Page 295 - Hall et al (2015) Principles of Critical Care-McGraw-Hill

CHAPTER 28: Interpretation of Hemodynamic Waveforms 199

A. B.

Pra Pra
60
30 v v v
v v v
a
x
y
0
0

C.

Pra

v
30 – c

Y
INSP INSP
0 –
FIGURE 28-26. Right atrial pressure (Pra) tracings in patients with tricuspid regurgitation. A and B. prominent v waves. C. broad c-v wave with large y descent. Scale in millimeters of mercury.

consistent with pulmonary embolism. One hemodynamic difference differentiate atrial flutter from sinus tachycardia and paroxysmal supra-
between these two conditions is that massive pulmonary embolism ventricular tachycardia, even with the aid of a 12-lead ECG. Although
33
is characterized by a significant increase in the Ppad-Ppw gradient, the response to adenosine is often the best way to define the underly-
whereas the latter should be unaffected by RV infarction. 50 ing atrial rhythm, in some cases atrial flutter may also be diagnosed by
29
Arrhythmia evaluation is sometimes aided by analysis of the Pra detection of “flutter” waves in the Pra tracing (Fig. 28-28). Similarly,
waveform. Narrow-complex, regular tachyarrhythmias at a rate of 140 to the presence of regular cannon a waves during the tachyarrhythmia
180 beats per minute are common in the ICU. It is sometimes difficult to suggests atrioventricular dissociation due to a reentrant supraventricular

ECG
ECG

Part
100 Part
150

Pra
30 30 Pra
y y y
x x x
x y x y x y

FIGURE 28-27. Right atrial pressure (Pra) tracing in patient with cardiac tamponade showing blunted y descent with preservation of x descent. After pericardiocentesis, the y descent
becomes more prominent. See text for discussion of physiology. Part, arterial pressure.

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