Drivers of iPad use by undergraduate medical students: the Technology Acceptance Model perspective.

BACKGROUND: Medical students need to acquire a continuously growing body of knowledge during their training and throughout their practice. Medical training programs should aim to provide students with the skills to manage this knowledge. Mobile technology, for example, could be a strategy used through training and practice. The objective of this study was to identify drivers of using mobile technology (an iPad) in a UGME preclinical settings and to study the evolution of those drivers over time. METHODS: We solicited all students from two cohorts of a preclinical component of a Canadian UGME program. They were asked to answer two online surveys: one on their first year of study and another on the second year. Surveys were built based on the Technology Acceptance Model (TAM) to which other factors were also added. Data from the two cohorts were combined and analysed with partial least squares structural equation modelling (PLS-SEM) to test two measurement models, one for each year. RESULTS: We tested fifteen hypotheses on both data sets (first year and second year). Factors that explained the use of an iPad the first year were knowledge, preferences, perceived usefulness and anticipation. In the second year, perceived usefulness, knowledge and satisfaction explained the use of an iPad. Other factors have also significantly, but indirectly influenced the use of the iPad. CONCLUSIONS: We identified factors that influenced the use of an iPad in a preclinical medical program. These factors differed from the first year to the second year in the program. Our results suggest that interventions should be tailored for different point in time to foster the use of an iPad. Further study should investigate how interventions based on these factors may influence implementation of mobile technology to help students acquire ability to navigate efficiently through medical knowledge.

The feasibility, reliability, and incremental value of two-dimensional speckle-tracking for the detection of significant coronary stenosis after treadmill stress echocardiography.

BACKGROUND: Two-dimensional speckle-tracking echocardiography (STE) may help detect coronary artery disease (CAD) when combined with dobutamine stress echocardiography. However, few studies have explored STE with exercise stress echocardiography (ESE). We aimed to evaluate the feasibility, reliability, and incremental value of STE combined with treadmill ESE compared to treadmill ESE alone to detect CAD. METHODS: We conducted a case-control study of all consecutive patients with abnormal ESE in 2018-2020 who subsequently underwent coronary angiography within a six-month interval. We 1:1 propensity score-matched these patients to those with a normal ESE. Two blinded operators generated a 17-segment bull's-eye map of longitudinal strain (LS). We utilized the mean differences between stress and baseline LS values in segments 13-17, segment 17, and segments 15-16 to create receiver operator curves for the overall examination, the left anterior descending artery (LAD), and the non-LAD territories, respectively. RESULTS: We excluded 61 STEs from 201 (30.3%) eligible ESEs; 47 (23.4%) because of suboptimal image quality and 14 (7.0%) because of excessive heart rate variability precluding the calculation of a bull's-eye map. After matching, a total of 102 patients were included (51 patients in each group). In the group with abnormal ESE patients (mean age 66.4 years, 39.2% female), 64.7% had significant CAD (> 70% stenosis) at coronary angiogram. In the group with normal ESE patients (mean age 65.1 years, 35.3% female), 3.9% were diagnosed with a new significant coronary stenosis within one year. The intra-class correlation for global LS was 0.87 at rest and 0.92 at stress, and 0.84 at rest, and 0.89 at stress for the apical segments. The diagnostic accuracy of combining ESE and STE was superior to visual assessment alone for the overall examination (area under the curve (AUC) = 0.89 vs. 0.84, p = 0.025), the non-LAD territory (AUC = 0.83 vs. 0.70, p = 0.006), but not the LAD territory (AUC = 0.79 vs. 0.73, p = 0.11). CONCLUSIONS: Two-dimensional speckle-tracking combined with treadmill ESE is relatively feasible, reliable, and may provide incremental diagnostic value for the detection and localization of significant CAD.

Case report of an unusual and catastrophic presentation of coral reef aorta.

BACKGROUND: Coral reef aorta (CRA) is a rare condition characterized by atherosclerosis and overt calcification of the aorta leading to severe luminal stenosis of the vessel. Most patients present with hypertension and intermittent claudication at the time of diagnosis. Risk factors associated with this condition are essentially the same as those associated with atherosclerosis. However, no unique condition seems to predispose an individual to develop CRA. CASE SUMMARY: We describe the case of a patient known for rheumatoid arthritis (RA) treated with long-term systemic corticosteroids who presented with a shock of unknown aetiology and left ventricular ejection fraction of 10%. Conventional and computed tomography angiography showed a CRA with subtotal lesion of the aortic arch that led to cardiogenic shock. DISCUSSION: Even though the exact aetiology of her condition will remain uncertain, RA and extended use of corticosteroids likely played a role in the development of this severe form of CRA.

Right ventricular end-diastolic wall stress: does it impact on right atrial size, and does it differ in right ventricular pressure vs volume loading conditions?

BACKGROUND: Right ventricular (RV) diastolic dysfunction precedes RV systolic dysfunction. Improvement in noninvasive assessment of RV diastolic function may enable earlier detection of RV dysfunction, especially important in the assessment of patients with congenital heart disease. We investigated a new parameter we call RV end-diastolic wall stress (RVEDWS) in an effort to better characterize RV diastolic function. METHODS: We retrospectively studied consecutive adults with right-sided congenital heart disease between January 2005 and November 2006. RVEDWS was calculated with the Laplace law: r × p/λ, where r = basal RV dimension at end-diastole, p = RV end-diastolic pressure obtained from catheterization of the right side of the heart, and λ = thickness of RV free wall at end-diastole in the subcostal view. Calculated RVEDWS was correlated to echocardiographically derived right atrial (RA) measurements by means of the Pearson correlation. RESULTS: Twenty-four patients, aged 41 ± 15 years, were included in the study. Mean RVEDWS was 20 ± 11 g/cm(2) (range, 3-46 g/cm(2)). RVEDWS correlated significantly with RA area and volume (r = 0.71, P < 0.0001; r = 0.69, P < 0.001, respectively). An RVEDWS > 17 g/cm(2) had a sensitivity of 91% and specificity of 85% in predicting significant RA enlargement. RVEDWS was significantly higher in patients with RV volume overload compared with those with pressure or normal loading conditions (28 g/cm(2) vs 17 g/cm(2), P = 0.01). CONCLUSIONS: RVEDWS correlates significantly with RA size and differs considerably between RV volume and pressure overload states. Further work is needed to determine whether this RV diastolic parameter can be predictive of clinical outcomes in patients with RV loading lesions.

