The power of three: Atrial rate limit power-on-reset - A non-electromagnetic cause of pacemaker-induced extracardiac stimulation

BACKGROUND

Power-on reset (PoR) is most commonly due to electromagnetic interference. Full PoR results in a switch to an inhibited mode (VVI) pacing and resets pacing outputs to maximal unipolar settings, leading to extracardiac stimulation.

METHODS

We present a case of PoR occurrence in the absence of electromagnetic interference, resulting in pectoral stimulation triggered by violation of the atrial rate limit.

CONCLUSIONS

It is useful for clinicians to recognizethe occurrence of PoR in the setting of atrial limit violation andthe appropriate management in such circumstances.

Late antenatal care initiation and neonatal outcomes in an ethnically diverse maternal cohort

Background

Ethnic minority status and maternal socio-economic deprivation are linked to delayed access to health care during pregnancy. The link between late antenatal care initiation and neonatal outcomes in settings with high ethnic diversity and social disadvantage is seldom explored. This study examined associations between late antenatal care initiation (first antenatal appointment >12 weeks gestation) and neonatal outcomes of preterm birth (<37 weeks gestation) and low birth weight (<2500 g) in an ethnically diverse socially disadvantaged maternal cohort.

Methods

A retrospective cross sectional study using routinely collected anonymous data of singleton births between April 2007 - March 2016 from a large UK National Health Service maternity unit in an ethnically diverse, socially disadvantaged area. Univariate and multivariate logistic regression models were used to examine the associations between late antenatal care initiation and prevalence of preterm birth and low birth weight.

Results

Of the 46,307 singleton births recorded, more than one third (34.8%) were to mothers from Black African, Black Caribbean, Indian, Pakistani, and Bangladeshi mothers. Gestational week at first antenatal appointment was available for 99.31% births among which 79.2% had their first appointment at ≤ 12 weeks, 12% at 13-20 weeks, and 8.8% at > 20 weeks. Mothers who booked at 13+ weeks were significantly more likely to have a preterm and/or low birth weight baby. Compared to mothers who booked at ≤ 12 weeks, those booking at > 20 weeks were 4.08 times (95% CI: 3.29,5.07) as likely to have an extremely preterm baby (<28 weeks of gestation) and 3.12 (CI 2.66, 3.67) times as likely to have a baby born with extremely low birthweight (<1500g).

Conclusions

Mothers in ethnically diverse socially deprived areas who started antenatal care late were at increased risk of adverse neonatal outcomes. Targeted intervention programmes and services are needed to support these mothers.

Key messages

Oral Health in the Population Assessment of Tobacco and Health Study

Tobacco use is a well-established risk factor for multiple adverse oral conditions. Few nationally representative oral health data sets encompass the current diversity of tobacco and nicotine products. This investigation examines the validity of oral health measures in the Population Assessment of Tobacco and Health (PATH) Study to assess relationships between tobacco use and oral health. Cross-sectional data from PATH Study wave 4 (N = 33,643 US adults, collected 2016-2018) were used to obtain estimates for 6 self-reported oral conditions (e.g., bone loss around teeth, tooth extractions) and compared with analogous estimates from the National Health and Nutrition Examination Survey (NHANES) cycle 2017-2018 (N = 5,856). Within the PATH Study, associations were calculated between tobacco use status and lifetime and past 12-mo experience of adverse oral conditions using survey-weighted multivariable logistic regression. Nationally representative estimates of oral conditions between the PATH Study and NHANES were similar (e.g., ever-experience of bone loss around teeth: PATH Study 15.2%, 95% CI, 14.4%-15.9%; NHANES 16.6%, 95% CI, 14.9%-18.4%). In the PATH Study, combustible tobacco smoking was consistently associated with lifetime and past 12-mo experience of adverse oral health (e.g., exclusive cigarette smoking vs. never tobacco use, adjusted odds ratio [AOR] for loose teeth in past 12 mo: 2.02; 95% CI, 1.52-2.69). Exclusive smokeless tobacco use was associated with greater odds of loose teeth (AOR, 1.93; 95% CI, 1.15-3.26) and lifetime precancerous lesions (AOR, 3.85; 95% CI, 1.73-8.57). Use of other noncigarette products (e.g., pipes) was inconsistently associated with oral health outcomes. PATH Study oral health measures closely align with self-reported measures from NHANES and are internally concurrent. Observed associations with tobacco use and the ability to examine emerging tobacco products support application of PATH Study data in dental research, particularly to examine potential oral health effects of novel tobacco products and longitudinal changes in tobacco use behaviors.

