Mitral valve early systolic billowing induces following annular expansion and leaflet augmentation in Barlow's disease: sequential analysis using 3D echocardiography.

AIMS: Although systolic expansion of the annulus has been recognized in Barlow's disease, the mechanisms of the unique pathological movement of the annulus and its relation to the leaflet augmentation have not yet been clarified. We aimed to investigate the detailed mechanisms of the characteristic mitral apparatus dynamics in Barlow's disease by frame-by-frame sequential geometric analysis using real-time 3D transoesophageal echocardiography. METHODS AND RESULTS: Fifty-three patients with Barlow's disease and severe mitral regurgitation without torn chordae, as well as 10 controls, were included. We evaluated geometric changes in the mitral complex using 3D transoesophageal echocardiography at five points during systole. To identify early systolic billowing of leaflets, the annulo-leaflet angle was measured. We also performed a more detailed analysis in four consecutive frames just before and after leaflet free-edge prolapse above the annulus plane. The median annulo-leaflet angle of both leaflets in early systole was >0° (above annulus plane) in patients with Barlow's disease, and billowing of the leaflet body was observed from early systole. The prolapse volume of both leaflets increased markedly from early to mid-systole [1.60 (0.85-2.80) to 4.00 (2.10-6.45) mL; analysis of variance (ANOVA), P < 0.001; post hoc, P < 0.05]. With frame-by-frame analysis, dynamic augmentation of the annulus and leaflets developed between frames just before and just after leaflet free-edge prolapse (ANOVA, P < 0.01; post hoc, P < 0.05). CONCLUSION: In Barlow's disease, early systolic billowing of the mitral leaflet induces systolic annulus expansion followed by leaflet augmentation and leaflet free-edge prolapse.

Sheath shape pattern during leadless pacemaker implantation.

PURPOSE: Options for shaping the delivery sheath of leadless pacemakers (LPs) based on the cardiac anatomy of patients are limited. We predicted the shape of the LP sheath during implantation using preoperative computed tomography (CT) and intraoperative fluoroscopy. METHODS: Forty-eight patients with implanted LPs due to symptomatic bradyarrhythmia were divided into two groups, α-loop and non-α-loop, based on the shape of the LP delivery sheath head at implantation. Angles between the inferior vena cava (IVC) and the interventricular septum (IVST), and the IVC and right ventricular apex (RVA) were measured by CT. The relationship between the final sheath shape and position of the IVC and the right or left side of the line drawn vertically from the deflection point of the sheath in the LAO view on fluoroscopy was assessed. RESULTS: Angles between the IVC and IVST (44.4 ± 5.9° vs. 50.2 ± 6.8°) and IVC and RVA (52.5 ± 5.3° vs. 58.8 ± 7.8°) on CT were significantly (p < 0.01) smaller in the α-loop group. To predict the α-loop shape, a combined IVC-IVST angle < 50° and IVC-RVA angle < 55° revealed higher sensitivity (81.8%). The delivery sheath positioned right of the vertical line was more frequent in the α-loop group (90.9% vs. 23.1%, p < 0.01). CONCLUSIONS: When the preoperatively calculated angles of IVC to IVST and RVA on CT were narrow, the right side of the sheath in the IVC from the vertical line drawn from the deflection point in the LAO view indicated the need to shape the delivery sheath head into an α-loop during LP implantation.

Perovskite-Type InCoO3 with Low-Spin Co3+: Effect of In-O Covalency on Structural Stabilization in Comparison with Rare-Earth Series.

Perovskite rare-earth cobaltites ACoO3 (A = Sc, Y, La-Lu) have been of enduring interest for decades due to their unusual structural and physical properties associated with the spin-state transitions of low-spin Co3+ ions. Herein, we have synthesized a non-rare-earth perovskite cobaltite, InCoO3, at 15 GPa and 1400 °C and investigated its crystal structure and magnetic ground state. Under the same high-pressure and high-temperature conditions, we also prepared a perovskite-type ScCoO3 with an improved cation stoichiometry in comparison to that in a previous study, where synthesis at 6 GPa and 1297 °C yielded a perovskite cobaltite with cation mixing on the A-site, (Sc0.95Co0.05)CoO3. The two perovskite phases have nearly stoichiometric cation compositions, crystallizing in the orthorhombic Pnma space group. In the present investigation, comprehensive studies on newly developed and well-known Pnma ACoO3 perovskites (A = In, Sc, Y, Pr-Lu) show that InCoO3 does not fulfill the general evolution of crystal metrics with A-site cation size, indicating that InCoO3 and rare-earth counterparts have different chemistry for stabilizing the Pnma structures. Detailed structural analyses combined with first-principles calculations reveal that the origin of the anomaly for InCoO3 is ascribed to the A-site cation displacements that accompany octahedral tilts; despite the highly tilted CoO6 network, the In-O covalency makes In3+ ions reluctant to move from their ideal cubic-symmetry position, leading to less orthorhombic distortion than would be expected from electrostatic/ionic size mismatch effects. Magnetic studies demonstrate that InCoO3 and ScCoO3 are diamagnetic with a low-spin state of Co3+ below 300 K, in contrast to the case of (Sc0.95Co0.05)CoO3, where the high-spin Co3+ ions on the A-site generate a large paramagnetic moment. The present work extends the accessible composition range of the low-spin orthocobaltite series and thus should help to establish a more comprehensive understanding of the structure-property relation.

