Z Cardio A&p

Front 1

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

Back 1

Tricuspid regurgitation

Front 2

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

Back 2

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

Front 3

By what mechanism does aldosterone increase cardiac output and mean arterial pressure?

Back 3

Aldosterone works in the kidneys to increase blood volume (and thus cardiac output)

Front 4

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

Back 4

Rapid filling

Front 5

Which organ has the greatest arteriovenous oxygen concentration difference and why?

Back 5

The heart, because oxygen extraction is always approximately 100%

Front 6

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

Back 6

Aortic root dilatation, bicuspid aortic valve, or rheumatic fever

Front 7

By what mechanism does activation of the renin-angiotensin system cause an increase in mean arterial pressure?

Back 7

By production of angiotensin II and aldosterone, which cause increased total peripheral resistance and increased blood volume, respectively

Front 8

An 80-year-old male with a history of right-sided heart failure presents with bilateral ankle edema. In terms of capillary fluid exchange, what is the mechanism by which he developed his edema?

Back 8

Heart failure results in increased capillary pressure, which causes fluid to move out of the capillaries and into the interstitial space

Front 9

An electrocardiogram shows P waves and QRS complexes that have no temporal relation to each other. The atrial rate is faster than the ventricular rate. What is the most likely diagnosis?

Back 9

Third degree (complete) atrioventricular block

Front 10

What is the physiologic benefit of the atrioventricular delay?

Back 10

It allows time for ventricular filling

Front 11

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

Back 11

Increase

Front 12

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

Back 12

Isovolumetric relaxation

Front 13

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

Back 13

Paradoxical

Front 14

The right coronary artery supplies the posterior septum via which coronary artery?

Back 14

The posterior descending artery

Front 15

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

Back 15

The operating point of the heart

Front 16

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

Back 16

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

Front 17

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

Back 17

Aortic stenosis

Front 18

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

Back 18

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

Front 19

What are the most dangerous sequelae of torsades des pointes?

Back 19

Ventricular fibrillation and death

Front 20

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

Back 20

Mitral prolapse

Front 21

What causes the S4 heart sound or "atrial kick"?

Back 21

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

Front 22

Patients with Wolff-Parkinson-White syndrome are at higher risk for which type of arrhythmia?

Back 22

Supraventricular tachycardia

Front 23

What does the term pulsus parvus et tardus mean?

Back 23

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

Front 24

The lack of voltage-gated sodium channels in pacemaker cells results in what effect on cardiac conduction?

Back 24

A slowed conduction velocity through the atrioventricular node to prolong transmission from the atria to the ventricles

Front 25

What is the normal pressure for the aorta during systole and diastole?

Back 25

<130 / 90 mmHg

Front 26

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

Back 26

The left sternal border (generally)

Front 27

Does pregnancy increase or decrease stroke volume?

Back 27

Increase

Front 28

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

Back 28

Catecholamines increase contractility

Front 29

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

Back 29

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)

Front 30

What happens during phase 0 of the cardiac myocyte action potential?

Back 30

Rapid depolarization due to increased sodium permeability

Front 31

By what mechanism do catecholamines cause an increase in contractility?

Back 31

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

Front 32

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

Back 32

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

Front 33

Which heart valve disease process can be associated with syncope?

Back 33

Aortic stenosis

Front 34

Which pressures, when increased, have a tendency to cause fluid to move into the capillaries and out of tissue?

Back 34

Interstitial fluid pressure and plasma colloid osmotic pressure

Front 35

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

Back 35

Pulmonic

Front 36

Define torsades des pointes.

Back 36

A ventricular tachycardia that is characterized by shifting sinusoidal waves on an electrocardiogram; a literal translation is, "twisting of the points"

Front 37

What is the effect of extracellular calcium entering the cardiac myocyte?

Back 37

Calcium release from the cardiac muscle sarcoplasmic reticulum (calcium-induced calcium release); and the resulting muscle contraction

Front 38

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

Back 38

Contraction of the atrium

Front 39

By what mechanism does angiotensin II increase blood pressure?

Back 39

Angiotensin II causes vasoconstriction

Front 40

On an electrocardiogram, what does the PR segment represent? How long is a normal PR interval?

Back 40

Conduction delay through the atrioventricular node; normally less than 200 msec

Front 41

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?

