Lecture 5.2: heart

Question 1

List the 6 causes of heart problems

Answer 1

1) Failure of the pump
2) Obstruction to flow
3) Regurgitant flow
4) Shunted Flow
5) Disorders of cardiac conduction
6) Rupture of the heart or major vessel

Question 2

What is the most common of the 6 causes of heart problems?

Answer 2

Failure of the pump

Question 3

What are the 2 types of “failure of the pump”? Define each

Answer 3

1) Systolic dysfunction: The cardiac muscle contracts weakly and chambers can’t empty properly
2) Diastolic dysfunction: Muscle can not relax or open completely and thus doesn’t fill

Question 4

What is obstruction of flow? Give examples

Answer 4

Something is in the way!
1) Systemic hypertension
2) Valvular calcification
3) Lesion in the heart

Question 5

What causes regurgitant flow? Explain

Answer 5

1) Blood flows backward through the valve
2) Increases the volume workload of the heart and overwhelms the pumping capacity of the affected chambers

Question 6

What is shunted flow? What are the two types? Give examples

Answer 6

1) Inappropriate diversion of blood from one chamber to another, or one vessel to another
2) May be congenital or acquired
3) VSD, ASD, PDA, tetralogy of Fallot, transposition of the great arteries, etc.

Question 7

What occurs during disorders of conduction?

Answer 7

Uncoordinated cardiac impulses; dangerous arrhythmias keep the heart from contracting uniformly, thus it can’t pump blood

Question 8

1) What can cause rupture of the heart or vessel?
2) What can rupture of the heart lead to?

Answer 8

1) Catastrophic event that puts a hole in the heart
2) Massive blood loss, hypotensive shock, death

Question 9

List 3 ways to regulate HF besides the Frank-Starling mechanism

Answer 9

1) Neural humoral systems
2) Natriuretic peptide
3) Renin-angiotensin

Question 10

Mechanisms to regulate HF:
1) Describe neural-humoral systems
2) Describe natriuretic peptides
3) Describe renin-angiotensin

Answer 10

1) Norepinephrine increases heart rate and augments myocardial contractility and vascular resistance
2) Diuresis and vascular smooth muscle relaxation
3) Water and salt retention increases vascular tone

Question 11

True or false: Normally there’s no respiratory effects in right-sided HF

Answer 11

True; body fills with blood instead

Question 12

True or false: isolated right-sided HF is less common

Answer 12

True

Question 13

How does blood get to a fetus’s right atrium?

Answer 13

1) Oxygenated comes from placenta
2) Enters baby through umbilical vein
3) Tracks to the vena cava
4) Enters right atrium

Question 14

Describe the two paths of blood through fetal circulation from the right atrium to systemic circulation

Answer 14

1) Path 1:
Passes through foramen ovale
Enters left atrium
Passes the mitral valve
Enters left ventricle
Pumps to aorta and systemic circulation
2) Path 2:
Passes tricuspid valve
Enters right ventricle
Pumps to pulmonary artery
Passes through ductus arteriosus
Enters aorta
Enters systemic circulation

Question 15

Deoxygenated blood from a fetus returns to placenta how?

Answer 15

Umbilical arteries

Question 16

Congenital heart disease:
1) Define it
2) What causes it? When?
3) How common?
4) Etiology?

Answer 16

1) Abnormalities of heart/great vessels present from birth
2) Faulty embryogenesis, weeks 3-8
3) Approximately 1% of live births
4) Cause unknown in 90% of cases

Question 17

Describe left-to-right shunts

Answer 17

Increases pulmonary blood flow, increasing pressure and volume of pulmonary circulation, causing right ventricular hypertrophy

Question 18

Describe right to left shunts

Answer 18

Pulmonary circulation is bypassed, and poorly oxygenated blood enters systemic circulation causing **blueness of the skin (cyanosis)*

Question 19

Describe congenital obstruction

Answer 19

Decreased vascular flow caused by narrowing (stenosis) or complete blockage or absence (atresia) of the heart chambers, valves, or major blood vessels

Question 20

Describe Eisenmenger Syndrome

Answer 20

Left to right shunt that builds pulmonary hypertension and reverses the flow to right-to-left

Question 21

VSDs:
1) Where are they?
2) Radiation?
3) Intensity?

Answer 21

1) Lower left sternal border
2). Little
3) Variable, only partially determined by the size of the shunt.
-Small shunts with a high-pressure gradient may have very loud murmurs.
-Large defects with elevated pulmonary vascular resistance may have no murmur.

Question 22

ASDs:
1) Location?
2) Radiation?
3) Intensity?

Answer 22

1) Upper left sternal border
2) To the back Intensity.
3) Variable, usually grade II–III/VI Quality. Ejection but without the harsh quality

Question 23

PDAs
1) Location?
2) Radiation?
3) Intensity?
4) Quality?

