M-beat-A novel marker for selective left bundle branch capture.

Template Beat: A Novel Marker for Left Bundle Branch Capture During Physiological Pacing.

B-011-23 QRS CHARACTERISTICS DURING LEFT BUNDLE BRANCH PACING WITH AND WITHOUT BIDIRECTIONAL LEFT INTRAHISIAN BLOCK

A Continuous Pacing and Recording Technique for Differentiating Left Bundle Branch Pacing From Left Ventricular Septal Pacing: Electrophysiologic Evidence From an Intrapatient-Controlled Study.

Left bundle branch pacing (LBBP) is emerging as a novel option for physiological ventricular pacing. The impact of current of injury (COI) at left bundle branch (LBB) has not been previously evaluated. Consecutive patients with QRS duration less than 120 milliseconds referred for LBBP in whom LBB potentials were recorded were included from August 2018 to March 2019. We recorded LBB COI during LBBP and assessed its impact on the pacing parameters and complications during implantation and at short term follow-up. A total of 115 patients with an identifiable LBB potential at implant were included. LBB COI was confirmed in 77 (67.0%) of these patients. Three types of LBB COI were observed. LBB was captured in all patients at a pacing threshold less than 1.5 V/0.5 ms in COI(+) patients, while present in only 29 patients without an LBB COI(-) (100% vs 76.3%; P < .001). There was no significant difference between COI(+) and COI(-) patients in LBB bundle capture threshold (0.64 ± 0.24 vs 0.74 ± 0.26 V/0.5 ms). Selective LBBP was more common in COI(+) group than COI(-) group (54.5% vs 0%; P < .001). Pacing parameters were stable and no lead perforation or dislodgements were observed during follow-up. LBB COI is commonly observed during LBBP in cases with an identifiable LBB potential and can be associated with a low LBB capture threshold and demonstrable selective capture of the LBB acutely and during follow-up. A COI does not preclude safe and stable LBBP pacing.

Background: Although left bundle branch pacing (LBBP) has emerged as a novel physiological pacing strategy, it is still challenging in cases with tricuspid valve disease. Meanwhile, the influence of LBBP lead on tricuspid regurgitation has not been well established in these patients. In the present study, we evaluate the feasibility and safety of LBBP in patients with tricuspid valve disease. Methods: We enrolled 24 patients with tricuspid valve disease who received LBBP procedure in Zhongshan Hospital, Fudan University, between January 2018 and July 2020. Regular follow-ups were conducted (at 1 and 12 months), and the echocardiography data of the patients were collected and analyzed. Results: One postoperative lead dislodgements (1/24, 4.2%) occurred during the follow-up. Mean fluoroscopy time of placing LBBP lead was 19.75±08.23 minutes. Mean follow-up period was 9.64±4.17 months. Pacing parameters were stable during follow-up in all cases. The severity of tricuspid regurgitation(TR) (no 0, slight 1. mild 2, medium 3 and severe 4) under echocardiography were measured and compared at baseline and 1-year follow-up post-procedure. No significant aggravation occurred (2.88±1.57 vs 3.00±1.44, P=0.13). Left ventricular ejection fraction remain stable from baseline to 1-year follow-up(56.27±11.73% vs 59.30±8.17%, P=0.09). Conclusion: LBBP was feasible and safety in patients with tricuspid valve disease though these cases were always challenging such as longer fluoroscopy time, more technocratic requirements, higher rates of failure and procedure-related complications than HBP. Lead parameters were stable during follow-up. No significant aggravation of TR was found.

IntroductionLeft bundle branch (LBB) pacing (LBBP) demonstrates clinical potential but faces challenges in confirming selective capture via dynamic electrogram (EGM) criteria.Case reportA 69-year-old male with a complete atrioventricular block underwent LBBP implantation. Real-time EGM monitoring (high-pass/low-pass filters: 200/500 Hz) revealed an abrupt shortening of stimulus-to-V6 R-wave peak time (Sti-V6 RWPT) from 87 to 69 ms during lead deployment, indicating a transition from septal pacing to LBBP. Output reduction (1.6 V → 1.5 V/0.5 ms) eliminated myocardial excitation notches, yielding isoelectric EGMs confirming selective LBB capture. Further output reduction (1.4 V → 1.3 V/0.5 ms) prolonged Sti-V6 RWPT to 90 ms with an isoelectric interval, suggesting fascicular-level conduction delay.ConclusionThis case report illustrates the electrophysiological features of a diseased conduction system via dynamic EGM analysis, despite technical limitations such as signal artifacts. While EGM morphological patterns assist in differentiating pacing modalities, further validation of these electrophysiological observations is necessary.

