Myeloid Cell Derived IL1ß Contributes to Pulmonary Hypertension in HFpEF.

BACKGROUND: Pulmonary hypertension (PH) in heart failure with preserved ejection fraction (HFpEF) is a common and highly morbid syndrome, but mechanisms driving PH-HFpEF are poorly understood. We sought to determine whether a well-accepted murine model of HFpEF also displays features of PH, and we sought to identify pathways that might drive early remodeling of the pulmonary vasculature in HFpEF. METHODS: Eight-week-old male and female C57BL/6J mice received either Nγ-nitro-L-arginine methyl ester and high-fat diet or control water and diet for 2, 5, and 12 weeks. The db/db mice were studied as a second model of HFpEF. Early pathways regulating PH were identified by bulk and single-cell RNA sequencing. Findings were confirmed by immunostain in lungs of mice or lung slides from clinically performed autopsies of patients with PH-HFpEF. ELISA was used to verify IL-1ß (interleukin-1 beta) in mouse lung, mouse plasma, and also human plasma from patients with PH-HFpEF obtained at the time of right heart catheterization. Clodronate liposomes and an anti-IL-1ß antibody were utilized to deplete macrophages and IL-1ß, respectively, to assess their impact on pulmonary vascular remodeling in HFpEF in mouse models. RESULTS: Nγ-nitro-L-arginine methyl ester/high-fat diet-treated mice developed PH, small vessel muscularization, and right heart dysfunction. Inflammation-related gene ontologies were overrepresented in bulk RNA sequencing analysis of whole lungs, with an increase in CD68+ cells in both murine and human PH-HFpEF lungs. Cytokine profiling showed an increase in IL-1ß in mouse and human plasma. Finally, clodronate liposome treatment in mice prevented PH in Nγ-nitro-L-arginine methyl ester/high-fat diet-treated mice, and IL-1ß depletion also attenuated PH in Nγ-nitro-L-arginine methyl ester/high-fat diet-treated mice. CONCLUSIONS: We report a novel model for the study of PH and right heart remodeling in HFpEF, and we identify myeloid cell-derived IL-1ß as an important contributor to PH in HFpEF.

Potential for trans-pulmonary tumor markers in the early diagnosis of lung cancer: a case report.

BACKGROUND: Measurement of tumor markers from peripheral venous blood is an emerging tool to assist in the early diagnosis of lung cancer. Samples from the pulmonary artery and pulmonary artery wedge position (trans-pulmonary samples) are accessible via right-heart catheterization and, by virtue of their proximity to lung tumors, may increase diagnostic yield. CASE PRESENTATION: We report a case of a 64 year-old woman from whom trans-pulmonary samples were obtained and who was diagnosed 16 months later with recurrent metastatic small cell lung cancer. Carcinoembryonic antigen, cytokeratin fragment 21 - 1 (CYFRA), and human epididymis protein 4 (HE4) levels demonstrated increasing concentrations across the pulmonary circulation. These gradients exceeded the assays' coefficient of variation by several-fold. For CYFRA and HE4, pulmonary artery wedge concentrations exceeded peripheral venous levels by more than 10% and peripheral arterial levels were up to 8% higher than peripheral venous levels. CONCLUSIONS: Evaluating the feasibility and utility of trans-pulmonary tumor markers for lung cancer diagnosis in a larger cohort should be considered. The addition of a peripheral arterial sample to standard peripheral venous samples may be a more practical alternative.

Biomarker-specific differences between transpulmonary and peripheral arterial-venous blood sampling in patients with pulmonary hypertension.

Purpose: Transpulmonary biomarkers may provide insight into pulmonary hypertension (PH) pathophysiology, but require cardiac catheterization. We investigated whether the peripheral arterial-venous ratio (PR) could substitute for the transpulmonary ratio (TPR).Materials and methods: Blood from the pulmonary artery (PA), pulmonary arterial wedge (PAW), peripheral venous, and peripheral arterial positions was analysed for ET-1, NT-pro-BNP and cAMP levels in subjects with no PH (n = 18) and PH due to left heart disease (PH-LHD), which included combined pre- and post-capillary PH (Cpc-PH; n = 7) and isolated post-capillary PH (Ipc-PH; n = 9). Bland-Altman comparisons were made between peripheral venous and PA samples and between peripheral arterial and PAW samples. TPR was defined as [PAW]/[PA].Results: For ET-1, Bland-Altman analysis indicated negative bias (-24%) in peripheral arterial compared to PAW concentration and positive bias (23%) in peripheral venous compared to PA concentration. There was <10% absolute bias for NT-pro-BNP and cAMP. For ET-1, there was no difference in PR between Cpc-PH and Ipc-PH (0.87 ± 0.4 vs. 0.94 ± 0.6, p = 0.8), whereas there was a difference in TPR (2.2 ± 1.1 vs. 1.1 ± 0.2, p < 0.05).Conclusions: In PH-LHD, peripheral samples may be inadequate surrogates for transpulmonary samples, particularly when measuring mediators with prominent pulmonary secretion or clearance, such as ET-1.

