Cardiology: Block 1 Flashcards
In humans, the formation of a linear heart tube from the primary cardiac crescent occurs between days _ and _ of gestation
21 - 23
Looping of the heart tube and trabecular formation of the ventricle occur at day _ of gestation
26
At __ weeks, the embryonic interventricular communication closes, followed by thickening and remodeling of the ventricular walls in the first trimester
6
By the end of week __, heart development is essentially finished, although the heart continues to enlarge throughout gestation
7
What happens during Phase 0 of myocardial contraction?
Depolarization
Na channels open, + Na flow into membrane causing depolarization
Na depolarizes SA Node
What happens during Phase 1 of myocardial contraction?
Brief repolarization
Peak positive point as Na influx slows and stops
K leaks out
Slow voltage Ca channel opens allowing influx and transition to Phase 2
What happens during Phase 2 of myocardial contraction?
Plateau phase
Influx of Ca balances w/ efflux of K
Ca influx initiates troponin and myosin causing contraction and marks the beginning of a contraction
What happens during Phase 3 of myocardial contraction?
Repolarization
Voltage gated K open and allows efflux from cell causing rapid repolarization and includes completion of contraction and relaxation
What happens during Phase 4 of myocardial contraction?
Resting Potential
K is equal intra/extracellularly and allows for resting potential and is ready to receive action potential
Ca inflow/K outflow occurs during Phases _ -_
These phases represent what event?
1-3
Myocardial contraction= QRS complex
What process returns the myocardium to a resting state?
NKAtp
Sodium Potassium Adenosine Triphosphatase
What four processes can cause/lead to myocardial atrophy?
Bed rest
VAD
CA
Weightlessness
What two processes can cause/lead to physiological hypertrophy?
Exercise
Pregnancy
What three processes can cause/lead to physiological hypertrophy?
HTN
MI
Neurhumoral activation
What happens when persistent stress is present on a pathologic hypertrophied heart?
Heart failure
Ventricular arrhythmia
What are the layers of the pericardium?
Fibrous layer
Parietal / Serous- forms sac
Pericardial cavity
Epicardium / Visceral
How much pericardial fluid is contained within the pericardium and where does it come from?
10-20cc formed by the serous layer
What happens if there is too much pericardial fluid?
Pericardial effusion then inflammation
What direction does the heart sit in the chest?
Rotated Left
Tilted forward
R ventricle- most forward
L atrium- furthest posterior
What borders the heart?
Anterior= sternum and L side of costal cartilage 3-5 Post= descending aorta, esophagus, trachea and posterior lungs Lateral= lungs Superior= ascending aorta and superior vena cava
What is a normal PMI diameter?
1 - 2.5cm
What is Erb’s Point best used for hearing?
Aortic/Pulmonic origin
HCM
Aortic insufficiency
What does it mean if a cardiac pulsation is visible lateral to left MCL?
What does a sustained apex impulse mean?
Cardiac enlargement
LVH
On a lateral x-ray, what forms the anterior border?
What primarily forms the posterior border?
Superior- pulmonary trunk
Inferior- right ventricle
Left ventricle, inferior vena cava
Characteristics of S1
Closure of M/T valves (vetricular contraction)
Timed w/ pulse in carotid artery and onset of systole
Heard at 5ICS and critical for maintaining pressure
Hypovolemia induced regurg heard here
Characteristics of S2
Closure of A/P valves
Corresponds w/ onset of diastole- 2/3 and most important part of cycle
Define Physiologic Splitting
Inspiration delayed closing of pulmonic valve preceded by aortic valve closing from the decrease in intrathoracic pressure
Characteristics of S3
Dull/low pitched signaling the filling of ventricles after S2 during diastole and associated w/ lower leg swelling
Most of time= pathologic
Usually caused by: CHF, mitral/tricuspid insufficiency
What is a pathologic finding in S3 called?
