Set 7 Flashcards
Is echo the best noninvasive diagnostic technique for evaluating pericardial thickening?
Echo is neither sensitive nor specific in the diagnosis of pericardial thickening. This lack of reliability is due to the brightness and reflectivity of the pericardium.
Moreover, the pericardium lies at a depth of 15-20 cm, which is outside the optimal focal zone of most ultrasound systems. Computer axial tomography (CAT scan) or cardiac magnetic resonance imaging (CMR) is more accurate than echo in determining the pericardial thickness.
You just completed an echo study on a patient who has all the echo and Doppler findings for tamponade. What is your next step?
When you have a patient that you suspect is in tamponade you should find echo physician to do an immediate interpretation and get those results to the patients physician.
What are the 3 most likely causes of fibrin or adhesions within the pericardial space?
- Longstanding pericardial effusions
- Metastatic disease with pericardial involvement
- Hemorrhagic effusions that result in clot formation within the pericardial space
What is the most common etiology of constrictive pericarditis?
The most common cause of constrictive pericarditis is recurrent pericarditis.
Repeated cycles of inflammation and healing cause the pericardium to become rigid, fibrotic, and sometimes calcified.
Other causes are chest radiation therapy and TB
What physical findings might be presented by a patient with constrictive pericarditis?
- Dyspnea
- Ascites
- Pericardial knock
- Jugular venous distention
What is the cause of a pericardial knock?
A pericardial knock occurs in early diastole and is caused by the abrupt cessation of ventricular filling
What is the definitive method for diagnosing constrictive pericarditis?
Cardiac catheterization is the definitive method for diagnosing constrictive pericarditis.
It is better than echo in this setting because catheterization documents equalization of the right and left ventricular diastolic pressures
Describe the M-mode and 2D echo findings associated with constrictive pericarditis
In constrictive pericarditis, M-mode findings include: flattened posterior wall motion during diastole, abnormal septal motion (early diastolic bounce), and 2 parallel lines within the pericardium.
2D findings include: abnormal septal motion (early diastolic bounce), immobility of the pericardium, and a dilated IVC
Describe the Doppler findings associated with constrictive pericarditis
In constrictive pericarditis, Doppler findings include: mitral and tricuspid regurgitation, a decreased early mitral inflow velocity (>25%) during inspiration, and mitral inflow pattern similar to restrictive cardiomyopathy (large E-wave and short A-wave)
Define systemic hypertension
Systemic hypertension is persistent elevation of the systolic blood pressure to greater than 140 mmHg and/or elevation of the diastolic blood pressure greater than 90 mmHg. These high blood pressure readings might be obtained on 3 separate occasions at least 1 week apart
What are the physical signs of systemic hypertension?
Patients with uncomplicated hypertension are almost always asymptomatic.
Headache, tinnitus, and dizziness may be seen in hypertensive patients but also occur in patients without hypertension
What are the vascular complications of systemic hypertension?
- Cerebrovascular accident (stroke)
- Kidney disease
- Coronary heart disease
- Congestive heart failure
- Peripheral vascular disease
- Aortic dissection
What sometimes happens to the left ventricle late in the course of systemic hypertension?
Left ventricle failure sometimes occurs and the left ventricle becomes dilated and hypocontractile just like any other dilated cardiomyopathy
What are the echo findings associated with systemic hypertension?
- Left ventricular hypertrophy
- Left atrial enlargement (usually mild)
- Possible aortic dilatation or dissection
What are the Doppler findings associated with systemic hypertension?
- Abnormal mitral inflow pattern featuring an A-wave greater than the E-wave and prolonged deceleration that indicates decreased left ventricular relaxation
- Aortic regurgitation (in the presence of aortic dilatation)
Define pulmonary hypertension
Pulmonary hypertension denotes a peak pulmonary artery pressure greater than 40 mmHg.
It has many causes including idiopathic, chronic mitral stenosis or regurgitation, pulmonary embolism, and Eisenmenger’s syndrome
What are the physical signs of pulmonary hypertension?
Physical signs of pulmonary hypertension include dyspnea during exertion (in early stages of the disease), dyspnea at rest (in advanced stages), syncope, weakness, and precordial chest pain
What are the echo findings associated with pulmonary hypertension?
- An enlarged right atrium and ventricle
- Right ventricular hypertrophy
- Thickening of the interventricular septum
- Flattening of the interventricular septum in the short axis view (in both systole and diastole)
- An absent “a” wave and/or mid systolic closure of the pulmonic valve (flying W) in M-mode
What causes absence of the “a” wave?
The “a” wave occurs when atrial contraction causes the right ventricular pressure to increase, thereby deforming the closed pulmonary valve.
In patients with pulmonary hypertension, the pulmonary artery pressure is so high than even during atrial contraction, the pulmonic leaflets do not move. Therefore, no “a” wave is produced
When the left ventricular short axis view demonstrates flattening of the interventricular septum, how can you determine if the problem is volume or pressure related?
