Society of Nuclear Medicine (India) Guidelines for Procedure and Reporting of Equilibrium Gated Radionuclide Angiocardiography: Revisiting Treasure Trove Lost in Plain Sight

Common indications and current clinical utility:

1. Evaluation of systolic and diastolic dysfunction.

2. Evaluation of regional wall motion abnormalities.

3. Evaluation of ventricular volumes at stress and rest.

4. Heart failure with preserved ejection fraction.

5. Evaluation of chemotherapy-induced cardiotoxicity.

6. Evaluation of coronary artery disease.

7. Evaluation of cardiac dyssynchrony in advanced cardiac failure.

Radiopharmaceuticals

^99mTc labelled human serum albumin (HSA) was used prior to the 1970s. Since a large quantity of albumin is sequestered in pulmonary capillaries, the target-to-background ratio was low. The resultant image was of relatively poor quality.

HSA labelling was virtually replaced by red blood cell (RBC) labelling after 1970. RBC labelling provides a favourable target-to-background ratio. It helps imaging blood pool at equilibrium. Hence, the counts in the defined region of interest (ROI) will be directly proportional to the volume of blood.^[1-6]

Patient preparation

1. Patient’s identity should be thoroughly checked.

2. Attenuating material over the chest, like metallic objects, pendants, breast prosthesis, should be removed during acquisition.

3. It is advised to review the recent chest X-ray whenever available. The dimension of cardiac silhouette, orientation of pacemaker with cardiac silhouette, and pleural/pericardial effusions should be made out.

4. Resting ERNA does not require fasting.

5. If pharmacological stress with dobutamine is planned, the patient should be advised to remain fasting for 4 to 6 hours. Beta blockers should be stopped for 48 hours prior to the study.

6. Patient height and weight should be recorded.

7. It is advisable to have two separate venous accesses for stannous and pertechnetate injection if the in vivo labelling method is chosen. It is important to inquire if the previously placed venous access was heparinised. Care should be taken not to inject stannous pyrophosphate/pertechnetate in such venous access inadvertently. Alternatively, hep-lock venous lines should be liberally flushed before injection of radiotracer / stannous pyrophosphate.

8. Drug history should be obtained to make sure that the patient is not on any medicines that would either interfere with RBC labelling or alter heart rate response during physical/pharmacological stress.

Labelling techniques of RBC

1. In vivo labelling

2. In vitro labelling with commercially available kits

3. Modified in vitro labelling

The Physician needs to assess various factors that affect the labelling of RBCs [Fig 1]. It is important to note the history of autoimmune diseases and recent contrast-enhanced cross-sectional imaging. Efforts should be made to avoid interference by drugs that affect labelling.

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Fig 1:

Factors affecting RBC labelling

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The objective of RBC labelling is to obtain a high target-to-background ratio and to acquire scintigraphic data at equilibrium

It is preferable to administer 200mg to 400mg of potassium perchlorate orally, to reduce undesired visualisation of the thyroid and stomach.

Note

1. Reliable Barcoding should be practised to maintain complete verification of patient identity.

2. The in vitro labelling procedure should be performed in a laminar flow hood.

3. Biosafety methods should be followed while handling human blood.

4. Care should be taken to maintain strict aseptic conditions while radiolabelling and injecting the blood sample.

The objective of ERNA is to obtain images of high spatial resolution

Precautions while performing gated acquisition

• The electrodes used for cardiac gating should be secured on the skin in order to ensure an optimal ECG signal.

• The cardiac rhythm should be observed to rule out marked heart rate variability that could interfere with the procedure and interpretation of ERNA results.

• The simultaneity of the R wave triggered by the gating device and the QRS complex should be verified before initiation of the study.

Imaging is performed in the supine position

a) Camera

Small Field of View (SFOV) Gamma Cameras are ideally suited for this purpose. While imaging with Large Field of View (LFOV) Gamma Cameras, the zoom factor should be adjusted so that the heart occupies approximately 50% of the Useful Field of View (UFOV).

b) Collimator

• For most resting ERNA procedures, a standard parallel hole, low-energy, all-purpose (LEAP) collimator is sufficient. Low-energy, high-resolution collimators (LEHR) provide high-resolution images at the cost of additional imaging time. It is recommended to acquire resting ERNA studies with the LEHR collimator.

• During exercise ERNA, it is important to acquire as many counts in a two-minute interval, and hence the LEAP collimator is an acceptable trade-off.