Signal-averaged P wave area increases during respiratory events in patients with paroxysmal atrial fibrillation and obstructive sleep apnea.

PURPOSE: P wave characteristics change during simulated apneic events in individuals with atrial fibrillation (AF). This study sought to assess whether similar changes occur during nocturnal respiratory events in patients with AF and obstructive sleep apnea (OSA). METHODS: Thirty-five individuals with severe OSA who underwent formal polysomnography and subsequent AF ablation were compared to a matched group without AF. Electrocardiographic segments from each polysomnogram corresponding to the following events were identified: period of wakefulness closest to the initial onset of sleep (baseline-awake), first respiratory event, respiratory event with the lowest nadir oxygen saturation, longest respiratory event, and last respiratory event. Signal-averaged P wave duration and signal-averaged positive P wave area (amplitude*duration for positive P wave amplitudes) were extracted using custom software. P wave characteristics during respiratory events and the baseline-awake condition were compared. RESULTS: Compared to the baseline-awake condition, the signal-averaged positive P wave area was significantly greater during the longest event and the event with the lowest oxygen saturation in those with AF, but not in those without AF. There were no significant differences in signal-averaged P wave duration for any respiratory event compared to the baseline-awake condition, regardless of AF status. CONCLUSION: In patients with paroxysmal AF and obstructive sleep apnea, the signal-averaged positive P wave area is greater during certain respiratory events than during wakefulness. This finding may reflect the acute impact on right atrial volume of increased venous return associated with respiratory events and could be useful to assess AF risk in sleep apnea and to monitor response to treatment.

Pulmonary transit time from contrast echocardiography and cardiac magnetic resonance imaging: Comparison between modalities and the impact of region of interest characteristics.

INTRODUCTION: The degree of correlation of pulmonary transit time (PTT) between contrast echocardiography and cardiac magnetic resonance imaging (MRI) across the spectrum of cardiac disease has not been quantified. In addition, the degree to which PTT estimates are affected by variation in location and size of regions of interest (ROI) is unknown. METHODS: Pulmonary transit time was obtained using an inflection point technique from individuals that underwent contrast echocardiography and cardiac MRI. Right ventricular, left atrial, and left ventricular ROIs were evaluated, and two sizes for each ROI were used. The Spearman correlation coefficient and Bland-Altman analysis were used for comparisons between modalities. Bland-Altman plots were also used to measure the impact of ROI size and location on transit times. RESULTS: Fourteen participants (age: 27-64 years; LV ejection fraction: 30%-60%) underwent both studies a median of 1 week apart. The correlation between modalities was significant for PTT (r = 0.65; P = 0.01) and normalized PTT (r = 0.80; P = 0.001). Cardiac MRI yielded transit times consistently higher than contrast echocardiography (bias ~ 1.4 seconds), but the discordance was not dependent on transit time magnitude. Low bias was observed for comparisons of ROI size and location (<0.5 seconds). CONCLUSIONS: Contrast echocardiography underestimates transit time measurements obtained by cardiac MRI, although the discrepancy was systematic and may have been contributed to by the interval between imaging studies. ROI location and size did not impact transit time values, suggesting that ROIs could be placed without intensive training, a step toward incorporation of real-time PTT measurement into echocardiographic laboratory workflow.

The relationship between pulmonary artery wedge pressure and pulmonary blood volume derived from contrast echocardiography: A proof-of-concept study.