Adverse childhood experiences and substance misuse in young people in India: results from the multisite cVEDA cohort

BACKGROUND

Adverse childhood experiences (ACEs) increases vulnerability to externalising disorders such as substance misuse. The study aims to determine the prevalence of ACEs and its association with substance misuse.

METHODS

Data from the Consortium on Vulnerability to Externalising Disorders and Addictions (cVEDA) in India was used (n = 9010). ACEs were evaluated using the World Health Organisation (WHO) Adverse Childhood Experiences International Questionnaire whilst substance misuse was assessed using the WHO Alcohol, Smoking and Substance Involvement Screening Test. A random-effects, two-stage individual patient data meta-analysis explained the associations between ACEs and substance misuse with adjustments for confounders such as sex and family structure.

RESULTS

1 in 2 participants reported child maltreatment ACEs and family level ACEs. Except for sexual abuse, males report more of every individual childhood adversity and are more likely to report misusing substances compared with females (87.3% vs. 12.7%). In adolescents, family level ACEs (adj OR 4.2, 95% CI 1.5-11.7) and collective level ACEs (adj OR 6.6, 95% CI 1.4-31.1) show associations with substance misuse whilst in young adults, child level ACEs such as maltreatment show similar strong associations (adj OR 2.0, 95% CI 1.1-3.5).

CONCLUSION

ACEs such as abuse and domestic violence are strongly associated with substance misuse, most commonly tobacco, in adolescent and young adult males in India. The results suggest enhancing current ACE resilience programmes and 'trauma-informed' approaches to tackling longer-term impact of ACEs in India.

FUNDING

Newton Bhabha Grant jointly funded by the Medical Research Council, UK (MR/N000390/1) and the Indian Council of Medical Research (ICMR/MRC-UK/3/M/2015-NCD-I).

Ethnic minority women’s interactions with antenatal care providers in Europe

Background

Ethnic minority women are at greater risk of maternal morbidity and mortality. Antenatal care reduces risks of adverse maternal and neonatal outcomes and supports a positive transition to motherhood. Important components of quality antenatal care are interactions between women and care providers which are supportive and empowering.

Methods

We conducted a systematic review to identify and synthesise qualitative evidence on ethnic minority women's experiences of accessing antenatal care in European countries. Following a comprehensive search of 8 databases and two-step screening process, we included 27 studies from various European countries. Study findings were coded and synthesised using a ‘best-fit' framework approach.

Findings

Overall women expressed satisfaction with their antenatal care, frequently framed in relation to experiences of maternity care in countries of origin. Women highly valued interactions with antenatal care providers which were supportive and trust-inducing, and when there was continuity of carer to facilitate this. However, studies frequently showed a dichotomy between reported satisfaction with antenatal care and experiences of interactions with care providers which could be discriminatory, stigmatising and disempowering. Some women blamed themselves for negative interactions. Language barriers were frequently identified by women as a factor which hindered their communication with antenatal care providers and the subsequent quality of care received, when suitable interpreters were not available. Negative interactions with antenatal care providers could result in a withdrawal from ongoing antenatal care for some women.

Conclusions

This review highlights the importance of quality interactions between ethnic minority women and antenatal care providers. Policy implications: Antenatal care should be provided in such a way as to facilitate trust, support and effective communication between women and care providers.

Key messages

Positive interactions with care providers form an important element of quality antenatal care for ethnic minority women in Europe. Trust, support and the provision of suitable interpreters, where needed, contribute to positive interactions with antenatal care providers for ethnic minority women in Europe.

