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BASIC ECG. Dr. Gülay ÇİLER ERDAĞ. Dersin amaçları: Ekgnin tanıtılması EKGnin kullanım alanları hakkında bilgi verimesi EKGnin nasıl çekileceği hakkında bilgi verimesi Ekg nin çalışma prensipleri hakkında bilgi verilmesi EKG kağıdı hakında bilgi verilmesi
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BASIC ECG Dr. Gülay ÇİLER ERDAĞ
Dersin amaçları: • Ekgnin tanıtılması • EKGnin kullanım alanları hakkında bilgi verimesi • EKGnin nasıl çekileceği hakkında bilgi verimesi • Ekg nin çalışma prensipleri hakkında bilgi verilmesi • EKG kağıdı hakında bilgi verilmesi • Kalp hızının hesplanması hakkında bilgi verilmesi • Kalp ritminin değerlendirlmesi hakkında bilgi verilmesi • P-r aralığı hesaplanması, p, ors ve r dalgalarının yapısı ve süreleri hakkında bilgi verilmesi • Aks hesaplanması hakkında bilgi verilmesi amaçlanmştır.
Dersin hedefleri: • Öğrencilerin ders sonunda, çocuklarda ne zaman, ne amaçla EKG çekmeleri gerektiği konusunda bilgi sahibi olmaları • Çekilmiş olan bir EKG kağıdına bakarak kalp hızını, Kalp ritmini, kalbin aksını hesaplayabilmeleri, • Varsa p, ors , t dalgalrındaki yapısal bozuklukları farkedebilmeleri, • Varsa kalp bloklarını farkedebilmeleri • Elektrolit bozukluklarına bağlı ortaya çıkabilecek EKG değişikliklerini saptayabilmeleri
Learning Modules • ECG Basics • How to Analyze a Rhythm • Normal Sinus Rhythm • Heart Arrhythmias • Advanced 12-Lead Interpretation
Normal Impulse Conduction Sinoatrial node AV node Bundle of His Bundle Branches Purkinje fibers
Impulse Conduction & the ECG Sinoatrial node AV node Bundle of His Bundle Branches Purkinje fibers
The “PQRST” • P wave - Atrial depolarization • QRS - Ventricular depolarization • T wave - Ventricular repolarization
The PR Interval Atrial depolarization + delay in AV junction (AV node/Bundle of His) (delay allows time for the atria to contract before the ventricles contract)
Atriumların kasılmasıyla oluşan dalga…P dalgası • Ventriküllerin kasılmasıyla oluşan dalga…QRS kompleksi • Ventriküllerin repolarize olmasıyla oluşan dalga…T dalgası • Uyarının sağ atriumdan çıkıp, a-v düğümden iletilmesi için geçen zaman……..P-R aralığı
The ECG Paper • Horizontally • One small box - 0.04 s • One large box - 0.20 s • Vertically • One large box - 0.5 mV
The ECG Paper (cont) 3 sec 3 sec • Every 3 seconds (15 large boxes) is marked by a vertical line. • This helps when calculating the heart rate.
YATAY EKSEN: ZAMAN / DİKEY EKSEN: VOLTAJ • KÜÇÜK KARE = 0.04 sn / BÜYÜK KARE = 0.20 sn (25 mm /sn ) • 10 mm = 1 Mv • İki ince yatay çizgi arası 1 mm, kalın yatay çizgi arası 5 mm
Rhythm Analysis • Step 1: Calculate rate. • Step 2: Determine regularity. • Step 3: Assess the P waves. • Step 4: Determine PR interval. • Step 5: Determine QRS duration.
Step 1: Calculate Rate 3 sec 3 sec • Option 1 • Count the # of R waves in a 6 second rhythm strip, then multiply by 10. • Reminder: all rhythm strips in the Modules are 6 seconds in length. Interpretation? 9 x 10 = 90 bpm
Step 1: Calculate Rate • Option 2 • In routine electrocardiographic practice, the recording speed of the paper is 25 mm. per second. • 1 mm = 0.04 sn • 5 mm= 0.2 sn (1 large division between the heavy lines) • 1 sn=25 mm___1 minute=1500 mm. • Beat: RR interval • 1500/RR(mm)=heart rate Interpretation? • 1500 / 16 = 93
Step 1: Calculate Rate • Option 3: • Find a R wave that lands on a bold line. • Count the # of large boxes to the next R wave. If the second R wave is 1 large box away the rate is 300, 2 boxes - 150, 3 boxes - 100, 4 boxes - 75, etc. (cont) R wave
Step 1: Calculate Rate 300 150 100 75 60 50 • Option 3 (cont) • Memorize the sequence: 300 - 150 - 100 - 75 - 60 - 50 Interpretation? • Approx. 1 box less than 100 = 95 bpm
Step 2: Determine regularity R R • Look at the R-R distances (using a caliper or markings on a pen or paper). • Regular (are they equidistant apart)? Occasionally irregular? Regularly irregular? Irregularly irregular? Interpretation? Regular
Rhythm Summary • Rate 90-95 bpm • Regularity regular • P waves normal • PR interval 0.12 s • QRS duration 0.08 s Interpretation? Normal Sinus Rhythm
NSR Parameters • Rate ......bpm • Regularity regular • P waves normal • PR interval 0.12 - 0.20 s • QRS duration 0.04 - 0.12 s Any deviation from above is sinus tachycardia, sinus bradycardia or an arrhythmia
The SA Node can: fire too slow fire too fast Sinus Bradycardia Sinus Tachycardia SA Node Problems Sinus Tachycardia may be an appropriate response to stress.
