ECG Monitoring Techniques PDF

1/9/24, 12:45 AM herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=lqf9HhURQ5RqpgqAkzH2zbusjeLUzRyumZIEGwikvZDA89aMIS3TVE3sojJO… Introduction The electrical impulse that travels through the heart can be viewed using of electrocardiography, the end product of which is an electrocardiogram (...

1/9/24, 12:45 AM herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=lqf9HhURQ5RqpgqAkzH2zbusjeLUzRyumZIEGwikvZDA89aMIS3TVE3sojJO… Introduction The electrical impulse that travels through the heart can be viewed using of electrocardiography, the end product of which is an electrocardiogram (ECG). Each phase of the cardiac cycle is reflected by specific waveforms on the screen of a cardiac monitor or on a strip of ECG graph paper. The ECG is a graphic representation of the electrical currents of the heart. The ECG is obtained by placing disposable electrodes in standard positions on the skin of the chest wall and extremities. Recordings of the electrical current flowing between two electrodes are made on graph paper or displayed on a monitor. Several different recordings can be obtained by using a variety of electrode combinations, called leads. Simply stated, a lead is a specific view of the electrical activity of heart. The standard ECG is composed of 12 leads, or 12 different views, although it is possible to record 15 or 18 leads. Continuous Electrocardiographic Monitoring Continuous ECG monitoring is the standard of care for patients who are at high risk for arrhythmias. This form of cardiac monitoring detects abnormalities in heart rate and rhythm. Many systems have the capacity to monitor for changes in ST segments, which are used to identify the presence of myocardial ischemia or injury. Two types of continuous ECG monitoring techniques are used in health care settings: hardwire cardiac monitoring, found in EDs, critical care units, and progressive care units; and telemetry, found in general nursing care units or outpatient cardiac rehabilitation programs. Hardwire cardiac monitoring and telemetry systems vary in sophistication; however, most systems have the following features in common: •Monitor more than one ECG lead simultaneously. •Monitor ST segments (ST-segment depression is a marker of myocardial ischemia; ST-segment elevation provides evidence of an evolving MI). •Provide graded visual and audible alarms (based on priority, asystole merits the highest grade of alarm). •Interpret and store alarms. •Trend data over time. •Print a copy of rhythms from one or more specific ECG leads over a set time (called a rhythm strip). •Save electronic copies of cardiac rhythms into the electronic health record (EHR). Quality and Safety Nursing Alert Patients placed on continuous ECG monitoring must be informed of its purpose and cautioned that it does not detect shortness of breath, chest pa patients are instructed to report new or worsening symptoms immediately. Hardwire Cardiac Monitoring Hardwire cardiac monitoring is used to continuously observe the heart for arrhythmias and conduction disorders using one or two ECG leads. A real-time ECG is displayed on a bedside monitor and at a central monitoring station. In critical care units, additional components can be added to the bedside monitor to continuously monitor hemodynamic parameters (noninvasive BP, arterial pressures, pulmonary artery pressures), respiratory parameters (respiratory rate, oxygen saturation), and ST segments for myocardial ischemia. The nurse must know the specific indication for each patient’s ECG monitoring. Telemetry In addition to hardwire cardiac monitoring, the ECG can be continuously observed by telemetry—the transmission of radio waves from a battery-operated transmitter to a central bank of monitors. The primary benefit of using telemetry is that the system is wireless, which allows patients to ambulate while one or two ECG leads are monitored. The patient has electrodes placed on the chest with a lead cable that connects to the transmitter. The transmitter can be placed in a disposable pouch and worn around the neck, or simply secured to the patient’s clothing. Most transmitter batteries are changed every 24 to 48 hours. https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=lqf9HhURQ5RqpgqAkzH2zbusjeLUzRyumZIEGwikvZDA89aMIS3TVE3sojJO9aojXmGqF3r… 1/3 1/9/24, 12:45 AM herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=lqf9HhURQ5RqpgqAkzH2zbusjeLUzRyumZIEGwikvZDA89aMIS3TVE3sojJO… Lead Systems The number of electrodes needed for hardwire cardiac monitoring and telemetry is dictated by the lead system used in the clinical setting. Electrodes need to be securely and correctly placed on the chest wall to accurately capture arrhythmias (Sandau, Funk, Auerbach, et al., 2017). There are three-, four-, or five-lead systems available for ECG monitoring. The type of lead system used determines the number of lead options for monitoring. For example, the five-lead system provides up to seven different lead selections. Unlike the other two systems, the five-lead system can monitor the activity of the anterior wall of the left ventricle. The two ECG leads most often selected for continuous ECG monitoring are leads II and V1. Lead II provides the best visualization of atrial depolarization (represented by the P wave). Lead V1 best records ventricular depolarization and is most helpful when monitoring for certain arrhythmias (e.g., premature ventricular contractions, tachycardias, bundle branch blocks). In addition to proper lead and electrode placement, it is important for the nurse to review and customize alarm settings for each patient to reduce false alarms and alarm fatigue (Jepsen, Sendelbach, Ruppel, et al., 2018). Ambulatory Electrocardiography Ambulatory electrocardiography is a form of continuous or intermittent ECG home monitoring. It is used for longer-term monitoring, since