Adult spiny mice (Acomys) exhibit endogenous cardiac recovery in response to myocardial infarction

Complex tissue regeneration is extremely rare among adult mammals. An exception, however, is the superior tissue healing of multiple organs in spiny mice (Acomys). While Acomys species exhibit the remarkable ability to heal complex tissue with minimal scarring, little is known about their cardiac structure and response to cardiac injury. In this study, we first examined baseline Acomys cardiac anatomy and function in comparison with commonly used inbred and outbred laboratory Mus strains (C57BL6 and CFW). While our results demonstrated comparable cardiac anatomy and function between Acomys and Mus, Acomys exhibited a higher percentage of cardiomyocytes displaying distinct characteristics. In response to myocardial infarction, all animals experienced a comparable level of initial cardiac damage. However, Acomys demonstrated superior ischemic tolerance and cytoprotection in response to injury as evidenced by cardiac functional stabilization, higher survival rate, and smaller scar size 50 days after injury compared to the inbred and outbred mouse strains. This phenomenon correlated with enhanced endothelial cell proliferation, increased angiogenesis, and medium vessel maturation in the peri-infarct and infarct regions. Overall, these findings demonstrate augmented myocardial preservation in spiny mice post-MI and establish Acomys as a new adult mammalian model for cardiac research.

Comparative Effectiveness of Virtual Reality (VR) vs 3D Printed Models of Congenital Heart Disease in Resident and Nurse Practitioner Educational Experience

Background: Medical trainees frequently note that cardiac anatomy is difficult to conceive within a two dimensional framework. The dynamics of flow and nuances of defects become more apparent when framed in three-dimensional models. Given the evidence of improved comprehension using such modeling, this study aimed to contribute further to that understanding by comparing Virtual Reality (VR) and 3D printed models (3DP) in medical education. Objectives: We sought to systematically compare the perceived subjective effectiveness of Virtual Reality (VR) and 3D printed models (3DP) in the educational experience of residents and nurse practitioners. Methods: Trainees and practitioners underwent individual 15-minute teaching sessions in which features of an anatomically normal heart as well as a congenitally diseased heart were demonstrated using both Virtual Reality (VR) and 3-D printed models (3DP). Participants then briefly explored each modality before filling out a short survey in which they identified which model (3DP or VR) they felt was more effective in enhancing their understanding of cardiac anatomy and associated defects. The survey included a binary summative assessment and a series of Likert scale questions addressing usefulness of each model type and degree of comfort with each modality. Results: 27 pediatric residents and 3 nurse practitioners explored models of normal heart and tetralogy of Fallot pathology. Participants endorsed a greater degree of understanding with VR models (8.5±1) compared with 3D Printed models (6.3±1.8) or traditional models of instruction (5.5±1.5) p<0.001. Most participants had minimal prior exposure to VR (1.1 ± 0.4) or 3-D printed models (2.1 ± 1.5). Most participants felt comfortable with modern technology (7.6 ± 2.1). 87% of participants preferred VR over 3DP. Conclusions: Our study shows that, overall, VR was preferred over 3DP models by pediatric residents and nurse practitioners for understanding cardiac anatomy and pathophysiology.

Relationship Between the Coronary Artery Calcium (CAC) Score and the Angle Between the Aortic Valve and the Left Ventricular Inflow Long Axis (AV-LV) as Cardiovascular Risk Factors

Background: Cardiovascular disease (CVD) is one of the leading causes of mortality in both developed and developing countries. Therefore, identification of CVD risk factors is one of the most important steps in preventing this disease. Evidence suggests that imaging of the cardiac anatomy can be helpful for risk assessment. Objectives: This study aimed to assess two cardiac anatomy features, namely, the angle between the aortic valve and the left ventricular inflow long axis (AV-LV angle) and the coronary artery calcium (CAC) score. Patients and Methods: This cross-sectional study was conducted on 74 patients with indications for computed tomography angiography (CTA) according to the American Heart Association (AHA) guidelines from July 2019 to January 2020 in Iran. The Agatston method was applied to measure the CAC score. Besides, to determine the AV-LV angle, the angle between a line tangent to the aortic valve leaflets and a line through the center of the aorta toward the left ventricular apex was measured. The patients’ baseline characteristics were also documented by conducting interviews. Results: Of 74 patients, 56% were male. The mean age of the patients was 54.41 ± 12.31 years, and their mean body mass index (BMI) was 26.71 ± 3.89 kg/m2. The frequency of smoking was 28% among the participants. A history of hypertension was reported in 38.7% of the patients, and a history of dyslipidemia was reported in 36%. Besides, the history of myocardial infarction was reported in 4% of the patients, diabetes mellitus in 9.3% of the patients, and angioplasty in 6% of the patients. The CAC score only had significant relationships with hypertension and age (correlation coefficients = 0.51). On the other hand, the AV-LV angle had no significant relationship with the patients’ baseline characteristics. The statistical analysis of the AV-LV angle and CAC score showed no significant relationship between these parameters (P = 0.756). Conclusion: The AV-LV angle and the CAC score were not significantly associated. Further research is recommended to fill the knowledge gap regarding the cardiac anatomy features for cardiovascular risk assessment.