Download CARDIOVASCULAR SYSTEM THE HEART

CARDIOVASCULAR SYSTEM
THE HEART
Chapter 18
SINUS RHYTHM
JUNCTIONAL RHYTHM
SA node nonfunctional
SECOND DEGREE HEART BLOCK
AV node blockage
VENTRICULAR FIBRILLATION
Cardiac Cycle
• Diastole
– relaxation
• Systole
– contraction
Cardiac Cycle
Cardiac Output
End-diastolic volume (EDV) - Amount of blood
within the ventricles before they contract.
Ave = 120 ml.
Cardiac Output
Stroke volume (SV) - Amount of blood ejected
from each ventricle in a single beat. Ave = 70 ml.
Cardiac Output
End-systolic volume (ESV) - Amount of blood
remaining in the ventricles after they contract.
Ave = 50 ml.
Cardiac Output
SV = EDV - ESV
SV (ml/beat) = 120 ml/beat - 50 ml/beat
= 70 ml/beat
Cardiac Output
• Cardiac output is the product of the heart
rate and the stroke volume.
CO = HR x SV
CO (ml/min) = 75 beats/min x 70 ml/beat
= 5250 ml/min
Homeostatic Imbalances
Tachycardia - Abnormally
fast heart rate (>100 bpm).
Bradycardia - Abnormally
slow heart rate (<60 bpm).
SINUS TACHYCARDIA
SINUS BRADYCARDIA
VENTRICULAR TACHYCARDIA
Homeostatic Imbalances
Congestive heart failure (CHF) Abnormally low cardiac output due to failure
of either ventricle to eject blood effectively.
Heart attack - When damage or death of
part of the heart occurs as a result of
insufficient blood flow to the myocardium
(ischemia), a heart attack or myocardial
infarction (MI) may result.
Heart disease remains
the leading cause of
death for both women
and men in the United
States.