• A 30-degree slant-hole collimator, if available, could be chosen.

c) Energy window: 140keV ± 10%

Acquisition parameters for ERNA at rest

Prepare the patient’s chest for ECG electrode placement. Connect a 3-lead or 5-lead ECG with an appropriate gating device. Comfort the patient by explaining the simplicity of the test, and observe the ECG and heart rate. If required, reposition electrodes/ECG leads to obtain a sharp signal.

Frame mode/list mode

Count density:

• It is advisable to acquire 250 kilo counts/frame in the best septal view and 125 kilo counts/frame in anterior and lateral views.

• A total of at least 6 million counts (250 kcounts X 32 frames = 8 million) should be acquired in the best septal view to get the best images for assessment of diastolic parameters. Anterior and lateral views should be acquired for 3 million counts (125kcounts X 24 frames = 3 million).

Matrix: 64*64

Pixel depth: Word mode

Zoom factor: 2 to 2.5, to be adjusted to an extent that the cardiac chamber occupy 50% of the imaging field of view.

The left anterior oblique (LAO) acquisition should be obtained at an angle that allows the best separation of the right and left ventricles (best septal or best separation view). Technologists should try to review the images on the persistence scope by rotating ±10 degrees before committing to the angle of best separation. A craniocaudal angulation of 10° to 15°, for the separation of atria from ventricle, should be given whenever possible. However, some of the recent designs of dual-head gamma cameras might not provide the option of craniocaudal tilt.

Anterior view is ideally obtained by rotating the camera 45 degrees medially (- 45 degrees) from the best septal view (true anterior view), and the lateral view is obtained by rotating the camera 45 degrees laterally (+ 45 degrees) from the best septal view (true lateral view).

The best septal view is used for quantification.^[1,8,9]

The technologist involved in data acquisition should have a basic understanding of the anatomy of cardiac chambers.

Blood pool gated SPECT study

The main advantage of the SPECT approach is that the separation of the RV and LV allows for the measurement of both RV and LV parameters. The absence of overlap of different cardiac chambers eliminates the need for background subtraction. Due to the larger dimension of the LV blood pool compared to the myocardial thickness, the effect of the partial volume effect reduces and potentially improves accuracy in volume measurements (especially EDV).

An acquisition similar to myocardial perfusion imaging should be performed.

SPECT acquisition parameters

1. Camera: Large field of view

2. Collimator: LEAP or LEHR,

3. Energy window: 140keV ± 10%

4. Acquisition Range of 180 Degrees (45 degrees RAO to 135 degrees LPO), 32 or 64 projections, 25sec per frame, 8 to 16 frames/cycle, and 64*64 matrix, VPC threshold 20% to 50%.

5. Imaging:

• Position the patient supine on the imaging table with hands raised above the head. Explain the entire imaging procedure and the need to remain in a relaxed state of mind to have a regular cardiac rhythm. Comfort the patient with adequate blankets. If the patient has difficulty in tolerating the imaging room temperature, provide an arm and knee rest. Request the patient to maintain regular breathing, to avoid coughing, and to avoid any activity that may introduce image distortion.

• Prepare the patient’s chest for ECG electrode placement. Connect a 3-lead or 5-lead ECG with an appropriate gating device. Comfort the patient by explaining the simplicity of the test, and observe the ECG and heart rate. If required, reposition electrodes/leads to obtain a sharp signal.

• Position the heart in the centre of the imaging field of view. Rotate the detector through the entire imaging range to ensure that the heart remains in the field of view in all the frames. Adjust the detectors at the closest possible distance that clears the patient’s shoulders and body.^[1,8,9]

• Initiate SPECT acquisition from 45-degree RAO to 135-degree LPO (180 degrees)

Stress ERNA

1. Position the patient supine on the bicycle ergometer with feet down. Connect the ECG leads and verify the signals. Record the supine blood pressure—record blood pressure in all the stages and during recovery.

2. Position the detector anteriorly over the chest. Make sure that the heart is located centrally in the FOV. Make sure that hand grips are positioned appropriately, and the feet are away from the detector.

3. Set up the acquisition protocol in a 64*64 matrix, word mode, and 24/32 frames per cycle. Terminate at 300kilo counts per frame. R-R variability acceptance ±25%window.

4. Acquire lateral view images by placing the patient`s left arm above the shoulder. Move the detector as close to the patient`s body as possible.

