Peripheral edema in CCF | PGI MCQs for MD MS Preparations

Peripheral edema in CCF is due to: 

A. Increased sympathetic tone 
B. ANP (atrial natriuretic peptide) 
C. Increased hydrostatic pressure 
D. Pulmonary hypertension
E. All of the above

Ans. A. Increased sympathetic tone; (C) Increased hydrostatic pressure :

* Oedema in CCF is due to :

— Activation of Renin angiotensin system. 

---- Increased sympathetic tone via intrinsic renal mechanism. 

— Increased capillary hydrostatic pressure. 

— Chronic hypoxia may cause injury to capillary wall causing increased capillary permeability. 

* Atrial Natri-uretic peptides released from atria in response to volume expansion This peptides cause increasedGFR and inhibit sodium reabsorption.

— Circulating units of ANP and BNP are elevated in CCF but obviously not sufficient to prevent edema formation and they evoke compensatory response tending to reduce cardiac load (preload and after load) by vasodilatation and by enhancing sodium and water excretion. 

---- In oedematous state there is abnormal resistance to actions of Natriuretic peptides