Ventricular gallop from volume overload
S1 S2 S3
Slosh ing in
Characteristics of S4
When atria contract late in diastole
Caused by HTN
What is called an Atrial Gallop?
Stiff ventricle noise heard during S4 from pressure overload
a STIFF wall
S4 S1 S2
Right atria received deoxygenated blood from what structures?
Sup/Inf Vena cava
Coronary sinus
Define Atrial Kick
When both atria contract act the end of diastole and correlates w/ S4
What structure in the right ventricle houses/carries the right bundle branch?
Moderator band
How much thicker is the left ventricle than the right?
What else is different about the left ventricle?
3x thicker
Only 2 papillary chordae, more of a sheet of fibers
AV valves open during ?, close during ? and correspond with ?
Diastole
Systole
S1 and pulse in carotid artery
What are the two leaflets of the mitral valve called?
The mitral area is AKA ?
What are the three leaflets of the tricuspid valve called?
Anteromedial/Posterolateral
Apical/Apex
Anterior, Medial, Posterolateral
What causes the semilunar valves to close and in correspondence with ?
Open during systole, close during diastole from backwards pressure
S2
Aortic + pulmonic closing= DUB
What are the 3 cusps of the aortic valve?
What are the 3 cusps of the pulmonic valve?
Right, Left, Non-Coronary cusp
Anterior, Right, Left
When do the papillary move and in what direction?
Pull leaflets down and together at onset of isovolumtetric ventricular contraction to prevent regurgitation
Tears or ischemia of papillary muscles cause regurgitation of ? valve and is often heard during?
Mitral
MI
Where are the ostia that feed the coronary arteries?
When are they supplied w/ blood?
Behind L and R coronary cusps
Fill during diastole
What parts of the heart does the RCA supply blood?
Inf/Post wall of L ventricle R atrium R ventricle Posterior 1/3 of septum SA/AV node
What does the posterior descending artery supply?
Parts of septum
What does the LAD supply blood to?
Anterior 2/3 of septum
Bundle branches
Anterior left ventricle
What does the LCX supply blood to?
SA node (25% of PTs)
Lat/Post L ventricle
L atrium
PDA in 10% of PTs
What is the sequence of events during depolarization and PQRST?
SA node Interatrial/nodal path AV node Junction/His bundle R/BB Ant/Post facicles Purkinje fibers Ventricle
Autonomic nervous system regulates cardiac output through regulation of what 3 things?
SA node pacemaker rate
Myocardial contractility
Vascular smooth muscle tone
(HR, impulse speed, contraction force)
NS that influences the cardiac cycle emerge from what part of the spine and innervate ? structures through ? types of receptors?
T1-5
Meet at cardiac plexus near aorta arch
Innervate through Beta-1 receptors
SA Node, Atria, AV node, ventricles
How does the parasympathetic NS slow the HR/force?
Dorsal motor nucleus to vagus nerve to the SA node, Atria, AV node and Ventricles
What is the equation for CO?
CO= SV x HR
SV- volume ejected w/ each contraction
HR- number of beats/min
Define Preload
Load that stretches heart muscle prior to contraction (ventricle wall tension at end of diastole)
What are the 4 components of preload?
Total volume
Distribution of blood
Atrial contraction
Compliance
How is CO measured?
Ventricle end diastolic volume
Ventricular end diastolic pressure
Directly measured during left heart catheterization
Estimated during right heart catheterization through pulmonary capillary wedge pressure
Define Afterload
What two factors determine it?
Force that the left ventricle has to pump against
Aortic pressure- mean BP
Volume of ventricular cavity and thickness of ventricular wall
What factors influence aortic pressure?
Define Law of LaPlace
Peripheral vascular pressure
Blood volume
Afterload increases, SV and CO decrease
What 3 mechanisms contribute to the regulation of HR?
Autonomic NS
Bainbridge reflex response to atrial stretch
Thoracic pressure changes during respiration of venous return
What 5 physiological things can affect the heart?
