cardio quiz 3

atrial diastole

what is happening in the regions marked A

atrial systole

what is happening in the regions marked B

Ventricular diastole

what is happening in the regions marked C

Ventricular systole

what is happening in the regions marked D

60-100 bpm, positive P wave in lead II, 1 P for every QRS

features of normal sinus rhythm

tachycardia

a condition where the heart beats faster than 100 beats per minute

Bradycardia

a condition where the heart beats slower than 60 beats per minute

sinus bradycardia

a type of arrhythmia characterized by a heart rate of less than 60 beats per minute, with a regular rhythm and normal P waves

Sinus tachycardia

a type of arrhythmia characterized by a heart rate of more than 100 beats per minute, with a regular rhythm and normal P waves arrhythmia

3rd degree block/bradycardia

a type of heart block where there is no relationship between the atrial and ventricular rates, leading to a slow heart rate, URGENT CAN BE FATAL

infranodal AV block

a type of heart block that occurs below the AV node, WIDE QRS , potentially LETHAL

atrial fibrillation

most common pathologic arrhythmia, no p waves

Atrial flutter

saw tooth flutter waves, narrow QRS

ventricular tachycardia

a fast heart rhythm originating from the ventricles, typically characterized by dominant wide QRS complexes and can lead to Vfib or cardiac arrest

ventricular fibrillation

quivering ventricle,no effective contraction, life-threatening without immediate CPR and defibrillation

Na in

what is happening in phase 0

K out

what is happening in phase 1

Ca in, K out, myocyte contraction

what is happening in phase 2

K out

what is happening in phase 3

Na/K pumps stabilize resting potential, K in, Na out

what is happening in phase 4

gap junctions

what allows for fast current transduction between myocytes

excitation-contraction coupling

is the physiological process where an electrical stimulus leads to muscle contraction, primarily in cardiac muscle.

phase 2

at what phase of action potential is excitation reaction coupling happening

SA/AV action potential has NO rapid Na influx

difference between action potential of SA/AV nodes and action potential of regular cardiomyocytes

fewer mitochondria, fewer myofibrils, smaller SR

why do SA and AV conduct slower than a regular cardiomyocyte

His bundle, R and L bundle branch, and purkinje fibers

what allows for uniform synchronous contraction of the heart

cell diameter, gap junctions, magnitude and kinetics of depolarizing current

factors that determine cardiac conduction velocity

no summation or tetany

importance of refractory period

norepinephrine

neurotransmitter affecting SA node and AV node, increasing heart rate

acetylcholine

neurotransmitter that decreases heart rate by acting on the SA node and AV node.

epinephrine

neurotransmitter that affects AV node, increasing AV node conduction

high vagal/PSNS tone, endurance athlete, SA node dysfunction

possible causes of sinus bradycardia

patients may be on blood thinners, could increase bleeding risk

why is atrial fibrillation important for dentist to know

coumadin/warfarin, prevents clots formation in left atrium

What particular medication are most people with atrial fibrillation on and why?

syncope

is a temporary loss of consciousness caused by a decrease in blood flow to the brain, often resulting from a drop in blood pressure.

atrial depolarization/ atrial contraction

what is represented by the P wave

time of conduction through AV node

what is represented by the PR interval

ventricular depolarization/contraction

what is represented by the QRS wave complex

time between end of ventricle firing and repolarization

what is represented by the ST interval

ST

during which interval is ischemia and /or infarction most clearly seen

ventricular repolarization

what is represented by the T wave

purkinje fibers

fastest conductors of signal transduction in thee heart

AV node

slowest conductors of signal transduction in the heart

coordinated contraction

why must the purkinje fibers conduct signals quickly

SA node, AV node, bundle of His, R/L bundle branches, purkinje fibers

route of signal transduction in the heart

filling of ventricles

what does depolarization at the AV node allow for

decreased filling of ventricles

what is the result of an elevated heart rate of 200 bpm

prolonged PR interval

abnormal slowing of conduction in the AV node will result in what ECG abnormality?

