CHAPTER 12 | Cardiac Anatomy and Physiology Flashcards
__ is the parasympathetic-mediated reflex occurs when stretch receptors located mainly in the left ventricle respond to an acute decrease in left ventricular preload
A. Bezold-Jarisch reflex
B. Baroreceptor reflex
C. Bainbridge reflex
D. Carotid sinus reflex
A. Bezold-Jarisch reflex
parasympathetic-mediated reflex occurs when stretch receptors located mainly in the left ventricle respond to an acute decrease in left ventricular preload. The result is bradycardia and reduced contractility (and resultant hypotension)
- this is thought to occur to give ventricle MORE TIME to fill an increase preload.
The “dominance” of the coronary circulation is determined on the basis of which major coronary artery feeds the
_______
A. Left anterior descending coronary artery
B. Left circumflex artery
C. Posterior descending coronary artery
D. Right coronary artery
C. Posterior descending coronary artery
In 55% of patients, the sinoatrial (SA) node
is perfused by the ________
A. Left anterior descending coronary artery
B. Left circumflex artery
C. Posterior descending coronary artery
D. Right coronary artery
D. Right coronary artery
Blood supply to the LV is inversely related to the vascular resistance to flow, which varies to the fourth power of the radius of the vessel:
A. Laplace’s Law
B. Bernoulli’s principle
C. Frank-Starling effect
D. Poiseuille’s Law
D. Poiseuille’s Law
What is the primary determinant of myocardial O2 demand?
A. Heart rate
B. Contractility
C. Afterload
D. Preload
A. Heart rate
Which of the following is most accurate in terms of the hemodynamic goal in Coronary artery disease(CAD)
A. Decrease in preload
B. Maintain tachycardia
C. Increase in preload
D. Increase in afterload
A. Decrease in preload
In the current guideline of ACLS, when a patient is suspected to have a β-blocker or calcium channel blocker overdose, the epinephrine dose can be increased to:
A. 3 - 7 mg
B. 2 - 3 mg
C. 3 - 4 mg
A. 3 - 7 mg
Current recommendations are to give 1 mg of epinephrine IV every 3 to 5 minutes in the adult. The easiest way to manage this is to administer 1 mg of epinephrine approximately every other 2-minute cycle of CPR (i.e., about
every 4 minutes).
If this dose seems ineffective or in the setting of β-blocker
or calcium channel blocker overdose, higher doses (3 to 7 mg) may be considered.
The innervation of AV node is primarily from:
A. Right vagus nerve
B. Left vagus nerve
C. Cardio-accelerator fibers (T1-T4)
B. Left vagus nerve
Dictum:
SA node: Right vagus
AV node: Left vagus
Is the external resistance to chamber emptying after contraction begins and the aortic valve opens:
A. PRELOAD
B. AFTERLOAD
C. MYOCARDIAL RESISTANCE
B. AFTERLOAD
This is the amount of blood that a chamber contains immediately before contraction BEGINS:
A. PRELOAD
B. AFTERLOAD
C. MYOCARDIAL RESISTANCE
A. PRELOAD
Is the force of contraction under controlled heart rate and loading conditions:
A. PRELOAD
B. AFTERLOAD
C. MYOCARDIAL CONTRACTILITY
Myocardial contractility
This refers to the mechanism whereby alterations in muscle tension and length that occur during contraction and relaxation in the sarcomere are translated into phasic changes in pressure and volume that occur in the intact heart:
A. Laplace Law
B. Poiseuille’s Law
C. Frank-Starling Mechanism
A. Laplace Law
Analogously, the elevated LV pressure in severe aortic valve stenosis produces greater systolic LV wall stress. These increases in LV wall stress cause parallel increases in
myocardial oxygen demand because the myofilaments require more energy to develop enhanced tension.
Conversely, Laplace’s law indicates that an increase in wall thickness will reduce wall stress and tension developed by individual sarcomeres.
Major phases of left ventricular systole EXCEPT:
A. Isovolumic contraction
B. Atrial systole
C. Rapid ejection
D. Slower ejection
B. Atrial systole
The first phase of LV systole is isovolumic contraction, which describes the time interval between mitral valve closure
and aortic valve opening during which LV volume remains constant.
Major phases of LV diastole EXCEPT:
A. isovolumic relaxation
B. early ventricular filling
C. slower ejection
D. atrial systole
C. slower ejection
LV diastole is divided into four phases: isovolumic relaxation, early ventricular filling, diastasis, and atrial systole.
