Cardiovascular Genetics

Question 1

Electrical Function of Heart

Answer 1

• electrical impulse/action potential generated at regular intervals in sinoatrial node in right atrium
• action potential spread over atria resulting in contraction
• atrial action potential reaches atrioventricular node and conducts impulse
• impulse passed along by Purkinje fibers and bundle of His leading to contraction of ventricles

Question 2

Electrocardiogram

Answer 2

• aka ECG/EKG

- study used to record electrical activity of heart using electrodes attached to skin

Question 3

Anatomy of Action Potential

Answer 3

P wave = atrial activation
PR interval = time from onset of atrial activation to onset of ventricular activation
QRS complex = ventricular activation
QRS duration = duration of ventricular activation
ST-T wave = ventricular repolarization
QT interval = duration of ventricular activation and recovery

Question 4

Exercise Stress Test

Answer 4

EKG monitored while patient walks on treadmill or pedals on stationary bike and speed and incline/resistance increased

Question 5

Holter Monitor

Answer 5

battery operated portable device that measures and records EKG continuously for 24hrs+ while patient keeps diary of symptoms

Question 6

Echocardiogram

Answer 6

• test that uses ultrasound waves to visualize heart
• transthoracic echocardiogram (TTE): most common form and non-invasive
• transesophageal echocardiogram (TEE): probe containing ultrasound transducer passed into patient’s esophagus for clearer visualization of heart

Question 7

Cardiac MRI

Answer 7

uses magnets and radio waves to capture clear images, including soft tissues of heart

Question 8

Ejection Fraction

Answer 8

measurement of blood ejected from LV with each heart beat

Question 9

Heart Catheterization

Answer 9

invasive test that involves insertion of catheter into chamber/vessel of heart for evaluation or other procedures (pulmonary arterial pressure, myocardial biopsy)

Question 10

Pacemaker

Answer 10

electronic device implanted to provide electrical impulses to regulate heart beat

Question 11

Automatic Implantable Cardioverter Defibrillator (ICD)

Answer 11

electric device that is implanted to monitor for and correct cardiac arrhythmia in individuals at risk for sudden cardiac death

Question 12

Ventricular Tachycardia

Answer 12

fast, abnormal heart rate starting in heart’s lower chambers (3+ beats in a row at a rate of >100bpm)

Question 13

Polymorphic Ventricular Tachycardia

Answer 13

ventricular rhythm at rate greater than 100 beats per minute with continuously varying QRS complex morphology

Question 14

Ventricular Fibrillation

Answer 14

heart quivers instead of pumping due to disorganized electrical activity in ventricles and results in cardiac arrest

Question 15

Palpitations

Answer 15

sensation of having fast-beating, fluttering, skipping, or pounding heart

Question 16

Syncope

Answer 16

fainting, temporary loss of consciousness, may be related to insufficient blood flow to brain

Question 17

Heart Failure

Answer 17

heart not pumping sufficiently to deliver oxygen-rich blood to body resulting in fatigue and structural heart changes

Question 18

Sudden Cardiac Death

Answer 18

• death from abrupt loss of heart function
• 95% cases due to structural disease (coronary artery disease/heart attack included), 5% due to nonstructural causes (heart rhythm abnormalities)

Question 19

Aortic Dilatation

Answer 19

diameter of aorta exceeding >/=1.96 std from normal diameter

Question 20

Aortic Aneurysm

Answer 20

local dilation of vessel exceeding 50% of normal size

Question 21

Aortic Dissection

Answer 21

tear in interior layer of aorta, causing inner and middle layers of aorta to separate

Question 22

Arterial/Vessel Tortuosity

Answer 22

vessels with abnormal amounts of twists and turns

Question 23

Mitral Valve

Answer 23

valve that allows blood to flow between left atrium and ventricle

Question 24

Mitral Valve Prolapse

Answer 24

bulging of one or both mitral valve leaflets backward into left atrium when heart contracts (can allow blood to leak back through valve)

Question 25

Beta-Blockers

Answer 25

medications that block effects of hormone epinephrine, resulting in heart beating more slowly and with less force, reducing blood pressure

Question 26

Implantable Cardioverter Defibrillator (ICD)

Answer 26

• battery-powered device placed under skin, connected by wires to heart
• if abnormal heart rhythm detected, device delivers electric shock to restore normal heartbeat

Question 27

Congenital Heart Disease

Answer 27

• abnormality of cardiovascular development leading to structural/functional problems
• most common congenital anomaly (1-2% of live births)

Question 28

Congenital Cardiovascular Disorders

Answer 28

• aneuploidy: Turner, T13, T18, T21
• microdeletions: Williams, Alagille, 22q11.2
• single gene variants: Alagille, CHARGE, Holt-Oram, Kabuki, RASopathy spectrum
• metabolic disorders: GSD, LSD, FAOD, OA, MPS, sitosterolemia, SLOS
• mitochondrial disorders: MELAS, MERRF, Barth syndrome
• muscular dystrophies: LGMD, DMD, BMD, female DMD carriers, myotonic dystrophy
• connective tissue disorders: TAAD, Shprintzen-Goldberg syndrome, congenital contractural arachnodactyly, Marfan, Loeys-Dietz, vascular EDS

Question 29

Cardiomyopathies

Answer 29

• hypertrophic
• dilated
• restrictive
• non-compaction
• arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC)

Question 30

Arrhythmias/Channelopathies

Answer 30

• long QT syndrome
• Jervell and Lange-Nielsen syndrome
• Timothy syndrome
• Andersen-Tawil syndrome
• Brugada syndrome
• short QT syndrome
• catecholaminergic polymorphic ventricular tachycardia (CPVT)

Question 31

Aortopathies

Answer 31

• familial isolated TAAD
• Marfan syndrome
• Loeys-Dietz syndrome
• vascular EDS
• Williams syndrome
• Turner syndrome

Question 32

Other Hereditary Cardiovascular Conditions

Answer 32

• familial hypercholesterolemia
• amyloidosis
• pulmonary arterial hypertension