Left Heart Catheterisations (LHC)
Indications/purpose
- Assess arteries after patient presents with chest pain, positive echo stress test
- May perform treatment on the spot or leave complicated cases (e.g., multiple stenosis) to be discussed at the conference (every Mon and Thurs)
Key Actions
- 5 views of LCA and 3 views of RCA are always performed in order to assess the heart in its entirety prior to any intervention
- Label images immediately post stent insertion and when GTN is administered (or take notes on the run number)
- Listen out for GTN or nitrate and the stent size used!
- For post dilation of stent, STENTBOOST/CLEAR (which has a high radiation dose) will be used to clearly visualise stent walls – collimate tightly to the stent
Additional Imaging/Tests
PCI (Percutaneous Coronary Intervention)
- Bare-metal Stent: Short duration of dual antiplatelet (DAP) therapy, higher compliance, less thrombosis risk.
- Drug-eluting Stent: Releases agents over 9-12 months; effective in smaller vessels.
- If more than 1 stent deployed label final image as per this format: Post Stent (Vessel): 2 x 23mm BRAND
LV/Aortogram
- Change acquisition to 15 f/s.
- Catheter advanced into left ventricle to assess function and pressure.
- LV: Calculate ejection fraction; assess for mitral regurgitation.
- A: Check for aortic aneurysm, regurgitation, and dissection.
IMR (Index of Microcirculatory Resistance)
- Used when all the major arteries are deemed proficient, so the cause of symptoms may be smaller vessels
- Helps identify spasms or decreased flow/function in smaller vessels.
- Adenosine is administered to induce hyperaemia.
- Normal IMR result is < 25.
FFR (Fractional Flow Reserve)
- Measures severity of stenosis; calculates blood flow impact.
- Adenosine always administered prior to FFR to mimick heart in a stressed state and induce hyperaemia.
- If FFR ≤ 0.8, intervention may be necessary. FFR of 1 means the pressure before and after the stenosis is equal, thus normal.
- Will usually administer GTN prior, no need to label as standard.
OCT (Optical Coherence Tomography)
- Performed pre-stenting to identify area of stenosis and dimensions
- Useful for differentiating thrombus from plaque.
- Also performed post-stenting and dilation to check apposition of the stent
- Contrast injection with pressure setting < 300 PSI is used
- While the contrast is injected to fill the vessel, the cather is pulled back, obtaining the image (the contrast replaces the blood to get an accurate representation of the interior of the vessel).
IVUS (Intravascular Ultrasound)
- Provides an internal view of the inner lumen, plaque and vessel wall.
- Helps in deciding stent size and length, especially in cases of diffuse disease affecting lumen clarity.
ACH Challenge
- Acetylcholine challenge.
- Stimulates the endothelial muscarinic receptors, leading to either vasodilation (in a healthy endothelium) or vasoconstriction/spasm (in dysfunctional endothelium).
- Like GTN, label post ACH.
ACH Challenge
- Acetylcholine challenge.
- Stimulates the endothelial muscarinic receptors, leading to either vasodilation (in a healthy endothelium) or vasoconstriction/spasm (in dysfunctional endothelium).
- Like GTN, label post ACH.
QCA (Quantitative Coronary Analysis)
- Performed in syngovia
- Measures the degree of stenosis.
- Process: Click the angio tab, calibrate vessel based on catheter size, select area of interest, create report (shows diameter of stenosis), and save.
QFR (Quantitative Flow Ratio)
- Performed in syngovia
- FFR without need of pressure wires
Cardiac Rhythm Management (CRM)
Indications/Purpose
- Diagnose arrhythmia
- Record any abnormal electrical signals
Key Actions
- Change screen display as per procedure step (use cheatsheet)
- Stay awake (long procedures)
- Prepare for femoral access (large devices = need large access)
CRM Examinations
Ablation
- The pt is under GA (takes a while to set up)
- Set up:
- 2 blueys on table (catch blood/prep solution from femoral access)
- Have US machine and TOE (if crossing transeptally), enter pt details onto the TOE.
- After pt is asleep, move the tube to ~75 deg (MORE than 45 for minimal rad dose to anaesthetist) BEFORE draping.
- Used to treat abnormal heart rhythms by ablating small areas of heart tissue.
- Requires precision in locating arrhythmogenic areas - may be mapped using EPS first
- Will typically use TOE to scross the septum - save this image!
- Main action is setting up and then changing the screens as required (e.g. when they are crossing the septum, change to transeptal screen with Sony 1 connected to the TOE machine.)
