolic LV hyperinflation [5] may also play a part. In this patient with complete AV block, the timing of atrial relaxation might have played a decisive role in the mid-diastolic mitral inflow velocity and diastolic MR.

In-vivo mitral annuloplasty ring transducer: Implications for implantation and annular downsizing

Mitral annuloplasty has been a keystone to the success of mitral valve repair in functional mitral regurgitation. Understanding the complex interplay between annular-ring stresses and left ventricular function has significant implications for patient-ring selection, repair failure, and patient safety. A step towards assessing these challenges is developing a transducer that can be implanted in the exact method as commercially available rings and can quantify multidirectional ring loading. An annuloplasty ring transducer was developed to measure stresses at eight locations on both the in-plane and out-of-plane surfaces of an annuloplasty ring's titanium core. The transducer was implanted in an ovine subject using 10 sutures at near symmetric locations. At implantation, the ring was observed to undersize the mitral annulus. The flaccid annulus exerted both compressive (−) and tensile stresses (+) on the ring ranging from −3.17 to 5.34MPa. At baseline hemodynamics, stresses cyclically changed and peaked near mid-systole. Mean changes in cyclic stress from ventricular diastole to mid-systole ranged from −0.61 to 0.46MPa (in-plane direction) and from −0.49 to 1.13MPa (out-of-plane direction). Results demonstrate the variability in ring stresses that can be introduced during implantation and the cyclic contraction of the mitral annulus. Ring stresses at implantation were approximately 4 magnitudes larger than the cyclic changes in stress throughout the cardiac cycle. These methods will be extended to ring transducers of differing size and geometry. Upon additional investigation, these data will contribute to improved knowledge of annulus-ring stresses, LV function, and the safer development of mitral repair techniques.

GW24-e3131 Evaluation of left ventricular diastolic synchronism in patients with hypertrophic cardiomyopathy by two dimensional speckle tracking imaging

ObjectivesTo evaluate diastole synchrony of the different segments of left ventricular in patients with hypertrophic cardiomyopathy by two dimensional speckle tracking imaging.MethodsForty-seven patients with HCM and thirty-three healthy volunteers were...

Comparison of left atrial function in healthy individuals versus patients with non-ST-segment elevation myocardial infarction using two-dimensional speckle tracking echocardiography : cardiovascular topics

Left atrial (LA) function has been associated with adverse outcomes in patients after acute myocardial infarction. The purpose of the current study was to evaluate LA function in patients with non-ST-segment elevation myocardial infarction (NSTEMI) by two-dimensional speckle tracking echocardiography (2D STE). Fifty-one patients with NSTEMI and 40 age-matched normal control individuals were enrolled in this study. Conventional echocardiographic parameters and global longitudinal strain rate (GLSR) were measured at left ventricular (LV) and LA segments. Compared with healthy subjects, patients with NSTEMI had significantly increased LA volumes but significantly decreased LA emptying fraction and GLSR. LA-GLSR had significant correlations with the 2D Doppler echocardiographic parameters of LA function. In particular, global LA peak negative strain rate during early ventricular diastole (LA-GLSRe) was significantly correlated with both LA 2D Doppler echocardiographic parameters and LV contractile function. This could be suggested as a better indicator to evaluate LA function as a preferred parameter of STE.

ASSA13-03-18 Precondition with CyclinA2 Promote Cardiac Regeneration After Myocardium Infarction Via the Recruitment of C-Kit+ Cells

Objective Downregulation of CyclinA2 till disappearance in mammalian heart after birth is associated with the withdrawal of cardiomyocytes from cell cycle. We hypothesis that exogenous CyclinA2 transferred into infracted myocardium might induce cardiac regeneration and reactivate cardiomyocytes cell cycle. Methods Adeno-associated virus type 9 -CyclinA2-CMV recombinant was constructed and 2 × 10 11 vg constructs in 200ul of saline were deliveried into mice myocardium through tail vein one week before MI created (n = 20). The control group (n = 20) were injected with saline at a same volume and time. Post-MI observation were respectively 1 week and 3weeks. Echocardiography was performed to measure Left Ventricular End Diastole Diameter (LVEDD), Left Ventricular End Systolic Diameter (LVESD) and Ejection Fraction (EF). Western blot and immunohistochemical analysis were used to detect the expression and location of CyclinA2. DNA synthesis and mitosis were respectively analysed by PCNA and phosphohistone-H3. C-kit and connexin 43 were also measured. Masson’s trichrome stain was used to measue collagen volume in two groups. Results CyclinA2 located in cytoplasm but not nuclear after transferred. Western blot showed that expression of CyclinA2 in two groups has a significant statistical difference (p group than control (0.75 + 0.03 VS 0.43 + 0.02, p = 0.036). However mitosis specific protein H3P had no statistical difference in two groups (p > 0.05). C-kit expression showed an increase in CyclinA2 treated group but no change in control (p Conclusions Expression of Cyclin A2 via gene transfer induced cardiomyocyte DNA synthesis but no mitosis. Cyclin A2 might promote cardiac regeneration via the recruitment of c-kit+ cells which had been known as a cardiac stem cell marker. Continuous expression of CyclinA2 improved cardiac function after MI.