Impact of right ventricular involvement on the prognosis of takotsubo cardiomyopathy.

BACKGROUND: Previous studies showed that patients with takotsubo cardiomyopathy had a higher long-term mortality rate than the general population and the incidence of in-hospital complications was higher in takotsubo cardiomyopathy with than without right ventricular (RV) involvement. This study was performed to investigate the long-term prognostic impact of RV involvement in takotsubo cardiomyopathy. METHODS AND RESULTS: The clinical data of 113 patients (72.7 ± 11.4 years old, 84 females) with takotsubo cardiomyopathy were studied retrospectively. The patients were divided into two groups according to the presence (biventricular group, n = 21, 18.6%) or absence (classical group, n = 92, 81.4%) of RV involvement assessed by initial echocardiography. The end point was a composite of all-cause death, re-hospitalization due to heart failure, and recurrence of takotsubo cardiomyopathy. The in-hospital mortality rate was significantly higher in the biventricular group than the classical group (14.3 vs. 1.1%, respectively, P = 0.02). Kaplan-Meier analysis indicated a significantly lower event-free survival rate in the biventricular group than the classical group (log-rank, P < 0.001). On multivariate analysis, RV involvement was the only independent predictor of the end point (HR: 2.73, P = 0.026). CONCLUSION: The rates of in-hospital and long-term events were significantly higher in takotsubo cardiomyopathy with than without RV involvement, and RV involvement was the independent predictor of the poor prognosis.

Room-temperature polar ferromagnet ScFeO3 transformed from a high-pressure orthorhombic perovskite phase.

Multiferroic materials have been the subject of intense study, but it remains a great challenge to synthesize those presenting both magnetic and ferroelectric polarizations at room temperature. In this work, we have successfully obtained LiNbO3-type ScFeO3, a metastable phase converted from the orthorhombic perovskite formed under 15 GPa at elevated temperatures. A combined structure analysis by synchrotron X-ray and neutron powder diffraction and high-angle annular dark-field scanning transmission electron microscopy imaging reveals that this compound adopts the polar R3c symmetry with a fully ordered arrangement of trivalent Sc and Fe ions, forming highly distorted ScO6 and FeO6 octahedra. The calculated spontaneous polarization along the hexagonal c-axis is as large as 100 µC/cm(2). The magnetic studies show that LiNbO3-type ScFeO3 is a weak ferromagnet with TN = 545 K due to a canted G-type antiferromagnetic ordering of Fe(3+) spins, representing the first example of LiNbO3-type oxides with magnetic ordering far above room temperature. A comparison of the present compound and rare-earth orthorhombic perovskites RFeO3 (R = La-Lu and Y), all of which possess the corner-shared FeO6 octahedral network, allows us to find a correlation between TN and the Fe-O-Fe bond angle, indicating that the A-site cation-size-dependent octahedral tilting dominates the magnetic transition through the Fe-O-Fe superexchange interaction. This work provides a general and versatile strategy to create materials in which ferroelectricity and ferromagnetism coexist at high temperatures.

Impact of target lesion coronary calcification on stent expansion.

BACKGROUND: Stent underexpansion remains a concern as a cause of drug-eluting stent (DES) failure. Although coronary calcification is considered to be a contributing factor in stent underexpansion, previous intravascular ultrasound studies have failed to demonstrate this relationship. We investigated whether stent expansion could be predicted by coronary calcification as assessed by optical coherence tomography (OCT). METHODS AND RESULTS: We enrolled 51 de novo native coronary artery lesions treated by a single 2nd-generation DES (3 types). Prior to stent deployment, the arc and area of calcium at the target lesion were measured using OCT. After successful stent implantation, OCT imaging was repeated to assess minimal stent diameter and area (MSD and MSA). Stent expansion was defined as MSD (or MSA) divided by the values predicted by the manufacturers' compliance charts. Patients were divided into 4 groups according to the median values of the arc and area of calcium. Mean stent expansion was 73.3±8.7% for MSD and 65.2±12.0% for MSA. Stent expansion defined by MSD was significantly different among the 4 groups (P=0.02). A similar trend was observed for stent expansion defined by MSA (P=0.16). CONCLUSIONS: The extent of target lesion calcification as assessed by OCT may be an important determinant of the expansion of 2nd-generation DES.

Impact of energy loss index on left ventricular mass regression after aortic valve replacement.

