Hemodynamic Rounds
Dr.N.PraveenMD,DM (Cardiology)
Pressure Waveform Analysis and
Interpretation of Cardiac Pathophysiology
THE TRICUSPID VALVE
Introduction
• Right atrial pressure waveform reflects the function of and flow
across the tricuspid valve.
• The most commonly observed hemodynamic waveform.
• When assessing the small but clinically important gradients across the
tricuspid valve, two simultaneous and matched pressures from two
equisensitive transducers will provide the precise hemodynamics.
• Normal Right Atrial Waveforms
• Cardiac Rhythm and Right Atrial Pressure
• Systolic Regurgitant Waves
• Pulsatile Venous waves
• Right atrial –Right ventricular gradients
• Right Atrial Pressure Artifacts
Normal Right Atrial waveform has
• 1. A wave more than V wave
• 2.V wave more than A wave
• 3.X wave more than Y trough
• 4.X trough more than V wave
1. A wave more than V wave
2.V wave more than A wave
3.X wave more than Y trough
4.X trough more than V wave
Normal Right Atrial waveform
Important
• Simultaneous Right ventricular and right atrial pressure waves
to be measured using fluid filled transducer systems.
• Identical matching of the RA and RV diastolic pressures is the
norm for analysis.
• The “ A” wave (atrial contraction) of the right atrial pressure corresponds to the “A” wave of the right ventricle.
• The “V” wave corresponds to the opening of the tricuspid valveon the downslope of the RV pressure tracing.
• The pressure immediately after the “A” wave, the X descent, falls and does not begin to increase until late in systole.
X descent
Y descent • As RV pressure falls below the
RA pressure, the tricuspid valve
opens, releasing the atrial
pressure ( the Y descent of the
“V” wave).
• C wave – notch immediately after “A” wave or the initial upstroke
of ventricular pressure.
The higher ejection velocity and faster development of the RV
pressure causes more oscillations of the transducer system than that
of the RA pressure, and therefore, a high frequency “ringing” is
observed as a notch on the upstroke before the systolic peak of the
RV and a rapid dip (negative overshoot in early diastole.
• This common artifact using fluid filled systems is important to
recognize when assessing tricuspid and pulmonary gradients.
• 62 yr male, Aortic stenosis, Right atrial and left atrial pressure waveforms. Pullback of a fluid filled Transseptal Brockenbrough catheter.
• The mean left atrial pressure is elevated – approx. 22 mm Hg with striking A and V
waves.
• X trough – movement of the tricuspid or mitral valve away from the atrium when
intrapericardial pressure is decreasing immediately after ventricular contraction
begins and LV volume falls.
• Y trough – occurs with opening of the tricuspid valve.
• There is a reciprocal relationship between pressure and right atrial or venous flow.
• Flow is virtually absent at times of peak positive A and V waves.
• The left atrial V wave is giant (twice the mean pressure) and occurs in AS in absence of MR.
• V wave – pressure volume relationship of the atrium
• A non compliant or stiff ventricle is associated with large A and V waves.
• The Left atrial “ V ” waves are greater than V waves on the right atrial pressure where the A wave dominates.
• The atrial arrhythmias may significantly alter the waveforms (a’)
• Normal Right Atrial Waveforms
• Cardiac Rhythm and Right Atrial Pressure
• Systolic Regurgitant Waves
• Pulsatile Venous waves
• Right atrial –Right ventricular gradients
• Right Atrial Pressure Artifacts
• Right atrial pressure waves may be distorted during cardiac arrhythmias.
• The large, spiked waves represent “C” waves or giant cannon waves.
• This occurs when atrial contraction falls out of sequence with normal ventricular systole and the atria contract against a tricuspid valve closed by the increased right ventricular pressure during ejection.
• Size of the C wave is dependent on the timing of the atrial contraction relative to ventricular filling and the position of the tricuspid valve.
• Cannon waves to be differentiated from systolic tricuspid regurgitant waves.
• Can be iatrogenically induced – Pacemaker
• Can be spontaneously observed due to abnormalities in conduction.
• The pressure tracing demonstrates brief, sharp peaked waves, less prominent than the atrial contraction waves of the previous tracing.
• The dysynchronous ventricular pacemaker timing relative to atrial dissociated contraction appears responsible.The wider “C” type wave of beat 3 with the P wave falling on the QRS.
• The high pressure spike with narrow width also suggests artifact from catheter imapction,but the timing seqeunce is highly consistent with cannon type waves.
• Normal Right Atrial Waveforms
• Cardiac Rhythm and Right Atrial Pressure
• Systolic Regurgitant Waves
• Pulsatile Venous waves
• Right atrial –Right ventricular gradients
• Right Atrial Pressure Artifacts
• Positive systolic pressure waves on the right atrial tracing may
also be due to an incompetent or occasionally a stenotic
tricuspid valve.
