Block IV - Advanced ECG Diagnostic PDF

Advanced ECG Diagnostic Block IV Prepared by Khulud Al-Johani www.ax.qgiecois Ambulatory ECG monitoring In contrast to the standard electrocardiogram (ECG), which provides a brief sample of cardiac electrical activity over 10 seconds, ambulatory ECG monitoring provides a view...

Advanced ECG Diagnostic Block IV Prepared by Khulud Al-Johani www.ax.qgiecois Ambulatory ECG monitoring In contrast to the standard electrocardiogram (ECG), which provides a brief sample of cardiac electrical activity over 10 seconds, ambulatory ECG monitoring provides a view of ECG data over an extended period of time, thereby permitting evaluation of dynamic and transient cardiac electrical phenomena. The most common ambulatory ECG application is in the diagnosis and assessment of cardiac arrhythmias or conduction abnormalities (symptomatic or asymptomatic) or the presence of potential arrhythmias (such as in patients with syncope or presyncope); however, ambulatory ECG also has a role in stratification of certain cardiomyopathies, in assessing the effectiveness of arrhythmia therapy, and in the evaluation of silent ischemia. µ c g The three major types of ECG are: Resting ECG – lie down for this type of ECG. No movement is allowed during the test, as electrical impulses from other muscles can interfere with the test. This type of ECG usually takes five to 10 minutes. Ambulatory ECG – for an ambulatory ECG will wear a portable recording device for at least 24 hours. free to move around normally while the device is attached. A doctor may arrange this type of ECG if he have symptoms that are intermittent (stop-start) which may not show up on a resting ECG. The doctor may also recommend an ambulatory ECG if he is recovering from heart attack, to ensure the heart is working properly. may be asked to write down or record any symptoms experience while wearing the device, including when they occur. Exercise stress test/stress test – this type of ECG helps the doctor to see how well the heart is working during physical activity. This type of ECG takes about 15 to 30 minutes to complete. A stress test can also involve medicines, to understand their effects on the heart.  angulatory There are 2 categories of AECG recorders: continuous recorders, typically used for 24 to 48 hours to investigate symptoms and ECG events that are likely to occur within that time frame, and intermittent recorders, which may be used for long periods of time (weeks to months) to provide briefer, intermittent recordings for investigating events that occur infrequently.  a am i.ka.iq Indications for ambulatory ECG Unexplained syncope, near syncope, or dizziness. in Unexplained recurrent palpitation. Evaluation of patients with unexplained symptoms. TYPES OF AMBULATORY ECG MONITORING q Continuous ambulatory ECG (Holter) monitor. q Event (loop) monitor. q Patch monitor. q Mobile cardiac outpatient telemetry (MCOT). q Insertable cardiac monitor. q Permanent pacemakers and implantable cardioverter- defibrillators q Commercially available wearable heart rhythm monitors OUR APPROACH TO CHOOSING AN AMBULATORY ECG MONITORING STRATEGY The approach to choosing an ambulatory ECG monitoring strategy depends i on the indication for the test in addition to the frequency and duration of symptoms. 2 3 f is Continuous ambulatory ECG (Holter) monitor continuous ambulatory ECG system, generally referred to as a Holter monitor, is most commonly performed for patients with frequent (ie, daily or near daily) symptoms of palpitations. Continuous ambulatory ECG (Holter) monitoring includes a continuous recording of all ECG data for a period of 24 or 48 hours. This technology uses a small, lightweight, battery operated recorder that typically records two or three channels of ECG data (although 12-lead monitors are also available) from electrodes placed on the patient's chest. A typical Holter monitor report includes the following information o Total heart beats o Average heart rate o Maximum and minimum heart rates o Number of premature beats (supraventricular and ventricular) o Episodes of tachyarrhythmia and the etiology of the arrhythmias (eg, supraventricular or ventricular) o Longest R-R interval and any pauses greater than three seconds and etiology of the pauses (eg, sinus pauses versus AV block) e o ST segment changes o Patient-reported symptoms and any associated ECG findings o Representative samples of ECG tracings (eg, hourly samples) Arrhythmias that are warning Frequent and complex atrial and ventricular rhythm disturbances. Second-degree AV block type II. Third-degree AV block. Sinus pauses longer than 2.5 seconds. Marked bradycardia during waking hours. Tachyarrhythmias. Patient preparation Prepare Skin for the Electrodes: Proper preparation of the areas of the chest where the electrodes will attach is essential for good ECG recordings. Always Wear the Monitor: Patient have to wear the monitor and keep it turned on 24 hours a day, every day, for the entire length of prescribed procedure, during all normal daily activities except those that involve water. Do not get any part of the monitor wet. Record Activities in a Diary: This will help to understand the activities surrounding the arrhythmia, which can lead to a diagnosis on what causes them. Avoid Things that Create Interference: This includes magnets, microwaves, electric blankets , and cell phones. Follow Instructions: It’s very important to follow the instructions provided in the monitor ’s user guide.  Event (loop) monitor Referred to as loop monitors because the recording device continuously looped its recording tape, most commonly used for patients with less frequent (ie, weekly to monthly) symptoms of palpitations, presyncope, or syncope. Similarly to Holter monitors, event monitors use a small, lightweight, battery operated recorder. activated by patient trigger when symptoms arise. Post Event Monitoring devices are generally small, lightweight devices that can be placed on the patient’s chest upon the onset of symptoms. The patient's rhythm is I stored for a specified amount of time after recording begins (eg, 30 to 150 seconds). Event/Loop Recorders are devices that constantly record for a pre-specified period, but do not save the data until they are triggered to do so by the patient pushing an event button. The device will record and save the patient's rhythm for a pre-specified amount of time before and after activation of the device (eg, 30 seconds prior to and 60 seconds after the event). Auto-triggered Event Recorders are more advanced devices. In addition to recording and saving symptomatic patient-triggered events, these devices have auto-detect features that will capture asymptomatic arrhythmias based on detection algorithms (eg, atrial fibrillation events or bradycardia events).  