Myocardial Stunning-Induced Left Ventricular Dyssynchrony On Gated Single-Photon Emission Computed Tomography Myocardial Perfusion Imaging

Objectives Myocardial stunning provides additional nonperfusion markers of coronary artery disease (CAD), especially for severe multivessel CAD. The purpose of this study is to assess the influence of myocardial stunning to the changes of left ventricular mechanical dyssynchrony (LVMD) parameters between stress and rest gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI). Patients and methods A total of 113 consecutive patients (88 males and 25 females) who had undergone both stress and rest 99mTc-sestamibi gated SPECT MPI were retrospectively enrolled. Suspected or known patients with CAD were included if they had exercise stress MPI and moderate to severe myocardial ischemia. Segmental scores were summed for the three main coronary arteries according to standard myocardial perfusion territories, and then regional perfusion, wall motion, and wall thickening scores were measured. Myocardial stunning was defined as both ischemia and wall dysfunction within the same coronary artery territory. Patients were divided into the stunning group (n=58) and nonstunning group (n=55). Results There was no significant difference of LVMD parameters between stress and rest in the nonstunning group. In the stunning group, phase SD and phase histogram bandwidth of contraction were significantly larger during stress than during rest (15.05±10.70 vs. 13.23±9.01 and 46.07±34.29 vs. 41.02±32.16, PP\u3c0.05). Conclusion Both systolic and diastolic LVMD parameters deteriorate with myocardial stunning. This kind of change may have incremental values to diagnose CAD

Renal Denervation Attenuates Multi-Organ Fibrosis and Improves Vascular Remodeling in Rats with Transverse Aortic Constriction Induced Cardiomyopathy

Background/Aims: To investigate the effects of renal denervation (RDN) on multi-organ fibrosis and vascular remodeling in cardiomyopathy. Methods: Thirty-six male Sprague-Dawley rats underwent transverse aortic constriction (TAC). Five weeks later, 28 surviving TAC rats were randomly assigned to three groups: (1) RDN, (2) Sham, (3) Carvedilol. Six male Sham TAC rats served as the Control. Ten weeks after TAC, samples were collected. Results: TAC rats showed an increased diastolic interventricular septal thickness at week 5. At 10 weeks, Masson staining showed that left ventricular and renal glomerular fibrosis were significantly reduced in RDN compared with Sham group. In comparison to Sham group, hepatic perivascular fibrosis was attenuated in both RDN and Carvedilol group, so were the media thickness and the media/lumen of aorta. The plasma levels of B-type natriuretic peptide (BNP), Cystatin C (Cys-C), Alanine Transaminase, angiotensin II (Ang II), transforming growth factor beta 1 (TGF-β1), and malondialdehyde increased, and total superoxide dismutase (T-SOD) decreased in Sham but not in RDN group, compared with Control group. Both RDN and Carvedilol reduced the Cys-C and TGF-β1 levels, and restored T-SOD concentration, compared with Sham group. While only RDN lowered the plasma levels of BNP and Ang II. No significant effects of RDN on blood pressure (BP) and heart rate (HR) were oberved. Conclusions: RDN can attenuate multi-organ fibrosis and improve vascular remodeling independent of BP and HR change in TAC-induced cardiomyopathy. These effects of RDN may be associated with the direct inhibition of renin-angiotensin-aldosterone system and oxidative stress

