CARDIOMYOPATHIES Flashcards
Which type of cardiomyopathy is characterized by an ejection fraction of usually less than 30% when symptoms are severe?
A) Restrictive cardiomyopathy
B) Hypertrophic cardiomyopathy
C) Dilated cardiomyopathy
D) All of the above
Answer:
C) Dilated cardiomyopathy
Rationale: Dilated cardiomyopathy is associated with a significantly reduced ejection fraction, often below 30% in severe cases, due to impaired ventricular contraction.
Which type of cardiomyopathy is most commonly associated with markedly increased left ventricular wall thickness?
A) Restrictive cardiomyopathy
B) Hypertrophic cardiomyopathy
C) Dilated cardiomyopathy
D) None of the above
Answer:
B) Hypertrophic cardiomyopathy
Rationale: Hypertrophic cardiomyopathy is characterized by significant thickening of the left ventricular wall, often due to genetic mutations affecting sarcomere proteins.
Which cardiomyopathy subtype commonly presents with conduction disease, particularly in amyloidosis, but rarely with ventricular arrhythmias?
A) Dilated cardiomyopathy
B) Restrictive cardiomyopathy
C) Hypertrophic cardiomyopathy
D) None of the above
Answer:
B) Restrictive cardiomyopathy
Rationale: Conduction abnormalities are common in restrictive cardiomyopathy, particularly in conditions such as amyloidosis, whereas ventricular arrhythmias are uncommon.
Which cardiomyopathy subtype is often associated with exertional intolerance and can also present with chest pain?
A) Dilated cardiomyopathy
B) Restrictive cardiomyopathy
C) Hypertrophic cardiomyopathy
D) All of the above
Answer:
C) Hypertrophic cardiomyopathy
Rationale: Exertional intolerance is common across all three types, but hypertrophic cardiomyopathy is notably associated with chest pain, likely due to increased myocardial oxygen demand and microvascular dysfunction.
Which form of cardiomyopathy is most likely to present with right-sided congestion symptoms early in the disease course?
A) Dilated cardiomyopathy
B) Restrictive cardiomyopathy
C) Hypertrophic cardiomyopathy
D) None of the above
Answer:
B) Restrictive cardiomyopathy
Rationale: Restrictive cardiomyopathy frequently leads to early right-sided congestion symptoms due to impaired ventricular filling and increased atrial pressures.
Which of the following is the most common infectious cause of myocarditis?
A) Bacteria
B) Fungi
C) Viruses
D) Parasites
Answer:
C) Viruses
Rationale: Myocarditis has been reported with various infective agents, but it is most commonly associated with viruses and the protozoan Trypanosoma cruzi.
Which receptor on cardiac myocytes is particularly involved in viral myocarditis caused by coxsackieviruses and adenoviruses?
A) β-adrenergic receptor
B) Toll-like receptor
C) Coxsackie-adenovirus receptor
D) NMDA receptor
Answer:
C) Coxsackie-adenovirus receptor
Rationale: These viruses enter cells via the coxsackie-adenovirus receptor, which is prominently located around intercalated disks and the AV node.
What is the role of Toll-like receptors in viral myocarditis?
A) They directly degrade viral proteins.
B) They recognize common antigenic patterns and trigger an immune response.
C) They prevent viral replication within the myocardium.
D) They induce viral latency within cardiac myocytes.
Answer:
B) They recognize common antigenic patterns and trigger an immune response.
Rationale: Toll-like receptors are crucial in recognizing viral components and initiating an innate immune response, which is essential in the early phase of myocarditis.
What is a potential long-term consequence of ongoing cytokine release and immune activation in myocarditis?
A) Increased viral replication and clearance of infection
B) Myocyte hypertrophy without structural remodeling
C) Disruption of collagen and elastin scaffolding, leading to ventricular dilation
D) Increased cardiac contractility and resistance to infection
Answer:
C) Disruption of collagen and elastin scaffolding, leading to ventricular dilation
Rationale: Ongoing cytokine release activates matrix metalloproteinases, which degrade collagen and elastin, contributing to ventricular dilation and heart failure.
During the direct viral invasion phase of myocarditis, viruses typically enter the body through which routes?
A) Respiratory and gastrointestinal tracts
B) Bloodstream and lymphatic system
C) Skin and mucous membranes
D) Nervous system and cerebrospinal fluid
Answer:
A) Respiratory and gastrointestinal tracts
Rationale: Viruses gain entry through the respiratory or gastrointestinal tract before infecting organs that express specific receptors, such as the coxsackie-adenovirus receptor in the heart.
Which of the following is a common initial presentation of viral myocarditis?
