Cardio Anatomy Questions Flashcards
What are the three muscular sheets of the intercostal muscles?
Intercostalis externa, internus, and intimus
What is the nerve supply to the intercostal muscles?
Corresponding intercostal nerves (ventral ramus of a thoracic nerve)
What is the blood supply to the anterior upper six intercostal spaces?
Branches of internal thoracic artery
What is the blood supply to spaces 7-9 anteriorly?
Branches of musculo-phrenic artery
- Additional Information: The lower two spaces (10-11) are devoid of anterior intercostal arteries
What is the posterior intercostal blood supply to the upper two spaces?
Superior intercostal arteries
What is the posterior blood supply to spaces 3-11?
Descending thoracic aorta
What ribs is the heart located between?
2-5
What is another name for the visceral layer of serous pericardium?
Epicardium
During a surgery, the surgeon must ligate the arterial end to control hemorrhage. Which sinus would be used in order to do so?
Transverse Sinus
- Additional Information: space separating the arterial and venous ends of the heart
What is the function of the auricles?
Increase atrial volume
What is the name of the structure that encircles the junction of the atria and ventricles?
Coronary sulcus
What type of muscles line the atria?
Pectinate muscles
What ridges the walls of the ventricles?
Trabeculae carneae
- Additional Information: Papillary muscles project into the ventricular cavities
Which vessel leaves the right ventricle?
Pulmonary trunk (Pulmonary arteries)
Which vessel leaves the left ventricle?
Aorta
What is responsible for anchoring the AV Valve cusps to papillary muscles?
Chordae tendineae
Which valves prevent backflow into the atria when the ventricles contract?
Atrioventricular valves (AV Valves) – Include tricuspid on right on mitral on left
Which valves prevent backflow into the ventricles when the ventricles relax?
Semilunar valves (aortic and pulmonary)
Blood begins in the right atrium and passed through what valve to enter the right ventricle?
Tricuspid valve
The most common cause of infective endocarditis in IV drug users is S. aureus. Which valve is most frequently involved?
Tricuspid valve
From the right ventricle, how does blood flow through the heart to get to the lungs?
Right ventriclepulmonary semilunar valvepulmonary trunkpulmonary arteries Lungs
From the lungs, blood travels through the pulmonary valves into the left atrium. How does blood return to systemic circulation?
Left atriumbicuspid valveleft ventricleaortic semilunar valveaorta systemic circulation
Which circuit, pulmonary or systemic, is shorter?
Pulmonary
Which circuit, pulmonary or systemic, is higher pressure?
Systemic
Which coronary artery supplies the whole right atrium, most of the right ventricle, and posterior inferior 1/3 of ventricular septum?
Right coronary artery
What is the nerve supply to the heart?
Cardiac plexus (sympathetic and parasympathetic fibers)
A patient presents with a wide pulse pressure and machinery type murmur. What is the suspected diagnosis?
Patent Ductus Arteriosus (PDA)
What node generates impulses for the heart?
SA (sinoatrial) node
The impulses through the heart pause at what node?
AV (atrioventricular) node
What conducts impulses through the interventricular septum?
Bundle branches of His
What depolarizes the contractile cells of both ventricles?
Purkinje fibers
What defines orthostatic hypotension?
> 20 mmHg decrease in SBP or > 10 mmHg decrease in DBP
- Additional Information: If heart rate increases by 15 bmp, decreased circulatory volume is likely the cause of the orthostatic hypotension
What medication has been proven to prolong a patient’s life when they have been diagnosed with coronary disease? What is the mechanism of action?
Beta blockers
Mechanism of action: (i) Decreased oxygen demand due to the reduction in heart rate, blood pressure, and contractility, and the consequent relief of ischemic chest pain.
(ii) Increases threshold of ventricular fibrillation
Digoxin, a class V antiarrhythmic drug, works in what way?
Direct action on cardiac muscle. Indirect action on cardiovascular system via autonomic nervous system.
- Additional Information: Used in supraventricular tachycardia (SVT)
Adenosine, a class V antiarrhythmic drug, works in what way?
