Cardiovascular Part 1 Flashcards
Define Ischemic Heart Disease
A collective term used to refer to various diseases characterized by inability of the coronary arteries to deliver adequate oxygen to meet the needs of the myocardium
What is by far the leading cause of ischemic heart disease?
Coronary artery disease (CAD)
(also known as coronary heart disease [CHD] or atherosclerosis of the coronary arteries)
What is atherosclerosis characterized by?
the formation of elevated plaques called atheromas in the intima of coronary arteries
What may atheromas progress to?
calcification, ulceration with thrombosis, and intraplaque hemorrhage
There is significant evidence linking atherosclerosis to what?
hyperlipidemia, particularly hypercholesterolemia (elevated serum cholesterol levels)
What are other causes of ischemic heart disease?
- Thromboemboli
- Coronary artery vasospasm
- Conditions that increase cardiac work load and oxygen demand
What are the major clinical manifestations of ischemic heart disease?
- Chronic ischemic heart disease
- Angina pectoris
- Myocardial infarction
What is the most common clinical form of the ischemic heart disease
Chronic ischemic heart disease (stable ischemic heart disease)
What is the clinical progression of chronic ischemic heart disease?
- often initially clinically silent (asymptomatic)
- may eventually lead to the insidious onset of (predominantly left-sided) congestive heart failure, and is also associated with a significantly increased risk of angina pectoris, myocardial infarction, or sudden cardiac death
What is angina pectoris?
A syndrome of episodic, paroxysmal, substernal or precordial chest pain or discomfort resulting from myocardial ischemia
Three distinct forms of angina pectoris
- Stable (classic) angina
- Unstable angina (also known as pre-infarction angina*)
- Variant angina
What is stable angina caused by?
a fixed coronary artery obstruction secondary to atherosclerosis
What are signs and symptoms of stable (classic) angina?
Episodic, paroxysmal, substernal or precordial pressure, heaviness, pain or discomfort usually brought on by exertion and relieved by rest or nitrates (nitroglycerin)
Stable angina attacks are of ______ (usually no longer than 15 to 20 minutes), are _____ and usually follow a _____ that is associated with a temporary increase in demands on the heart
- limited duration
- predictable
- precipitating event
How are stable angina symptoms relieved?
by decreasing the cardiac metabolic demand (i.e., rest from exertion) or by administration of nitroglycerin
What is unstable angina (pre-infarction angina)?
Attacks occur more frequently, are longer, and produce more severe symptoms than those in stable angina. The anginal pain also is more easily provoked and may occur at rest
the symptoms of unstable angina are often indistinguishable from
those of non-ST segment elevation myocardial infarction (NSTEMI)
patients experiencing symptoms of unstable angina usually require medical evaluation / hospitalization to rule-out ______
NSTEMI
(non-ST segment elevation myocardial infarction)
Unstable angina is usually defined by the presence of least one of three features:
(1) Anginal pain occurs at rest (or with minimal exertion) and usually lasting longer than 20 minutes
(2) Anginal pain is severe, and of new onset
(3) Anginal pain that occurs with a crescendo pattern
What is variant angina also known as?
Prinzmetal’s angina or vasospastic angina
What is the most important mechanism in variant angina?
Coronary artery vasospasm, with or without superimposed CAD
What are some signs and symptoms of variant angina?
Chest pain/discomfort is very similar or identical to that described in stable (classic) angina, but occurs at rest
What is Myocardial infarction (MI)
a clinical syndrome characterized by symptoms of myocardial ischemia, persistent electrocardiographic (ECG) changes, and release of biomarkers of myocardial necrosis resulting from an insufficient supply of oxygenated blood to an area of the heart
What is myocardial infarction (MI) a result of?
irreversible myocardial injury, occurring as a result of prolonged ischemia.
What is the underlying cause of MI?
The underlying cause essentially always is a complete interruption of regional myocardial blood flow
MI most frequently involves the _____ ventricle
left
What is the leading cause of MI?
Coronary artery atherosclerosis
The initiating factor in most cases of MI is what?
sudden disruption of partially occlusive coronary artery atherosclerotic plaque
What are some mechanisms of injury that cause Coronary artery atherosclerosis
- Rupture, fissuring, or ulceration of plaques
- hemorrhage into the core of plaques
How are MI commonly classified?