5. Determine the best septal view / left anterior oblique (LAO) view and acquire the images.

6. Set up the computer for seven acquisitions. 64*64matrix, word mode, 16frames per cycle. The acquisition should terminate in two minutes. Alternatively, if possible, perform list mode continuous acquisition. Do not apply the R-R threshold window.

7. For physical stress, secure the patient's feet to the pedals of the ergometer. The detector should remain in the best septal view / LAO view.

8. The 7-stage standard exercise protocol is applied (300, 600, 900, 1200, 1500, and 1800kg.m/min). 300kg.m/min is approximately 50watts.

9. The patient should be instructed to exercise at a predetermined number of revolutions/pedaling per minute. The stage continues for three minutes. After 55seconds, 2-minute data acquisition should start automatically.

10. The exercise is continued by increasing the workload by 300kg.m/min. While ECG and hemodynamic parameters are monitored during the stages. Continue the stress stages until the patient can no longer maintain the exercise level.

11. After the exercise, with the feet on the pedals, wait for 55seconds and initiate a 2-minute acquisition.

12. Dobutamine stress involves 4 phases. Each phase lasts for 3 minutes. Infusion is started with 10µg per kg body weight, continued with an increment of 10 µg per kg body weight per phase, up to a maximum dose of 40 µg per kg body weight. Hemodynamic and ECG parameters are monitored in each phase and during recovery. Imaging remains essentially the same.

13. If quantification is planned, withdraw a 10 mL blood sample from the patient after completion of the stress protocol. Count it for two minutes under the gamma camera.^[10]

Standard data processing

Step1: Review the cinematic display of the best septal, anterior, and lateral views. Ensure images are of good quality. Observe various blood pools in the image and their orientation with the left ventricular blood pool.

Step2: Creating end diastolic and end systolic regions of interest.

The objective is to get as accurate a time activity curve of the left ventricle as possible [Fig 2 and 3].

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Fig 2:

Normal ERNA (Equilibrium Gated Radionuclide Angiocardiograph) study

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Fig 3:

Normal LV (Left Ventricle) time activity curve.

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Note: The accuracy of the time activity curve depends on:

1. Technical adequacy of raw data

2. Diligent regions of interest

3. Information density per frame

4. Sharpness of separation of chambers

EF Analysis involves drawing the LV ROI in the best septal view. The three methods for creating LV ROI are:

1. Automatic method

2. Semiautomatic method

3. Manual method

In the automatic method, a combination of second derivative edge-detection and count threshold algorithm is used for the determination of the LV boundary. It is important to review these ROI before proceeding to EF analysis. If automatic/ semiautomatic ROI are inconsistent with the LV boundary, they should be adjusted manually. Phase amplitude images should provide enough details to identify mitral and aortic valvular planes. A single pixel should be allowed between the ROI and the septal, apical, and lateral walls. ROI should be tight in the valvular planes.

Background ROI: A 2 to 3-pixel-wide crescent-shaped ROI should be drawn 1 to 3 pixels away from the LV ROI. Pixel-based background (Bkg) subtraction will be performed. Hence, it is important to make sure that the background ROI does not fall on non-cardiac blood pools like the descending thoracic aorta, pulmonary vessels, spleen, stomach, and liver.

Review the phase and amplitude images before creating the diastolic LV ROI.

After mathematical subtraction of the numerator, we get

LV diastolic parameters

Indices of diastolic filling can be derived from the LV time activity curve when the acquisition is performed between 32 and 64 frames per R-R interval. A 4th-or 5^th-order Fourier filter / polynomial filter should be applied to the scintigraphic data. Some of the commonly used filling parameters are 1. Peak filling rate (PFR) and 2. Time taken from end–systole to reach peak ventricular filling (tPFR).

• PFR: It is computed by obtaining the first derivative of the LV time activity curve. The first major positive peak on the first derivative curve corresponds to the point on the LV time activity curve, where the count rate is fastest.

  1. PFR is measured in counts per second.

  2. It is further normalised to end diastolic counts.

  3. PFR is finally represented as end diastolic volume (EDV) per second.

• tPFR is expressed in milliseconds.

• The first derivative curve of the LV time activity curve also shows a second positive peak. It corresponds to the peak left atrial contribution to left ventricular filling. It is sometimes referred to as atrial filling rate (AFR). One should carefully observe the cinematic display of the true lateral view to visualise the atrial contribution. In abnormal cases, it appears as a rapid jet of volume emptied into the LV preceding LV diastole. Increased atrial contribution to LV filling represents a severe form of diastolic dysfunction [Fig 4].