Hemodynamic effects of left atrial appendage occlusion

BACKGROUND

Percutaneous left atrial appendage occlusion (LAAO) devices have emerged as alternatives to anticoagulation for embolic stroke prevention in patients with non-valvular atrial fibrillation (NVAF). The left atrial appendage is known to produce vasoactive neuroendocrine hormones involved in cardiovascular homeostasis. The hemodynamic impact of LAA occlusion on cardiac function remains poorly characterized.

METHODS

This is a single-center, retrospective study of sixty-seven consecutive patients who received LAAO utilizing the WATCHMAN device from May 2017 to June 2019. All patients received a comprehensive 2D transthoracic echocardiogram (TTE) prior to the procedure and a post-procedural TTE. 2D echocardiographic pre-/post-procedural measurements including left ventricular ejection fraction, tricuspid regurgitation, estimated pulmonary artery pressure, diastolic parameters, and left atrial and right ventricular strain were statistically analyzed using the paired t-test.

RESULTS

Seventy percent of study patients were male with an overall mean age of 73.0 ± 9.0 years. Analysis of post-procedural LAAO revealed statistically significant improvement in left ventricular ejection fraction (52.4 ± 12.6 vs. 56.7 ± 12.7, p < 0.001), an increase in mitral E/e' (14.1 ± 6.5 vs. 18.3 ± 10.8, p < 0.001), and a decrease right ventricular global longitudinal strain (RVGLS) (- 17.5 ± 4.6 vs. - 19.6 ± 5.7, p = 0.027) as compared to pre-procedural TTE. Peak left atrial longitudinal strain (PALS) improved post-LAAO (20.6 ± 12.2 to 22.9 ± 12.9, p = 0.040) with adjustment for cardiac arrhythmias. Post-LAAO, heart failure hospitalizations occurred in 23.9% of patients.

CONCLUSIONS

Percutaneous LAAO results in real-time atrial and ventricular hemodynamic changes as assessed by echocardiographic evaluation of LV filling pressures (E/e'), PALS, RVGLS, and LVEF.

Hospital readmissions after catheter ablation for atrial fibrillation among patients with heart failure in the United States

Background

Catheter ablation for atrial fibrillation may improve quality of life and long-term mortality among patients with heart failure.

Purpose

The rates of hospital readmission after catheter ablation for atrial fibrillation among patients with an established diagnosis of heart failure are largely unknown. We aimed to assess the rates and causes of 30-day readmission among patients with heart failure undergoing catheter ablation vs. medical therapy for atrial fibrillation in the United States.

Methods

The 2016 Nationwide Readmissions Database was screened for patients with diagnosis of heart failure and atrial fibrillation using the 10th Revision of International Classification of Diseases codes. Patients undergoing catheter ablation for atrial fibrillation were grouped separately from those treated medically for atrial fibrillation. Thirty-day readmissions were assessed for both groups.

Results

The analytical cohort included 749,776 (national estimate of 1,421,673) patients with heart failure and atrial fibrillation. This included 2,204 patients that underwent catheter ablation. Patients treated with catheter ablation had lower 30-day readmissions compared to the medical therapy group (16.8% vs 20.1%, p&lt;0.001). Fifty-five percent of all readmissions among the catheter ablation cohort were related to cardiac events. Heart failure exacerbation (40%) and arrhythmia (36%) were the most common cardiac causes for readmission after catheter ablation (Figure).

Conclusions

In a contemporary nationwide analysis of patients with heart failure and atrial fibrillation, compared to medical therapy those treated with catheter ablation for atrial fibrillation had fewer 30-day readmissions after index hospital discharge. The most common cause for readmission among patients treated with catheter ablation was heart failure exacerbation and arrhythmia.

Causes of readmission

Funding Acknowledgement

Type of funding source: None

Implications of pacemaker implantation after TAVR: insights from the Nationwide Readmissions Database

Introduction

Conduction disturbances after transcatheter aortic valve replacement (TAVR) requiring permanent pacemaker (PPM) implantation are a well-known procedural complication. Data on the effect of post-TAVR PPM implantation on 30-day readmissions is scarce.

