Myocardial mechanics of percutaneous intramyocardial septal radiofrequency ablation.

OBJECTIVE: Echocardiography-guided Percutaneous IntraMyocardial Septal Radiofrequency Ablation (PIMSRA, Liwen procedure) is a novel treatment option for hypertrophic obstructive cardiomyopathy (HOCM). The impact of PIMSRA on myocardial mechanics is unknown. METHODS: Between October 2016 and June 2019, PIMSRA and 3-dimentional speckle tracking echocardiography were performed in 82 patients. Echocardiographic imaging, qualitative and quantitative clinical assessment were completed at baseline, immediately postprocedure and 1-year follow-up. RESULTS: There was a significant reduction in the peak left ventricular outflow tract (LVOT) gradients immediately following PIMSRA and at 1-year follow-up (resting gradients: from 83.50 (61.25) to 23.00 (41.75) mm Hg, p<0.001 and 13.50 (21.75) mm Hg, p<0.001, respectively; stress-induced gradients: from 118.25 (96.02) to 47.00 (74.50) mm Hg (1 year), p<0.001). There was an improvement in exercise time on stress echocardiography (p<0.001) and distance by 6 min walk test (p=0.034). Immediately after PIMSRA, there was a significant reduction in radial and circumferential strain in the ablated segments (p<0.001), with no change of longitudinal strain. At 1-year follow-up, the radial and circumferential strain recovered in the ablated segments. Meanwhile, left ventricular regional and global longitudinal strain had improved significantly (p<0.05). CONCLUSIONS: PIMSRA is an effective treatment for symptomatic HOCM that resulted in a sustained improvement in exercise capacity, a persistent decrease in LVOT gradient, and a measurable increase in myocardial contractile function. TRIAL REGISTRATION NUMBER: NCT04777188.

Thoracic Aortic Aneurysm: A Clinical Review.

Thoracic aortic aneurysms are common. Most thoracic aortic aneurysms are degenerative. However, some are associated with connective tissue disorders, bicuspid aortic valves, or familial/genetic predisposition. Most are asymptomatic, discovered incidentally on imaging. Aortic diameter is the best predictor of the natural history and risk of complications. Treating hypertension and smoking cessation can slow their growth. Surveillance imaging and referral for prophylactic aortic repair based on absolute aneurysm diameter is the primary means to decrease mortality from thoracic aortic aneurysm. We provide a practical evidence-based summary of the pathophysiology, risk factors, associated genetic syndromes, and clinical management of thoracic aortic aneurysms.

Racial and insurance disparities among patients presenting with chest pain in the US: 2009-2015.

BACKGROUND: Nationally representative studies have shown significant racial and socioeconomic disparities in the triage and diagnostic evaluation of patients presenting to the emergency department (ED) with chest pain. However, these studies were conducted over a decade ago and have not been updated amidst growing awareness of healthcare disparities. OBJECTIVE: We aimed to reevaluate the effect of race and insurance type on triage acuity and diagnostic testing to assess if these disparities persist. METHODS: We identified ED visits for adults presenting with chest pain in the 2009-2015 National Hospital Ambulatory Health Care Surveys. Using weighted logistic regression, we examined associations between race and payment type with triage acuity and likelihood of ordering electrocardiography (ECG) or cardiac enzymes. RESULTS: A total of 10,441 patients met inclusion criteria, corresponding to an estimated 51.4 million patients nationwide. When compared with white patients, black patients presenting with chest pain were less likely to have an ECG ordered (adjusted odds ratio [OR] = 0.82, 95% confidence interval [CI] = 0.69-0.99). Patients with Medicare, Medicaid, and no insurance were also less likely to have an ECG ordered compared to patients with private insurance (Medicare: OR = 0.79, CI = 0.63-0.99; Medicaid: OR = 0.67, CI = 0.53-0.84; no insurance: OR = 0.68, CI = 0.55-0.84). Those with Medicare and Medicaid were less likely to be triaged emergently (Medicare: OR = 0.84, CI = 0.71-0.99; Medicaid: OR = 0.76, CI = 0.64-0.91) and those with Medicare were less likely to have cardiac enzymes ordered (OR = 0.84, CI = 0.72-0.98). CONCLUSIONS: Persistent racial and insurance disparities exist in the evaluation of chest pain in the ED. Compared to earlier studies, disparities in triage acuity and cardiac enzymes appear to have diminished, but disparities in ECG ordering have not. Given current Class I recommendations for ECGs on all patients presenting with chest pain emergently, our findings highlight the need for improvement in this area.

Qualitative synthesis and systematic review of otolaryngology in undergraduate medical education.

OBJECTIVE: Although 25% of primary care complaints are otolaryngology related, otolaryngology instruction is not required in most medical schools. Our aim was to systematically review existing literature on the inclusion of otolaryngology in undergraduate medical education. DATA SOURCES: PubMed, Embase, Cumulative Index to Nursing and Allied Health Literature, and Education Resources Information Center. STUDY DESIGN/REVIEW METHODS: Our search encompassed all indexed years through December 29, 2014. Inclusion criteria were English language, original human data, and a focus on medical student education. Data regarding study design, teacher, educational topic, educational methods, and setting were extracted from each article. Two investigators independently reviewed all articles. RESULTS: Our initial search yielded 436 articles; 87 underwent full-text evaluation and 47 remained in the final review. The majority of studies were conducted in the United States (40%), United Kingdom (23%), and Canada (17%) and represented a single institutional experience. Studies were classified as needs assessments (36%), curriculum descriptions (15%), educational methods (36%), and skills assessments (32%); 81% were levels of evidence 3 or 4. Most reports indicated that otolaryngology rotations are not compulsory. CONCLUSIONS: Studies indicated the need for increased exposure to otolaryngology. Educational methods such as team-based learning, simulation, online learning, and clinical skills assessments may offer ways to increase exposure without overburdening clinical faculty and require further study. Data suggest that a universal otolaryngology medical student curriculum would be valuable and aid in resource sharing across institutions. We recommend that an assessment be performed to determine topics and skills that should comprise this curriculum. LEVEL OF EVIDENCE: NA.

Chemistry of ring-substituted 4-(benzothiazol-2-yl)phenylnitrenium ions from antitumor 2-(4-aminophenyl)benzothiazoles.

Ring-substituted derivatives of 2-(4-aminophenyl)benzothiazole, 1a, 1b-g, are under development as antitumor agents. One derivative, 1f, has reached phase 1 clinical trials as the prodrug 2f, Phortress (NSC 710305). These amines are activated by CYP450 1A1, apparently into hydroxylamines 8a-g that are likely metabolized into esters that ionize into nitrenium ions responsible for cellular damage. Previously we showed that 9a, the acetic acid ester of 8a, generates the long-lived (530 ns) nitrenium ion 11a by hydrolysis or photolysis in water. In this study, azide trapping shows that 9b-g generate 11b-g via rate-limiting N-O heterolysis. Ion lifetimes, estimated from azide/solvent selectivities, range from 250 to 1150 ns with identical lifetimes for 11a and 11f. Differences in biological activity of the amines are likely not due to differences in the chemistry of the cations but to differences in metabolic activation/deactivation of individual amines. Unlike the nitrenium ions, lifetimes of the esters are strongly dependent on the 3'-Me substituent. Esters containing 3'-Me (9b, 9f, 9g) have lifetimes of 5-10 s compared to 400-800 s for esters without 3'-Me (9a, 9c, 9d, 9e). This restricts 3'-Me esters to cells/tissues in which activation occurs, concentrating their effects in tumor cells if metabolism is restricted to those cells.