Path- Hem DyN I Flashcards
What creates the first heart sound (S1)?
The mitral valve closing (beginning of sytole)
What creates (S2) the second heart sound?
The aortic valve slamming shut
What is the Valve between the R Atrium and the R ventricle?
Trucuspid Valve
What is the valve between the R ventricle and Pulmonary Artery (lungs)
Pulmonary valve
What is the approximate pressure in the pulmonary Artery?
25 mmHg about the same as R ventricle
What is preload?
The ventricular wall tension at the end of diastole just before contraction (sytole)
How is preload measured?
By end diastolic pressure, normally determined by end diastolic blood volume
What is the Frank-Starling mechanism?
The physiologic relationship between end-diastolic volume and force of contraction
What is Afterload?
The resistance the ventricle must overcome to pump out its contents.
What are some common causes of decreasesed ventricular compliance?
- Fibrosis
2. Amyloidosis
What is restrictive cardio myopathy?
When ventricular compliance decreses below the ability of the atrium to fill it normally.
What is dyastolic dysfunction?
Impaired cardiac filling
What is sytolic dysfunction?
Impaired cardiac pumping
What are the usually causes of systolic dysfunction?
Impaired contractility or greatly increased afterload.
What does sytolic function normally affect?
- Decreases amount of blood ejected from the ventricle
- Decreases the stroke volume
- decreases the ejection fraction
Does diastolic dysfunction typically affect EJECTION FRACTION?
NO
What are the five major categories of the factors determining the hearts function as a pump?
- Preload
- Afterload
- contractility
- Compliance
- Heart Rhythm
What is heart failure?
The inability of the heart to pump sufficient blood to meet the needs of the body.
What is the most common cause of Chronic heart failure?
Old myocardial infarctions (ischemic cardiomyopathy)
How does uncontrolled severe hypertension cause heart failure?
By causing severe afterload exceeding the ability of the heart to compensate.
What does aortic stenosis cause?
Increases afterload (increased pressure required to force open stenotic valve) resulting in heart failure
Which pathologies generally lower the ejection fraction?
- Aortic Stenosis
- Severe Hypertension
- Coronary artery disease
Which pathologies generally preserve ejection fraction?
- Left ventricular hypertrophy
- Restrictive cardiomyopathy
- Pericardial disease
What is the most common symptom of heart failure?
Dyspnea