Cardio - Physiology (Part 1) Flashcards Preview

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Flashcards in Cardio - Physiology (Part 1) Deck (147)
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1
Q

In what areas are the murmurs of aortic stenosis and aortic regurgitation best heard?

A

(A) aortic area (i.e., right sternal border and second intercostal space) and (E) left sternal border, respectively

2
Q

In what areas are the murmurs of pulmonic stenosis and pulmonic regurgitation best heard?

A

(B) pulmonic area (i.e., left sternal border at second intercostal space) and (E) left sternal border, respectively

3
Q

On which part of the chest are tricuspid valve murmurs best auscultated?

A

(C) tricuspid area (i.e., the left sternal border at the fifth intercostal space)

4
Q

In what area is the murmur of a ventricular septal defect best heard?

A

(C) tricuspid area (i.e., left sternal border at fifth intercostal space)

5
Q

In what area is the murmur of an atrial septal defect best heard?

A

(C) tricuspid area

6
Q

In what areas are flow murmurs best heard?

A

(A) aortic area and

(B) pulmonic area

7
Q

In what area is the murmur of hypertrophic cardiomyopathy best heard?

A

(E) left sternal border

8
Q

What are the two equations for mean arterial pressure?

A

Mean atrial pressure = cardiac output x total peripheral resistance; mean atrial pressure = (1/3) systolic pressure + (2/3) diastolic pressure

9
Q

Pulse pressure is proportional to what other cardiac parameter?

A

Stroke volume

10
Q

What accounts for the increase in cardiac output in the first stages of exercise?

A

An increase in stroke volume is responsible for the increase in cardiac output in the first stages of exercise

11
Q

What accounts for the increase in cardiac output after prolonged exercise?

A

An increase in heart rate is responsible for the increase in cardiac output after prolonged exercise

12
Q

What accounts for the decrease in cardiac output at very high heart rates?

A

At very high heart rates, the ventricles are unable to fill completely during diastole; therefore, the cardiac output decreases

13
Q

Cardiac output = stroke volume x _____ _____.

A

Heart rate

14
Q

What is Ficks principle?

A

Cardiac output = rate of oxygen consumption / (arterial oxygen content - venous oxygen content)

15
Q

Stroke volume = end-diastolic volume - _____ _____.

A

End-systolic volume

16
Q

With an increase in stroke volume, one would expect the heart to have a(n) _____ (decrease/increase) in preload, a(n) _____ (decrease/increase) in afterload, and/or a(n) _____ (decrease/increase) in contractility.

A

Increase; decrease; increase

17
Q

What are the three variables that affect stroke volume?

A

Contractility, Afterload, and Preload (remember the mnemonic SV CAP)

18
Q

How does digitalis affect contractility (and thus stroke volume)?

A

Digitalis increases contractility by causing an increase in intracellular sodium, which results in an increase in intracellular calcium, which strengthens contractions

19
Q

How does hypoxia affect contractility?

A

Hypoxia causes a decrease in contractility and in stroke volume

20
Q

How do calcium channel blockers affect contractility and stroke volume?

A

Calcium channel blockers decrease contractility and stroke volume by decreasing intracellular calcium

21
Q

How does increasing intracellular calcium affect contractility (and thus stroke volume)?

A

An increase in intracellular calcium increases contractility; this is the mechanism of digitalis

22
Q

How does decreasing extracellular sodium affect contractility (and thus stroke volume)?

A

A decrease in extracellular sodium increases contractility by decreasing the activity of the sodium/calcium ion exchanger

23
Q

How does acidosis affect contractility?

A

Acidosis decreases contractility

24
Q

Would a patient with hypertrophic cardiomyopathy have an increase or decrease in myocardial oxygen demand?

A

Increase

25
Q

How does 1 blockade affect contractility and stroke volume?

A

1 blockade decreases contractility and stroke volume

26
Q

Would chronic hypertension increase or decrease myocardial oxygen demand? By what mechanism?

A

Chronic hypertension would cause an increase in myocardial oxygen demand by causing an increase in afterload

27
Q

How do catecholamines affect contractility (and thus stroke volume)?

A

Catecholamines increase contractility

28
Q

By what mechanism do catecholamines cause an increase in contractility?