A 64-year-old man underwent implantation of a permanent His-bundle pacemaker. A marked rise in the selective His-bundle capture threshold was noted 1 month after the patient started flecainide acetate for rhythm control of recurrent, symptomatic atrial flutter and atrial fibrillation. The capture threshold subsequently normalized 4 days after discontinuing flecainide and switching to dofetilide. To our knowledge, this is the first documented case of a rise in selective His-bundle capture threshold associated with flecainide acetate. Further studies are needed to characterize this association which could result in higher capture thresholds, decreased battery longevity, and mimic His-bundle lead failure.

ObjectivesTo develop and evaluate the classification accuracy of a computable phenotype for pediatric Crohn's disease using electronic health record data from PEDSnet, a large, multi‐institutional research network and Learning Health System.Study DesignUsing clinician and informatician input, algorithms were developed using combinations of diagnostic and medication data drawn from the PEDSnet clinical dataset which is comprised of 5.6 million children from eight U.S. academic children's health systems. Six test algorithms (four cases, two non‐cases) that combined use of specific medications for Crohn's disease plus the presence of Crohn's diagnosis were initially tested against the entire PEDSnet dataset. From these, three were selected for performance assessment using manual chart review (primary case algorithm, n = 360, primary non‐case algorithm, n = 360, and alternative case algorithm, n = 80). Non‐cases were patients having gastrointestinal diagnoses other than inflammatory bowel disease. Sensitivity, specificity, and positive predictive value (PPV) were assessed for the primary case and primary non‐case algorithms.ResultsOf the six algorithms tested, the least restrictive algorithm requiring just ≥1 Crohn's diagnosis code yielded 11 950 cases across PEDSnet (prevalence 21/10 000). The most restrictive algorithm requiring ≥3 Crohn's disease diagnoses plus at least one medication yielded 7868 patients (prevalence 14/10 000). The most restrictive algorithm had the highest PPV (95%) and high sensitivity (91%) and specificity (94%). False positives were due primarily to a diagnosis reversal (from Crohn's disease to ulcerative colitis) or having a diagnosis of “indeterminate colitis.” False negatives were rare.ConclusionsUsing diagnosis codes and medications available from PEDSnet, we developed a computable phenotype for pediatric Crohn's disease that had high specificity, sensitivity and predictive value. This process will be of use for developing computable phenotypes for other pediatric diseases, to facilitate cohort identification for retrospective and prospective studies, and to optimize clinical care through the PEDSnet Learning Health System.

Radiographic findings in young children with physiological bowing sometimes difficult to distinguish from early Blount disease. However, early diagnosis of the disease is critical because of the poor treatment outcomes for Blount disease. In this study, we aim to evaluate the accuracy of the metaphyseal-diaphyseal angle (MDA) compared with the medial metaphyseal beak (MMB) angle for differentiating between physiological bowing and early Blount disease and to determine which parameter to adequately screen for the subsequent development of Blount disease. A retrospective study was conducted on children aged 1 to 3 years old who were brought to our outpatient clinic with bowed leg between 2000 and 2017. Data on the patients' age, sex, and affected sides were collected. Radiographic measurements of the femorotibial angle (FTA), MDA, and MMB angle were evaluated from the initial radiographs. An observer repeated the measurements on all the radiographs 2 weeks after they were first done. In total, 158 legs were considered from 79 children (48 males/31 females), whose average age was 26.0±6.1 months old. Eighty-seven legs were diagnosed with Blount disease and 71 legs had physiological bowing. Using single cutoff values of 16 degrees for the MDA showed low sensitivity (50.6%), very high specificity (100.0%), and a very high positive predictive value (PPV); while using MMB angle cutoff values ≥122 degrees showed very high sensitivity (92.0%), high specificity (80.3%), and a high PPV. Considering the MDA and MMB angle simultaneously showed very high sensitivity (93.1%), high specificity (80.3%), and a high PPV. The area under the receiver operating characteristic curve of the MDA and MMB showed excellent (0.89) and outstanding (0.93) discriminative ability, respectively. When combining the MDA and MMB angles, it was also considered outstanding performance (area under the receiver operating characteristic curve=0.95). The MMB angle represents a potential radiographic screening parameter for predicting early Blount disease in children 1 to 3 years old, offering high sensitivity and specificity. The MDA showed excellent specificity as a confirmation parameter for Blount disease patients. Applying both the MDA and MMB angles is another option to increase early recognition and confirm the diagnosis in early Blount disease patients. Level II.

