Cardiac Section

Premature Ventricular Contraction.

Three or more successive PVCs are called nonsustained ventricular tachycardia.

These can be common

Rapid atrial depolarization

premature atrial contraction

when atrium fires impulse before the next one comes, and is usually followed by a pause. There are rarely other symptoms associated with this. Can be caused by stress or inflammation

Supraventrical Tachycardia

• may be normal
• P waves may not be visible
• PSVT = intermittent

• The most common dysrhthmia
• Atrium is depolarized randomly

pulmonary embolis

0.04-0.1

0.12-0.2

• Are They present?
• DO they occur regularly?
• Is there one P wave for each QRS?
• Are they smooth, rounded, and upright?
• Are they all similar looking?

• Determine HR
• Determine Heart Rhythm
• Analyze P waves
• Measure PR interval
• Measure QRS duration
• interpret rhythm

• pretty normal
• results from changes in intrathoracic pressure while breathing
• PP and RR intervals vary by more than 0.12 seconds

• 300
• 150
• 100
• 75
• 60
• 50
• 43
• 37
• 33
• 30

• total time for ventricals to depolarize and repolarize
• QRS-Twave

late ventricular repolarization

represents ventricular repolarization

early ventricular repolarization

represents the junction where QRS ends and ST starts

represents necrosis

ventricular septal depolarization

ventricular depolarization

• measured from P wave to end of PR segment
• normally measures 0.12 to 0.2 seconds

• isoel line
• when impulse is going through AV node

atrial depolarization