Cardiopulmonary I Flashcards
What forms the heart Apex?
Left Ventricle
The base of the heart is the _____ and found _____
Top
2nd Costal cartilage
The anterior of the heart is mostly
Rt Ventricle
Heart dimensions:
5 long
3.5 wide
2.5 thick
Fist
Right ventricle:
Left ventricle:
pulmonary circulation
systemic circulation
What is the depression in the inter-atrial septum called?
Fossa ovalis
remnants foramen ovale
What is a failure to form the Fossa Ovalis called?
Patent foramen ovale
Define:
Atrial septal defect
Inter-atrial septum forms incorrectly
Heart:
top?
bottom?
Base
Apex
What are the most common Congenital abnormalities of the heart?
Ventricular septal
How can a VSD (ventricular septal defect) be acquired?
Myocardial infarction and scar formation by macrophage
Healthy heart ejects _____ of what fills it.
1/2
What defines ventricular volume?
End Diastolic Volume
What defines output?
Stroke volume
Ejection fraction =
SV/EDV (x100%)
What are the 3 tissue layers of the heart wall?
Endocardium
Myocardium
Epicardium
What is found between the Epicardium and the Parietal Pericardium?
Pericardial space
10 mL fluid
The Myocardium isn’t capable of Hyperplasia, but is capable of…
hypertrophy
Nuclei in cardiac cell?
Mononucleated
although many have 2
What is another name for the Visceral Pericardium?
Epicardium
What important feature of the heart is considered part of the Epicardium?
Epicardial Fat
Epicardial Fat:
% surface?
% total weight?
Where found?
60-80
20
generally along vasculature
What are 2 functions of the Pericardial Space?
Heat dissipation
Lubricant
4 Heart valves:
2 atrioventricular
2 semilunar
What is backflow called in the heart?
Regurgitation
What valve lies between the right atrium and right ventricle?
Tricuspid Valve
T/F
The tricuspid valve is smaller in diameter and thicker than the mitral valve.
False
larger diameter, thinner than Mitral
What valve lies between the left atrium and left ventricle?
Mitral (bicuspid) valve
What are the atrial ventricular valves attached to?
From where do they originate?
Chordae Tendineae
“heart strings”
Papillary muscles
When do the papillary muscles contract the chordae tendineae?
As Ventrical contracts
prevents valve from prolapsing and folding in on itself
The Pulmonic and Aortic are both ______ valves and have ___ cusps.
Semilunar
3
What is the term for Ventricular filling?
Diastole
What makes the Lub and Dub sound?
Lub - Tricuspid and Mitral (atrioventricular) valves shutting
Dub - Semilunar (Pulmonic, Aortic) shutting
What 3 structures empty into the Right Atrium?
Superior vena cava
Inferior vena cava
Coronary Sinus
What is the 4th outer layer of the heart?
Parietal Pericardium
What are 3 ways acute pericarditis manifests?
Chest pain (can be sharp) Friction rub ECG changes
What is the term for exudate between the Visceral and Parietal Pericardium?
Pericardial effusion
*this compresses the heart wall
A clear pericardial effusion associated with SLE, rheumatic fever, and viral infections is called?
Serous Pericarditis
A fibrin rich exudate in the pericardial sac caused by uremia, MI, or acute rheumatic fever is called?
Fibrinous Pericarditis
What type of pericarditis has a cloudy exudate?
Purulent
What type of Pericarditis has a bloody exudate?
Hemorrhagic pericarditis
A swelling of the Pericardial sac can cause what medical emergency?
What is the remedy?
Cardiac Tamponade
Pericardiocentesis
What are the 2 major forms of disorders arising from within the heart tissue (myocardium)?
*excluding cardiovascular disease
Myocarditis (inflammation)
Primary Cardiomyopathies
non-inflammatory, cardiomegaly
What drug can cause myocarditis?
cocaine
What are 3 types of Primary cardiomyopathies?
Dilated
Hypertrophic
Restrictive
T/F
Cardiomyopathies often occur without any mitigating pathology
True
What is the most common form of Primary cardiomyopathy?
Dilated
What is a Dilated Cardiomyopathy?
affects?