Back 41

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

Front 42

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

Back 42

Systolic

Front 43

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

Back 43

Increase

Front 44

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

Back 44

S2 splitting

Front 45

What is the most frequent murmur-causing valvular lesion?

Back 45

Mitral prolapse

Front 46

A 55-year-old male with long-standing alcoholic cirrhosis presents with bilateral pedal edema and ascites. In terms of capillary fluid exchange, what is the mechanism by which he developed his edema?

Back 46

Liver failure results in decreased plasma proteins, which decreases plasma colloid oncotic pressure, and in turn causes fluid to move out of the capillaries and into the interstitial space

Front 47

Which blood vessels account for most of total peripheral resistance?

Back 47

Arterioles

Front 48

A 25-year-old athlete begins training for the Olympics. As she runs her standard 3 miles, is the increased oxygen demand of the heart met by increased coronary blood flow or increased extraction of oxygen?

Back 48

Increased coronary blood flow; the heart always operates with maximal oxygen extraction

Front 49

In what part of the cardiac cycle do the coronary arteries fill?

Back 49

Diastole

Front 50

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

Back 50

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

Front 51

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

Back 51

Decrease; this is known as paradoxical splitting

Front 52

During which phase is ventricular volume lowest?

Back 52

During isovolumetric relaxation

Front 53

Which pressures, when increased, have a tendency to cause fluid to move out of the capillaries and into tissue?

Back 53

Capillary fluid pressure and interstitial fluid colloid osmotic pressure

Front 54

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

Back 54

Systolic ejection

Front 55

Central chemoreceptors respond to changes in the pH and the partial pressure of carbon dioxide of the brain interstitial fluid, which in turn are influenced by what?

Back 55

Arterial carbon dioxide

Front 56

What happens during phase 3 of the cardiac myocyte action potential?

Back 56

Rapid repolarization due to potassium efflux that returns the cell to a more negative potential

Front 57

To where does the aortic stenosis murmur radiate?

Back 57

The carotid arteries

Front 58

During phase 4 of the action potential in a ventricular myocyte, to which ion is the membrane highly permeable?

Back 58

Potassium; as a result, the resting potential of the cell is close to that of potassium

Front 59

What is the Bundle of Kent?

Back 59

An accessory conduction pathway from atria to ventricles, which bypasses the atrioventricular node; occurring in Wolff-Parkinson-White syndrome

Front 60

Which ion channels cause the automaticity of cardiac nodal cells?

Back 60

If channels cause the cells to spontaneously depolarize

Front 61

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

Back 61

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

Front 62

A 67-year-old male presents with an irregularly irregular electrocardiogram tracing at a routine doctor's visit. Which drug can decrease his risk of stroke? Which drug can control his heart rate?

Back 62

Warfarin (Coumadin) to prevent thromboembolism and β-blockers or calcium channel blockers to control heart rate

Front 63

_____ (Preload/Afterload) = mean arterial pressure.

Back 63

Afterload

Front 64

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

Back 64

Systole

Front 65

Does increasing contractility increase or decrease myocardial oxygen demand?

Back 65

Increase

Front 66

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

Back 66

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

Front 67

What is the equation for net filtration pressure?

Back 67

Net filtration pressure = [(capillary pressure - interstitial fluid pressure) - (plasma colloid osmotic pressure - interstitial fluid colloid osmotic pressure)]

Front 68

Which organ has the highest blood flow per gram of tissue?

Back 68

The kidney

Front 69

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

Back 69

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

Front 70

Which coronary artery supplies the posterior left ventricle?

Back 70

Circumflex artery

Front 71

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

Back 71

Nitroglycerin decreases preload by causing venodilation

Front 72

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.

Back 72

Increase; increase

Front 73

What would a patient with excess fluid outflow into the interstitium present with?

Back 73

Swelling (edema)

Front 74

Which coronary artery supplies the right ventricle?

Back 74

Acute marginal artery (from the right coronary artery)

Front 75

By what mechanism does activation of the sympathetic nervous system cause an increase in mean arterial pressure?

Back 75

By activation of β-1 and α-1 receptors, which cause an increase in cardiac output and total peripheral resistance, respectively

Front 76

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

Back 76

Mitral valve murmurs

Front 77

Which internal organ gets the largest share of the systemic cardiac output?