Methods

The Nationwide Readmissions Database (NRD) is a nationally representative sample of all US hospitalizations, representing over 35 million discharges. The 2016 NRD was used to identify patients who underwent TAVR and PPM implantation from January to November 2016. Propensity matching was used to balance baseline clinical characteristics.

Results

Of the 44,607 patients who underwent TAVR, 4,878 (10.9%) required permanent pacemaker implantation during their index hospitalization. Patients requiring PPM during their index admission for TAVR had a higher crude median length of stay (LOS) (5d vs. 3d, p&lt;0.001), median cost of index admission ($61,604 vs. $45,513, p&lt;0.001) and rate of 30-day readmission (14.5% vs 11.2%, p&lt;0.001). After 2:1 propensity matching, PPM patients still had a higher median LOS (5d vs. 3d, p&lt;0.001), median cost of index admission ($61,902 vs. $41,162, p&lt;0.001), and rate of 30-day readmission (13.8% vs 11.1%, p=0.003). Patients who received PPM were more likely to be older (81.1 vs 80.3, OR 1.01, CI 1.01–1.02), diabetic (OR 1.27, 1.13–1.44), obese (OR 1.22, 1.05–1.43), and have right (OR 4.35, 3.72–5.09) or left (OR 1.80, 1.51–2.15) bundle branch blocks on multivariate analysis. Causes of readmission in patients with and without PPM were predominantly non-cardiac (62.9% vs 68.0%). Heart failure was the most common cause of readmission for both groups (18.4% vs 14.6%). Median cost of readmissions ($8716 vs $8250, p=0.34) and LOS (4d vs 4d, p=1) were not significantly different during readmissions.

Conclusions

Based on a nationally representative sample, 10.9% of patients undergoing TAVR required PPM implantation during the index hospitalization. Age, diabetes, obesity, and right or left bundle branch blocks were significant predictors of PPM implantation. PPM implantation resulted in significantly higher LOS, costs, and 30-day readmissions on propensity-matched analysis.

Funding Acknowledgement

Type of funding source: None

Sudden death in a patient with long QT syndrome presenting with an epileptic phenotype

Patients with epilepsy suffer from a higher mortality rate than the general population, a portion of which is not due to epilepsy itself or comorbid conditions. Sudden unexpected death in epilepsy (SUDEP) is a common but poorly understood cause of death in patients with intractable epilepsy and often afflicts younger patients. The pathophysiology of SUDEP is poorly defined but does not appear to be related to prolonged seizure activity or resultant injury. Interestingly, a subset of patients with confirmed long QT syndrome (LQTS) present with a seizure phenotype and may have concurrent epilepsy. In this case, we present a patient who initially presented with a seizure phenotype. Further workup captured PMVT on an outpatient event monitor, and the patient was subsequently diagnosed with LQTS1. A substantial number of patients with LQTS initially present with a seizure phenotype. These patients may represent a subset of SUDEP cases resulting from ventricular arrhythmias. Appropriate suspicion for ventricular arrhythmias is necessary for proper arrhythmia evaluation and management in patients presenting with epilepsy.

Plugging the Hole: Diagnosis and Management of Post-Myocardial Infarction Ventricular Septal Defect

•

VSD after MI is a rare and often fatal complication.

•

Echocardiography is essential in the diagnosis and management of these patients.

•

Though urgent surgical repair is recommended, operative risk is often high.

•

VA ECMO and percutaneous closure under echocardiographic guidance are alternatives.

•

Echocardiography can identify persistent AV closure and stasis in the aortic root.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Aortic Valve Calcification as a Predictor of Post-Transcatheter Aortic Valve Replacement Pacemaker Dependence

Background

Atrioventricular block requiring permanent pacemaker (PPM) implantation is a common complication of transcatheter aortic valve replacement (TAVR). The mechanism of atrioventricular (AV) block during TAVR is not fully understood, but it may be due to the mechanical stress of TAVR deployment, resulting in possible injury to the nearby compact AV node. Aortic valve calcification (AVC) may worsen this condition and has been associated with an increased risk for post-TAVR PPM implantation. We performed a retrospective analysis to determine if AVC is predictive for long-term right ventricular (RV) pacing in post-TAVR pacemaker patients at 30 days.