Hypoxia Hypercapnea Ischemia/Infarct Acidosis ETOH
What are the Hs and Ts?
Hypovolemia Hypoxia H+ excess Hypoglycemia Hyperkalemia Hypothermia
Tension Pneumo
Tamponade
Toxin
Thrombosis
Narrow QRS’ is a ? problem
Wide QRS’ is a ? problem
Mechanical/RV
Metabolic/LV
Define the Bainbridge Reflex
Response to atrial stretching
Baroreceptors cause increased HR
Inc HR allows body to redistribute blood volumes
How is primary cardiac function assessed?
Ejection Fraction
Fraction of end diastolic volume ejected from ventricle ejected during systolic contraction (55-75%)
Ejection fraction can’t be directly measured, how is it estiimated?
Nuclear ventriculography Echo MRI Gold Standard= cardiac catheterization EF=SV/end diastolic volume
What are the two acute and chronic mechanisms for compensation?
Acute= Frank Starling, Sympathetic Stimulation
Chronic= Ventricular Hypertrophy/Dilation
Define Frank Starling Mechanism
Relationship between stroke volume and end diastolic pressure
SV increases in response to increased volume of blood in the ventricle before contraction
What does the Frank Starling curve estimate?
What is the difference between inotrope and chronotripics?
CO vs Preload
Inotrope- alter contractions
Chrono- alter HR
Done w/
Lect 1
Why are PA and Lateral Chest x-rays ordered?
When should the be ordered?
Structure/function of heart, lungs, and great vessels
Nearly every PT with potential cardiac presentation within 30min
What are the primary indications of getting a CT scan for cardiac PTs?
Suspected great vessel problems including aortic aneurysm/dissection in a stable PT
Pericardial abnormalities
CT scans of the heart, when indicated, can be used to evaluate what four things?
Great vessels
Pericardium
Myocardium
Coronary arteries
What is the main use for Electron Beam CT Scanners?
Evaluate pericardial disease and cardiac tumors
Define Agatstan Score and it’s use
When CT scan is performed correctly, score is achieved and correlates w/ atherosclerotic plaque burden and considered a cardiac risk predictor
What are the benefits and limitations of newer generation CT scanners?
Benefits- quick, less invasive than angiography, inexpensice
Limits- contrast dye, significant radiation exposure, artifacts from movement, no degree of stenosis present
MRI is AKA? and best used for ?
Cardiovascular magnetic resonance
Differentiating tissues w/out contrast
What are the indications for ordering a CMR?
Same as CT but w/ greater potential to evaluate function, perfusion, viability, tissues, blood flow and morphology
Define CMRA
Cardiovascular magnetic coronary angiography
Sensitive/accurate for CAD in LMCA and proximal midpoints of 3 coronary vessels
Congenital coronary abnormalities
What is the use of a MRI w/ contrast?
Gadolinium used to find infarcted area to distinguish between reversible and non-reversible areas
What are the two purposes of US imaging?
Cardiac structures- M, 2D, 3D
Blood flow
What are the two types of US?
Trans-Thoracic Echo- transducer placed in PT chest wall to obtain images but can be impaired by habitus
Trans-esophageal Echo- transducer placed in esophagus by endoscope
What are the indications for ordering an Echo?
Valvular lesions- quantify regurg/stenosis
Assess ventricles- thickness, masses, ejection fraction, function
CAD- wall motion post MI, R ventricle function quality
Cardiomyopathy
Pericardial disease
What type of info do TTEs offer?
Estimated ejection fraction Assess LV for RV dilation L atrium size Paradoxical septal motion Blood flow direction
What test would be ordered to assess the severity of a valve obstruction from calcification?
Continuous wave Doppler
What advantages do a TEE offer?
Increased sensitivity and specificity for anatomic abnormalities- aortic dissections, endocarditis, prosthetic valve dysfunction, LA thrombus prior to cardioversion
TTE or TEE can be performed with simultaneous venous saline agitation in order to ID ?