Answer 23

1) Upper left sternal border and to left
2) Sometimes to the back
3) Varies depending on size of the shunt, usually grade II–III/VI.
4) A rather hollow, sometimes machinery-like murmur that is continuous throughout the cardiac cycle

Question 24

TGA:
1) Oxygen poor blood enters the R heart and is pumped where?
2) Oxygen rich blood from the lungs enters the L heart and is pumped where?

Answer 24

1) Back to the body through the aorta!
2) Back to the lungs!

Question 25

What are the 5 T’s of Congenital Heart Disease?

Answer 25

1) Tetralogy of Fallot 2) TGA 3) TAPVC (total anomalous pulmonary venous connection) 4) Truncus arteriosus 5) Tricuspid valve (atresia, stenosis, displacement)

Question 26

Ischemic Heart Disease (IHD): 1) Define 2) What is usually the cause? 3) What is it the leading cause of ?

Answer 26

1) Generic designation for a group of related syndromes resulting from myocardial ischemia Cardiac blood supply (perfusion) cannot meet myocardial oxygen demand 2) Decreased coronary artery blood flow (“coronary artery disease”) 3) Leading cause of death in the United States

Question 27

What are the four basic clinical syndromes of IHD?

Answer 27

1) Angina pectoris 2) Acute MI 3) Chronic IHD 4) Sudden cardiac death

Question 28

1) Define angina pectoris 2) What are the 3 kinds?

Answer 28

1) Intermittent chest pain caused by transient, reversible myocardial ischemia 2) Stable, unstable, and prinzmetal anginas

Question 29

Describe each of the 3 kinds of angina pectoris

Answer 29

1) Stable angina: episodic pain on exertion; narrowing (≥75%) of one or more coronary arteries 2) Unstable angina: increasing pain at rest; plaque disruption and thrombosis 3) Prinzmetal angina: pain at rest; coronary artery spasm of unknown etiology

Question 30

Reperfusion Following Acute MI: 1) What is the goal? 2) How is this achieved? 3) What type of shock can develop post-MI? Explain

Answer 30

1) Therapeutic goal in acute MI is to salvage ischemic tissue by reperfusion 2) Reperfusion achieved by thrombolysis, stent placement, or coronary artery bypass graft CABG 3) Cardiogenic shock can develop following massive MI (>40% of left ventricle)

Question 31

What are some clinical features of MIs?

Answer 31

Chest pain and SOB

Question 32

Myocardial Infarction (MI) prognosis: 1) What does it depend on? 2) What is long-term prognosis especially dependent on? 3) What is the mortality?

Answer 32

Depends on infarct size, site, and thickness of heart wall damage 2) Quality of left ventricular function and the extent of vascular obstruction in vessels that supply the remaining healthy myocardium 3) Overall 1 year mortality is 30%; 3-4% mortality per year thereafter

Question 33

Chronic Ischemic Heart Disease: 1) What is it also called? 2) What is it?

Answer 33

1) Ischemic cardiomyopathy 2) Progressive heart failure from ischemic myocardial damage (often there is a history of MI)

Question 34

Chronic Ischemic Heart Disease: 1) Why is the heart enlarged? 2) What can develop? 3) What is common? What account for many deaths?

Answer 34

1) Left ventricular dilation and hypertrophy of remaining viable myocardium 2) Severe progressive heart failure 3) Arrhythmias are common; arrhythmias and MIs account for many deaths

Question 35

Sudden Cardiac Death (SCD): 1) What is it? 2) Epidemiology? 3) What does it result from? 4) What is the most common cause?

Answer 35

1) Unexpected death from cardiac causes without symptoms (or within 24 hr of symptom onset) 2) Affects about 400,000 each year in U.S. 3) Fatal arrhythmia 4) Coronary atherosclerosis

Question 36

SCD: 1) What causes are more common in young victims? Give an example 2) What improves prognosis markedly?

Answer 36

1) Nonatherosclerotic causes -Long-QT (LQT) syndrome: caused by mutations in various cardiac ion channel genes (1 in 5,000) 2) Implantable cardioverter defibrillator

Question 37

Valvular heart disease: 1) What is it? 2) Define stenosis 3) Define insufficiency 4) Is it one valve or multiple?

Answer 37

1) Stenosis and/or regurgitation (insufficiency) 2) Failure to open completely 3) Failure to close completely 4) Can affect single or multiple valves

Question 38

Valvular heart disease: 1) What produces murmurs? 2) What account for two-thirds of all valve disease? 3) What does outcome depend on?

Answer 38

1) Abnormal blood flow through diseased valves 2) Acquired stenoses of aortic and mitral valves 3) Severity and speed of development

Question 39

Mitral valve prolapse: 1) What are the Sx? 2) What may it progress to? 3) What may 3% have if the chordae or valve leaflets rupture? 4) What is there an increased risk of?

