Usefulness of P-wave peak time as an electrocardiographic parameter in predicting left ventricular diastolic dysfunction in patients with mitral regurgitation.

INTRODUCTION: Conventional Doppler measurements have limitations in predicting left ventricular diastolic dysfunction (LVDD) in patients with mitral regurgitation (MR). Recently, electrocardiographic P-wave peak time (PWPT) has been proposed as a parameter of detecting LVDD. This study aimed to evaluate the association between PWPT and left ventricular end-diastolic pressure (LVEDP) in patients with MR. METHODS: We performed echocardiography and cardiac catheterization in 82 patients with moderate or severe MR. We classified patients into two groups: low LVEDP group (L-LVEDP) (LVEDP <16 mmHg, n = 40) and high LVEDP group (H-LVEDP) (LVEDP ≥16 mmHg, n = 42). We evaluated LVDD and PWPT based on echocardiographic and electrocardiographic findings in both groups. RESULTS: The PWPT in lead II (PWPTII ) was significantly longer in patients in the H-LVEDP group than in those in the L-LVEDP group (67 vs. 47 ms, p < .001). Using correlation analysis, LVEDP was positively correlated with PWPTII (r = .577, p < .001). Using multivariate analysis, PWPTII was found to be an independent predictor of increased LVEDP (95% CI: 0.1030-0.110; p < .001). Using receiver operating characteristic (ROC) curve analysis, the optimal cutoff value of PWPTII for predicting elevated LVEDP was 58.9 ms, with a sensitivity of 80.0% and a specificity of 73.8% (area under curve: 0.809, 95% CI: 0.713-0.905). CONCLUSION: To the best of our knowledge, this is the first study to assess the effect of a significant valvular disease on PWPT in lead II. These findings suggest that prolonged PWPTII may be an independent predictor of increased LVEDP in patients with moderate or severe MR.

Assessing cardiac mechanical dyssynchrony in left bundle branch area pacing and right ventricular septal pacing using myocardial perfusion scintigraphy in the acute phase of pacemaker implantation.

INTRODUCTION: Left bundle branch area pacing (LBBAP) has recently been reported to be a new, clinically feasible and safe physiological pacing strategy. The present study aims to investigate the usefulness of LBBAP in reducing mechanical dyssynchrony compared with right ventricular septal pacing (RVSP). METHODS AND RESULTS: A total of 39 LBBAP patients, 42 RVSP patients, and 93 healthy control participants were retrospectively evaluated. We compared phase analysis- (bandwidth, phase standard deviation [PSD], entropy) and regional wall motion analysis parameters. Wall motion analysis parameters included the time to the end-systolic frame (TES) assessed using single-photon emission computed tomography analysis. The maximum differences between segmental TES (MDTES), the standard deviation of TES (SDTES), and the TES difference between the lateral and septal segments (DTES-LS) were obtained. All phase analysis parameters were significantly smaller in the LBBAP group than in the RVSP group (bandwidth: LBBAP, 74 ± 31° vs. RVSP, 102 ± 59°, p = .009; PSD: LBBAP, 19 ± 6.7° vs. RVSP, 26 ± 15°, p = .007; entropy: LBBAP, 0.57 ± 0.07 vs. RVSP, 0.62 ± 0.11 p = .009). The regional wall motion analysis parameters were also smaller in the LBBAP group than in the RVSP group (MDTES:LBBAP, 17 ± 7.1% vs. RVSP, 25 ± 14%, p = .004; SDTES:LBBAP, 4.5 ± 1.7% vs. RVSP, 6.0 ± 3.5%, p = .015; DTES-LS: LBBAP, 4.1 ± 3.4% vs. RVSP, 7.1 ± 5.4%, p = .004). All phase analysis and wall motion analysis parameters were same in the LBBAP and control groups. CONCLUSION: LBBAP may reduce mechanical dyssynchrony and achieve greater physiological ventricular activation than RVSP.

Impact of the Degree of Wire Bias in the Vessel's Healthy Portion on Coronary Perivascular Trauma in Rotational Atherectomy.

BACKGROUND: In rotational atherectomy (RA), the risk of coronary perforation is considered to increase when the wire is in contact with the healthy portion of the vessel. However, the relationship between the extent of wire bias in the healthy portion of the vessel and the risk of coronary perivascular trauma (CPT) has not been reported. METHODS: We examined 90 consecutive cases wherein intravascular ultrasound (IVUS) was performed before and after RA. The IVUS catheter in contact with the healthy region of the vessel was defined as the healthy portion wire bias (HWB), of which we measured the bias diameter, defined as the media-to-media length between the site where the IVUS catheter was in contact and the opposite side of the vessel. The bias ratio was defined as the ratio of the bias diameter to the short diameter at the region where the wire bias was the strongest. The relationship between the bias ratio and the CPT risk was evaluated. RESULTS: CPT was significantly higher in the HWB group than in the non-HWB group (9% vs. 0%, P = 0.048). In the HWB group, the bias ratio was significantly greater in the CPT group than in the non-CPT group (1.31 ±â€¯0.09 vs. 1.06 ±â€¯0.06; P < 0.0001). The cutoff value of the bias ratio for CPT was 1.2, which was the maximum value of the sum of sensitivity 100% and specificity 97%. CONCLUSIONS: Lesions without HWB had no CPT. CPT risk increased when the bias ratio exceeded 1.2.