Back 77

The liver

Front 78

During what phase of the cardiac myocyte action potential does extracellular calcium enter the cell?

Back 78

The plateau phase

Front 79

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

Back 79

Preload and cardiac output

Front 80

Cardiac myocytes in which locations have pacemaker action potentials?

Back 80

The sinoatrial and the atrioventricular nodes

Front 81

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

Back 81

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

Front 82

Congenital long QT syndromes can be associated with what other pathology?

Back 82

Severe congenital sensorineural hearing deficit (Jervell and Lange-Nielsen syndrome)

Front 83

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

Back 83

Total resistance = R1 + R2 + R3...

Front 84

What is the characteristic electrocardiogram finding of first-degree atrioventricular block?

Back 84

Prolonged PR interval (> 200 msec) with no lengthening of the interval and no dropped beats

Front 85

In tricuspid stenosis, the murmur gets louder with _____ (inspiration/expiration) due to increased blood flow into the right atrium.

Back 85

Inspiration

Front 86

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

Back 86

S4

Front 87

What is the voltage value of the resting potential of a ventricular myocyte?

Back 87

- 85 mV; the value is maintained by the sodium/potassium pump and high permeability to potassium

Front 88

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

Back 88

Elevated jugular venous pressure

Front 89

Changes in which two parameters of brain interstitial fluid affect the response of central chemoreceptors?

Back 89

pH and the partial pressure of carbon dioxide

Front 90

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

Back 90

Increased blood flow into the left atrium

Front 91

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

Back 91

Preload

Front 92

Stroke volume = end-diastolic volume - _____ _____.

Back 92

End-systolic volume

Front 93

Does digitalis increase or decrease contractile strength?

Back 93

Increase

Front 94

How does acidosis affect contractility?

Back 94

Acidosis decreases contractility

Front 95

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

Back 95

Ventricular septal defect

Front 96

In the lungs, what is the physiologic advantage of vasoconstriction in response to hypoxia?

Back 96

The mechanism allows for only well-ventilated areas to remain perfused, optimizing gas exchange

Front 97

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

Back 97

Diastole

Front 98

Which heart sound occurs during aortic and pulmonary valve closure?

Back 98

S2

Front 99

Which abnormal heart sound occurs during rapid ventricular filling?

Back 99

S3

Front 100

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

Back 100

By causing an increase in wall tension

Front 101

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

Back 101

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

Front 102

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

Back 102

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

Front 103

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

Back 103

Decrease

Front 104

What is the electrocardiogram finding pathognomonic for Wolff-Parkinson-White syndrome and what does it signify?

Back 104

A delta wave, which signifies partial early depolarization of the ventricles via an accessory pathway

Front 105

In third-degree heart block, the atrial rate is _____ (slower/faster) than the ventricular rate.

Back 105

Faster

Front 106

What is meant by autoregulation of blood flow?

Back 106

The method by which blood flow to an organ remains constant over a wide range of blood pressures

Front 107

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

Back 107

55%

Front 108

Pulse pressure is proportional to what other cardiac parameter?

Back 108

Stroke volume

Front 109

What is the normal pulmonary capillary wedge pressure?

Back 109

<12 mmHg

Front 110

Rheumatic fever can lead to which valve abnormality?

Back 110

Mitral stenosis

Front 111

In patients with Wolff-Parkinson-White syndrome, what does the delta wave on electrocardiogram represent?

Back 111

Early depolarization of the ventricle due to the accessory conduction pathway (bundle of Kent), which bypasses the atrioventricular node

Front 112

Which local metabolite(s) govern autoregulation of perfusion of the heart?

Back 112

Oxygen, adenosine, and nitric oxide

Front 113

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

Back 113

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

Front 114

Does sympathetic stimulation increase or decrease contractility of the heart?

Back 114

Increase

Front 115

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

Back 115

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

Front 116

What chemical changes of blood elicit a response from peripheral chemoreceptors? How do central chemoreceptors differ?

Back 116

Low PO2, (< 60 mmHg), high PCO2, and low pH of blood; central chemoreceptors are not sensitive to oxygen

Front 117

If the right coronary artery supplies the inferior portion of the left ventricle via the posterior descending artery is the heart right or left dominant?