BACKGROUND: Recently, the energy loss index (ELI) has been proposed as a new functional index to assess the severity of aortic stenosis (AS). The aim of this study was to investigate the impact of the ELI on left ventricular mass (LVM) regression in patients after aortic valve replacement (AVR) with mechanical valves. METHODS: A total of 30 patients with severe AS who underwent AVR with mechanical valves was studied. Echocardiography was performed to measure the LVM before AVR (pre-LVM) (n = 30) and repeated 12 months later (post-LVM) (n = 19). The ELI was calculated as [effective orifice area (EOA) × aortic cross sectional area]/(aortic cross sectional area - EOA) divided by the body surface area. The LVM regression rate (%) was calculated as 100 × (post-LVM - pre-LVM)/(pre-LVM). A cardiac event was defined as a composite of cardiac death and heart failure requiring hospitalization. RESULTS: LVM regressed significantly (245.1 ± 84.3 to 173.4 ± 62.6 g, P < 0.01) at 12 months after AVR. The LVM regression rate negatively correlated with the ELI (R = -0.67, P < 0.01). By receiver operating characteristic (ROC) curve analysis, ELI <1.12 cm(2)/m(2) predicted smaller (<-30.0 %) LVM regression rates (area under the curve = 0.825; P = 0.030). Patients with ELI <1.12 cm(2)/m(2) had significantly lower cardiac event-free survival. CONCLUSION: The ELI as well as the EOA index (EOAI) could predict LVM regression after AVR with mechanical valves. Whether the ELI is a stronger predictor of clinical events than EOAI is still unclear, and further large-scale study is necessary to elucidate the clinical impact of the ELI in patients with AVR.

Prediction of congestive heart failure in patients with non valvular atrial fibrillation.

OBJECTIVE: Patients with atrial fibrillation (AF) have an increased risk of congestive heart failure (CHF) as well as ischemic stroke. The aim of this study was to investigate the clinical predictors of CHF in patients with non-valvular AF (NVAF). METHODS: Three hundred and forty-seven patients (derivation cohort) with NVAF were retrospectively evaluated between 2004 and 2005. The associations between potential risk factors and CHF were tested using a Cox proportional hazards analysis, and a risk score for predicting CHF was created. The model was then validated in 161 patients (validation cohort) enrolled between 2008 and 2010. During the follow-up period, 41 patients in the derivation cohort developed CHF requiring hospitalization due to New York Heart Association (NYHA) class III or IV disease. Four independent risk factors were identified, each of which was assigned a number of points as follows: Age ≥72 years (1 point), heart rate ≥80 bpm (1 point), hypertension (1 point), and a previous history of congestive heart failure (2 points). The patients were grouped into one of three risk categories according to the calculated risk score (ARC2H score): low risk (0 points), intermediate risk (1-3 points) and high risk (4-5 points). RESULT: In the derivation cohort, the annual rates of CHF in these risk categories were 0%, 2.5% and 18% per year respectively. In the validation cohort, the corresponding rates were 0.8%, 8% and 35% per year respectively. CONCLUSION: A simple clinical risk score, the ARC2H score, was developed to predict CHF in patients with NVAF and validated in an independent cohort.

A comparison between 40 MHz intravascular ultrasound iMap imaging system and integrated backscatter intravascular ultrasound.

BACKGROUND: iMap is a newly developed intravascular ultrasound (IVUS) tissue characterization system based on pattern recognition of the radio frequency (RF) signals. PURPOSE: The purpose of this study was to compare tissue characterization between iMap and another previously validated tissue characterization system, integrated backscatter (IB)-IVUS in vivo and to clarify similarities and differences between these two methods. METHODS: A total of 31 lesions from 16 patients with ischemic heart disease were studied. IVUS imaging was performed using 40 MHz IVUS catheter. RF signals from each lesion were then exported to analyze tissue characterization using both iMap and IB-IVUS. By iMap, coronary plaque was classified into four categories, fibrotic, lipidic, necrotic, or calcified. By IB-IVUS, coronary plaque was classified into four categories, fibrosis, lipid pool, dense fibrosis, or calcification. After the images were acquired, IB-IVUS and iMap images were compared at exactly the same cross-sections. Because severe calcification is a perfect reflector, dense calcification lesions (>20%) were excluded. RESULTS: Both fibrotic and calcified by iMap correlated well with fibrosis and calcification by IB-IVUS (fibrotic vs. fibrosis: r(2)=0.522, p<0.001, calcified vs. calcification: r(2)=0.560, p<0.001). Although lipidic by iMap did not correlate with lipid pool by IB-IVUS, necrotic by iMap correlated well with lipid pool by IB-IVUS (r(2)=0.480, p<0.001). CONCLUSION: Although tissue types classified by iMap correlated well with corresponding tissue type by IB-IVUS, some discrepancy presented between the two systems. These results may call for careful interpretation of the tissue types obtained by the different IVUS tissue characterization systems.