About-Cardio
-
We provide our users the most up-to-date and accurate information on the treatment and prevention of cardio pathologies in accordance with current American and European clinical guidelines.
The information provided on this website is for educational purposes only and should not be considered medical advice. Always consult a licensed physician for diagnosis and treatment.
Normal Sinus Rhythm on ECG
Introduction
The electrocardiogram (ECG) is a vital tool in cardiology that helps assess the electrical activity of the heart. The term normal sinus rhythm (NSR) refers to the standard, healthy pattern of electrical impulses originating from the sinoatrial (SA) node, ensuring coordinated and efficient contractions of the heart.
Key Features of Normal Sinus Rhythm on ECG
The following are the primary characteristics of a normal sinus rhythm:
1. Heart Rate
- Typically between 60 and 100 beats per minute (bpm) at rest in adults.
2. Regular Rhythm
- The R-R intervals (the space between two successive R waves) should be consistent.
3. P Wave Characteristics
- Every P wave should be upright in leads I and II and inverted in aVR.
- Each P wave should be followed by a QRS complex, indicating proper atrioventricular (AV) conduction.
4. PR Interval
- A normal PR interval ranges between 120 and 200 milliseconds (ms) (i.e., 0.12–0.20 seconds).
5. QRS Complex
- The width of the QRS complex should be less than 120 ms (i.e., <0.12 seconds), implying normal ventricular conduction.
6. QT Interval
- The QT interval should be appropriate for the heart rate. A normal QTc (corrected QT) should be ≤450 ms in men and ≤460 ms in women.
Clinical Significance of Normal Sinus Rhythm
- Indicates healthy cardiac function and effective conduction of electrical impulses.
- Evaluates arrhythmia risk: If NSR is absent, it may indicate atrial fibrillation, atrial flutter, or other conduction abnormalities.
- Used as a baseline to compare with abnormal ECGs in future assessments.
Conclusion
Recognizing normal sinus rhythm on ECG is fundamental for diagnosing cardiac health and identifying abnormal rhythms. Understanding these characteristics helps differentiate between a physiologic and pathologic heart rate or rhythm.
Source recommendations
1. American Heart Association Guidelines on ECG Interpretation
- https://www.heart.org/en/health-topics/heart-attack/diagnosing-a-heart-attack/electrocardiogram-ecg-or-ekg
- https://www.ahajournals.org/doi/10.1161/circulationaha.108.191095
- https://www.heart.org/-/media/files/affiliates/mwa/kansas-city/kc-cardiac-and-stroke-symposium/2020-event-documents/cardiac-presentations/2-ecg-hockstad.pdf?la=en
- https://www.ahajournals.org/doi/10.1161/circulationaha.108.191098
- https://pubmed.ncbi.nlm.nih.gov/19281932/
2. European Society of Cardiology Guidelines on Arrhythmias
- https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Ventricular-Arrhythmias-and-the-Prevention-of-Sudden-Cardiac-Death
- https://academic.oup.com/eurheartj/article/43/40/3997/6675633
- https://www.escardio.org/Guidelines/Clinical-Practice-Guidelines/Supraventricular-Tachycardia
- https://pubmed.ncbi.nlm.nih.gov/36017572/
- https://www.ahajournals.org/doi/10.1161/01.cir.0000091380.04100.84
-
If you or your loved ones experience any of these symptoms, you should consult a doctor in time. Remember that self-medication can be dangerous, and timely diagnosis will preserve the quality and life expectancy.
The heart is an organ that does not know how to "keep silent" if something goes wrong. Chest pain, shortness of breath, swelling, dizziness, and rhythm disturbances are the symptoms that require our attention. The best prevention of heart disease is careful attention to your health, regular checkups with a doctor, and a healthy lifestyle. Take care of your heart, and it will serve you for many years!
Our advantages:
Best practices from USA, EU and Japan
Our answers to your questions are based on the clinical recommendations of countries with the most developed healthcare systems in the field of cardiology in the USA, the EU and Japan.
Always up-to-date information
On a daily basis, we monitor for you all new scientific research publications in leading scientific journals on medical issues of interest to you.
We monitor all innovations and changes in the field of cardiac disease treatment on a daily basis.
We monitor all innovations and changes in the field of cardiac disease treatment on a daily basis.
Get second opinion
Here you can learn everything that even your doctor may not know about cardiology (if he does not speak English and he does not read 117 leading medical journals on cardiology every month).
The most comprehensive and up-to-date collection of free cardiology materials
Our website contains the most comprehensive and up-to-date collection of free cardiology materials in your country.
Every 3-5 years, half of the scientific approaches to treatment in the field of cardiology are reviewed as a result of specialized scientific discoveries. With us, you don't have to wait these years to learn about the best ways to treat you and your loved ones.
Every 3-5 years, half of the scientific approaches to treatment in the field of cardiology are reviewed as a result of specialized scientific discoveries. With us, you don't have to wait these years to learn about the best ways to treat you and your loved ones.