| What are the bradyarrhythmias? | Sinus Bradycardia, Junctional Rhythm, SA block, AV block |
| Describe the sinus bradycardia. | All appears regular (QRS, PR...) but we have a long PP interval.
There appears to be a problem in SA conduction of impulse (commonly sick sinus syndrome - low battery) |
| Describe the junctional rhythm. | No P wave, electrical impulse is done by the AV node not the SA, QRS normal.
May be caused by hypokalemia, MI, digitalis toxicity... |
| What is the SA block? | Sudden absence of a complete cardiac cycle after being normal with a regular rhythm.
Occurs for athletes, digitalis toxicity, hypokalemia, sick sinus syndrome.
What happens is that the sinus impulse is blocked within the SA node
Irregular and unpredictable |
| How many types of AV blocks are present? | First Degree
Second Degree (mobitz type 1 and type 2)
Third Degree |
| How is the first degree AV block? | It is a delay in conduction, prolonged but constant PR interval
Associated with Carditis, digitalis, beta blockers, ischemia, AV/ junctional disease |
| How is the second degree AV block? | Intermittent conduction failure in AV, blocked by AV node, two mobitz types |
| How is mobitz type 1 AV block? | Classic AV Wenckebach:
PR gradually increases untill there is a pause
RR decreases until the pause occurs then RR after pause is longer than RR before the pause. |
| How is mobitz type 2 AV block? | Sign of bilateral bundle branch block, normal/prolonged PR interval but at some point there is a pause (no QRS after a P) |
| How is the third degree heart block? | Complete dissociation of a rhythm, SA node fires alone and AV fires alone, cause bradycardia (RR interval increases -->45 bpm) |
| How to see a pacemaker on EKG? | Spikes at the Q |
| What is AV dissociation? | non conducted PACs and QRS escapes |
| What are the problems causing arrhythmias? | Problems in • Sinus node
• Atrial cells
• AV junction
• Ventricular cells |
| What SA node problems cause arrhythmias? | Fast firing (sinus tachycardia- may be caused by stress) or slow firing (sinus bradycardia) |
| What atrial cell problems cause arrhythmias? | Premature atrial contractions (if they fire occasionally from a focus)
Atrial flutter (if the fire continuously in a looping circuit) |
| What AV junctional problems cause arrhythmias? | Paroxysmal supraventricular tachycardia by continous looping circuit firing
AV junctional block by blocking impulses from SA node |
| How does premature atrial contraction appear on EKG? | ectopic P waves appearing occasionally with a different contour (biphasic) with a normal sinus rhythm (NSR) |
| What are the supraventricular arrythmias? | • Atrial Fibrillation
• Atrial Flutter
• Paroxysmal Supraventricular Tachycardia |
| What is atrial fibrillation? | It is a deviation from NSR, no normal P wave due to no normal atrial depolarization (impulses are not from sinus node)
chaotic atrial activity
Many P waves appear before conduting a QRS wave
Commonly affects elderly >80 yrs |
| What are the ventricular arrhythmias? | • Ventricular Tachycardia
• Ventricular Fibrillation |
| How is ventricular tachycardia? | Deviation from NSR, impulse originates from ventricles so no P waves and many conseqeutive QRS waves |
| How is ventricular fibrillation? | completely abnormal low QRS with no P wave |
| What are bundle branch blocks? | Stopping of conduction either at right bb or left bb, appears at the QRS complex.
QRS widens and changes morphology |
| How is RBBB? | In V1 and V2 appears as rabbit ears (goes first to the right ventricle starts impulse then blocked so it becomes negative, then left bundle conducts so it goes back to positive) |
| How is LBBB? | Wide and deep negative S wave |
