Module 6: Cardiovascular Flashcards Preview

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Flashcards in Module 6: Cardiovascular Deck (237)
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211

aVR

Negative Terminal: Left Arm; Left Leg
Postitive Terminal: Right Arm

212

aVL

Negative Terminal: Right Arm; Left Leg
Positive Terminal: Left Arm

213

aVF

Negative Terminal: Left Arm; Right Arm
Positive Terminal: Left Leg

214

Anatomical Perspective of ECG Leads: V1, V2

Septal wall

215

Anatomical Perspective of ECG Leads: V3, V4

Anterior wall

216

Anatomical Perspective of ECG Leads: II, III, aVF

Inferior wall

217

Anatomical Perspective of ECG Leads: I, aVL, V5, V6

Lateral wall

218

__ does NOT face the epicardial wall of the heart,
so it is NOT useful for assessing ischemia

aVR

219

- along sternal borders
- supplied by left anterior descending artery

Septal Wall

220

• left anterior chest
• supplied by left anterior descending artery

Anterior Wall

221

- inferior view from leg
- supplied by:
•right coronary artery (90%)
•left circumflex artery (10%)

Inferior Wall

222

- view from left arm
- supplied by left circumflex artery

Lateral Wall

223

ECG Paper

5 Large boxes = 1.0 second
1 Large Box = 0.2 seconds
Small Box = 0.04 seconds

224

Standardization of Normal Values

Heart Rate 60 – 100 beats/min
–Bradycardia 100 beats/min

PR interval 0.16 sec (NR: 0.12 – 0.20)
QRS duration

225

Determination of Heart Rate

- Rule of 300
- Mathematical Formulae
- Six Second Strip Method

226

Rule of 300

- Always remember! 300-150-100-75-60-50
- Count the number of big boxes between two R waves
1 large square = 300/min
2 large squares = 150/min
3 large squares = 100/min
4 large squares = 75/min
5 large squares = 60/min

227

Mathematical Formulae: using large boxes between R-R

Heart rate = 300/number of large boxes between R-R

228

Mathematical Formulae: using small boxes between R-R

Heart rate = 1500/number of large boxes between R-R

229

- If there are no P waves, count the number of R waves in a 6-second strip and multiply this number by 10 to get the heart rate

Six Second Strip Method

230

Determination of Rhythm

Are normal P waves present?
–NORMAL: Yes, P waves are present.

Are QRS complexes narrow (0.12s)?
–NORMAL: The QRS complexes are narrow.

What is the relationship between the P waves and the QRS complexes?
–NORMAL: There is one P wave for every QRS complex.

Is the rhythm regular or irregular?
–NORMAL: The rhythm is regular

231

Types of Rhythms

SINUS RHYTHM
–Originates from the sinoatrial node
–Intrinsic rate of 60-100 beats/minute

NODAL RHYTHM
–Originates from the AV node
–Intrinsic rate of 40-60 beats/minute

VENTRICULAR RHYTHM
–Originates from the Purkinje fibers
–Intrinsic rate of 20-40 beats/minute

232

Determination of Axis

- Vectorial Analysis
- Thumbs Method
- Isoelectric Lead Method
- Mathematical Formula

233

(Thumbs Method)

Lead I: Up
avF: Up

Normal Axis

234

(Thumbs Method)

Lead I: Up
avF: Down

Left axis deviation

235

(Thumbs Method)

Lead I: Down
avF: Up

Right axis deviation

236

(Thumbs Method)

Lead I: Down
avF: Down

Extreme right axis deviation

237

- Isoelectric lead refers to lead with equal forces in the positive and negative direction
- Often this is the lead with the smallest QRS
- The QRS axis is perpendicular to the orientation of the isoelectric lead

Isoelectric Lead Method