Quantification of left and right atrial kinetic energy using four-dimensional intracardiac magnetic resonance imaging flow measurements

Kinetic energy (KE) of atrial blood has been postulated as a possible contributor to ventricular filling. Therefore, we aimed to quantify the left (LA) and right (RA) atrial blood KE using cardiac magnetic resonance (CMR). Fifteen healthy volunteers underwent CMR at 3 T, including a four-dimensional phase-contrast flow sequence. Mean LA KE was lower than RA KE (1.1 ± 0.1 vs. 1.7 ± 0.1 mJ, P < 0.01). Three KE peaks were seen in both atria: one in ventricular systole, one during early ventricular diastole, and one during atrial contraction. The systolic LA peak was significantly smaller than the RA peak (P < 0.001), and the early diastolic LA peak was larger than the RA peak (P < 0.05). Rotational flow contained 46 ± 7% of total KE and conserved energy better than nonrotational flow did. The KE increase in early diastole was higher in the LA (P < 0.001). Systolic KE correlated with the combination of atrial volume and systolic velocity of the atrioventricular plane displacement (r(2) = 0.57 for LA and r(2) = 0.64 for RA). Early diastolic KE of the LA correlated with left ventricle (LV) mass (r(2) = 0.28), however, no such correlation was found in the right heart. This suggests that LA KE increases during early ventricular diastole due to LV elastic recoil, indicating that LV filling is dependent on diastolic suction. Right ventricle (RV) relaxation does not seem to contribute to atrial KE. Instead, RA KE generated during ventricular systole may be conserved in a hydraulic "flywheel" and transferred to the RV through helical flow, which may contribute to RV filling.

Effects of vagal maneuvers on heart rate and Doppler variables of left ventricular filling in healthy cats

BackgroundEvaluation of left ventricular (LV) diastole is clinically important in cats with heart disease. Diastolic dysfunction is a main characteristic of feline cardiomyopathy and is associated with clinical signs and poor outcome. Numerous echocardiographic indices characterizing LV diastole exist, of which Doppler variables of transmitral flow and mitral annular motion are used most often. However, rapid heart rate (HR), a common finding in cats examined in the veterinary hospital environment, may cause summation of flow waves limiting interpretation of diastolic function. ObjectiveTo evaluate the effects of vagal maneuvers (gentle eyeball pressure and nasal planum massage) on HR and Doppler variables of LV diastolic filling. AnimalsTwenty-four healthy client-owned cats with summated transmitral flow waves at baseline. MethodsProspective observational study. Transthoracic echocardiography was performed and Doppler transmitral and mitral annular tissue Doppler velocities recorded both before and during vagal maneuvers. Data were compared using a paired t-test. ResultsApplication of vagal maneuvers temporarily decreased HR in all cats (mean reduction ± SD; 42 ± 22 bpm). The duration of HR reduction (<5 s, 5–10 s, and >10–15 s) was evenly distributed among groups (8 cats in each). Summated Doppler transmitral flow and mitral annular tissue velocity waves were separated during vagal maneuvers in 71% and 72% of cats, respectively. No adverse effects were observed. ConclusionsVagal maneuvers may be utilized as a simple non-pharmacologic tool in the Doppler evaluation of LV diastolic function in healthy cats.

