Predictors of Seatbelt Use Among Saudi Adults: Results From the National Biobank Project

Introduction: Road traffic crashes (RTCs) are a leading cause of death and disabilities and impose a significant burden on the healthcare system and economy of Saudi Arabia. Around 20% of all hospital beds are occupied by victims of RTCs, which represent approximately 80% of trauma deaths occurring in these facilities. Using a seatbelt is an effective method to reduce traffic deaths and minimize the extent of associated injuries. However, little is currently known about the prevalence and predictors of seatbelt use in Saudi Arabia. More studies are needed to determine the trends of seatbelt use and study the relationship between individual factors and compliance with seatbelt use laws. The aim of the present study is to examine the prevalence and predictors of seatbelt use using the National Saudi Biobank dataset.

Materials and Methods: This cross-sectional study was conducted using an in-person survey from the Saudi National Biobank (SNB). The participants were adults affiliated with the Ministry of National Guard Health Affairs in Riyadh who were examined between 2017 and 2019. Chi-squared and Wald tests were used to assess the association between the respondents' characteristics and their seatbelt use. In addition, logistic regression models were constructed to assess the univariate and multivariate associations between seatbelt use and potential predictors. All statistical tests were two-sided, and the findings were considered significant at P < 0.05.

Results: A total of 5,790 adults participated in the survey. The majority of the participants (52.44%) were between 18 and 25 years old, half were males, and 58.80% were single. About 42.83% of the participants reported consistent seatbelt use as drivers or passengers. In the multivariable analysis, females were 86% less likely to wear seatbelts than males (OR = 0.136, 95%CI = 0.107–0.173). Individuals who rated their mental health as “weak” were 26% less likely to wear seatbelts than those who reported “excellent” mental health status.

Conclusion: Seatbelt use remains low in the country and substantially lower than in developed countries. Young adults, females, and individuals reporting suboptimal mental health were less likely to fasten their seatbelts. These findings are valuable for public health programs to target specific groups and raise awareness about the need to increase seatbelt compliance and reduce traffic injuries.

Bonding performance of dispersed filler resin composite CAD/CAM blocks with different surface treatment protocols

The effect of various pretreatments on the bonding of a resin cement to resin-composite CAD/CAM blocks (RCBs) was examined. The surface of dispersed-filler RCBs (DF-RCBs) and a polymer infiltrated ceramic network RCB (PICN-RCB) was roughened using hydrofluoric acid etching (HF) or sandblasting, and followed by silanization and/or universal adhesive (UA) application. Microtensile bond strength (µTBS), surface roughness parameters (arithmetical mean height (Sa); developed interfacial area ratio (Sdr)), and critical surface energy (γ_c) were determined. For most DF-RCBs, the highest µTBS was obtained using HF+UA. UA application to DF-RCBs resulted in similar or higher µTBS compared to silanization, which indicates that silane treatment is not crucial for DF-RCBs, especially after HF. In contrast, the highest µTBS to PICN-RCB was obtained with silanization. Both roughening pretreatments significantly increased the surface roughness parameters and the γ_c of all RCBs. The γ_c was positively correlated with Sa (r=0.756, p<0.001) and Sdr (r=0.837, p<0.001).

Clinical Teaching: Sixty Tips for Successful Implementation

A good preparation of clinical teaching which is followed by systematic implementation will result in better training outcomes. In this short descriptive paper, we provide 60 tips to everyone who conducts clinical supervision or teaching to medical students in the ward. These tips highlight the roles and characteristics of (1) clinical tutors, (2) students, (3) clinical teaching environment and (4) patients. They serve as a mini guide.

Sex Differences in Instantaneous Wave-Free Ratio or Fractional Flow Reserve-Guided Revascularization Strategy

OBJECTIVES

This study sought to evaluate sex differences in procedural characteristics and clinical outcomes of instantaneous wave-free ratio (iFR)- and fractional flow reserve (FFR)-guided revascularization strategies.

BACKGROUND

An iFR-guided strategy has shown a lower revascularization rate than an FFR-guided strategy, without differences in clinical outcomes.

METHODS

This is a post hoc analysis of the DEFINE-FLAIR (Functional Lesion Assessment of Intermediate stenosis to guide Revascularization) study, in which 601 women and 1,891 men were randomized to iFR- or FFR-guided strategy. The primary endpoint was 1-year major adverse cardiac events (MACE), a composite of all-cause death, nonfatal myocardial infarction, or unplanned revascularization.

