In sinus tachycardia, the heart rate is greater than 100 beats per minute (bpm).
Sinus tachycardia is a type of rapid heart rate that originates in the sinoatrial (SA) node, the heart's natural pacemaker. While a heart rate above 100 bpm can be concerning, it's important to understand the context. It's often a normal response to physiological or psychological stress.
Here's a more detailed breakdown:
- Normal Heart Rate: A normal resting heart rate for adults typically ranges from 60 to 100 bpm.
- Sinus Tachycardia Definition: Sinus tachycardia is diagnosed when the heart rate exceeds 100 bpm and the electrical activity (the rhythm) originates from the SA node. This distinguishes it from other types of rapid heart rhythms (tachycardias) that originate in different parts of the heart.
Here are some common causes of sinus tachycardia:
- Exercise: Physical exertion naturally increases heart rate.
- Stress and Anxiety: Emotional distress triggers the release of adrenaline, which speeds up the heart.
- Fever: An elevated body temperature increases metabolic demands, requiring the heart to pump faster.
- Dehydration: Reduced blood volume forces the heart to work harder to maintain blood pressure.
- Anemia: Low red blood cell count means the heart must pump more blood to deliver adequate oxygen to the body.
- Medical Conditions: Certain conditions like hyperthyroidism, infection, and heart conditions can cause sinus tachycardia.
- Medications and Stimulants: Caffeine, nicotine, alcohol and some medications can increase heart rate.
Important Note: While heart rates slightly above 100 bpm in response to these triggers are often normal, sustained or significantly elevated heart rates (e.g., consistently above 120 bpm at rest) warrant medical evaluation. If experiencing chest pain, shortness of breath, dizziness, or fainting along with a rapid heart rate, seek immediate medical attention.
