Introduction In 2016 the effectiveness of atropine eyedrops in preventing the progression of myopia in children was confirmed. Atropine produces parasympathetic inhibition because avoids the acetylcholine fixation. Atropine’s main indication is the cardiac stimulation in vagal bradycardia. Its principal cardiovascular side effects are: palpitations, tachycardia and atrial arrhythmias. A paradoxical bradycardia has been documented when atropine is administered at lower doses (<0.1 mg). However, this concept has now been refuted. The last guidelines of the American Heart Association for Cardiopulmonary Resuscitation recommend to eliminate the minimum dose restriction of atropine during emergency intubation (class IIb). The main reluctance of parents to use atropine eyedrops in the control of myopia of their children is the fear of the cardiac effect.

Objective To evaluate the presence of cardiovascular changes after treatment with 0.01% atropine eyedrops administered to reduce the progression of myopia in children.

Material and methods Prospective observational study in 54 patients at the Nens Hospital Foundation in Barcelona (Spain) between 2016–2018. Patients received one drop of atropine 0.01% in each eye (total dose: 0.01 mg) with one minute of tear duct occlusion. Two analyzes were performed: before starting atropine and after 3 months of treatment. The parameters assessed were: somatometric data (weight and height), constants (heart rate and blood pressure), electrocardiographic data (P wave axis, PR segment and arrhythmias) and ultrasound data (left ventricle tele-diastolic diameter).

Results The average age was 10.2 years, with a higher percentage of women (68.5% vs 31.5%). Only one patient presented symptoms of palpitations and there was only one case with arrhythmias. It was an 8 years old girl who presented premature atrial beats. There were no significant differences in the studied variables, with the exception of heart rate. The mean heart rate decreased from 79.4 bpm to 75.3 bpm (p <0.05).

Conclusion The use of atropine 0.01% eyedrops to prevent the progression of childhood myopia is cardiologically safe. Daily use of very low doses of atropine (0.01 mg) over a period of 3 months results in a significant decrease in heart rate.