Sinus bradycardia

1. Sinus Bradycardia

2. Sinus Bradycardia Sinus rate below 60 beats/minute Regular rhythm Occurs normally during sleep Decreased metabolic demands Occurs normally in a person with a well-conditioned heart Athlete Well-conditioned hearts can maintain a normal stroke volume with less-than-normal effort

3. Sinus Bradycardia How it happens Normal response to a reduced demand for blood flow Vagal simulation increases and sympathetic stimulation decreases Automaticity in the SA node diminishes

4. Sinus Bradycardia A tolerable condition? Most adults can tolerate a sinus bradycardia of 45-59 beats/minute Less tolerant of a rate below 45 beats/minute

5. Sinus Bradycardia Causes Non-cardiac disorders Conditions producing excess vagal stimulation or decreased sympathetic stimulation Cardiac diseases Certain drugs

6. Sinus Bradycardia No symptoms? No problem Symptoms? PROBLEM Prompt attention is critical Can lead to more serious problems Hypotension and dizziness Ventricular tachycardia and ventricular fibrillation

7. Symptomatic Bradycardia If a patient can’t tolerate bradycardia , he may develop these signs and symptoms: Hypotension Cool, clammy skin Altered mental status Dizziness Blurred vision Crackles, dyspnea Chest pain Syncope

8. Symptomatic Bradycardia When to call for help and what to do until help arrives Look at the patient and ask how they are doing Call for help if heart rate is too slow and/or symptomatic Compare it their normal heart rate and rhythm Stay with the patient If the patient is not breathing and does not respond Call code ABCs/CPR

9. Sinus Bradycardia Atrial & ventricular rhythms are regular, as are their rates, except that they’re both under 60 beats/minute

10. Sinus Bradycardia Normal P wave preceding each QRS complex PR interval QRS complex T wave QT interval

11. Sinus Bradycardia P wave rounded, smooth, and upright in lead II, signaling that a sinus impulse has reached the atria

12. Sinus Bradycardia PR interval N ormal indicating that the impulse is following normal conduction pathways 0.12-0.20 seconds

13. Sinus Bradycardia QRS complex Normal duration representing normal ventricular impulse conduction and recovery Less than 0.12 seconds

14. Sinus Bradycardia T wave Upright in lead II, confirming that normal repolarization has taken place

15. Sinus Bradycardia QT interval Within normal limits 0.36 to 0.44 seconds