This test is called a ?
Intracardiac Shunt
Bubble study
What is the pattern/sequence of viewing structures with a TEE?
Mitral valve and L chambers Aortic valve Left atrial appendage R side structures Interatrial septum Base of heart Transgastric area Aorta
Normal HR ?
P wave duration ?
50-100bpm
<0.12 sec
PR interval length
QRS duration
90-200msec
75-110msec
QTc for males and females
QRS axis
390-450/390-460
-30 - +90
Normal heart beat ranges for newborn, 2y/o, 4y/o and 6+y/o
New= 110-150 2= 85-125 4= 75-115 6= 60-100
What type of BBB is more dangerous and needs immediate evaluation?
Isolated LBBB- 2x increased risk of CV event/dying from cardiovascular cause
What nuclear medicine test is ordered to assess left ventricle function?
MUGA- multi-unit gated acquisition, AKA RVG
Images blood passing through heart and great vessels Locate areas of ischemia
Assess myocardial metabolism
What nuclear medicine test is ordered to assess myocardial perfusion?
PET- positron emission tomography
What is the primary purpose of a Radionuclide Ventriculography?
Left or right ventricle ejection fraction by radiolabeling RBCs w/ T-99m
What are the advantages and disadvantages of a RVG study?
Highly accurate, info in RV and LV simultaneously, no habitus limitation, less than 30min
Radiation exposure, no info on valves, less accurate in PTs w/ arrhythmia
How does a PET Scan of the heart work and what info is provided?
Assessment of myocardial perfusion and viability from N-13, Fl-18 or Ru-82 uptake that is proportional to blood flow
Viability assess from radionuclide sugar solution
What test is used to identify areas of impaired blood flow or injured myocardium?
PET Scan
When are PTs requested to wear holter monitors?
Suspected frequent, recurrent arrhythmia
What test is usually ordered first for PTs with frequent/daily Sxs like palpitations or unexplained syncope or dizziness?
oolter monitor
Continuous ECG monitoring in the inpatient setting is called?
Telemetry
What are the uses and benefits of an event monitor?
AKA Loop Monitor, worn for 3days-3wks with ECG recording triggered by the PT and provides increased diagnostic yield
Used in PTs w/ infrequent arrhythmia-type Sxs of in PTs w/ non-diagnostic holter monitor eval
When is an implantable loop recorder used?
PTs w/ infrequent but concerning Sxs that suggest a pathologic arrhythmia ie, unexplained syncope
What type of ambulatory monitoring would be most appropriate for PTs with intermittent palpitations that occur every 1-2wks?
Wearable defib vest
What are the three types of cardiac stress tests?
Treadmill exercise stress test
Treadmill stress imaging- echo or nuclear
Pharmacological stress testing
What is the diagnostic principle and primary goal of stress testing?
Inducing stress increases O2 demands that can induce EKG changes
Determine likelihood of clinically significant underlying CADz
What are the four purposes of a cardiac stress test?
Prognostic assessment
Functional capacity assessment
Determine therapy effectiveness
Evaluate exercise induced arrhythmia
What are absolute contraindications to ALL stress testing modalities?
STEMI 2 days or less High risk ACS- perform coronary angiogram HF- decompensated Current endocarditis Aortic stenosis Sx HOCWhatM Myo/pericarditis Physically disabled and prevents safe/adequate testing
Define Bayes’ Theorem and whom it works best for
Probability of PT having a disease after Dx test is completed is related to Dz probability before the test and the probability that the test provides a true result
Intermediate pre-test probability
Define High, Intermediate and Low probability of CAD
High= +85% +40men/+60women w/ anina and risk factors (DM, smoking, hyperlipidemia) Intermediate= 15-85%, -40/-60y/o w/ possible angina Low= <15%, possible angina in PTs w/out combination of risk factors
What baseline EKG abnormalities preclude ECG base testing?