Methods

A total of 262 consecutive patients who underwent TAVR with a balloon-expandable valve were analyzed. AVC data were derived from contrast-enhanced computed tomography and characterized by leaflet sector and region.

Results

A total of 25 patients (11.1%) required post-TAVR PPM implantation. Seventeen patients did not require RV pacing at 30 days. Nine of these 17 patients had no RV pacing requirement within 10 days. The presence of intra-procedural heart block (P = 0.004) was the only significant difference between patients who did not require PPM and those who required PPM but they were not RV pacing-dependent at 30 days. Non-coronary cusp (NCC) calcium volume was significantly higher in patients who were pacemaker-dependent at 30 days (P = 0.01) and a calcium volume of > 239.2 mm³ in the NCC was strongly predictive of pacemaker dependence at 30 days (area under the curve (AUC) = 0.813). Pre-existing right bundle branch block (RBBB) (odds ratio (OR) 105.4, P = 0.004), bifascicular block (OR 12.5, P = 0.02), QRS duration (OR 70.43, P = 0.007) and intra-procedural complete heart block (OR 12.83, P = 0.03) were also predictive of pacemaker dependence at 30 days.

Conclusions

In patients who required PPM after TAVR, quantification of AVC by non-coronary leaflet calcium volume was found to be a novel predictor for RV pacing dependence at 30 days. The association of NCC calcification and PPM dependence may be related to the proximity of the conduction bundle to the non-coronary leaflet. Further studies are necessary to improve risk prediction for long-term RV pacing requirements following TAVR.

Impact of Slice Thickness on the Predictive Value of Lung Cancer Screening Computed Tomography in the Evaluation of Coronary Artery Calcification

Background

Image reconstruction thickness may impact quantitative coronary artery calcium scoring (CACS) from lung cancer screening computed tomography (LCSCT), limiting its application in practice.

Methods and Results

We evaluated Agatston‐based quantitative CACS from 1.25‐mm LCSCT and cardiac computed tomography for agreement in 87 patients. We then evaluated Agatston‐based quantitative CACS from 1.25‐, 2.5‐, and 5.0‐mm slice thickness LCSCT for agreement in 258 patients. Secondary analysis included the impact of slice thickness on predictive value of 4‐year outcomes. Median age of patients who underwent 1.25‐mm LCSCT and cardiac computed tomography was 63 years (interquartile interval, 57, 68). CACS from 1.25‐mm LCSCT and cardiac computed tomography demonstrated a strong Pearson correlation, R=0.9770 (0.965, 0.985), with good agreement. The receiver operating characteristic curve areas under the curve for cardiac computed tomography and LCSCT were comparable at 0.8364 (0.6628, 1.01) and 0.8208 (0.6431, 0.9985), respectively (P=0.733). Median age of patients who underwent LCSCT with 3 slice thicknesses was 66 years (interquartile interval, 63, 73). Compared with CACS from 1.25‐mm scans, CACS from 2.5‐ and 5.0‐mm scans demonstrated strong Pearson correlations, R=0.9949 (0.9935, 0.996) and R=0.9478 (0.9338, 0.959), respectively, though bias was largely negative for 5.0‐mm scans. Receiver operating characteristic curve areas under the curve for 1.25‐, 2.5‐, and 5.0‐mm scans were comparable at 0.7040 (0.6307, 0.7772), 0.7063 (0.6327, 0.7799), and 0.7194 (0.6407, 0.7887), respectively (P=0.6487). When using individualized high‐risk thresholds derived from respective receiver operating characteristic curves, all slice thicknesses demonstrated similar prognostic value.

Conclusions

Slice thickness is an important consideration when interpreting Agatston CACS from LCSCTs. Despite the absence of ECG gating, it appears reasonable to report CACS from either 1.25‐ or 2.5‐mm slice thickness LCSCT to help stratify cardiovascular risk. Conversely, 5.0‐mm scans largely underidentify calcium, limiting practical use within the established CACS values used to categorize cardiovascular risk.

