cardiac electrophysiology

Question 1

name the valves and where they are

Answer 1

tricuspid -> right side
mitral -> left side
aortic
pulmonary -> anterior, on the outer part

Question 2

name two used imaging techniques

Answer 2

intravascular ultrasound (IVUS) and optical coherence tomography (OCT)

Question 3

name a few approaches that focus on the heart valves, left auricle, and septal defects

Answer 3

• transcatheter aortic valve replacement
• mitral valve repair or replacement
• closure of permeable foramen ovale
• closure of left atrial auricle

Question 4

three types of valves that can be implanted

Answer 4

• self expandable
• balloon expandable
• mechanically expandable

Question 5

what does electrophysiology focus on?

Answer 5

on the electrical system of the heart and the diagnosis and treatment of:
- bradycardia (<60bpm)
- tachycardia (>100bpm)
- arrhythmias (irregular)

Question 6

what is the disadvantage of lead pacemakers?

Answer 6

leads can break, and hard to remove because tissue grows around them -> now, leadless pacemakers placed directly in ventricle

Question 7

how many people survive until hospital admission for tachycardia (sudden cardiac death)

Answer 7

10%
only 5% can continue old work and tasks

Question 8

what does ICD stand for?

Answer 8

implantable cardioverter defibrillator

Question 9

what are the different lead configurations for ECG?

Answer 9

Einthoven: bipolar, 4 extremity leads

Goldberger: unipolar

Wilson: 6 or 9 chest electrodes

Combination to get 12 lead ECGs

Question 10

what is catheter ablation?

Answer 10

destroy some cells -> creates tiny scars in the heart that block faulty electrical signals and restore the heart rhythm

Question 11

electro-anatomic mapping: goal?

Answer 11

visualize propagation

electrical mapping = see how early or late the electrial signal is picked up

anatomical mapping = reconstruction of cavity of interest

Question 12

two technologies for catheter visualization / tracking (one issue with the first one)

Answer 12

1) impedance based: externally applied electrical current results in voltage gradient -> very sensitive to sweat for example

2) sensor-based: voltage is induced when relative motion exists between a conductor and a magnetic field

Question 13

different modalities of energy transfer for ablation

Answer 13

1) thermal:
- radiofrequency
- high intensity focused ultrasound
- laser
- cryotherapy

2) non-thermal: pulsed field ablation -> keep E field low to not kill surrounding tissue

Question 14

how can we verifiy contact between catheter and tissue for effective heat transfer during ablation? (two techonologies)

Answer 14

1) deformation dependent force measurement (spring technology, or optical)

2) impedance based

Question 15

basics of cryablation

Answer 15

• Cooling of non ideal gas when slowly expanded from high pressure to lower pressure (Joule-Thomson effect)
• cell dehydration