Reasons to implement this program: 

A.     The Mayo and Cleveland Clinics have demonstrated great success with nurse supervised dobutamine stress echo at high volumes and at all levels of risk.  Published reports have shown minimal complications at an equal rate with physician supervised vs. nurse/sonographer supervised stress echos.  

B.     To increase the efficiency of the laboratory, nurse/sonographer supervised stress echos can eliminate wasted time waiting for physicians to become physically available to supervise stress tests.  The nurses and sonographers will be able to more efficiently use their time with overall benefit to the echo laboratory’s efficiency.  

C.     Our laboratory’s complication rate is very low for serious cardiac arrhythmias and chest pain deemed truly anginal.  Any complications have generally been patients with true cardiac disease who could be identified as “at risk” prior to the stress test. 

D.     The outpatient exercise laboratory performs the majority of stress tests without direct physician supervision including patients with severe cardiomyopathy. 

E.      We now have 2 full time nurses.  Both have extensive clinical experience and are fully capable of recognizing and treating ST changes and arrhythmias that occur during stress echo tests. 

F.      F.  Our sonographers have the experience to recognize wall motion abnormalities that occur during stress echo tests. 

G.      The cardiology staff is oftentimes not promptly available to supervise stress echos because of busy patient care clinical responsibilities. 

In summary, nurse/sonographer supervised dobutamine stress echo should be safe for the patient, improve the efficiency of the echo laboratory, and allow for optimal use of physician time.

IDENTIFYING LOW RISK PATIENTS FOR DOBUTAMINE STRESS  

Inclusion Criteria: 

1.      Patients who are status post heart transplantation who are presenting for routine follow-up and who have had a prior dobutamine stress echo without events (significant arrhythmias) or stress induced wall motion abnormalities. 

2.      Patients presenting for preoperative evaluation who have none of the exclusion criteria.   

Exclusion Criteria:

 NURSE TO EVALUATE: 

1.      Patients with a prior history of myocardial infarction or who are presenting for evaluation of new onset of shortness of breath or chest pain. 

2.      Patients with thoracic or abdominal aortic aneurysm, stroke, peripheral vascular disease or diabetes.

3.      Resting systolic blood pressure < 100 mmHg or > 175 mmHg. 

4.      Patients with ECG evidence of  prior Q-wave myocardial infarction, abnormal ST segments or T wave inversions, left bundle branch block (QRS > 120 msec) or prolonged QT interval (> 500 msec), or pacemaker.

5.      Patients with a history of syncope or sudden death.  Patients with a history of ventricular tachycardia/fibrillation or who have an AICD or pacemaker in place. 

6.      Potassium < 3.5 or > 5.5 if the value is available on an inpatient. 

7.      Hgb < 8.5.

SONOGRAPHER TO EVALUATE: 

1.       Patients with technically difficult images. 

2.      Patients with resting wall motion abnormalities or severe valvular abnormalities.  Heart transplant patients with resting wall motion abnormalities noted on prior studies are not excluded if the resting wall motion abnormalities are the unchanged. 

3.  Patients with a resting left ventricular outflow tract velocity > 2 m/sec.

LOW RISK DOBUTAMINE STRESS ECHO ELIGIBILITY CHECK LIST FOR POST HEART TRANSPLANT OR PREOPERATIVE EVALUATION PATIENTS

PATIENT NAME:____________________________ DATE____/______/______

NURSE SCREENING:______________________________________________

1.  History or ECG evidence of prior Q-wave myocardial infarction?                   YES            NO

2.  Horizontal or downsloping ST segment depressions or ST elevation?               YES            NO

3.  Recent history of chest pain or shortness of breath?                                     YES            NO 

4.  History of syncope, sudden death, VTACH / VFIB, or AICD, pacemaker?          YES            NO

5.  ECG with left bundle branch block (QRS > 120 msec) or QT > 500 msec?         YES            NO

6.  Systolic blood pressure < 100 mmHg and  > 175 mmHg?                                  YES            NO

7.  Normal sinus rhythm on digoxin?                                                                 YES            NO

8.      Diabetes mellitus (except for heart transplant patients for routine study)?      YES            NO

9.    Hgb < 8.5                                                                                                YES            NO

10.  History of peripheral vascular disease, stroke or aortic aneurysm?                 YES            NO

11.  Potassium < 3.5 or > 5.5 if available on an inpatient?                                    YES            NO     

SONOGRAPHER SCREENING:______________________________________

1.  Technically poor echo images for wall motion assessment?                              YES            NO

2.  Resting wall motion abnormalities (WMA) or new WMA in heart TX pt?             YES            NO

3. Severe valvular abnormalities or LVOT velocity > 2m/sec?                               YES            NO

If the answer to all the above questions is NO or if there are questions about the patient’s eligibility, then contact the attending echocardiographer before proceeding.   If the attending physician is not readily available, inform the cardiology fellow in the echo lab that you will be performing a study and request (s)he remain available in the echo lab until you inform them the test is completed.