some arrhythmias occur intermittently and are difficult to capture with a 12-lead ECG in the office setting. This monitoring can help to identify the etiology of chest pain, syncope or palpitation caused by arrhythmias, detect episodes of myocardial ischemia, evaluate effectiveness of treatment of HF and arrhythmias, and evaluate the functioning of ICDs and pacemakers. Several types of devices are available and are worn either externally or implanted under the skin. The ECG is transmitted to a centralized monitoring station via telephone or wireless technology to a secure Web site (Sampson, 2019). Continuous Monitors Commonly called Holter monitors, these small portable recorders are connected to chest electrodes (number varies based on model used) that record all ECG activity using two or more leads onto a digital memory device. The patient usually wears the recorder for 24 to 48 hours. The patient is also asked to keep a diary to note the date and time of symptoms and activities. The diary is used by the primary provider to correlate symptoms with detected arrhythmias. Once monitoring is completed, the patient returns the device and diary to the primary provider’s office. Data from the digital memory device are then uploaded into a computer for analysis, and rhythms that need further evaluation by the primary provider are identified. Therefore, Holter monitors do not provide real-time ECG recordings or analysis. The effectiveness of this form of monitoring is dependent upon the patient’s adherence with wearing the monitor, keeping an accurate diary, and if an arrhythmia occurred during the monitoring period (Sampson, 2019; Urden et al., 2017). A novel alternative to the use of the Holter monitor is ECG patch monitoring, which uses Bluetooth technology. An ECG patch with adhesive backing is placed over the left pectoral area, eliminating the need for multiple ECG electrodes, wires, and recorders. The patch is single use, waterproof, and easily concealed under clothing. The patient wears the patch for 7 to 14 days and then returns it to the manufacturer for analysis. This device can detect more arrhythmias compared to the Holter monitor since it is worn by the patient for a longer period of time (Sampson, 2019). Intermittent Monitors https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=lqf9HhURQ5RqpgqAkzH2zbusjeLUzRyumZIEGwikvZDA89aMIS3TVE3sojJO9aojXmGqF3r… 2/3 1/9/24, 12:45 AM herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=lqf9HhURQ5RqpgqAkzH2zbusjeLUzRyumZIEGwikvZDA89aMIS3TVE3sojJO… Intermittent cardiac event monitors are devices that can capture arrhythmias when the patient experiences symptoms such as palpitations, dizziness, or lightheadedness. Patients may need to record events for several days to a month. The recorded ECGs are transmitted to the primary provider by telephone or a wireless transmission. The symptom event monitor and external loop recorder are two common forms of external intermittent cardiac event monitors. The symptom event monitor is used to record and store the ECG during only during times when the patient is experiencing symptoms. Patients activate the symptom event monitor by pressing a button for devices that are worn on the wrist or by placing a small handheld device over the chest. The loop recorder, a small battery-operated device, can record and store short periods of ECG activity. The monitor is inserted under the skin or worn on a wrist band. Some loop recorders are programmed to detect bradycardia, tachycardia, and irregular rhythms and do not require patient interaction. Other loop recorders require the patient to activate ECG recordings by pushing a button. The device records the patient’s ECG for a predetermined time before and after the device activation. This is a preferred method over the symptom event monitor because it has more monitoring capabilities. Real-time smart phone monitoring is a novel approach to cardiac event recording. The KardiaMobile® is a small device that connects to a smart phone app. The patient places two fingers on the device which generates a PDF file that can be sent electronically to the provider. Similarly, a patient can place a finger on the digital section of the Apple watch® to generate a rhythm strip. This rhythm is displayed on the watch face and a PDF file is sent to an app on the Apple iPhone® (Sampson, 2019). Cardiac Implantable Electronic Devices Cardiac implantable electronic devices include pacemakers and ICDs. These lifesaving devices are used to manage patients with serious cardiac illnesses. The technology available today allows for remote wireless monitoring of these devices to determine battery life, pacing parameters and therapies, and occurrence of serious atrial and ventricular arrhythmias. A transmitter, which is placed in the patient’s home, sends device data to a secure data repository on a secure Web portal. A unique feature of these implantable devices is that they have programmable alerts that automatically detect and transmit arrhythmias without the need for patient interaction. An implantable cardiac monitor such as the Reveal LINQ™ is another type of electronic device. This small device is implanted subcutaneously under the skin and has a battery life of 3 years. Recordings are triggered when an arrhythmia is detected by the device. Recordings are sent wirelessly via a home monitoring device for expert evaluation. Compared with event recorders described previously, this device offers advantages such as eliminating the patient’s need to change electrodes and wear or carry the monitoring device. This type of monitoring is recommended for patients who have infrequent symptoms or require longer-term ECG monitoring (Sampson, 2019). https://herzing.realizeithome.com/RealizeitApp/Student.aspx?Token=lqf9HhURQ5RqpgqAkzH2zbusjeLUzRyumZIEGwikvZDA89aMIS3TVE3sojJO9aojXmGqF3r… 3/3