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BACKGROUND: The coronavirus disease-19 (COVID-19) outbreak has been recently associated with lower hospitalization rates for acute coronary syndromes. Aim of the study was to investigate whether a similar behaviour is observed in admissions for urgent pacemaker implant. METHODS: This retrospective study included 1315 patients from 18 hospitals in Northern Italy with a high number of COVID-19 cases. Hospitalization rates for urgent pacemaker implant were compared between the following periods: 20 February to 20 April 2020 (case period); from 1 January to 19 February 2020 (intra-year control period); from 20 February to 20 April 2019 (inter-year control period). RESULTS: The incidence rate of urgent implants was 5.0/day in the case period, 6.0/day in the intra-year control period and 5.8/day in the inter-year control period. Incidence rate in the case period was significantly lower than both the intra-year [incidence rate ratio (IRR): 0.81, 95% CI 0.67-0.99, P = 0.040] and inter-year control periods (IRR: 0.79, 95% CI 0.66-0.95, P = 0.012); this reduction was highest after the national lockdown (IRR 0.68, 95% CI 0.52-0.91, P = 0.009). The prevalence of residents in rural areas undergoing urgent pacemaker implant was lower in the case period (36%) than in both the intra-year (47%, P = 0.03) and inter-year control periods (51%, P = 0.002). Elective pacemaker implants also decreased in the case period, with the incidence rate here being 3.5/day vs. 6.4/day in the intra-year (-45%) and 6.9/day in the inter-year period (-49%). CONCLUSION: Despite severe clinical patterns, the COVID-19 outbreak has negatively affected the population presentation to Emergency Departments for bradyarrhythmias requiring urgent pacemaker implant in Northern Italy. This mainly occurred after the national lockdown and concerned patients living in rural areas.

ImportanceApproximately 70% of individuals critically buried in avalanche debris die within 35 minutes as a result of asphyxial cardiac arrest. An artificial air-pocket device (AAPD) that separates inhaled air from exhaled air may delay the onset of severe hypoxemia and eventual asphyxia during snow burial.ObjectiveTo investigate the efficacy of a new AAPD during snow burial in a supine position.Design, Setting, and ParticipantsThis comparative effectiveness trial was performed in winter 2016 with data analysis in November 2016 and November 2022. Each trial used a simulated critical avalanche burial scenario, in which a trough was dug in a snow pile and an additional air pocket of 0.5 L volume was punched into the lateral wall for each control trial. All participants were buried in a supine position. Trials could be voluntarily terminated at any time, with a maximum length of 60 minutes; trials were automatically terminated if the participant’s peripheral oxygen saturation (Spo2) dropped to less than 84%.ExposuresEach participant conducted 2 trials, one in which they breathed into the AAPD (intervention trial) and the other in which they breathed into the prepared air pocket (control trial).Main Outcomes and MeasuresMeasurements included Spo2, cerebral oxygenation, ventilatory parameters, respiratory gas concentrations, and visual-analogue scales. Kaplan-Meier survival curves and rank test for matched survival data were used to analyze the total burial time in each trial.ResultsA total of 13 volunteers (9 men; mean [SD] age, 33 [8] years) were exposed to the intervention and control trials. Intervention trials were terminated less often (2 of 13 trials) as a result of hypoxemia than control trials (11 of 12 trials). Similarly, survival curves showed a longer duration of burial in the intervention compared with the control trials for the time to reach an Spo2 less than 84% (rank test for matched survival data: P = .003). The intervention trials, compared with the control trials, also had slower rates of decrease in fraction of inspired oxygen (mean [SD] rate, −0.8 [0.4] %/min vs −2.2 [1.2] %/min) and of increase in fraction of inspired carbon dioxide (mean [SD] rate, 0.5 [0.3] %/min vs 1.4 [0.6] %/min) and expired ventilation per minute (mean [SD] rate, 0.5 [1.0] L/min2 vs 3.9 [2.6] L/min2).Conclusions and RelevanceThis comparative effectiveness trial found that the new AAPD was associated with delaying the development of hypoxemia and hypercapnia in supine participants in a critical burial scenario. Use of the AAPD may allow a longer burial time before asphyxial cardiac arrest, which might allow longer times for successful rescue by companions or by prehospital emergency medical services.

The O2 diffusion limitation across the air blood barrier (DO2 and subcomponents Dm and Vc) was evaluated in 17 healthy participants exposed to hypobaric hypoxia (HA, 3840m, PIO2 ∼90mmHg). A 10% decrease in alveolar volume (VA) in all participants suggested the development of sub-clinical interstitial lung edema. In >80% of participants DO2/VA increased, reflecting an individual strategy to cope with the hypoxia stimulus by remodulating Vc or Dm. Opposite changes in Dm/Vc ratio were observed and participants decreasing Vc showed reduced alveolar blood capillary transit time. The interplay between diffusion and perfusion (cardiac output) was estimated in order to investigate the individual adaptive response to hypoxia. It appears remarkable that despite individual differences in the adaptive response to HA, diffusion limitation did not exceed ∼11% of the alveolar-venous PO2 gradient, revealing an admirable functional design of the air-blood barrier to defend the O2 diffusion/perfusion function when facing hypobaric hypoxia corresponding to 50mmHg decreased PAO2.

