Week 12

• Atrial kick: passive filling of the ventricles which makes up about 30% of the blood volume
• Cardiac cells share these 3 features: automaticity, autorhythmicity and autosynchroncity
• Sa node has a bpm of 60 to 100
• Atrial cells have a bpm of 55 to 60
• av node has a bpm of 45 to 50
• his bundle has a bpm of 40 to 45
• bundle branches have a bpm of 40 to 45 which is the same as the bundle of his
• purkinje fibres have a bpm of 35 to 40
• myocardial cells have a bpm of 30 to 35
• ECGs measure voltage/amplitude on the y-axis and measure time on the x-axis
• We use lead 2 to match the direction of electricity in the heart. As electricity heads in that direction, amplitude increases

  
• The negative electrode for the 2 lead is placed over the right arm and the positive electrode is placed over the left leg
• The physiology of V-tach is the rapid depolarization of the ventricles due to chemical imbalance. Could be present with a pulse but there is hemodynamic instability.
• PEA can occur due to the complete loss of blood
• The physiology of PEA is the dissociation between the electrical conduction and the myocardial contraction of the heart
• defibrillation depolarizes a mass of myocardial cells to put them in a resting state so that a pacemaker can take over
• The American heart association sets the standards for CPR and new guidelines are published every 5 years
• Each ventilation should be delivered over a second
• Nobody should touch the PT while the monitor is analyzing
• Medical VSA with hypothermia is a problem because the blood is cold and slow which means it doesn't circulate as well
• For a medical tor: PT must be older than 16, arrest must be unwitnessed by paramedic, must have no rosc after 20 minutes of resus and no shocks delivered
• peri-shock pause is total time without CPR during shock while pre-shock pause is the time from last compression to shock and post-shock pause is the time from shock to CPR
• For re-arrests during transport, pull over and re-analyze/shock then continue to transport without any more stops.
• For a trauma tor: PT must be 16 or older, must have no ROSC, no shocks, have asystole must have no signs of life since extrication or have signs of life with nearest ED being > 30 minutes away or they have PEA with nearest ED being > 30 minutes away