Modeling Diagnostic Expertise in Cases of Irreducible Uncertainty: The Decision-Aligned Response Model.

PURPOSE: Assessing expertise using psychometric models usually yields a measure of ability that is difficult to generalize to the complexity of diagnoses in clinical practice. However, using an item response modeling framework, it is possible to create a decision-aligned response model that captures a clinician's decision-making behavior on a continuous scale that fully represents competing diagnostic possibilities. In this proof-of-concept study, the authors demonstrate the necessary statistical conceptualization of this model using a specific electrocardiogram (ECG) example. METHOD: The authors collected a range of ECGs with elevated ST segments due to either ST-elevation myocardial infarction (STEMI) or pericarditis. Based on pilot data, 20 ECGs were chosen to represent a continuum from "definitely STEMI" to "definitely pericarditis," including intermediate cases in which the diagnosis was intentionally unclear. Emergency medicine and cardiology physicians rated these ECGs on a 5-point scale ("definitely STEMI" to "definitely pericarditis"). The authors analyzed these ratings using a graded response model showing the degree to which each participant could separate the ECGs along the diagnostic continuum. The authors compared these metrics with the discharge diagnoses noted on chart review. RESULTS: Thirty-seven participants rated the ECGs. As desired, the ECGs represented a range of phenotypes, including cases where participants were uncertain in their diagnosis. The response model showed that participants varied both in their propensity to diagnose one condition over another and in where they placed the thresholds between the 5 diagnostic categories. The most capable participants were able to meaningfully use all categories, with precise thresholds between categories. CONCLUSIONS: The authors present a decision-aligned response model that demonstrates the confusability of a particular ECG and the skill with which a clinician can distinguish 2 diagnoses along a continuum of confusability. These results have broad implications for testing and for learning to manage uncertainty in diagnosis.

New Approaches to Donor Selection and Preparation in Heart Transplantation.

PURPOSE OF REVIEW: With increasing survival of patients with stage D heart failure, the demand for heart transplantation has increased. The supply of donor hearts remains relatively limited. Strategies have been investigated and new technologies have been developed to expand the current donor pool. These new approaches will be discussed herein. RECENT FINDINGS: Donor hearts are often considered "marginal" due to risk factors such as older age, size mismatch with the intended recipient, prolonged ischemic time, presence of left ventricular hypertrophy, and hepatitis B/C infection. We reviewed recent data regarding the use of donor hearts with these risk factors and suggest ways to safely liberalize current donor heart acceptance criteria. New technologies such as temperature-controlled transport systems and ex vivo cardiac perfusion methods have also demonstrated promising short-term and intermediate outcomes as compared with routine cold storage, by promoting heart preservation and enabling heart procurement from remote sites with shorter cold ischemic time. Recent use of hearts from donation after circulatory death donors has demonstrated comparable outcomes to conventional donation after brain death, which can further expand the current donor pool. SUMMARY: Careful selection of "marginal" donor hearts, use of ex vivo cardiac perfusion, and acceptance of hearts after circulatory death may expand our current cardiac donor pool with comparable outcomes to conventional donor selection and preparation methods.

Exercise Training for Cancer Survivors.

OPINION STATEMENT: Cardiovascular diseases are a common cause of morbidity and mortality in cancer survivors. Furthermore, some cancer therapies are now being increasingly recognized to have negative cardiovascular effects, or cardiotoxicity. Exercise therapy has been found to improve cardiorespiratory fitness in patients with cancer as well as attenuate the cardiotoxic effects of cancer therapy. It is the centerpiece for cardiac and pulmonary rehabilitation programs. It is also an important component in cardio-oncology rehabilitation. Exercise is generally safe, and its benefit is observed when started as soon as the diagnosis of cancer and throughout cancer survivorship.

Spinal cord infarction remote from maximal compression in a patient with Morquio syndrome.

Morquio syndrome, or mucopolysaccharidosis type IV, is a rare enzyme deficiency disorder and results in skeletal dysplasia. Odontoid dysplasia is common among affected patients, resulting in atlantoaxial instability and spinal cord compression. Surgical treatments include decompression and prophylactic fusion, during which intraoperative neuromonitoring is important to alert the surgical team to changes in cord function so that they can prevent or mitigate spinal cord injury. This report describes a 16-year-old girl with Morquio syndrome who developed paraplegia due to thoracic spinal cord infarction during foramen magnum and atlantal decompression. This tragic event demonstrates the following: 1) that patients with Morquio syndrome are at risk for ischemic spinal cord injury at levels remote from areas of maximal anatomical compression while under anesthesia in the prone position, possibly due to impaired cardiac output; 2) the significance of absent motor evoked potential responses in the lower limbs with preserved upper-limb responses in an ambulatory patient; 3) the importance of establishing intraoperative neuromonitoring baseline assessments prior to turning patients to the prone position following induction of anesthesia; and 4) the importance of monitoring cardiac output during prone positioning in patients with chest wall deformity.

Endoscopic fenestration of cavum velum interpositum cysts: a case study of two symptomatic patients.

INTRODUCTION: Cavum velum interpositum (CVI) is commonly an incidental asymptomatic finding on imaging studies. Encystment can occur and, in most situations, is also asymptomatic. Clinical symptoms occurring in patients with CVI cysts have been reported infrequently with the result that the relationship of these symptoms and the cyst are usually unclear. This report contributes to the knowledge base of symptoms that can occur in patients with CVI and the response of symptoms to effective treatment. PATIENTS AND METHODS: We report the clinical outcomes of a 3-year-old male patient and a 13-year-old female patient with symptoms and CVI cysts on imaging who were treated successfully with endoscopic fenestration. RESULTS: The developmental delay and occasional headache present in the 3-year-old male patient resolved after endoscopic fenestration; however, the 13-year-old patient who had neuropsychiatric symptoms did not improve. CONCLUSIONS: Our cases add to the literature describing the response to cyst treatment in symptomatic patients harboring CVI cysts. Symptoms due to CSF pathway obstruction may respond to cyst fenestration, while the response of symptoms in patents who do not have clear CSF circulation disorders is less predictable.