Waveforms Flashcards
Why is EJV not used
EjV is valved and is not directly inclined with svc and ra
A wave
Reflects atrial presystolic contraction
After the p wave
Precedes S1
Prominent a wave
Pxs with reduced rv compliance
Cannon a wave
Av dissociation and contraction against closed tricuspid valve
Pxs with wide complex tachycardias - ventricular in origin
A wave absent
Af
X descent
Fall in atrial pressure
atria relaxes
C wave
Interrupts x descent as ventricle systole pushes on closed tv
X descent follows C
Due to atrial diastolic suction created by vent systole
cont of ventricles causes more spacein pericardial sac,more space for atrium
X descent follows C
Due to atrial diastolic suction created by vent systole
cont of ventricles causes more spacein pericardial sac,more space for atrium
V wave
Atrial filling
Follows s2
Why is v wave smaller than a wave
Normally compliant right atrium
Explain the waveforms in ASD
The a and v waves may be of equal height
v - atrial filling - in asd, filled na agad atrium
Explain waveform in TR
V wave will merge with c wave because of retrograde valve flow and anterograde rightbatrial filling occurs simultaneously
Y descent
Follows v wave peak and reflects the fall in R atrial pressure after tricuspid valve opening
Explain the waveform in pericardial tamponade or tricuspid stenosis
There is resistance in ventricular filling in early diastole BLUNTS the y descent
Explain the waveform in pericardial constriction or isolated severe TR
Y descent will be steep because ventricular diastolic filling occurs early and rapidly
Normal venous pressure should fall by _ after inspiration
3mm Hg..
Failure to decrease in inspiration/ increase in venous pressure upon inspiration - Kussmaul’s sign
Where is Kussmaul’s sign seen?
Right sided volume overload and reduced RV compliance
Constrictive pericarditis Restrictive cardiomyopathies Pulmonary embolism Rv infarction Advanced systolic HF
Explain the pathophysiology of Kussmaul’s sign
Normally, inspiratory increase in right sided venous return is accomodated by increased RV ejection facilitated by an increase in capacitance of the oulmonary vascular bed
In RV diastolic dysfunction and volume overload, RV cannot accomodate with the enhanced volume, the pressure rises.
How to do abdominojugular reflex maneuver
Put a firm and consistent pressure in the right upped quadrant for at least 10 seconds
What is a positive abdominojugular reflex
A rise of more than 3 cm in the venous pressure sustained for at least 15 seconds / shorter time is accepted
Avoid straining or holding breath - falsely elevated results
What can the abdominojugular reflex predict
It can predict heart failure in pxs with dyspnea as well as a pulmonary wedge pressure higher than 15 mmHg