RESULTS

Among the entire population, women had a lower number of functionally significant lesions per patient (0.31 ± 0.51 vs. 0.43 ± 0.59; p < 0.001) and less frequently underwent revascularization than men (42.1% vs. 53.1%; p < 0.001). There was no difference in mean iFR value according to sex (0.91 ± 0.09 vs. 0.91 ± 0.10; p = 0.442). However, the mean FFR value was lower in men than in women (0.83 ± 0.09 vs. 0.85 ± 0.10; p = 0.001). In men, an FFR-guided strategy was associated with a higher rate of revascularization than an iFR-guided strategy (57.1% vs. 49.3%; p = 0.001), but this difference was not observed in women (41.4% vs. 42.6%; p = 0.757). There was no difference in MACE rates between iFR- and FFR-guided strategies in both women (5.4% vs. 5.6%, adjusted hazard ratio: 1.10; 95% confidence interval: 0.50 to 2.43; p = 0.805) and men (6.6% vs. 7.0%, adjusted hazard ratio: 0.98; 95% confidence interval: 0.66 to 1.46; p = 0.919).

CONCLUSIONS

An FFR-guided strategy was associated with a higher rate of revascularization than iFR-guided strategy in men, but not in women. However, iFR- and FFR-guided strategies showed comparable clinical outcomes, regardless of sex. (Functional Lesion Assessment of Intermediate Stenosis to guide Revascularization [DEFINE-FLAIR]; NCT02053038).

The prevalence of head and facial injuries among children in Saudi Arabia following road traffic crashes

BACKGROUND

Motor vehicle crashes (MVCs) are the leading cause of death among children in Saudi Arabia. Childhood injuries can be prevented or minimized if safety measures, such as car seats, are implemented. The literature on the epidemiology of head and facial injury among children is limited, which affects the ability to understand the extent of the burden and hinders investment in public health prevention.

OBJECTIVE

Describe the epidemiology of head and facial injuries among children admitted to the hospital following MVCs.

DESIGN

Retrospective chart review.

SETTING

Five hospitals in several regions.

PATIENTS AND METHODS

We collected data on all patients ≤16 years old, who were admitted to the hospital following MVCs between 2016-2019. Differences in various characteristics like head injury status and age groups were compared.

MAIN OUTCOME MEASURES

Head and facial injuries.

SAMPLE SIZE

253 patients.

RESULTS

Of the injured population, 97 (38.3%) sustained a head injury, and 88 (34.8%) had a facial injury. Thirteen (9.1%) children were driving the car at the time of the crash. About half of the children were seated in the back (53.8%) without a seatbelt or safety seat.

CONCLUSION

The prevalence of head and facial injuries is striking. In addition, the study revealed that driving among children is not uncommon, which warrants monitoring and implementing interventions. Improved documentation of restraint use and police enforcement of safety laws can play a significant role in reducing associated injuries. The study findings highlight the importance of combination or rear seating as well as age-appropriate restraint in order to reduce the likelihood of head or facial injuries among children.

LIMITATIONS

Retrospective study using the electronic search system to identify patients, but may have missed cases that were not coded correctly. Large amount of missing data for some variables. Additionally, the analysis was limited to those admitted to the hospital.

CONFLICT OF INTEREST

None.

Comparison of Major Adverse Cardiac Events Between Instantaneous Wave-Free Ratio and Fractional Flow Reserve-Guided Strategy in Patients With or Without Type 2 Diabetes: A Secondary Analysis of a Randomized Clinical Trial

Importance

Invasive physiologic indices such as fractional flow reserve (FFR) and instantaneous wave-free ratio (iFR) are used in clinical practice. Nevertheless, comparative prognostic outcomes of iFR-guided and FFR-guided treatment in patients with type 2 diabetes have not yet been fully investigated.

Objective

To compare 1-year clinical outcomes of iFR-guided or FFR-guided treatment in patients with and without diabetes in the Functional Lesion Assessment of Intermediate Stenosis to Guide Revascularization (DEFINE-FLAIR) trial.