• 50 year old woman with atrial fibrillation and history of rheumatic fever has increasing pedal edema and dyspnea. Simultaneous right ventricular and right atrial pressures were measured with two fluid filled catheters.
• The right atrial pressure, matching with right ventricular pressure in diastole.
• The right atrial and ventricular A waves are absent as patient is in atrial fibrillation.
• A prominent Y descent occurs after the point of maximal right atrial pressure (V wave) and falls sharply with the drop of RV pressure.
• Slope of the atrial pressure during RV ejection is generally proportional to the severity of TR.
• The compliance or pressure –volume relationship of the atrium will determine the size and character of the pressure wave.
Gradient rose across the systolic
period of right ventricular ejection, the
most common pressure wave pattern
of tricuspid regurgitation.
• Normal Right Atrial Waveforms
• Cardiac Rhythm and Right Atrial Pressure
• Systolic Regurgitant Waves
• Pulsatile Venous waves
• Right atrial –Right ventricular gradients
• Right Atrial Pressure Artifacts
39 year old woman, Severe ascites and dyspnea at rest has large V waves during jugular vein examination
and a pulsatile liver.
• The simultaneous right ventricular and right atrial pressure show the
marked and more striking upslope of right atrial pressure during right
ventricular ejection with a V or S systolic wave to 32 mm Hg.
• The more rapid rise of right atrial pressure indicates severe TR.
• Early diastolic ventricular pressure drop is associated with an early right
atrial right ventricular pressure gradient which equilibrates before the first
one third of diastole following a rapid decline – high flow and not
necessarily a significant tricuspid stenosis.
• The faster rate may also contribute to the early right atrial –right ventricular diastolic gradient.
• The regurgitant S wave, occuring slightly earlier than a V wave, is very prominent on physical examination and can be seen in the neck and even transmitted down to the femoral vein.
• Femoral vein pressure may be as high as 35 mm Hg.Thus , on puncture of the femoral vein, a venous pressure pulse may be observed.
• The timing of the V wave is coincident with the electrocardiographic T wave, but may be easily confused as an arterial pulse of low amplitude.
• Normal Right Atrial Waveforms
• Cardiac Rhythm and Right Atrial Pressure
• Systolic Regurgitant Waves
• Pulsatile Venous waves
• Right atrial –Right ventricular gradients
• Right Atrial Pressure Artifacts
• The right atrial pressure demonstrated prominent regurgitant wave with fusion of A and V waves with an absent X trough and a marked Y descent.
• The rhythm is atrial fibrillation
• A wave absent on RV tracing.
• The C wave of ventricular contraction can be seen.
• Because of the resonant qualities of some fluid filled systems,thepressure waveform with a blunted A wave and X descent may occasionally be confused with the M configuration of constrictive or restrictive physiology.
• The broad and wide upsloping right atrial pressure of TR is importantly associated with a persistent gradient of approximately 4mm Hg across the tricuspid valve throughout diastole.
• M pattern of constrictive physiology
• The first panel demonstrates elevated and matched right atrial pressures.
• The rhythm was atrial bigeminy.
• Loss of distinct right atrial A and V waves.
• Right atrial and right ventricular diastolic gradient can be seen.
• The gradient persists throughout diastole in both long and short cycles.
• Normal Right Atrial Waveforms
• Cardiac Rhythm and Right Atrial Pressure
• Systolic Regurgitant Waves
• Pulsatile Venous waves
• Right atrial –Right ventricular gradients
• Right Atrial Pressure Artifacts
• 1.The most common artifacts in the measurement of right atrial pressure icnlude failure to match the zero positions or transducer gain sensitivity of the 2 fluid systems.
• Importance : when tricuspid valve disease is suspected,precisecalibration and equisensitivity of transducers are critical because small gradients may have large clinical importance.
• An increase in right atrial mean pressure during inspiration is a
common sign of physiological abnormalities of atrial filling
especially prevalent in patients with constrictive or restrictive
physiology.
• Another common and disturbing artifact of fliud filled pressure
systems,especially in measuring right atrial and right heart
pressures is that of excessive catheter fling of an underdamped
pressure system.
• This artifact is very common with usage of balloon tipped
pulmonary artery flotation catheter.
• The left side of the figure shows right heart pressure recorded prior to pressure system manipulation to reduce the underdampened signal.
• Interpretation of waveforms and other details of these pressure tracings cannot be discerned from the rapid high frequency ringing artifact of the underdampened system.
• To improve hemodynamic recordings while continouslymeasuring pressure,a 50% saline and contrast solution to be instilled through the catheter.
Calibration of Pulmonary catheter
Reference
• Cathetrization and cardiovascular diagnosis 21:278-286(1990)
• Hemodynamic Rounds - Interpretation of cardiac pathophysiology from pressure waveform analysis
Morton J.Kern, Ubeydullah Deligonui