Back 117

Right dominant

Front 118

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

Back 118

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

Front 119

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?

Back 119

Increase

Front 120

How does acetylcholine affect the rate of diastolic depolarization and heart rate?

Back 120

It decreases the rate of diastolic depolarization (the slope of phase 4 of the action potential) and thus decreases heart rate

Front 121

Which factor governs autoregulation of perfusion of the skin?

Back 121

Sympathetic stimulation

Front 122

What is the spatial relationship among the three structures located inside the carotid sheath?

Back 122

The internal jugular vein is lateral, the common carotid artery is medial, and the vagus nerve is posterior

Front 123

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

Back 123

The value of the mean systemic pressure

Front 124

How does β1 blockade affect contractility and stroke volume?

Back 124

β1 blockade decreases contractility and stroke volume

Front 125

On an electrocardiogram, ventricular repolarization is represented by what?

Back 125

The T wave

Front 126

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

Back 126

Wide

Front 127

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

Back 127

Isovolumetric contraction

Front 128

Is first-degree atrioventricular block symptomatic or asymptomatic?

Back 128

Asymptomatic

Front 129

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.

Back 129

Increased; decreased

Front 130

What is Ohm's law?

Back 130

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

Front 131

What are the two main regulators that increase mean arterial pressure when it is low?

Back 131

Increased sympathetic tone and activation of the renin-angiotensin system

Front 132

What happens in phase 0 of the pacemaker action potential?

Back 132

Voltage-gated calcium channels open

Front 133

How long does the effective refractory period of the cardiac myocyte last?

Back 133

For the duration of the action potential until the cell returns to resting potential

Front 134

What is the dangerous sequela of atrial fibrillation?

Back 134

Atrial stasis leading to thrombosis, which can embolize and cause stroke

Front 135

What happens in phase 3 of the cardiac pacemaker action potential?

Back 135

Inactivation of the calcium channels and activation of the potassium channels

Front 136

Which local metabolites govern autoregulation of perfusion of the skeletal muscles?

Back 136

Lactate, adenosine, and potassium

Front 137

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?

Back 137

Increase

Front 138

On an electrocardiogram, what does the QRS complex represent? What is considered a normal QRS duration?

Back 138

Ventricular depolarization; normally less than 120 msec

Front 139

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

Back 139

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

Front 140

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

Back 140

Mitral prolapse

Front 141

Pulmonary capillary wedge pressure is a good approximation of the pressure of which chamber?

Back 141

The left atrium

Front 142

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

Back 142

Right ventricular dilatation or endocarditis

Front 143

Do circulating catecholamines increase or decrease contractility of the heart?

Back 143

Increase

Front 144

How is normal S2 splitting increased?

Back 144

By inspiration

Front 145

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

Back 145

Aortic regurgitation

Front 146

By what two mechanisms is a decrease in mean arterial pressure sensed?

Back 146

The medullary vasomotor center detects decreased baroreceptor firing; the juxtaglomerular apparatus in the kidney detects decreased renal perfusion

Front 147

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

Back 147

Holosystolic

Front 148

The aortic arch receptors transmit impulses to the medulla via which nerve? In response to which stimulus?

Back 148

Aortic receptor afferents travel via the vagus in response to only high blood pressure

Front 149

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

Back 149

Paradoxic splitting

Front 150

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

Back 150

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

Front 151

Which parameter does the viscosity of blood mostly depend on?

Back 151

Hematocrit

Front 152

Are peripheral or central chemoreceptors responsible for the Cushing reaction?

Back 152

Central chemoreceptors

Front 153

What happens during phase 1 of the cardiac myocyte action potential?

Back 153

Initial repolarization due to increased potassium permeability

Front 154

The carotid sinus receptors transmit impulses to the medulla via which nerve? In response to which stimuli?

Back 154

Carotid sinus receptor afferents travel via the glossopharyngeal nerve in response to both high and low blood pressure

Front 155

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

Back 155

Increase

Front 156

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

Back 156

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

Front 157

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

Back 157

The preload or the initial length of the cardiac muscle fiber

Front 158

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

Back 158

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

Front 159

What is the mechanism by which toxins, infections, and burns can cause edema?

