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📚 BSc Cardiac Technology - 3rd Year
Paper I: Cardiac Catheterization Laboratory - Basics
Complete Study Guide | Target: 90%+ Marks
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CHAPTER 1 - TYPES OF CATHETERS & STERILIZATION
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🔑 Definition
A catheter is a long, thin, flexible hollow tube made of polyurethane or nylon, used to enter blood vessels and heart chambers to record pressures, inject contrast, and perform procedures.
1.1 Types of Catheters
A) Diagnostic Catheters (for recording pressures and angiography)
| Catheter Name | Shape | Used For |
|---|
| Judkins Left (JL 3.5 / 4 / 5) | Pre-shaped curve | Left Coronary Artery (LCA) |
| Judkins Right (JR 4) | Single gentle curve | Right Coronary Artery (RCA) |
| Amplatz Left / Right | Flat, round tip | Alternative for coronaries |
| Pigtail | Curled pig-tail tip | Left Ventriculography, Aortography |
| Multi-purpose (MP) | Single curve | Right heart, multiple uses |
| Swan-Ganz | Balloon-tipped | Right heart pressures, PCWP |
B) Interventional Catheters (for procedures)
- Guiding catheters - larger lumen to pass wires and balloons during PTCA
- Balloon catheters - used in PTCA (angioplasty)
- Ablation catheters - used in EP study for radiofrequency ablation
📊 DIAGRAM 1 - Catheter Shapes
JUDKINS LEFT JUDKINS RIGHT PIGTAIL
___ __ ___
/ \ / | / o <-- curled tip
| | | | |
| | | | |
| | \__| |
| |
(Double curve) (Single curve) (Multiple holes)
SWAN-GANZ CATHETER
===========================O <-- Balloon at tip
Port 1 (Proximal - RA)
Port 2 (Distal - PA)
Thermistor port
Balloon inflation port
1.2 Catheter Sizes
- Measured in French (Fr) size
- 1 Fr = 0.33 mm diameter
- Common sizes: 5Fr, 6Fr, 7Fr, 8Fr
1.3 Catheter Cleaning and Packing
Steps:
- Rinse immediately after use with sterile water
- Flush lumen to remove blood/contrast
- Check for cracks, kinks, or damage
- Dry completely
- Coil loosely and pack in sterilization pouch
- Label with date and catheter type
- Sterilize and store
1.4 Sterilization Techniques
📊 DIAGRAM 2 - Sterilization Methods
STERILIZATION METHODS FOR CATHLAB
|
_____|_____
| | |
HEAT CHEMICAL RADIATION
| | |
Steam Glutaraldehyde Gamma rays
(Autoclave) / ETO gas
Detailed Table:
| Method | Temperature | Time | Advantages | Disadvantages |
|---|
| Autoclave (Steam) | 121°C or 134°C | 15-30 min | Fast, non-toxic, reliable | Damages plastic, rubber, heat-sensitive items |
| Ethylene Oxide (ETO) Gas | 55°C | 4-8 hours | Best for heat-sensitive items | Toxic residue; needs aeration 24-48 hrs |
| Glutaraldehyde (2%) | Room temp | 10 hrs for sterilization; 20 min for disinfection | Cold sterilization, cheap | Toxic fumes, skin/eye irritant |
| Gamma Radiation | Room temp | Minutes | No heat or moisture; long shelf life | Expensive; needs special facility |
✏️ Model Exam Answer (5 marks):
Q: Describe the sterilization methods used in the Cath Lab.
Answer: Sterilization is the complete destruction of all microorganisms including spores. In the cardiac catheterization laboratory, the following methods are used:
-
Ethylene Oxide (ETO) Gas - Most preferred for heat-sensitive catheters and electronic equipment. The gas acts by alkylation of DNA of microorganisms. Advantage: effective on all materials. Disadvantage: toxic, requires 24-48 hours aeration before use.
-
Glutaraldehyde (2% solution) - Used for cold sterilization. Items are soaked for 10 hours for complete sterilization. Used for endoscopes and catheters that cannot withstand heat. Disadvantage: toxic fumes.
-
Autoclave (Steam under pressure) - 121°C at 15 psi for 15 minutes. Most reliable and fastest. Used for metal instruments, linen, glassware. Not suitable for catheters.
-
Gamma Radiation - Used industrially for pre-packaged disposable items like catheters and syringes.