- The degree of ventricular wall involvement
- The location of the infarct within the heart or the specific artery involved:
- The presence or absence of ST segment elevation on the ECG
______ infarctions involve the full thickness of the ventricle. They typically result in _____ elevation on the ECG
- Transmural
- ST segment
Subendocardial infarctions are MIs limited to the _____ of the myocardium
inner-third
What type of infarct is most common in MI?
Infarcts resulting from a blockage of the left anterior descending coronary artery are most common
T/F MI associated with (ST segment elevation) MI (STEMI) are more common and should be distinguished from non-ST segment elevation MI (NSTEMI)
True
What is acute myocardial infarction (AMI)
used for MIs characterized by profound, acute transmural myocardial ischemia affecting relatively large areas of myocardium and associated with ST segment elevation on the ECG
What is the pathogenesis of Myocardial Infarction (MI)? (5 steps)
- An atheromatous plaque is suddenly disrupted
- Platelets adhere, aggregate, and are activated
- Growing (propagating) thrombus
- thrombus can evolve to completely occlude the coronary artery lumen
- Myocardial necrosis begins at approximately 30 minutes after occlusion of a coronary artery
What does the gross and microscopic appearance of an MI depends on?
The age of the injury
In MI, areas of damage progress through a highly characteristic sequence of morphologic changes from ______, to acute and then chronic _____, to ________
- coagulative necrosis
- inflammation
- fibrosis
What does myocardial necrosis proceed to?
proceeds invariably to scar formation without any significant regeneration
What is Acute MI most often characterized by?
a sudden onset of chest pain that is similar to the pain of angina but is more severe and prolonged, generally lasting more than 15 to 20 minutes, and is unrelieved by nitroglycerin
Specific symptoms of myocardial infarction include:
- Premonitory pain
- Pain of infarction
- Other associated symtoms
How many patients of MI have premonitory pain?
One-third of patients give a history of alteration in the pattern of angina, recent onset of typical or atypical (unstable) angina, or unusual “indigestion” or pressure or squeezing felt in the chest.
When do most infarctions of AMI occur? What is the most common symotpom?
- Most infarctions occur at rest
- chest pain/discomfort
______ has little effect in reliving chest pain in an AMI
Nitroglycerin
What are associated symptoms of AMI?
- cold sweat (diaphoresis)
- feel weak and apprehensive
- Light-headedness
- syncope
- dyspnea
- orthopnea
- cough
- wheezing
- nausea and vomiting
- abdominal bloating
AMIs may also be ______ (“silent”) or have _____ (unrecognized) symptomatology
- painless
- atypical
Who is more prone to painless or atypical MI?
Elderly patients, female patients and those with diabetes
the diagnosis of MI has rested on the triad of what?
(1) ischemic-type chest discomfort
(2) ECG abnormalities, and
(3) elevated serum cardiac markers.
What has assumed the primary role in confirming the diagnosis of AMI
Serum cardiac markers (also called cardiac isoenzymes)
What have been shown to be specific indicators of MI and have gained acceptance as the primary diagnostic criterion for MI.
Cardiac-specific Troponins T and I (cTnT, cTnI)
T/F Creatine Kinase (CK) isoenzymes MB occurs in skeletal muscle and is therefore a specific indicator for necrosis, but has a 15% false positive rate
False
CK-MB occurs in cardiac muscle and is therefore a specific indicator for myocardial necrosis, but has a 15% false positive rate
What are other tests that can be used for the diagnosis of MI
- Coronary artery angiography (cardiac catheterization)
- Myocardial perfusion scintigraphy tests
What are complications of MI?
- Arrhythmias
- Progressive heart failure
- Ventricular aneurysm
- Mural thrombus / thromboembolism
- Rupture of the myocardium
- Fibrinous pericarditis
- Heart chamber dilation
What are the most common cause of sudden cardiac death in the first hour post-MI
Ventricular arrhythmias, such as ventricular fibrillation
Infarction involving 40% or more of the left ventricle leads to what?
cardiogenic shock, which is the most common cause of death among in-hospital patients with acute MIs.
Stasis of blood within the aneurysm results in _____ thrombi
mural
When does Myocardial rupture tend to occur?
occur most frequently between 4 and 7 days postinfarction
After cardiogenic shock and arrhythmias, what is the most common cause of postinfarction death?
cardiac rupture, being responsible for up to 20% of all fatal MIs.
What is Acute coronary syndrome (ACS)
refers to a spectrum of clinical symptoms compatible with acute myocardial ischemia
What does acute coronary syndrome (ACS) include?