A simple laboratory measurement for discrimination of transudative and exudative pleural effusion: Pleural viscosity

In a companion article we have reported the prevalence, in an older, defined population, of traditional assessments (intermittent claudication and abnormal pulse examination) of peripheral arterial disease (PAD) as compared with the results of highly accurate noninvasive testing. In this article we report the sensitivity, specificity, and positive and negative predictive values for claudication and abnormal pulses for the diagnosis of large-vessel and small-vessel PAD as determined by noninvasive testing. Claudication and abnormal pulses were completely unrelated to isolated small-vessel PAD. In contrast, both claudication and abnormal pulses were significantly correlated with large-vessel PAD. Claudication and an abnormal femoral pulse showed a high specificity and positive predictive value but a low sensitivity for large-vessel PAD. Conversely, an abnormal dorsalis pedis pulse showed a good sensitivity but low specificity and positive predictive value. The best single discriminator was an abnormal posterior tibial pulse, which had high sensitivity, specificity, and positive predictive value. Various combinations of claudication and pulse abnormalities revealed a good sensitivity for broader criteria but at the expense of specificity, whereas stricter criteria had a good specificity and positive predictive value but a poor sensitivity. No combination was superior to an abnormal posterior tibial pulse alone.(ABSTRACT TRUNCATED AT 250 WORDS)

Introduction: Purulent lobar pneumonia is an inflammation of pulmonary tissue that may progress to parenchymal necrosis and abscess formation. The authors present a case of purulent lobar pneumonia diagnosed using transthoracic lung ultrasound (TLU). Abscess-type lesions had not been visualized in previous computed tomography (CT) scans. Aim: To analyze the potential of TLU as a diagnostic tool for purulent lobar pneumonia. Case study: A 55-year-old patient with a several-week history of cough, abdominal pain, and diarrhea was admitted to the intensive care unit due to rapidly progressing cardiopulmonary failure. CT revealed merging parenchymal/interstitial densities within the right lung. Broad-spectrum antibiotics were initiated. TLU revealed the presence of lesions characteristic of pneumonia with the development of abscesses and acute respiratory distress syndrome. Despite treatment initiation, the patient’s condition progressively worsened. On the 3rd day of hospitalization, the patient passed away. At autopsy, purulent lobar pneumonia was identified as the direct cause of death. Results and discussion: Despite broad and well-documented knowledge regarding its applicability, ultrasound has not been widely used as a diagnostic tool. Conclusions: TLU is a safe, repeatable, and inexpensive diagnostic tool. The use of ultrasound in diagnosing pneumonia is well documented, and based on specific diagnostic criteria. As a diagnostic tool for pneumonia, dynamic air bronchogram had a high specificity and positive predictive value. The high sensitivity and specificity of TLU, as pertains to detecting necrosis or abscesses in the course of pneumonia, is comparable with CT. TLU facilitated visualization of small-diameter abscesses.