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CHAPTER 2 - CATH LAB SETUP & IMAGING EQUIPMENT
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2.1 Preparing the Cath Lab for a Diagnostic Study
Steps of Preparation:
Before the Patient Arrives:
- Clean and disinfect the table and lab
- Switch on and test fluoroscopy / X-ray equipment
- Test pressure monitoring system - zero and calibrate transducers
- Load contrast media in power injector
- Test defibrillator and emergency resuscitation cart
- Prepare sterile trolley with catheters, wires, manifold, syringes
- Check oxygen supply, suction machine
- Enter patient data in computer/cine system
When Patient Arrives:
- Confirm patient identity, allergy history
- Check informed consent
- Connect ECG leads and pulse oximeter
- Set up IV line
- Prepare access site (groin/wrist)
📊 DIAGRAM 3 - Cath Lab Layout
╔══════════════════════════════════════════╗
║ CARDIAC CATH LAB ║
║ ║
║ [Control Room] [Monitor Bank] ║
║ ┌──────────┐ ┌───────────────┐ ║
║ │ Computer │ │ BP | ECG | O2 │ ║
║ │ Recorder │ │ Monitors │ ║
║ └──────────┘ └───────────────┘ ║
║ ║
║ ┌──────────────────────────────┐ ║
║ │ C-ARM FLUOROSCOPY UNIT │ ║
║ │ │ ║
║ │ [X-ray tube] ─── [Patient] ─│─ [Image Intensifier/FPD]
║ │ │ ║
║ └──────────────────────────────┘ ║
║ ║
║ [Power Injector] [Emergency Cart] ║
║ [Defibrillator] [Sterile Trolley] ║
╚══════════════════════════════════════════╝
2.2 Table Movement
The cath lab table can move in multiple directions to position the patient correctly:
- Longitudinal (head-to-foot) movement
- Lateral (side-to-side) movement
- Isocentric rotation - table and C-arm rotate together, keeping the heart in center
2.3 Image Intensifier Movement (C-Arm Angulations)
📊 DIAGRAM 4 - C-Arm Projections
CRANIAL (+)
↑
|
LAO (Left) ←──┼──→ RAO (Right)
|
↓
CAUDAL (-)
LAO = Left Anterior Oblique (X-ray tube to RIGHT of patient)
RAO = Right Anterior Oblique (X-ray tube to LEFT of patient)
Standard Coronary Views:
| Projection | Best Visualizes |
|---|
| LAO 45° + Cranial 20° | LAD mid/distal, Diagonal branches |
| LAO 30° + Caudal 20° (Spider) | LM, LAD proximal, LCx origin |
| RAO 30° + Cranial 20° | LAD proximal/mid, Diagonals |
| RAO 30° + Caudal 20° | LCx, Obtuse Marginals |
| LAO 40-60° | RCA body |
| RAO 30° | RCA, PDA |
2.4 Image Playback and Recording
- Cine recording - 15-30 frames per second digital recording
- Fluoroscopy - real-time low-dose X-ray
- Digital Subtraction Angiography (DSA) - background bone/tissue subtracted, only vessels visible
- Road mapping - saved image used as reference while navigating catheter/wire
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CHAPTER 3 - INTRACARDIAC PRESSURES & PRESSURE RECORDING
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3.1 Normal Intracardiac Pressures
📊 DIAGRAM 5 - Heart with Normal Pressures
PULMONARY CIRCULATION
PA: 25/10 mmHg (mean 15)
PV: ~8 mmHg
_______________↑_______________
| |
RA: 2-8 mmHg HEART LA: 6-12 mmHg
| |
RV: 25/4 mmHg LV: 120/8 mmHg
|_____________↓_________________|
AORTA: 120/80 mmHg
(Systemic Circulation)
Complete Normal Pressure Table:
| Chamber/Vessel | Systolic (mmHg) | Diastolic (mmHg) | Mean (mmHg) |
|---|
| Right Atrium (RA) | - | - | 2-8 |
| Right Ventricle (RV) | 15-30 | 0-8 | - |
| Pulmonary Artery (PA) | 15-30 | 4-12 | 9-16 |
| PCWP | - | - | 6-12 |
| Left Atrium (LA) | - | - | 6-12 |
| Left Ventricle (LV) | 100-140 | 4-12 | - |
| Aorta | 100-140 | 60-90 | 70-105 |
3.2 Pressure Recording Systems
Components:
- Catheter (intravascular)
- Connecting tubing (stiff, non-compliant)
- Transducer (converts pressure to electrical signal)
- Amplifier
- Display monitor/recorder
📊 DIAGRAM 6 - Pressure Transducer Setup
PATIENT'S BLOOD VESSEL
|
[Catheter]
|
[Connecting Tubing] ←── Flush system (heparinized saline)
|
[Transducer] ← converts mechanical pressure → electrical signal
|
[Amplifier]
|
[Monitor/Recorder] → Displays waveform
Zeroing the Transducer:
- Place transducer at level of mid-axillary line (phlebostatic axis)
- Open to atmosphere and zero
- This corrects for hydrostatic pressure
3.3 Fluid-filled Catheters vs Catheter-tipped Manometers
| Feature | Fluid-filled System | Catheter-tipped Manometer (Millar) |
|---|
| Cost | Cheap | Very expensive |
| Accuracy | Moderate | High fidelity |
| Frequency response | Low (10-15 Hz) | High (0-10 kHz) |
| Artifacts | Air bubbles, clots, kinks cause damping | Minimal |
| Use | Routine diagnostic | Research, LV dP/dt measurement |
3.4 Artifacts in Pressure Recording
📊 DIAGRAM 7 - Types of Damping
NORMAL WAVEFORM:
/\ /\ /\
/ \ / \ / \
/ \ / \ / \
/ \/ \/ \
OVERDAMPED (Air bubble/clot):
__ __
/ \ / \ ← Peak is blunted/rounded
/ \____/ \ ← Diastolic not accurate
UNDERDAMPED (Ringing/Overshoot):
/\/\ /\/\ ← Spiky, exaggerated peaks
/ \ / \ ← False high systolic
Causes of Damping:
- Air bubbles in tubing
- Blood clot in catheter
- Catheter kinking
- Loose connections
- Catheter against vessel wall
How to Fix Damping:
- Flush catheter firmly
- Aspirate and re-flush
- Rotate/reposition catheter
3.5 Ventriculization
Definition: When the catheter tip is in the pulmonary artery but slips back, the PA pressure waveform changes to look like a ventricular waveform (RV pressure pattern with no diastolic notch).
