QTc interval prolongation and life-threatening arrhythmias during hospitalization in patients with COVID-19. Results from a multi-center prospective registry

Background Prolonged QTc interval and life-threatening arrhythmias (LTA) are potential drug induced complications previously reported with antimalarial, antivirals and antibiotics. Objectives To evaluate prevalence and predictors of QTc interval prolongation and incidence of LTA during hospitalization for COVID-19 among patients with normal admission QTc. Methods 110 consecutive patients were enrolled in a multicenter international registry. 12-lead ECG was performed at admission, after 7 and 14 days; QTc values were analyzed. Results Fifteen (14%) patients developed a prolonged-QTc (pQT) after 7 days (mean QTc increase 66±20msec, +16%, p<0.001); these patients were older, had higher basal heart rates, higher rates of paroxysmal atrial fibrillation, lower platelet count. QTc increase was inversely proportional to baseline QTc levels and leukocyte count and directly to basal heart rates(p<0.01).At multivariate stepwise analysis including age, male gender, paroxysmal atrial fibrillation, basal QTc values, basal heart rate and dual antiviral therapy, age(OR 1.06, 95% C.I. 1.00-1.13, p<0.05), basal heart rate(OR 1.07, 95% C.I. 1.02-1.13, p<0.01) and dual antiviral therapy(OR 12.46, 95% C.I. 2.09-74.20, p<0.1) were independent predictors of QT-prolongation.Incidence of LTA during hospitalization was 3.6%. One patient experienced cardiac arrest and three non-sustained ventricular tachycardia. LTAs were recorded after a median of 9 days from hospitalization and were associated with 50% of mortality rate. Conclusions After 7 days of hospitalization, 14% of patients with Covid-19 developed pQTc; age, basal heart rate and dual antiviral therapy were found as independent predictor of pQTc. Life threatening arrhythmias have an incidence of 3.6% and were associated with poor outcome.

Effects of Four Days of Competition Modelling Followed by Six Days of Tapering on Sport Performance in Junior Golfers: a Case Study

Background. The use of competition modelling or tapering to improve sport performance in golf has not been extensively studied. Due to the specific conditions of the main competition, the simulation of competition modelling followed by tapering has been suggested as a means of improving junior golfers’ sport performance. The aim of this study was to determine the most suitable precompetition model and taper for junior golfers to optimize their performance.Methods. Two male golfers (subject A: age 17 years, height 1.75 m, body mass 62 kg, basal heart rate 60 beats⋅min –1 , handicap index 10.1; subject B: age 17 years, height 1.87 m, body mass 68 kg, basal heart rate 60 beats⋅min –1 , handicap index 11.2) participated in this study. Sport performance indicators in golf were recorded using a personal sport performance statistical protocol. Locomotion and physiological demands were recorded using the FRWD W 400 Series (Finland) device. Furthermore, tapering training programmes were recorded.Results. The simulation of four days of competition modelling followed by six days of tapering allowed the subjects to improve their performance; their scoring average at the Lithuanian Amateur Open Golf Championship 2011 was by 6.02% (subject A) and 3.77% (subject B) lower than that for the four-day competition modelling stage.Conclusions. Findings suggest the effectiveness of four days of competition modelling, which allowed the simulation of the specific conditions of the main competition, and also of the practice round held three days before the competition for junior golfers.Keywords: golf, simulation, locomotion, physiological demands, training loads.