VASOVAGAL SYNCOPE and POSTURAL TACHYCARDIA SYNDROME

​Vasovagal syncope is loss of consciousness or fainting from a fall in blood pressure. It is the most common cause of simple fainting. 

 

Most children and young adults have had at least one faint. It can happen in any child but is more common if there is a family history, and more common in girls than in boys. It represents a hyperactive autonomic nervous system that controls heart rate and blood pressure and its response to postural changes. It is most often seen after standing but even after sitting in one posture for a long duration of time, following a sudden change of posture, and in warm or hot environments with poor ventilation. It can be associated with no preceding symptoms or only a slight premonition such as appearing very pale, feeling cold and clammy, or dizzy with hazy vision. Sometimes the exact cause of fainting remains unknown. Vasovagal syncope may be a diagnosis of exclusion.

 

Loss of consciousness leads them to fall to the ground, and once they are lying down, consciousness could return reasonably quickly. Injuries are thankfully infrequent. The colour may take some time to return back to normal.

 

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Postural tachycardia syndrome (PoTS) or postural orthostatic tachycardia syndrome comprises of a cluster of different symptoms dominated by rapid rise in heart rate on standing up from lying down or prolonged sitting position. It may be associated with dizziness or fainting, chest pains, palpitations, shaking of limbs or tremors with pale colour and increased sweating. 

 

Other symptoms that could be part of this condition are tummy pains, diarrhoea or constipation, bloating or feeling sick, blurred vision, blotching of hands and feet with purple skin, weakness and fatigue with inability to do daily activities, sleep disorders and problems with memory and thinking (brain fog).

 

The symptoms can be dramatic, debilitating and life-disrupting. The diagnosis can be made by a good clinical history and examination and ruling out any underlying cardiac condition to cause these symptoms. Hot environment, sudden changes in posture, stress, lack of exercise can all trigger these symptoms. In young teenage girls, symptoms can worsen during periods.

 

PoTS is linked to problems with the autonomic nervous system, an automatic feedback system that adjusts to the changes in the circulation related to events such as change of posture.

 

 

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Syncope of any type can be a distressing symptom for a child or young adult and even more for their parents or carers. It can be a presenting symptom of severe life threatening conditions such as aortic valve stenosis, hypertrophic cardiomyopathy, cardiac arrhythmias or coronary abnormalities.

 

The tests performed by Dr Khambadkone such as echocardiogram, electrocardiogram, 24 hour ECG Holter monitoring, event monitoring, exercise testing, Active Standing Test or tilt testing may help in the diagnosis. Dr Khambadkone will ensure a close collaboration with a Paediatrician or a Paediatric Neurologist if necessary as some forms of epilepsy may present in a similar manner. 

 

 

 

​Once the pattern of vasovagal syncope is recognised, measures to reduce the frequency and severity by avoiding trigger events are necessary. Maintenance of good hydration, controlled change in posture, added salt intake, and medications may help in controlling symptoms. Medications should always be under supervision of medical personnel. There can be a strong element of stress and psychological problems that may contribute to worsening of symptoms and Dr Khambadkone will explore all causes.

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Treatment of PoTS is multipronged with changes in diet, hydration and lifestyle, increased salt intake, supine exercise and rarely medications (beta-blockers, ivabradine, midrodrine, fludrocortisone). PoTS symptoms often resolve after teenage years.