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Brustia, Raffaele, Giulia Enrione, Bruna Catuzzo, Luca Cavoretto, Massimo Pesenti Compagnoni, Enrico Visetti, Emmanuel Cauchy, Stefanie Ziegler, and Guido Giardini. Results of a prospective observational study on mountaineering emergencies in Western Alps: mind your head. High Alt Med Biol. 17:116-121, 2016.-In the northern Italian district Valle d'Aosta district during winter and summer season the population can increase up to 170% of the resident population. A prospective monocentric observational registry was held to obtain a precise picture of seasonal mountain-related medical and traumatic major events.From 1st January 2012 to 31st December 2013 all patients admitted to the Aosta Regional Hospital Emergency Room for any event occurred above 2500 m were screened: all those affected by High Altitude Illness, Acute Illness in High Altitude, Trauma, or Cold disease were prospectively included. Activity incidence rate is expressed as the occurrence of mountain-related events per 1000 hours of mountain activity. Event Incidence rate is expressed as the occurrence of new cases per 1000 hours of mountain activity.Two hundred two patients were included during the study period. Trauma (65.1% vs. 24.6%, p 0.001) and head commotive injury (48.1% vs. 15.1%, p 0.001) were more frequent during winter compared to the summer season. High altitude illness (36.9% vs. 9.3%, p 0.001) and cold pathologies (15.1% vs. 0.1%, p 0.001) occurred more frequently in summer than in winter. Patients (51.4%) were immediately discharged from emergency room, 8.4% after a 24-hour observation period, and 30.6% required hospitalization. During summer, the event risk is 0.013 per person and 1000 hours of mountain activity, while in winter, event risk amounts to 0.005 per person and 1000 hours of mountain activity.High altitude medical events or trauma represent1% of pathologies observed in the emergency room department of a mountain district in the western Alps. Head commotive injury is the most observed mountain-related event in high altitude, in winter and during ski practice. High altitude illness and cold injuries are observed more frequently in summer, during trekking or climbing activities.

Purpose: The aim of this study is to explore the physiological vascular adaptation to exposure to high altitude and to test the hypothesis that its impairment might play a role in the pathophysiology of acute mountain sickness (AMS). Methods: 34 healthy volunteers (age 38±11years, 13 women) were studied at the sea-level and after passive ascent to 3842 m (Aguille du Midi, France). Blood pressure (BP), O2 saturation (SO2), endothelial function (flow-mediated dilation, FMD), carotid distensibility coefficient (DC), carotid-femoral pulse wave velocity (PWV), peak systolic velocity in the middle cerebral artery (MCA-PSV) were performed at sea level (T0) and after 4-h hypobaric hypoxia (T1). AMS was defined as a Lake-Louise Score>5 after 24-h hypobaric hypoxia (T2). Results: At T2 12 individuals developed AMS (AMS+). AMS+ had a greater SO2 worsening at T1 as compared to AMS- (AMS+: 97.2±1.2 to 79.3±5.8%; AMS-: 97.3±1.2 to 83.1 ± 5.7%, p=0.03), with similar heart rate increase and unchanged BP. FMD was significantly reduced in AMS+ (5.75±3.01 to 3.27±1.87%, p=0.04), but not in AMS- (4.74±2.47 to 4.02±2.36%). Mean carotid diameter was increased at T1 in both groups. DC tended to be increased in AMS- but not in AMS+, while PWV was unchanged. MCA-PSV was increased in AMS-, but not in AMS+. Conclusions: In healthy asymptomatic individuals exposed to high altitude, conduit artery endothelial function is preserved in the cerebral district vasodilatation, increased elasticity and blood flow occurs. This compensatory response is early blunted in AMS+, before symptoms onset, thus suggesting a pathogenetic role.

In patients with severe systolic dysfunction the relationship between diastolic dysfunction and plasma levels of atrial and brain natriuretic peptide (ANP, BNP), catecholamines, renin, and aldosterone in patients with chronic heart failure (CHF) has never been investigated.The aim of this study was to evaluate in clinically stable patients with severe systolic dysfunction whether the presence of diastolic restrictive pattern modifies neurohormonal plasma levels.Of 82 consecutive patients with stable CHF, 36 were in sinus rhythm, had an adequate ultrasound window and an ejection fraction30%, and gave their written consent. Plasma levels of ANP, BNP, aldosterone, renin, epinephrine, and norepinephrine were assessed, and the diastolic function was evaluated by Doppler transmitral flow velocity curves.Except for aldosterone, plasma levels of the other hormones were above normal range in most patients. Patients with restrictive pattern (22%) had BNP plasma levels significantly higher than patients with nonrestrictive pattern (78%): 251 +/- 196 versus 44 +/- 35 ng/L (P=.02). A BNP value of 72.6 ng/L had a sensitivity of 88%, with a specificity of 89% for detecting restrictive pattern in our population.In clinically stable patients with CHF and severe systolic dysfunction, BNP is the only neurohormone sensitive to the concomitant presence of a restrictive pattern.