Design, Setting, and Participants

The DEFINE-FLAIR trial is a multicenter, international, randomized, double-blinded trial that randomly assigned 2492 patients in a 1:1 ratio to undergo either iFR-guided or FFR-guided coronary revascularization. Patients were eligible for trial inclusion if they had intermediate coronary artery disease (40%-70% diameter stenosis) in at least 1 native coronary artery. Data were analyzed between January 2014 and December 2015.

Interventions

According to the study protocol, iFR of 0.89 or less and FFR of 0.80 or less were used as criteria for revascularization. When iFR or FFR was higher than the prespecified threshold, revascularization was deferred.

Main Outcomes and Measures

The primary end point was major adverse cardiac events (MACE), defined as the composite of all-cause death, nonfatal myocardial infarction, or unplanned revascularization at 1 year. The incidence of MACE was compared according to the presence of diabetes in iFR-guided and FFR-guided groups.

Results

Among the total trial population (2492 patients), 758 patients (30.4%) had diabetes. Mean age of the patients was 66 years, 76% were men (1868 of 2465), and 80% of patients presented with stable angina (1983 of 2465). In the nondiabetes population (68.5%; 1707 patients), iFR guidance was associated with a significantly higher rate of deferral of revascularization than the FFR-guided group (56.5% [n = 477 of 844] vs 46.6% [n = 402 of 863]; P < .001). However, it was not different between the 2 groups in the diabetes population (42.1% [n = 161 of 382] vs 47.1% [n = 177 of 376]; P = .15). At 1 year, the diabetes population showed a significantly higher rate of MACE than the nondiabetes population (8.6% vs 5.6%; adjusted hazard ratio [HR], 1.88; 95% CI, 1.28-2.64; P < .001). However, there was no significant difference in MACE rates between iFR-guided and FFR-guided groups in both the diabetes (10.0% vs 7.2%; adjusted HR, 1.33; 95% CI, 0.78-2.25; P = .30) and nondiabetes population (4.7% vs 6.4%; HR, 0.83; 95% CI, 0.51-1.35; P = .45) (interaction P = .25).

Conclusions and Relevance

The diabetes population showed significantly higher risk of MACE than the nondiabetes population, even with the iFR-guided or FFR-guided treatment. The iFR-guided and FFR-guided treatment showed comparable risk of MACE and provided equal safety in selecting revascularization target among patients with diabetes.

Trial Registration

ClinicalTrials.gov identifier: NCT02053038.

A268 PREOPERATIVE EUS-GUIDED FNA IS ASSOCIATED WITH BETTER OVERALL SURVIVAL IN RESECTABLE PANCREATIC CANCER WHEN COMPARED TO UPFRONT SURGERY WITHOUT PREOPERATIVE TISSUE ACQUISITION: A SYSTEMIC REVIEW AND META-ANALYSIS

Background

Endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) is the standard of care in advanced pancreatic cancer. In resectable disease, preoperative EUS-FNA can help to identify benign etiology and other cancers while preventing unnecessary surgery. However, concerns regarding tumor seeding and pancreatitis have led some experts to advocate for upfront surgery without tissue sampling.

Aims

To conduct a systematic review and meta-analysis of the risks and benefits of performing pre-operative EUS-FNA in patients with suspected, resectable pancreatic cancer.

Methods

A literature search was performed up to April 2019 using MEDLINE, EMBASE, and ISI Web of Knowledge databases with terms specified for pancreatic neoplasm and FNA. All fully published adult studies that compared preoperative EUS-FNA to EUS without FNA in resectable pancreatic cancer for short- and long-term outcomes were included. Results were reported as Odds ratios (OR) or weighted mean differences (WMD) with 95% confidence intervals (CI) using a random effects model. Heterogeneity, publication bias and quality of studies were evaluated. Sensitivity analyses were performed. The primary outcome is overall survival. Secondary outcomes include cancer free survival, tumor recurrence and seeding, and post FNA adverse events.

Results

An initial search yielded 2814 citations. Six retrospective studies were included with 1155 patients in the EUS-FNA group vs 2067 patients in the comparator group. Overall survival was reported in three studies (n=2701: 796 EUS-FNA, 1905 non-FNA). Patients with preoperative EUS-FNA had better overall survival compared to the non-FNA group (WMD, 4.40 months [0.02 to 8.78]). In adenocarcinoma patients (2 studies, n=2050), there was no significant difference in overall survival (WMD, 2.94 months [-3.87 to 9.74]). Cancer-free survival did not differ significantly between the two groups (WMD, 2.08 months [-2.22 to 6.38]). Moreover, EUS with FNA was not associated with increased rates of tumor recurrence (OR, 0.55 [0.30–1.02]) or peritoneal carcinomatosis (OR, 0.81 [0.56–1.18]). Post-FNA pancreatitis was rare (1.7%), with all patients treated conservatively. Sensitivity analyses yielded similar findings across the different outcomes tested.

