Cardiac Dysrhythmias
**Sequence of events for cardiac arrest: Call for help, start CPR**
Normal Conduction Pathway of the heart: ON TEST!
SA node → AV node → Bundle of His → Bundle Branches → Purkinje Fibers
(Ventricles contract at the Purkinje fibers & blood is pumped out of the heart)
Properties of Cardiac Cells:
● Automaticity: Certain cells can generate their own electrical impulses
spontaneously (specific to pacemaker cells)
● Excitability: Ability of ALL cardiac to cells to respond to an electrical impulse
● Conductivity: Ability of ALL cardiac cells to conduct an electrical impulse
● Contractility: Ability of myocardial cells to cause cardiac muscle contraction
Proper 5 Lead ECG Electrode Placement:
White = Right Arm White on Right
Black = Left Arm Snow over Grass
Green = Right Leg Smoke over Fire
Red = Left Leg Chocolate close to the Heart
Brown = Chest
Proper 3 Lead Placement:
-Salt, Pepper, & Ketchup
-White (Heart) Black
Red
Random Info:
● ST Elevation = Heart Attack
○ Could also be Prinzmetal Angina (coronary artery spasm) which is rare (2 out
of 100 cases) and seen more in young men.
● Non ST Elevated Myocardial Infarction (Non-STEMI)
○ Heart attack that does not elevate the ST segment
● When interpreting a sinus rhythm, describe basic underlying rhythm first, then add
additional info: examples:
○ A Fib with RVR → atrial fibrillation with rapid ventricular response
○ NSR with a PVC, NSR with BBB, NSR with 1st degree AV block
● Cardiac monitoring ONLY measures electrical activity of the heart, it does not
guarantee the heart is contracting
Normal Sinus Rhythm: Need to know NORMAL to establish ABNORMAL
**Sequence of events for cardiac arrest: Call for help, start CPR**
Normal Conduction Pathway of the heart: ON TEST!
SA node → AV node → Bundle of His → Bundle Branches → Purkinje Fibers
(Ventricles contract at the Purkinje fibers & blood is pumped out of the heart)
Properties of Cardiac Cells:
● Automaticity: Certain cells can generate their own electrical impulses
spontaneously (specific to pacemaker cells)
● Excitability: Ability of ALL cardiac to cells to respond to an electrical impulse
● Conductivity: Ability of ALL cardiac cells to conduct an electrical impulse
● Contractility: Ability of myocardial cells to cause cardiac muscle contraction
Proper 5 Lead ECG Electrode Placement:
White = Right Arm White on Right
Black = Left Arm Snow over Grass
Green = Right Leg Smoke over Fire
Red = Left Leg Chocolate close to the Heart
Brown = Chest
Proper 3 Lead Placement:
-Salt, Pepper, & Ketchup
-White (Heart) Black
Red
Random Info:
● ST Elevation = Heart Attack
○ Could also be Prinzmetal Angina (coronary artery spasm) which is rare (2 out
of 100 cases) and seen more in young men.
● Non ST Elevated Myocardial Infarction (Non-STEMI)
○ Heart attack that does not elevate the ST segment
● When interpreting a sinus rhythm, describe basic underlying rhythm first, then add
additional info: examples:
○ A Fib with RVR → atrial fibrillation with rapid ventricular response
○ NSR with a PVC, NSR with BBB, NSR with 1st degree AV block
● Cardiac monitoring ONLY measures electrical activity of the heart, it does not
guarantee the heart is contracting
Normal Sinus Rhythm: Need to know NORMAL to establish ABNORMAL