  

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  Fig 4:

  Diastolic parameters and first derivative curve in a normal subject.

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• PFR and AFR correspond to ‘E’ and ‘A’ waveforms of mitral velocity on the Doppler Echocardiography.^[11-13]

• Normal values:

  1. PFR should exceed 2.5 EDV/second.

  2. tPFR should not exceed 180 milliseconds.

  3. AFR is usually 1.0 EDV/second.

  4. PFR / AFR ratio should be > 2.5.

Methods of LV volume measurement

1. Geometric method

2. Count proportional method

Geometric method: It involves the mathematical assumptions applied to procedures like invasive coronary angiography (CAG). Since the spatial resolution of images obtained from ERNA does not match that of CAG, volume analysis by this method might not be accurate.

Count proportional method: At equilibrium, counts derived from any cardiac chamber should be directly proportional to the corresponding chamber volume. Such a relationship could be established by two methods:

1) Counting a reference blood sample: A small amount of labelled blood should be withdrawn and counted under the gamma camera. Background subtraction should be performed.

EDV derived by this method might not be accurate since LV blood pool counts are not attenuation corrected. The accuracy of the LV region of interest also directly influences volume assessment. Chest wall markers can be used to determine the depth of the centre of the LV cavity. Depth correction can be performed using an assumed attenuation coefficient. Alternatively, a linear regression equation can be used to compute absolute LV EDV from attenuated LV end-diastolic counts. These methods are subject to standard errors, for which correction methods should be derived in laboratories.^[14]

2) Reference volume within the image: This method does not involve blood sampling. The descending thoracic aorta, being a cylindrical structure, can be used as a reference blood pool. The relationship between counts and the volume of blood in a cylinder could be established.

The ratio of total counts within the cavity (TC) and the maximum pixel count (MPC) together with the area of this pixel (Apix) according to Massardo et al.^[15]:

LV ESV is calculated from EDV and EF

3) Alternate method: Measurement of LV blood volume requires the following information from the best septal view and the 10 ml sample:

1. Left ventricular end-diastole counts (CT) (EDC)

2. Left ventricular end-systole counts (ESC)

3. Total number of cardiac cycles acquired in the study (TC)

4. Duration of each frame in the composite cardiac cycle (sec) (DUR)

5. Two-minute counts in the 10ml blood sample (CT) (BLD)

Analysis requires that the end-diastole and end-systole counts be normalised (n) to counts per second, as follows:

The blood sample must be normalised to counts per second per millilitre as follows:

Note: If there is a significant delay (greater than 20 minutes) between the patient study and counting of the blood sample, then a decay correction factor should be applied to the blood counts. Use the following nomograms to calculate the end – diastole and end-systole volumes.

Parametric images

Phase image: First harmonic phase analysis of raw images in the best septal view generates a two-dimensional Fourier phase image and a cosine curve characterized by its amplitude and phase angle^[16,17]. The phase angle refers to the timing or the placement of the cosine curve within the cardiac cycle, from 0° to 360°. The earliest ventricular phase angle relates to the time of onset of the ventricular contraction; the mean ventricular phase angle reflects the mean time of the onset of the ventricular contraction, and the standard deviation of the ventricular phase angle relates to the synchrony of the ventricular contraction. The atria and ventricles are normally 180° out of phase. Phase angles are computed for each pixel, and coloured phase images with corresponding histograms are generated. Phase angle can be converted to milliseconds by the formula: (phase angle/360 °) × RR interval (milliseconds). Mean phase angle and standard deviation (SD) can be computed for the right and left ventricles separately. It is advisable that each institute generate its own normal phase parameters and evaluate dyssynchrony accordingly [Fig 5 and 6].

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Fig 5:

A case of LBBB (Left Bundle Branch Block) and severe LV dysfunction. Note the delayed phase of contraction of LV compared to RV, represented by color coding in the phase image and phase histogram. Septum is out of phase, indicating paradoxical septal wall motion (red color).

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Fig 6:

A case of severe LV dysfunction and distal LAD (Left Anterior Descending Artery) infarct. Amplitude image shows reduced contractility in the apex and apicoinferior segments. The phase image and histogram show delayed contractility (hypokinesia, golden yellow colour).