Pacemakers
- The pt is usually lightly sedated.
- Single (lead in only right ventricle) or dual (also in right atrium)
- Atrial lead used to treat atrial arrhythmias or SA node impairement
- Ventricular lead used to treat complete heart block or significant bradycardia
- Biventricular (leads in both ventricles and right atrium) coordinates the ventricles contractions
- Accessed via subclavian vein into the right atrium and/or ventricle).
- Save final run with the leads and generator
Loop Monitors
- For continuous monitoring of the heart rhythm for pts with fainting episodes/sporadic arrhythmias/palpatations.
- Built in electrodes to sense electrical impulses, signal amplification and data storage/transmission.
- Battery lasts 3 years
Structural
Indications/Purpose
- Abnormalities with the heart structure (walls/septum and valves)
Key Actions
- Setting up the room for femoral access (e.g. TOE or US machines)
- Saving relevant images (e.g. with contrast or device deployment)
- Measuring balloon sizes (for ASDs)
Structural Examinations
TAVI (transcatheter aortic valve implantation)
Indications
Aortic stenosis in patients unsuitable for open-heart surgery
Procedure Steps
- 3 sites of access: Both femoral veins need to be accessed as well as the femoral artery on the opposite side to device delivery (need maximum space for the device and prevent perforation)
- Catheter insertion: 2 pigtail catheters are positioned at the aortic root and LV (save image of crossing into LV!). A higher pressure gradient between the 2 indicates higher level of stenosis. A pigtail catheter which has holes throughout ensures more uniform distribution of contrast, decreasing chances of perforation since a high rate of contrast injection is used during deployment.
-
Temporary right ventricular cardiac pacing: A pacing lead is inserted venously into the RV.
- The pacing lead serves as a backup, as AV block may be transitional post-procedure.
- Rapid cardiac pacing is performed to reduce cardiac output to ensure balloon does not migrate out from annulus (transition point between left ventricle and aortic root)
-
TAVI prosthesis deployment: The prosthesis is loaded in a special delivery catheter prepared by the rep. During deployment, its position can be adjusted/recaptured depending on brand. It may be self-inflating or need post-dilation depending on the model. The tech will enter the lab to pace the heart to 180 bpm to induce tacchychardia and stop cardiac output/motion for easier deployment.
- Gradients
- Aortogram
- Pigtail cather at aortic root
- DSA run: Dr will ask to change aqcuisition mode to DSA when ready. Used to check fem vein for dissections and bleeds near the access point after deployment. A normal contrast run may be used on the opposite side.
Common Complications
- Aortic Dissection (it's a large device!)
- Stroke (especially when a lot of calcification is present during pre-dilation and pushed out)
ASD Closure (Atrial Septal Defect)
A hole between the heart's atrium.
- Blood flows from Left Atrium to Right Atrium , increasing volume of blood in the RA, leading to increased work on the right side.
- Results in mixing of oxygenated and deoxygenated blood.
- Measure the balloon waist size so the appropriate sized device can be used. In the angio tab, calibrate first then using tools make meausrement.
Procedure Steps
- Set up the room as for femoral vein approach (blueys on table, TOE and US machines, arm boards, II turned ~75deg)
-
Vascular Access:
- Right femoral vein is accessed with a needle under US guidance.
- A sheath is inserted into the vein over a guidewire.
- Catheters are put in the sheath and advanced up to the heart.
- Initial Haemodynamic measurements are taken by tech (incl RA, RV, PA, confirm left-right shunting of blood and assess pulmonary hypertension).
- A catheter is advanced through the ASD from the RA to LA using fluoro and TOE. A guidewire is advanced through this and positioned in a stable location like the pulmonary vein.
-
Balloon sizing:
- A measuring balloon catheter is inflated over the ASD to find the accurate size of the defect and confirm correct size of the selected closure device.
- Measure the waist of the balloon (check guide book for instructions).
- On Artis screen, go to angio tab, calibrate first, then using tools make measurement.
-
Device Deployment:
- The delivery sheath (a larger catheter) is advanced over the guidewire and positioned across the ASD.
- The closure device is loaded into the sheath.
-
The device is deployed in two stages:
- The LA disc is deployed first by retracting the sheath and pulled against the foramen for positioning and stability.
- The sheath is then further retracted to deploy the RA disc.
- The device position is checked using fluoro and no residual left-to-right shunting with TOE.
PFO Closure (Patent Foramen Ovale)
Unlike ASD, NOT a congenital heart defect, but occurs when the foramen ovale doesn't close AFTER birth.
Otherwise same procedural steps!