The RNV scan should be performed by a qualified nuclear medicine technologist to obtain and process images under the supervision of a cardiologist, radiologist, or nuclear medicine physician.  

The rest RNV scan does not require any specific preparation.

The exercise RNV scan would require 4 to 6 hours of fasting. Additionally, the patient should avoid caffeinated drinks 12 hours before the procedure and should wear comfortable clothes/shoes. 

The patient is positioned comfortably on the exam table, EKG (electrocardiogram) leads are attached to the chest wall, and a blood pressure cuff is wrapped around the arm. Baseline heart rate, EKG, and blood pressure are recorded before starting the test and then monitored closely during the entire exam.

The scan requires the tagging of the patient's red blood cell (RBC) with the radiotracer (99m-technetium), which could be done in vivo or in vitro and then injecting it (around 20 mCi as per patient's weight) through an intravenous line. After that, the study can proceed using one of three different methods, including first-pass study, gated equilibrium ventriculography, or gated SPECT image acquisition. The EKG gating is done by dividing the cardiac cycle into 16 or 32 frames and using R wave as a trigger to obtain proper sampling. One prerequisite for the EKG gating is less than 10% of premature ventricular contraction at baseline. A variation in the heart rate or rhythm, such as sinus arrhythmia, results in distortion of the data. The exercise scan can be done with a stationary bicycle or a pharmacological agent (dobutamine). 

In the first pass study, the gamma camera acquires the imaging of the heart, lung, and great vessels in a rapid sequence during the initial rapid transit of the radioactive bolus with a 30-degree RAO projection. 

In a gated equilibrium radionuclide ventriculography, images are taken after the radiotracer achieves a state of equilibrium. It acquires images in three different views, including an anterior view, a left oblique view (at 45 degrees) to visualize the septum, and a left lateral oblique view.  While during exercise, only the left anterior oblique view is obtained at different stages of exercise. 

In a gated SPECT acquisition, the structure of interest can be isolated precisely to assess the ventricular segment contractility accurately. It creates long axis, short axis, and three-dimensional volumetric images. The ejection fraction assessed with the SPECT images is more accurate than the planar method due to atrial interference in the planar method, which would underestimate the ejection fraction. 

Qualitative and Quantitative Assessment 

To analyze the data qualitatively and quantitatively, different images, including functional, stroke volume, paradox, and amplitude images, are obtained. In the qualitative assessment, the cinematic display on the screen allows the visual evaluation of the ventricular contractility and wall motion abnormality. While in the quantitative analysis, the computer counts the change in radioactivity in the region of interest (ROI) during a cardiac cycle, which is proportional to the change in the blood volume in that area.  From this, the time-activity curve can be generated to obtain the end-systolic and end-diastolic volume.  The accuracy of calculation depends on the precise selection of the region of interest. Additionally, the regional ejection fraction and contractility undergo an assessment by dividing the ventricle into segments.

The RNV scan is a safe procedure without serious adverse reaction as the scan uses a small dose of the radiotracer, and it gets cleared through the kidney within 24 hours. The radiation exposure from RNV is equivalent to that of a computerized tomography scan (CT scan).

The dobutamine used during the exercise scan could give little nausea, headache, palpitation, or chest discomfort, which usually wears off in a few minutes.

The RNV scan is a gold-standard test to assess the left ventricle function before and during the cardiotoxic chemotherapy treatment. Additionally, it has shown itself to be a cost-effective test for ventricular function monitoring during cardiotoxic chemotherapy.[6] The previous study has reported its usefulness in assessing perioperative cardiac risk and mortality.[7] 

The regional wall motion abnormality reported on scan could signal towards coronary ischemia or infarction. Additionally, it can provide prognostic information for coronary artery disease and an acute coronary event.[8][9] Furthermore, it can aid in the differential diagnosis of dilated, hypertrophic, or restrictive cardiomyopathies. The ventricular synchrony assessed by the radionuclide ventriculography can be helpful prior to CRT as the echocardiographic parameters have not shown the consistency in predicting the cardiac outcome.[3][10]

The primary care provider can use the RNV scan to assess the left ventricular function for any new sign or symptom of CHF, particularly for the patient taking cardiotoxic chemotherapy. The test can be performed in 1 to 2 hours, with results obtained immediately. The patient care should be in coordination with cardiology and oncologist for any drop in ventricular function to adjust the chemotherapy regimen. 

The team coordinator should call the patient to confirm the date, time, and location of the procedure. The nursing staff can call the patient a few days prior to the appointment to brief about test day preparation and expectations. 

On a test day, the technician should monitor the time and protocol. Additionally, the technician should instruct the patient appropriately to lessen the motion and obtain accurate images. 

The patient should receive diligent monitoring closely during the test with the EKG machine. The nursing staff should observe the patient for any allergic reaction to the radioactive tracer and should notify the supervising physician immediately for any allergic reaction.

The patient should be monitored with serial blood pressure reading and continuous ECG rhythm during exercise scan. The facility should be equipped with an emergency response system for a pharmacological exercise scan.