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Amplitude image derives its name from its relationship with the heigh of the fitted cosine curve. It represents the maximum change in counts between the peak and the nadir of the cosine curve. Pixels with the greatest change in counts will be assigned the brightest colour. The rest of the pixels are scaled accordingly. Colour coding allows differentiation of a group of pixels with a smaller amplitude and hence regional ventricular systolic dysfunction [Fig 7].

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Fig 7:

Amplitude image.

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Stroke volume image: When an end-systolic image is subtracted from an end-diastolic image and the difference is colour-coded, a stroke volume image will be generated. The end systolic counts of atria, aorta, and dyskinetic images exceed end diastolic counts. Hence, the subtraction yields negative values. Such negatively valued pixels are set to zero in stroke volume and are dropped out [Fig 8].

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Fig 8:

Ejection fraction (EF) and stroke volume (SV) image.

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Paradox image: When an end diastolic image is subtracted from an end systolic image and colour coded, a paradox image is generated. Normally, atria and aorta are highlighted in this image. Ventricles appear photopenic. However, the paradoxical septum and any dyskinetic segment get highlighted with colour-coded pixels in the ventricular region Fig 9.

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Fig 9:

A case of apical aneurysm. Note the out-of-phase apex in the phase image. The stroke volume image shows photopenia in the region of the apex. Paradox image shows reddish pink coloured apex indicating dyskinesia.

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NOTE: It is worth having a second visual review of the cinematic display of raw data once the parametric images are derived.

Data analysis and interpretation

Review the cinematic display of all three views simultaneously. Spatial and temporal relationship of chambers, other blood pools should be assessed. Wall motion of the left ventricle should be qualitatively assessed.

1. In the anterior view, the LV apex, inferior wall/inferoseptal wall, and anterolateral walls are visualised. RV, right atrium, RV outflow tract, and pulmonary artery are visualised. Despite overlap between RV and LV inferior wall in this view, the higher count density in LV allows clear visualisation of the inferior wall.

2. In the best septal view, LV, RV, and the interventricular septum are seen. It allows the observer to make an impression about the chamber size and orientation. Apex / apicoinferior segment and lateral wall are visualised. Septal motion should be carefully assessed. The more horizontal the heart, the better the inferior wall visualisation; the more vertical the heart, the better the visualisation of the apex.

3. In the lateral view, the inferior wall of the LV, the apex, and the left atrium are visualised. This is the best view to evaluate the wall motion of the inferior wall, atrial pattern of contractility, and its contribution to LV filling.

Chamber size, great vessels, and pericardial space should be assessed qualitatively. Pericardial effusion appears as a photopenic halo around the cardiac blood pool. Left atrial/ventricular thrombi could be seen as space-occupying photopenic areas associated with akinetic/dyskinetic/aneurysmal segments. Non-visualisation of the left atrium would indicate a left atrial thrombus.

The Physician should also observe any atrial/ventricular conduction abnormalities while reviewing three cinematic blood pool images.

Regional lV function

Synergy and synchrony are the terms used to describe regional LV function. Synergy refers to the force of contraction. Synchrony refers to the timing of contraction. Loss of synergy is defined in terms of the extent of loss of contractility.

What is normal wall motion?

Synergetic and synchronous contraction of all walls of the LV is considered normal. It is identified qualitatively by reviewing the cinematic display of three views. The speed of cinematic display should be consistent during qualitative assessment. It is also worth looking at the regional LVEF image to know the relative contribution of respective walls.

Hypokinesia: It means the extent of contraction is reduced, leading to reduced contribution to LVEF. Regional hypokinesia is interpreted by comparison with other walls. The extent of reduction can be relatively defined as mild, moderate, or severe. It is difficult to define these terms when there is a global reduction of contractility. It is important to refer to LVEF, amplitude, and phase images under such circumstances. Hypokinetic segments have different colour coding on the phase image [Fig 7]. Tardokinesia, a term that refers to the abnormal slowness of contraction of a segment/wall of the LV.

Akinesia: It means the absence of any detectable wall motion. Usually, fibrotic nonviable segments are akinetic. Stunned myocardium /hibernating myocardium might also appear akinetic at rest.

Dyskinetic: It means a segment/wall of myocardium bulges out while the rest of the walls are contracting and moving inwards during systole. A thinned-out, fibrotic, nonviable aneurysmal segment typically demonstrated dyskinesia. Rarely, stunned/hibernating myocardium might also appear dyskinetic. These segments appear ‘out of phase’ on the phase images and also appear on the paradox image [Fig 9].