Conclusions

In this meta-analysis, preoperative EUS-FNA in resectable pancreatic cancer was associated with significantly greater overall survival when compared to the non-FNA group with no significant difference in rate of tumour recurrence and/or peritoneal seeding. These findings are limited by the retrospective nature of the included studies; randomized controlled trials are needed to confirm these results.

Funding Agencies

None

Enhanced electrochemical performance of α-MoO3/graphene nanocomposites prepared by an in situ microwave irradiation technique for energy storage applications

Nanoparticles of α-molybdenum oxide (α-MoO₃) are directly grown on graphene sheets using a surfactant-free facile one step ultrafast in situ microwave irradiation method.

Safety of the Deferral of Coronary Revascularization on the Basis of Instantaneous Wave-Free Ratio and Fractional Flow Reserve Measurements in Stable Coronary Artery Disease and Acute Coronary Syndromes

OBJECTIVES

The aim of this study was to investigate the clinical outcomes of patients deferred from coronary revascularization on the basis of instantaneous wave-free ratio (iFR) or fractional flow reserve (FFR) measurements in stable angina pectoris (SAP) and acute coronary syndromes (ACS).

BACKGROUND

Assessment of coronary stenosis severity with pressure guidewires is recommended to determine the need for myocardial revascularization.

METHODS

The safety of deferral of coronary revascularization in the pooled per-protocol population (n = 4,486) of the DEFINE-FLAIR (Functional Lesion Assessment of Intermediate Stenosis to Guide Revascularisation) and iFR-SWEDEHEART (Instantaneous Wave-Free Ratio Versus Fractional Flow Reserve in Patients With Stable Angina Pectoris or Acute Coronary Syndrome) randomized clinical trials was investigated. Patients were stratified according to revascularization decision making on the basis of iFR or FFR and to clinical presentation (SAP or ACS). The primary endpoint was major adverse cardiac events (MACE), defined as the composite of all-cause death, nonfatal myocardial infarction, or unplanned revascularization at 1 year.

RESULTS

Coronary revascularization was deferred in 2,130 patients. Deferral was performed in 1,117 patients (50%) in the iFR group and 1,013 patients (45%) in the FFR group (p < 0.01). At 1 year, the MACE rate in the deferred population was similar between the iFR and FFR groups (4.12% vs. 4.05%; fully adjusted hazard ratio: 1.13; 95% confidence interval: 0.72 to 1.79; p = 0.60). A clinical presentation with ACS was associated with a higher MACE rate compared with SAP in deferred patients (5.91% vs. 3.64% in ACS and SAP, respectively; fully adjusted hazard ratio: 0.61 in favor of SAP; 95% confidence interval: 0.38 to 0.99; p = 0.04).

CONCLUSIONS

Overall, deferral of revascularization is equally safe with both iFR and FFR, with a low MACE rate of about 4%. Lesions were more frequently deferred when iFR was used to assess physiological significance. In deferred patients presenting with ACS, the event rate was significantly increased compared with SAP at 1 year.

Clinical predictors of progression and clearance of low-level CMV DNAemia in solid organ transplant recipients

BACKGROUND

Low-level CMV DNAemia is common and in the absence of treatment may either progress to higher viral loads that require therapy, or may spontaneously resolve. The clinical predictors of progression and spontaneous viral clearance are not well defined.

METHODS

We performed a retrospective cohort study of organ transplant recipients who had untreated low-level CMV DNAemia (<1000 IU/mL). Outcomes were evaluated for 8 weeks after initial viral detection, and progression to CMV high viral load was defined as CMV viral load ≥1000 IU/mL. CMV DNAemia doubling time was calculated for a subset of patients with sufficient viral load timepoints.

RESULTS

Of the 297 patients analyzed, 118/297 (39.7%) patients progressed to a high viral load and the remaining cleared DNAemia spontaneously (46.8%) or remained at low level (13.4%). In multivariate analysis, progression was significantly more likely in lung transplant recipients (odds ratio 3.09) and less likely in those with an episode of previously treated CMV infection (odds ratio 0.081). In a subset of 27 patients with progression, the doubling time for CMV DNAemia was a median of 6.1 days (range 2.4-21.8).