Atrial aspiration from pulmonary and caval veins is caused by ventricular contraction and secures 70% of the total stroke volume independent of resting heart rate and heart size

Whereas ventricular filling has been extensively studied and debated, atrial filling is less well characterized. Therefore, the aim of this study was to quantify atrial filling secured during ventricular diastole and systole, and to investigate whether atrial filling depends on heart rate (HR) and total heart volume (THV). Thirty-two athletes (16 women) and 32 normal subjects (16 women) underwent cardiac magnetic resonance imaging. Cardiac volumes and atrioventricular plane displacement (AVPD) were determined. Longitudinal and radial contribution to stroke volume was calculated using planimetry and used to determine diastolic and systolic atrial filling. Atrial filling during ventricular diastole was 29±10% of the total stroke volume, and during ventricular systole atrial filling was 68±8% of the total stroke volume. There were no differences between groups of different HR (P=0·70 and P=0·41 for diastolic and systolic filling, respectively) or THV (P=0·44 and P=0·46 for diastolic and systolic filling, respectively). Systolic atrial filling was strongly correlated to longitudinal ventricular pumping (R=0·76, P<0·001). This study demonstrated that in healthy humans at rest, approximately 30% of the total stroke volume enters the atria during ventricular diastole and approximately 70% during systole, independent of heart rate (HR) or heart size. The atria are filled through suction driven by ventricular longitudinal contraction which aspirates blood from the pulmonary and caval veins. As 70% of the atrial filling occurs during ventricular emptying, the heart volume remains relatively constant over the cardiac cycle, which minimizes pulling on surrounding tissues and therefore optimizes energy expenditure.

Intra-left Atrial Flow Changes During the Start of Atrial Fibrillation

In the present study, our aim was to visualise the changes in the left atrial flow during atrial fibrillation (AF)using numerical simulations and an animal experiment. A geometric model of the left atrium (LA) was constructed based on MR images obtained into a computational model created using tetrahedral mesh. A flow simulation was performed using FLUENT. To simulate AF, we added low-amplitude and high-frequency contractions to the sinus rhythm (SR) mode, and subtractedactive contractions while the mitral valve was opening. In a goat model, the intra-left atrial flow was directly visualised with microbubble contrast agents using echocardiography under general anesthesia. The LA was electrically fibrillated during 9 V direct current stimulation of the left atrial wall. SR was recovered soon after the stimulation was terminated. The results of the computer simulation showed that, a small rotational flow present during ventricular diastole disappeared in the AF model. A large number of eddies were evident along the superior left pulmonary vein. During ventricular systole, although a vortex was formed, the density of the streamlines was lower than that observed in the SR model. In the animal experiment, the flow was obscured by local eddies when AF occurred. Some microbubbles remained at the junction of the left atrial body and pulmonary vein. Compared with the SR, the atrial vortices became obscured by an increased number of local eddies along the superior left pulmonary vein when AF was present, after which the intra-left atrial flow became congested.

Exercise-induced torsional dyssynchrony relates to impaired functional capacity in patients with heart failure and normal ejection fraction

BackgroundLeft ventricular (LV) systole and diastole are intimately dependent on myocardial torsion, which involves coupling between myocardial rotation (twisting in systole and untwisting in diastole) and longitudinal motion. Heart failure...

Altered Diastolic Left Atrial and Ventricular Performance in Asymptomatic Patients After Repair of Tetralogy of Fallot

We evaluated the interaction of left atrial and ventricular diastolic performance in asymptomatic children and young adults after ToF-repair (n=25). Those young people, as well as 25 age matched healthy children and young adults were examined using non-invasive conventional echocardiography. Regional systolic and diastolic myocardial strain and strain rate in left atrium and ventricle were analysed using 2D-speckle-tracking (Vivid VII, EchoPacGE). We collected planimetric data about the left atrial and ventricular performance during systole (volumetric LVEF, LV-Tei-Index, MV-E/E'-Ratio) and diastole (LAEF, LVEDV, left atrial volume). Registration of right pulmonary-venous inflow-patterns during ventricular systole, diastole and active atrial contraction was used to support assessment of left atrial function. To verify the timing of left atrial contraction and possible electromechanical delay we measured several ECG-related time-intervals. Statistical analysis included Mann-Whitney-U-Test, Bonferroni-Holm-Test and two-tailed Spearman-Correlation. Systolic pulmonary-venous inflow in ToF-patients was not different compared to the controls. Early diastolic pulmonary-venous inflow was significantly higher in ToF-patients as well as the LV-Tei-Index. The MV-E/E'-ratio, which is closely related to LVEDP, was significantly higher in ToF-patients and correlated with the early diastolic pulmonary venous inflow parameters such as the maximum diastolic bloodflow speed. Diastolic left atrial and ventricular strain and strain rate in ToF-patients did not differ from those in the controls. During late diastole there was a significantly premature timing of maximum myocardial strain rate of the interatrial septum and time-ratio of P-wave origin to maximum reverse pulmonary-venous blood flow and the duration of one heart action. Furthermore the maximum late diastolic reverse pulmonary-venous blood flow was significantly higher in ToF-patients. Those observations indicate a premature active left atrial contraction in late diastole in ToF-patients compared to the controls. In asymptomatic young patients after ToF-repair earlier and increased left atrial contraction was found, which may indicate adaptive compensatory mechanisms to overcome latent and asymptomatic altered systolic and diastolic left ventricular performance. Extensive assessment of left atrial parameters including the pulmonary veins should be considered in terms of an entire evaluation of left heart function in patients after ToF-repair.

