BackgroundDuring the COVID-19 pandemic, the use of protection masks is essential to reduce contagions. However, public opinion reports an associated subjective shortness of breath. We evaluated cardiorespiratory parameters at rest and during maximal exertion to highlight any differences with the use of protection masks.MethodsTwelve healthy subjects underwent three cardiopulmonary exercise tests: without wearing protection mask, with surgical and with FFP2 mask. Dyspnea was assessed by Borg Scale. Standard pulmonary function tests were also performed.ResultsAll the subjects (40.8±12.4 years; 6 males) completed the protocol with no adverse event. At spirometry, from no mask to surgical to FFP2, a progressive reduction of FEV1 and FVC was observed (3.94±0.91 l, 3.23±0.81 l, 2.94±0.98 l and 4.70±1.21 l, 3.77±1.02 l, 3.52±1.21 l, respectively, p<0.001). Rest ventilation, O2 uptake (V̇O2) and CO2 production (VCO2) were progressively lower with a reduction of respiratory rate. At peak exercise, subjects revealed a progressively higher Borg scale when wearing surgical and FFP2. Accordingly, at peak exercise, V̇O2 (31.0±23.4, 27.5±6.9, 28.2±8.8 ml/kg/min, p=0.001), ventilation (92±26, 76±22, 72±21 l, p=0.003), respiratory rate (42±8, 38±5, 37±4, p=0.04) and tidal volume (2.28±0.72, 2.05±0.60, 1.96±0.65 l, p=0.001) were gradually lower. We did not observed a significant difference in oxygen saturation.ConclusionsProtection masks are associated with significant but modest worsening of spirometry and cardiorespiratory parameters at rest and peak exercise. The effect is driven by a ventilation reduction due to an increased airflow resistance. However, since exercise ventilatory limitation is far from being reached, their use is safe even during maximal exercise, with a slight reduction in performance.

SUMMARY Aim:To assess the effect of chronotropic incompetence on functional capacity in chronic heart failure (CHF) patients, as evaluated as NYHA and peak oxygen consumption (pVO 2 ), focusing on the presence and dose of β-blocker treatment. Methods: Nine hundred and sixty-seven consecutive CHF patients were evaluated, 328 of whom were discarded because they failed to meet the study criteria. Of the 639 analyzed, 90 were not treated with β-blockers whereas the other 549 were. The latter were further subdivided in high (n = 184) and low (n = 365) β-blockers daily dose group in accordance with an arbitrary cut-off of 25 mg for carvedilol and of 5 mg for bisoprolol. Failure to achieve 80% of the percentage of maximum age predicted peak heart rate (%Max PHR) or of HR reserve (%HRR) constituted chronotropic incompetence. Results: No differences were found in NYHA or pVO2 between patients with and without β-blockers and, similarly, between high and low β-blocker dose groups. Twenty and sixty-nine percent of not β-blocked patients showed chronotropic incompetence according to %Max PHR and %HRR, respectively, whereas this prevalence rose to 61% and 84% in those on β-blocker therapy. Patients taking β-blockers without chronotropic incompetence, as inferable from both %Max PHR and %HRR, showed higher NYHA and pVO2 regardless of drug dose, whereas, in not β-blocked patients, only %HRR revealed a difference in functional capacity. At multivariable analysis, HR increase during exercise ( HR) was the variable most strongly associated to pVO2 (β: 0.572; SE: 0.008; P < 0.0001) and NYHA class (β: −0.499; SE: 0.001; P < 0.0001). Conclusions: HR is a powerful predictor of CHF severity regardless of the presence of β-blocker therapy and of β-blocker daily dose.

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Aims Exercise‐derived parameters, specifically peak exercise oxygen uptake (peak VO2) and minute ventilation/carbon dioxide relationship slope (VE/VCO2 slope), have a pivotal prognostic value in heart failure (HF). It is unknown how the prognostic threshold of peak VO2 and VE/VCO2 slope has changed over the last 20 years in parallel with HF prognosis improvement. Methods and results Data from 6083 HF patients (81% male, age 61 ± 13 years), enrolled in the MECKI score database between 1993 and 2015, were retrospectively analysed. By enrolment year, four groups were generated: group 1 1993–2000 (n = 440), group 2 2001–2005 (n = 1288), group 3 2006–2010 (n = 2368), and group 4 2011–2015 (n = 1987). We compared the 10‐year survival of groups and analysed how the overall risk (cardiovascular death, urgent heart transplantation, or left ventricular assist device implantation) changed over time according to peak VO2 and VE/VCO2 slope and to major clinical and therapeutic variables. At 10 years, a progressively higher survival from group 1 to group 3 was observed, with no further improvement afterwards. A 20% risk for peak VO2 15 mL/min/kg (95% confidence interval 16–13), 9 (11–8), 4 (4–2) and 5 (7–4) was observed in group 1, 2, 3, and 4, respectively, while the VE/VCO2 slope value for a 20% risk was 32 (37–29), 47 (51–43), 59 (64–55), and 57 (63–52), respectively. Conclusions Heart failure prognosis improved over time up to 2010 in a HF population followed by experienced centres. The peak VO2 and VE/VCO2 slope cut‐offs identifying a definite risk progressively decreased and increased over time, respectively. The prognostic threshold of peak VO2 and VE/VCO2 slope must be updated whenever HF prognosis improves.