“c” wave of the left atrium pressure
waveform represents _______
A. Left atrial contraction
B. Left atrial filling during left ventricular early relaxation
C. Mitral valve closure during left ventricular systole
D. Diastasis
C. Mitral valve closure during left ventricular systole
“x descent of the left atrium pressure waveform corresponds to which cardiac mechanical event:
A. Atrial contraction
B. Atrial relaxation
C. Early ventricular filling
B. Atrial relaxation
Formula for ejection fraction:
A. Stroke volume / end-diastolic volume
B. Stroke volume / end-systolic volume
C. End-systolic volume / end-diastolic volume
D. End-systolic volume / stroke volume
A. Stroke volume / end-diastolic volume
At what point of the left ventricular pressure-volume diagram does the aortic valve open?
A. A
B. B
C. C
D. D
point B
A - Mital valve closes
B - Aortic valve opens
C - Aortic valve closes
D - Mitral Valve opens
At what point of the left ventricular pressure-volume diagram does ISOVOLUMIC RELAXATION occurs?
A. C-D
B. B-C
C. D-A
D. A-B
A. C-D
Wall tension is directly proportional to intracavitary pressure and radius and inversely proportional to wall thickness:
A. Laplace’s Law
B. Bernoulli’s principle
C. Frank-Starling effect
D. Poiseuille’s Law
A. Laplace’s Law
The area most vulnerable to ischemia
is the ________
A. Subendocardium of right ventricle
B. Subendocardium of left ventricle
C. Myocardium of right ventricle
D. Myocardium of left ventricle
B. Subendocardium of left ventricle
Calcium channel blocker with the greatest
negative inotropic effect:
A. Nicardipine
B. Diltiazem
C. Nifedipine
D. Verapamil
D. Verapamil
Which valvular heart disease presentschallenges during cardioplegia?
A. Mitral stenosis
B. Tricuspid insufficiency
C. Aortic stenosis
D. Aortic insufficiency
D. Aortic insufficiency
The risk for rupture increases abruptly as
thoracic aneurysms reach a diameter of
_______
A. 4 cm
B. 5 cm
C. 6 cm
D. 7 cm
C. 6 cm
Neutralization ratio of heparin and
protamine
A. 1 mg of protamine to 1 U of heparin
B. 1 mg of protamine to 10 U of heparin
C. 1 mg of protamine to 100 U of heparin
D. 1 mg of protamine to 1000 U of heparin
C. 1 mg of protamine to 100 U of heparin
What is the most devastating complication associated with protamine?
A. Pulmonary embolism
B. Anaphylaxis
C. Left ventricular failure
D. Pulmonary hypertension
D. Pulmonary hypertension
Which of the following drugs DECREASES/SHORTENS the ERP(effective refractory period) of the cardiac action potential?
A. Lidocaine
B. Flecainide
C. Amiodarone
D. Quinidine
A. Lidocaine
CLASS 1A - Lengthens the ERP
CLASS1B - Shortens the ERP
CLASS 1C - No effect on ERP
Because CLASS 1A drugs bind to and detach from the sodium channel rapidly and have greater affinity for the active and inactivated (but not resting) state, they are typically useful in tachyarrhythmias.
Most coronary blood flow to the “LV” occur during which part of the cardiac cycle?
A. Systole
B. Diastole
B. Diastole
What determines the dominance of the coronary circulation?
A. posterior descending coronary a.
B. left circumflex a.
C. LAD
A. posterior descending coronary a.
What are the major sources of blood supply to the LA?
A. LCCA
B. LAD
C. RCA
A. LCCA
What is the total volume of pericardial interstitial fluid:
A. 15 - 35ml
B. 5 - 10ml
C. 40 - 45ml
A. 15 - 35ml
___ Is the duration of aortic valve closure to mitral valve opening. A commonly used noninvasive index of LV relaxation that is usually measured using M-mode:
A. Isovolumic relaxation time
B. Isovolumic contraction time
A. Isovolumic relaxation time
What valvular disease is represented by this pressure-volume loop abnormality?
A. Mitral Stenosis
B. Mitral Regurgitation
C. Aortic Stenosis
D. Aortic Insufficiency
B. Mitral Regurgitation
Small - Acute MR
Big - Chronic MR
Which point in the graph provided corresponds to isovolumetric contraction?
A. A-B
B. B-C
C. C-D
D. D-A
B - C
This cardiac pressure volume loop change is:
A. AS (Aortic Stenosis)
B. MR (Mitral Regurgitation)
C. AI (Aortic Insufficiency)
D. MS (Mitral Stenosis)
A. AS (Aortic Stenosis)
- Increased peak systolic pressure (tall curve)
- Increased ventricular afterload
- Decreased stroke volume (decreased loop width)
- Increased end-systolic volume (left part of curve right shifted)
- Increased end-diastolic volume (right part of curve right shifted
What valvular disease is depicted in this pressure-volume loop diagram?