Abstract 9117: Changes in Left Ventricular Diastolic and Left Atrial Function One Month After Transcatheter and Surgical Aortic Valve Replacement in Severe Aortic Valve Stenosis

Background: In the randomized Placement of Aortic Transcatheter Valves (PARTNER) trial, the NYHA functional class was improved at 1 year in both the transcatheter aortic valve replacement (TAVR) and the surgical bioprosthetic aortic valve replacement (SAVR). However, more patients in TAVR than in SAVR had a reduction in symptoms at 30 days. As part of a single center PARTNER trial experience, we compared left ventricular (LV) and left atrial (LA) function in patients after TAVR with those with SAVR for the treatment of severe aortic valve stenosis at one month follow-up. Methods and Results: A total of 83 severe aortic valve stenosis patients with preserved LV systolic function (EF &gt; 40%) and without moderate or severe valvular regurgitation were included in the study: 52 patients underwent TAVR and 31 patients underwent SAVR. Echocardiographic parameters were similar between the two groups. In each group, LVEF and peak early diastolic mitral annular velocity (e') increased significantly at one month follow-up. The ratio of peak S-wave to D-wave from pulmonary vain flow (PVS/PVD) was higher in the TAVR group as compared with the baseline, while there is no significant difference in SAVR group. LV end-diastolic dimension (LVEDD), left atrial area (LAA), the ratio of early transmitral flow velocity (E) to e' (E/e') and LV mass index significantly decreased as compared with baseline in each group (Table 1). There were no significant differences between the two groups in LVEDD, EF, LAA, PVS/PVD, e', E/e' and LV mass index one month after the procedure. At one month follow-up, however, the changes (post minus pre) of LAA, PVS/PVD, e' and E/e' were significantly larger in the TAVR group than the SAVR group (Table2). Conclusion: In patients with severe aortic stenosis, both TAVR and SAVR improved LV systolic and diastolic function and LA function one month after intervention. In particular, the improvement after TAVR appeared to be greater than after SAVR.

Highlights from the Literature

Highlights from the Literature

Value of Dynamic Substrate Mapping to Identify the Critical Diastolic Pathway in Postoperative Ventricular Reentrant Tachycardias After Surgical Repair of Tetralogy of Fallot

Characterization of the Critical Isthmus in VT in TOF. The complexity of postoperative ventricular reentrant tachycardias may limit success of catheter ablation. The objective of this analysis was to compare the usefulness of dynamic substrate mapping (DSM) versus color-coded isopotential mapping of the noncontact mapping system for the identification of the critical diastolic pathway of postoperative ventricular reentrant tachycardias (VT) after surgical repair of tetralogy of Fallot (TOF). Postoperative VT had been studied applying isopotential maps with the noncontact mapping system EnSite in 7 patients, and radiofrequency current lesion lines had been applied across the shortest isthmus to target during sinus rhythm. Data of the noncontact mapping system were reanalyzed applying the DSM algorithm. For DSM, a 2-Hz filter and color settings between 0 mV and 50% of peak negative voltage (PNV) with autofocus turned off were used. DSM was initially applied over the QRS complex duration during sinus rhythm. Abnormal myocardium was defined as <35-40% of PNV. DSM was subsequently applied to ventricular diastole during the final 33% of VT cycle length. Areas with >70% of PNV within this time frame were to identify the critical diastolic pathway. Applying DSM, the critical diastolic pathway of the VT was identified in all 7 patients that corresponded to the regions targeted for ablation. By focusing the time reference to electrical diastole, when the VT wavefront is moving through the low-voltage area, the region of greatest relative voltage could be highlighted, which corresponded to the diastolic pathway. (J Cardiovasc Electrophysiol, Vol. 23, pp. 930-937, September 2012).

