Ventricular Dysrhythmias

Ventricular dysrhythmias are caused by abnormalities of automatacity or conduction. Ventricular dysrhythmias are usually more serious and life threatening then atrial dysrhythmias. (Black page 1681)

Premature ventricular contractions (PVC)
Disturbances in automaticity

Etiology/RF, of PVCs may be d/t myocardial  hypoxia, hypokalemia, hypocalcemia, acidosis, CAD, CHF, digoxin toxicity, exercise, caffeine, alchohol, nicotine, hypermeatbolic states.
Manifestations: On ECG the PVC occur earlier then the expected beat and followed by a compensatory pause. The QRS duation is greater than 0.12 seconds
Outcomes Interventions:
First of all you wanna treat the cause.
Isolated PVCs are usually not treated, but if the patient becomes symptomatic because decreased cardiac output, then you administer lidocaine or other class 1 antidysrhytmics. (Black, 1682).
Meaning frequent, 2 or more in a row, multifocal PVCs, you then would administer one of the following meds such as Beta blockers-metoprolol, esmolol, Calcium Channel Blockers-verapamil, Electrolytes-magnesium. Antiarryhthmcs-procainamide.

Ventricular Tachycardia (Vtach, VT)


Etiology/RF, VT is alife threatening dysrhythmia that occurs when an irritable ectopic focus in the ventricles takes over as the pacemaker. (Black page 1681). Other risk factors, CAD, CHF, MI with acidosis/hypoxia, cardiomyopathy, dig toxicity, PVC on T wave.
Manifestations: On ECG three or more PVC,s in a row, no P waves, T is part of the QRS
Caridac Output may low or extremely low. The ventricular rate ranges from 100-220 beats/min.
Outcomes Interventions: Cardioversion, lidocaine, amiodarone. AVOID BETA blockers, CALCIUM channel bolckers, and digoxin.
For patients who are unconcious or with really low cardiac ouput (Pusleless VTACH ), you defibrilate.

Vetricular Filbrilation (VFIB,VF)

Reentry of impulses. VFIB is a life threatening dysrhythmia characterized by extremely rapid, erratic, impulse formation an conduction. Causing an abrupt cessation of caridac output.(Black, 1687).

Etiology/RF, hypxemia, hypothermia, contact with high volatge electricity, electrolyte imbalance, drug toxicity, MI, following VTACH.
Manifestations:ECG findings no P waves, QRS complexes, or Twaves
Outcomes Interventions: Must iniate CPR until defribilator is engaged. Defribilate up to three times if needed. (BLack, 1687) Also, epinephrine/vasopressin, precordial thump, mag sulfate, lidocaine, amiodarone, procainamide, sodium bicarb.

Life threatening dysrhythmias
The goal is to stop the dysrhythmia and restore normal sinus rhythm and to identify the cause of dysrhythmia and treat it .Defibrillation is often used to control dysrhythmia.


What are the characteristics of  Ventricular Tachycardia on an ECG strip?
a) No P waves, T waves, or QRS complex
b) QRS duration > 0.12 seconds and beat is often early and followed by a compensatory pause
c) 3 or more PVCs in a row, absent P waves, QRS> 0.12
d) P waves inverted bidirectional, saw tooth
                            answer on top RT side of page.