BACKGROUND: Pulmonary transit time (PTT) obtained from contrast echocardiography is a marker of global cardiopulmonary function. Pulmonary blood volume (PBV), derived from PTT, may be a noninvasive surrogate for left-sided filling pressures, such as pulmonary artery wedge pressure (PAWP). We sought to assess the relationship between PBV obtained from contrast echocardiography and PAWP. METHODS: Participants were adult survivors of childhood cancer that had contrast echocardiography performed nearly simultaneously with right-heart catheterization. PTT was derived from time-intensity curves of contrast passage through the right ventricle (RV) and left atrium (LA). PBV relative to overall stroke volume (rPBV) was estimated from the product of PTT and heart rate during RV-LA transit. PAWP was obtained during standard right-heart catheterization. The Spearman correlation coefficient was used to assess the relationship between rPBV and PAWP. RESULTS: The study population consisted of 7 individuals who had contrast echocardiography and right-heart catheterization within 3 hours of each other. There was a wide range of right atrial (1-17 mm Hg), mean pulmonary artery (18-42 mm Hg), and PAW pressures (4-26 mm Hg) as well as pulmonary vascular resistance (<1-6 Wood Units). We observed a statistically significant correlation between rPBV and PAWP (r = .85; P = .02). CONCLUSION: Relative PBV derived from contrast echocardiography correlates with PAWP. If validated in larger studies, rPBV could potentially be used as an alternative to invasively determine left-sided filling pressure.

Documentation of HEART score discordance between emergency physician and cardiologist evaluations of ED patients with chest pain.

INTRODUCTION: A triage cardiology program, in which cardiologists provide consultation to the Emergency Department (ED), may safely reduce admissions. For patients with chest pain, the HEART Pathway may obviate the need for cardiology involvement, unless there is a difference between ED and cardiology assessments. Therefore, in a cohort concurrently evaluated by both specialties, we analyzed discordance between ED and cardiology HEART scores. METHODS: We performed a single-center, cross-sectional, retrospective study of adults presenting to the ED with chest pain who had a documented bedside evaluation by a triage cardiologist. Separate ED and cardiology HEART scores were computed based on documentation by the respective physicians. Discrepancies in HEART score between ED physicians and cardiologists were quantified using Cohen κ coefficient. RESULTS: Thirty-three patients underwent concurrent ED physician and cardiologist evaluation. Twenty-three patients (70%) had discordant HEART scores (κ = 0.13; 95% confidence interval, -0.02 to 0.32). Discrepancies in the description of patients' chest pain were the most common source of discordance and were present in more than 50% of cases. HEART scores calculated by ED physicians tended to overestimate the scores calculated by cardiologists. When categorized into low-risk or high-risk by the HEART Pathway, more than 25% of patients were classified as high risk by the ED physician, but low risk by the cardiologist. CONCLUSION: There is substantial discordance in HEART scores between ED physicians and cardiologists. A triage cardiology system may help refine risk stratification of patients presenting to the ED with chest pain, even when the HEART Pathway tool is used.

Automated detection of atrial fibrillation from the electrocardiogram channel of polysomnograms.

PURPOSE: Accurate identification of atrial fibrillation episodes from polysomnograms is important for research purposes but requires manual review of a large number of long electrocardiographic tracings. As automated assessment of these tracings for atrial fibrillation may improve efficiency, this study aimed to evaluate this approach in polysomnogram-derived electrocardiographic data. METHODS: A previously described algorithm to detect atrial fibrillation from single-lead electrocardiograms was applied to polysomnograms from a large epidemiologic study of obstructive sleep apnea in older men (Osteoporotic Fractures in Men [MrOS] Sleep Study). Atrial fibrillation status during each participant's PSG was determined by independent manual review. Models to predict atrial fibrillation status from a combination of algorithm output and clinical/polysomnographic characteristics were developed, and their accuracy was evaluated using standard statistical techniques. RESULTS: Derivation and validation cohorts each consisted of 1395 individuals; 5 % of each group had atrial fibrillation. Model parameters were optimized for the derivation cohort using the Akaike information criterion. Application to the validation cohort of these optimized models revealed high sensitivity (85-90 %) and specificity (90-95 %) as well as good predictive ability, as assessed by the C statistic (>0.9) and generalized R (2) values (∼0.6). Addition of cardiovascular or polysomnogram data to the models did not improve their performance. CONCLUSIONS: In a research setting, automated detection of atrial fibrillation from polysomnogram-derived electrocardiographic signals appears feasible and agrees well with manual identification. Future studies can evaluate the utility of this technique as applied to clinical polysomnograms and ambulatory electrocardiographic monitoring.

