Basic Cardiac Electrophysiology and ECG Concepts

李坤泰 醫師

高雄醫學大學附設中和紀念醫院心臟血管中心

Taiwan Heart Rhythm Society - Allied Professional Education Program2012/09/16Kaohsiung

Ion Channels

Measurement of Action Potential

Action Potential

Rapid depolarization

Early repolarizationPlateau

Final rapid repolarization

Resting membrane potential

Action Potential in Different Cells

Electrical Recording in Heart

Conduction System

Willem Einthoven (Semarang, 21 May 1860 – Leiden, 29 September 1927) was a Dutch doctor and physiologist. He invented the first practical electrocardiogram (ECG or EKG) in 1903 and received the Nobel Prize in Medicine in 1924 for it.[1]

向量

心電圖記錄紙

為何須 12 導極 ?

12 導極

Lead I=L-R Lead II=F-R Lead III=F-L

Einthoven Triangle

Unipolar Leads

胸 前 導

12 導極

波的定義

波的定義• P 波 : 心房去極化 ; 高寬不超過 2.5mm• PR 區間 : 心房去極化到心室去極化開始 ;

包含房室結傳導延遲時間 ;0.12-0.2 秒• QRS 波組 : 心室去極化 ;0.06-0.1 秒• ST 段 : 心室去極化結束到心室再極化開始• T 波 : 心室再極化 • QT 區間 : 心室去極化開始到心室再極化結

束 QTc: QT/√RR; ( 女 > 男 )<0.44 秒

竇性節律 (Sinus Rhythm)

Lead II 為正波

Lead aVR 為負波

心率

口訣 :300,150,100,75,60,50

Calculation of Axis

Calculation of Axis

心軸 (Axis)

-30°

110°

左偏軸

右偏軸

Lead I

Lead aVF

Vector of Ventricular Depolarization

Information from ECG

• Structure abnormality• Arrhythmias• CAD• Electrolyte imbalance• Effects of Medications

心房擴大 (Atrial Enlargement)

右心房擴大 :P 波振幅增大

左心房擴大 :P 波寬度增大

左心室肥厚

左心室肥厚

右心室肥厚

心室肥大

左 , 右束支傳導阻滯

RBBB LBBB

Complete block: QRS>0.12 sec

Serial changes of ECG in AMI

高血鉀

8.6 mEq/L

5.8 mEq/L

低血鉀

1.5 mEq/L

3.7 mEq/L

高 , 低血鈣

QT 延長

低體溫Osborn wave

毛地黃效應

Thanks For Your Attention !!