A 18-year-old IV drug user presents with fever. He has a new murmur and lesions on his fingers (as shown). What is most likely responsible?
Staphylococcus aureus; the patient has splinter hemorrhages
Is Staphylococcus aureus bacterial endocarditis rapid or insidious in onset?
Rapid; it has a high virulence and results in large vegetations on previously normal valves
What is the most common cause of early cyanotic heart disease?
Tetralogy of Fallot
Do right-to-left shunts cause early or late cyanosis?
Early; much of the circulation bypasses the lungs and is not oxygenated
Do left-to-right shunts cause early or late cyanosis?
Late; cyanosis does not occur until the effects of increased pulmonary pressure become significant
A patent ductus arteriosus can be closed by using what drug?
Indomethacin, although surgery is sometimes required as well
What is the order of frequency for the three most common causes of left-to-right shunts?
Ventricular septal defects, atrial septal defects, patent ductus arteriosus
What is Eisenmengers syndrome?
In Eisenmengers syndrome, a left-to-right shunt overloads the pulmonary circulation and causes increasing pulmonary pressures. When pulmonary pressures equal systemic pressures, the shunt switches to right-to-left and cyanosis ensues
The 5 Ts of right-to-left (cyanotic) shunts in congenital heart disease are comprised of which diseases?
Tetralogy of Fallot, Transposition of the great arteries, Truncus arteriosus, Tricuspid atresia, and TAPVR (total anomalous pulmonary venous return)
What are the heart sounds associated with atrial septal defect?
A loud S1 and a wide, fixed split S2
What is persistent truncus arteriosus?
Failure of the aorticopulmonary septum to divide the embryonic truncus arteriosus into the pulmonary trunk and the aorta
What is tricuspid atresia?
Absence of the tricuspid valve and a hypoplastic right ventricle
How do neonates with tricuspid atresia remain viable given their severely compromised circulation?
In order to maintain viability, both an atrial septal defect and a ventricular septal defect are required for babies with tricuspid atresia
What is total anomalous pulmonary venous return?
A disorder in which the pulmonary veins drain into right heart circulation (ie, the superior vena cava or carotid sinus) as opposed to the left atrium
How can an uncorrected ventricular septal defect, atrial septal defect, or patent ductus arteriosus result in progressive pulmonary hypertension?
They can cause compensatory vascular hypertrophy, which results in progressive pulmonary hypertension
Which congenital heart diseases can eventually result in Eisenmengers syndrome?
Uncorrected atrial septal defect, ventricular septal defect, or patent ductus arteriosus
What are two physical findings associated with Eisenmengers syndrome?
Clubbing and polycythemia; both are due to hypoxia secondary to right-to-left shunting
In which direction is blood shunted in Eisenmengers syndrome? How does the condition change over time?
As pulmonary hypertension increases, the original left-to-right shunt reverses into a right-to-left shunt
Tetralogy of Fallot is caused by the displacement of what structure during embryogenesis?
The infundibular septum; it is displaced anteriorly and superiorly
Name the four clinical features of tetralogy of Fallot.
Pulmonary stenosis, Right ventricular hypertrophy, Overriding aorta, and Ventricular septal defect (remember: PROVe)
In patients with tetralogy of Fallot, the severity of which heart lesion determines the patients prognosis?
Pulmonary stenosis
In tetralogy of Fallot, why does right-to-left shunting occur?
Because the increased pressure in the right ventricle (caused by the stenotic pulmonic valve) causes the blood to be shunted through the path of least resistance (ie, to the left ventricle through the ventricular septal defect)
How does squatting help patients with tetralogy of Fallot improve their symptoms?
Squatting compresses femoral arteries, which causes increased arterial pressure, which in turn reduces right-to-left shunting and causes more blood from the right ventricle to enter the pulmonary circulation
What is the chest x-ray finding that is associated with tetralogy of Fallot?
A boot-shaped heart, which is due to right ventricular hypertrophy
What is the prognosis for infants with D-transposition of great vessels?
They die within the first few months of life if their condition is not surgically corrected by adding a shunt
What is D-transposition of great vessels?
A congenital heart disease characterized by an aorta that leaves the right ventricle (anteriorly) and a pulmonary artery that leaves the left ventricle (posteriorly), causing separation of pulmonary and systemic circulations
What condition must be present for a fetus with D-transposition of great vessels to remain viable?
