An electrical impulse that passes from cell to cell in the myocardium, stimulating fibers to shorten and causing muscular contraction (systole)
A cardiac arrhythmia characterized by rapid contractions of the atrial myocardium, resulting in an irregular and often rapid ventricular rate
A disturbance or irregularity in the heart rate or rhythm, or both
The action of antiarrhythmic drugs blocking stimulation of beta receptors of the heart by adrenergic neurohormones
The amount of blood leaving the left ventricle with each contraction
A term for quinidine toxicity
The movement of a stimulus passing along the nerve; the positive ions move from outside the cell into the cell, and the negative ions move from inside the cell to outside the cell
A series of digitalis doses given until the drug begins to exert a full therapeutic effect
The amount of blood that the ventricle ejects per beat in relationship to the amount of blood available to eject
Denoted by the area of the initial ventricle dysfunction: Left-side (left ventricular) dysfunction and Right-side (right ventricular) dysfunction; because both sides work together, both sides are affected in heart failure
Marked by reduced blood flow caused by arterial narrowing or blockage or other causes
Left Ventricular Dysfunction
Also called left ventricular systolic dysfunction, the most common form of heart failure
The point at which positive ions on the outside and negative ions on the inside of the cell membrane are in equilibrium
Positive Inotropic Action
The increased force of the contraction of the muscle (myocardium) of the heart through the use of cardiotonic drugs
The development of a new arrhythmia or the worsening of an exsisting arrhythmia caused by an antiarrhythmic drug
The period between transmissions of nerve impulses along a nerve fiber
The movement back to the original state of positive and negative ions after a stimulus passes along the nerve fiber; the positive ions are on the outside and the negative ions on the inside of the nerve cell
List two ways in which cardiotonics act.
- Increasing cardiac output through positive inotropic activity
- Decreasing conduction velocity of AV and SA nodes
List the four factors that influence the dose of cardiotonics that a patient may received.
- Body weight
- Other meds
- Renal function
List the four systems that may show signs of digitalis toxicity.
- GI: anorexia, N/V, diarrhea
- Muscle: weakness
- CNS: dizziness, headache
- Cardiac: arrhythmias
List four conditions in which a cardiotonic is contraindicated.
- Known hypersensitivity
- Ventricular failure or tachycardia
- AV Block
- Digitalis toxicity
List four arrhythmic conditions in which antiarrhythmic drugs could be used.
- PVCs: Premature Ventricular Contractions
- VT: Ventricular Tachycardia
- PACs: Premature Atrial Contractions
- PATs: Paroxysmal Atrial Tachycardia
List three times when a proarrhythmic effect is more likely to occur.
- Excessive dose given
- Given IV
- Pre-exsisting arrhythmia is life threatening
List four conditions in which antiarrhythmic drugs are contraindicated.
- 2nd or 3rd degree AV Block