Cvs module phase II MBBS 2007- 2008 CARDIAC CYCLE PHYSIOLOGY CARDIOVASCULAR MODULE PHASE II 2007-2008

cvs module phase II MBBS 2007-2008

CARDIAC CYCLE

PHYSIOLOGY

CARDIOVASCULAR MODULE

PHASE II 2007-2008


INSTRUCTOR INFORMATIONDr AZRA KIRMANIASSISTANT PROFESSORDEPARTMENT OF PHYSIOLOGYROOM NO 951/1FIRST FLOOR BUILDING 9EXT- 24306MOBIL- 0501639346, RESIDENCE - 6022433



Events of the cardiac cycle at a heart rate of 75 beats/min

Ventricular Diastole 0.5 seconds

Ventricular Systole 0.3 seconds

Atrial systole 0.1 secondAtrial Systole 0.7 seconds


Late Diastole


Atrial Systole


Atrial Systole


ATRIAL SYSTOLEECG


ATRIAL SYSTOLEHeart Sounds


• Atrial systole contributes 30% 0f ventricular filling.

• The end diastolic ventricular volume is 130ml.


Isovolumetric ventricular contraction


ISOVOLUMETRIC CONTRACTIONECG


ISOVOLUMETRIC CONTRACTIONHeart Sounds


Ventricular Ejection


RAPID EJECTIONPressures & Volumes


RAPID EJECTIONECG


RAPID EJECTIONHeart Sounds


REDUCED EJECTION

Late in systole, the aortic pressure actually exceeds the ventricular, but for a short period momentum keeps the blood moving forward.


REDUCED EJECTIONHeart Sounds


PROTODIASTOLE

• Once the ventricular muscle is fully contracted, the already falling ventricular pressures drop more rapidly. This is the period of protodiastole. It lasts about 0.04 s. It ends when the momentum of the ejected blood is overcome and the aortic and pulmonary valves close, setting up transient vibrations in the blood and blood vessel walls.


• The amount of blood ejected by each ventricle per stroke at rest is 70-90 mL.

• The end-diastolic ventricular volume is about 130 mL.

• Thus, about 50 mL of blood remains in each ventricle at the end of systole (end-systolic ventricular volume).

• The ejection fraction, the percent of the end-diastolic ventricular volume that is ejected with each stroke, is about 65%.

• The ejection fraction is a valuable index of ventricular function.


Isovolumetric ventricular relaxation


ISOVOLUMETRIC RELAXATION


ISOVOLUMETRIC RELAXATIONECG


ISOVOLUMETRIC RELAXATIONHeart Sounds


RAPID VENTRICULAR FILLINGHeart


RAPID VENTRICULAR FILLING Pressures & Volumes


RAPID VENTRICULAR FILLING ECG


RAPID VENTRICULAR FILLINGHeart Sounds


REDUCED VENTRICULAR FILLING Pressures & Volumes


REDUCED VENTRICULAR FILLING ECG


REDUCED VENTRICULAR FILLING Heart Sounds



cardiac cycle.swf


Events of the cardiac cycle at a heart rate of 75 beats/min

• 1, atrial systole;

• 2, isovolumetric ventricular contraction;

• 3, ventricular ejection; – Rapid ejection– Slow ejection– Protodiastole

• 4, isovolumetric ventricular relaxation;

• 5, ventricular filling.


Note that late in systole, aortic pressure actually exceeds leftventricular pressure. However, the momentum of the blood keeps it flowing out

of the ventricle for a short period.




Right Ventricular & Pulmonary Arterial Pressure





Pressure Volume Relationship

Documents

Cvs module phase II MBBS 2007- 2008 CARDIAC CYCLE PHYSIOLOGY CARDIOVASCULAR MODULE PHASE II 2007-2008