NORMAL PA WAVEFORM: VENTRICULIZED PA:
__ __
/ \ / \
/ \_____ / \
(diastolic / \___ ← no dicrotic
notch present) notch, diastolic
falls to near zero
3.6 Pressure Gradient Recording
Peak-to-Peak Gradient:
- Measured when catheter is pulled from LV to Aorta
- Difference between LV systolic peak and Aortic systolic peak
- Non-simultaneous measurement
Pull-back Gradient:
- Catheter pulled back slowly from distal to proximal chamber
- Records continuous pressure change
- Used to locate exact site of obstruction in valvular/subvalvular stenosis
📊 DIAGRAM 8 - Aortic Stenosis Gradient
LV PRESSURE: AORTIC PRESSURE:
___ __
/ \ / \
/ \ / \
/ \ / \
\___ \___
|←── GRADIENT ──→|
(LV systolic peak) (Aortic systolic peak)
e.g., 200 mmHg e.g., 120 mmHg
Gradient = 80 mmHg (significant AS)
Grading of Aortic Stenosis by gradient:
- Mild: <25 mmHg
- Moderate: 25-50 mmHg
- Severe: >50 mmHg
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CHAPTER 4 - CARDIAC OUTPUT DETERMINATION
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4.1 Definition
Cardiac Output (CO) = volume of blood pumped by the heart per minute
- Normal: 4-8 L/min
- Formula: CO = Heart Rate × Stroke Volume
Cardiac Index (CI) = CO / Body Surface Area (BSA)
4.2 Thermodilution Method
Principle:
Cold saline injected into right atrium → temperature change detected downstream in pulmonary artery → CO calculated by Stewart-Hamilton equation.
📊 DIAGRAM 9 - Thermodilution Method
SWAN-GANZ CATHETER POSITIONED IN PA:
[RA Port] ──→ Inject 10 mL cold saline (0-4°C)
|
Right Atrium
↓
Right Ventricle
↓
Pulmonary Artery ──→ [Thermistor detects temperature change]
↓
[CO Computer calculates]
↓
[Cardiac Output displayed]
THERMODILUTION CURVE:
Temperature
change |\
| \
| \
| \___________ ← Area under curve is inversely
└────────────── proportional to cardiac output
Time
(Large area = low CO; Small area = high CO)
Stewart-Hamilton Equation:
CO = V × (TB - TI) × K
─────────────────────
∫ ΔTB(t) dt
Where:
V = Volume of injectate
TB = Blood temperature
TI = Injectate temperature
K = Correction factor
∫ ΔTB(t) dt = Area under temperature-time curve
Steps:
- Patient at rest
- Inject 10 mL cold (0-4°C) saline quickly (<4 seconds) into proximal port (RA)
- Computer calculates from temperature curve
- Take 3 readings and average them
- Values should be within 10% of each other
Causes of Error:
- Slow injection
- Wrong injectate temperature
- Tricuspid regurgitation (TR) - gives falsely high CO
- Intracardiac shunts
4.3 Fick Method (Oxygen Dilution)
Principle:
Oxygen consumed by the body equals the difference between oxygen delivered to tissues and oxygen returned from tissues.
Formula:
VO2 (Oxygen Consumption in mL/min)
CO = ─────────────────────────────────────────────────────
(Arterial O2 Content - Venous O2 Content) × 10
Where:
VO2 = O2 consumption (measured or assumed ~125 mL/min/m²)
Arterial O2 content = Hb × 1.36 × SaO2 × 10
Venous O2 content = Hb × 1.36 × SvO2 × 10
📊 DIAGRAM 10 - Fick Principle
LUNGS
↑ O2 added (VO2 = 250 mL/min)
|
Pulmonary Vein (SaO2 = 98%)
↓
HEART → Body
↑
Superior Vena Cava (SvO2 = 70%)
CO = VO2 / (CaO2 - CvO2)
= 250 / (200 - 150) mL/L
= 250 / 50
= 5 L/min
Fick vs Thermodilution Comparison:
| Feature | Fick Method | Thermodilution |
|---|
| Gold standard? | Yes | Common clinical standard |
| Invasiveness | Requires O2 consumption measurement | Less invasive |
| Accuracy in low CO | Better | Less accurate |
| Accuracy in high CO | Less accurate | Better |
| Affected by shunts? | Yes (need modified Fick) | Yes (TR causes error) |
4.4 Principles of Oximetry
How Pulse Oximetry Works:
- Uses Beer-Lambert Law
- Oxyhemoglobin (HbO2) absorbs more infrared light (940 nm)
- Deoxyhemoglobin (Hb) absorbs more red light (660 nm)
- Ratio of absorption at two wavelengths = oxygen saturation
📊 DIAGRAM 11 - Oximetry Principle
RED LIGHT (660 nm) INFRARED (940 nm)
→→→→→→→→→→→ →→→→→→→→→→→
[LED] → Finger → [Detector] [LED] → Finger → [Detector]
Deoxyhemoglobin absorbs Oxyhemoglobin absorbs
more RED more INFRARED
Ratio = R = (AC660/DC660) / (AC940/DC940)
SpO2 calculated from empirical calibration curve
Normal SpO2: 95-100%
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CHAPTER 5 - SHUNT DETECTION AND CALCULATIONS
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5.1 Definition
A cardiac shunt is an abnormal communication between the left and right sides of the heart or great vessels, causing blood to flow in an abnormal direction.
5.2 Types of Shunts
📊 DIAGRAM 12 - Shunt Types
LEFT-TO-RIGHT SHUNT: RIGHT-TO-LEFT SHUNT:
(Acyanotic defects) (Cyanotic defects)
LA ──→ RA (ASD) RA ──→ LA (Severe ASD with PHT)
LV ──→ RV (VSD) RV ──→ LV (Severe VSD with PHT)
Aorta→PA (PDA) Aorta←PA (Eisenmenger)
Oxygenated blood flows RIGHT Deoxygenated blood flows LEFT
Causes: volume overload RV, Causes: CYANOSIS, low O2 sat
pulmonary hypertension (Eisenmenger syndrome)
5.3 Shunt Detection - Step-up Method
Oxygen Saturation Sampling:
Blood samples taken from multiple sites as catheter is advanced:
| Site | Normal O2 Saturation |
|---|
| Superior Vena Cava (SVC) | 70% |
| Inferior Vena Cava (IVC) | 80% |
| Right Atrium (RA) | 72-76% |
| Right Ventricle (RV) | 72-76% |
| Pulmonary Artery (PA) | 72-76% |
| Pulmonary Vein (PV) | 95-98% |
| Left Atrium (LA) | 95-98% |
| Aorta | 95-98% |
Significant Step-up (indicating L-R shunt):
- RA step-up >7% → ASD (L→R shunt at atrial level)
- RV step-up >5% → VSD (L→R shunt at ventricular level)
- PA step-up >5% → PDA (L→R shunt at great vessel level)
📊 DIAGRAM 13 - Oxygen Saturation in ASD
NORMAL ASD (L→R Shunt)
SVC: 70% → RA: 72% SVC: 70% → RA: 85% ← (STEP UP!)
