Recurrent, life-threatening PE in the setting of popliteal vein aneurysm in pregnancy: a case report.

BACKGROUND: Popliteal vein aneurysms (PVA) are a rare clinical entity with unknown etiology that pose a significant risk for venous thromboembolic events (VTE). The current literature supports anticoagulation and operative management. There are few case reports of PVA in pregnancy. We present a unique case of a pregnant patient with recurrent pulmonary embolism (PE) in the setting of PVA with intra-aneurysmal thrombosis who ultimately underwent surgical excision. CASE PRESENTATION: A previously healthy 34-year-old G2P1 at 30 weeks gestation presented to the emergency department with shortness of breath and chest pain. She was diagnosed with PE and subsequently required intensive care unit (ICU) admission and thrombolysis for a massive PE. While on a therapeutic dose of tinzaparin she had recurrence of PE in the post-partum period. She was treated with supratherapeutic tinzaparin and subsequently transitioned to warfarin. She was found to have a PVA and ultimately underwent successful PVA ligation. She remains on anticoagulation for secondary prevention of VTE. CONCLUSIONS: PVA are a rare but potentially fatal source of VTE. Patients most commonly present with symptoms of PE. The risk of VTE is elevated in the pro-thrombotic states of pregnancy and the post-partum period due to both physiologic and anatomical changes. The recommended management of PVA with PE is anticoagulation and surgical resection of the aneurysm, however this can be complicated in the setting of pregnancy. We demonstrated that pregnant patients with PVA can be temporized with medical management to avoid surgical intervention during pregnancy, but require close symptom monitoring and serial imaging to reassess the PVA, with high index of suspicion for recurrent VTE. Ultimately, patients with PVA and PE should undergo surgical resection to reduce the risk of recurrence and long-term complications. The ideal duration of post-operative anticoagulation remains unclear, and should likely be decided on based on risks, benefits, values, and shared decision making with the patient and their care provider.

Canadian Cardiovascular Society 2022 Guidelines for Peripheral Arterial Disease.

Patients with widespread atherosclerosis such as peripheral artery disease (PAD) have a high risk of cardiovascular and limb symptoms and complications, which affects their quality of life and longevity. Over the past 2 decades there have been substantial advances in diagnostics, pharmacotherapy, and interventions including endovascular and open surgical to aid in the management of PAD patients. To summarize the evidence regarding approaches to diagnosis, risk stratification, medical and intervention treatments for patients with PAD, guided by the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) framework, evidence was synthesized, and assessed for quality, and recommendations provided-categorized as weak or strong for each prespecified research question. Fifty-six recommendations were made, with 27% (15/56) graded as strong recommendations with high-quality evidence, 14% (8/56) were designated as strong recommendations with moderate-quality evidence, and 20% (11/56) were strong recommendations with low quality of evidence. Conversely 39% (22/56) were classified as weak recommendations. For PAD patients, strong recommendations on the basis of high-quality evidence, include smoking cessation interventions, structured exercise programs for claudication, lipid-modifying therapy, antithrombotic therapy with a single antiplatelet agent or dual pathway inhibition with low-dose rivaroxaban and aspirin; treatment of hypertension with an angiotensin converting enzyme or angiotensin receptor blocker; and for those with diabetes, a sodium-glucose cotransporter 2 inhibitor should be considered. Furthermore, autogenous grafts are more effective than prosthetic grafts for surgical bypasses for claudication or chronic limb-threatening ischemia involving the popliteal or distal arteries. Other recommendations indicated that new endovascular techniques and hybrid procedures be considered in patients with favourable anatomy and patient factors, and finally, the evidence for perioperative risk stratification for PAD patients who undergo surgery remains weak.

Antithrombotics in stable peripheral artery disease.

