Dysrythmias
Lewis: Medical-Surgical Nursing, 9th Edition
Chapter 36
Nursing Management: Dysrhythmias
KEY POINTS
RHYTHM IDENTIFICATION AND TREATMENT
• The ability to recognize normal and abnormal cardiac rhythms, called dysrhythmias, is an essential nursing skill.
• Four properties of cardiac cells (automaticity, excitability, conductivity, and contractility) enable the conduction system to start an electrical impulse, send it through the cardiac tissue, and stimulate the myocardial tissue to contract.
• The autonomic nervous system plays an important role in the rate of impulse formation, the speed of conduction, and the strength of cardiac contraction. Electrocardiogram Monitoring
• The electrocardiogram (ECG) is a graphic tracing of the electrical impulses produced in the heart.
• ECG waveforms are produced by the movement of charged ions across the semipermeable membranes of myocardial cells.
• There are 12 recording leads in the standard ECG. Changes in a 12-lead ECG may occur with ischemia, infarction, electrolyte imbalance, conduction disturbances, dysrhythmias, or drug toxicity.
• Continuous ECG monitoring is done using one or more leads and based on the patient’s clinical status.
• Telemetry monitoring involves the observation of a patient’s heart rate (HR) and rhythm to help rapidly diagnose dysrhythmias, ischemia, or infarction.
• Normal sinus rhythm starts in the sinoatrial (SA) node and follows the normal conduction pattern of the cardiac cycle. o The P wave represents the depolarization of the atria (passage of an electrical impulse through the atria), causing atrial contraction. o The PR interval represents the time period for the impulse to spread through the atria, atrioventricular (AV) node, bundle of His, and Purkinje fibers. o The QRS complex represents depolarization of the ventricles (ventricular contraction). o The QRS interval represents the time it takes for depolarization. o The ST segment represents the time between ventricular
Chapter 36
Nursing Management: Dysrhythmias
KEY POINTS
RHYTHM IDENTIFICATION AND TREATMENT
• The ability to recognize normal and abnormal cardiac rhythms, called dysrhythmias, is an essential nursing skill.
• Four properties of cardiac cells (automaticity, excitability, conductivity, and contractility) enable the conduction system to start an electrical impulse, send it through the cardiac tissue, and stimulate the myocardial tissue to contract.
• The autonomic nervous system plays an important role in the rate of impulse formation, the speed of conduction, and the strength of cardiac contraction. Electrocardiogram Monitoring
• The electrocardiogram (ECG) is a graphic tracing of the electrical impulses produced in the heart.
• ECG waveforms are produced by the movement of charged ions across the semipermeable membranes of myocardial cells.
• There are 12 recording leads in the standard ECG. Changes in a 12-lead ECG may occur with ischemia, infarction, electrolyte imbalance, conduction disturbances, dysrhythmias, or drug toxicity.
• Continuous ECG monitoring is done using one or more leads and based on the patient’s clinical status.
• Telemetry monitoring involves the observation of a patient’s heart rate (HR) and rhythm to help rapidly diagnose dysrhythmias, ischemia, or infarction.
• Normal sinus rhythm starts in the sinoatrial (SA) node and follows the normal conduction pattern of the cardiac cycle. o The P wave represents the depolarization of the atria (passage of an electrical impulse through the atria), causing atrial contraction. o The PR interval represents the time period for the impulse to spread through the atria, atrioventricular (AV) node, bundle of His, and Purkinje fibers. o The QRS complex represents depolarization of the ventricles (ventricular contraction). o The QRS interval represents the time it takes for depolarization. o The ST segment represents the time between ventricular