*common complication?
**caused by?
Ventricular Hypertrophy
pumping
*Mural thrombi
**alcohol
What cardiomyopathy could be congenital and is defined by hypertrophy of the ventricles and impaired diastolic filling?
Hypertrophic Cardiomyopathy
What can Hypertrophic Cardiomyopathy cause?
Outflow Obstruction of Left Ventricle
What is the least common Primary Cardiomyopathy?
Restrictive
What defines Restrictive Cardiomyopathy?
Heart regular shape, but stiffened
What condition affects the endocardial surface?
Infective Endocarditis
What 2 factors lead to infective endocarditis?
What organism is involved?
In what other population does it develop?
Damaged surfaces
Portal of entry
S. aureus (50% cases)
IV drug users
What valve is most often associated with Infective Endocarditis?
Mitral
What is the Penicillin analog?
What are the alternatives if allergic?
Amoxicillin
Cephalexin, Azithromycin, Clarithromycin
Where are Terminal Cisternae?
Border of T-tubules - begin the Sarcoplasmic Reticulum
Thick filament:
3 components of thin filament:
Myosin
Actin, Tropomyosin, Troponin `
T/F
Acetylcholine is is the neurotransmitter in the heart.
False
Electrical conduction itself propels
Where do the 2 sources of Calcium in a muscle cell come from?
Sarcolemma/T-tubules
Sarcoplasmic Reticulum
What does Calcium bind to in the muscle cell?
Troponin C
on actin filament
What dictates the magnitude of contraction in a cardiac cell (myocyte)?
Amount of Calcium
T/F
Sarcoplasmic reticulum is more dense in cardiac muscle (vs skeletal).
False
Less dense - needs Calcium from two sources
Intercalated Discs and gap junctions allow the myocardium to act as a:
Functional Syncytium
What 3 Proteins make up the cardiac troponin complex?
cTn = Cardiac Troponin
C (cTnC) - Calcium
I (cTnI) - Inhibitory
T (cTnT) - Tropomyosin binding
What causes both Angina and Myocardial Infarction?
Chief difference between them?
another?
Ischemia
No cell death in Angina
(also, MI not remedied by NTG)
What is the preferred blood marker that indicates cardiac injury?
How long do they stay in the blood?
Cardiac Troponins
(Troponin I or T)
2 hrs - 8 days (peaking at 12-24 hrs)
Trace cardiac conduction starting at the SA node.
SA > Interatrial Tracts
or
Internodal Tracts > AV node > AV Bundle > R/L Bundle Branches > Purkinje Fibers
Where do Non-Pacemaker “Fast Response” action potentials take place?
Atria
Ventricles
Purkinje Fibers
Where do Pacemaker “Slow Response” action potentials take place?
SA/AV node
Fast response in the heart involves ___ and ____ in and _____ out.
Na and Calcium
K
How does Calcium affect the Action Potential in the heart?
Long Lasting (L-type)
Caused by Ca++ channels
T/F
Calcium is an absolute requirement in the Cardiac muscle.
True
Calcium from where does not promote actin-myosin interaction?
What does this trigger?
Sarcolemma Action Potential
*Sarcoplasmic Reticulum Ca++ binds actin
**Calcium induced Calcium release
What receptor releases Calcium from the sarcoplasmic reticulum?
Ryanodine Receptors (RyR2)
What do Beta blockers (and Ach) do to calcium conductance?
Decrease
What does repolarization of heart cell involve?
Efflux K+
L-type Ca++ closes
What happens in the very last phase of cardiac action potential?
Calcium re-uptake
and K+ remain open
What 3 ways is Ca++ extruded from the heart cell?
Sarcoplasmic Reticulum Ca pumps (SERCA)
Sarcolemmal Ca pumps
3Na/1Ca pump (NCX)
Why is Tetani impossible in the heart?
Electrical and mechanical overlap
No summation or tetanus possible
Effective (absolute) vs. Relative refractory period
Effective: no AP possible
Relative: AP possible only if stumulus big enough
Why does the SA node exhibit automaticity?
Unstable RMP
How does Phase 0 differ in the SA node compared with Purkinje, etc?
