Lecture 5.2: heart Flashcards
List the 6 causes of heart problems
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
What is the most common of the 6 causes of heart problems?
Failure of the pump
What are the 2 types of “failure of the pump”? Define each
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
What is obstruction of flow? Give examples
Something is in the way!
1) Systemic hypertension
2) Valvular calcification
3) Lesion in the heart
What causes regurgitant flow? Explain
1) Blood flows backward through the valve
2) Increases the volume workload of the heart and overwhelms the pumping capacity of the affected chambers
What is shunted flow? What are the two types? Give examples
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.
What occurs during disorders of conduction?
Uncoordinated cardiac impulses; dangerous arrhythmias keep the heart from contracting uniformly, thus it can’t pump blood
1) What can cause rupture of the heart or vessel?
2) What can rupture of the heart lead to?
1) Catastrophic event that puts a hole in the heart
2) Massive blood loss, hypotensive shock, death
List 3 ways to regulate HF besides the Frank-Starling mechanism
1) Neural humoral systems
2) Natriuretic peptide
3) Renin-angiotensin
Mechanisms to regulate HF:
1) Describe neural-humoral systems
2) Describe natriuretic peptides
3) Describe renin-angiotensin
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
True or false: Normally there’s no respiratory effects in right-sided HF
True; body fills with blood instead
True or false: isolated right-sided HF is less common
True
How does blood get to a fetus’s right atrium?
1) Oxygenated comes from placenta
2) Enters baby through umbilical vein
3) Tracks to the vena cava
4) Enters right atrium
Describe the two paths of blood through fetal circulation from the right atrium to systemic circulation
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
Deoxygenated blood from a fetus returns to placenta how?
Umbilical arteries
Congenital heart disease:
1) Define it
2) What causes it? When?
3) How common?
4) Etiology?
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
Describe left-to-right shunts
Increases pulmonary blood flow, increasing pressure and volume of pulmonary circulation, causing right ventricular hypertrophy
Describe right to left shunts
Pulmonary circulation is bypassed, and poorly oxygenated blood enters systemic circulation causing **blueness of the skin (cyanosis)*
Describe congenital obstruction
Decreased vascular flow caused by narrowing (stenosis) or complete blockage or absence (atresia) of the heart chambers, valves, or major blood vessels
Describe Eisenmenger Syndrome
Left to right shunt that builds pulmonary hypertension and reverses the flow to right-to-left
VSDs:
1) Where are they?
2) Radiation?
3) Intensity?
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.
ASDs:
1) Location?
2) Radiation?
3) Intensity?
1) Upper left sternal border
2) To the back Intensity.
3) Variable, usually grade II–III/VI Quality. Ejection but without the harsh quality
PDAs
1) Location?
2) Radiation?
3) Intensity?
4) Quality?
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
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?
1) Back to the body through the aorta!
2) Back to the lungs!
What are the 5 T’s of Congenital Heart Disease?
1) Tetralogy of Fallot
2) TGA
3) TAPVC (total anomalous pulmonary venous connection)
4) Truncus arteriosus
5) Tricuspid valve (atresia, stenosis, displacement)
Ischemic Heart Disease (IHD):
1) Define
2) What is usually the cause?
3) What is it the leading cause of ?
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
What are the four basic clinical syndromes of IHD?
1) Angina pectoris
2) Acute MI
3) Chronic IHD
4) Sudden cardiac death
1) Define angina pectoris
2) What are the 3 kinds?
1) Intermittent chest pain caused by transient, reversible myocardial ischemia
2) Stable, unstable, and prinzmetal anginas
Describe each of the 3 kinds of angina pectoris
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
Reperfusion Following Acute MI:
1) What is the goal?
2) How is this achieved?
3) What type of shock can develop post-MI? Explain
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)
What are some clinical features of MIs?
Chest pain and SOB
Myocardial Infarction (MI) prognosis:
1) What does it depend on?
2) What is long-term prognosis especially dependent on?
3) What is the mortality?
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
Chronic Ischemic Heart Disease:
1) What is it also called?