Answer 39

1) Most patients are asymptomatic 2) Mitral valve regurgitation 3) CHF 4) Infective endocarditis and sudden death from ventricular arrhythmias

Question 40

Infective Endocarditis: 1) What is it? 2) What does it destroy & what does this cause? 3) What are the Sx? 4) Complications?

Answer 40

1) Bacterial invasion of heart valves, endocardium 2) Destroys heart tissue: large, friable vegetations 3) Fever and flu-like symptoms 4) Septicemia, arrhythmias, renal failure, systemic emboli

Question 41

Infective Endocarditis: What are the 2 types? Describe each

Answer 41

1) Acute endocarditis: highly virulent pathogen attacks normal valve -half of patients dead within days to weeks 2) Subacute endocarditis: low virulence pathogen colonizes abnormal valve -slow onset, long course, most recover

Question 42

Cardiomyopathies: 1) What are they? 2) What are some causes?

Answer 42

1) Diverse group of disorders in which there is intrinsic myocardial dysfunction 2) Many different causes; genetic, acquired, and idiopathic

Question 43

Cardiomyopathies: what are the 3 clinical/ functional classifications?

Answer 43

1) Dilated cardiomyopathy (90% of cases) 2) Hypertrophic cardiomyopathy 3) Restrictive cardiomyopathy (least common)

Question 44

What makes up 90% of cardiomyopathies?

Answer 44

Dilated cardiomyopathies

Question 45

Dilated cardiomyopathy: 1) What % of cardiomyopathies is this? 2) What happens? 3) When does it occur? 4) What % are dead within 2 yrs?

Answer 45

1) 90% of cardiomyopathies in this category 2) Heart dilates, enlarges, ineffective contraction 3) Any age, mainly 20 to 50 years Slowly progressing CHF 4) 50% of patients

Question 46

Hypertrophic Cardiomyopathy (HCM): 1) What is it? 2) What does it look like?

Answer 46

1) Massive myocardial hypertrophy without ventricular dilation 2) Ventricular septum bulges into the left ventricular outflow tract, and the left atrium is enlarged

Question 47

Hypertrophic Cardiomyopathy (HCM): 1) What is it also called? 2) What occurs? 3) What occurs with abt 25% of cases?

Answer 47

1) Myocardial hypertrophy 2) Myocardium does not relax, so there is abnormal diastolic filling 3) Ventricular outflow obstruction by anterior leaflet of mitral valve

Question 48

Hypertrophic Cardiomyopathy (HCM): 1) Describe the ventricle and its stroke volume 2) What are almost all cases caused by?

Answer 48

1) Ventricle is thick-walled, heavy, and hyper-contracting, but has reduced stroke volume 2) Missense mutations in at least 12 genes that encode the sarcomeric proteins that form the contractile apparatus of striated muscle

Question 49

Hypertrophic Cardiomyopathy (HCM): 1) What does it cause? 2) What are the Sx? 3) Tx?

Answer 49

1) Reduced cardiac output and secondary increase in pulmonary venous pressure 2) Exertional dyspnea, atrial fibrillation, CHF, arrhythmia, sudden death 3) Drugs to promote ventricular relaxation or surgical excision of part of septum

Question 50

Restrictive Cardiomyopathy: 1) What is it? 2) What can cause it?

Answer 50

1) Ventricle wall is stiffer, impairing filling during diastole 2) Idiopathic or secondary to systemic disease (amyloidosis, hemochromatosis, sarcoidosis)

Question 51

Restrictive Cardiomyopathy: 1) Sx? 2) Tx? 3) Mortality?

Answer 51

1) Cough, shortness of breath, fatigue, peripheral edema 2) Not often helpful; may be candidates for a heart transplant 3) 70% of patients die within 5 years

Question 52

Myocarditis: 1) What is it? 2) Most common cause in US? 3) What are other causes?

Answer 52

1) Inflammation of myocardium causes injury 2) Viral infections are most common cause in U.S. Coxsackie viruses A and B 3) Many nonviral infectious causes

Question 53

Clinical spectrum of myocarditis is broad, but give some characteristics

Answer 53

1) Asymptomatic 2) Fatigue, dyspnea, palpitations, pain, fever 3) Acute heart failure 4) Dilated cardiomyopathy

Question 54

Cardiac Tumors: 1) Are they common? 2) What is the most common heart tumor?

Answer 54

1) Tumors of the heart are rare (5% of pt deaths) 2) Most common tumor of the heart is a metastatic tumor from another tissue Most often from lung, lymphoma, breast

Question 55

Cardiac Tumors: 1) Are primary cardiac tumors common? 2) Are they often malignant? 3) What is the most common primary cardiac tumor? 4) Tx?

Answer 55

1) Primary tumors of the heart are very uncommon 2) 80% to 90% of all primary tumors are benign 3) Most common primary tumor is a myxoma, which usually occurs in the left atrium 4) Echocardiography; surgical resection