Feasibility and Diagnostic Potential of Pulmonary Transit Time Measurement by Contrast Echocardiography: A Pilot Study.

AIMS: Pulmonary transit time (PTT; the time for ultrasound contrast to travel from the right ventricle [RV] to the left atrium) may provide a single metric that reports on cardiopulmonary function while overcoming some of the challenges of standard echocardiographic measures. We conducted a pilot study to test the feasibility and reproducibility of echocardiographically derived PTT and to determine its association with established measures of cardiopulmonary function. METHODS AND RESULTS: A total of 39 patients receiving clinically indicated ultrasound contrast were prospectively enrolled. PTT was measured in the apical four-chamber view using commercially available software. Reproducibility and inter-observer agreement were assessed in 9 patients. PTT was correlated with established measures of left ventricular systolic and diastolic function, RV function, and pulmonary vascular status. PTT could be measured in 89% (33/37) of patients without a contraindication to ultrasound contrast; all measurements from the last 20 patients were interpretable and obtained independently by a sonographer. Reproducibility and inter-observer agreement were excellent. PTT correlated well with standard echocardiographic indicators of cardiac status. A PTT >4.5 seconds accurately identified all but 1 patient with cardiopulmonary dysfunction. CONCLUSIONS: This pilot study demonstrates that measurement of PTT using ultrasound contrast is highly reproducible, accurately reflects global cardiopulmonary function across a range of cardiopulmonary disease, and can be readily obtained by an independent sonographer. Further studies are needed to determine whether PTT has incremental value in diagnosis and prognosis compared to conventional echocardiographic parameters.

Cerebral, Splanchnic, and Renal Transit Time Measurement and Blood Volume Estimation Using Contrast-Enhanced Ultrasonography.

ABSTRACT: We aimed to measure cerebral, splanchnic, and renal transit times and the associated blood volumes using contrast ultrasound. In healthy individuals, regional transit times were calculated from time-intensity curves generated as ultrasound contrast passed through the associated inflow and outflow vessels. These included the internal carotid artery and internal jugular vein (brain), the superior mesenteric artery and portal vein (intestines), and the renal artery and renal vein (kidney). An organ's blood volume relative to the stroke volume delivered to that organ with each cardiac cycle was calculated from the product of heart rate and transit time of contrast passage through the associated vascular bed. The fraction of systemic stroke volume received by each organ was calculated from the respective velocity-time integral and inflow vessel cross-sectional area and used to estimate absolute organ blood volume. The cohort consisted of 16 participants (age: 42 ± 13 years; 5 female) without known cerebrovascular, gastrointestinal, or renal disease. Cerebral, splanchnic, and renal transit times were obtained for 15, 14, and 8 individuals, respectively. Anatomic variability of the renal vessels confounded the acquisition of renal transit times. For all organs, transit times were reproducible and the associated blood volumes were generally comparable to reference values. Cerebral, gastrointestinal, and renal transit times/blood volumes can be reasonably acquired from contrast ultrasound, although the latter is less reliably available. Assessment of the impact on regional blood volumes of pharmacologic or other interventions is a next step toward clinical application of this technique.

Impact of the COVID-19 Pandemic on Medical Grand Rounds Attendance: Comparison of In-Person and Remote Conferences.

BACKGROUND: Many academic medical centers transitioned from in-person to remote conferences due to the COVID-19 pandemic, but the impact on faculty attendance is unknown. OBJECTIVE: This study aims to evaluate changes in attendance at medical grand rounds (MGR) following the transition from an in-person to remote format and as a function of the COVID-19 census at Vanderbilt Medical Center. METHODS: We obtained the faculty attendee characteristics from Department of Medicine records. Attendance was recorded using a SMS text message-based system. The daily COVID-19 census was recorded independently by hospital administration. The main attendance metric was the proportion of eligible faculty that attended each MGR. Comparisons were made for the entire cohort and for individual faculty. RESULTS: The observation period was from March 2019 to June 2021 and included 101 MGR conferences with more than 600 eligible faculty. Overall attendance was unchanged during the in-person and remote formats (12,536/25,808, 48.6% vs 16,727/32,680, 51.2%; P=.44) and did not change significantly during a surge in the COVID-19 census. Individual faculty members attendance rates varied widely. Absolute differences between formats were less than -20% or greater than 20% for one-third (160/476, 33.6%) of faculty. Pulmonary or critical care faculty attendance increased during the remote format compared to in person (1450/2616, 55.4% vs 1004/2045, 49.1%; P<.001). A cloud-based digital archive of MGR lectures was accessed by <1% of faculty per conference. CONCLUSIONS: Overall faculty attendance at MGR did not change following the transition to a remote format, regardless of the COVID-19 census, but individual attendance habits fluctuated in a bidirectional manner. Incentivizing the use of a digital archive may represent an opportunity to increase faculty consumption of MGR.

