The Sonographer Attachment Programme At USA Report : Mayo Clinic Rochester = Limited TTE=

5.8 Mayo Clinic Stress Echo Lab Gonda 6:

Protocol For Limited Tranthoracic Echocardiogram

      Principles

      This protocol is designed to provide guidance when Echo Lab staff are performing a limited or goal-directed transthoracic echocardiogram.

    Indications : If patients have had an echocardiogram within the last six months, it may be more appropriate to perform a goal-directed exam to answer a specific clinical question.The sonographer or ACS will typically consult with the referring or reviewing physician to ensure that adequate information is obtained. Commonly used limited exams are outlined below.

      Medications

·         Contrast agents (Definity)

·         Agitated Saline

·         Amyl Nitrite

Patient Education

     

    Information about echocardiography is printed on each patient’s itinerary of Clinic tests.  Prior to beginning the study, the imaging sonographer or physician explains the procedure and process of reviewing results; any additional teaching (i.e., Valsalva maneuver, etc.) is provided as needed. Explanation of the test result is deferred to the referring physician.

Standard Protocols

Stroke Volume & Cardiac Output

·       Obtain data

Þ    LVOT diameter        

Þ    Measurement of LVOT velocity and TVI

Þ    Heart rate

·      Calculate cardiac output per established standards

Regurgitation

·         Evaluate cardiac chamber size and function

·         Use Color Flow to assess regurgitation

·         Quantitate regurgitation using PISA and continuity equation

Mitral stenosis

·         Obtain left ventricular stroke volume

·         Obtain mitral valve mean gradient and TVI

·         Obtain mitral valve pressure halftime

·       Calculate mitral valve area by pressure halftime and continuity equation methods

Aortic stenosis

·         Measure LV cavity dimension and wall thickness

·         Measure LVOT diameter

·         Obtain LVOT velocity and TVI

·         Obtain AV peak velocity and TVI (check multiple windows)

·         Calculate aortic valve area

Hypertrophic Cardiomyopathy

Evaluate cardiac chamber size, wall thickness and function, Obtain resting LVOT or mid-cavity gradient, Obtain LVOT or mid-cavity gradient during Valsalva maneuver, Obtain resting LVOT or mid-cavity gradient with administration of amyl nitrite if indicated (see Echo Lab amyl nitrite procedural guideline)

Diastolic Function

Interrogation of mitral inflow: Deceleration time,  A wave durations, E and A wave velocities, E/A ratio, DTI: e’ velocity, E/e’ ratio, LA volume index, Pulmonary veins: systolic, diastolic and atrial reversal velocities, atrial reversal durations

Left  Ventricular Function: Follow-up chemotherapy, follow-up intervention for CAD

Evaluate cardiac chamber sizes, Calculate ejection fraction by 2-D or M-mode LV dimensions, or by biplane Simpson’s technique, Calculate stroke volume and cardiac output, Obtain data for assessment of diastolic function, Limited color flow imaging, Check for pericardial effusion from subcostal view

Strain

·         Acquire standard images for amyloid, HCM or dyssynchrony referral

·         Analyze strain data

Pericardial Effusion: Follow-up after pericardiocentesis, re-check pericardial effusion

·         Evaluate cardiac chamber size and function

·         Evaluate for presence of pericardial effusion from multiple windows

If significant effusion is present, evaluate for two-dimensional and Doppler indications of cardiac tamponade

·        Chamber collapse

·        Respiratory variation of PW Doppler flow of mitral valve, pulmonary veins, tricuspid valve, and  hepatic vein and superior vena cava flow

Pulmonary hypertension

·         Evaluate cardiac chamber size and function

·         Limited Color Flow

·         Obtain left ventricular stroke volume and cardiac output

·         Obtain TR velocity for estimation of pulmonary artery pressure

·         Obtain data for and calculate RIMP