A

By increasing the activity of the calcium pump in the sarcoplasmic reticulum

29
Q

Does pregnancy increase or decrease stroke volume?

A

Increase

30
Q

By what mechanism does increasing heart size increase myocardial oxygen demand?

A

By causing an increase in wall tension

31
Q

Does increasing contractility increase or decrease myocardial oxygen demand?

A

Increase

32
Q

________ (Preload/Afterload) = ventricular end-diastolic volume.

A

Preload

33
Q

_____ (Preload/Afterload) = mean arterial pressure.

A

Afterload

34
Q

Would you expect nitroglycerin to decrease preload or afterload? By what mechanism?

A

Nitroglycerin decreases preload by causing venodilation

35
Q

Would you expect hydralazine to decrease preload or afterload? By what mechanism?

A

Hydralazine decreases afterload by causing arterial dilation

36
Q

A 60-year-old male patient mistakenly receives triple the maintenance level of intravenous fluids for 24 hours. Do you expect his preload to increase or decrease?

A

Increase

37
Q

An increase in peripheral resistance will cause an _____ (increase/decrease) in afterload.

A

Increase

38
Q

The Starling curve represents the relationship between which two cardiac parameters?

A

Preload and cardiac output

39
Q

The Starling curve shows that the force of contraction is proportional to what?

A

The preload or the initial length of the cardiac muscle fiber

40
Q

Do -blockers and calcium channel blockers increase or decrease contractile strength?

A

Decrease

41
Q

Does sympathetic stimulation increase or decrease contractility of the heart?

A

Increase

42
Q

Do circulating catecholamines increase or decrease contractility of the heart?

A

Increase

43
Q

Does digitalis increase or decrease contractile strength?

A

Increase

44
Q

What is the equation for ejection fraction?

A

Ejection fraction = (end-diastolic volume - end-systolic volume) ÷ end-diastolic volume

45
Q

The cardiac ejection fraction is normally greater than what percentage of the total end-diastolic volume?

A

55%

46
Q

Would an increase in end-diastolic volume be indicative of an increase or decrease in the ejection fraction?

A

Decrease

47
Q

Ejection fraction is used as an indication of which cardiac parameter?

A

Contractility

48
Q

Ejection fraction = _____ _____ / end-diastolic volume.

A

Stroke volume

49
Q

Name three hematologic disease states in which the viscosity of blood increases.

A

Polycythemia, multiple myeloma (or other hyperproteinemic states), hereditary spherocytosis

50
Q

What is Ohms law?

A

Change in voltage (V1 - V2) = current (I) x resistance (R)

51
Q

In cardiology, by what factor does resistance increase in a vessel whose size is reduced by one half?

A

16 times; resistance is inversely proportional to the radius to the fourth power

52
Q

Which equation in cardiology, relating the variables of resistance, pressure, and flow, is a restatement of Ohms law?

A

Change in pressure (P1 - P2) = flow (Q) x resistance (R)

53
Q

Which blood vessels account for most of total peripheral resistance?

A

Arterioles

54
Q

What is the equation for blood vessel resistance that incorporates variables of viscosity, length, and radius?

A

Resistance = (8 x viscosity x length) / ( x [r4])

55
Q

Pressure gradient drives flow from _____ (high/low) pressure to _____ (high/low) pressure.

A

High; low

56
Q

What is the equation for the total resistance of blood vessels in series?

A

Total resistance = R1 + R2 + R3…

57
Q

What is the equation for the total resistance of blood vessels in parallel?

A

1/(Total resistance) = 1 / R1 + 1 / R2 + 1 / R3…

58
Q

Which parameter does the viscosity of blood mostly depend on?

A

Hematocrit

59
Q

An increase in blood volume leads to a(n) _____ (increase/decrease) in right atrial pressure and a(n) _____ (increase/decrease) in cardiac output.

A

Increase; increase

60
Q

What is the name for the point at which cardiac output is equal to venous return?

A

The operating point of the heart

61
Q

A 23-year-old man has significant blood loss following a motor vehicle accident. A decrease in blood volume leads to a(n) _____ (increase/decrease) in right atrial pressure and a(n) _____ (increase/decrease) in cardiac output.

A

Decrease; decrease

62
Q

What does the x-intercept of the venous return curve signify?