The presence of a shunt to allow adequate mixing of pulmonary and systemic blood (ie, a ventricular septal defect, atrial septal defect, or patent foramen ovale)
In terms of embryology, what is the cause of D-transposition of great vessels?
Failure of the embryonic aorticopulmonary septum to spiral
What cardiac valvular disease can result from coarctation of the aorta?
Aortic regurgitation
What is the difference between infantile and adult types of coarctation of the aorta?
Infantile type occurs when the aortic stenosis is proximal to the insertion of the ductus arteriosus (preductal), and adult type occurs when the aortic stenosis is distal to the ductus arteriosus (postductal) (remember: INfantile IN close to the heart and ADult type Distal to the Ductus)
What physical exam findings are associated with adult type coarctation of the aorta?
Notched ribs due to increased collateral circulation, hypertension in the upper extremities, and weak pulses in the lower extremities
What two congenital or genetic diseases are associated with coarctation of the aorta?
Bicuspid aortic valve and Turners syndrome
What is the direction of blood flow across the ductus arteriosus before and after birth?
During the fetal period of patent ductus arteriosus the shunt is right to left, and during the neonatal period the shunt is left to right
How would one describe the murmur of patent ductus arteriosus?
Continuous, machine-like murmur
The ductus arteriosus remains patent due to which two factors?
Prostaglandin E synthesis and low oxygen tension
Which drug can be used to close a patent ductus arteriosus?
Indomethacin (remember: ENDomethacin (indomethacin) ENDs patency of PDA)
Which drug can be used to maintain a patent ductus arteriosus?
Prostaglandin E (remember: PGEE kEEps it open)
What is the pathogenesis of left-to-right shunting in neonates with patent ductus arteriosus?
During the neonatal period, lung resistance decreases and, as a result, the previous right-to-left shunt during the fetal period turns into a left-to-right shunt
What is the dangerous structural sequela of patent ductus arteriosus?
The persistent left-to-right shunt eventually results in right ventricular hypertrophy and heart failure
Which genetic disorder is associated with truncus arteriosus and tetralogy of Fallot?
22q11 deletion syndromes
Which genetic syndrome is associated with endocardial cushion defects?
Down syndrome
Which viral disease is associated with septal defects, patent ductus arteriosus, and pulmonary artery stenosis?
Congenital rubella
Which syndrome is associated with coarctation of the aorta?
Turners syndrome
Marfans syndrome is associated with what cardiovascular defect?
Aortic insufficiency (as a late complication)
The offspring of a diabetic mother are at increased risk of what congenital cardiac defect?
Transposition of the great vessels
Which three cardiac defects are associated with Down syndrome?
Atrial septal defect, ventricular septal defect, and atrioventricular septal defect
What is the definition of hypertension in an adult?
Blood pressure 140/90 mmHg or above
Which racial group has the greatest risk for developing hypertension: African-Americans, whites, or Asians?
African-Americans
Secondary hypertension is most commonly a sequela of disease of which organ?
The kidney
What are five risk factors for hypertension?
Increased age, obesity, diabetes, smoking, genetics
What is the most common type of hypertension?
Essential (primary) hypertension, which is the cause of 90% of cases of hypertension
Hypertension predisposes a person to which pathologic disease processes?
Atherosclerosis, left ventricular hypertrophy, stroke, congestive heart failure, renal failure, retinopathy, and aortic dissection
What is an atheroma?
A sign of hyperlipidemia that is described as plaques in the blood vessels
What is a xanthoma?
A sign of hyperlipidemia that is described as plaques or nodules composed of lipid-laden histiocytes in the skin
Tendinous xanthomas are classically found in which tendon?
The Achilles tendon
What is a corneal arcus?
A lipid deposit in the cornea that appears as lightening of the iris
What is the name of a xanthoma that occurs on the eyelid?
Xanthelasma
An 80-year-old veteran is told by his physician that he has calcification of his radial arteries and that it is a relatively benign condition. What is the name of this disease?
Mönckeberg arteriosclerosis
What is atherosclerosis?
A type of arteriosclerosis that involves fibrous plaques and atheromas in the intima of the arteries
What is arteriolosclerosis? What diseases is it associated with?