ECHO ATTENDING AVAILABLE:__________________________________                    YES            NO

CARDIOLOGY FELLOW AVAILABLE:_____________________________

1.      The nurse will evaluate the patient for candidacy using the inclusion/ exclusion criteria.

2.      The sonographer will evaluate the quality of images and the presence of wall motion abnormalities or severe valvular disease.

3.      If the nurse and sonographer agree the patient is a candidate, the nurse will call the attending physician before proceeding and to make sure a physician is available (i.e. cardiology fellow must be in the echo department or attending physician must be in close proximity until the MD receives a call the test is completed).

4.      Dobutamine/Atropine/Handgrip Protocol:

A.      Dobutamine up to 50 mcg/kg/min will be used to achieve > 85% of the age predicted heart rate.  A minimum of 30 mcg/kg/min will be used if the HR% has not exceeded 105%.

 B.  Handgrip exercise will be started at the end of the 30 mcg/kg min stage of dobutamine if the patients % heart rate is < 70 % of predicted.

C.  Atropine 0.25 mg will be given at the end of the 30 mcg/kg/min stage of dobutamine if the heart rate is < 50% of predicted and the sonographer sees no wall motion abnormalities.

 D.   Atropine 0.25 mg will be given at the end of the 40 mcg/kg/min stage of dobutamine if the heart rate is < 70% of predicted and the sonographer sees no wall motion abnormalities.

 E.  Atropine 0.25 mg will be given at the end of the 50 mcg/kg/min stage of dobutamine if the heart rate is < 80% of predicted and the sonographer sees no wall motion abnormalities.

 F.      A final atropine 0.25 mg dose will be given at the end of the 50 mcg/kg/min stage and 2 minutes after the 3rd dose of atropine if the heart rate is < 80% of predicted and the sonographer sees no wall motion abnormalities.

 5.  CALL THE AVAILABLE MD UPON COMPLETION OF THE TEST.

 ENDPOINTS FOR TERMINATION OF DOBUTAMINE INFUSION AND APPROPRIATE INTERVENTIONS/TREATMENT

1.       Achievement of > 85% target heart rate with at least 30 mcg/kg/min stage of  dobutamine.  Do not exceed > 105% of the target heart rate with any dose of dobutamine.

2.      50 mcg/kg/min of dobutamine and atropine 1 mg given.

3.      New wall motion abnormality.  Stop the dobutamine.  Call the attending for early interpretation.

4.      Chest pain felt to be typical of angina (anterior chest tightness, squeezing or heaviness).  Stop the dobutamine and call the available MD.  If the chest pain is not relieved within 3 minutes of termination of dobutamine, administer NTG 1/150 sublingually.  Chest pain felt to be atypical for angina (sharp or atypical in location) continue with the dobutamine as long as there are no  EKG abnormalities (see #5) or a new wall motion abnormality.

5.       EKG changes:  > 1mm ST segment elevation or > 2 mm horizontal or downsloping ST depressions 8 msec (2 small boxes) from the J point (terminal portion of the QRS) in 2 leads.  Stop the dobutamine and call the available MD.

6.       Ventricular triplets, nonsustained or sustained VTACH or VFIB.  Stop the dobutamine.  The sonographer should call the available MD and obtain the crash cart.                         

A.  For nonsustained VTACH wait for 1 minute after terminating the dobutamine and administer a 1 mg/kg bolus of lidocaine only if there is a recurrence of VTACH > 10 beats or continued frequent VTACH > 3 beats. 

B.     For VFIB, bolus with lidocaine 1 mg/kg min.  Call a condition A by calling x3131.

Begin CPR as appropriate.

7.      Sustained atrial tachycardia or atrial fibrillation.  Call the available MD.   If the arrhythmia persists 1 minute after termination of dobutamine administer 1 mg of inderal IV and repeat every 5 minutes to decrease heart rate < 100/minute.  Hold inderal if systolic BP is < 90 mmHg.

8.      Intolerable symptoms (severe nausea/vomiting; severe headache).  Stop the dobutamine.

9.      Hypotension defined as systolic BP < 90 mmHg.  Stop the dobutmaine.  Treat with 250 NS bolus and repeat up to 1 liter.

10.  Hypertension defined as systolic BP > 220 mmHg or diastolic BP >110 mmHg.  Stop the dobutamine.

CALL THE AVAILABLE MD UPON COMPLETION OF THE TEST.