Slows conduction through AV Node
- Additional Information: Used in supraventricular tachycardia (SVT)
Amiodarone is what type of drug?
Potassium channel blocker – prolongs action potential – Antiarrhythmic Class III
A patient has irregularly irregular heartbeat. This heart rhythm is the most common cause of what?
Atrial fibrillation – most common cause of embolic CVA (stroke)
- Additional Information: Recall CHADS2 Criteria
Congestive heart failure (1 pt); Hypertension (1 pt); Age > 75 (1 pt); Diabetes Mellitus (1 pt); S2 Stroke, TIA, Thrombus (2 pts)
High risk and warfarin therapy recommended: >2 points; Moderate risk and warfarin or aspirin: 1 point; Low risk and no treatment or aspirin: 0 points
This disease is genetic in nature, more common in Asian men, and causes syncope, ventricular fibrillation, and sudden death (often during sleep).
Brugada syndrome
Loop diuretics leave patients more susceptible to problems with what, than do thiazide diuretics?
Electrolytes
Diuretics can increase susceptibility to what disease, which is identified by negatively birefringent crystals?
Gout, by increasing uric acid levels
A 47 year old woman has been treating her HTN with lisinopril for 15 years. In
the past, she has only experienced a cough which she dealt with knowing that the drug helped her
HTN. However, she presents today to the ED with symmetrically swollen lips and no history
that indicates this is an allergic reaction. What do you believe is the cause and can she be placed
on an ARB instead? What alternative medicines can she be given?
Lisinopril (an ACE-I) is the likely cause. No ARBs due to cross reactivity.
Alternative medicines include diuretics (HCTZ), channel blockers, or beta blockers.
Because of the negative inotropic effects of calcium channel blockers, who should
they be used cautiously in?
Answer: Patients with cardiac dysfunction
Describe the 5 classes of anti-arrhythmic drugs.
I – Sodium channel blockers (decrease conduction velocity)
- Ia: Quinidine, procainamide – prolong repolarization
- Ib: Lidocaine, phenytoin – shortens repolarization
- Ic: Flecanide – minimal effect on repolarization, widens QRS
II – Beta blockers (propranolol, metoprolol, esmolol)
III – Potassium channel blockers
IV – Calcium channel blockers (Non-dihydropyridines, verapamil, diltiazem) V – Others: Adensoine
Contraction of heart muscle is known as what?
Systole
The volume of blood pumped by each ventricle in one minute is known as what?
Cardiac output
Cardiac Output = Heart rate x Stroke Volume
How is stroke volume defined?
End diastolic volume – End systolic volume
What three man factors affect stroke volume?
Preload (degree of stretch of cardiac muscles before contraction), contractility (contractile strength at a given muscle length), and afterload (pressure that must be overcome for ventricles to eject blood)
What does hypertension do to afterload?
Increases it
How is end diastolic volume defined?
Volume of blood in each ventricle at the end of ventricular diastole
How is ejection fraction defined?
(Stroke Volume / End Diastolic Volume) x 100
A normal ejection fraction is usually greater than what percentage?
55-60%
What might you hear on physical exam in a patient with congestive heart failure?
S3 heart sound
On an EKG, what does the P wave correspond to?
Depolarization of the SA Node
On an EKG, what does the QRS complex correspond to?
Ventricular depolarization
On an EKG, what corresponds to ventricular repolarization?
T Wave
On an EKG, what corresponds to atrial repolarization?
Nothing. It is masked by the larger QRS complex.
Is the QRS narrow or wide with bundle branch blocks?
Wide (> 0.12 seconds) because of slower conduction
What leads reveal bundle branch blocks?
V1 and V6
- Additional Information:
Left BBB: RsR’ in V6; deep S in V1
Right BBB: rSR’ in V1; wide S wave in V6
A new left bundle branch block on EKG is highly suspicious for what?
A new MI
What EKG finding may be found in patients with long-standing hypertension?