Arteriosclerosis is described as hyaline thickening of the small arteries; it is associated with essential hypertension
What arteriolar pathology is seen in malignant hypertension?
Hyperplastic onion skinning of arteries
What aortic pathology predisposes patients with Marfans syndrome to aortic dissection?
Patients with Marfans syndrome are predisposed to cystic medial necrosis, which puts them at risk for aortic dissection
A tall patient with long extremities, hyperextensive joints, and arachnodactyly presents to his physician for anticipatory guidance. For which cardiovascular pathology is he at increased risk?
Aortic dissection
A patient presents to the emergency department with tearing chest pain radiating to the back and dies soon after presentation. Upon autopsy, what vascular pathology would most likely be seen?
Longitudinal intraluminal tear forming a false lumen, indicative of aortic dissection
A patient presents to the emergency department with tearing chest pain radiating to the back. What would most likely be seen on x-ray of the chest?
Mediastinal widening, suggestive of aortic dissection
Which types of arteries are susceptible to atherosclerosis?
Elastic arteries as well as large and medium-sized muscular arteries
Name six possible complications of atherosclerosis.
Infarcts, peripheral vascular disease, thrombi, emboli, aneurysms, and ischemia
What are two symptoms of ischemia resulting from atherosclerosis?
Angina and claudication
What are five risk factors for atherosclerosis?
Smoking, hypertension, diabetes mellitus, hyperlipidemia, and family history
What is the pathogenesis of atherosclerosis?
Endothelial cell dysfunction causes macrophage and low-density lipoprotein accumulation, leading to foam cells and fatty streak formation, causing smooth muscle cell migration, which causes the formation of the fibrous plaques that become complex atheroma
List four common locations for atherosclerosis in order of most common to least common.
Abdominal Aorta, coronary artery, popliteal artery, carotid artery
What percentage of blockage must take place in the coronary arteries for angina to occur?
>75%
What are the characteristics of stable angina?
Chest pain occurring after a known duration of exercise
How does the etiology of Prinzmetals angina differ from other forms of angina?
Prinzmetals angina occurs as a result of coronary artery spasm
How does the etiology of unstable angina differ from stable angina?
Unstable angina occurs as a result of thrombosis and not necrosis of the coronary artery
Worsening chest pain at rest or with minimal exertion is termed what?
Unstable/crescendo angina
At what point is ischemic heart disease given the term myocardial infarction rather than unstable angina?
When acute thrombosis due to coronary artery atherosclerosis results in myocyte necrosis
What usually causes sudden cardiac death?
Lethal arrhythmia, such as ventricular fibrillation
By definition, how soon after the onset of symptoms do people die from sudden cardiac death?
Within 1 hour
What is chronic ischemic heart disease?
Progression to congestive heart failure over many years due to ischemic myocardial damage secondary to coronary atherosclerosis
Which type(s) of angina occur(s) at rest?
Prinzmetals variant and unstable angina
What electrocardiogram change is one likely to see with stable angina during an exercise stress test?
ST depression
What electrocardiogram change is one likely to see with Prinzmetals variant form of angina?
ST elevation
Which is the most common coronary artery to be occluded in the evolution of a myocardial infarction: circumflex, right coronary, or left anterior descending?
Left anterior descending
Which is the least common coronary artery to be occluded in the evolution of a myocardial infarction: circumflex, right coronary, or left anterior descending?
Circumflex
How long after a myocardial infarction does the infarcted myocardium show recanalized arteries?
7 weeks
How long after a myocardial infarction does the infarcted myocardium show extensive coagulative necrosis?
2-4 days
How long after a myocardial infarction does the tissue around the infarcted myocardium show acute inflammation?
2-4 days; the tissue has dilated vessels with neutrophil emigration into tissue
For what duration after a myocardial infarction does the infarcted myocardium appear unchanged on light microscopy?
In the first 2-4 hours
How long after a myocardial infarction does the infarcted myocardium first show contraction bands?
After 1-2 hours
How long after a myocardial infarction does early coagulative necrosis begin?
After 4 hours
During what period of time after a myocardial infarction is there the greatest risk for an arrhythmia?
At 2-4 days after a myocardial infarction
During what period of time after a myocardial infarction is there the greatest risk for ventricular aneurysm?
At 7 weeks after a myocardial infarction
Name nine possible symptoms of myocardial infarction.