Back 159

Any insults (eg, toxins, infections, or burns) that cause increased capillary permeability can cause an increase in the filtration constant (Kf) and subsequently cause fluid to move out of the capillaries and into the interstitial space

Front 160

On an electrocardiogram, what does the ST segment represent?

Back 160

The isoelectric state after the ventricles have been depolarized and before repolarization

Front 161

An electrocardiogram has an increasing PR interval with each successive beat until a QRS complex does not appear after a P wave. The next beat has a normal PR interval. What is the most likely diagnosis?

Back 161

Second-degree atrioventricular block, Mobitz type I (Wenckebach)

Front 162

What are the three variables that affect stroke volume?

Back 162

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

Front 163

A patient has a myocardial infarction that damages the anterior interventricular septum and the apex. Which coronary artery was occluded?

Back 163

The left anterior descending artery

Front 164

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

Back 164

S3

Front 165

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

Back 165

Left atrium

Front 166

A 75-year-old male with congestive heart failure presents with worsening shortness of breath. On physical exam he has a 3/6 diastolic murmur best heard in the fifth intercostal space in the midclavicular line and crackles in the bases of the lungs. What c

Back 166

This patient has mitral stenosis and one would expect the pulmonary capillary wedge pressure to be greater than the left ventricular diastolic pressure

Front 167

A 73-year-old female presents with an electrocardiogram tracing with a "sawtooth" pattern. Which three classes of drugs can be given to treat this condition?

Back 167

Class IA, IC, or III antiarrhythmics

Front 168

The pulmonary vasculature is unique in that _____ causes vasoconstriction whereas in other organs it causes vasodilation.

Back 168

Hypoxia

Front 169

What are the three structures located inside the carotid sheath?

Back 169

The internal jugular Vein, the common carotid Artery, and the vagus Nerve (remember the Mnemonic VAN)

Front 170

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.

Back 170

Decrease; decrease

Front 171

How is cardiac muscle different from skeletal muscle?

Back 171

Cardiac muscle action potential has a plateau due to calcium ion influx; cardiac nodal cells display automaticity by spontaneously depolarizing; and cardiac mycytes are electrically coupled via gap junctions

Front 172

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

Back 172

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

Front 173

Which form of second-degree atrioventricular block is more likely to progress to a third-degree block?

Back 173

Mobitz type II

Front 174

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

Back 174

Mitral regurgitation

Front 175

Which abnormal heart sound is associated with a hypertrophic ventricle?

Back 175

S4

Front 176

Which heart sound occurs during mitral and tricuspid valve closure?

Back 176

S1

Front 177

As compared with the myocardial action potential, which phases are absent from the pacemaker potential?

Back 177

Phases 1 and 2

Front 178

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.

Back 178

Increase; increase

Front 179

In what type of heart block do the atria and ventricles beat independently of each other?

Back 179

Third-degree heart block

Front 180

Which factors govern autoregulation of perfusion of the kidneys?

Back 180

Myogenic and tubuloglomerular feedback

Front 181

How do calcium channel blockers affect contractility and stroke volume?

Back 181

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

Front 182

A 65-year-old male presents with an electrocardiogram tracing that displays P waves and QRS complexes that occur independently of each other. Which therapeutic intervention would be most appropriate?

Back 182

Treatment with an implantable pacemaker

Front 183

What is the most posterior part of the heart?

Back 183

The left atrium

Front 184

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

Back 184

The left sternal border

Front 185

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

Back 185

Contractility

Front 186

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

Back 186

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

Front 187

Which coronary artery is most commonly occluded?

Back 187

The left anterior descending artery, which supplies the interventricular septum

Front 188

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

Back 188

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

Front 189

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

Back 189

Hydralazine decreases afterload by causing arterial dilation

Front 190

Cardiac output = stroke volume x _____ _____.

Back 190

Heart rate

Front 191

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

Back 191

Patent ductus arteriosus

Front 192

Given an electrocardiogram showing second-degree Mobitz type II heart block, how can the arrhythmia be further classified?

Back 192

By the ratio of P waves to QRS complexes (eg, 2:1 or 3:1)

Front 193

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

Back 193

Aortic stenosis

Front 194

What happens during phase 2 of the cardiac myocyte action potential?

