EKG Interpretation PDF

EKG INTERPRETATION Pacemakers of the HEART SA (Sinoatrial) node – Paces the heart at 60- 100 bpm AV (Atrioventricular) node – Bottom portion of atrium that delays the electrical impulse in order for the atria to contract and filling of the ventricles. Back-up pacemaker c...

EKG INTERPRETATION Pacemakers of the HEART SA (Sinoatrial) node – Paces the heart at 60- 100 bpm AV (Atrioventricular) node – Bottom portion of atrium that delays the electrical impulse in order for the atria to contract and filling of the ventricles. Back-up pacemaker cells of 40-60 bpm. Bundle of His – Connects to the AV node. Right Bundle Branch = right ventricle Left Bundle Branch = left ventricle Purkinje Fibers – electrical impulse spread through these to the ventricles causing contraction. Back-up pacemaker cells of 20- 40 bpm. Impulse Conduction and EKG Loading… Basics EKG/ECG Paper Horizontally One small box - 0.04 s One large box - 0.20 s Vertically Loading… One large box - 0.5 mV EKG/ECG Paper 3 sec 3 sec Every 3 seconds (15 large boxes) is marked by a vertical line. This helps when calculating the heart rate. Rhythm Analysis Steps 1. Is there a P wave before every QRS complex? 2. Is it regular (is it evenly spaced apart between the QRS)? 3. What is the rate (count the QRS and multiply by 10)? 4. What is the PR interval (should be 0.12s- 0.20s)? 5. What is the QRS duration (should be 0.6s- 0.10s)? Other Steps With Interpretation 1. QT interval- What does this represent? 2. ST segment- Where should this be? 3. T wave- What would make this abnormal? What is this rhythm? SA Node Problems The SA Node can: fire too slow Sinus Bradycardia fire too fast Sinus Tachycardia Sinus Tachycardia may be an appropriate response to stress. What is this rhythm? Loading… Causes and Treatment of Sinus Bradycardia Causes: Treatment: Valsalva Maneuver Assess patient and determine Vagal stimulation toleration hemodynamically and underlying cause AMI (inferior wall ) Neurological conditions Positive chronotropics (ICP) Administer anticholinergic Administration of drugs (atropine) / parasympathetic drugs parasympathetic blockers Hypothyroidism Pacemaker Therapy What is this rhythm? Causes and Treatment for Sinus Tachycardia Causes: Treatment: Anxiety Determined by underlying cause Stress Assess the patient as to Pain toleration of the increased heart rate Hypovolemia Beta-adrenergic blockers (metoprolol, atenolol) to Stimulants, caffeine reduce the heart rate and myocardial O2 Anemia consumption Heart failure Negative chronotropics to reduce rate Hypotension Carotid massage Valsalva maneuver Hyperthyroidism  Atrial Cell Problems Atrial cells can fire continuously Atrial Fibrillation from multiple foci or Fire continuously Atrial Flutter due to multiple micro re-entrant “wavelets” What is this rhythm? What is this rhythm? Atrial Dysrhythmias Atrial Fibrillation Atrial Flutter No organized No P waves- atrial flutter waves depolarization, (note so no normal P “sawtooth” waves pattern) are (impulses are formed at a not originating rate of 250 -  350 bpm. Atrial Dysrhythmia Treatment Lack of Atrial Kick decreases CO* Increased risk for thrombus formation, treat with anticoagulation* if lasts for > 48 hours Slow ventricular response by increasing AV Block with drugs— beta blockers (lol), Ca channel blockers, digoxin Antiarrhythmics—amiodarone* (Cordarone), Propafenone (Rythmol), sotalol (Betapace), flecainide, procainamide (Pronestyl), ibutilide (Convert), dofetilide (Tikosyn) Elective cardioversion to convert to NSR Radiofrequency catheter ablation Synchronized Cardioversion Therapy for atrial fibrillation/flutter A synchronized circuit in the defibrillator is used to deliver the counter shock during the QRS complex. Patient will receive conscious sedation and be assessed for thrombus with Transesophageal echocardiogram (TEE) FIRST  Ventricular Cell Problems Ventricular cells can: Premature Ventricular Fire occasionally from 1 Contractions (PVCs) or more foci Fire continuously due to Ventricular Tachycardia a looping re-entrant circuit Ventricular Fibrillation Fire continuously from multiple foci What is this rhythm? What is this rhythm? PVCs Originate in the ventricles resulting in wide and bizarre QRS complexes. More than 1 premature beats and look alike – uniform If they look different - multiform One or more ventricular cells are depolarizing and the impulses are abnormally conducting through the ventricles. PVCs- Significance and Treatment PVC falls on the T wave of the preceding beat, the R on T phenomenon occurs—may cause VT or VF Causes: AMI, electrolyte imbalance (< K), MVP, CHF, CAD, caffeine, ETOH, drug therapy Reduce CO, may precipitate angina and CHF, seen after PCI or clot lysis reperfusion arrhythmias Treatment: Assess hemodynamic status Drugs—Beta adrenergic blockers, procainamide, amiodarone Ventricular Conduction Normal Abnormal Signal moves rapidly Signal moves slowly through through the ventricles the ventricles What is this rhythm?  VT Causes, Significance, and Treatment Causes: Same as PVC, ventricular aneurysm, cardiomyopathy, prolongation of QT interval Significance: Severe decrease in CO R/T decreased ventricular filling time and loss of atrial contraction, VT without pulse = VF in Treatment Treatment: With Pulse: Synchronized cardioversion Without Pulse: begin CPR and defibrillate at 360 joules. Give epinephrine for vasoconstriction and amiodarone for arrhythmia. Preventative Treatment: Radiofrequency ablation, Automatic Implantable Cardiac Defibrillator (AICD) What is this rhythm? Loading… VF Treatment Emergency Interventions—begin CPR and institute ACLS measures Defibrillation at 360 joules Drugs—epinephrine, amiodarone Preventative Treatment—Radiofrequency ablation, Automatic Implantable Cardiac Defibrillator (AICD) What is this rhythm? Asystole Treatment NO PULSE NO ELECTRICAL ACTIVITY CALL FOR HELP AND BEGIN CPR ADMINISTER EPINEPHRINE AS QUICKLY AS POSSIBLE. CIRCULATE THE EPINEPHRINE WITH CPR IF AN ELECTRICAL IMPULSE RETURNS, YOU MAY DEFIBRILLATE OR “SHOCK” THE PATIENT.  USE 360 JOULES An ECG alarm goes off. What do you do first? ASSESS THE PATIENT Pacemakers Dual Lead Pacer Defibrillators  Mechanics of Cardiac Cycle Systole is peak pressure in the Cardiac Output arteries, which occurs near the end of the is the total volume of blood pumped by the ventricle per minute. cardiac cycle when the ventricles are cardiac output = heart rate x stroke contracting. volume (CO = HR x SV) What organs are affected by alteration Diastole in cardiac system? is the minimum Preload pressure in the arteries, Preload is the pressure exerted on which occurs near the walls of ventricle at end diastole. beginning of the cardiac Afterload cycle when the ventricles are filled with blood and Afterload is the force against which the ventricles must act in order to resting. eject blood and is largely dependent Ejection Fraction on the arterial blood pressure and