Reduction of delays in primary percutaneous coronary intervention.

BACKGROUND: Acute myocardial infarction is a major health issue. Primary percutaneous coronary intervention (PPCI) for ST-elevation myocardial infarction was proved to be superior to fibrinolytic therapy in many randomized trials when done in a timely manner. However, PPCI is associated with delays. Studies have shown that greater delay is associated with increased mortality rate. We applied simple interventions to reduce door-to-balloon time. Our study goal was to evaluate the reduction of delays after our interventions and to monitor 30-day mortality. METHODS: A prospective registry was created to evaluate delays and mortality associated with PPCI. Measures such as annual feedback with suggestions were taken to minimize the delays. Door-to-balloon delays before and after the interventions were compared. RESULTS: A total of 1361 primary PCIs were performed from 2005 to 2008. Of these cases, 1071 patients were transferred from community hospitals. The median door-to-balloon time for transferred patients was 142 minutes for 2005, 138 minutes for 2006, 125 minutes for 2007, and 121 minutes for 2008 (P < 0.001 for 2005 vs. 2008). Door-to-balloon time for patients admitted directly to our centre was 87 minutes in 2005, 74.5 minutes in 2006, 73.5 minutes in 2007, and 74.0 minutes in 2008 (P < 0.001 for 2005 vs. 2008). Thirty-day mortality of these consecutive patients is low (5.2% for 2005 and 3.8% for 2008; P = not significant). CONCLUSIONS: Inexpensive and simple interventions may significantly reduce primary PCI-related delays for transferred cases and patients admitted directly to a centre with PPCI facilities. We also observed a low mortality rate for those consecutive patients.

Right atrial size relates to right ventricular end-diastolic pressure in an adult population with congenital heart disease.

AIM: Noninvasive markers of right ventricular (RV) diastolic dysfunction are limited by their lack of reproducibility and accuracy. We tested the hypothesis that right atrial (RA) size measured by echocardiography was correlated to invasive parameters of RV diastolic filling. METHODS AND RESULTS: We studied 31 consecutive adult patients with congenital heart disease. From 2D echocardiography images, we measured maximal RA long-axis and short-axis lengths, area and volume. We compared each of these measures to right ventricular end-diastolic pressure (RVEDP) and mean right atrial pressure (mRAP) measured by right heart catheterization. RA long-axis, short-axis, area, and volume correlated significantly with RVEDP (r = 0.78, P < 0.001; r = 0.61, P < 0.001; r = 0.79, P < 0.001; and r = 0.75, P < 0.001, respectively) and mRAP (r = 0.66, P < 0.001; r = 0.56, P = 0.002; r = 0.70, P < 0.001; r = 0.68, P < 0.001, respectively). Single cut points for each echocardiographic parameter demonstrated reasonable accuracy to rule-in and rule-out RVEDP ≥ 7 mm Hg (sensitivity = 74%, specificity = 82%, positive LR = 4.1, negative LR = 0.32 for RA long-axis of 49 mm; sensitivity = 89%, specificity = 82%, positive LR = 4.9, negative LR = 0.12 for RA area of 14 cm²; sensitivity = 89%, specificity = 82%, positive LR = 4.9, negative LR = 0.13 for RA volume of 37 mL). CONCLUSION: RA size measured by echocardiography is strongly correlated to invasive parameters of RV diastolic filling and predicts high RV end-diastolic pressure.

Same-day transfer of patients with unstable angina and non-ST segment elevation myocardial infarction back to their referring hospital after angioplasty.

BACKGROUND: Recent evidence has shown the advantages of an early invasive strategy for patients with high-risk unstable angina (UA) and non-ST segment elevation myocardial infarction (NSTEMI). However, the number of beds available for postangioplasty monitoring limits the use of this approach at the Centre hospitalier universitaire de Sherbrooke (Fleurimont, Quebec). OBJECTIVES: To study the safety of a protocol allowing the same-day return of patients with UA or NSTEMI to their referring hospital after angioplasty at the Centre hospitalier universitaire de Sherbrooke. METHODS: From June 2001 to June 2003, of the 532 patients with UA and NSTEMI who underwent percutaneous coronary intervention with planned same-day transfer back to their referring hospital, 419 consecutive patients who were eligible to return the same day were prospectively followed for 24 h. RESULTS: Stents were used in 94.7% of patients and platelet glycoprotein IIb/IIIa receptor antagonists were used in 34.8% of patients. For 85% of patients, the femoral artery was used as the access route for percutaneous coronary intervention. The mean time that patients stayed in the hospital after angioplasty before returning to their referring centres was 4.4 h. No deaths, life-threatening arrhythmias or urgent revascularizations were reported during the 24 h postangioplasty follow-up period, but one patient had a major bleeding complication. During the study period, the mean angioplasty waiting time decreased from 5.7 days to 2.1 days. CONCLUSIONS: The protocol evaluated in the present article is safe. It frees more beds, thus reducing the waiting list and allowing patients with high-risk acute coronary syndromes without ST segment elevation from community hospitals to benefit from the advantages of an early invasive strategy.