Four-dimensional flow magnetic resonance imaging visualizes reverse vortex pattern and energy loss increase in left bundle branch block.

AIMS: This study aimed to investigate the intraventricular blood flow pattern of patients with left bundle branch block (LBBB) using four-dimensional flow magnetic resonance imaging (4D-flow MRI). METHODS AND RESULTS: We performed 4D-flow MRI for 16 LBBB patients (LBBB group) and 16 propensity score-matched patients with a normal QRS duration (non-LBBB group). The energy loss (EL) in the left ventricle was evaluated. In both groups, blood flow from the mitral valve to the apex of the heart and left ventricular (LV) outflow tract during LV diastole were observed. Vortices were also observed in both groups. There were two patterns of vortices: unidirectional clockwise rotation and counterclockwise rotation taking place from the mid-diastole to the systole (reverse pattern). The reverse pattern was observed significantly more frequently in the LBBB group (LBBB 94% vs. non-LBBB 19%, P < 0.001). The interobserver agreement for the streamline analysis was good (kappa = 0.68). The maximum EL was significantly higher in the LBBB group [LBBB 12 (11-15) mW vs. non-LBBB 8.0 (6.2-9.7) mW, P < 0.001]. CONCLUSION: Left bundle branch block patients may suffer from inefficient LV haemodynamics reflected by non-physiological counterclockwise vortices and increased EL. Thus, the shape of the vortices and EL in the left ventricle can serve as markers of LV mechanical dyssynchrony in LBBB patients and could be investigated as predictors of response to cardiac resynchronization therapy.

Concomitant Pulmonary and Cerebral Tumor Embolism and Intracardiac Metastasis from Bladder Cancer.

An 82-year-old woman with a history of bladder cancer presented with dyspnea and loss of consciousness. Contrast-enhanced computed tomography revealed pulmonary embolism, and emergency thrombus aspiration therapy was performed, but the thrombus was not aspirated. Echocardiography showed mobile masses in the heart and a right-to-left shunt due to a patent foramen ovale (PFO). Magnetic resonance imaging showed multiple cerebral infarctions. Surgical thrombectomy and PFO closure were performed, and the patient was diagnosed with intracardiac metastasis of bladder cancer based on intraoperative histopathology. This is a rare case of concomitant pulmonary and cerebral tumor embolism and intracardiac metastasis from bladder cancer.

An Autopsy Case of Antibody-negative Immune-mediated Necrotizing Myopathy with Severe Cardiac Involvement.

A 41-year-old man was admitted with a chief complaint of dyspnea. Echocardiography showed diffuse severe hypokinesis in the left ventricle. Although his heart failure improved, high creatine kinase levels persisted. A muscle biopsy of the biceps brachii showed necrotic and regenerating fibers along with positive findings for major histocompatibility complex class I and membrane attack complex. He was diagnosed with antibody-negative immune-mediated necrotizing myopathy (IMNM). Steroid therapy was started, but he died due to ventricular fibrillation. Autopsy findings revealed CD68-positive macrophages in the myocardium and quadriceps. To our knowledge, this is the first case of antibody-negative IMNM with cardiac involvement.

The usefulness of a delivery catheter system for right ventricular "true" septal pacing.

Right ventricular (RV) septum is an alternate site for the placement of RV lead tip instead of RV apex. Recent studies have demonstrated that less than half of the RV leads targeted for septal implantation are placed on the RV septum using a conventional stylet system; new guiding catheter systems have become available for RV lead placement. This study aimed to investigate the usefulness of the delivery catheter system in lead placement on the RV septum when compared with the stylet system. We retrospectively evaluated 198 patients who underwent fluoroscopically guided pacemaker implantation with RV leads targeted to be placed in the RV septum and in whom computed tomography was incidentally and subsequently performed. A delivery catheter was used in 16 patients, and a stylet in 182 patients. The primary endpoint of this study was the success rate of RV lead placement on the RV septum. The proportion of RV lead placement on the RV septum was higher in the delivery catheter group than in the stylet group (100% vs. 44%; p < 0.001). In the stylet group, the lead tips were placed at the hinge in 92 cases (51%) and on the free wall in 9 cases (5%). Paced QRS duration was narrower in the delivery catheter group than in the stylet group (128 ± 16 vs. 150 ± 21 ms, p < 0.01). The delivery catheter system designated for pacing leads may aid in selecting RV septal sites and achieve good physiologic ventricular activation.