Posts Tagged ‘paroxysmal’

orthopnea paroxysmal nocturnal dyspnea pnd www.drsvenkatesan.com


Some  Infrequently asked questions in (iFAQ)  in PND 

Is basal rales mandatory during episodes of PND ?

Yes. Most will have. But it should be emphasised orthopnea patients rales are rare since it takes some time for lung congestion take place. If rales appear immediately after lying down it may Indicate severely compromised LV function.

PND vs Orthopnea : Which is reproducuible symptom ?

Obviously orthopnea. PND can never predict which day its going to come as there is CNS component to the circuit in triggering this. (REM sleep, Dreams etc)

How many episodes of PND can occur in one night ?

Usually one. Because PND requires time lag of atleast few hours. Usualy these pateints will not sleep subsequnetly or walking time ensues sooner or later.

Can episodes of PND be prevented ?

Since its volume dependent pulmonary hemodynamic stress , a diuretic at dusk will prevent these episodes in many.

What is the sensitivity of PND for predicting heart disease ?

It has low sensitivity( <30% ) but 75% specificity to diagnose heart disease.

Is PND sign of advanced heart disease ?

No .It has very low sensitivity to predict severity of heart disease.

Can PND and Orthopnea occur at same patient at same time same day  ?

Orhopnea has no time lag.It occurs immediately hence it is obviously  more severe. Many of these patients , however do get into sleep after some time as some sort of compensation or adaptation to neural signals of dyspnea take place.

These patients later on can  get into  the same cycle of PND .However  ,as heart disese (as in cardiomyoapthy ) worsens the pulmonary interstitium shows some reactive fibrotic changes resist water logging in lungs.

PND and orthopnea though share close relationship in terms of pathophysiology , and we cluster it together in symptomatology they are temporally separated in most patients.

PND : is it an equivalent to acute heart failure ?

Yes, it can be called so (If it is due to heart disease*) . It fulfils all criteria of a cardiac failure . LV/LA filling pressure raised , forward output (Cardiac Index may still be normal ) .PND is transient, acute , left sided failure which results in acute oxygen debt for the body which is self corrected usually.

* In volume overloaded , CKD patients PND can occur

What is the relationship between RV dysfunction to PND /Orthopnea?

There is a complex fluid regulatory mechanisms in failing heart.The lung can be congested if and only if the RV function is adequate enough to flood the lungs and at the same time LV function matches it with its inadequacy resulting in persistent congestion. On other words a very high RVEDP  is protective against pulmonary edema (However patient  will feel the dyspneic still due to hypoxia /VP VQ etc !)

Its prudent to give importnce to PND/Orthopnea with reference to balance of RV and LV function. One may recall why pericardial disease where right heart filling is impeded rarely have lung congestion.

Is PND associated with  Angina ?

Yes, it can but generally its not. Angina occurs due to nocturnal sub endocardial Ischemia.This combination occurs in critical  Aortic valve disease.(Both AS/AR)

Is PND a cardiac emergency ?

Difficult question. Most times No, Since its self-limiting especially if the patient knows he is going to settle with his past experience. But it can trigger dangerous events in severely compromised heart.As expected, the first episode creates much panic  and invariably elicits emergency alert.

PND has sinister significance it is due to nocturnal ACS and its a sign of ischemic LVF and requires immediate care.

Which is the most benign form of PND and Orthopnea ?

Students of Medicine should know , medicine is a funny science a symptom so benign in some denotes impending death in some others.

Obese men and women, pregnant can experience terrifying dyspnea at night when they turn around or stretch .This is due to upward movement of diaphragm encroaching lung space.

If you record Mitral inflow doppler filling pattern during an episode of PND what will you find ?

Its quiet simple logic.You do it and find as a learning exercise.(Please don’t make the patient suffer by doing echo at times of distress.One of your colleagues to attend to him as you simultaneously do an echo for academic purpose)

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