Measurement of pulmonary transit time and estimation of pulmonary blood volume after exercise using contrast echocardiography.

BACKGROUND: Pulmonary transit time (PTT) and pulmonary blood volume (PBV) derived from non-invasive imaging correlate with pulmonary artery wedge pressure. The response of PBV to exercise may be useful in the evaluation of cardiopulmonary disease but whether PBV can be obtained reliably following exercise is unknown. We therefore aimed to assess the technical feasibility of measuring PTT and PBV after exercise using contrast echocardiography. METHODS: In healthy volunteers, PTT was calculated from time-intensity curves generated as contrast traversed the cardiac chambers before and immediately after participants performed sub-maximal exercise on the Standard Bruce Protocol. From the product of PTT and heart rate (HR) during contrast passage through the pulmonary circulation, PBV relative to systemic stroke volume (rPBV) was calculated. RESULTS: The cohort consisted of 14 individuals (age: 46 ± 8 years; 2 female) without cardiopulmonary disease. Exercise time was 8 ¾ ± 1 ¾ minutes and participants reached 85 ± 9% of age-predicted maximal HR, which corresponded to a near-doubling of resting HR at the time of post-exercise contrast injection. Data sufficient to derive PTT and rPBV were obtained for all participants. With exercise, the change in PBV from baseline ranged from 56 to 138% of systemic stroke volume, consistent with rPBV and absolute PBV values obtained in prior studies. CONCLUSIONS: Acquisition of PTT and rPBV using contrast echocardiography after exercise is achievable and the results are physiologically plausible. As the next step towards clinical implementation, validation of this technique against hemodynamic exercise studies appears reasonable.

Myeloid Cell Derived IL1ß Contributes to Pulmonary Vascular Remodeling in Heart Failure with Preserved Ejection Fraction.

Background: Pulmonary hypertension (PH) in heart failure with preserved ejection fraction (HFpEF) is a common and highly morbid syndrome, but mechanisms driving PH-HFpEF are not well understood. We sought to determine whether a well-accepted murine model of HFpEF also displays features of PH in HFpEF, and we sought to identify pathways that might drive early remodeling of the pulmonary vasculature in HFpEF. Methods: Eight week old male and female C57/BL6J mice were given either L-NAME and high fat diet (HFD) or control water/diet for 2,5, and 12 weeks. Bulk RNA sequencing and single cell RNA sequencing was performed to identify early and cell-specific pathways that might regulate pulmonary vascular remodeling in PH-HFpEF. Finally, clodronate liposome and IL1ß antibody treatments were utilized to deplete macrophages or IL1ß, respectively, to assess their impact on pulmonary vascular remodeling in HFpEF. Results: Mice given L-NAME/HFD developed PH, small vessel muscularization, and right heart dysfunction after 2 weeks of treatment. Inflammation-related gene ontologies were over-represented in bulk RNA sequencing analysis of whole lungs, with an increase in CD68+ cells in both murine and human PH-HFpEF lungs. Cytokine profiling of mouse lung and plasma showed an increase in IL1ß, which was confirmed in plasma from patients with HFpEF. Single cell sequencing of mouse lungs also showed an increase in M1-like, pro-inflammatory populations of Ccr2+ monocytes and macrophages, and transcript expression of IL1ß was primarily restricted to myeloid-type cells. Finally, clodronate liposome treatment prevented the development of PH in L-NAME/HFD treated mice, and IL1ß antibody treatment also attenuated PH in L-NAME/HFD treated mice. Conclusions: Our study demonstrated that a well-accepted model of HFpEF recapitulates features of pulmonary vascular remodeling commonly seen in patients with HFpEF, and we identified myeloid cell derived IL1ß as an important contributor to PH in HFpEF.