↓ ↓
RV: 74% RV: 85%
↓ ↓
PA: 74% PA: 85%
↑
(LA blood mixing
via ASD)
5.4 Shunt Calculation (Qp:Qs Ratio)
Formula:
Qp SaO2 - MVO2
── = ──────────────────
Qs PVO2 - PAO2
Where:
Qp = Pulmonary blood flow
Qs = Systemic blood flow
SaO2 = Systemic arterial O2 saturation (Aorta)
MVO2 = Mixed venous O2 saturation
PVO2 = Pulmonary vein O2 saturation (or assumed 98%)
PAO2 = Pulmonary artery O2 saturation
MVO2 = (3 × SVC sat + 1 × IVC sat) / 4
Interpretation:
| Qp:Qs | Meaning |
|---|
| 1:1 | No shunt |
| 1.5:1 | Small shunt (usually not significant) |
| 2:1 | Moderate shunt (usually needs closure) |
| >2:1 | Large shunt (definite closure indicated) |
✏️ Model Answer (10 marks):
Q: Explain shunt detection and calculation in cardiac catheterization.
Answer: A cardiac shunt is an abnormal communication between the right and left sides of the heart. In the catheterization laboratory, shunts are detected by the oximetry run (step-up method) and quantified by the Qp:Qs ratio.
Detection: Blood samples are drawn from the SVC, IVC, RA, RV, PA, PV, LA, and aorta. A significant increase (step-up) in oxygen saturation at a particular level indicates a left-to-right shunt at that level. An RA step-up of >7% suggests ASD, RV step-up >5% suggests VSD, and PA step-up >5% suggests PDA.
Calculation: The pulmonary-to-systemic flow ratio (Qp:Qs) is calculated using the Fick principle. A ratio of 1:1 means no shunt; 1.5:1 is borderline; ≥2:1 indicates a large shunt requiring closure.
Clinical significance: A right-to-left shunt causes cyanosis and systemic desaturation, indicating Eisenmenger physiology, which is a contraindication for shunt closure.
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CHAPTER 6 - CORONARY ANGIOGRAPHY
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6.1 Definition
Coronary angiography is an invasive imaging technique where contrast dye is injected into the coronary arteries under fluoroscopy to visualize the coronary anatomy and detect stenosis (narrowing), occlusion, or other abnormalities.
6.2 Coronary Anatomy
📊 DIAGRAM 14 - Coronary Arteries
AORTA
|
Left Main (LM) ──────── RCA (Right Coronary Artery)
/ \ |
LAD LCx Conus Br.
(Left Anterior (Left (Left |
Descending) Circumflex) Circumflex) SA Node Artery
| | |
Diagonal Obtuse Right marginal
branches Marginal |
| branches PDA (Post Descending)
Septal |
perforators AV Node Artery
LAD supplies: Anterior wall LV, anterior 2/3 septum
LCx supplies: Lateral wall LV, posterior wall (if dominant)
RCA supplies: Right ventricle, inferior wall LV (if dominant)
DOMINANCE:
- Right dominant (85%): RCA gives PDA
- Left dominant (10%): LCx gives PDA
- Codominant (5%): Both give PDA
6.3 Coronary Angiographic Catheters
| Catheter | Artery | Approach |
|---|
| Judkins Left (JL 3.5, 4, 5) | LCA | Femoral (default) |
| Judkins Right (JR 4) | RCA | Femoral (default) |
| Amplatz Left (AL 1, 2) | LCA | Femoral (difficult anatomy) |
| Amplatz Right (AR 1, 2) | RCA | Femoral |
| EBU/XB | LCA | Radial approach |
| Barbeau/Tiger | Both LCA & RCA | Radial (single catheter) |
6.4 Use of the Manifold
📊 DIAGRAM 15 - Manifold Setup
MANIFOLD = 4-WAY STOPCOCK SYSTEM
[Pressure Transducer]
|
[Contrast Syringe] ── MANIFOLD ── [Catheter to Patient]
|
[Flush Line]
(Heparinized saline)
|
[Waste/Discard]
FUNCTION: Allows operator to:
1. Flush catheter with saline
2. Aspirate blood (to check catheter position)
3. Inject contrast
4. Monitor pressure
5. Prevent air entry (CRITICAL - air embolism is deadly!)
Steps for Manifold Use:
- Connect all lines and remove all air bubbles
- Flush catheter with saline before entering patient
- Check pressure waveform after catheter enters coronary
- If pressure dampens - DO NOT inject; reposition catheter
- Aspirate blood before injection to confirm no air
- Inject contrast
6.5 Coronary Angiography Views
📊 DIAGRAM 16 - Views for LCA
LCA VIEWS:
RAO Cranial LAO Cranial AP Cranial
(30°/20°) (45°/25°) (0°/25°)
↗ LAD proximal ↗ LAD mid/distal ↗ LAD proximal/mid
↗ Diagonals ↗ Diagonals ↗ Diagonals
RAO Caudal LAO Caudal (Spider) AP Caudal
(30°/25°) (40°/30°) (0°/30°)
↗ LCx, OM branches ↗ LM, LAD/LCx fork ↗ LM, LCx
Views for RCA:
| View | Structures Seen |
|---|
| LAO 40-60° | RCA body |
| RAO 30° | RCA, PDA, posterior branches |
| Left lateral | RCA crux, AV nodal artery |
6.6 Degrees of Coronary Stenosis
NORMAL: |████████████████| 100% lumen
50% STENOSIS:|████████| 50% lumen (not significant*)
70% STENOSIS:|█████| 30% lumen (significant!)
