[Clinical analysis and follow-up study of postural orthostatic tachycardia syndrome in 28 pediatric cases]

Abstract

Objective: Lightheadedness, dizziness, chest discomfort, headache, pallor, palpitation, blurred vision, fatigue, and syncope are main symptoms of postural orthostatic tachycardia syndrome (POTS), but they are also common problems in clinical pediatrics. Besides, most of POTS cases have normal findings in routine examinations on cardiac and central nervous system. Therefore, they are often unable to be correctly diagnosed and treated in time. Since head-up tilt test (HUT) was introduced to diagnose unexplained syncope in children, it was discovered that the most common pattern of unexplained syncope in children was vasovagal syncope. But in the course of the investigation, we and other groups identified a large subgroup of patients who had a less severe form of orthostatic intolerance characterized by postural tachycardia, lightheadedness, dizziness, and chest discomfort, etc. This disorder has become generally known as the POTS, which in children is not rare, but its report was not seen in China so far. The aim of this article is to recognise the clinical pictures of POTS in children and to explore its diagnostic criteria and therapeutic protocol.

Methods: All 28 pediatric patients of POTS who met the diagnostic criteria were selected to be the observation group. Age and sex distribution were observed, and the duration of symptoms, baseline heart rate and blood pressure were also recorded. The frequency of symptoms, the rate of misdiagnosis and the efficiency of therapeutic protocol were also analysed.

Results: Twenty-eight patients were diagnosed as POTS, occupying 31.8% of all unexplained syncope or lightheadedness in children. Eleven were males and 17 females. The ratio of male to female was 1:1.5. All the 28 cases were from 6 to 16 years old, 5 of which were < 10 years and 23 were from 10 to 16 years old, including 10. The duration of symptoms of POTS in children was from 1 month to 6 years. The average was about 13 months, and more than one half were in 6 months. The most common orthostatic symptoms were lightheadedness or dizziness, syncope, chest discomfort, pallor and blurred vision associated with nausea and/or vomiting. During HUT or standing, an increase in heart rate > 35 beats per minute within 10 minutes was the most common finding, and some were associated with > 120 beats per minute within 10 minutes after HUT or standing up. The average time of the occurrence of abnormal responses was about 5 minutes. Especially, we found only 36% of patients were diagnosed with standing up test. Most of them were diagnosed with HUT. POTS in children was misdiagnosed as epilepsy or myocarditis in 43% patients. Multiple treatment protocol including health education and supportive, physical and medical therapy were most helpful in children with POTS.

Conclusion: POTS is commonly seen in school-aged girls. The common symptoms include dizziness, syncope and chest distress. HUT is an important tool in its diagnosis. A comprehensive therapeutic regimen is recommended in the treatment.