ECG and Cardiac Arrhythmias

Question 1

Ventricular Arrhythmias: PVCs

Answer 1

premature beat arising from ventricle

• no P wave & bizarre/wide QRS followed by long pause
• serious PVCs = >6/min
• unifocal = same configuration
• multifocal = different configurations
• Bigeminy = normal sinus impulse followed by PVC
• Trigeminy = PVC after 2 normal beats

Question 2

Ventricular Arrhythmias: Ventricular Tachycardia (VT)

Answer 2

• >3 PVCs occuring sequentially
• 150-200 bpm
• no P wave, wide/bizarre QRS

Question 3

Ventricular Arrhythmias:

Ventricular Fibrillation (VF)

Answer 3

chaotic activity of ventricle originating from multiple focii

• pulseless, emergency situation
• requires CPR, defibrillation, medications
• unable to determine rate
• bizarre activity on ECG w/ no QRS, no effective CO, clinical death within 4-6 minutes

Question 4

Atrial Arrhythmias (Outside SA Node)

ECG signs of A-fib

Rate for Tachycardia, Atrial Flutter and fibrillation

Answer 4

• Rapid, and repetitive firing outside SA node
• P waves are not identifiable, (a-fib) or abnormal
• Atrial tachycardia 140-250
• Atrial Flutter - 250-350
• fibrillation - >300bpm

May occur with a normal heart from caffiene, stress, smoking, alcohol and any type of heart disease

PACs are generally benign, flutter is bad

Question 5

Atrioventricular Blocks

Answer 5

abnormal delays or failure to conduct though normal conduction system

• if ventricular rate is slow, CO decreases

Question 6

ECG Readings

ST depression

ST elevation

inverted T wave

Wide QRS wave

Answer 6

1. ST depression = ischemia downslope 2-3 mm

ST elevation = infarct or pericarditis

inverted T wave = ischemia

Wide QRS wave = bundle branch heart blocks

Question 7

ECG Changes with and Acute MI

Location and change in lead:

Answer 7

• Anterior Wall: V1-V6
• Anteroseptal: V1-V2
• Ateroapical: V3-V4
• Anterolateral: V5-V6, I, aVL
• Lateral wall: I, aVL
• Inferior wall: II, III, aVF
• Posterior wall: not seen typically, V7-9

Question 8

ECG Changes from Drug influence

Digitalis

Quinidine

Beta Blockers

Nitrates

Anti-arrhythmatic agents

Answer 8

• Digitalis - depresses ST, flattens T, shorter QT
• Quinidine - QT lengthens, T flat, QRS long
• Beta Blockers - decrease HR
• Nitrates - increase HR
• Anti-arrhythmatic agents - prolong QRS and QT

Question 9

ECG Changes from Metabolic Influence

Potassium Levels

Calcium Levels

Answer 9

Potassium Levels

• Hyperkalemia - widens QRS, flattens P, “peaked” T
• Hypokalemia - flattens T (or invert), produces U

Calcium Levels

• hypercalcemia - widens QRS, shortens QT interval
• Hypocalcemia - prolongs QT interval

Question 10

Determining Orthostatic Hypertension

Answer 10

Drop in BP that accompanies change from supine to standing

1. Initial HR and BP when pt sitting for >5 minutes
2. move directly into standing and repeat HR, BP immediately, and repeat after 3 minutes

Patient OH = systolic decreased > 20 mmHg or if diastolic decreased >10 mmHg