congestive heart failure

Question 0

what are the principles behind congestive heart failure?

Answer 0

1. failure of pump - cardiac muscles contract weakly and chambers cant empty properly - systolic dysfunction. chambers cant relax sufficiently - diastolic dysfunction
2. obstruction to low - lesion that prevent valve opening - overworked myocardium work against obstruction
3. regurgitant flow - valve lesion backflow
4. shunted flow - divert blood inappropriately
5. disorder of cardiac conduction - uncoord or blocked
6. rupture of heart or major vessels - discontinuation

Question 1

what are the symptoms of congestive heart failure

Answer 1

dyspnea - 2 types 
lethargy and weakness 
peripheral edema 
jugular vein distension 
pleural effusion and ascities

Question 2

when does congestive heart failure occur?

Answer 2

CHF occurs when the heart cannot generate sufficient output ot meet metabolic demands of tissues

Question 3

what are the causes of congestive heart failure?

Answer 3

IHD 40%
dilated cardiomyopathy 
primary valvular heart disease 
HTN 
regurgitation

Question 4

what are some mechanisms of compensation for reduced myocardial contractility/increased hemodynamic burden?

Answer 4

1. neurohumoral mech
   - RAAS system - when CO drops this is activated to increase circulatory BV hence vascular tone
   - catecholamine stimulation
2. structural change
   - pressure overload states - concentric hypertrophy compensated heart failure
   ventricular dilation comes at expense of inc wall tension and amplifies 02 requirement hence failing heart unable to propel suff 02 to meet demand – decompensated heart failure

-vol overload - eccentric hypertrophy