Severe retrosternal pain, nausea, vomiting, pain in the left arm, diaphoresis, jaw pain, shortness of breath, fatigue, and adrenergic symptoms
Describe the gross appearance and coloring of the affected myocardium on the first day of a myocardial infarction.
On the first day of a myocardial infarction, the myocardium typically appears darkly mottled and pale with tetrazolium staining
Describe the gross appearance and coloring of the affected myocardium 2-4 days after a myocardial infarction.
At 2-4 days after a myocardial infarction, the myocardium typically appears hyperemic because of dilation of blood vessels
Describe the gross appearance and coloring of the affected myocardium 5-10 days after a myocardial infarction.
At 5-10 days after a myocardial infarction, the myocardium typically has a hyperemic myocardial infarction border with central yellow-brown softening, which becomes maximally yellow and soft by 10 days
Describe the appearance and coloring of the affected myocardium 7 weeks after a myocardial infarction.
At 7 weeks after a myocardial infarction, the myocardium typically appears gray-white, demonstrating a completely contracted scar
On a cellular level, what happens to the infarcted myocardium on the first day of myocardial infarction?
Release of intracellular contents of necrotic cells into the bloodstream and the start of neutrophil emigration; myocardial enzymes are detected in serum
What are four possible dangerous sequelae of myocardial infarction in the 5-10 after it occurs?
Free wall rupture, tamponade, papillary muscle rupture, interventricular septal rupture
During the first 6 hours after a myocardial infarction, what test is the gold standard for establishing the diagnosis?
Electrocardiogram
Which cardiac marker rises after 4 hours and remains elevated for 7-10 days after myocardial infarction?
Troponin I
Which protein marker is the most specific during the early stages of myocardial infarction?
Troponin I
In which tissue other than myocardium is creatine kinase-MB found?
Skeletal muscle
Aspartate aminotransferase is a nonspecific marker because it can be found in which three cell types?
Cardiac, liver, and skeletal muscle cells
An ST segment elevation on an electrocardiogram indicates what type of damage to the myocardium?
Transmural infarct
An ST segment depression on an electrocardiogram indicates what type of damage to the myocardium?
Subendocardial infarct
Pathologic Q waves on electrocardiogram indicate what type of damage to the myocardium?
Transmural infarct
Which cardiac protein peaks at 1 day following a myocardial infarction, and is absent by day 3?
Creatine kinase-MB
Which enzyme peaks between day 1 and 2 following a myocardial infarction, then gradually decreases?
Aspartate aminotransferase
Why is the subendocardium particularly susceptible to infarction?
Because there are few collaterals and high pressure
What electrocardiogram changes would you expect to see with transmural and subendocardial infarcts?
With transmural infarcts, one would expect to see ST elevations on electrocardiogram, whereas with subendocardial infarcts, one would expect to see ST depressions on electrocardiogram
Which complication is common during the first few days after a myocardial infarction?
Cardiac arrhythmia
Which complication of myocardial infarction can result in cardiac tamponade?
Ventricular wall rupture
Which complication of myocardial infarction can result in acute-onset severe mitral regurgitation?
Papillary muscle rupture
What is the cause of the friction rub that can be heard 3-5 days after myocardial infarction?
Fibrinous pericarditis
What three complications can result from aneurysm formation after a myocardial infarction?
Mural thrombus embolization, arrhythmia and decreased cardiac output
What is Dresslers syndrome?
An autoimmune syndrome resulting in fibrinous pericarditis several weeks after myocardial infarction
At 6 days after having a myocardial infarction, a patient presents with a new-onset murmur. What is the most likely murmur?
Holosystolic murmur of mitral regurgitation, best heard over the apex of the heart
What is the most common type of cardiomyopathy?
Dilated (congestive) cardiomyopathy
Which chemotherapeutic drug is a possible cause of dilated cardiomyopathy?
Doxorubicin
Which type of cardiomyopathy is peripartum cardiomyopathy?
Dilated cardiomyopathy
Which hematologic disorder can cause both dilated cardiomyopathy and restrictive/obliterative cardiomyopathy?
Hemochromatosis
Which septum becomes hypertrophied in hypertrophic cardiomyopathy?
The intraventricular septum
Which type of cardiomyopathy can cause young athletes to die suddenly?