What happens if a test is conducted with these issues present?
LBBB, paced rhythm, non-specific IVCD
Any ST depression >1mm
LVH or digoxin therapy w/ any ST depression
WPW
High false positive
What is the most common treadmill protocol for exercise stress tests?
Bruce protocol- requires PT reaches 85% of max HR
Sensitivity= 60-65%
Specificity= 80-85%
Exercise stress tests are conducted until one of what three events occur?
Angina
Signs of MI on ECG
Max HR is reached
PT is fatigued
Stress tests are used to assess what ?
Risk of CV event Long term prognosis Exercise capability Therapeutic decision making Localize ischemia areas for treatment
How are abnormal cardiac stress tests defined?
Clinical parameters- index chest pain
Electrical parameters- ST depression of 1mm or more
Both
“Markedly” positive cardiac stress test findings include?
Ischemic ECG findings withing 3min or persist for 5m after test ST depression >2mm SBP decreases during exercise Ventricular arrhythmia PT unable to exercise for 2min
Define Duke Prognostic Treadmill Score
3 variables used to estimate prognosis after an exercise treadmill test
What findings indicate an adverse prognosis for PTs other than their Duke Score?
ST depression/severe angina <6min ST depression >2mm in 5 or more leads ST elevation w/out prior Q waves DBP dec by 10mm Sustained VT or complex PVCs HR dec <12bpm in first minute of recovery is strong indicator of cardiac mortality Inability to reach 85% of max HR
What drug is used for cardiac stress test in PTs unable to exercise for a Stress Echo?
IV infusion of Dobutamine (cardiac inotrope)
What drugs are used for stress tests in PTs that are unable to exercise for Nuclear Stress Myocardial Perfusion Study?
Thallium
Dobuamine
Adenosine/Dipyridamole- induce coronary artery dilation like exercise w/out increasing HR
What is the gold standard for invasive cardiac measurements?
Cardiac catheterization- most commonly performed catheterization type to evaluate potential CAD
What are the therapeutic indications for a Left Heart Catheterization?
Balloon angioplasty and stent to treat CAD
Intra-aortic balloon pump for cardiogenic shock
Balloon valvuloplasty for valvular stenosis
Percutaneous closure of intracardiac shunts
Define a Left Cardiac Catheterization
Define a Right Cardiac Catheterization
Femoral/brachial or Axillary artery access to ascending aorta and left ventricle and atrium
Subclavian/internal jugular/brachial/femoral vein w/ Swan-Ganz catheter w/out requirement for fluoroscopic guidance
What measurement approximates the pressure at the left atrium?
Wedge Pressure
Inc= wet, volume overload
Dec= dry, volume depletion
What type of PT usually gets right sided heart catheterization?
Critically ill w/ complex hemodynamics that can’t be assessed by bedside methods
What are the indications for ordering a right sided heart catheterization?
Assess filling pressure/output in PTs w/ HF
Assess volume status/resistance in PTs w/ sepsis
Evaluate intra-cardiac shunts
Evaluate pericardial disease
Peri-op monitoring PTs w/ high risk of HF during procedure
What are the indications for ordering an electrophysiological study?
Analysis of recurrent/difficult to manage arrhythmias
Assess pharmaceutical/implant device efficiency
Ablation of recurrent arrhythmias that are unresponsive to medical therapy
Done w/
Lect 2
The central physiological role of the heart is closely intertwined with what five other disciplines?
Surgery Hematology Immunology Nephrology Endocrinology
What are the 4 parts to the clinical approach in cardiology?
Anatomic abnormalities
Physiologic abnormalities
Underlying etiology
Functional disability
What are the cardinal Sxs?
Dyspnea Palpitations Syncope Edema Claudication Fatigue
What is the atypical presentation of an atypical AMI?