Screening test sorts out from apparently healthy population those who probably have the disease or risk factor. Screening test is quick, less accurate, inexpensive and simple to be conducted by technicians, thereby saving doctors time who only interprets the test. Those confirmed by the diagnostic test as cases are given treatment to alter the natural history of disease. This case detection as a result of screening is called prescriptive screening which is superior from case finding where the people are the health care seekers. Also it is different from prospective screening done to protect local population from immigrants having disease. Selective screening in high risk population gives better yield than mass screening. Screening is helpful in education and awareness of general public about diseases and also helps in epidemiological research by cross-sectional and longitudinal surveys. Screening is the main tool in the hands of epidemiologist to detect tuberculosis, diabetes, hypertension, cancer like chronic diseases presenting in community as ‘tip of the ice-berg’. Screening is helpful only in diseases of public health importance having increase prevalence and having time lag between onset and time of diagnosis (latent or asymptomatic period). Diseases must have known natural history, with availability of screening test, diagnostic test and treatment along with resources for sustained care. Also there must be available a clear policy of treatment. There must be good evidence that screening decreases morbidity and mortality of disease along with cost benefit analysis. Screening test must be acceptable for community participation, repeatable (reliable/ precise) like height and weight &amp; not like BP measurement, which has all three sources of errors (intra/ inter observer, subject and technical). The screening test must be valid (accurate) having high sensitivity, specificity, positive and negative predictive value. High sensitivity means increase number of true positive and decreased false negative to avoid false assurance to the patients specially having lethal diseases like cancer versus diabetes which requires less sensitive and highly specific test. High specificity means increased true negative and decreased false positive to keep the image of screening program high as fewer anxious people will require confirming the diagnosis and our diagnostic system will not be overburdened. Sensitivity and specificity are inversely related. Those actually deserving should be screened instead of volunteers. Participants need to be explained the possibility of false positive and false negative. To evaluate screening programs at the place where these are going on, case control, uncontrolled trials and RCTs may be conducted. The response rate is 50 to 60 percent in developed countries. The screening must be done in high risk groups instead of mass level screening for high yield with high predictive value of positive and negative screening test. Screening must be integrated into health care services.

To examine the clinical significance of the Vesical Imaging-Reporting and Data System (VI-RADS) in predicting outcome of multimodal treatment (MMT) in muscle-invasive bladder cancer (MIBC) patients. We reviewed 78 pathologically proven MIBC patients who underwent MMT including transurethral resection and chemoradiotherapy, followed by partial or radical cystectomy. Treatment response was assessed through histologic evaluation of cystectomy specimens. Two radiologists categorized the index lesions of pretherapeutic MRI according to the 5-point VI-RADS score. The associations of VI-RADS score with the therapeutic effect of MMT were analyzed. The diagnostic performance of VI-RADS scores with a cut-off VI-RADS scores ≤ 2 or ≤ 3 for predicting pathologic complete response to MMT (MMT-CR) was evaluated. MMT-CR was achieved in 2 (100%) of VI-RADS score 1 (n = 2), 16 (84%) of score 2 (n = 19), 12 (86%) of score 3 (n = 14), 7 (64%) of score 4 (n = 11), and 14 (44%) of score 5 (n = 32). VI-RADS score was inversely associated with the incidence of MMT-CR (p = 0.00049). The cut-off VI-RADS score ≤ 2 and ≤ 3 could predict the favorable therapeutic outcome of MMT with high specificity (0.89 with 95% confidence interval [CI]: 0.71-0.98 and 0.82 with 95% CI: 0.62-0.94, respectively) and high positive predictive value (0.86 with 95% CI: 0.64-0.97 and 0.86 with 95% CI: 0.70-0.95, respectively). VI-RADS score may serve as an imaging marker in MIBC patients for predicting the therapeutic outcome of MMT. Muscle-invasive bladder cancer patients with a lower Vesical Imaging-Reporting and Data System score can be a good candidate for bladder-sparing treatment incorporating multimodal treatment. • Vesical Imaging-Reporting and Data System (VI-RADS) score was potentially valuable for classifying pathologic tumor response in patients with muscle-invasive bladder cancer. • The likelihood of achieving complete response of multimodal treatment (MMT) decreased with increasing VI-RADS score. • VI-RADS score could serve as an imaging marker that optimizes patient selection for MMT.

Tc-99m sestamibi is known to concentrate in bronchogenic cancer but it lacks the anatomic details for proper management of the patient. Tc-99m MIBI SPECT imaging can detect bronchogenic cancer with high specificity and high positive predictive value. Tc-99m sestamibi SPECT/CT was performed with a gamma camera mounted anatomic x-ray tomography (GMAXT-GE Medical Systems, Millenium VG with Hawkeye). For comparison with GMAXT, additional high-resolution CT of the mediastinum was performed. Correct preoperative localization was achieved: The lesions found on the MIBI scan were found to be located in the right lung. Apart from this, another lesion was noted on the MIBI scan. On fusion images, this lesion was found to be in the right anterior axillary fold. CT-nuclear medicine fusion imaging guided fine needle aspiration cytology done from the lesion in the axillary fold gave a diagnosis of metastatic adenocarcinoma. This was later confirmed by surgical biopsy of the lymph node. Later biopsy reports on bronchoscopy confirmed the lung lesion to be adenocarcinoma.