CONCLUSION

We found that previous CMV infection significantly decreased the likelihood of low-level DNAemia progression suggesting that CMV immunity plays a role in progression vs spontaneous clearance.

Use of Viral Load as a Surrogate Marker in Clinical Studies of Cytomegalovirus in Solid Organ Transplantation: A Systematic Review and Meta-analysis

Symptomatic cytomegalovirus (CMV) disease has been the standard endpoint for clinical trials in organ transplant recipients. Viral load may be a more relevant endpoint due to low frequency of disease. We performed a meta-analysis and systematic review of the literature. We found several lines of evidence to support the validity of viral load as an appropriate surrogate end-point, including the following: (1) viral loads in CMV disease are significantly greater than in asymptomatic viremia (odds ratio, 9.3 95% confidence interval, 4.6-19.3); (2) kinetics of viral replication are strongly associated with progression to disease; (3) pooled incidence of CMV viremia and disease is significantly lower during prophylaxis compared with the full patient follow-up period (viremia incidence: 3.2% vs 34.3%; P < .001) (disease incidence: 1.1% vs 13.0%; P < .001); (4) treatment of viremia prevented disease; and (5) viral load decline correlated with symptom resolution. Based on the analysis, we conclude that CMV load is an appropriate surrogate endpoint for CMV trials in organ transplant recipients.

Freestanding flexible, pure and composite form of reduced graphene oxide paper for ammonia vapor sensing

Metal oxides based graphene nanocomposites were used for ammonia vapour sensing. The self-assembly process was adopted to prepare freestanding flexible pure rGO, CeO₂-rGO and SnO₂-rGO composite papers. The structural studies confirmed the formation of rGO composite papers. The ammonia vapor sensing was demonstrated using an impedance analyzer at different humidity levels as well as concentration. The CeO₂-rGO composite paper achieved a sensitivity of 51.70 ± 1.2%, which was higher than that of pure rGO and SnO₂-rGO composite paper. Both the surfaces (top and bottom) of the papers are active in efficiently sensing ammonia, which makes the present work unique. The results reveal that metal oxide/rGO papers can be effectively utilized in real time sensor application.

Clinical and economic burden of infections in hospitalized solid organ transplant recipients compared with the general population in Canada - a retrospective cohort study

Infections continue to be a major cause of post-transplant morbidity and mortality, requiring increased health services utilization. Estimates on the magnitude of this impact are relatively unknown. Using national administrative databases, we compared mortality, acute care health services utilization, and costs in solid organ transplant (SOT) recipients to nontransplant patients using a retrospective cohort of hospitalizations in Canada (excluding Manitoba/Quebec) between April-2009 and March-2014, with a diagnosis of pneumonia, urinary tract infection (UTI), or sepsis. Costs were analyzed using multivariable linear regression. We examined 816 324 admissions in total: 408 352 pneumonia; 328 066 UTI's; and 128 275 sepsis. Unadjusted mean costs were greater in SOT compared to non-SOT patients with pneumonia [(C$14 923 ± C$29 147) vs. (C$11 274 ± C$18 284)] and sepsis [(C$23 434 ± C$39 685) vs. (C$20 849 ± C$36 257)]. Mortality (7.6% vs. 12.5%; P < 0.001), long-term care transfer (5.3% vs. 16.5%; P < 0.001), and mean length of stay (11.0 ± 17.7 days vs. 13.1 ± 24.9 days; P < 0.001) were lower in SOT. More SOT patients could be discharged home (63.2% vs. 44.3%; P < 0.001), but required more specialized care (23.5% vs. 16.1%; P < 0.001). Adjusting for age and comorbidities, hospitalization costs for SOT patients were 10% (95% CI: 8-12%) lower compared to non-SOT patients. Increased absolute hospitalization costs for these infections are tempered by lower adjusted costs and favorable clinical outcomes.

What Saudi teachers know about epilepsy: A cross-sectional study of Tabuk City

PURPOSE

This study was conducted to evaluate awareness, knowledge, and attitudes of teachers toward the disease in Tabuk City in north Saudi Arabia and identify areas in which training and education are required.