Back 194

Electrical plateau due to equivalent calcium influx and potassium efflux

Front 195

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

Back 195

Decrease

Front 196

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

Back 196

Aortic regurgitation

Front 197

A 43-year-old female presents with bilateral pitting leg edema and lab results remarkable for high low-density lipoprotein, low albumin, and proteinuria (likely nephrotic syndrome). In terms of capillary fluid exchange, what is the mechanism by which she developed her edema?

Back 197

Nephrotic syndrome results in proteinuria and subsequent hypoalbuminemia, which decreases plasma colloid oncotic pressure, and in turn causes fluid to move out of the capillaries and into the interstitial space

Front 198

By what mechanism does activation of α-1 receptors cause an increase in mean arterial pressure?

Back 198

α-1 Receptor activation causes venoconstriction, which increases venous return and thus cardiac output; and arterial vasoconstriction, which causes an increase in total peripheral resistance

Front 199

What do U waves on an electrocardiogram represent?

Back 199

Hypokalemia or bradycardia

Front 200

An enlarged left atrium can cause which noncardiac symptoms?

Back 200

Dysphagia due to compression of the esophageal nerve and hoarseness due to compression of the recurrent laryngeal nerve

Front 201

In most cases, the sinoatrial and atrioventricular nodes are supplied by which coronary artery?

Back 201

The right coronary artery

Front 202

Atrial natriuretic peptide _____ (constricts/dilates) efferent renal arterioles, and _____ (constricts/dilates) afferent arterioles.

Back 202

Constricts; dilates; as a result, glomerular filtration rate is increased

Front 203

Where is the murmur of mitral regurgitation the loudest?

Back 203

At the apex

Front 204

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

Back 204

Isovolumetric contraction

Front 205

By what mechanism does activation of β-1 receptors cause an increase in cardiac output?

Back 205

Activation of β-1 receptors causes an increase in heart rate and contractility

Front 206

What is atrial natriuretic peptide?

Back 206

It is released from the atria in response to elevated pressure and causes vascular relaxation and diuresis in the kidneys

Front 207

What is the equation for ejection fraction?

Back 207

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

Front 208

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

Back 208

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

Front 209

What is the normal pressure for the right ventricle during systole and diastole?

Back 209

<25 / <5 mmHg

Front 210

During which phase is ventricular volume highest?

Back 210

During atrial systole

Front 211

Which rhythm on electrocardiogram is classically described as having an irregularly irregular pattern with no discrete P waves?

Back 211

Atrial fibrillation

Front 212

What is Fick's principle?

Back 212

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

Front 213

During the pacemaker action potential, the slope of which phase determines the heart rate?

Back 213

Phase 4

Front 214

What is the main risk factor for torsades des pointes?

Back 214

Prolongation of the QT interval, usually due to drug adverse effects or genetic syndromes

Front 215

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

Back 215

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

Front 216

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

Back 216

The aortic valve

Front 217

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

Back 217

Diastole and systole, respectively

Front 218

Which local metabolite(s) determine autoregulation of perfusion of the brain?

Back 218

Carbon dioxide (or pH)

Front 219

What is Cushing's triad?

Back 219

Cushing's triad is the triad of hypertension, bradycardia, and respiratory depression in response to ischemia in the brain

Front 220

What happens during phase 3 of the cardiac myocyte action potential?

Back 220

Rapid repolarization due to increased permeability to potassium

Front 221

Sympathetic stimulation alters perfusion of the skin to control which aspect of homeostasis?

Back 221

Temperature control

Front 222

What is Cushing's reaction?

Back 222

The chain reaction that occurs in response to increased intracranial pressure. Increased intracranial pressure leads to arteriolar vasoconstriction, which causes cerebral ischemia, leading to a sympathetic response of hypertension, and ultimately resulting in reflex bradycardia

Front 223

Which ion channels in a pacemaker cell are permeable to sodium?

Back 223

If channels

Front 224

Ejection fraction = _____ _____ / end-diastolic volume.

Back 224

Stroke volume

Front 225

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

Back 225

Increase; increase

Front 226

What is the normal pressure for the left ventricle during systole and diastole?

Back 226

<130 / 10 mmHg

Front 227

An electrocardiogram shows dropped beats that are not preceded by a change in the length of the PR interval. What is the most likely diagnosis?

Back 227

Second degree atrioventricular block, Mobitz type II

Front 228

An electrocardiogram shows no identifiable waves. What is the most likely diagnosis?