A. Mitral Stenosis
B. Mitral Regurgitation
C. Aortic Stenosis
D. Aortic Insufficiency
A. Mitral Stenosis
- Decreased end-diastolic volume (preload) (right part of curve left shifted)
- Decreased stroke volume (decreased loop width)
- Decreased end-systolic volume (left part of curve left shifted)
What disease state is represented by this pressure-volume loop abnormality?
A. Mitral Stenosis
B. Hypertrophic Cardiomyopathy
C. Cardiac Tamponade
D. Aortic Stenosis
C. Cardiac Tamponade
decreased LVEDV shifts loop to left
decreased stroke volume narrows the loop
decreased ventricular compliance (notice slope during ventricular filling)
1 MET is equivalent to a consumption of:
A. 3.5 mL O2/kg/min
B. 3.0 mL O2/kg/min
C. 2.5 mL O2/kg/min
A. 3.5 mL O2/kg/min
This is the most common clinical estimate of LV afterload:
A. SVR
B. MAP
C. PVR
D. C.I. (Cardiac Index)
Systemic vascular resistance
(MAP - R arterial pressure)
Defined as the ratio of continuous aortic pressure to blood flow:
A. Input impedance
B. Isovolumic relaxation time
C. Isovolumic contraction time
A. Input impedance
This is responsible for the transmission of the SA node depolarization from the RA to the LA across the atrial septum:
A. Bachmann’s bundle
B. Primary chordae tendinae
C. Tertiary chordae tindinae
A. Bachmann’s bundle
What disease state is represented by this pressure-volume loop abnormality?
A. Mitral Stenosis
B. Aortic Regurgitation
C. Cardiac Tamponade
D. Aortic Stenosis
B. Aortic Regurgitation
- No true phase of isovolumetric relaxation because as the ventricle relaxes, blood is entering the ventricle from the aorta thereby increasing ventricular volume (round, fat curve)
- Increased end-diastolic volume (right part of curve right shifted)
- No true isovolumetric contraction because volume continues to increase
*Increased stroke volume (large loop width)
- Increased end-systolic volume (left part of curve right shifted)
What is the normal stroke volume?
A. 90 mL
B. 100 mL
C. 120 mL
A. 60 - 90 mL
Formula: EDV - ESV
What is the normal Cardiac Index?
A. 2.5 - 4.0 L/min/m2
B. 1.5 -3.0 L/min/m2
A. 2.5 - 4.0 L/min/m2
What is the normal stroke index?
A. 40 - 60 mL/beat/m2
B. 30 - 50 mL/beat/m2
A. 40 - 60 mL/beat/m2
What is the normal PVR?
A. 100 - 300 dynes-cm-sec
B. 50 - 150 dynes-cm-sec
A. 100 - 300 dynes-cm-sec
The S2 is normally split because what valve closes slightly after?
A. Pulmonic Valve
B. Mitral Valve
C. Aortic Valve
A. Pulmonic Valve
This refers to the autoregulation method by which myocardial tension increases with an increase in heart rate:
A. Treppe effect
B. Anrep effect
C. Woodworth (staircase) phenomenon
Treppe or Bowditch effect
Is an autoregulation method in which myocardial contractility increases with afterload:
A. Treppe effect
B. Anrep effect
C. Woodworth (staircase) phenomenon
Anrep effect
This phenomenon is exhibited by skeletal and heart muscle when subjected to rapidly repeated maximal stimuli following a period of rest thereby resulting to a series of contractions, each is greater than the preceding one until a state of maximum contraction is reached:
A. Treppe effect
B. Anrep effect
C. Woodworth (staircase) phenomenon
C. Woodworth (staircase) phenomenon
Which valve does not have a collagenous annulus?
A. Tricuspid valve
B. Aortic Valve
C. Mitral Valve
D. Pulmonic Valve
A. Tricuspid valve
What class of anti-arrhythmic drugs blocks phase 0 (slows) - Na+ and phase 3 (prolongs) - K+?
A. Class IA
B. Class IC
C. Class III
A. Class IA
Quinidine
Procainamide
Disopyramide
MOA: Block phase 0 (slows) - Na+ and Block phase 3 (prolongs) - K+
SIDE EFFECTS: Hardly ever used because of side effects, proarrhythmic (Induce prolonged QT), high cardiac and non-cardiac risk.