Female, Elderly, DM, CHF
No chest pain, localized pain in neck, back, jaw or head
What is the most common Sx of heart disease?
How is it determined to be of cardiac or non-cardiac origin?
Dyspnea
OPQRST
Stopped on
Slide 41 Lect 3
What are the indications for ordering an electrophysiological study?
Analysis of recurrent/difficult to manage arrhythmias
Assess pharmaceutical/implant device efficiency
Ablation of recurrent arrhythmias that are unresponsive to medical therapy
Done w/
Lect 2
The central physiological role of the heart is closely intertwined with what five other disciplines?
Surgery Hematology Immunology Nephrology Endocrinology
What are the 4 parts to the clinical approach in cardiology?
Anatomic abnormalities
Physiologic abnormalities
Underlying etiology
Functional disability
What are the cardinal Sxs?
Dyspnea Palpitations Syncope Edema Claudication Fatigue
What is the atypical presentation of an atypical AMI?
Female, Elderly, DM, CHF
No chest pain, localized pain in neck, back, jaw or head
What is the most common Sx of heart disease?
How is it determined to be of cardiac or non-cardiac origin?
Dyspnea
OPQRST
Stopped on
Slide 41 Lect 3
Location, Quality, Duration, Worse/Better, S/Sxs of ANgina
L: retrosternal; radiates to neck, jaw, arm, shoulder
Q: pressure/burn/squeeze/heavy
D: 2-10min
A/R: exercise, cold, stress / rest, nitro
S/Sxs: S3 or papillary muscle dysfunction murmur during pain episode
Location, Quality, Duration, Worse/Better, S/Sxs of Rest or Unstable angina
L: same as angina Q: same as angina but more severe D: <20min A/R: same as angina, dec tolerance for exertion/at rest S/Sx: transient heart failure can occur
Location, Quality, Duration, Worse/Better, S/Sxs of MI
L: substernal, radiates similar to angina
Q: heavy, pressure, burning, burning, constriction
D: >30min, but variable
A/R: unrelieved by nitro/rest
S/Sx: N/V, SoB, sweating, weak
Location, Quality, Duration, Worse/Better, S/Sxs of Pericarditis
L: over sternum/apex, radiates to neck or L shoulder
Q: sharp, stabbing, knife-like
D: hrs to days w/ waxing/waning
A/R: deep breath, rotating chest, supine / sitting, leaning
S/Sxs: friction rub (best heard LLD)
Location, Quality, Duration, Worse/Better, S/Sxs of Aortic Dissection
L: anterior chest, radiates to back Q: excruciating, tearing, knife-like D: sudden and unrelenting A/R: HTN, Marfan Syndrome S/Sxs:aortic murmur, HTN, BP asymmetry, large/displaced PMI
Location, Quality, Duration, Worse/Better, S/Sxs of PE
L: substernal or over site of PE Q: pleuritic or angina-like D: sudden onset, lasts minutes-hrs A/R: breathing worsens it S/Sxs: tachy, dyspnea, Signs of RVFailure
Location, Quality, Duration, Worse/Better, S/Sxs of PHTN
L: substernal Q: pressure, oppressive D: similar to angina A/R: worse w/ effort S/Sxs: pain w/ dyspnea, signs of PHTN
What are the key terms associated with the quality of pain for non-cardiac causes of chest pain?
Pneumo w/ pleurisy- pleuritic, local Spot Pneumo- sharp, very local MSK d/o- ache Herpes- burning, itch Esophageal reflux- burning, visceral discomfort Ulcer- visceral burning, ache Gallbladder- visceral Anxiety- variable and transient
What kind of peripheral findings will be noted with an arterial or venous
Arterial- diminished/absent pulse, infection, pain, cold to touch
Vein- rarely diminished pulse, swelling, pain, warm to touch
What peripheral S/Sx is seen in PTs with CHF?
3rd spacing- pitting edema
Clubbing in fingers is indicative of ?
Chronic hypoxia