Paradoxical movement: It is usually referred to as the interventricular septum in conditions like left bundle branch block (LBBB) and certain conditions leading to RV overload. The septum appears move towards the LV in early systole and moves towards the RV for the rest of systole. It, however, demonstrates contractility. The phase image will show the septum as out of phase. It will also get highlighted in the paradox image. A dyskinetic segment will also be out of phase and never show contractility. With experience, the observer will be able to differentiate paradoxical wall motion and dyskinesia [Fig 5 and 9].

Radiation exposure from ERNA study

Refer to Table 1 for data on the effective dose estimate per injected dose. All efforts should be made to keep the patient dose and exposure to radiation workers as low as reasonably achievable. Weight-based patient dosing should be followed. It is advisable to follow the appropriate use guidelines to choose patients for ERNA. The latest software that uses iterative reconstruction algorithm, resolution recovery, and noise reduction should be used for SPECT reconstruction, so that activity for the procedure/acquisition time could be significantly reduced.^[18-20]

Reporting ERNA

• Patient demographics, age, gender, and identification number should be mentioned.

• The date of the procedure should be mentioned.

• Study protocol, including RBC labelling method, camera, collimation, imaging views, and methods, should be mentioned.

• Gating method, beat acceptance/rejection information, and cardiac rhythm during acquisition are optional.

• The image quality of the study could be mentioned.

• Indication of the study should be mentioned.

Findings

1. Cardiac chamber dimensions, ventricular thickness, and pericardial space description should be given.

2. Systolic Function [Table 2]

   Table 2: Normal reference range of quantitative parameters

   Resting LVEF	Range	Significance
   Normal	50% to 75%	Indicates normal LV pumping efficiency.
   Mildly Reduced	41% to 49%	Indicates mild or early myocardial injury.
   Moderately Reduced	30% to 40%	Indicates heart failure
   Severely Reduced	< 30%	Indicates severe heart failure and its potential complications.
   Abnormally High	> 75%	Indicates LV hypertrophy or hypertrophic cardiomyopathy.
   LV EDV	Male: 60–120 mL
   	Female: 58–103 mL
   LV ESV	50 to 60 mL
   LV Phase standard deviation	< 45 msec	> 45msec should be considered LV intraventricular dyssynchrony
   	< 40msec	> 40msec should be considered interventricular dyssynchrony
   Resting RVEF	> 40%	RVEF is usually lower than LVEF, indicating its higher compliance and end diastolic volume

   LV: Left ventricle, LVEF: Left ventricular ejection fraction, RVEF: Right ventricular ejection fraction, EDV: End diastolic volume, ESV: End systolic volume

   1. Global LVEF and description of regional LV wall motion are essential.

   2. Global RVEF and systolic emptying indices of LV are optional.^{[17, 21-25]}

3. Parametric images:

   Visual assessment of Phase and Amplitude images

   1. Regional reduction of contractility observed on amplitude images should be mentioned.

   2. Hypokinesia, Akinesia, and dyskinesia observed on phase images should be mentioned.

4. Quantitative parameters of dyssynchrony should be mentioned in the indicated cases.

5. Volume Estimates: EDV, ESV, and Stroke Volume are essential.

6. Diastolic parameters: PFR, tPFR, and atrial contribution should be mentioned.

7. If stress ERNA is performed, the following should be mentioned:

   1. LVEF at baseline, peak stress, and recovery.

   2. Qualitative assessment of regional wall motion in all stages,

   3. Quantitative data of global left and right ventricular function and volumes in all stages.

   4. Stress ECG and hemodynamic changes.

   5. Non-cardiac vascular anomalies.

8. Study information should be concluded by giving a final impression on:

   1. Systolic function, the degree of dysfunction (mild moderate/severe), extent (regions involved), and severity of hypokinesia (mild/moderate/severe), and reason for the comment.

   2. In cases of severe LV dysfunction and dilated cardiomyopathies, the presence of dyssynchrony (LV / RV / interventricular) should be mentioned.

   3. Diastolic function, degree of dysfunction (mild/moderate/severe), and reason for the comment.

   4. Comparative assessment with the prior study should be performed. Changes in systolic/diastolic function should be mentioned.^{[3, 21-25]}