A

The value of the mean systemic pressure

63
Q

A 76-year-old man with congestive heart failure is given digoxin as a positive inotrope. An increase in inotropy leads to a(n) _____ (increase/decrease) in cardiac output and a(n) _____ (increase/decrease) in right atrial pressure.

A

Increase; increase

64
Q

A 10-year-old boy presents with dehydration following acute diarrhea. He receives 2 liters of normal saline. An increase in blood volume leads to a(n) _____ (increase/decrease) in right atrial pressure and a(n) _____ (increase/decrease) in cardiac output.

A

Increase; increase

65
Q

What causes the S4 heart sound or atrial kick?

A

The left atrium pushing against a stiff left ventricular wall in a patient with ventricular hypertrophy

66
Q

What phase of the cardiac cycle corresponds with the period between the opening and closing of the aortic valve?

A

Systolic ejection

67
Q

In relation to the cardiac cycle, the A wave of the jugular venous pulse is associated with what?

A

Contraction of the atrium

68
Q

What phase of the cardiac cycle corresponds with the period between mitral valve closure and aortic valve opening?

A

Isovolumetric contraction

69
Q

What is the name of the finding on auscultation that occurs when the aortic valve closes before the pulmonic valve?

A

S2 splitting

70
Q

What phase of the cardiac cycle corresponds with the period just after mitral valve opening?

A

Rapid filling

71
Q

On auscultation of a patient with an atrial septal defect during inspiration, does the time period between pulmonic and aortic valvular closure increase, decrease, or stay the same?

A

Stays the same; because pressures can equalize across the atrial wall, there is no change in splitting during inspiration

72
Q

What phase of the cardiac cycle corresponds with the period just before mitral valve closure?

A

Reduced filling

73
Q

What phase of the cardiac cycle corresponds with the period of highest oxygen consumption?

A

Isovolumetric contraction

74
Q

What phase of the cardiac cycle corresponds with the period between the closing of the aortic valve and the opening of the mitral valve?

A

Isovolumetric relaxation

75
Q

Which heart sound is also referred to as the atrial kick?

A

S4

76
Q

With regard to auscultation of the heart, in what area is S1 loudest?

A

The mitral area (ie, the midclavicular line in the fifth intercostal space)

77
Q

Which heart sound occurs during aortic and pulmonary valve closure?

A

S2

78
Q

With regard to auscultation of the heart, in what area is S2 loudest?

A

The left sternal border

79
Q

True or false: The presence of an S3 in children always indicates a cardiac defect.

A

False; S3 can be a normal finding in children and pregnant women

80
Q

Which abnormal heart sound is associated with dilated congestive heart failure?

A

S3

81
Q

Which abnormal heart sound is associated with a hypertrophic ventricle?

A

S4

82
Q

Which abnormal heart sound occurs during rapid ventricular filling?

A

S3

83
Q

Which heart sound occurs during mitral and tricuspid valve closure?

A

S1

84
Q

In relation to the cardiac cycle, the C wave of the jugular venous pulse is associated with what contraction?

A

Right ventricle contraction (ie, the tricuspid valve bulging into the atrium)

85
Q

In relation to the cardiac cycle, the V wave of the jugular venous pulse is associated with what?

A

Increased atrial pressure as a result of filling against the closed tricuspid valve

86
Q

During a physical examination, what diagnostic sign may be observable in the neck of a patient with right heart failure?

A

Elevated jugular venous pressure

87
Q

When listening to a normal heart, which valve closes first during S2: the aortic valve or the pulmonic valve?

A

The aortic valve

88
Q

How is normal S2 splitting increased?

A

By inspiration

89
Q

In which disorder is the paradoxical splitting of the S2 heart sound seen?

A

Aortic stenosis

90
Q

Wide splitting of the S2 heart sound is associated with _____ stenosis.

A

Pulmonic

91
Q

What is the name of the phenomenon that occurs when P2 (pulmonic valve) precedes A2 (aortic valve) in the heart sound S2?

A

Paradoxic splitting

92
Q

During auscultation of a patient with aortic stenosis during inspiration, does the time period between pulmonic and aortic valvular closure increase or decrease?

A

Decrease; this is known as paradoxical splitting

93
Q

During which phase is ventricular volume highest?