2) What is it?
1) Ischemic cardiomyopathy
2) Progressive heart failure from ischemic myocardial damage (often there is a history of MI)
Chronic Ischemic Heart Disease:
1) Why is the heart enlarged?
2) What can develop?
3) What is common? What account for many deaths?
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
Sudden Cardiac Death (SCD):
1) What is it?
2) Epidemiology?
3) What does it result from?
4) What is the most common cause?
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
SCD:
1) What causes are more common in young victims? Give an example
2) What improves prognosis markedly?
1) Nonatherosclerotic causes
-Long-QT (LQT) syndrome: caused by mutations in various cardiac ion channel genes (1 in 5,000)
2) Implantable cardioverter defibrillator
Valvular heart disease:
1) What is it?
2) Define stenosis
3) Define insufficiency
4) Is it one valve or multiple?
1) Stenosis and/or regurgitation (insufficiency)
2) Failure to open completely
3) Failure to close completely
4) Can affect single or multiple valves
Valvular heart disease:
1) What produces murmurs?
2) What account for two-thirds of all valve disease?
3) What does outcome depend on?
1) Abnormal blood flow through diseased valves
2) Acquired stenoses of aortic and mitral valves
3) Severity and speed of development
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?
1) Most patients are asymptomatic
2) Mitral valve regurgitation
3) CHF
4) Infective endocarditis and sudden death from ventricular arrhythmias
Infective Endocarditis:
1) What is it?
2) What does it destroy & what does this cause?
3) What are the Sx?
4) Complications?
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
Infective Endocarditis: What are the 2 types? Describe each
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
Cardiomyopathies:
1) What are they?
2) What are some causes?
1) Diverse group of disorders in which there is intrinsic myocardial dysfunction
2) Many different causes; genetic, acquired, and idiopathic
Cardiomyopathies: what are the 3 clinical/ functional classifications?
1) Dilated cardiomyopathy (90% of cases)
2) Hypertrophic cardiomyopathy
3) Restrictive cardiomyopathy (least common)
What makes up 90% of cardiomyopathies?
Dilated cardiomyopathies
Dilated cardiomyopathy:
1) What % of cardiomyopathies is this?
2) What happens?
3) When does it occur?
4) What % are dead within 2 yrs?
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
Hypertrophic Cardiomyopathy (HCM):
1) What is it?
2) What does it look like?
1) Massive myocardial hypertrophy without ventricular dilation
2) Ventricular septum bulges into the left ventricular outflow tract, and the left atrium is enlarged
Hypertrophic Cardiomyopathy (HCM):
1) What is it also called?
2) What occurs?
3) What occurs with abt 25% of cases?
1) Myocardial hypertrophy
2) Myocardium does not relax, so there is abnormal diastolic filling
3) Ventricular outflow obstruction by anterior leaflet of mitral valve
Hypertrophic Cardiomyopathy (HCM):
1) Describe the ventricle and its stroke volume
2) What are almost all cases caused by?
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
Hypertrophic Cardiomyopathy (HCM):
1) What does it cause?
2) What are the Sx?
3) Tx?
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
Restrictive Cardiomyopathy:
1) What is it?
2) What can cause it?
1) Ventricle wall is stiffer, impairing filling during diastole
2) Idiopathic or secondary to systemic disease (amyloidosis, hemochromatosis, sarcoidosis)
Restrictive Cardiomyopathy:
1) Sx?
2) Tx?
3) Mortality?
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
Myocarditis:
1) What is it?
2) Most common cause in US?
3) What are other causes?
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
Clinical spectrum of myocarditis is broad, but give some characteristics
1) Asymptomatic
2) Fatigue, dyspnea, palpitations, pain, fever
3) Acute heart failure
4) Dilated cardiomyopathy
Cardiac Tumors:
1) Are they common?
2) What is the most common heart tumor?
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
Cardiac Tumors:
1) Are primary cardiac tumors common?
2) Are they often malignant?
3) What is the most common primary cardiac tumor?
4) Tx?
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
