ECG general info Flashcards
state the indications and purpose of acquiring an ECG
An electrocardiogram (ECG) is a simple test that can be used to check your heart’s rhythm and electrical activity.
ECG is only an investigation and must always be interpreted in light of the clinical findings.
severe cardiac disease may be present despite a normal ECG
lead II is inadequate for diagnosis, 12 lead ECG is essential to make a diagnosis
Demonstrate electrode placement for the standard 12 lead ECG plus V4R and V8
V4R is obtained by placing V4 electrode in the 5th right intercostal space in the midclavicular line.
Leads V7-9 are placed on the posterior chest wall in the following positions:
V7 – Left posterior axillary line, in the same horizontal plane as V6.
V8 – Tip of the left scapula, in the same horizontal plane as V6.
V9 – Left paraspinal region, in the same horizontal plane as V6.
Identify the characteristics of a diagnostic quality ECG.
1 mV (10mm high) reference pulse
One large 5mm x 5mm box represents 200 ms time and 0.5 mV amplitude
One small 1mm x 1mm box represents 40 ms time and 0.1 mV amplitude
paper speed 25mm/sec
Review the diagnostic criteria for STEMI and NSTEMI patients
Central chest pain - crushing, tight
Diaphoresis
Ashen
nausea
vomiting
Describe high risk ACS
Acute coronary syndrome is a term used to describe a range of conditions associated with sudden, reduced blood flow to the heart
characteristics of myocardial ischemia
Pain or discomfort in the upper body, including the arms, left shoulder, back, neck, jaw or stomach
Trouble breathing or feeling short of breath
Sweating or “cold sweat”
Feeling full, indigestion, or a choking feeling (may feel like heartburn)
Nausea or vomiting
Feeling light-headed, dizzy, very weak or anxious
Fast or irregular heartbeat
How to recognise an inferior STEMI
and
pathophysiology
ST elevation in leads II, III and aVF
Progressive development of Q waves in II, III and aVF
Reciprocal ST depression in aVL (± lead I)
pathophysiology:
Inferior STEMI can result from occlusion of all three coronary arteries. 80% of the time its RCA occlusion
RCA occlusion is suggested by:
ST elevation in lead III > lead II
Presence of reciprocal ST depression in lead I
Signs of right ventricular infarction: STE in V1 and V4R
How to recognise an Anterior STEMI
and
pathophysiology
ST segment elevation with Q wave formation in the precordial leads (V1-6) ± the high lateral leads (I and aVL).
Reciprocal ST depression in the inferior leads (mainly III and aVF).
pathophysiology:
LAD or left main coronary artery occlusion
How to recognise an Lateral STEMI
and
pathophysiology
T elevation in the lateral leads (I, aVL, V5-6).
Reciprocal ST depression in the inferior leads (III and aVF).
ST elevation primarily localised to leads I and aVL is referred to as a high lateral STEMI.
pathophysiology:
Three broad categories of lateral infarction:
Anterolateral STEMI due to LAD occlusion.
Inferior-posterior-lateral STEMI due to LCx occlusion.
Isolated lateral infarction due to occlusion of smaller branch arteries such as the D1, OM or ramus intermedius.