"-Slows intraventricular conduction by reducing slope of phase 0 action potential.
-Decreases the speed of electrical conduction through the heart muscle, prolongs the electrical phase during which the heart's muscle cells can be electrically stimulated, and prolongs the recovery period during which the heart muscle cells cannot be stimulated.
-Suppresses ventricular ectopy and may be effective when lidocaine has not suppressed it
"Procainamide (Pronestyl) Indications
"-Is acceptable and probably helpful in persistent cardiac arrest due to V-fib.
-Treats A-fib and A-flutter with Wolff-Parkinson-White syndrome (WPW).
-May be useful in suppressing premature ventricular contractions (PVCs) and recurrent V-tach not controlled by lidocaine.
"Procainamide (Pronestyl) Contra-indications
"-Complete AV block
-2nd and 3rd degree heart blocks, unless an electrical pacemaker is operative
-Torsade de pointes (uncommon and distinctive form of polymorphic ventricular tachycardia (VT) characterized by a gradual change in the amplitude and twisting of the QRS complexes around the isoelectric line)
-Induced hypotension after rapid IV administration
-Potent vasodilator and modest negative inotropic effects in patients with dysfunction
"Procainamide (Pronestyl) Dosages
"-17mg/kg is given
-1.2 gm for 70kg patient
-In urgent situations up to 30mg/min can be given until the 17mg/kg is given.
-The maintenance, continuous infusion rate is 1 - 4mg/min
Procainamide (Pronestyl) Suppied in
-10ml vials (100mg/ml)
-2ml vials (500mg/ml)
"Magnesium Sulfate Medication Classifications
"Magnesium Sulfate Mechanisms of Action
"-Magnesium sulfate supplementation may reduce the incidence of post infarct ventricular arrhythmias.
-Precipitate refractory V-fib
-Hinder replenishment of intracellular K+
"Magnesium Sulfate Indications
"Suspected hypomagnesemic state with anterior MI
Torsades de Pointes (treatment of choice)
Severe refractory V-fib
"Magnesium Sulfate Contra-indications
"Administration within two hours of the onset of:
"Magnesium Sulfate Dosages
"For V-fib or V-tach:
-1 - 2gm diluted in 100ml normal saline administered over 1 - 2 minutes
-Loading dose = 1 - 2gm in 50 - 100 ml administered over 5 - 60 minutes
"Adenosine Medication Classifications
"Adenosine Mechanisms of Action
"-May be used to test the heart for coronary artery disease