Atrial cells can: fire occasionally from a focus fire continuously due to a looping re-entrant circuit Premature Atrial Contractions (PACs) Atrial Flutter Atrial Cell Problems
Atrial Cell Problems Atrial cells can also: • fire continuously from multiple foci or fire continuously due to multiple micro re-entrant “wavelets” • Atrial Fibrillation • Atrial Fibrillation
The AV junction can: fire continuously due to a looping re-entrant circuit block impulses coming from the SA Node Paroxysmal Supraventricular Tachycardia AV Junctional Blocks AV Junctional Problems
Ventricular cells can: fire occasionally from 1 or more foci fire continuously from multiple foci fire continuously due to a looping re-entrant circuit Premature Ventricular Contractions (PVCs) Ventricular Fibrillation Ventricular Tachycardia Ventricular Cell Problems
Rate? 160 bpm • Regularity? regular • P waves? none • PR interval? none • QRS duration? wide (> 0.12 sec) Interpretation? Ventricular Tachycardia
Rate? none • Regularity? irregularly irreg. • P waves? none • PR interval? none • QRS duration? wide, if recognizable Interpretation? Ventricular Fibrillation
Step 3: Assess the P waves • Are there P waves? • Do the P waves all look alike? • Do the P waves occur at a regular rate? • Is there one P wave before each QRS? Interpretation? Normal P waves with 1 P wave for every QRS
P wave • P duration is measured from the onset to the end of the p wave. • The maximal p duration is 0.10 second in normal children(2.5mm) • The mean p amplitude in lead II or any other lead is about 1,5 mmA with a maximum of 3 mm. • Tall waves are an indication of right atrial hypertrophy.
Right atrial enlargement • Take a look at this ECG. What do you notice about the P waves? The P waves are tall, especially in leads II, III and avF. Ouch! They would hurt to sit on!!
Right atrial enlargement • To diagnose RAE you can use the following criteria: • II P > 2.5 mm, or • V1 or V2 P > 1.5 mm > 1 ½ boxes (in height) Remember 1 small box in height = 1 mm > 2 ½ boxes (in height) A cause of RAE is RVH from pulmonary hypertension.
Notched Negative deflection Left atrial enlargement • Take a look at this ECG. What do you notice about the P waves? The P waves in lead II are notched and in lead V1 they have a deep and wide negative component.
Left atrial enlargement • To diagnose LAE you can use the following criteria: • II > 0.04 s (1 box) between notched peaks, or • V1 Neg. deflection > 1 box wide x 1 box deep Normal LAE A common cause of LAE is LVH from hypertension.
Step 4: Determine PR interval • From the onset of the p wave to the begining of the QRS complex • It is the time required for atrial depolarization and the physiologic delay of the impulse in the AV node. • The normal PR interval varies with age and heart rate. • The older the person and the slower the heart rate,the longer is the PR interval.
Step 4: Determine PR interval • Normal: 0.12 - 0.20 seconds. (3 - 5 boxes) Interpretation? 0.12 seconds
Step 5: QRS duration • First negative wave: Q • Positive wave: R • Second negative wave: S • QRS Duration: the time required for ventricular depolarization is short in the young infant and increases with age.
Abnormal QRS amplitude: • Large deflexions: • Ventricular hypertrophy • Ventricular conduction disturbances • Low voltage: • Myocarditis • Pericardial effusions • Chronic constrictive pericarditis • Hypotiroidism
Step 5: QRS duration • Normal: 0.04 - 0.12 seconds. (1 - 3 boxes) Interpretation? 0.08 seconds
Right ventricular hypertrophy • Take a look at this ECG. What do you notice about the axis and QRS complexes over the right ventricle (V1, V2)? There is right axis deviation (negative in I, positive in II) and there are tall R waves in V1, V2.
Right ventricular hypertrophy • Compare the R waves in V1, V2 from a normal ECG and one from a person with RVH. • Notice the R wave is normally small in V1, V2 because the right ventricle does not have a lot of muscle mass. • But in the hypertrophied right ventricle the R wave is tall in V1, V2. Normal RVH
Right ventricular hypertrophy • To diagnose RVH you can use the following criteria: • Right axis deviation, and • V1 R wave > 7mm tall
Left ventricular hypertrophy • Take a look at this ECG. What do you notice about the axis and QRS complexes over the left ventricle (V5, V6) and right ventricle (V1, V2)? The deep S waves seen in the leads over the right ventricle are created because the heart is depolarizing left, superior and posterior (away from leads V1, V2). There is left axis deviation (positive in I, negative in II) and there are tall R waves in V5, V6 and deep S waves in V1, V2.