Unit 4 Module 2P Wave

P wave

Atrial depolarization/systole follows this

QRS complex

ventricular depolarization; atrial repolarization

T wave

ventricular repolarization

Enlarged P wave

greater peak to it, greater width; enlarged atrium

Enlarged Q wave

Myocardial infarction (heart attack); would show up if one had already occurred.

Enlarged R wave

Enlarged ventricle, increase of blood pressure, thickening of the muscular wall, kidneys not releasing excess fluid - increase blood pressure

enlarged T wave

Hyperkalemia - elevated potassium levels. Renal failure is where potassium levels raise which leads to hyperkalemia.

cardiac cycle

systole and diastole of both the atria and ventricles

Average time for a cardiac cycle

0.8 seconds and about 75 BPM

Atrial Systole

pushes blood into ventricle (20ml), end diastolic volume

End diastolic volume (EDV)

“preload” the maximum volume of blood contained within the ventricles prior to ventricular systole (130 ml)

Ventricular systole

increases pressure a the beginning of systole closes the AV valves, isovolumetric contractions, ventricular ejection occurs as the SL valves open

isovolumetric contraction

blood volume within the heart remains the same until SL valves ion (0.05)

Stroke Volume

70 ml of blood is ejected from the ventricles

Relaxation period

both the atria and the ventricles are relaxed, SL valves close, Isovolumetric relaxation, all four valves are closed, volume of blood within the ventricles remains the same

Cardiac Output

volume of blood ejected from the left ventricle each minute (Stroke volume x heart rate)