Background The canton of Vaud’s public health authorities, in Switzerland, invited general practitioners (GPs) to participate in managing suspected COVID-19 patients and continue caring for their non-COVID-19 patients. However, this course of action was not mandatory. The present study’s objective was to describe and understand how involved GPs were in dealing with the COVID-19 pandemic’s first wave. Methods This mixed-methods study combined a retrospective quantitative survey and a qualitative explanatory investigation. All of the canton’s GPs were invited to participate in the quantitative survey via an online questionnaire including sections on: specific organization regarding COVID-19 activities and suspected COVID-19 patients, activities relating to non-COVID-19 patients, consequences on the practice’s professional staff, and opinions about the public health authorities’ pandemic crisis management. The qualitative investigation involved interviews with 10 volunteer GPs. Results The participation rate was 41%. One third of GPs chose not to reorganize their practice for the specific management of suspected COVID-19 patients. The number of weekly activities and interventions decreased by over 50% at 44% of practices, mostly due to a lack of patients. Even in an extraordinary crisis, GPs maintained their choice of whether to become involved, as their private and independent status allowed them to do. However, those who chose to be involved felt frustrated that the public health authorities did not recognize them as major health providers in the management of the pandemic. Conclusion This study illustrated the complexity and limitations of a primary care system based completely on private healthcare providers.

A crucial method for investigating patients with coronary artery disease (CAD) is the calculation of the left ventricular ejection fraction (LVEF). It is, consequently, imperative to precisely estimate the value of LVEF-a process that can be done with myocardial perfusion scintigraphy. Therefore, the present study aimed to establish and compare the estimation performance of the quantitative parameters of the reconstruction methods filtered backprojection (FBP) and ordered-subset expectation maximization (OSEM). Methods: A beating-heart phantom with known values of end-diastolic volume, end-systolic volume, and LVEF was used. Quantitative gated SPECT/quantitative perfusion SPECT software was used to obtain these quantitative parameters in a semiautomatic mode. The Butterworth filter was used in FBP, with the cutoff frequencies between 0.2 and 0.8 cycles per pixel combined with the orders of 5, 10, 15, and 20. Sixty-three reconstructions were performed using 2, 4, 6, 8, 10, 12, and 16 OSEM subsets, combined with several iterations: 2, 4, 6, 8, 10, 12, 16, 32, and 64. Results: With FBP, the values of end-diastolic, end-systolic, and the stroke volumes rise as the cutoff frequency increases, whereas the value of LVEF diminishes. This same pattern is verified with the OSEM reconstruction. However, with OSEM there is a more precise estimation of the quantitative parameters, especially with the combinations 2 iterations · 10 subsets and 2 iterations · 12 subsets. Conclusion: The OSEM reconstruction presents better estimations of the quantitative parameters than does FBP. This study recommends the use of 2 iterations with 10 or 12 subsets for OSEM and a cutoff frequency of 0.5 cycles per pixel with the orders 5, 10, or 15 for FBP as the best estimations for the left ventricular volumes and ejection fraction quantification in myocardial perfusion scintigraphy.

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