- unstable angina pectoris
- non-ST-segment elevation myocardial infarction (NSTEMI)
- ST-segment elevation myocardial infarction (STEMI) (or acute MI)
What is sudden cardiac death (SCD)
defined as unexpected death due to cardiac causes occurring in a short time period (generally within 1 hour of symptom onset) in a person with known or unknown cardiac disease
What is congestive heart failure?
Heart failure is a symptom complex, not a disease entity, that can result from a variety of cardiac disorders. Heart failure is characterized by inability of the heart to pump blood sufficiently to keep pace with the body’s circulatory demands
While the terms heart failure and congestive heart failure (CHF) are often used interchangeably, _____ more correctly denotes a volume-overloaded status
CHF
When does CHF develop?
when the body’s compensatory mechanisms (adaptations) to correct intravascular and interstitial volume overload and/or inadequate tissue perfusion (oxygenation) become overwhelmed and are no longer adequate
The heart can fail as a result of what?
any condition that causes impaired pump function (e.g., due to decreased myocardial contractility or decreased compliance) or increased cardiac work demands
What is the etiology of CHF? (4)
- Decreased myocardial function or cardiac valvular dysfunction
- Increased vascular resistance
- Increased blood volume
- Excessive metabolic demand
CHF is classified in different ways for clinical purposes. How are they classified?
- Systolic versus diastolic heart failure
- Left- versus right-sided heart failure
- Backward versus forward failure
In _____ heart failure, there is reduced cardiac contractility
systolic
in _____ heart failure there is impaired cardiac relaxation and abnormal ventricular filling
diastolic
What is the most common cause of CHF
Left ventricular (LV) systolic dysfunction
(about 60% of patients)
What is Diastolic heart failure / diastolic LV dysfunction due to?
impaired ventricular relaxation and is usually related to chronic hypertension or ischemic heart disease
What is left sided heart failure
refers to the signs and symptoms caused by failure of the left ventricle or excessive pressure in the left atrium
(i.e., clinical features of pulmonary congestion)
What is right sided heart failure?
refers to the signs and symptoms caused by failure of the right ventricle or excessive pressure in the right atrium
(i.e., clinical features of systemic venous congestion)
What is the leading cause of right sided heart failure?
left-sided heart failure
What is biventricular failure?
failure of both ventricles, usually is not simultaneous but develops over time due to the increased stress placed on the remaining ventricle
What is an index of cardiac pump function?
it is an index of heart strength in the clinical setting
What is the most frequently used index of cardiac pump function in CHF?
the (cardiac) ejection fraction (EF)
What is the ejection fraction equation?
EF = 100 × systolic volume (SV) / EDV
Where is ejection fraction normally measured?
Clinically, ejection fraction is usually measured only in the left ventricle
What is a normal adult left ventricular ejection fraction?
~ 0.50 (50%) to 0.70 (70%)
Patients with ejection fractions of # 0.40 (40%) are considered to have what
systolic dysfunction
T/F It is impossible to have symptomatic CHF with a normal EF
False
It is possible to have symptomatic CHF with a normal EF
(known as heart failure with preserved ejection fraction [HFpEF]):
What are clinical symptoms of left sided heart failure?
- exertional dyspnea
- dyspnea at rest
- orthopnea
- paroxysmal nocturnal dyspnea
- cough
- hemoptysis
What does passive pulmonary congestion lead to? What color is the sputum?
- pulmonary edema
- sputum may be rust colored due to the presence of many hemosiderin-laden alveolar macrophages (“heart-failure cells”)
What is cor pulmonale?
right ventricular enlargement due to pulmonary hypertension
Clinical manifestations of right-sided heart failure are?
most common signs are related to systemic venous congestion and include:
- jugular venous distention
- enlarged and tender liver and spleen
- ascites
- pitting edema of the extremities
Gross cardiac abnormalities vary depending on what
the underlying disease process.
In CHF, typically the left ventricle usually is _____ and/or can be dilated, sometimes massively
hypertrophied
What are some lung abnormalities in CHF?
The lungs are heavy and boggy due to pulmonary congestion and edema
The subsequent breakdown of RBCs and hemoglobin leads to what?
the appearance of hemosiderin-laden alveolar macrophages (so-called “heart failure cells”)
What is congenital heart disease?
A gross structural abnormality of the heart or intrathoracic great vessels that is present at birth and that is actually or potentially of functional significance.
What are chromosomal abnormalities that are sometimes associated with CHD
- Turner syndrome (XO) is associated coarctation of the aorta.