Role of obstructive sleep apnea in cardiovascular disease.

PURPOSE OF REVIEW: To provide an update on the connection between obstructive sleep apnea (OSA) and cardiovascular disease. RECENT FINDINGS: Large prospective studies have established that OSA is associated with an increased incidence of hypertension and, in men, of coronary disease, stroke, and heart failure. Advances in understanding the pathophysiologic basis for these associations include identification of a role for OSA in inducing abnormalities in hepatic lipid-metabolizing enzymes, endothelial dysfunction, and upregulation of pro-inflammatory and pro-thrombotic mediators. A large body of data implicates OSA as playing a significant role in the occurrence and resistance to treatment of atrial fibrillation. Clinical trials have shown small-to-modest improvements in blood pressure associated with continuous positive airway pressure (CPAP) use, with smaller or uncontrolled studies suggesting that CPAP may improve cardiovascular outcomes or intermediate markers. SUMMARY: OSA and cardiovascular disease commonly co-aggregate. Multiple studies indicate that OSA contributes to or exacerbates cardiovascular disease, and thus may be a novel target for cardiovascular risk reduction. Although the evidence supports screening and treatment of OSA in patients at risk for cardiovascular disease, it also underscores a need for well powered clinical trials to examine the role of CPAP and other therapies in these populations.

Potential impact of cardiology phone-consultation for patients risk-stratified by the HEART pathway.

Objective: Bedside consultation by cardiologists may facilitate safe discharge of selected patients from the emergency department (ED) even when admission is recommended by the History, Electrocardiogram, Age, Risk factors, Troponin (HEART) pathway. If bedside evaluation is unavailable, phone consultation between emergency physicians and cardiologists would be most impactful if the resultant disposition is discordant with the HEART pathway. We therefore evaluate discordance between actual disposition and that suggested by the HEART pathway in patients presenting to the ED with chest pain for whom cardiology consultation occurred exclusively by phone and to assess the impact of phone-consultation on disposition. Methods: We performed a single-center, retrospective study of adults presenting to the ED with chest pain whose emergency physician had a phone consultation with a cardiologist. Actual disposition was abstracted from the medical record. HEART pathway category (low-risk, discharge; high-risk, admit) was derived from ED documentation. For discharged patients, major adverse cardiac events were assessed at 30 days by chart review and phone follow-up. Results: For the 170 patients that had cardiologist phone consultation, discordance between actual disposition and the HEART pathway was 17%. The HEART pathway recommended admission for nearly 80% of discharged patients. Following cardiologist phone-consultation, 10% of high-risk patients were discharged, with the majority having undergone a functional study recommended by the cardiologist. At 30 days, discharged patients had experienced no episodes of major adverse cardiac events or rehospitalization for cardiac reasons. Conclusion: For patients presenting to the ED with chest pain, cardiology phone-consultation has the potential to safely impact disposition, primarily by facilitating functional testing in high-risk individuals.

Copy-and-Paste in Medical Student Notes: Extent, Temporal Trends, and Relationship to Scholastic Performance.

BACKGROUND: Medical students may observe and subsequently perpetuate redundancy in clinical documentation, but the degree of redundancy in student notes and whether there is an association with scholastic performance are unknown. OBJECTIVES: This study sought to quantify redundancy, defined generally as the proportion of similar text between two strings, in medical student notes and evaluate the relationship between note redundancy and objective indicators of student performance. METHODS: Notes generated by medical students rotating through their medicine clerkship during a single academic year at our institution were analyzed. A student-patient interaction (SPI) was defined as a history and physical and at least two contiguous progress notes authored by the same student during a single patient's hospitalization. For some students, SPI pairs were available from early and late in the clerkship. Redundancy between analogous sections of consecutive notes was calculated on a 0 to 100% scale and was derived from edit distance, the number of changes needed to transform one text string into another. Indicators of student performance included United States Medical Licensing Exam (USMLE) scores. RESULTS: Ninety-four single SPIs and 58 SPI pairs were analyzed. Redundancy in the assessment/plan section was high (40%) and increased within individual SPIs (to 60%; p < 0.001) and between SPI pairs over the course of the clerkship (by 30-40%; p < 0.001). Students in the lowest tertile of USMLE step II clinical knowledge scores had higher redundancy in the assessment/plan section than their classmates (67 ± 24% vs. 38 ± 22%; p = 0.002). CONCLUSION: During the medicine clerkship, the assessment/plan section of medical student notes became more redundant over a patient's hospital course and as students gained clinical experience. These trends may be indicative of deficiencies in clinical knowledge or reasoning, as evidenced by performance on some standardized evaluations.

