I47.11

Clinical Causes: Autonomic nervous system imbalance Increased sensitivity of the sinus node to adrenaline Underlying hormonal or metabolic disorders Use of stimulant drugs or medications Structural heart abnormalities Idiopathic factors (unknown causes)

Key Symptoms: Rapid heartbeat (palpitations) Dizziness or lightheadedness Shortness of breath Fatigue Chest discomfort Impaired exercise tolerance Anxiety or a feeling of being overwhelmed Occasional syncope (fainting)

Diagnosis Path: Diagnosing IST involves a combination of medical history, physical examination, and specialized tests. Tests may include: - Electrocardiogram (ECG/EKG): to identify rapid heart rhythms - Holter monitor: 24-48 hour heart rhythm monitoring - Stress testing: to observe heart rate response during exertion - Echocardiogram: to rule out structural heart disease - Blood tests: to check for hormonal or metabolic abnormalities The key feature of IST diagnosis is a persistently elevated resting heart rate, often exceeding 100 beats per minute, not attributable to other causes like fever, anemia, or hyperthyroidism.

Treatment Protocols: Managing Inappropriate Sinus Tachycardia focuses on alleviating symptoms and improving quality of life. Treatment options include: - Lifestyle modifications: reducing caffeine, alcohol, and stimulants; managing stress and improving sleep hygiene - Medications: - Beta-blockers (e.g., metoprolol) to slow heart rate - Calcium channel blockers (e.g., verapamil) - Ivabradine, which selectively reduces heart rate - In some cases, invasive procedures like catheter ablation may be considered if medications are ineffective - Regular follow-up with a cardiologist to monitor heart rhythm and adjust treatment as needed It is important to work closely with healthcare professionals to develop a tailored management plan.