METHOD

Data were collected from 349 school teachers using a structured 28-item questionnaire. Data were collected between December 2017 and May 2018 in Tabuk City.

RESULTS

In general, the study shows a negative trend in knowledge and attitude toward epilepsy. The majority of the participants (84%) have read or heard about epilepsy, and more than half (67%) had witnessed a seizure. Epilepsy was considered contagious and psychological by 1.7% and 56%, respectively. Regarding attitude, 68% would not approve a son/daughter marriage to a person with epilepsy. This attitude correlates to the level of education as the percentage is higher for those who hold a Bachelor's or Master's degree, p < 0.05. Even though 84% of the participants reported knowing how to help a patient during a seizure, the majority of the participants had incorrect procedures, holding the legs and arms and believing that smelling onions is helpful to end the seizure. Moreover, almost half of the participants (46%) believed that a person with epilepsy cannot be successful in high-ranking professions. This belief was found to be more common in females than their counterparts, p < 0.05.

CONCLUSION

School teachers' knowledge about epilepsy needs improvement. A focus on educational interventions about epilepsy are needed to develop a well-informed and tolerant community.

TBX18 overexpression enhances pacemaker function in a rat subsidiary atrial pacemaker model of sick sinus syndrome

KEY POINTS

The sinoatrial node (SAN) is the primary pacemaker of the heart. SAN dysfunction, or 'sick sinus syndrome', can cause excessively slow heart rates and pauses, leading to exercise limitation and syncope, currently treated by implantation of an electronic pacemaker. 'Biopacemaking' utilises gene therapy to restore pacemaker activity by manipulating gene expression. Overexpressing the HCN pacemaker ion channel has been widely used with limited success. We utilised bradycardic rat subsidiary atrial pacemaker tissue to evaluate alternative gene targets: the Na+ /Ca2+ exchanger NCX1, and the transcription factors TBX3 and TBX18 known to be involved in SAN embryonic development. TBX18 overexpression restored normal SAN function, as assessed by increased rate, improved heart rate stability and restoration of isoprenaline response. TBX3 and NCX1 were not effective in accelerating the rate of subsidiary atrial pacemaker tissue. Gene therapy targeting TBX18 could therefore have the potential to restore pacemaker function in human sick sinus syndrome obviating electronic pacemakers.

ABSTRACT

The sinoatrial node (SAN) is the primary pacemaker of the heart. Disease of the SAN, sick sinus syndrome, causes heart rate instability in the form of bradycardia and pauses, leading to exercise limitation and syncope. Biopacemaking aims to restore pacemaker activity by manipulating gene expression, and approaches utilising HCN channel overexpression have been widely used. We evaluated alternative gene targets for biopacemaking to restore normal SAN pacemaker physiology within bradycardic subsidiary atrial pacemaker (SAP) tissue, using the Na+ /Ca2+ exchanger NCX1, and the transcription factors TBX3 and TBX18. TBX18 expression in SAP tissue restored normal SAN function, as assessed by increased rate (SAN 267.5 ± 13.6 bpm, SAP 144.1 ± 8.6 bpm, SAP-TBX18 214.4 ± 14.4 bpm; P < 0.001), improved heart rate stability (standard deviation of RR intervals fell from 39.3 ± 7.2 ms to 6.9 ± 0.8 ms, P < 0.01; root mean square of successive differences of RR intervals fell from 41.7 ± 8.2 ms to 6.1 ± 1.2 ms, P < 0.01; standard deviation of points perpendicular to the line of identity of Poincaré plots (SD1) fell from 29.5 ± 5.8 ms to 7.9 ± 2.0 ms, P < 0.05) and restoration of isoprenaline response (increases in rates of SAN 65.5 ± 1.3%, SAP 28.4 ± 3.4% and SAP-TBX18 103.3 ± 10.2%; P < 0.001). These changes were driven by a TBX18-induced switch in the dominant HCN isoform in SAP tissue, with a significant upregulation of HCN2 (from 1.01 × 10-5  ± 2.2 × 10-6 to 2.8 × 10-5  ± 4.3 × 10-6 arbitrary units, P < 0.001). Biophysically detailed computer modelling incorporating isoform-specific HCN channel electrophysiology confirmed that the measured changes in HCN abundance could account for the observed changes in beating rates. TBX3 and NCX1 were not effective in accelerating the rate of SAP tissue.