90% STENOSIS:|██| 10% lumen (critical!)
100%/TOTAL :| OCCLUSION
OCCLUSION
*Flow-limiting stenosis: >70% (or >50% in LM)
Reporting Stenosis (TIMI Flow):
| TIMI Grade | Description |
|---|
| 0 | No flow (Total occlusion) |
| 1 | Minimal flow (contrast doesn't clear) |
| 2 | Partial flow (slow filling) |
| 3 | Normal flow |
6.7 Lab Preparation for Coronary Angiography
- Patient prep: NPO 4-6 hours, consent, IV access, pre-medication (antiplatelet, anticoagulant)
- Access site: Radial (preferred) or femoral; local anesthesia
- Arterial sheath inserted (5Fr or 6Fr)
- IV Heparin 5000 units to prevent clotting
- Catheter advanced to coronary ostium under fluoroscopy
- Contrast injected (5-10 mL per injection, hand injection)
- Multiple views recorded
- Sheath removed, hemostasis achieved
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CHAPTER 7 - LEFT VENTRICULOGRAPHY
═══════════════════════════════════
7.1 Definition
Left ventriculography is the angiographic study of the left ventricle by injecting contrast dye into the LV cavity using a power injector to assess wall motion and ejection fraction.
7.2 Catheter Used
Pigtail catheter - standard for LV angiography
- Multiple side holes (12-14 holes)
- Reduces jet effect against LV wall
- Prevents arrhythmia and perforation
- Curled tip prevents direct wall injury
7.3 Standard Views for LV Angiography
| View | What It Shows |
|---|
| RAO 30° | Anterior wall, inferior wall, mitral valve (MR assessment) |
| LAO 60° | Septal wall, posterior-lateral wall |
📊 DIAGRAM 17 - LV Wall Segments in RAO View
LV IN RAO 30° VIEW:
ANTERIOR WALL
|
___________↓___________
/ Antero- | Antero- \
/ basal | apical \
| _______→ APEX |
| | |
\ Infero- Infero- /
\ basal apical /
\_________↑____________/
INFERIOR WALL
Wall segments:
1. Anterolateral
2. Anterior
3. Apical
4. Inferior
5. Inferoposterior/Posterior
Normal: ALL segments contract inward (uniform)
7.4 Wall Motion Abnormalities
| Term | Definition |
|---|
| Hypokinesis | Reduced but present inward movement |
| Akinesis | No movement |
| Dyskinesis | Paradoxical outward movement (bulging) during systole |
| Aneurysm | Permanent outward bulge of LV wall (post-MI) |
| Hyperkinesis | Excessive inward movement (compensatory) |
📊 DIAGRAM 18 - Wall Motion
NORMAL: HYPOKINESIS: AKINESIS: DYSKINESIS:
Systole ↗↖ Systole ↗↖ Systole ─ ─ Systole ↙↘
│ │
Diastole ─ ─ ─ ─
(Arrow = direction of wall motion during systole)
7.5 Ejection Fraction (EF) Calculation
Formula:
EF = (EDV - ESV) / EDV × 100
Where:
EDV = End Diastolic Volume (LV at its largest)
ESV = End Systolic Volume (LV at its smallest)
Stroke Volume = EDV - ESV
Normal EF: ≥55%
Mild dysfunction: 45-54%
Moderate: 35-44%
Severe: <35%
How EDV and ESV are Measured:
- Area-Length method (most common in cath lab)
- Measure LV area in RAO view at end-diastole and end-systole
- Use formula: V = 8A²/3πL
7.6 Power Injector Settings for LV Angiography
| Parameter | Value |
|---|
| Volume | 30-45 mL |
| Flow Rate | 12-14 mL/sec |
| Rise time | 0.3-0.5 sec |
| PSI limit | 600-900 psi |
Complications of LV Angiography:
- Ventricular arrhythmias (PVCs, VT)
- Contrast injection causing staining (subendocardial)
- Perforation (rare, pigtail catheter reduces this risk)
7.7 Mitral Regurgitation Assessment
Grading by LV Angiography (Sellers Classification):
| Grade | Description |
|---|
| 1+ | Faint contrast in LA, clears quickly |
| 2+ | Moderate LA filling, clears in several beats |
| 3+ | Full LA filling = LV density |
| 4+ | Dense LA filling, contrast into pulmonary veins |
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CHAPTER 8 - RIGHT HEART CATHETERIZATION
═══════════════════════════════════
8.1 Definition
Right heart catheterization involves passing a catheter through venous access into the right atrium, right ventricle, pulmonary artery, and wedge position to measure pressures and cardiac output.
8.2 Swan-Ganz (Pulmonary Artery) Catheter
📊 DIAGRAM 19 - Swan-Ganz Catheter
SWAN-GANZ CATHETER (4 lumens):
|──── 30 cm ────|──────── 70 cm ───────────|
| | | |
[Proximal port [Distal [Thermistor [Balloon]
(RA position)] port port] O ← inflate 1.5 mL air
(PA pos.)]
PORTS:
1. Proximal (RA): inject cold saline for thermodilution, CVP monitoring
2. Distal (PA): measure PA pressure and PCWP
3. Thermistor: temperature sensing for CO measurement
4. Balloon: floats catheter forward, wedges in PA branch
POSITION SEQUENCE:
Vein → RA → RV → PA → Wedge (PCWP)
8.3 PCWP (Pulmonary Capillary Wedge Pressure)
Definition: When the balloon is inflated and catheter wedges in a pulmonary artery branch, flow is stopped and the catheter measures pressure transmitted backward through the pulmonary capillaries from the left atrium. It reflects left atrial pressure and left ventricular filling pressure (preload).
