Telemetry & ECG

Mechanical & Electrical Activity - answer--Correlation between the electrical and mechanical functions of the heart -Electrical activity stimulates the heart to contract -Electrocardiogram (ECG) show both functions -Electrical pulse = action potential Cardiac monitoring is used to: - answer--Diagnose dysrhythmias -Chamber enlargement -Mycoardial ischemia or infarction -Monitor effects of electrolye imbalances of medication administration -Cardiac electrical activity Cardiac electrical activity can be monitored by - answer-ECG. 12 - lead, ambulatory (Holter monitoring), or telemetry For continuous monitoring or telemetry most monitors use 2-4 electrodes. These electrodes create an imaginary line, called a lead, that serves a reference point from which the electrical activity is viewed. A lead is like an eye of a camera - it has a narrow peripheral view, looking only at the electrical activity directly in front of it. - answer- ECG can show - answer-ischemia, infarction, enlarged cardiac chambers, electrolyte imbalances, drug toxicity. Placing Telemetry Electrodes - answer-Clean skin. Clip hair as necessary. Smoke over fire, brown middle. White Right, snow on the grass. Placing EKG Electrodes - answer-Client needs to remain still and breathe normally. Properties of Cardiac Cells: - answer-Conductivity Contractility Automaticity Excitability Refractoriness Conductivity - answer-transmit electrical impulses across cell membranes and from cell to cell Contractility - answer-A/V muscle cells shorten fiber lengths to propel blood forward during contraction Automaticity - answer-Ability of cardiac cells to initiate an impulse (primary pacemaker cells) Excitability - answer-Ability to respond to stimulus and then depolarize Refractoriness - answer-Cells unable to respond to stimulus until recovered from previous stimulus (repolarization) Depolarization - answer-normally negatively charge cells developing a positive charge. Depolarization produces mechanical contractions. Pacemaker function - answer-Although the SA node and AV node ordinarily initiate the pacing of the heart, all of the cells have the capability of doing so. P wave - answer-atrial depolarization (contraction) PR interval - answer-beginning of P wave to end of PR interval: atrial depolarization, AV delay an