Patients with peripheral artery disease (PAD) are at high risk for ischemic cardiovascular complications. While single antiplatelet therapy (SAPT), predominantly aspirin, has long been the standard antithrombotic treatment in stable PAD, there have now been greater than 40,000 PAD patients randomized to varying antiplatelet and/or anticoagulant regimens. In this review, we provide a summary of the current evidence for antithrombotics in stable PAD, focusing on the rates of major adverse cardiovascular events (MACE), major adverse limb events (MALE), and major bleeding. SAPT has a limited role in the treatment of asymptomatic PAD, particularly in the absence of concomitant coronary artery disease. In symptomatic PAD, SAPT is effective in preventing MACE, though treatment with a thienopyridine appears marginally superior to aspirin. Dual antiplatelet therapy (DAPT) suggests benefit over SAPT in reducing MACE and MALE, though studies to date are not conclusive and/or are associated with excess major bleeding. Combining moderate to high intensity vitamin K antagonists with antiplatelet therapy does not reduce MACE or MALE and increases life-threatening bleeding. Rivaroxaban 2.5 mg BID in addition to aspirin reduces the incidence of both MACE and MALE as compared to aspirin alone, without increasing life-threatening bleeding. This regimen is associated with a reduced severity of MALE when it does occur. Comparisons across antithrombotic trials in PAD are challenging given the heterogeneity of patient populations and the differing assessment of outcomes. The vascular medicine practitioner can reduce ischemic cardiac and limb events, as well as minimize life-threatening bleeding, by choosing the optimal antithrombotic regimen in their PAD patients.

Sex differences in associations between insulin resistance, heart rate variability, and arterial stiffness in healthy women and men: a physiology study.

Diabetes confers greater cardiovascular risk to women than to men. Whether insulin-resistance-mediated risk extends to the healthy population is unknown. Measures of insulin resistance (fasting insulin, homeostatic model assessment, hemoglobin A1c, quantitative insulin sensitivity check index, glucose) were determined in 48 (56% female) healthy subjects. Heart rate variability (HRV) was calculated by spectral power analysis and arterial stiffness was determined using noninvasive applanation tonometry. Both were measured at baseline and in response to angiotensin II infusion. In women, there was a non-statistically significant trend towards increasing insulin resistance being associated with an overall unfavourable HRV response and increased arterial stiffness to the stressor, while men demonstrated the opposite response. Significant differences in the associations between insulin resistance and cardiovascular physiological profile exist between healthy women and men. Further studies investigating the sex differences in the pathophysiology of insulin resistance in cardiovascular disease are warranted.

The attributes of an effective teacher differ between the classroom and the clinical setting.

Most training programs use learners' subjective ratings of their teachers as the primary measure of teaching effectiveness. In a recent study we found that preclinical medical students' ratings of classroom teachers were associated with perceived charisma and physical attractiveness of the teacher, but not intellect. Here we explored whether the relationship between these variables and teaching effectiveness ratings holds in the clinical setting. We asked 27 Internal Medicine residents to rate teaching effectiveness of ten teachers with whom they had worked on a clinical rotation, in addition to rating each teacher's clinical skills, physical attractiveness, and charisma. We used linear regression to study the association between these explanatory variables and teaching effectiveness ratings. We found no association between rating of physical attractiveness and teaching effectiveness. Clinical skill and charisma were independently associated with rating of teaching effectiveness (regression coefficients [95 % confidence interval] 0.73 [0.60, 0.85], p < 0.001 and 0.12 [0.01, 0.23], p = 0.03, respectively). The variables associated with effectiveness of classroom and clinical teachers differ, suggesting context specificity in teaching effectiveness ratings. Context specificity may be explained by differences in the exposure that learners have to teachers in the classroom versus clinical setting-so that raters in the clinical setting may base ratings upon observed behaviours rather than stereotype data. Alternatively, since subjective ratings of teaching effectiveness inevitably incorporate learners' context-specific needs, the attributes that make a teacher effective in one context may not meet the needs of learners in a different context.

Vitamin B12 deficiency with combined hematological and neuropsychiatric derangements: a case report.