Normal PCWP: 6-12 mmHg
Clinical Significance:
| PCWP | Interpretation |
|---|
| <12 mmHg | Normal |
| 13-18 mmHg | Mild LV failure |
| 19-25 mmHg | Moderate LV failure / Pulmonary edema risk |
| >25 mmHg | Frank pulmonary edema |
📊 DIAGRAM 20 - PCWP Waveform
PA PRESSURE: PA WEDGE (PCWP):
__ a v
/ \ __ /\ /\
/ \/ \ / \/ \
/ \____________/ \_____
(Pulsatile PA waveform) (Low phasic PCWP waveform)
Systolic/diastolic a wave = atrial contraction
v wave = ventricular filling
8.4 Procedure - Right Heart Catheterization
Access: Internal jugular (IJV), subclavian (SCV), or femoral vein
Steps:
- Insert sheath into vein under sterile conditions
- Connect Swan-Ganz catheter to pressure monitor
- Inflate balloon with 1.0-1.5 mL air
- Advance catheter - it floats with blood flow:
- RA position → record RA pressure
- RV position → record RV pressure (deflate balloon briefly)
- PA position → record PA pressure
- Wedge position → inflate balloon, record PCWP
- Deflate balloon when in wedge position (to avoid PA infarction!)
- Measure cardiac output by thermodilution
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CHAPTER 9 - RADIATION PROTECTION
═══════════════════════════════════
9.1 Why Radiation Safety Matters
Ionizing radiation in the cath lab comes from the fluoroscopy/X-ray system. Excessive exposure causes:
- Skin erythema and burns (acute)
- Cataracts (lens of eye)
- Cancer (malignancy - long term)
- Genetic damage
9.2 Three Cardinal Principles of Radiation Protection
📊 DIAGRAM 21 - Radiation Protection
╔═══════════════════════════════════════════╗
║ 3 CARDINAL PRINCIPLES ║
║ ║
║ 1. TIME 2. DISTANCE 3. SHIELDING
║ ↓ ↓ ↓ ║
║ Minimize Maximize Use lead ║
║ exposure distance protection║
║ time from source ║
║ ║
║ Dose ∝ Time Dose ∝ 1/D² Lead apron ║
║ (Inverse square ║
║ law) ║
╚═══════════════════════════════════════════╝
1. TIME:
- Radiation dose is directly proportional to time
- Use fluoroscopy only when necessary
- Use last image hold feature (not continuous fluoro)
- Collimate X-ray beam to smallest needed area
2. DISTANCE (Inverse Square Law):
If distance doubles → dose reduces to 1/4
If distance triples → dose reduces to 1/9
Example:
At 1 meter: dose = 100 mR/hr
At 2 meters: dose = 25 mR/hr
At 3 meters: dose = 11 mR/hr
STAND AS FAR FROM X-RAY TUBE AS POSSIBLE
3. SHIELDING:
| Protection Device | Coverage |
|---|
| Lead apron (0.5 mm Pb) | Torso - reduces 90-95% of scatter |
| Thyroid collar | Thyroid gland protection |
| Lead glasses | Eyes - prevents cataracts |
| Leaded gloves | Hands (when near beam) |
| Lead curtain (under table) | Scatter from below table |
| Mobile lead shield | Standing protection for staff |
9.3 Radiation Units
| Unit | Measures | Modern Unit | Old Unit |
|---|
| Exposure | Ionization in air | Coulomb/kg (C/kg) | Roentgen (R) |
| Absorbed Dose | Energy deposited in tissue | Gray (Gy) | Rad |
| Effective Dose | Biological effect on body | Sievert (Sv) | Rem |
| Activity | Radioactive decay rate | Becquerel (Bq) | Curie (Ci) |
Conversion: 1 Sv = 100 rem | 1 Gy = 100 rad
9.4 Dose Limits (ICRP Recommendations)
| Person | Annual Dose Limit |
|---|
| Occupational (radiation worker) | 20 mSv/year (5-year average) |
| Pregnant worker | 1 mSv for entire pregnancy |
| General public | 1 mSv/year |
| Students <18 years | 6 mSv/year |
9.5 ALARA Principle
ALARA = As Low As Reasonably Achievable
- Minimize dose while achieving diagnostic quality
- Use lowest possible fluoroscopy frame rate (7.5 fps instead of 15 fps)
- Collimate (narrow the X-ray beam)
- Use copper filters to reduce low-energy radiation
9.6 Additional Radiation Safety Measures in Cath Lab
X-RAY TUBE (below table)
↓ Primary beam
[PATIENT]
↑ Scatter radiation (most dangerous to staff)
Tips to reduce scatter:
- Keep X-ray tube BELOW table (not above)
- Stand on IMAGE INTENSIFIER side (not tube side)
- Use steep angulations less - more scatter at extreme angles
- Keep II close to patient (reduces scatter and improves image)
═══════════════════════════════════
CHAPTER 10 - ELECTROPHYSIOLOGY (EP) STUDY BASICS
═══════════════════════════════════
10.1 Definition
Electrophysiology (EP) study is an invasive procedure where electrode catheters are placed inside the heart to record intracardiac electrical signals and induce arrhythmias to diagnose and treat them.