Left ventricular hypertrophy
V1 or V2 leads: Deep 2 wave; V5 or V6: Tall R wave
V1 (S) + V5 (R) > 33 mm represents LVH
On EKG, what two leads are considered when determining if there is right or left axis deviation?
Leads I and AVF
In normal sinus rhythm, which lead is it normal to have an inverted P wave?
aVR
What is the first line treatment for a patient with symptomatic bradycardia?
Atropine
- Additional Information: Because excess vagal stimulation is the cause of most bradycardia rhythms, anticholinergic atropine is 1st line.
An ECG reveals a “saw tooth” pattern. What is this known as?
Atrial flutter
What is the treatment for tosades de pointes?What is the treatment for tosades de pointes?
IV Magnesium
What is the ECG finding in acute pericarditis?
Diffuse ST Elevation
What is the length of the PR interval in a first degree AV block?
> 0.20 seconds
Which type of AV block causes a constant/prolonged PR interval, resulting in a dropped QRS, which is managed with a permanent pacemaker?
Mobitz Type II
Which 2nd degree AV block causes the PR interval to gradually increase before a QRS is dropped?
Wenckebach (Mobitz Type I)
You note a large diphasic P wave with a tall initial component in Lead II. What does this mean?
Right atrial hypertrophy
- Additional Information: Leads II and V1 are checked for P wave morphology to reveal left or right atrial enlargement.
A patient’s EKG shows a widened QRS and peaked T waves. What electrolyte is likely too high?
Potassium – Hyperkalemia
You suspect an infarction in the inferior leads. What vessel(s) is/are the most likely cause?
Right or left coronary artery (seen in leads II, III, AVF)
What percentage of blood passively flow into the ventricles during ventricular filling in mid-to-late diastole?
80%
During ventricular systole, what is the state of all valves?
Closed – isovolumetric contraction phase
Valves on which side of the heart close first?
Left
Valves on which side of the heart open first?
Right
Valves on which side of the heart close last?
Right
The S1 sound of the heart is caused by closure what which valves?
AV Valves (mitral first, then tricuspid)
In a right bundle branch block, the S1 is split due to delay in closure of which valve?
Tricuspid
A physiologic split of S2 is heard during inspiration due to what?
Increased output of right heart delaying closure of the pulmonic valve
You hear a fixed split S2 when listening to a patient’s heart. What do you suspect?
ASD – atrial septal defect
True or False? An S3 is normal in children and young adults?
True
What causes an S3 sound?
Rapid filling of a very compliant ventricle
The atrium contacts against a stiff ventricle, producing what sound?
S4
Which two sympathetic hormones result in increased excitability, increased contraction force, and increased heart rate?
Epinephrine and Norepinephrine
What hormone causes decreased excitability, decreased contraction force, and decreases heart rate?
Acetylcholine (secreted by vagus nerve) – Parasympathetic system
- Additional Information: Therefore, anti-cholinergic drugs increase heart rate. Vagal maneuvers slow down the heart rate.
Where does the aorta arise from?
Left ventricle
The right and left coronary arteries are branches of what structure?
Ascending aorta
What are the three layers of arterial walls?
Tunica intima, media, and externa
What type of arteries (elastic, muscular, arterioles, or capillaries) are the large vessels, such as the pulmonary trunk and aorta?
Elastic arteries
What vessels are responsible for total peripheral resistance?
Arterioles
What layers of arterial lining are NOT present in capillaries?
Tunica media and externa
What structures bypass the capillary bed?
Arteriovenous anastomoses – direct connections between arterioles and venules
What substance are capillaries normally NOT permeable to?
Plasma proteins
What are the three main factors that influence blood pressure?
Cardiac output, total peripheral resistance, and blood volume
Long-term control of blood pressure is supplied by what?
Renal regulation through the renin-angiotensin system
What two brain structures contain the vasomotor center?
Medulla and pons
Where are baroreceptors located?
Carotid sinuses, aortic arch, walls of large arteries in neck and thorax.
Decreased arterial pressure, detected by the kidneys, results in the secretion of what?