INTRODUCTION: Although vitamin B12 deficiency is a well-known cause of hematological and neuropsychiatric illness, the presentation of combined severe pancytopenia, demyelination and prominent psychiatric impairment is rare. CASE PRESENTATION: We present a case of a previously healthy 55-year-old East African man with severe vitamin B12 deficiency (serum vitamin B12 22pmol/L) secondary to pernicious anemia. He had a severe hypoproliferative megaloblastic anemia with hemolysis (hemoglobin 61g/L, mean corpuscular volume 99fL, reticulocytes 0.8%, haptoglobin undetectable), leukopenia (2.7×109/L), thrombocytopenia (96×109/L), ataxia with central demyelination, and megaloblastic madness. The patient's anemia, myelopathy and psychiatric condition responded well to parenteral vitamin B12 replacement therapy, with significant improvement seen within weeks. CONCLUSION: Hematological manifestations of vitamin B12 deficiency are typically inversely correlated with the presence and severity of neuropsychiatric impairment. Although uncommon, a presentation with severe hematological and neuropsychiatric disease can occur, as illustrated by this case. Its presence may help guide diagnosis as well as provide clinically important prognostic information.

How do medical students form impressions of the effectiveness of classroom teachers?

CONTEXT: Teaching effectiveness ratings (TERs) are used to provide feedback to teachers on their performance and to guide decisions on academic promotion. However, exactly how raters make decisions on teaching effectiveness is unclear. OBJECTIVES: The objectives of this study were to identify variables that medical students appraise when rating the effectiveness of a classroom teacher, and to explore whether the relationships among these variables and TERs are modified by the physical attractiveness of the teacher. METHODS: We asked 48 Year 1 medical students to listen to 2-minute audio clips of 10 teachers and to describe their impressions of these teachers and rate their teaching effectiveness. During each clip, we displayed either an attractive or an unattractive photograph of an unrelated third party. We used qualitative analysis followed by factor analysis to identify the principal components of teaching effectiveness, and multiple linear regression to study the associations among these components, type of photograph displayed, and TER. RESULTS: We identified two principal components of teaching effectiveness: charisma and intellect. There was no association between rating of intellect and TER. Rating of charisma and the display of an attractive photograph were both positively associated with TER and a significant interaction between these two variables was apparent (p < 0.001). The regression coefficient for the association between charisma and TER was 0.26 (95% confidence interval [CI] 0.10-0.41) when an attractive picture was displayed and 0.83 (95% CI 0.66-1.00) when an unattractive picture was displayed (p < 0.001). CONCLUSIONS: When medical students rate classroom teachers, they consider the degree to which the teacher is charismatic, although the relationship between this attribute and TER appears to be modified by the perceived physical attractiveness of the teacher. Further studies are needed to identify other variables that may influence subjective ratings of teaching effectiveness and to evaluate alternative strategies for rating teaching effectiveness.

Neuromuscular adaptations following antagonist resisted training.

The purpose was to assess a novel form of strength training, antagonist resisted training (ART), with potential use in microgravity and athletic rehabilitation settings. ART uses the force from antagonist muscles, during cocontractions, as the source of resistance for the agonists. Strength and electromyography (EMG) measurements were recorded before and after a 6-week training program during which participants trained the left arm while the right arm served as a control. Training was designed so that the elbow extensors (antagonists) served as resistance for the elbow flexors (agonists). Elbow flexor and extensor strengths were measured during maximal isometric contractions with the elbow fixed at 90 degrees. EMG was recorded from the biceps brachii and lateral head of the triceps brachii during all strength tests. EMG was also recorded from both muscles during a maximal isometric cocontraction of the elbow flexors and extensors. Elbow flexion strength increased significantly for the trained arm (5.8%) relative to the control (0.5%) (p = 0.003). Elbow extension strength of the trained limb also increased significantly (8.5%) relative to the control (4.5%) (p = 0.029). Biceps and triceps EMG, during maximum strength tests, increased significantly for the trained arm (18.5 and 18.6%) relative to the control (0.5 and -5.2%) (p = 0.035 and p = 0.01). Biceps and triceps EMG, during maximum cocontraction tests, increased significantly for the trained arm (30.1 and 61.1%) relative to the control (9.2 and 1.1%) (p = 0.042 and p = 0.0005). ART was found to increase strength and therefore could be an effective form of resistance training. Because it requires no equipment, ART may be especially applicable in microgravity environments, which have space and weight constraints.