Calcium conductance, not influx Na+, causes
SA node, what causes:
Slow depolarization (phase4)?
Upstroke (Phase0)?
repolarization (Phase3)?
Na (current called If)
Ca
K
Where is conduction velocity the fastest?
Purkinje
Where is CV the slowest?
What does this allow?
AV node
Ventricular filling
What do chronotropic effects refer to?
firing SA node
What is a negative chronotropic effect?
Decrease SA node
What type of effect changes velocity of conduction in the heart?
Dromotropic
negative - decreases conduction
What type of receptors interact with ACh?
What type?
Muscarinic
parasympathetic
What receptors sympathetically innervate the heart?
Beta1-receptors
norepinepherine
Parasympathetic has a _____ chronotropic effect
Mechanism?
Negative Decrease If (inward Na current in phase 4 slow depolarization step)
Parasympathetic has a _____ dromotropic effect
Mechanism?
Negative
decrease Ca in and increase K out
What is the mechanism of positive chronotropic effect?
*Sympathetic
Increases If conduction in phase 4 depolarization
more Na in
What is the mechanism of positive dromotropic effect?
Increase Ca influx current
T/F
Lead = Electrode
False
Lead defines a space over which electrical signal is measured
Lead II is recorded between what?
Right Arm and Left Leg
What are the main components of the Basic Electrocardiogram?
P wave
QRS complex
T wave
What is happening at the P wave?
QRS?
T wave?
SA node fires (and atrial contraction)
ventricular depolarization
Ventricular repolarization
What are Latent Pacemakers?
AV node
Purkinje fibers
Where does Phase 4 depolarization happen fastest and slowest?
SA node > AV node > purkinje fibers
What is Overdrive Suppression?
Because SA node fastest it supresses the latent pacemakers
What is contraction/emptying of heart?
Relaxation/filling?
Amount of blood pumped out?
Beats/min.
Systole
Diastole
Stroke Volume
Heart Rate
Heart Rats x Stroke Volume =
What should this equate to
Cardiac Output
*normally = venous return
Blood in either Ventricle after Diastole?
End Diastolic Volume
Blood in either ventricle after Systole?
End Systolic Volume
EDV-ESV=
Ejection Fraction
What are the 3 phases of ventricular filling?
Rapid passive
Slow passive
Atrial systole
What produces the 3rd heart sound?
Rapid passive filling
What produces the 4th heart sound?
Atrial systole
What produces the 1st heart sound?
Shutting of mitral valve in Atrial Systole
What produces the 2nd heart sound?
Aortic semilunar valve shuts
What does the Dichrotic Notch in the Wigger’s Diagram represent?
Backflow and reverb in aorta
*significant for coronary blood flow
Where do the heart sounds come from? S1: S2: S3: S4:
mitral/tricuspid valve closure
semilunar valve closure
Rapid Passive Filling
Atrial Contraction
What 2 types of valve problems can murmurs indicate?
Incompetent (swishing)
Stenotic (click)
Define:
Valvular Stenosis
Valvular incompetence
Valve doesn’t open
Valve doesn’t close
*results in myocardial hypertrophy
What are three risk factors for valvular heart disease?
Rheumatic fever
Congenital
Prosthesis
How long after Strep pyogenes infection can Rheumatic fever hit?
1-4 weeks
*Group A B-hemolytic
Tiny warty beadlike rubbery vegetations on the valve leaflets:
They result from?
Most often affects?
Verrucae
Rheumatic heart disease
Mitral valve
What is the most common heart valve problem?
Mitral Valve Prolapse
*7% population, most often young women
What can Aortic Stenosis lead to?
LV hypertrophy
Three main causes of Aortic Stenosis:
4 causes Aortic insufficiency (backflow)
Birth defect (only 1 or 2 cusps)
Rheumatic
Age-related degenerative calcific aortic stenosis
+Infective Endocarditis (aortic insufficiency)
Chronotropic:
SA node
What sympathetically innervates the SA node, atria, AV node, and ventricles?
T1-T4
T/F
Thyroid Hormones can decrease heartbeat
False
T3 and T4 elevate HR
T/F
Hyperkalemia and Hypokalemia can both decrease Heart Rate
True
*K+
What are3 factors affecting Stroke Volume?