Individual periodic limb movements with arousal are temporally associated with nonsustained ventricular tachycardia: a case-crossover analysis.

STUDY OBJECTIVES: Both periodic limb movements during sleep (PLMS) and arousals are associated with sympathetic nervous system activation and may be arrhythmogenic. We hypothesize a temporal relationship exists between individual PLMS, particularly with arousal, and nonsustained ventricular tachycardia (NSVT) events. METHODS: A bidirectional time-stratified case-crossover design was used to assess temporal associations between PLMS and NSVT during sleep in 49 Osteoporotic Fractures in Men Sleep Study participants with NSVT in a community-based cohort (n = 2,911). Sleep time was divided into approximate 30-min segments. For each NSVT (n = 141), we selected a preceding 30-s hazard period and three randomly chosen 30-s control periods from sleep within the same segment and evaluated for PLMS, respiratory events, minimum saturation, and arousals. Odds ratios and 95% confidence intervals-OR (95% CI)-were determined by conditional logistic regression; covariates included EEG arousals, minimum saturation, and respiratory events in the same hazard/control period. RESULTS: Participants with NSVT were 79.5 ± 6.2 years with a PLMS index of 32.1 (IQR: 10.1, 61.4) and apnea-hypopnea index of 17.1 (IQR: 9.4, 26.1). PLMS without arousal were not significantly associated with NSVT (OR = 0.80, 95% CI: 0.41-1.59). PLMS with arousal were associated with NSVT in unadjusted analyses (OR = 2.50, 95% CI: 1.11-5.65) and after adjustment (OR = 2.31, 95% CI: 1.02-5.25). Arousals associated with PLMS were associated with NSVT in unadjusted (OR = 2.84, 95% CI: 1.23-6.56) and adjusted analyses (OR = 2.61, 95% CI: 1.13-6.05). CONCLUSIONS: PLMS with (but not without) arousals are temporally associated with a greater than twofold higher odds of subsequent NSVT episodes. PLMS-related arousals may be physiologically important ventricular arrhythmia triggers. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT00070681.

Schedule-based metrics for the evaluation of clinic performance and potential recovery of cancelled appointments.

BACKGROUND: Assessment of outpatient clinic performance is important to optimize patient access. Metrics based on schedule data may assist with assessment of operational efficiency and recovering cancelled appointments. OBJECTIVES: To define schedule-based characteristics of clinic operations and to evaluate potential for recovery of cancelled appointments. METHODS: Sixty-seven weekly cardiology clinics from a single provider over 18 months at an academic medical center were analyzed. Parameters included clinic slots eligible to have patients scheduled (available), slots occupied by appointments (scheduled), and slots for which patients attended the associated visit (appeared). Rates of usage (scheduled/available), appearance (appeared/scheduled), and utilization (appeared/available=usage rate*appearance rate) were calculated. Surplus slots were defined as the difference between available slots and slots occupied by patients that appeared. Cancellation lag-time was defined as the interval between a cancellation and the appointment time. If a patient did not notify the clinic regarding a non-appearance, cancellation lag-time was set to zero. To quantify the impact of a change in clinic operations on efficiency, these metrics were used to evaluate a different cardiologist's clinic before and after its physical location moved. RESULTS: For approximately 900 patient visits, usage and appearance rates were∼80%, yielding a utilization rate of ∼2/3. On average, there were nearly 8 surplus slots per clinic. Approximately 30% of cancellation lag-times had positive values and nearly half of positive cancellation lag-times were >3h, indicating potential for recovery of those appointments. The intervention analysis showed that usage rate decreased and surplus slots per clinic increased significantly after a change in clinic location. CONCLUSIONS: Schedule-based analysis provides a framework to assess changes to clinic operations, identify mechanisms underlying inefficiency, and suggest solutions for improving clinic performance (i.e. more schedulers in response to low usage rates). Cancellation lag-time analysis suggests recovering a portion of same-day cancellations is plausible.