In-vivo transducer to measure dynamic mitral annular forces

Limited knowledge exists regarding the forces which act on devices implanted to the heart's mitral valve. Developing a transducer to measure the peak force magnitudes, time rates of change, and relationship with left ventricular pressure will aid in device development. A novel force transducer was developed and implanted in the mitral valve annulus of an ovine subject. In the post-cardioplegic heart, septal-lateral and transverse forces were continuously measured for cardiac cycles reaching a peak left ventricular pressure of 90mmHg. Each force was seen to increase from ventricular diastole and found to peak at mid-systole. The mean change in septal-lateral and transverse forces throughout the cardiac cycle was 4.4±0.2N and 1.9±0.1N respectively. During isovolumetric contraction, the septal-lateral and transverse forces were found to increase at peak rate of 143±8N/s and 34±9N/s, respectively. Combined, this study provides the first quantitative assessment of septal-lateral and transverse forces within the contractile mitral annulus. The developed transducer was successful in measuring these forces whose methods may be extended to future studies. Upon additional investigation, these data may contribute to the safer development and evaluation of devices aimed to repair or replace mitral valve function.

Ductus venosus Doppler velocimetry in normal pregnancies from 11 to 13 + 6 weeks' gestation—A Taiwanese study

BackgroundTo investigate flow in the ductus venosus at 11–13 + 6 weeks of gestation in women with normal pregnancies in the Taiwanese population. MethodsTwo hundred and fifty-two normal singleton pregnancies with gestational ages ranging from 11 to 13 + 6 weeks were examined in this study. The pulsatility index for veins (PIV), resistance index (RI), peak velocity during ventricular systole (S-wave), and peak velocity during ventricular diastole (D-wave) were recorded from the ductus venosus. ResultsWe analyzed 252 participants who all fulfilled the inclusion and exclusion criteria of our study. The mean maternal age was 31 (range 19–45 years), with a corresponding gestational age of 12 + 4 weeks (range 11–13 + 6). No significant change was found in the vascular indices as gestational age increased for the S-wave (S-wave = 1.4214 (GA) + 17.448, r = 0.09, P = 0.154), PIV (PIV = −0.0358 (GA) + 1.4143, r = −0.05, P = 0.378) and RI (RI = −0.035 (GA) + 1.1478, r = −0.064, P = 0.468). In contrast, the D-wave behaved differently from the other variables. There was a significant increase (r = 0.155, P = 0.013) in the D-wave with gestational age (D-wave = 1.4896 (GA) – 7.1547). ConclusionD-wave velocity in the ductus venosus increased with gestational age. S-wave peak velocity showed an increasing trend and PIV showed a decreasing trend with gestational age, but they did not reach statistical significance.

Problems With Excess Mitral Leaflet After Repair: Possible Issues During Repair and Preservation of the Posterior Leaflet

THE NORMAL NATIVE MITRAL VALVE exists in a dynamic balance involving all components of the apparatus to provide optimal coaptation during ventricular systole and minimal resistance to forward flow during ventricular diastole. The repaired myxomatous mitral valve has a similar balance, but with different annular and leaflet dimensions. Most commonly, repairs include resection and reduction of the posterior leaflet (PL) and a reduction annuloplasty, with or without repair of the anterior leaflet (AL). Green et al 1 Green G.R. Dagum P. Glasson J.R. et al. Restricted posterior leaflet motion after mitral ring annuloplasty. Ann Thorac Surg. 1999; 68: 2100-2106 Abstract Full Text Full Text PDF PubMed Scopus (109) Google Scholar described the postrepair PL as restricted, acting to buttress the coapting AL. Functionally, this repaired valve appears like a “unicuspid valve,” which relies heavily on a normally functioning AL. 1 Green G.R. Dagum P. Glasson J.R. et al. Restricted posterior leaflet motion after mitral ring annuloplasty. Ann Thorac Surg. 1999; 68: 2100-2106 Abstract Full Text Full Text PDF PubMed Scopus (109) Google Scholar , 2 Jebara V.A. Mihaileanu S. Acar C. et al. Left ventricular outflow tract obstruction after mitral valve repair Results of the sliding leaflet technique. Circulation. 1993; 88: 30-34 Google Scholar Successful Echocardiography-Guided Management of Refractory Postoperative Hypotension After Alfieri Repair of the Mitral ValveJournal of Cardiothoracic and Vascular AnesthesiaVol. 27Issue 3PreviewWe read with interest the article by Maslow et al1 titled “Problems With Excess Mitral Leaflet After Repair: Possible Issues During Repair and Preservation of the Posterior Leaflet.” We share our experience of successfully managing a case of refractory hypotension and deteriorating hemodynamics in a patient after Alfieri repair of the mitral valve for severe mitral regurgitation (MR). Full-Text PDF

