Safety of surgical masks during physical activity evaluated with graded cycle ergometry test.

BACKGROUND: At the time of the coronavirus disease 2019 (COVID-19) pandemic wearing surgical mask (SM) is recommended for the prevention of contracting or exposing others to airborne transmission of COVID-19. It is somewhat controversial whether wearing SM during exercise affects performance and health status and/or may influence the results. In order to give an answer we planned a prospective, randomized, crossover study to evaluate the effects of wearing a SM or no-SM in 33 (17 male) physically active healthy subjects during a graded exercise cycle ergometry test. METHODS: The two tests were performed in random order in the same subjects. The participants were all tested the same day, after a recovery time of at least of one hour, in order to avoid interferences on physical performances. Arterial oxygen saturation, heart rate and arterial blood pressure were assessed throughout the exercise tests every step of two minutes, at the end of exercise, performed at the same time with and without mask. RESULTS: Wearing SM had no effect on performance, since the duration of cycle ergometry test with SM and without SM median, respectively, was 14.2 (lower-upper quartile 13.9-14.8) versus 14.3 (13.9-15.5) minutes (P=0.094), and median peak power was 150 W (150-180) versus 150 W (120-180) (P=0.754). CONCLUSIONS: When expressed relative to peak exercise performance, no differences were found between wearing or not wearing SM regarding arterial oxygen saturation, or heart rate at any time during the exercise tests. Wearing SM during vigorous exercise had no detrimental effect on cardiovascular parameters, as well as on exercise metrics in all participants. No ventricular repolarization abnormalities and no arrhythmias were reported on the electrocardiograms.

Intraventricular conduction disturbances and paroxysmal atrioventricular block in a young patient with MELAS.

We present the case of a 36-year-old male patient with MELAS (mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes) who developed intraventricular conduction disturbances and syncopal episodes due to a paroxysmal atrioventricular block. This case suggests that in MELAS, as well as in other mithochondriopathies, intraventricular conduction disturbances and atrioventricular block can be features of the disease. In our case, progression toward atrioventricular block was rapid, suggesting that in MELAS patients presenting with worsening conduction system anomalies, pacemaker implantation has to be considered without delay, irrespective of age.

Persistent atrial fibrillation associated with syncope due to orthostatic hypotension: a case report.

A 40-year-old man was referred to our Cardiology Unit because of three syncopal episodes. The ECG showed atrial fibrillation with a mean heart rate of 104 bpm. The patient was unable to maintain the upright position because of marked orthostatic hypotension associated with bradycardia and presyncope. Two days later the patient underwent direct current shock with sinus rhythm restoration. After the procedure both symptoms and orthostatic hypotension disappeared. A tilt test induced marked hypotension and bradycardia only after nitroglycerine. This is the first report of a patient with persistent atrial fibrillation associated with syncope caused by orthostatic hypotension and bradycardia. The patient's clinical features and positive tilt test only after nitroglycerine lead us to hypothesize that the arrhythmia plays a more important role in the etiology of symptoms with respect to autonomic impairment and that the pathophysiological mechanism responsible for these symptoms could be mainly the baroreceptor reflex.