NUR 376
Week 4 Module 3B
Cardiac Part 2 of 2 Outline
Applied Pathophysiology - Concordia St. Paul
Pass the Exam with Confidence
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NUR 376 Applied
Pathophysiology Week 4 Module 3B
Cardiac Part 2 of 2 Outline
by Rhaeven Ortiz
This week you will be learning about valve disorders and heart failure (HF). There are hints through this outline for
your heart failure assignment.
• Learning Objectives:
o Identify risk factors and preventative measures for left and right heart failure.
o Differentiate the pathophysiologic mechanisms of left and right heart failure.
o Compare/contrast and provide rationales for the clinical manifestations of left and right sided heart
failure.
o Explain pulmonary dysfunction in heart failure.
o Differentiate between two major types of valvular dysfunction.
o Explain the pathophysiology of valvular dysfunction including the consequences.
• Ch. 17
o Review pages 400-408
▪ Left ventricular ejection fraction - percentage of blood propelled out of the left ventricle with each
contraction.
▪ Box 17-1 (in pharm you will learn why we give certain meds)
▪ Cardiac Output = HR x SV
HR = number of ventricular contractions per minute; avg is 70 bpm
SV = mLs of blood ejected per ventricular contraction; in health individual it is
~70 mL Amount of blood that the heart pumps out of the left ventricle each
minute
▪ Preload - volume of blood at the end of diastole or the volume of blood that enters the right
atrium from the venous system
▪ Afterload - amount of resistance that the ventricle must overcome in order to pump blood out
of the heart; workload of the left ventricle, or resistance exerted by the pressure within the aorta
against the left ventricle. The greater the systemic arterial vascular resistance, the greater the
afterload against the left ventricle.
▪ Cardiac Contractility
• Inotropic vs chronotropic
Inotropic Versus Chronotropic Function of the Heart. The inotropic function of the heart refers
1
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to the force of contraction of the cardiac muscle. The heart’s contractility can be influenced
by the amount of calcium available for interaction between the actin and myosin filaments of
the cardiac muscle fibers. Sympathetic stimulation can increase force of contraction, which is
referred to as a positive inotropic effect.
Chronotropic function refers to heart rate (HR). When digitalis is administered, it decreases HR
by slowing conduction of impulses through the atrioventricular (AV) node; therefore, it has a
negative chronotropic effect. Beta-adrenergic blocking agents antagonize the SNS effect on
the heart by slowing impulses at the sinoatrial (SA) node, also a negative chronotropic effect.
Conversely, epinephrine, an adrenergic or sympathetic stimulant, has positive inotropic and
positive chronotropic effects on the heart. Under the influence of epinephrine, the heart has
a greater force of contraction and increased heart rate.
2
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▪ Frank-Starling Law (box 17-3)
3
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Week 4 Module 3B
Cardiac Part 2 of 2 Outline
Applied Pathophysiology - Concordia St. Paul
Pass the Exam with Confidence
, lOMoARcPSD|51648332
NUR 376 Applied
Pathophysiology Week 4 Module 3B
Cardiac Part 2 of 2 Outline
by Rhaeven Ortiz
This week you will be learning about valve disorders and heart failure (HF). There are hints through this outline for
your heart failure assignment.
• Learning Objectives:
o Identify risk factors and preventative measures for left and right heart failure.
o Differentiate the pathophysiologic mechanisms of left and right heart failure.
o Compare/contrast and provide rationales for the clinical manifestations of left and right sided heart
failure.
o Explain pulmonary dysfunction in heart failure.
o Differentiate between two major types of valvular dysfunction.
o Explain the pathophysiology of valvular dysfunction including the consequences.
• Ch. 17
o Review pages 400-408
▪ Left ventricular ejection fraction - percentage of blood propelled out of the left ventricle with each
contraction.
▪ Box 17-1 (in pharm you will learn why we give certain meds)
▪ Cardiac Output = HR x SV
HR = number of ventricular contractions per minute; avg is 70 bpm
SV = mLs of blood ejected per ventricular contraction; in health individual it is
~70 mL Amount of blood that the heart pumps out of the left ventricle each
minute
▪ Preload - volume of blood at the end of diastole or the volume of blood that enters the right
atrium from the venous system
▪ Afterload - amount of resistance that the ventricle must overcome in order to pump blood out
of the heart; workload of the left ventricle, or resistance exerted by the pressure within the aorta
against the left ventricle. The greater the systemic arterial vascular resistance, the greater the
afterload against the left ventricle.
▪ Cardiac Contractility
• Inotropic vs chronotropic
Inotropic Versus Chronotropic Function of the Heart. The inotropic function of the heart refers
1
Downloaded by Benjamin Luca ()
, lOMoARcPSD|51648332
to the force of contraction of the cardiac muscle. The heart’s contractility can be influenced
by the amount of calcium available for interaction between the actin and myosin filaments of
the cardiac muscle fibers. Sympathetic stimulation can increase force of contraction, which is
referred to as a positive inotropic effect.
Chronotropic function refers to heart rate (HR). When digitalis is administered, it decreases HR
by slowing conduction of impulses through the atrioventricular (AV) node; therefore, it has a
negative chronotropic effect. Beta-adrenergic blocking agents antagonize the SNS effect on
the heart by slowing impulses at the sinoatrial (SA) node, also a negative chronotropic effect.
Conversely, epinephrine, an adrenergic or sympathetic stimulant, has positive inotropic and
positive chronotropic effects on the heart. Under the influence of epinephrine, the heart has
a greater force of contraction and increased heart rate.
2
Downloaded by Benjamin Luca ()
, lOMoARcPSD|51648332
▪ Frank-Starling Law (box 17-3)
3
Downloaded by Benjamin Luca ()