10.2 Catheters Used in EP Study
| Catheter | Poles | Placement | Records |
|---|
| HRA catheter | Quadripolar (4 poles) | High Right Atrium | Sinus node activity, atrial signals |
| His Bundle catheter | Quadripolar | Tricuspid valve area | AH interval, HV interval |
| Coronary Sinus (CS) | Decapolar (10 poles) | CS vein (left atrial access) | LA, LV activity |
| RVA catheter | Quadripolar | Right Ventricular Apex | Ventricular signals |
| Ablation catheter | 4-8 mm tip | Target site | Recording + energy delivery |
10.3 Connection of Catheters in EP Study
📊 DIAGRAM 22 - EP Catheter Positions
HEART (posterior view):
┌──────────────────┐
HRA catheter ──────→│ Right Atrium │←── Coronary Sinus (CS)
│ │ catheter (in LA vicinity)
His catheter ──────→│ Tricuspid Valve │
│ area (HBE) │
│ Right │
RVA catheter ──────→│ Ventricle │
└──────────────────┘
EP RECORDING DISPLAY (simultaneous channels):
Ch1: HRA (High Right Atrium)
Ch2: HBE (His Bundle Electrogram) - shows A, H, V deflections
Ch3: CS 1-2 (proximal)
Ch4: CS 9-10 (distal)
Ch5: RVA
Ch6: Surface ECG (I, II, V1)
10.4 His Bundle Electrogram (HBE)
📊 DIAGRAM 23 - HBE Components
HBE SIGNAL:
A H V
___ _ ___
/ \ / \ / \
/ \ / \ / \
/ \__/ \____/ \___
A = Atrial signal (depolarization of atrium near His)
H = His bundle potential (small, sharp spike)
V = Ventricular signal
INTERVALS:
PA interval: P wave to A → intra-atrial conduction (normal: 20-40 ms)
AH interval: A to H → AV nodal conduction (normal: 60-125 ms)
HV interval: H to V → His-Purkinje conduction (normal: 35-55 ms)
HV >100ms = risk of complete heart block
10.5 Arrhythmia Induction - Programmed Electrical Stimulation (PES)
Purpose:
- Induce tachyarrhythmias to diagnose mechanism (SVT, VT, WPW)
- Test effectiveness of medications or ablation
Types:
- Burst pacing - rapid pacing to induce atrial flutter, VT
- Programmed stimulation - basic drive train with 1-3 extra stimuli (S1-S2-S3)
10.6 Radiofrequency Ablation (RFA)
📊 DIAGRAM 24 - RF Ablation Mechanism
ABLATION CATHETER TIP:
___
/ \ ← 4-8 mm tip electrode (active)
│ ● ● │ ← Temperature sensor (37-60°C target)
\___/
|
RF Generator
300-750 kHz
25-50 Watts
MECHANISM:
RF current → resistive heating → tip heats tissue
Temperature 50-60°C → irreversible cell death (necrosis)
Lesion size: 5-7 mm diameter, 3-5 mm depth
Conditions Treated by RFA:
| Arrhythmia | Target Ablation Site |
|---|
| SVT (AVNRT) | Slow pathway near tricuspid valve |
| WPW syndrome | Accessory pathway (Kent bundle) |
| Atrial Flutter | Cavotricuspid isthmus (CTI) |
| Atrial Fibrillation | Pulmonary vein isolation (PVI) |
| VT | Scar-related reentrant circuit |
═══════════════════════════════════
CHAPTER 11 - PACEMAKER FUNDAMENTALS
═══════════════════════════════════
11.1 Definition
A pacemaker is an electronic device that delivers electrical impulses to the heart muscle to stimulate contraction when the heart's natural electrical system fails.
11.2 Indications for Pacing
- Complete (3rd degree) AV Block - No conduction from atria to ventricles
- Sick Sinus Syndrome (SSS) - Sinus node dysfunction
- Symptomatic Bradycardia - HR <40 bpm with symptoms
- Bifascicular/Trifascicular block with symptoms
- Post-MI with persistent heart block
- After cardiac surgery
11.3 Components of a Pacemaker
📊 DIAGRAM 25 - Pacemaker System
PACEMAKER SYSTEM:
[Pulse Generator]
┌─────────────┐
│ Battery │ ← Lithium iodide, lasts 7-10 years
│ Electronic │
│ circuit │
└──────┬──────┘
│ (connector block)
════╪════ Lead wire
│
[Electrode tip]
(in contact with heart muscle)
Types of Leads:
- Unipolar: 1 electrode (tip only)
- Bipolar: 2 electrodes (tip + ring, 1 cm apart)
Bipolar preferred (less noise, less myopotential sensing)
11.4 NBG Pacemaker Code (5 letter code)
📊 DIAGRAM 26 - NBG Code
POSITION: I II III IV V
MEANING: Chamber Chamber Response Rate Multisite
Paced Sensed to Sensing Modulation Pacing
OPTIONS: O O O O O
(O=None) A A T(trigger) R A
V V I(inhibit) V
D(both) D(both) D(T+I) D
COMMON MODES:
VVI = Ventricle Paced, Ventricle Sensed, Inhibited
(paces ventricle; inhibited if native beat sensed)
DDD = Dual chamber paced, Dual sensed, Dual response
(most physiological mode)
VOO = Asynchronous ventricular pacing
(fixed rate, ignores native beats - used in interference)
AAI = Atrium paced, Atrium sensed, Inhibited
(for sick sinus syndrome with intact AV node)
11.5 Temporary vs Permanent Pacing
| Feature | Temporary | Permanent |
|---|
| Indication | Acute complete AV block, post-MI, pre-op | Long-term need |
| Lead type | Temporary, transvenous | Permanent, implanted |
| Generator | External, bedside | Implanted subcutaneously |
| Access | Femoral/jugular/subclavian vein | Subclavian/cephalic vein |
| Duration | Days to weeks | 7-10 years (battery life) |
| Position | Usually RV apex | RV apex or RV septum |
11.6 Pacemaker Malfunction
📊 DIAGRAM 27 - Pacemaker ECG
NORMAL PACED RHYTHM:
Spike → wide QRS
| _______
| / \
↓ / \
─ ↑ ─/─────────────\──────── ↑ ──/───
(pacing spike) (paced (next spike + QRS)
QRS - wide,
LBBB pattern)
FAILURE TO PACE:
─ ─ ─ ─ ─ ─ ─ ─ ← No spikes seen despite bradycardia
(Check battery, connections, lead)
FAILURE TO CAPTURE:
─ ↑ ─ ─ ─ ─ ↑ ─ ← Spikes present but no QRS follows
(Check threshold, lead displacement)
FAILURE TO SENSE (Undersensing):
─ ↑ ↑ ↑ ↑ ← Paces even when native beats present
(Pacemaker does not see native R-wave)
═══════════════════════════════════
CHAPTER 12 - VENTRICULAR ASSIST DEVICES (VAD) - BASICS
═══════════════════════════════════
12.1 Definition
A Ventricular Assist Device (VAD) is a mechanical pump that supports heart function and blood flow in a person who has a weakened heart.