A

During atrial systole

94
Q

During which phase is ventricular volume lowest?

A

During isovolumetric relaxation

95
Q

_____ (Normal/Wide/Fixed/Paradoxical) splitting is seen in conditions that delay left ventricular emptying (ie, aortic stenosis and left bundle-branch block).

A

Paradoxical

96
Q

Normal inspiration causes a _____ (increase/decrease) in intrathoracic pressure, which in turn causes _____ (increased/decreased) capacity for pulmonary blood flow.

A

Decrease; increased

97
Q

_____ (Normal/Wide/Fixed/Paradoxical) splitting is seen in conditions that delay right ventricle emptying (ie, pulmonic stenosis and right bundle-branch block).

A

Wide

98
Q

In normal splitting of the S2 heart sound, the pulmonic valve closes later during inspiration due to _____ (increased/decreased) blood flow in lungs, and the aortic valve closes earlier during inspiration due to _____ (increased/decreased) venous return to the left heart.

A

Increased; decreased

99
Q

Regarding auscultation of the heart, in what areas are the murmurs of aortic stenosis and aortic regurgitation best heard?

A

The aortic area (ie, the right sternal border and the second intercostal space) and the left sternal border, respectively

100
Q

In which phase of the cardiac cycle is the murmur of aortic stenosis heard?

A

Systole

101
Q

Regarding auscultation of the heart, in what areas are the murmurs of pulmonic stenosis and pulmonic regurgitation best heard?

A

The pulmonic area (ie, the left sternal border at the second intercostal space) and the left sternal border, respectively

102
Q

On which part of the chest are tricuspid valve murmurs best auscultated?

A

The tricuspid area (ie, the left sternal border at the fifth intercostal space)

103
Q

Regarding auscultation of the heart, in what area is the murmur of a ventricular septal defect best heard?

A

The tricuspid area (ie, the left sternal border at the fifth intercostal space)

104
Q

In which phase of the cardiac cycle is the murmur of tricuspid stenosis heard?

A

Diastole

105
Q

On which part of the chest are mitral valve murmurs best auscultated?

A

The mitral area (ie, the midclavicular line at the fifth intercostal space)

106
Q

In which phases of the cardiac cycle are the murmurs of mitral stenosis and mitral regurgitation heard?

A

Diastole and systole, respectively

107
Q

In which phase of the cardiac cycle are the murmurs of aortic regurgitation and pulmonic regurgitation heard?

A

Diastole

108
Q

With regard to auscultation of the heart, in what area is the murmur of an atrial septal defect best heard?

A

The tricuspid area (ie, the left sternal border at the fifth intercostal space)

109
Q

Pulmonic flow murmurs and diastolic rumbles are commonly associated with which cardiac defect?

A

Atrial septal defects. The pulmonic flow murmur is due to increased flow through the pulmonary valve, and the diastolic rumble is due to increased flow across the tricuspid valve

110
Q

With regard to auscultation of the heart, in what area are flow murmurs best heard?

A

The second intercostal space and both the left and right sternal borders

111
Q

A murmur of hypertrophic cardiomyopathy occurs in the ______ phase of the cardiac cycle.

A

Systolic

112
Q

With regard to auscultation of the heart, in what area is the murmur of hypertrophic cardiomyopathy best heard?

A

The left sternal border (generally)

113
Q

Rheumatic fever can lead to which valve abnormality?

A

Mitral stenosis

114
Q

Where is the murmur of mitral regurgitation the loudest?

A

At the apex

115
Q

Compare the pressures in the left ventricle and aorta in a patient with aortic stenosis with those in a healthy patient.

A

In a patient with aortic stenosis, the pressure in the left ventricle is higher than the pressure in the aorta; the ventricle squeezes blood past a stenotic valve, thus the pressure before the valve (the ventricle) is higher than the pressure after the valve (in the aorta)

116
Q

What are three examples of pathological processes that can cause mitral regurgitation?

A

Ischemic heart disease, mitral valve prolapse, and left ventricular dilatation

117
Q

What type of murmur is loudest at the apex and radiates toward the axilla?

A

Mitral valve murmurs

118
Q

What are two examples of pathological processes that can cause tricuspid regurgitation?

