How common is edema legs in diastolic heart failure ?
- Can not occur.
- As common as systolic failure
- Can occur in significant number.
Answer : 4
Response 3 may be correct as well .
When cardiac failure was originally defined by Framingham criteria many decades ago , the entity of diastolic heart failure was non existent .The classical triad of edema legs, raised JVP, basal rales invariably meant systolic , congestive hart failure. We will , never ever know how many of the Framingham cohort had isolated diastolic heart failure .
For edema to occur there need to be water and sodium retention .For sodium and water to accumulate either of the two things should happen (Hypoprotienemia, Lymphatic dysfunction excluded)
- Increased venous pressure
- Reduced renal clearing of water and salt.
When both join together edema is classical and full blown.
In isolated LV diastolic heart failure the raise in systemic venous pressure is less pronounced .So , edema legs is less conspicuous. but in any type of failure the net cardiac index tend to decline at least marginally . Kidneys are the first organ to sense this , and the nephrons goes for a huddle and begin to retain sodium and water as if body is going to face severe water and salt scarcity .(It is a false alarm actually ! )
Neuro humoral mechanism is “Alive and well” in any heart failure whether it is systolic diastolic , forward ,backward etc. so , edema can indeed occur in isolated diastolic heart failure
Please note , the classical edema that occur in restrictive cardiomyopathy , constrictive pericarditis are due to severe impediment to right sided filling and elevated the lower limb venous pressure .
Other important determinants of edema legs.
- The baseline renal function.
- Intra vascular volume status.
- The associated HT induced vascular changes.
- Serum protein levels.
- Venous tone.(A good venous pump in conditioned legs develop edema late )
- Integrity of lymphatic circulation.
- Subcutaneous fat density and interstitial tissue resistance.
All can modify the local hydro static pressure .These factors operate in various quantum’s and for this reason only selcted few develop significant edema in cardiac failure .
Also read . Why some patients with cardiac failure never develops edema legs ?
* Please note , the terms diastolic dysfunction and failure can not be used interchangeably. Dysfunction is often a echo parameter while failure is its clinical counterpart .Both can be dissociated in time , failure may never follow dysfunction .Most episodes of diastolic dysfunction is transitory in nature.