Acute Care Exam 2: Cardiac|2023 LATEST UPDATE|GUARANTEED SUCCESS

What is the 5 step approach to EKG analysis? 1. Heart rate 2. Heart rhythm 3. P wave 4. PR interval 5. QRS complex What is the 6 second method of reading HR? (30 boxes) Denotes a 6 second interval on EKG strip Strip is marked by 3 or 6 second tick marks on the top or bottom of the graph paper Count the number of P waves or R waves within a 6 second strip, and then multiply that number by 10 00:42 01:13 How do you determine atrial rate? Count the number of P waves How do you determine ventricular rate? Count the number of R waves in a QRS complex How do you determine rhythm on EKG? Measure the intervals between R waves (measure from R to R) If the interval between R waves is less than 3 secs, what is the rhythm? Regular If the interval between R waves is greater than 3 secs, what is the rhythm? Irregular What is the P wave? Atrial depolarization First deviation from the isoelectric line Should be rounded and upright P wave represents an impulse from the SA node that pace or fire at regular intervals from same focus What is the PR interval? Measures the time interval from the onset of atrial contraction to onset of ventricular contraction Measured from onset of P wave to the beginning of the QRS complex What is normal PR interval? 0.12-0.20 seconds What is the QRS complex? Ventricular depolarization (contraction) What is the normal interval for QRS complex? 0.04-0.10 seconds 00:01 01:13 What is the isoelectric line? Flat line that occurs: When no electrical activity is occurring When impulses are too weak to be detected Used as a baseline to identify changing electrical movement What is a dysrhythmia? Dysrhythmias are classified according to their site of origin Sites include: SA node (P wave) AV node (PR/PR interval) Junctional tissue (P wave) Ventricular tissue (QRS) What is a ventricular dysrhythmia? Occur when impulses from the sinus and atrial nodes fail Result in abnormal QRS complexes What are the most common ventricular dysrhythmia? Premature ventricular complexes (PVC) Ventricular tachycardia (150 bpm) Ventricular fibrillation Asystole Pulseless Electrical Activity (PEA) What is the QT interval? Total time required for ventricular depolarization and repolarization Varies by age, gender and how fast the pts HR is Factoring patients individual HR→ QTC Measured from the beginning of the Q wave to the end of the T wave What is a normal QT interval? 0.36-0.44 secs What is torsades de pointes? A prolonged QT interval may lead to a unique type of ventricular tachycardia May be caused by Haldol, Amiodarone What is the ST segment? Time of no electrical activity (isoelectric) End of QRS to beginning of T wave Look at height not duration What is ST elevation? Myocardial infarction (cell death) Must be treated before further muscle damage occurs What is done for ST elevation? Get a 12-lead EKG Cardiac enzymes What does ST depression indicate? Myocardial ischemia (cell hypoxemia) Must be treated before further muscle damage occurs What is a T wave? Ventricular repolarization Follows the ST segment Normal Shape: Upright, round, smooth, flat Abnormal Shapes: Peaked, depressed, inverted→ Indicates hyper/hypokalemia What is a premature ventricular contraction (PVC)? Early ventricular contractions May be an early indication of something else to come Shapes: Unifocal (all look alike) or Multifocal (shapes vary) Repetitive rhythms (means more ventricular irritability) 2 PVCs- Couplets Three or more PVCs If become more frequent or in multiples→ be on high alert All components present, but some P-waves lost Wide and Bizarre QRS complex of PVC wide (0.10secs)