Advanced Fetal Monitoring Exam Questions and Answers

What will ST-segment analysis tell you? - - Theoretically, ST-segment analysis of the fetal ECG provides continuous information regarding the ability of the fetal heart to respond to stress in labor by providing information about intracardiac responses to intrapartum hypoxia. - Analysis of the ST segment may permit detection of myocardial ischemia and the fetus' ability to respond to stress prior to peripheral organ and central nervous system damage. When do ST-segment and T-wave changes occur? - with myocardial ischemia, prior to permanent cell damage. What are ST-segment and T-wave elevation indicative of? - fetus at risk of developing hypoxia but still capable of responding against hypoxemia. What are ST-segment and T-wave depression indicative of? - has been associated with the inability of the fetal heart to further respond to hypoxia, indicating that the fetus either had no time to respond or has exhausted compensatory mechanisms. When are fetal ST changes clinically relevant? - when they coincide with category 2 tracings How do you differentiate an irregular heart rate from possible artifact or electronic interference? - - auscultation - ultrasound - echocardiogram - ecg What is an arrhythmia? - - the sporadic, irregular beats typical of the frequent fetal events heard or recorded on the tracing - When there is a disturbance in the heart cell's ability to form and discharge an impulse independently (automaticity & excitability), cardiac rhythm may become tachycardic, bradycardic, or irregular with ectopic beats or premature rhythms such as premature atrial contractions. How are arrythmias categorized? - - based upon the anatomical site of variant impulse formation, conduction, or a combination of both What is the prognosis regarding arryhtmias? - - Most are benign and require no intervention - Most will convert to a normal sinus rhythm after birth Where does the electrical impulse that governs heart rate and rhythm originate? - in the SA Node located in the right atrium Where does the electrical impulse that governs heart rate and rhythm spread from the SA node? - downward to the atrioventricular (AV) node, the bundle of His, & the Purkinje fibers What are some causes of arythmias? - - 99% disappear shortly after birth & pose no long term consequences - Most of the patterns are premature beats - Most are benign - Electrolyte imbalance - Congenital malformations of the heart - Infection - Acidosis - Hydrops fetalis What are characteristics of a dysrhythmia on an FHR strip? - - Irregular but organized pattern - Excursions can be either below or above the baseline and look like "hatch marks" What interventions are required if you see a dysrhythmia? - - If the monitor has a logic switch, turn it to the off position - Evaluate the FHTs with a fetoscope - Evaluate variability between dysrhythmic episodes - Identify causal factors that can contribute to dysrhythmic development (hypoxia, infection) - Notify the collaborative physician or midwife of the findings Characteristics of Supraventricular dysrhythmic patterns? - - Often referred to as "premature beat" patterns - Typically considered benign requiring no intervention other than observation - Tend to disappear in late labor, particularly during contractions, during variable decelerations, or soon after birth - Usually not associated with any underlying cardiac disease - These supraventricular dysrhythmia patterns can be combined with bigeminy, trigeminy, or a combination of both Which occur more commonly, ventricular or Supraventricular dysrhythmic patterns? - Supraventricular