- Down syndrome (trisomy 21) is associated with atrial and ventricular septal defects and atrioventricular valve deformities
There is an apparent increase what during pregnancy while living at high altitude
in the incidence of patent ductus arteriosus
T/F Rubella (German measles) infection is a prominent cause of CHD
true
Cardiac malformations are especially frequent and the cardiac abnormality most frequently found in _____ , is a combination of pulmonary artery stenosis and patent ductus arteriosus
rubella syndrome
CHD can classified according to the presence or absence of what
cyanosis
What does Non-cyanotic CHD include
those with a left-to-right shunt (e.g., patent ductus arteriosus, atrial or ventricular septal defect)
What does cyanotic CHD include
include transposition of the great vessels, malformations with a right-to-left shunt (e.g., the tetralogy of Fallot), and disorders in which a left-to-right shunt reverses flow to right-to-left because of increased pulmonary arterial pressure (pulmonary artery hypertension)
Obstructive lesions of non-cyanotic CHD include what
coarctation of the aorta and (congenital) aortic stenosis
What is Atrial septal defect (ASD)
A hole from a septum secundum or septum primum defect in the interatrial septum normally produces a modest left-to-right, non-cyanotic shunt
What are morphologic abnormalities of atrial septal defects?
- Ostium secundum ASDs (75% of ASDs)
- Ostium primum ASDs (~ 15 - 20% of ASDs)
- Sinus venosus: (~ 5-10% of ASDs)
infants with very large ASDs may develop what?
Heart failure
are usually the main presenting symptoms of unresolved large ASDs as the left ventricle becomes increasingly overburdened
Exertional fatigue and dyspnea
The incidence of ____ (especially _____) is high in patients with ASDs
- atrial arrhythmias
- atrial fibrillation
What is Patent foramen ovale (PFO)
A flaplike opening between the atrial septa primum and secundum at the location of the fossa ovalis that persists after age 1 year
When does PFO have clinical significance
When it occasionally leads to paradoxical embolism* and are a possible cause of cryptogenic strokes in patients under age 55 years.
Normally, the left atrial pressure keeps the PFO flap closed, but transient _____ blood flow can occur, such as with Valsalva-type maneuvers
right-to-left
What is a Ventricular septal defect (VSD)
A hole within the membranous or muscular portions of the intraventricular septum that produces a left-to-right, non-cyanotic shunt
What is the most common congenital heart disease?
Ventricular septal defect (VSD)
In infants, larger VSDs may cause what?
tachypnea, tachycardia and heart failure
In adults, unresolved VSDs eventually produce symptoms associated with leftsided heart failure including what?
shortness of breath, orthopnea, and dyspnea on exertion
If left untreated by surgery, what may VSDs progress to?
pulmonary artery hypertension, gradual rightsided heart failure.
In unresolved VSDs, with the advent of pulmonary hypertension, the shunt will begin to _____ flow
reverse (to right-to-left blood shunting)
What is Patent ductus arteriosus (PDA)
Failure of closure of the fetal ductus arteriosus
What is Coarctation of the aorta
Narrowing or constriction of the aorta
Morphologic narrowing of coarctation of the aorta can be what in relation to the ductus arteriosus?
preductal (“infantile”) or postductal (“adult”)
What is usually present in preductal coarctation of the aorta
patent ductus arteriosus (PDA)
What is the preductal (infantile) clinical presentation of Coarctation of the aorta?
cyanosis localized to the lower half of the body
What is the postductal (adult) clinical presentation of Coarctation of the aorta?
hypertension is limited to the upper extremities and cerebral vessels
What is a Tetralogy of Fallot (TOF)
the most common form of cyanotic [right-to-left shunt] CHD
What are the following 4 major features of Tetralogy of Fallot?
- Obstruction of the right ventricular outflow tract
- Concentric right ventricular hypertrophy
- Ventricular septal defect (VSD)
- Dextroposition of the aorta
What causes Obstruction of the right ventricular outflow tract in a TOF
subpulmonic stenosis, pulmonary valve stenosis or complete atresia
What is the clinical presentation of TOF
creates a right-to-left shunt that leads to cyanosis
What are Transposition of the great arteries (TGA)
The aorta arises from the right ventricle and the pulmonary artery emanates from the left ventricle
What is needed for extrauterine survival in Transposition of the great arteries (TGA)
A compensatory anomaly such VSD, ASD, or PDA with right-to-left shunting
What clinical presentation occurs in TGA?
Prominent and progressive cyanosis