A

Right ventricular dilatation or endocarditis

119
Q

What type of murmur is loudest at the left sternal border at the fifth intercostal space and radiates to the right sternal border?

A

Tricuspid regurgitation

120
Q

A ventricular septal defect causes what type of murmur: late systolic, diastolic, or holosystolic?

A

Holosystolic

121
Q

Which heart valve disease process can be associated with syncope?

A

Aortic stenosis

122
Q

What type of murmur is holosystolic, harsh sounding, and loudest at the left sternal border at the fifth intercostal space?

A

Ventricular septal defect

123
Q

Which heart murmur is described as a holosystolic, high-pitched, blowing murmur?

A

Mitral regurgitation

124
Q

Murmurs due to valvular defects on the right side of the heart _____ (decrease/increase) in intensity on inspiration.

A

Increase

125
Q

Which heart murmur is described as a late systolic murmur with midsystolic click?

A

Mitral prolapse

126
Q

What is the most frequent murmur-causing valvular lesion?

A

Mitral prolapse

127
Q

Which heart murmur is described as an immediate high-pitched, blowing, diastolic murmur?

A

Aortic regurgitation

128
Q

Which heart murmur is usually benign, but can predispose to infective endocarditis?

A

Mitral prolapse

129
Q

Which heart murmur can be accompanied by a wide pulse pressure?

A

Aortic regurgitation

130
Q

Which heart murmur follows an opening snap?

A

Mitral stenosis

131
Q

What are three examples of pathological processes that can cause aortic regurgitation?

A

Aortic root dilatation, bicuspid aortic valve, or rheumatic fever

132
Q

Which heart murmur is described as a continuous, machine-like murmur?

A

Patent ductus arteriosus

133
Q

Which heart murmur is described as a delayed, rumbling, late-diastolic murmur?

A

Mitral stenosis

134
Q

Which heart chamber has the greatest increase in pressure above normal in a patient with mitral stenosis?

A

Left atrium

135
Q

What does the term pulsus parvus et tardus mean?

A

Pulses are weak, and the strongest part of the peripheral pulse occurs late after the S1 is heard; this is because it takes a longer time for blood to cross the stenotic aortic valve to fill the vessels

136
Q

Which heart murmur is described as a crescendo-decrescendo systolic murmur following an ejection click?

A

Aortic stenosis

137
Q

To where does the aortic stenosis murmur radiate?

A

The carotid arteries

138
Q

When a cardiac defect occurs on the left side of the heart, does the intensity of the corresponding murmur generally increase or decrease upon expiration?

A

Increase

139
Q

What causes the increase in intensity upon expiration of a left-sided cardiac defect?

A

Increased blood flow into the left atrium

140
Q

Match each of these conditions with one of the Starling curves: exercise; congestive heart failure (CHF); CHF plus digitalis

A

(A) exercise;

(B) CHF plus digitalis;

(C) CHF

141
Q

What phase of the cardiac cycle is the period of highest O2 consumption?

A

(1) isovolumetric contraction: the period between mitral valve closure and aortic valve opening

142
Q

What phase of the cardiac cycle corresponds to number (2)?

A

Systolic ejection: the period during which the aortic valve is open

143
Q

What phase of the cardiac cycle corresponds to number (4)?

A

Rapid filling: right after the mitral valve opens

144
Q

An asymptomatic 55-year-old woman has this electrocardiogram on a routine preoperative exam. Why are beats “missing”?

A

She has Mobitz type I (Wenckebach) second-degree atrioventricular block; the PR interval progressively lengthens until a beat is “dropped”

145
Q

A 35-year-old man presents with palpitations and lightheadedness and has this electrocardiogram. What is he at risk for?

A

He has Mobitz type II second-degree atrioventricular block, which can progress to complete (third-degree) heart block

146
Q

A 57-year-old man complains of crushing chest pain. He has this electrocardiogram in the ER. Compare the atrial and ventricular rates.

A

He has 3rd-degree (complete) atrioventricular block; the atrial rate is faster than the ventricular rate

147
Q

A 64-year-old has crushing chest pain radiating to his L arm. He becomes unresponsive; electrocardiogram is as shown. Diagnosis? Treatment?

A

Ventricular fibrillation; CPR and defibrillation are the only treatments for this otherwise fatal arrhythmia