Preload (EDV)
Inotropism (contractile force)
Afterload (in Aorta)
What Law defines Preload?
Frank-Starling Law of the Heart
What type of Stroke Volume control depends on how much the LT fills?
Heterometric regulation
What effect does stretch in the heart have on the cell?
Enhances troponinC affinity for Calcium
*more force
T/F
Contractile Force in independent of Preload (Starlings Law).
True
T/F
The Sympathetic system has a negative inotropic effect
False
increases contractile force
Regulation by Inotropism is called…
Homometric
What 2 cellular mechanisms does SNS B1 andrenergic affect to increase contraction (Inotropism)?
Increases Calcium current
Increases SERCA pumps
Where does Afterload occur?
Back pressure on Aortic and Pulmonary Semilunar Valves
Increasing the Afterload is analogous to increasing the…
Blood pressure
*will decrease stroke volume
What drug decreases Afterload?
NitroGlycerine
Ohm’s Law:
Q = P/R
2 Branches off Right Coronary Artery:
Right Marginal (Acute) Posterior Descending (Inter-ventricular)
2 Branches off Left Coronary Artery:
Circumflex
Left Anterior Descending (Inter-Ventricular Artery)
How does coronary resistance change in response to the Sympathetic response?
Dilates vessels
What drives blood into the coronary aa.?
Aortic pressure (dichrotic notch)
When the heart’s demand for blood/oxygen is Greater than supply, you have…
Ischemic Heart Disease
What is episodic chest pain caused by inadequate oxygenation of the myocardium?
Angina Pectoris
What causes Classic/Exertional Angina?
Coronary obstruction
What type of Angina is caused by spasms of the coronary arteries?
this is related to what?
When can this occur?
Variant/Prinzmetal’s/vasospastic
mostly related to coronary artery stenosis
Can occur at rest
What does Unstable Angina refer to?
Plaque disruption
What causes ischemic death of myocardial tissue?
M.I. - Myocardial infarction
What type of MI kills cells through the entire thickness of the ventricular wall?
What MI kills only interior 1/3 of cells?
Transmural Infarction
Subendocardial infarction
Artery occlusion that kills the following regions in MI’s.
Anterior
Lateral
Posterior
Left Anterior Descending
Left Circumflex
Posterior Descending Branch
5 complications to MI:
Arrhythmia (most common cause of death) Pump failure Rupture Papillary muscle rupture Mural thrombosis (endocardium over infarct)
What is the balloon inflation technique of revascularizing the coronary arteries?
other (relatively) non-invasive technique?
PTCA - percutaneous transluminal coronary angioplasty
Stenting
Grafting technique to get around occlusion in coronary artery?
CABG - coronary artery bypass grafting
Heart failure refers to:
Failure of pump
What can dyspnea (difficulty breathing) and orthopnea (shortness of breath) indicate?
Heart mechanically overloaded
Rt and Lt ventricles have same pathologies with exception of pulmonary edema(Lt) and systemic edema(Rt)
ECG sign of Sinus Tachycardia
P and T waves running into each other
What are looong breaks between PQRST?
Sinus Bradycardia
What if the Atria aren’t contracting on ECG?
No P wave
QRS spike wide and running into T:
Ventricular Escape Rhythm
(Purkinje fibers running show)
No P because atria not contracting
What will a premature atrial contraction (PAC) look like on ECG?
inverted P wave
What will Atrial Fibrillation look like?
What causes?
Erratic - but with Ventricular Spikes
Multiple myocytes signalling
ECG with single group of Ventricular myocytes signalling.
PVC - premature ventricular contraction
Irregular looking QRS
What does ventricular fibrillation look like ECG?
Caused by?
sin wave
Multiple Ventricular Myocytes signaling
Big space between P wave and QRS:
1st degree AV block
*often slowed by scarring
Second degree AV block on ECG:
No QRS - skips beat
Wide QRS with regularly spaced P:
Purkinje firing
3rd degree AV block
What can correct a 3rd Degree AV block?
Pacemaker