Renin
Renin is converted into what substance by an enzyme from the liver?
Angiotensin I (converted by angiotensinogen)
- Additional Information: Angiotensin I is then converted to Angiotensin II by an enzyme in the lungs (ACE).
Angiotensin II causes what reactions that increase arterial pressure?
Renal retention of salt and water, vasoconstriction, and inactivation of angiotensinase
The inferior vena cava (IVC) collects blood from where in the body?
Inferior to the diaphragm
What is true of the tunica media in veins, compared to arteries?
Thinner
As you age, what happens to hematocrit levels?
Decrease
A 20 year old woman reports that when walking back from class during the winter months, the tips of her fingers become cold and white. What is the name of this disorder?
Raynaud’s disease
A patient present with a throbbing headache localized to her right temple, with blurry vision, and polymyalgia rheumatica. What is the most likely diagnosis?
Temporal arteritis
What is the most common vasculitis?
Temporal arteritis
A 24 year old male who has smoked 1 pack per day since he was 14 year old presents with lower extremity claudication and a right toe ulceration. Given his smoking history and presentation, what is the most likely diagnosis?
Thromboangitis Obliterans (Buerger’s disease)
Which direction does lymph flow?
Towards the heart
Lymph is delivered into one of two large ducts. What are the names of these two ducts?
Right lymphatic duct and thoracic duct
- Additional Information: The right lymphatic duct drains the right upper arm and right side of the head and thorax. The thoracic duct drains the rest of the body.
Where does the thoracic duct arise from?
Cisterna chyli
- Additional Information: Cisterna chyli is a dilated sac at the lower end of the thoracic duct into which lymph from the intestinal truck and two lumbar lymphatic trunks flow.
What are the two main varieties of lymphoid cells?
T and B cells
What is the largest lymphoid organ?
Spleen
What two important points differentiate the thymus from other lymphoid organs?
Functions strictly in T lymphocyte maturation and does not directly fight antigens
- Additional Information: The thymus stops growing during adolescence and then gradually atrophies
What does MALT describe?
Mucosa-associated lymphatic tissue.
Includes: peyer’s patches, tonsils, and the appendix in the digestive tract. Lymphoid nodules in the walls of the bronchi.
True or false? The embryonic digestive tract is non-functional.
True
In fetal circulation, how does blood pass from the pulmonary trunk to the aorta?
Ductus arteriosus
In fetal circulation, how does blood pass from the right to left atrium?
Foramen ovale
What causes the foramen ovale to close?
Pressure from increased blood flow to the left side of the heart
- Additional Evaluation: Functional closure of the foramen ovale and ductus arterosus occurs soon after birth.
Arterial thickening of small arteries and arterioles is called what?
Arteriosclerosis
Lipid deposition and intimal thickening of large and medium sized arteries is called what?
Atherosclerosis
What are the four main stages of the response-to-injury hypothesis that explains the development of atherosclerosis and thrombus?
- Chronic endothelial injury
- Accumulation of lipoproteins and oxidize in the tunica intima
- Smooth muscle cell proliferation and formation of fibrous cap
- Unstable plaque
If the SA node fails, what automaticity foci in the atria may take over pacing?
AV junction (called junctional rhythm)
What is the inherent rate of the SA node?
60-100 beats per minute
What is the inherent rate of the AV junction?
40-60 beats per minute
What is the inherent rate of ventricular ectopic foci?
20-40 beats per minute
What is a normal QT interval?
0.2-0.4
- Additional Information: To account for QT differences at different rates, the QTc is corrected. Normal QTc is < 0.44
What does a long QT interval put a person at risk of?
Tachyarrhythmias
Which genetic disorder is associated with coarctation of the aorta?
Turner’s syndrome
A heart defect that causes a patient to appear cyanotic is what kind of shunt?
Right to left
What is the most common congenital cardiac anomaly?
Ventricular septal defect (VSD)
A 7 week old infant is noted to have a grade IV harsh, pansystolic murmur best heard at the left sternal border, with a diastolic rumble. What cardiac anomaly does this patient likely have?
