Week 2 Cardiac

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What is the relationship between systolic pressure and stroke volume?

Lower systolic pressure has no effect on stroke volume

Higher systolic pressure leads to decreased stroke volume (correct)

Higher systolic pressure leads to increased stroke volume

Lower systolic pressure leads to decreased stroke volume

Which factor influences preload by contributing to ventricular wall tension at the end of diastole?

Atrial kick (correct)

Valvular regurgitation

Venous tone

Body position

What does the Frank-Starling mechanism state about the relationship between ventricular end-diastolic volume (preload) and stroke volume?

The heart will eject a greater stroke volume if it is filled to a smaller volume at the end of diastole

The heart's stroke volume is not affected by the end-diastolic volume

The heart will eject a greater stroke volume if it is filled to a greater volume at the end of diastole (correct)

The heart will have a lower stroke volume if it is filled to a smaller volume at the end of diastole

What is afterload in the context of ventricular function?

The force that the ventricle must overcome to eject its stroke volume Signup and view all the answers

How do increases in afterload affect the Frank-Starling curve and stroke volume?

Increases in afterload shift the curve down and to the right, decreasing stroke volume Signup and view all the answers

What is contractility defined as in the context of cardiac physiology?

The intrinsic strength of the heart muscle Signup and view all the answers

Which event takes place during diastole in the cardiac cycle?

Relaxation and passive filling of the ventricles with blood from atria Signup and view all the answers

What does Wigger's diagram depict?

Pressure waveform due to atrial systole, ventricular contraction, and pressure buildup from venous return before AV valve opens again Signup and view all the answers

Which type of hypertrophy is expected in response to mitral regurgitation?

Eccentric hypertrophy Signup and view all the answers

What is the normal mitral valve area?

$4-6$ cm2 Signup and view all the answers

Which condition is a cause of mitral stenosis?

Lupus Signup and view all the answers

What is the goal for heart rate in the anesthetic management of mitral stenosis?

Low normal Signup and view all the answers

What is the pathophysiological effect of chronic mitral regurgitation on the left ventricle?

Dilating and increasing end-diastolic volume Signup and view all the answers

Which condition is a cause of aortic regurgitation?

Rheumatic heart disease Signup and view all the answers

What is the expected effect of aortic regurgitation on the left ventricle?

Dilation and eccentric hypertrophy Signup and view all the answers

"Fast and forward" is a goal in the anesthetic management of which condition?

Mitral regurgitation Signup and view all the answers

What is the expected effect of aortic stenosis on ventricular thickness?

Thickening with decreased compliance Signup and view all the answers

What does the acronym 'SAD' represent in the context of aortic stenosis?

Syncope, angina, dyspnea Signup and view all the answers

What is the primary role of Bachmann's bundle in the heart's conduction system?

Preferential path for electrical activation of the left atrium Signup and view all the answers

What is the role of Purkinje fibers in the heart's conduction system?

Rapidly conduct the action potential to myocytes throughout the ventricles Signup and view all the answers

What is the main function of the SA node in the heart's conduction system?

Generates the action potential leading to depolarization of all other cardiac muscle cells Signup and view all the answers

Which part of the heart serves as the link between atrial and ventricular depolarization?

AV node Signup and view all the answers

What occurs as a result of dysfunction in the left bundle branch of the heart's conduction system?

Excess widths of QRS > 0.12 Signup and view all the answers

Which part of the heart plays a role in atrial fibrillation and interatrial block?

Bachmann's bundle Signup and view all the answers

What is the major function of the bundle of His (AV bundle) in the heart's conduction system?

Conducts action potential to right and left bundle branches Signup and view all the answers

What is the significance of gap junctions in the heart's conduction system?

Allows spread of action potentials between myocardial cells Signup and view all the answers

What occurs during systole in the cardiac cycle?

Contraction and tension development Signup and view all the answers

What is the primary function of isovolumetric relaxation in the cardiac cycle?

Relaxation of the ventricular myocardium Signup and view all the answers

What does the pressure-volume loop provide an assessment of?

Integrity of cardiac valves Signup and view all the answers

What happens when LV pressure exceeds LA pressure but is less than aortic pressure in the cardiac cycle?

Mitral valve closes Signup and view all the answers

Which phase of the cardiac cycle is characterized by a period of rapid ejection of blood from the ventricle?

Ejection Signup and view all the answers

What happens when LV pressure falls below aortic pressure in the cardiac cycle?

Aortic valve closes Signup and view all the answers

What is the primary factor responsible for LV dysfunction when EF < 40%?

Low ejection fraction (EF) Signup and view all the answers

What is the primary indicator used to calculate stroke volume in the pressure-volume loop?

$EDV - ESV$ Signup and view all the answers

What is the primary determinant of resting membrane potential (RMP) in cells?

Potassium Signup and view all the answers

What happens to the RMP when serum potassium (K+) decreases?

RMP becomes more negative Signup and view all the answers

What initiates the depolarization of the cell membrane?

Voltage-gated sodium channel opening Signup and view all the answers

What is the main function of the Sodium-Potassium ATPase (pump) in cardiac cells?

Restores ionic balance towards RMP Signup and view all the answers

What is the characteristic feature of the SA node's resting membrane potential (RMP)?

-55 to -60 mV RMP Signup and view all the answers

What is responsible for the slow depolarization known as 'pacemaker potential' in the SA node?

Sodium influx Signup and view all the answers

What is the rate of inherent conduction for atrial pacemakers (SA node)?

60-100 bpm Signup and view all the answers

What are the typical rates of conduction for Purkinje fibers?

<20 bpm Signup and view all the answers

What is the hallmark of right bundle branch block (RBBB) on an ECG?

Widened and upwardly deflected QRS complex in lead V1 Signup and view all the answers

Which phase of the ventricular muscle action potential is characterized by the opening of voltage-gated L-type Ca++ channels?

Phase 2 Signup and view all the answers

What is the resting membrane potential (RMP) of the ventricular muscle cell?

-90 mV Signup and view all the answers

During which phase of the action potential is the cell easier to depolarize?

Threshold potential Signup and view all the answers

What is the absolute refractory period in the context of action potentials?

Time during which an action potential may not be evoked, even if elicited by a stimulus Signup and view all the answers

What ion is the myocyte permeable to, but not to other electrolytes or proteins?

Potassium (K+) Signup and view all the answers

What differentiates the action potentials of different types of heart cells?

Shape of the action potential Signup and view all the answers

What phenomenon refers to the internal voltage at which the cell depolarizes and exhibits an all or none response?