急性冠心症候群 Acute Coronary Syndrome 心電圖診斷

心電圖診斷 ECG Diagnosis

STEMI ST段上升心肌梗塞

1. 以J point為基準，產生新的連續兩個lead ST波段 ≥0.1 mV(1小格), 例外在V2, V3這兩個lead, 40歲以上男性 ≥0.2 mV(2小格)，40歲以下男性 ≥0.25 mV(2.5小格), 女性不限年齡≥0.15 mV(1.5小格)。

2. 新的LBBB

NSTEMI 非ST段上升心肌梗塞

產生新的連續兩個水平的(horizontal)或下斜的(Down-sloping)lead ST depression ≥ 0.05mV(半小格)，並且或者連續兩個lead T波下降超過1mm(1小格)，合併有一個prominent R wave或R/S ration>1。

梗塞位置 Location

V1-V2 – Anteroseptal
V3-V4 – Anteroapical
V5-V6 – Anterolateral
I, aVL – Lateral
II, III, aVF – Inferior

右冠狀動脈阻塞 RCA occlusion
1. ST depression in lead I
2. ST elevation lead III>II
   Proximal: ST elevation 1mm with positive T wave
   Distal: ST isoelectric with positive T wave in V4R

左冠狀動脈迴旋枝阻塞 LCX occlusion
1. ST elevation in lead II>III
2. ST isoelectric or elevated in lead I
3. ST isoelectric or depressed with negative T wave in T4R

Extension to posterior wall
=> ST depression in precordial lead
Extension to lateral wall
=> ST elevation in lead I, aVL, V5, V6

Ref:

1. Fourth Universal Definition of Myocardial Infarction, 2018 ESC/ACCF/AHA/WHF Expert Consensus Document
2. ECG in emergency Decision Making 2006 2nd Edition

# STEMI and potiential Equivalents 看到這些也要當成可能是STEMI發生

Ref: Electrocardiographic Diagnosis of Life-Threatening STEMI Equivalents: When Every Minute Counts∗ https://www.jacc.org/doi/10.1016/j.jaccas.2019.10.030

理學檢查-心音 Physical Examination-Heart sound

S1：高頻音，注意強度及是否有分裂(Splitting)，在左胸骨側可能會聽到正常的分裂S1心音，S1的大小與心室收縮力有關，在1st degree AV block時也會下降。在RBBB時可在Tricuspid area聽到分裂的S1。

S2：高頻音
Split S2
Physiologic：正常情況下主動脈瓣(A1)比肺動脈(P2)提前關閉，S2在吸氣時因Venous return增加，Pulmonary valve會更晚關閉，S2分裂心音會更明顯，可在Pulmonary area聽到。
Narrow or Single S2：如果吸氣時聽不到Split S2，如肺高壓時(Pulmonary Hypertension)因肺阻力大肺動脈瓣早期收縮 (Early pulmonic valve closure)，或Mild to moderate Aortic Stenosis (Delayed aortic valve closure)。或有一瓣膜消失或大片心室中膈缺損 (VSD)。
Wide S2 split：RBBB
Wide & Fixed S2 split：ASD/RV failure
Paradoxical (Reverse) S2 split：Severe Aortic Stenosis

S3：低頻音，為心房早期收縮射血入心室時產生turbulance之聲音。小於40歲且為運動員或體重瘦的人可能會聽到生理性的S3，大於40歲若聽到則有hemodynamic相關問題，如心室衰竭ventricular failure、左心室擴大等等。

S4：低頻音，為心房晚期收縮射血時，心室舒張異常(LV compliance)造成之聲音，如

心雜音Murmurs： 與S1, S2心音不同，時間上較長。
Loudness (Levine grade)
Gr 1: initially unaware
Gr 2: initially aware
Gr 3: Markable; no thrills
Gr 4: Complte; thrills
Gr 5: edge; thrills
Gr 6: no touch; thrills

Thrill震顫: 觸覺可以感覺得到胸壁震動


Systolic murmurs：S1與S2之間，常見為瓣膜性心臟病或正常生理現象
AS: Midsystolic, at Right base, Erb's point, Apex
HCMP: LLSB, Erb's point
PS/ASD: Left base
MR: Holosystolic, Apex
TR: Holosystolic, LLSB
VSD: Holosystolic, LLSB
Diastolic murmurs：S2與S1之間，常見為瓣膜性心臟病
AR: Early diastolic, at Right base, Erb's point, Apex
MS: Apex

Notes筆記：高頻音用聽診器diaphragm面聽，低頻音用bell面聽，輕放即可。


Ref:
1. Bates' Guide to Physical Examination and History-Taking, 11th edition
2. NTUH teaching