12.2 Intra-Aortic Balloon Pump (IABP)
Mechanism:
- Balloon is positioned in the descending thoracic aorta just distal to left subclavian artery
- Inflates with helium gas during diastole
- Deflates rapidly before systole
📊 DIAGRAM 28 - IABP Working
DIASTOLE (balloon INFLATES): SYSTOLE (balloon DEFLATES):
Aortic arch Aortic arch
│ │
│ BALLOON │ (empty)
│ ╔═════╗ ←INFLATED │ ╔ ╗ ←DEFLATED
│ ║▓▓▓▓▓║ (helium) │ ║ ║
│ ╚═════╝ │ ╚ ╝
│ │
EFFECT OF INFLATION: EFFECT OF DEFLATION:
↑ Diastolic pressure ↓ Systolic aortic pressure
↑ Coronary perfusion ↓ LV afterload (LV works less)
↑ O2 delivery to heart ↓ LV oxygen demand
Benefits of IABP:
- Increases coronary blood flow (diastolic augmentation)
- Reduces cardiac workload (afterload reduction)
- Improves cardiac output by 0.5-1 L/min
Triggering Modes:
| Trigger | Description |
|---|
| ECG trigger | Inflates at T-wave (diastole), deflates at R-wave |
| Pressure trigger | Inflates at dicrotic notch of aortic pressure |
| Pacer trigger | Used in paced rhythms |
Timing:
📊 DIAGRAM 29 - IABP Timing on Aortic Waveform
AORTIC PRESSURE WITH IABP:
___
/ \ Augmented
___ / \ diastolic
/ \ / ↑↑ \ pressure
/ \ / IABP \___
/ \/ inflate \ Assisted
/ DICROTIC \ systole
NOTCH \___
Inflate at: Dicrotic notch (beginning of diastole)
Deflate at: Just before next systole (before next upstroke)
Contraindications to IABP:
- Aortic regurgitation (AR) - IABP worsens regurgitation
- Aortic dissection - risk of extending dissection
- Severe aorto-iliac disease - cannot insert balloon
- Abdominal aortic aneurysm
12.3 Impella Device
- Microaxial flow pump placed across aortic valve
- Draws blood from LV and ejects into aorta
- Provides 2.5 - 5.0 L/min support
- Positioned: LV inlet → Aortic outlet
12.4 Extracorporeal Membrane Oxygenation (ECMO)
- Most powerful support device
- Drains blood from RA, oxygenates externally, returns to aorta
- VA-ECMO (veno-arterial) for cardiac support
- Used in cardiogenic shock, cardiac arrest
═══════════════════════════════════════
🎯 EXAM STRATEGY & HIGH-YIELD SUMMARY
═══════════════════════════════════════
✅ Must-Know for 90%+ Marks
Long Answer Questions (10 marks) - Likely Topics:
- Coronary angiography - procedure, catheters, views, complications
- Cardiac output measurement - Thermodilution and Fick method
- Shunt detection and calculation with Qp:Qs formula
- Intra-aortic balloon pump - mechanism, timing, indications, contraindications
- Sterilization methods in cath lab
- Radiation protection in cath lab
Short Answer Questions (5 marks) - Likely Topics:
- Types of catheters and their uses
- Normal intracardiac pressures
- Pressure damping - causes and correction
- Ejection fraction - definition and calculation
- Manifold - use and importance
- Swan-Ganz catheter - ports and positions
- PCWP - definition and significance
- NBG pacemaker code
- RF ablation - mechanism
- TIMI flow grades
Very Short Answers (2 marks) - Likely Topics:
- Definition of cardiac output (Normal = 4-8 L/min)
- ALARA principle
- Thermodilution injectate temperature (0-4°C)
- Balloon gas in IABP (Helium)
- Normal EF (≥55%)
- Qp:Qs ratio significance (>1.5:1 = significant shunt)
- PCWP normal value (6-12 mmHg)
- Fr size formula (1 Fr = 0.33 mm)
- TIMI 3 flow (normal flow)
- Catheter for LV angiography (Pigtail)
📝 Model Exam Answer Template
For any 10-mark answer, use this structure:
1. Definition (1 mark)
2. Principle/Mechanism (2 marks)
3. Steps/Procedure/Types (4 marks) + Diagram (1 mark)
4. Clinical significance/Complications (1 mark)
5. Conclusion (1 mark)
🗓️ Study Plan (7 Days to Exam)
| Day | Chapters | Focus |
|---|
| Day 1 | Ch 1 & 2 | Catheters, Lab Setup |
| Day 2 | Ch 3 & 4 | Pressures, Cardiac Output |
| Day 3 | Ch 5 & 6 | Shunts, Coronary Angio |
| Day 4 | Ch 7 & 8 | LV angiography, Right heart cath |
| Day 5 | Ch 9 & 10 | Radiation, EP study |
| Day 6 | Ch 11 & 12 | Pacemaker, IABP/VAD |
| Day 7 | Revision | All formulas, diagrams, model answers |
All 12 chapters are now covered with exam-ready answers, diagrams, and model write-ups. Study the diagrams carefully as they carry 1-2 marks each in university exams. Practice writing the formulas (Qp:Qs, Fick, EF, thermodilution) without looking - those are guaranteed marks!
Good luck for your semester exam! You can do it! 🎯