Congenital intestinal malrotation presenting in octogenarians: a report of two cases

Malrotation is part of a spectrum of small and large bowel positional and fixational abnormalities caused by the failure of the fetal intestine to complete a 270-degree rotation around the superior mesenteric artery axis. Rarely, it presents in the adult as a cause of acute small bowel obstruction. Chronic symptoms of malrotation in adults are subtle, and include intermittent abdominal pain, nausea and vomiting. We present two cases of malrotation in octogenarian men presenting acutely with small bowel obstruction. Both patients were treated with emergency surgery. In one case the chronic symptoms resolved postoperatively. Malrotation and midgut volvulus should be considered as a rare differential diagnosis for small bowel obstruction in adults. Suspicions should be increased when there is a history of recurrent presentations with similar symptoms.

Small bowel obstruction secondary to diaphragmatic herniation following transabdominal cardiac ablation

We report an unusual case of strangulated diaphragmatic hernia secondary to a pericardial ablation, which resulted in necrosis of the incarcerated small bowel. Through a literature search, we have found a limited number of similar cases introducing a case series for this rare but potentially fatal condition.

P6572Sinus arrest post-cardioversion

Introduction

Sinus arrest remains a recognized but likely underreported complication of cardioversion, with incidence ranging widely in the literature, from virtually 0% to 1.5%. After a case of elective cardioversion resulting in the need for ECMO support, we investigated possible risk factors that could help predict adverse outcomes after cardioversion.

Hypothesis

Cardioversion, while generally benign, is not without risks, and further study may help elucidate predictors of morbidity and mortality.

Methods

We retrospectively reviewed data of all patients who underwent cardioversion at three hospitals within the Lifespan health system, Rhode Island Hospital, Newport Hospital, and the Miriam Hospital, between 2000 and 2015. 23 patients who experienced sinus arrest after cardioversion, and characteristics of these patients were compared with those of 3:1 age-and-gender matched controls using binomial logistic regression analysis on Stata.

Results

Of 12,156 patients who underwent cardioversion, 23 patients (57% male, mean age 78±14), or 0.18%, experienced immediate post-cardioversion sinus arrest, defined as absence of sinus activity for greater than five seconds. Compared with 3:1 age-and-gender-matched controls who underwent cardioversion without incident, binomial logistic regression revealed that paroxysmal atrial fibrillation (OR 11.8; 95% CI 1.85–75.72; p=0.009), beta-blocker use (OR 58.0; 95% CI 2.4–1404.48; p=0.013), Amiodarone use (OR 19.9; 95% CI 2.0–198.32; p=0.011), and elevated ventricular rate (CV 0.028; 95% CI 0.0031–0.053; p=0.027) were statistically significant predictors of sinus arrest after cardioversion. Calcium-channel blocker use, Digoxin use, age, gender, PR interval, QRS duration, and corrected QT interval were not significant associations.

Conclusions

Sparse data exists regarding characteristics predisposing patients to adverse outcomes following cardioversion, and further risk stratification is warranted, given the potential for significant morbidity and mortality. Our findings raise questions that demand elucidation, such as whether beta-blockers or Amiodarone should be held prior to cardioversion.

PVCs, PVC-Induced Cardiomyopathy, and the Role of Catheter Ablation

Premature ventricular contractions (PVCs) are common arrhythmias noticed in the clinical setting because of premature depolarization of the ventricular myocytes. Although often thought to be reflective of underlying disease rather than intrinsically harmful, PVCs have recently been linked with worse outcomes in patients without significant cardiac disease. Long-term exposure to a high PVC burden can lead to the development of PVC-induced cardiomyopathy. The pathogenesis of this condition is poorly understood at the current time. Many studies have suggested that catheter ablation of these PVCs may result in reversal of the PVC-induced cardiomyopathy. This article will go over the natural history of PVCs and PVC-induced cardiomyopathy, as well as review the current literature on the role of catheter ablation in treating PVC-induced cardiomyopathy.