Assessment of Left Atrial Mechanics in Patients with Atrial Fibrillation: Comparison between Two-Dimensional Speckle-Based Strain and Velocity Vector Imaging

Two-dimensional (2D) speckle tracking-derived left atrial (LA) strain (ε) facilitates comprehensive evaluation of LA contractile, reservoir, and conduit function; however, its dependence on the individual software used for assessment has not been evaluated. The aim of this study was to compare LA ε derived from two different speckle-tracking software technologies, Velocity Vector Imaging (VVI) and 2D speckle-tracking echocardiography (STE). VVI-derived and 2D STE-derived global longitudinal LA ε and ε rate (SR) were directly compared in127 patients (mean age, 62 ± 10 years) with atrial fibrillation. Peak negative, peak positive, and total ε(corresponding to LA contractile, conduit, and reservoir function) were measured during sinus rhythm. Late negative (LA contraction), peak positive (left ventricular systole), and early negative (left ventricular early diastole) SR were also measured. The measurement of LA ε and SR by both software was feasible in high proportions of patients (93% with VVI and 93% with 2D STE). The average analysis of ε(negative) was -7.24 ± 3.87% by VVI and -7.30 ± 3.37% by 2D STE (P= .84). The average analysis of ε(positive) was 14.52 ± 5.82% by VVI and 10.74 ± 4.51% by 2D STE (P < .01). The average analysis of ε(total) was 21.76 ± 7.39% by VVI and 18.04 ± 5.98% by 2D STE (P < .01). VVI-derived and 2D STE-derived ε(positive), ε(negative), and ε(total) had good correlations with one another (R= 0.79, R= 0.75, and R= 0.80), with low mean differences. Late negative, peak positive, and early negative SR were correlated less well (R= 0.78, R= 0.71, and R= 0.67). LA ε measurement using both VVI and 2D STE is feasible in a large proportion of patients in clinical practice. VVI and 2D STE provide comparable LA ε and SR measurements for LA contractile function.

The Effect of Mitral Annuloplasty Shape in Ischemic Mitral Regurgitation: A Finite Element Simulation

Undersized mitral annuloplasty (MA) is the preferred surgical treatment for chronic ischemic mitral regurgitation. However, the preferred shape of undersized MA is unclear. A previously described finite element model of the left ventricle with mitral valve based on magnetic resonance images of a sheep with chronic ischemic mitral regurgitation after posterolateral myocardial infarction was used. Saddle-shape (Edwards Physio II) and asymmetric (IMR ETlogix) MA rings were digitized and meshed. Virtual annuloplasty was performed using virtual sutures to attach the MA ring. Left ventricular diastole and systole were performed before and after virtual MA of each type. Both types of MA reduced the septolateral dimension of the mitral annulus and abolished mitral regurgitation. The asymmetric MA was associated with lower virtual suture force in the P2 region but higher force in P1 and P3 regions. Although both types of MA reduced fiber stress at the left ventricular base, fiber stress reduction after asymmetric MA was slightly greater. Neither type of MA affected fiber stress at the left ventricular equator or apex. Although both types of MA increased leaflet curvature and reduced leaflet stress, stress reduction with saddle-shape MA was slightly greater. Both MA types reduced stress on the mitral chordae. The effects of saddle-shape and asymmetric MA rings are similar. Finite element simulations are a powerful tool that may reduce the need for animal and clinical trials.