Reversible T-wave inversions during left bundle branch area pacing

BACKGROUND: Our clinical observation found T-wave inversions (TWIs) appeared during left bundle branch area pacing (LBBAP), however, the incidence and influence factors were unclear. To investigate the effects of LBBAP on T-wave and explore possible factors associated with TWIs. METHODS: This was a retrospective cohort study. Electrocardiogram (ECG) was acquired at baseline and after LBBAP. Baseline characteristics, ECG parameters, LBBAP parameters and troponin T (TNT) levels were compared between non-TWIs and TWIs groups. Multivariable logistic analyses were performed to adjust for potential confounders to identify the predictive factors of TWIs during LBBAP. RESULTS: A total of 398 consecutive patients underwent successful LBBAP were assessed for inclusion between May 2017 and Jan 2021, and 264 (66.3%) patients had TWIs. The mean (standard deviation [SD]) baseline QRS duration (QRSd) was longer in TWIs group compared to non-TWIs group (125.9 [34.5] ms vs. 98.2 [18.1] ms; P <0.001). Multivariable logistic regression analysis suggested that QRSd >120 ms was an independent predictor for TWIs. TWIs were partially or completely recovered in 151/172 (87.8%) patients during follow-up, the median (interquartile range [IQR]), follow-up duration was 10 days (7 days to 5.5 months). TWIs in patients with complete left bundle branch block (CLBBB) occured more frequency in inferior wall leads (II, III and aVF) and anterior wall leads (V1-4) (P <0.05, respectively). Patients with complete right bundle branch block (CRBBB) were more prone to TWIs in high lateral wall leads (I and aVL) (P <0.05, respectively). There were no significant differences of TNT levels between TWIs and non-TWIs groups. CONCLUSIONS: TWIs during LBBAP was clinically frequent can recoverable. QRSd >120 ms was independently associated with TWIs

Feasibility and safety of left bundle branch area pacing in very elderly patients (≥80 years)

Background: Left bundle branch area pacing (LBBAP) has emerged as a promising physiologic pacing strategy. Though many clinical studies have established the feasibility and safety of LBBAP, the data for very elderly patients are lacking.Aims: This study aimed to assess the feasibility and safety of LBBAP in very elderly patients (≥80 years).Methods: Two hundred and forty consecutive patients who received LBBAP implantation were retrospectively enrolled in the present study. Inclusion criteria were patients with atrioventricular block, atrial fibrillation with a slow ventricular response, and heart failure with bundle branch block. The patients were divided into two groups: those aged ≥80 years and those aged <80 years.  LBBAP implantation was successfully performed in 48 of 53 (90.6%) very elderly patients and 162 of 187 (86.5%) counterparts. In the very elderly group, the mean (standard deviation [SD]) age was 84 (3) years, mean (SD) paced QRS duration was 112.4 (9.0), and the mean (SD) stimulus to R wave peak time was 82.0 (14.2) ms. Mean (SD) pacing thresholds and mean (SD) R wave sensing were 0.61(0.21) V and 12.1 (4.7) mV at implant. Pacing parameters in very elderly patients were similar to those in their counterparts. During a median follow-up of 6 months, pacing parameters remained stable. Five patients in the very elderly group developed complications (1 with septal perforation during the procedure, 1 with pocket hematoma, 1 with pacing threshold increase, and 2 with micro lead dislodgement during follow-up).Conclusion: LBBAP is safe and effective in patients ≥80 years old. LBBAP can be considered as an alternative method for delivering physiological pacing in this special population

Preparative Isolation and Purification of Lignans from Justicia procumbens Using High-Speed Counter-Current Chromatography in Stepwise Elution Mode

Lignans, which are recognized as main constituents in Justicia procumbens, have attracted considerable attention due to their pharmacological activities, including antitumor, anti-hepatitic, cytotoxic, anti-microbial, and anti-virus properties. Preparative high-speed counter-current chromatography (HSCCC) was successfully applied to the isolation and purification of four lignans (justicidin B (1), justicidin A (2), 6'-hydroxyjusticidin C (3) and lignan J1 (4)) from J. procumbens using stepwise elution with a pair of two-phase solvent systems composed of n-hexane–ethyl acetate–methanol–water at (1.3:1:1.3:1, v/v) and (2.5:1:2.5:1, v/v). The preparative HSCCC separation was performed on 300 mg of crude sample yielding compounds 1 (19.7 mg), 2 (9.86 mg), 3 (11.26 mg), and 4 (2.54 mg) in a one-step separation, with purities over 95% as determined by HPLC. The structures of these compounds were identified by MS, 1H-NMR and 13C-NMR. This is the first report on the application of HSCCC to the efficient separation of lignans from J. procumbens