ECG Changes: PVC (Premature Ventricular Contraction)

• On an EKG when you see a really weird beat, know that it is not a sinus beat & it should be considered to be a ventricular beat (it has ventricular origin),
• Not all PVCs look alike
• Vent beats cannot be labeled (PQRST)
• When you have 2 different PVC’s they are multifocal PVC, this is very critical
• If you have 2 points of origin for vent contraction & those signals cross, it is considered ventricular fibrillation, which is quickly fatal
• When every third beat is a ventricular beat, it is called Trigemini
• When every other beat is a ventricular beat, it is called Bigemini
• When every 4^th beat is a ventricular beat, it is called Quadgemini
• When there are 3 or more ventricular beats it is considered a vent rhythm
• When a heart depolarizes in one direction and repolarizes in another, then ischemia is present.
• When the P-wave is half the height of the QRS complex think atrial hypertrophy – P-Pulmonale

• ** When there are more than one hot spot on vent wall, it is called multifocal PVCs.
• ** Most common cause for axis deviation if chamber hypertrophy.
• - With enlargement of left atrium, the P-wave will be long & delayed (time for P-wave is increased. This is called P-Mitrale.
• - With enlargement of right atrium, the P-wave is tall & peaked. This is called P-Pulmonale.
• - Sick Sinus Syndrome when there is a delay b/t beats, due to SA node not firing (Stokes-Adams Attacks, is when this happens & pt. looses consciousness
• - Then nodal beats that were fired by AV node are called escape beats, these are still supraventricular ventricular beats
• - If the escape beats are not supravent (and are caused by the vents) it is not good
• - These pts suffer from vagtonia (increased vegal tone); the treatment in this case is a demand pacemaker.
• - This is almost the same as SA Block (a.k.a. Sinus Arrest)
• - These pts are placed on atropine to inhibit vegal stimulation
• - They probably have subluxations of upper cervical spine

Category: Cardiology Notes