1st degree heart block

prolongation at AV node, prolonged PR, Asymptomatic

angina

a type of chest pain caused by reduced blood flow to the heart muscle (ischemia), often triggered by physical exertion or stress

narrow QRS complex

a finding on an ECG that means electrical signal originated above ventricles

wide QRS complex

a finding on an ECG indicating the electrical signal originate somewhere in ventricle, BAD

assess stroke risk to determine degree of anticoagulation necessary

what is the purposee of CHA2DSVASC scoring system

CHF (congeestive heeart failure), Hypertension, Age (≥75), diabetes, stroke, vascular disease, age (65-74), and sex (female)

what does CHA2DS2-VASc stand for/look at

2

what CHA2DS2-VASc/ CHADS2 score indicated high risk of embolic stroke

warfarin, DOACs (dabigatran, rivaroxaban, apixaban)

common anticoagulants used for patients at risk of stroke

R atrium, R ventricle, SA and AV nodes

heart regions supplied by right coronary artery

L atrium, L ventricle, AV node (10% of pop)

heart regions supplied by left coronary artery

ischemia

a condition characterized by INSUFFICIENT OXYGEN AND NUTRIENTS to tissues, often leading to tissue damage or necrosis, REVERSIBLE

infarction

cell death as a result of prolonged ischemia, IRREVERSIBLE, results in scar

diaphoresis (cold sweat), fatigue, chest pain

symptoms of ischemia

stable angina

angina that occurs predictably with exertion or stress and is relieved by rest or nitroglycerin

unstable angina

chest pain that occurs at rest, medical emergency, IMPENDING INFARCTION

STEMI

complete coronary artery blockagee/occlusion, must be treated immediately

catheterization/stent placement or by-pass

treatments for STEMI

NSTEMI

incomplete coronary artery blockage, positive myocardial markers

unstable angina is negative for myocardial markers

difference between unstable angina and NSTEMI

troponin

best lab marker for diagnosis of myocardial infarction

NSTEMI

ECG with no ST elevation, ST depression sometimes

STEMI

ECG shows ST elevation

Tissue plasminogen activator

A thrombolytic agent used to dissolve blood clots in conditions like myocardial infarction.

shared pathways with branches of vagus and thoracic nerves

why might cardiac pain be felt in the mandible

atherosclerosis

A condition characterized by the buildup of plaque in the arterial walls, leading to narrowed arteries and reduced blood flow, often contributing to cardiovascular diseases.

coronary arteries

where is atherosclerosis located that leads to myocardial infarction

damage to endothelium, cholesterol buildup, plaque hardens, plaque rupture/blood clot formation

process of atherosclerosis plaque formation

blood clot formation

result of atherosclerotic plaque rupture

cell death and scar formation

what reaction happens in the heart after an area has been infarcted

cell death, neutrophil invasion, macrophage cleanup, and scar formation

how does body respond to infarcted tissue

4-10 days (7 days)

time of maximal weakness of heart tissue after an MI

mural thrombus

blood clot formation in wall of artery or heart chamber that can lead to obstruction of blood flow or embolism

atherosclerosis

number 1 cause of coranary artery disease

unstable atherosclerotic plaque

a type of plaque that can rupture, leading to thrombosis and acute coronary syndromes.

stable atherosclerotic plaque

a type of plaque that is LESS likely to rupture, gradual growth and vessel narrowing

thrombus formation and potential heart attack

what happens when lipid pool of thin-capped atherosclerotic plaque ruptures into the lumen of the vessel

surface of plaque erodes

how does stable plaque result in thrombus development and lead to myocardial infarction

stroke or bleeding

major risks for fibrinolytic agents (TPA)

beta-blockers and nitroglycerin

common anti-anginal medications used in ACS (acute coronary syndromes)

aspirin and P2y12 inhibitor

common antiplatelet medications used in ACS (acute coronary syndromes)

heparin

common anticoagulation medication used in ACS (acute coronary syndromes)

unstable angina, NSTEMI, and STEMI

examples of acute coronary syndromes (ACS)

oxygen demand/supply, coronary blood flow, myocardial oxygen consumption

What are the determinants of myocardial ischemia?

arrhythmias, cardiogenic shock, stroke

complications of MI that can happen within FIRST FEW DAYS

ventricular septal rupture, LV wall rupture, ischemic MR, papillary muscle rupture, pericarditis

what are complications after MI that can happen with first 2 WEEKS

SCAD (spontaneous coronary dissection)

a condition where a tear forms in the coronary artery wall, leading to reduced blood flow and potential heart attack.

first degree block

degree of AV block with prolonged PR interval, not complete block

2nd degree type 1 (nodal)

AV block in which signal has PROGRESSIVE difficulty traversing the AV node, dropped QRS

2nd degree type 2 (infranodal)

AV block with WIDE QRS, stable PR, abruptly dropped QRS

sinus tach, Afib, and Aflutter

examples of narrow QRS complex tachycardias

ventricular tachycardia and ventricular fibrillation

examples of wide QRS complex tachycardias