Understanding Resting Sinus Tachycardia

Introduction

Resting sinus tachycardia (RST) is a condition where the heart beats faster than normal (above 100 beats per minute) while the person is at rest. The heart's rhythm originates from the sinoatrial (SA) node, which is normal, but the rate is abnormally high.

Causes of Resting Sinus Tachycardia

Several factors and medical conditions can cause RST:

1. Physiological Causes :

   • Anxiety or stress
   • Fever
   • Physical deconditioning
   • Pain

2. Pathological Causes :

   • Cardiovascular : Heart failure, anemia (low red blood cells), or postural orthostatic tachycardia syndrome (POTS)
   • Endocrine : Hyperthyroidism (overactive thyroid), pheochromocytoma (adrenal tumor)
   • Infections : Sepsis (widespread infection causing body stress)
   • Drug-induced : Caffeine, nicotine, stimulants, certain medications (e.g., beta-agonists)

Symptoms of Resting Sinus Tachycardia

People with RST may experience: - Palpitations (feeling of a fast heartbeat) - Shortness of breath - Dizziness or lightheadedness - Fatigue - Anxiety

Diagnosis

To diagnose RST, a doctor may recommend: - Electrocardiogram (ECG) : To check heart rhythm - Holter Monitoring : Recording heart activity for 24-48 hours - Blood Tests : Checking for anemia, thyroid function, and infections - Echocardiogram : Evaluating heart structure and function - Autonomic Testing : If postural orthostatic tachycardia syndrome (POTS) is suspected

Treatment Strategies

The treatment depends on the underlying cause: 1. Lifestyle Modifications : - Reducing caffeine and alcohol intake - Practicing stress management (e.g., meditation, relaxation techniques) - Improving physical fitness 2. Medications : - Beta-blockers or calcium channel blockers (for heart rate control) - Treating underlying conditions such as hyperthyroidism or infections 3. Special Cases : - If inappropriate sinus tachycardia (IST) is diagnosed (a condition where the heart beats fast without an obvious cause), more specialized treatments may be needed, including ivabradine or ablation procedures.

When to See a Doctor

Seek medical attention if you experience: - Persistent racing heart at rest - Chest pain - Fainting or severe dizziness - Shortness of breath not related to exertion

Understanding and managing RST can significantly improve a person's quality of life. Early diagnosis and appropriate treatment are essential for preventing complications.

Source recommendations

1. American College of Cardiology/American Heart Association (ACC/AHA) Guidelines for the Evaluation and Management of Tachyarrhythmias

1. https://www.ahajournals.org/doi/10.1161/CIR.0000000000000549
2. https://www.acc.org/latest-in-cardiology/ten-points-to-remember/2017/03/07/23/36/2017-acc-aha-hrs-guideline-for-syncope
3. https://www.ahajournals.org/doi/10.1161/cir.0000000000000499
4. https://www.acc.org/latest-in-cardiology/ten-points-to-remember/2018/11/05/15/12/2018-acc-aha-hrs-guideline-on-bradycardia
5. https://pubmed.ncbi.nlm.nih.gov/30586772/

2. European Society of Cardiology (ESC) Guidelines on Cardiac Arrhythmias

1. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Ventricular-Arrhythmias-and-the-Prevention-of-Sudden-Cardiac-Death
2. https://academic.oup.com/eurheartj/article/43/40/3997/6675633
3. https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Supraventricular-Tachycardia
4. https://pubmed.ncbi.nlm.nih.gov/36017572/
5. https://www.ahajournals.org/doi/10.1161/01.cir.0000091380.04100.84

3. Heart Rhythm Society (HRS) Consensus Statements on Sinus Tachycardia

1. https://www.hrsonline.org/guidance/clinical-resources/2015-heart-rhythm-society-expert-consensus-statement-diagnosis-and-treatment-postural-tachycardia
2. https://pubmed.ncbi.nlm.nih.gov/25980576/
3. https://www.hrsonline.org/documents/2015-hrs-pots-ist-vvspdf/download
4. https://pmc.ncbi.nlm.nih.gov/articles/PMC5267948/
5. https://www.heartrhythmjournal.com/article/S1547-5271(23)02246-4/fulltext