Hypertrophic cardiomyopathy
Hypertrophic cardiomyopathy is treated with which two drug classes?
β-Blockers or heart-specific calcium channel blockers (ie, verapamil)
Which type of cardiomyopathy presents with an S4 heart sound and a systolic ejection murmur?
Hypertrophic cardiomyopathy
Name eight etiologies of dilated cardiomyopathy.
Chronic Alcohol abuse, wet Beriberi, Coxsackie B virus myocarditis, chronic Cocaine use, Chagas disease, Doxorubicin toxicity, hemochromatosis, and peripartum cardiomyopathy
Which extra heart sound is present in dilated cardiomyopathy?
S3
What is endocardial fibroelastosis?
Thick fibroelastic tissue found in the endocardium of affected children, which can lead to restrictive cardiomyopathy
Which cardiomyopathies present with diastolic dysfunction? Systolic dysfunction?
Restrictive and hypertrophic cardiomyopathies present with diastolic dysfunction, whereas dilated cardiomyopathies present with systolic dysfunction
Which type of cardiomyopathy can lead to outflow tract obstruction?
Hypertrophic cardiomyopathy, causing a hypertrophied interventricular septum that is too close to the mitral valve leaflet and blocks outflow through the aortic valve
What are six causes of restrictive cardiomyopathy?
Sarcoidosis, amyloidosis, radiation fibrosis, endocardial fibroelastosis, Loefflers syndrome, and hemochromatosis
What is Loefflers syndrome?
Endomyocardial fibrosis with a prominent eosinophilic infiltrate, which can lead to restrictive cardiomyopathy
What is the difference between the relation of sarcomeres in dilated vs hypertrophic cardiomyopathy?
In dilated cardiomyopathy, the sarcomeres are added in series (eccentric hypertrophy); in hypertrophic cardiomyopathy, the sarcomeres are added in parallel (concentric hypertrophy)
What is the inheritance pattern of familial hypertrophic cardiomyopathy? In 50% of cases, what is the etiology of hypertrophic cardiomyopathy?
Autosomal dominant; 50% of cases are familial
Which type of cardiomyopathy is associated with Friedreichs ataxia?
Hypertrophic cardiomyopathy; patients with Friedreichs ataxia commonly die of cardiac pathology
A 16-year-old male presents for a school physical. On physical exam, you discover a 2/6 systolic murmur at the left sternal border. Upon questioning he says that he has had several fainting episodes. His father, a former Italian soccer player, had similar episodes and died suddenly at the age of 25 years. What is this patients likely diagnosis? What is the histologic appearance of his cardiac biopsy?
Hypertrophic cardiomyopathy; the histologic appearance is disoriented, tangled, hypertrophied myocardial fibers
In congestive heart failure, _____ (increased/decreased) cardiac output leads to _____ (increased decreased) activity of renin-angiotensin-aldosterone, which leads to ________ (increased/decreased) systemic venous pressure, and ultimately the physical finding of _____ _____.
Decreased; increased; increased; peripheral edema
In congestive heart failure, _____ (increased/decreased) left ventricular contractility leads to ______ (increased/decreased) pulmonary venous pressure, ultimately leading to _____ _____.
Decreased; increased; pulmonary edema
In congestive heart failure, _____ (increased/decreased) left ventricular contractility leads to _____ (increased/decreased) pulmonary venous pressure, which can eventually lead to _______ (increased/decreased) right ventricular output, and ultimately the physical finding of _____ _____.
Decreased; increased; decreased; peripheral edema
If there is a failure of left ventricular output to increase during exercise, what is the physical symptom that emerges?
Dyspnea on exertion
Which line corresponds to troponin I?
(A) troponin I rises four hours after myocardial infarction and is elevated for 7-10 days
Which cardiac enzyme corresponds to line (C)?
Creatine kinase-MB; it peaks at one day after a myocardial infarction and is absent by day three
A 45-year-old woman with a history of syncopal events has this MRI. If the pathology arises from the heart, what is most likely diagnosis?
Myxoma, the most common primary tumor of the heart
A 45-year-old man takes disopyramide for arrhythmia. Which of the lines shows the effect of this class of meds on cardiac action potential?
(1) class IA antiarrhythmics increase the action potential duration, increase the effective refractory period, and increase the QT interval
