EKG

• Cardiac Cycle


  Events associated with one heart beat
• Systole


  Period of contraction
• Diastole


  Period of relaxation
• Blood Pressure


  Pressure in the arteries
• Normal Blood Pressure

  120/80 mm Hg
• Systolic Pressure

  The pressure in the aorta when left ventricle contracts
• Diastolic Pressure

  Heart at rest and lowest pressure in aorta
• Top Number

  Systolic Pressure
• Bottom Number

  Diastolic Pressure
• Conducting System of the Heart

  Sinoatrial Node, Internodal Pathways, Atrioventricular Node, AV Bundle, Purkinje Fibers
• The _____ (pacemaker) generates impulses


  SA Node
• The impulses pause (0.1s) at the _____


  AV Node
• The _____ connects the atria to the ventricles


  AV Bundle
• The bundle branches conduct the impulses through the _____


  Interventricular Septum
• The _____ depolarize the contractile cells of both ventricles

  Purkinje Fibers
• Depolarization

  Contraction
• P-Wave


  Contraction of atria
• QRS Complex


  Contraction of ventricles
• T-Wave

  Heart at rest (Ventricles repolarizing)
• Atrial depolarization, initated by the SA node, causes the

  P-Wave
• With atrial depolarization complete, the impulse is delayed ar the

  AV node
• Ventricular depolarization begins at apex, causing the _____. Atrial repolarization occurs.


  QRS Complex
• Ventricular depolarization is

  Complete
• Ventricular repolarization begins at apex, causing the 


  T-Wave
• Ventricular repolarization is

  Complete
• 60 bpm

  Brachycardia
• 60-100 bpm

  Normal Range
• 100 bpm

  Tachycardia
• _____ sounds heard in 2nd intercostal space at right sternal margin

  Aortic Valve
• _____ sounds heard in 2nd intercostal space at left sternal margin

  Pulmonary Valve
• _____ sounds heard over heart apex (in 5th intercostal space) in line with middle of clavicle

  Mitral Valve
• _____ sounds typically heard in right sternal margin of 5th intercostal space

  Tricuspid Valve
• 1.

  SA Node
• 2.

  Internodal Pathway
• 3.

  AV Node
• 4.

  AV Bundle
• 5.

  Purkinje Fibers
• Normal Sinus Rhythm


  .

  
• Junctional Rhythm


  The SA node is nonfunctional, P-waves are absent and the heart is paced by the AV node at 40-60 bpm

  
• Second-Degree Heart Block


  Some P-waves are not conducted through the AV node, hence more P than QRS waves are seen. In this tracing, the ratio of P-waves to QRS waves is mostly 2:1