Patch monitor are all-in-one small adhesive devices that do not require separate leads, wires, or battery packs, This makes them more convenient and less obtrusive than traditional Holter or event monitors. Patch monitors are capable of continuously recording an ECG for up to 14 days, although only a single lead is recorded Patch monitor report — A typical patch monitor report includes the following information : Average heart rate Maximum and minimum heart rates Number of premature beats (supraventricular and ventricular) Episodes of tachyarrhythmia and the etiology of the arrhythmias (eg, supraventricular or ventricular) Longest R-R interval and any pauses greater than three seconds and etiology of the pauses (eg, sinus pauses versus AV block) ECG tracings for each patient-triggered (or auto-triggered) event  Mobile cardiac outpatient telemetry (MCOT) MCOT can be worn for up to 30 days. Traditionally, a three-lead sensor transmits ECG telemetry data to a small portable monitor. The monitor transmits the ECG information to a monitoring center via built-in cell phone technology. The device can also be triggered to record symptomatic events by the patient or can be triggered automatically in response to programmed settings. Algorithms for automatic arrhythmia detection analyze every heart beat and are based on rate, rhythm irregularity, P wave analysis, and QRS morphology. A single lead MCOT patch monitor is also available. As events occur, patient ECG data is automatically transmitted to the monitoring center for analysis. Certified technicians review the data and a daily report and service-summary report is made available for online review (or by fax).Immediate reports for potentially life-threatening arrhythmias can also be created and physicians are alerted to promptly review these episodes.. v MCOT has been shown to detect significantly more arrhythmias than standard patient triggered loop recorders and has been shown to be effective in diagnosing AF after cryptogenic stroke. Daily reports on burden of arrhythmia (such as AF) are provided and MCOT can be useful to assess for possible nocturnal arrhythmias such as those associated with sleep apnea. v Notably, prescribing physicians should be aware that MCOT can be more expensive than standard event monitoring A typical MCOT report includes the following information: Daily and service-summary reports on heart rate and rhythm Daily and service-summary reports on classification, duration, and frequency of arrhythmic events ECG tracings for each patient-triggered (or auto-triggered) event Technician's interpretation of the tracing Reported symptoms and their duration Insertable cardiac monitor is a subcutaneous monitoring device These devices are typically implanted in the left pectoral region. the ability to monitor for cardiac arrhythmias for prolonged periods of months to years. Implantation of the ICM is typically performed as an outpatient procedure using local anesthesia with few associated risks. A typical ICM report includes the following information : Heart rate histograms, heart rate variability, and patient activity data Episode lists including classifications, frequency, and duration of arrhythmic events Single lead ECG tracings for each patient-triggered (or auto-triggered) event used as a continuous monitoring devices, as these systems have built-in algorithms for the recognition of various arrhythmias (such as AF or VT) The devices can be interrogated to obtain data about arrhythmia frequency, duration, and atrial and ventricular rates. In addition, intracardiac ECGs meeting detection criteria can be recorded and stored for review. Permanent pacemaker implanted device that provides electrical stimuli, thereby causing cardiac contraction when intrinsic myocardial electrical activity is inappropriately slow or absent. Indications Symptomatic Bradycardia with no reversible cause CHB or Mobitz 2 (Regardless of symptoms) Sinus pause more than 3 seconds with symptoms or more than 5 seconds without symptoms Carotid hypersensitive syndrome Chronotropic incompetence. Sick sinus syndrome. Atrial and ventricular pacing can be seen on the electrocardiogram (ECG) as a pacing stimulus (spike) followed by a P wave or QRS complex, respectively. The ECG has the ability to show normal and abnormal pacemaker function. 0 0 0 specialized device designed to directly treat many dysrhythmias  Commercially available wearable heart rhythm monitors These devices can be useful in the diagnosis of arrhythmia in certain patients. Many of these technologies come in the form of electronic wristbands and smartwatches. Optical sensors integrated into these devices use photoplethysmography to measure pulse rate DIAGNOSTIC EFFICACY The ECG rhythm recorded using any ambulatory ECG monitoring modality must be correlated with the simultaneous occurrence of suggestive symptoms. Without this correlation in many cases, the detected rhythm abnormality is less likely to be clinically important. Bradycardia and sinus pauses are particularly common at night while the patient is asleep, as a result of enhanced vagal tone. Thus, the occurrence of such arrhythmias does not necessarily establish a causal mechanism for a transient disturbance in consciousness or for other symptoms. Ambulatory ECG monitoring yields other potentially useful information regarding arrhythmias, including: Quantifying the number of ectopic morphologies (if multiple) and allowing qualitatively visual analysis of the different morphologies. Providing information regarding the onset and resolution of tachyarrhythmias and bradyarrhythmias. Providing information on a variety of arrhythmia characteristics such as coupling interval, rate dependence, and changes in QT interval. FOLLOW-UP AFTER AMBULATORY ECG MONITORING The patient had symptoms with corresponding ECG abnormalities – Such patients should be treated appropriately and, do not require additional ambulatory ECG monitoring for diagnostic purposes (although additional monitoring to assess the efficacy of therapy might be indicated). The patient had symptoms without corresponding ECG abnormalities – assuming that the monitor was functioning properly and the available ECG data are interpretable, the diagnosis is likely non-cardiac and there is generally no need for additional ambulatory ECG monitoring. The patient had no symptoms and no ECG abnormalities during the monitoring period – The decision to pursue additional testing following a period of ambulatory ECG monitoring depends on the potential severity of the clinical conditions.