Young Woman with Postural Tachycardia and Exercise Intolerance

Case at a Glance

A 21-year-old female presenting with chronic tachycardia, exercise intolerance, postural symptoms, and post-prandial dizziness, currently managed with propranolol while awaiting comprehensive cardiac evaluation.

Patient's Story

The patient is a 21-year-old female with a BMI >30 who presents with a 6-7 year history of cardiac symptoms. She reports that her symptoms began during adolescence (ages 14-15) with episodes of morning dizziness accompanied by vomiting, weakness, and palpitations. She initially attributed her rapid heart rate to normal variation. Currently, without her prescribed propranolol 30mg, she experiences significant heart palpitations triggered by physical activity, profound fatigue, and episodes where startling or rapid awakening causes tachycardia accompanied by dizziness, nausea, chest pain, and dyspnea. Post-prandial symptoms include dizziness and difficulty concentrating, particularly after heavy meals. Physical activities such as showering, climbing stairs, and grocery shopping trigger symptom exacerbation. She reports postural instability requiring support when standing, though she denies syncope, lower extremity edema, or significant dyspnea at rest.

Initial Assessment

Physical examination and initial workup revealed normal sinus rhythm with persistent tachycardia on multiple EKGs, with no evidence of atrial fibrillation or other arrhythmias. Emergency department evaluation including comprehensive testing returned normal results. The patient demonstrates significant heart rate elevation from baseline 70-80 bpm to 130 bpm with postural changes and activity, even while on propranolol therapy.

The Diagnostic Journey

The patient has been referred to cardiology for comprehensive evaluation, though appointment availability has delayed definitive assessment. Multiple EKGs have consistently shown normal sinus rhythm with tachycardia. Emergency department workup with standard cardiac and metabolic panels were unremarkable. The temporal relationship between symptoms and postural changes, physical activity, and meals suggests a possible autonomic component to her presentation.

Final Diagnosis

Pending comprehensive cardiac and autonomic evaluation. Differential diagnosis includes postural orthostatic tachycardia syndrome (POTS), inappropriate sinus tachycardia, or other autonomic dysfunction disorders.

Treatment Plan

Currently managed with propranolol 30mg daily for symptom control. Awaiting cardiology consultation for further diagnostic workup including possible tilt table testing, extended cardiac monitoring, and comprehensive autonomic function assessment. Patient counseled on activity modification and symptom monitoring pending specialist evaluation.

Outcome and Follow-up

Patient maintains partial symptom control with current beta-blocker therapy. Cardiology follow-up pending for definitive diagnosis and optimization of treatment plan. Patient advised to continue current medication regimen and seek emergency care for any concerning symptom escalation.