Relative predictive value of lung cancer screening CT versus myocardial perfusion attenuation correction CT in the evaluation of coronary calcium

Coronary artery calcium scores (CACS) from lung cancer screening computed tomography (LCSCT) or myocardial perfusion attenuation correction computed tomography (ACCT) are not routinely performed or reported. CACS from LCSCT and ACCT have not been directly compared in the same patient population. We identified 66 patients who underwent both LCSCT (non-gated) and ECG-gated cardiac CT (CCT) within a 2-year span. Of this population, 40 subjects had also undergone ACCT. Using the Agatston method, CACS for 264 individual vessels from the LCSCT population and for 160 vessels from ACCT population were calculated and evaluated for agreement with ECG-gated CCT as the gold standard. Secondary analysis included a comparison of individual vessel contribution to variations in agreement and a comparison of total CACS from CCT, LCSCT, and ACCT for respective MACE prediction. CACS from LCSCT demonstrated a strong Pearson correlation, r = 0.9017 (0.876–0.9223), with good agreement when compared to CACS from CCT. CACS from ACCT demonstrated a significantly (P < 0.00001) weaker correlation, r = 0.5593 (0.4401–0.6592). On an individual vessel basis, CACS from all major vessels (LM, LAD, LCX, and RCA) contributed to the weaker correlation. For total vessel CACS, LCSCT demonstrated comparable area under the curve (AUC) for the receiver operating characteristic (ROC) curve (LCSCT AUC = 0.8133 and CCT AUC = 0.8302, P = 0.691) for prediction of MACE. Although ACCT demonstrated a similar AUC (ACCT AUC = 0.7969, P = 0.662) for MACE prediction the cutoff value for elevated risk was extremely low. In conclusion, LCSCT outperformed ACCT at calcium scoring by providing better agreement and comparable risk assessment to CCT despite the absence of ECG-gating. It is therefore reasonable to use LCSCT images to derive and report Agatston-based CACS for cardiovascular risk assessment, whereas the use of ACCT images to report Agatston-based CACS is not currently practical.

Engineered Protein Polymer-Gold Nanoparticle Hybrid Materials for Small Molecule Delivery

We have fabricated protein polymer-gold nanoparticle (P-GNP) nanocomposites that exhibit enhanced binding and delivery properties of the small hydrophobic molecule drug, curcumin, to the model breast cancer cell line, MCF-7. These hybrid biomaterials are constructed via in situ GNP templated-synthesis with genetically engineered histidine tags. The P-GNP nanocomposites exhibit enhanced small molecule loading, sustained release and increased uptake by MCF-7 cells. When compared to the proteins polymers alone, the P-GNPs demonstrate a greater than 7-fold increase in curcumin binding, a nearly 50% slower release profile and more than 2-fold increase in cellular uptake of curcumin. These results suggest that P-GNP nanocomposites serve as promising candidates for drug delivery vehicles.

Indigenous rangeland resource management in the mountainous areas of northern Nepal: a case study from the Rasuwa District

Rangelands perform numerous functions that have significant ecological and livelihood values for mountain societies in Nepal. There are no other systems more suitable than indigenous management systems, which have evolved over long periods of time and offer approaches to land use that are suitable to the varying climatic, biophysical conditions and ethnic diversity that characterise Nepal. However, traditional resource management practices have been ignored in the past, which has resulted in conflicts and resource degradation. In this context, a survey was conducted in the Rasuwa District of northern Nepal to identify existing indigenous rangeland management systems, examine the challenges facing the development of sustainable practices and suggest possible strategies for promoting their development. It was concluded from this study that local herders in the Rasuwa District of northern Nepal have developed effective indigenous rangeland management systems that include good grazing and conservation practices. Well organised local institutional arrangements and efficient traditional right and tenure systems have evolved that result in the sustainable use of rangeland resources. However, both internal and external factors are now challenging these traditional systems. Results indicated that to remain sustainable rangeland management systems in northern Nepal will require a clear recognition of indigenous knowledge of rangeland management as well as the integration of indigenous practices and strategies with modern technologies. More attention should be paid to the facilitation of rangeland legislation covering traditional rights and customary tenure, institutional cooperation and collaboration between government and civil society. Co-management and participatory research and development should be initiated on rangeland resources and the improvement of infrastructure and public service systems.