Flattening of the interventricular septum will be seen in both volume and pressure overloaded right ventricles.
In fact, there is never a purely volume or pressure overloaded situation - there is always some combination of the 2.
One way to determine which is dominant (volume or pressure) is to watch the septal motion throughout the cardiac cycle.
Most of the time the septum will return to normal in systole (round up) when volume overload is predominant.
The septum will stay flattened during systole when the problem is due to pressure.
How is the pulmonary artery pressure calculated on the basis of the tricuspid regurgitant jet?
Right ventricular systolic pressure (RVSP) can be calculated by adding the tricuspid regurgitation gradient (converted to mmHg by 4V2) and the estimated right atrial pressure
How is the pulmonary artery pressure assessed using the Doppler pulmonary artery acceleration time?
The pulmonary artery pressure can be calculated from the pulmonary artery Doppler spectral trace by measuring the systolic acceleration time.
The normal systolic acceleration time is greater than 120 msec, as measured from the onset of flow to peak velocity.
In patients with pulmonary hypertension, the acceleration time is decreased.
In general, an acceleration time of less than 75 msec indicates at least moderate pulmonary hypertension (in adults)
Describe the 3 main classifications of cardiomyopathy
- Hypertrophic (with and without obstruction)
- Dilated (congestive)
- Restrictive (infiltrative)
What is the typical echo appearance of hypertrophic cardiomyopathy?
The ventricular walls are thickened (symmetrically or asymmetrically) and the ventricular chambers are reduced in size
What is the typical echo appearance of dilated cardiomyopathy?
The ventricles are enlarged, and contractility is decreased. One or both chambers may be affected
What is the typical echo appearance of restrictive cardiomyopathy?
The ventricles are hypertrophied, the cardiac chambers are nearly normal in size, and the myocardium appears bright.
What is the most common cause of hypertrophic cardiomyopathy?
Genetic.
Just over half of all patients with hypertrophic cardiomyopathy have an autosomal dominant gene trait.
In other patients, the disease appears to occur spontaneously
What causes systolic anterior motion (SAM) of the mitral valve?
Systolic anterior motion (SAM) of the mitral valve occurs when the left ventricular outflow tract is narrowed by septal hypertrophy.
During systole, the velocity in the narrowed LV outflow tract increases, pulling the mitral chordae and leaflets toward the septum creating a mid-late dynamic outflow tract.
What are the physical findings with obstructive cardiomyopathy?
- Dyspnea on exertion: this is the most common symptom, occurring in 90% of symptomatic patients
- Angina (which occurs in 75% of symptomatic patients)
- Syncope
- Sudden death
List the common abbreviations associated with hypertrophic cardiomyopathies and state what each abbreviation means
- ASH = asymmetric septal hypertrophy
- HCM = hypertrophic cardiomyopathy
- HOCM = hypertrophic obstructive cardiomyopathy
- IHSS = idiopathic hypertrophic subaortic stenosis
How does the administration of amyl nitrite affect the murmur associated with hypertrophic obstructive cardiomyopathy (HOCM)?
The murmur associated with hypertrophic obstructive cardiomyopathy is usually harsh, systolic, and of a crescendo-decrescendo type.
It is best heard between the cardiac apex and the left sternal border. In response to amyl nitrite, this murmur will increase.
What happens to a murmur associated with hypertrophic obstructive cardiomyopathy when the Valsalva maneuver is performed?
Like amyl nitrite, the Valsalva maneuver causes an increase in the systolic murmur associated with hypertrophic obstructive cardiomyopathy
Describe the echo (M-mode and 2D) appearance of hypertrophic obstructive cardiomyopathy (HOCM)
- Left ventricular hypertrophy (symmetric or asymmetric)
- Small left ventricular cavity
- Systolic anterior motion (SAM) of the mitral valve if there is obstructive to outflow (LVOT)
How is pulsed Doppler examination useful in assessing hypertrophic cardiomyopathy?
Pulsed Doppler performed from the apical window localizes the size of the obstruction.
When the sample volume is slowly moved from the cardiac apex toward the aortic valve and an obstruction is encountered, the flow velocity increases and changes from laminar to turbulent on the Doppler spectral trace.
How is continuous wave Doppler useful in the assessment of hypertrophic cardiomyopathy?
Continuous wave Doppler records the peak gradient both at rest and after provocation with the Valsalva maneuver or amyl nitrite. The spectral trace often shows the late peaking systolic jet typical of a dynamic obstructive cardiomyopathy
What physical findings might be presented by a patient with constrictive pericarditis?
- Dyspnea
- Ascites
- Pericardial knock
- Jugular venous distention
What is the cause of a pericardial knock?
A pericardial knock occurs in early diastole and is caused by the abrupt cessation of ventricular filling