Back 228

Ventricular fibrillation

Front 229

What happens in phase 4 of the cardiac pacemaker action potential?

Back 229

Slow diastolic depolarization due to increased permeability to sodium ion

Front 230

What is the normal pressure for the pulmonary artery during systole and diastole?

Back 230

<25 / 10 mmHg

Front 231

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

Back 231

Decrease; increased

Front 232

Which heart murmur follows an opening snap?

Back 232

Mitral stenosis

Front 233

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

Back 233

Mitral stenosis

Front 234

What is the normal pressure for the right atrium?

Back 234

<5 mmHg

Front 235

What segment of the electrocardiogram corresponds with the mechanical contraction of the ventricles?

Back 235

The QT interval

Front 236

The posterior descending artery that supplies the posterior septum arises from the circumflex artery in _____ (20%/50%/80%) of cases.

Back 236

20%; this is a left-dominant heart

Front 237

On an electrocardiogram, what does the P wave represent?

Back 237

Atrial depolarization

Front 238

An 80-year-old woman is in shock in the intensive care unit. The attending physician orders the determination of a pulmonary capillary wedge pressure. What instrument is used to perform this study?

Back 238

A Swan-Ganz catheter

Front 239

What is the etiology of congenital long QT syndromes?

Back 239

Most often they are due to defects in sodium or potassium channels

Front 240

Why does carotid massage cause bradycardia?

Back 240

Carotid massage causes increased pressure/stretch on the carotid artery, which causes the afferent baroreceptors to fire, which results in a decrease in heart rate

Front 241

What are the two equations for mean arterial pressure?

Back 241

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

Front 242

Which rhythm on electrocardiogram is described as having a "sawtooth" baseline?

Back 242

Atrial flutter

Front 243

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

Back 243

High; low

Front 244

In what part of the electrocardiogram is atrial repolarization?

Back 244

Atrial repolarization is masked within the QRS complex

Front 245

Sympathetic stimulation _____ (decreases/increases)the possibility that If channels are open.

Back 245

Increases; as a result, the pacemaker cell depolarizes more frequently and the heart beats faster

Front 246

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

Back 246

Diastole

Front 247

How does hypoxia affect contractility?

Back 247

Hypoxia causes a decrease in contractility and in stroke volume

Front 248

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

Back 248

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

Front 249

Which type of receptors are most important in causing the body's response to severe hemorrhage?

Back 249

Baroreceptors

Front 250

Which infectious disease can cause third-degree heart block?

Back 250

Lyme disease

Front 251

What type of murmur occurs in late systole after a midsystolic click and is loudest at S2?

Back 251

Mitral prolapse

Front 252

A 50-year-old Ethiopian male presents with severe bilateral leg and scrotal edema due to Elephantiasis (lymphatic obstruction caused by filarial nematodes). In terms of capillary fluid exchange, what is the mechanism by which he developed his edema?

Back 252

Lymphatic obstruction causes increased interstitial fluid colloid osmotic pressure, which causes fluid to move out of the capillaries and into the interstitial space

Front 253

The plateau in cardiac muscle action potential is caused by what?

Back 253

Calcium influx

Front 254

Does progressive lengthening of the PR interval take place in Mobitz type I, Mobitz type II, or both?

Back 254

Type I involves progressive lengthening followed by a dropped beat; in type II there are dropped beats without progressive lengthening

Front 255

What is the normal pressure for the left atrium?

Back 255

<12 mmHg

Front 256

How is net fluid flow calculated?

Back 256

Net fluid flow = (net filtration pressure) × (filtration constant for capillary permeability)

Front 257

Which murmur is often due to age-related calcification?

Back 257

Aortic stenosis

Front 258

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

Back 258

Reduced filling

Front 259

Describe the body's response after baroreceptors sense hypotension.

Back 259

Hypotension causes decreased arterial pressure/stretch, which decreases afferent baroreceptor firing, increases efferent sympathetic firing, and decreases efferent parasympathetic stimulation, all of which cause vasoconstriction, increased heart rate, contractility, and blood pressure

Front 260

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.

Back 260

Increase; decrease; increase

Front 261

The filtration constant for capillary permeability is denoted by what symbol?

Back 261

Kf

Front 263

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

Back 263

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