Flashcards in Cardiovascular Management Deck (19):
An electrocardiogram records an electrocardiograph. True/False?
Charge differences during the cardiac cycle creates a dipole which generates an electrical field that is measurable with electrodes. The measured potential difference is greatest when the lead axis is perpendicular to the direction of the dipole. True/False?
Potential difference is greatest when lead axis is parallel to direction of the dipole
Describe the standard limb leads, i.e. where they are aligned
Lead I: RA-LA
Lead II: RA-LL
Lead III: LA-LL
The positive electrode is the recording electrode. What does this mean?
The wave of depolarisation moves towards this electrode
What does the P wave represent? How long is it?
What does the QRS complex represent? How long is it?
Less than 0.10s
What does the T wave represent?
What does the PR interval represent? How long is it?
AV nodal delay
What does the ST segment represent?
(maintained) Ventricular systole
What does the TP interval represent?
What are the 3 augmented limb leads?
aVR, aVL and aVF
Why is the aVR recording inverted on an ECG?
The wave of depolarisation is moving away from this electrode
One large box (5 small squares) on an ECG represents how many seconds?
How do we calculate heart rate on a regular ECG?
300/no. of large boxes between R-R peaks
How do we calculate heart rate on an irregular ECG?
300/no. of QRS peaks in 6 large boxes
What are the main risk factors for CVD?
Lack of physical activity
Hypertriglyceridemia is associated with greater incidence of CVD events than hypercholesterolemia. True/False?
HDL cholesterol tends to be low when triglycerides are high. True/False?