16-Year-Old Male with Recurrent Syncope, Convulsions, and Postural Tachycardia

Case at a Glance

A 16-year-old underweight male athlete presents with a 4-5 year history of syncope that has significantly worsened over the past 6 months, now occurring 1-2 times weekly with monthly convulsive episodes. Patient exhibits severe postural tachycardia, exercise intolerance, and autonomic dysfunction symptoms, particularly triggered by heat exposure during showering.

Patient's Story

The patient was previously an active athlete, running 4 miles daily and working with horses for 6 hours. He reports a longstanding history of occasional fainting episodes (4-5 times yearly) that began around age 7. However, symptoms dramatically intensified 6 months ago without any identifiable triggers such as trauma, lifestyle changes, or injuries. Episodes now occur 1-2 times weekly, with convulsive episodes occurring monthly. The patient describes classic presyncope symptoms including visual disturbances and nausea, followed by complete loss of consciousness. Convulsive episodes last 15-45 seconds without incontinence but result in injuries and tongue biting. Most episodes are triggered by postural changes, stair climbing, or showering. Heat exposure during showering causes severe symptoms including heart rates exceeding 180 bpm, visual disturbances, lower extremity color changes, and syncope within 5 minutes.

Initial Assessment

Physical examination revealed a significantly underweight male (BMI 16.5) with known mitral valve prolapse. Vital signs showed marked postural tachycardia with heart rates ranging from 35-200 bpm depending on position and activity. The patient demonstrated concerning autonomic dysfunction with temperature intolerance, color changes in extremities, and exercise intolerance. Notable laboratory finding included unexplored leukopenia on previous blood work.

The Diagnostic Journey

Initial evaluation at urgent care revealed a resting heart rate of 130 bpm, prompting cardiology consultation. A 2-week Holter monitor was placed during which the patient experienced 6-7 syncopal episodes and one convulsive episode. The cardiologist initially reported normal findings and attributed symptoms to anxiety, but subsequently became non-responsive to requests for detailed results. This created a diagnostic impasse as other specialists required cardiac clearance before proceeding with neurological evaluation. The patient's symptoms and heart rate patterns suggested possible Postural Orthostatic Tachycardia Syndrome (POTS), though this diagnosis requires exclusion of other causes and weight optimization.

Final Diagnosis

Suspected Postural Orthostatic Tachycardia Syndrome (POTS) secondary to significant malnutrition and deconditioning, with possible underlying autonomic dysfunction. Differential diagnosis includes neurocardiogenic syncope, cardiac arrhythmias, and seizure disorder requiring further neurological evaluation.

Treatment Plan

Immediate nutritional rehabilitation with goal weight gain to achieve normal BMI was prioritized. Symptomatic management included increased fluid and salt intake, compression garments, and activity modification. Cool water bathing techniques were recommended with safety precautions. Cardiology follow-up was arranged with a different provider to obtain proper Holter monitor interpretation. Pending cardiac clearance, neurology referral was planned for convulsive episodes evaluation. Patient education focused on trigger avoidance and safety measures during episodes.

Outcome and Follow-up

Patient's case highlighted the importance of addressing significant underweight status as a contributing factor to autonomic dysfunction. Communication barriers with initial cardiology provider necessitated care coordination changes. Long-term prognosis depends on successful nutritional rehabilitation and identification of any underlying conditions. Regular monitoring of weight gain, symptom frequency, and functional capacity was established with multidisciplinary team approach including cardiology, neurology, and nutrition services.