Electrocardiographic Safety of Daily Hydroxychloroquine 400 mg Plus Azithromycin 250 mg as an Ambulatory Treatment for COVID-19 Patients in Cameroon

Objective: To determine the early electrocardiographic changes in a cohort of ambulatory cameroonian COVID-19 patients treated with hydroxychlo- roquine and Azithromycin. Design: Prospective study. Setting: Treatment centres of the city of Yaounde, Cameroon, from May 7th to 24th 2020. Participants: We enrolled 51 consecutive confirmed COVID-19 on RT-PCR who having mild forms of COVID-19 and treated by hydroxychloroquine 200 mg twice daily during seven #days plus Azithromycin 500 mg the first day and 250 mg the remaining 4 days as per national standard. Main Outcomes Measures: The primary end-point was the change in QTc interval between day 0 (D0), day 3 (D3) and day 7 (D7). Secondary endpoints were changes in all other cardiac electrical conductivity patterns and the occurrence of clinical arrhythmic events during the course of treatment. Results: The population (29 men and 22 women) was aged 39 ± 11 years (range 17 to 61 years). Mean Tisdale score was 3.35 ± 0.48. No significant change from baseline (D0) of QTc was observed at D7 (429 ± 27 ms at D0 versus 396 ± 26 ms at D7;p = 0.27). A reduction of heart rate was observed between the D0 and D7 (75 ± 13 bpm versus 70 ± 13 bpm, p = 0.02) with increased QRS duration between D0 and D7 (95 ± 10 ms versus 102 ± 17 ms, p = 0.004). No symptomatic arrhythmic events occurred during the treatment course. Conclusions: No life-threatening modification of the QT interval was observed in non-severe COVID-19 patients treated ambulatory with hydroxychloroquine and azithromycin. Studies are needed in critical-ill and older patients.

Post-exercise heart rate variability recovery after 800-m endurance run load among Cameroonian adolescent's males

The 800-m(m)run is part of Physical Education classes in Cameroon,after which arrhythmias may occur during recovery.Hence,this study aimed at determining relationship between 800-m run loads on cardiac autonomic recovery among school adolescents.Forty-two male adolescents(aged[17-1]years)performed 800-m.Post-exercise heart rate variability(HRV)was recorded during 5-min(min)(HRV5-min)and 15-min(HRV15-min)in time:Standard deviation of normal to normal(SDNN);Root mean square of successive differences(RMSSD)and frequency domain(LH:Low frequency,HF:High frequency,TP:Total power).Rating of Perceived Exertion(RPE)and blood lactate concentration(BLa)were measured after exercise.In HRV5-min,RPE was associated with SDNN(r=-0.44,p<0.01)and RMSSD(r=-0.38,p<0.05).BLa was correlated with SDNN(r=-0.38,p<0.05)and RMSSD(r=-0.56,p<0.001)in the time-domain,LF(r=-0.64,p<0.001),HF(r=-0.58,p<0.001)and TP(r=-0.61,p<0.001)in frequencydomain.Moreover,RPE was correlated with LF(r=-0.44,p<0.01),TP(r=-0.49,p<0.01)while exercise duration with HF(r=-0.38,p<0.05).In HRV15-min,BLa was correlated with RMSSD(r=-0.53,p<0.001)and SDNN(r=-0.68,p<0.001).RPE was negatively correlated SDNN(r=-0.53,p<0.01)and RMSSD(r=-0.44,p<0.01).BLa was associated with HF(r=-0.55,p<0.001),TP(r=-0.50,p<0.01)and RPE with LF(r=-0.51,p<0.01),HF(r=-0.50,p<0.01),TP(r=-0.49,p<0.01).In addition,exercise duration was negatively linked to HF(r=-0.36,p<0.05).This study outlined that in untrained adolescents an increase of 800-m loads is associated with a slow vagal indexes of HRV during the recovery.