VSD
- Additional Information: Soon after birth, CXR reveals increased pulmonary vasculature and left atrial enlargement.
What is the name of the cardiac anomaly which describes the persistence of fetal connection between the aorta and pulmonary trunk?
Patent ductus arteriosus (PDA)
Which vaccine preventable disease is associated with PDA?
Rubella
When examining a patient, you hear a machinery type systolic murmur. What cardiac anomaly does this fit with?
PDA
A 5 year female has a wide, fixed split S2 and grade III systolic ejection murmur on physical exam. What cardiac anomaly does this fit with?
Atrial Septal Defect (ASD)
What is the most common cyanotic cardiac lesion?
Tetralogy of Fallot
What are the four components of Tetralogy of Fallot?
1) Pulmonary stenosis
2) Right ventricular hypertrophy (RVH)
3) Aorta overrides membranous interventricular septum (aorta overriding VSD) 4) Interventricular septal defect (VSD)
What is the relationship of loudness to the severity of the pulmonary stenosis present with Tetralogy of Fallot?
Inversely related
What is the radiographic finding on CXR associated with Tetralogy of Fallot?
Boot-shaped heart
What is the most common cause of pericarditis?
Idiopathic
What is the most common identifiable cause of pericarditis?
Infection
A patient with pericarditis is able to relieve their chest pain through what two positions?
Sitting up and leaning forward.
What EKG finding is seen in pericarditis?
Diffuse ST Elevation
What is the most common cardiac manifestation of AIDS?
Pericardial Effusion
What is the most common cause of cardiac tamponade?
Trauma
What is Beck’s Triad of Cardiac Tamponade?
Hypotension, JVD, and muffled heart sounds
- Additional Information: Hypotension is resistant to fluid resuscitation. - Additional Information: JVD may be absent if hypovolemic
- Additional Information: The classic quartet adds on pulsus paradoxus.
What is the most common cause of endocarditis in non IV drug users?
Strep viridins
What valve is most commonly affected in endocarditis of non IV drug users?
Mitral valve
What are four important physical exam components to remember are associated with endocarditis?
Janeway lesions, Osler’s nodes, Roth spots, Splinter hemorrhages
- Additional Information: Infective endocarditis utilizes the Duke Criteria
What imaging study is used to diagnose endocarditis?
TEE (transesophageal echocardiogram)
What are the major criteria of Acute Rheumatic Fever?
JONES criteria
- Joints – polyarthritis
- O = <3 – carditis
- Nodules – subcutaneous nodules
- Erythema marginatum
- Sydenham chorea
Which valve is primarily affected in rheumatic heart disease?
Mitral valve
Which murmur radiates to the carotid arteries?
Aortic stenosis
What is the most common valvular disease in pregnancy?
Mitral stenosis
Are mitral or tricuspid stenosis systolic or diastolic murmurs?
Diastolic
Which lab test is more specific for myocardial infarction: myoglobin or troponin?
Troponin
What lab rises in congestive heart failure?
Brain Natriuretic Peptide (BNP)
What is the definitive diagnostic test for coronary artery disease?
Cardiac catheterization
A patient is determined to be bradycardic and hypotensive. What medication is given in an emergency situation to help increase AV conduction?
Atropine
- Additional Information: Atropine is an anticholinergic drug. It therefore inhibits action of acetylcholine at parasympathetic sites and increases cardiac output.
- Additional Information: If atropine is not effective, epinephrine or dopamine can be infused.
A patient is determined to be tachycardic and hypotensive. What is the next necessary step?
Synchronized cardioversion
What are the only two “shockable” rhythms?
Pulseless ventricular tachycardia and ventricular fibrillation.
A patient is tachycardic, hypotensive, and has a wide QRS. What medication is given in an effort to block the SA/AV nodes?
Amiodarone
- Additional Information: Amiodarone is a class III antiarrhythmic (K+ channel blockers)
- Additional Information: If the QRS is NOT wide, adenosine (causes transient heart block in AV node), beta blockers, or calcium channel blockers are used.
