Dyspnoea on lying flat
It is a sign of advanced heart failure
Lying flat increases venous return and in patients with left ventricular impairment may precipitate pulmonary edema.
Lying flat causes a steep increase in left atrial and pulmonary capillary pressure resulting in pulmonary congestion and severe dyspnea.
This severity can be graded by number of pillows used at night.eg -three pillow orthopnea
Causes 1.Biventricular failure
PND-Paroxysmal nocturnal dyspnea
Sudden breathlessness waking the patient from sleep.caused by accumulation of alveolar fluid.patient may choke or gasp for air , patient open windows in an attempt to relieve their stress
Causes 1.Left heart failure
2.cardiomyopathy
3.Aortic valve disease
Reference -Macleod edition 13 page 102
