According to the Starling's principles regarding fluid exchanges through the capillary wall, the fluid
membrane and a balance between opposing filtrative and absorbing forces:
Where k = filtration coefficient defining the fluid conductance across the capillary membrane, CHP
= intra-capillary hydrostatic pressure, IHP = interstitial hydrostatic pressure, πif = colloid osmotic
pressure of interstitial fluid and πc = plasma colloid osmotic pressure.
Pulmonary capillary hypertension is the straightforward hemodynamic condition of cardiac
pulmonary edema, along with the failure of lung fluid clearance capacities to rapidly compensate the
excess of fluid transudation across the capillary membrane . Total pulmonary extravascular water
volume is closely related to the extent and the duration of increase in pulmonary capillary pressure.
However, low plasma colloid osmotic pressure due to hypoproteinemia is likely to modulate the
pulmonary capillary pressure threshold of pulmonary edema formation.
Reduced exercise capacity has been found to be associated with basal or stress-induced
pulmonary capillary hypertension in chronic congestive HF, irrespective of LV systolic function.
Elevated LV diastolic pressures directly contribute to reduced exercise capacity in the setting of
chronic HF, along with reduced cardiac output, lung dysfunction and peripheral factors such as
skeletal muscle abnormalities, deregulation of peripheral neural activity and early lactate formation.
-The peak early diastolic mitral E velocity is primarily influenced by:
Left atrial pressure > LV relaxation > LV systolic pressure
-The spectral tissue Doppler-derived peak early diastolic E' velocity at mitral annulus is
regarded as a noninvasive surrogate for LV relaxation, although its preload dependence has been
reported in the setting of normal myocardial function.
-E/E' ratio is assumed to overcome the influence of ventricular relaxation on peak E velocity and
reflect left atrial pressure
|E/E' has been found to be more accurate than natriuretic peptides for non-invasively determining
LV diastolic pressures.
-E/E' allows only a semi-quantitative assessment and values of
>10 for lateral
>12 for septal
>11 for average E/E'
predict pulmonary capillary pressure >15 mmHg in the presence of preserved LV systolic function
-E/E' is unreliable in these conditions:
.Organic mitral valve disease
.Basal LV wall motion abnormalities related to LBBB
-A recent prospective study has confirmed the lack of specificity of the symptom of exertional dyspnea
for the diagnosis of congestive HF (inconclusive PPV of 48%) in a large, unselected patient group.
Non-invasively determined pulmonary capillary pressure at rest and during exercise is likely to be helpful for
establishing the cardiac contribution to exercise intolerance, particularly among patients with confounding
co-morbid conditions such as anemia, obesity and respiratory disease, which are frequently observed in this
-E/A: 0-10 10-15 >15 =elevated left atrial pressure (avg lateral and septal)
-TEI > 0.5 is abnormal (measure of diastolic dysfunction)
|Tissue Doppler of lateral/septal wall >60 = Dyssynchrony