A) Progressive dyspnea and weakness after a viral illness
B) Sudden-onset hypertension and bradycardia
C) Isolated peripheral edema without respiratory symptoms
D) Chronic, asymptomatic cardiomegaly
Answer:
A) Progressive dyspnea and weakness after a viral illness
Rationale: Viral myocarditis often presents days to weeks after a viral syndrome, with progressive dyspnea, weakness, fever, and myalgias.
Which of the following electrocardiographic (ECG) findings may be seen in a patient with viral myocarditis?
A) Changes suggestive of pericarditis or acute myocardial infarction
B) Only sinus tachycardia with no other abnormalities
C) Atrioventricular dissociation without other conduction defects
D) A completely normal ECG in all cases
Answer:
A) Changes suggestive of pericarditis or acute myocardial infarction
Rationale: Myocarditis can present with ST-segment elevations, PR-segment depressions (like pericarditis), or mimic myocardial infarction.
Which of the following statements best describes fulminant myocarditis?
A) It progresses over months with gradual onset of dyspnea.
B) It is a slow-onset disease that does not require urgent intervention.
C) It rapidly progresses within hours to cardiogenic shock and multiple organ failure.
D) It is always caused by bacterial infections.
Answer:
C) It rapidly progresses within hours to cardiogenic shock and multiple organ failure.
Rationale: Fulminant myocarditis develops rapidly and can lead to cardiogenic shock, renal failure, hepatic failure, and coagulopathy, often requiring mechanical circulatory support.
What is the primary role of cardiac magnetic resonance imaging (MRI) in diagnosing myocarditis?
A) To assess coronary artery stenosis
B) To evaluate myocardial edema and gadolinium enhancement
C) To measure pulmonary artery pressures
D) To determine left atrial volume
Answer:
B) To evaluate myocardial edema and gadolinium enhancement
Rationale: MRI with T2-weighted imaging and gadolinium enhancement helps detect myocardial inflammation, distinguishing myocarditis from other cardiac conditions
When is an endomyocardial biopsy recommended in the evaluation of myocarditis?
A) In all cases of suspected viral myocarditis
B) When heart failure is accompanied by conduction blocks or ventricular arrhythmias
C) Only when cardiac MRI findings are inconclusive
D) Only when blood cultures confirm an infectious etiology
Answer:
B) When heart failure is accompanied by conduction blocks or ventricular arrhythmias
Rationale: Biopsy is indicated in cases where noninfectious inflammatory causes (e.g., sarcoidosis or giant cell myocarditis) are suspected, which may require immunosuppressive therapy.
What distinguishes definite myocarditis from probable myocarditis?
A) Presence of a viral syndrome with elevated cardiac biomarkers
B) Clinical symptoms of heart failure
C) Histologic or immunohistologic evidence of inflammation on biopsy
D) MRI findings suggestive of myocardial edema
Answer:
C) Histologic or immunohistologic evidence of inflammation on biopsy
Rationale: Definite myocarditis requires biopsy-proven inflammation, whereas probable myocarditis is diagnosed based on clinical presentation and imaging findings.
Which of the following best describes possible subclinical acute myocarditis?
A) Presence of cardiac symptoms along with abnormal ECG and biomarkers
B) No cardiac symptoms but with elevated cardiac biomarkers or abnormal ECG findings
C) Histologic or immunohistologic evidence of myocarditis
D) Presence of pericardial effusion without other findings
Answer:
B) No cardiac symptoms but with elevated cardiac biomarkers or abnormal ECG findings
Rationale: Possible subclinical acute myocarditis is diagnosed when a patient has a viral syndrome but no cardiac symptoms, yet shows biomarker elevation, abnormal ECG, or left ventricular dysfunction.
Which clinical feature differentiates probable acute myocarditis from possible subclinical acute myocarditis?
A) Presence of pericardial effusion
B) Histologic confirmation on biopsy
C) Presence of cardiac symptoms (e.g., chest pain, dyspnea)
D) MRI findings of myocardial fibrosis
Answer:
C) Presence of cardiac symptoms (e.g., chest pain, dyspnea)
Rationale: Probable acute myocarditis includes all features of possible myocarditis but also involves clinical symptoms such as dyspnea or chest pain.
What is the defining criterion for definite myocarditis?
A) Abnormal ECG and elevated cardiac biomarkers
B) Positive cardiac MRI findings
C) Histologic or immunohistologic evidence of myocardial inflammation on biopsy
D) Clinical symptoms of heart failure
Answer:
C) Histologic or immunohistologic evidence of myocardial inflammation on biopsy
Rationale: Definite myocarditis requires biopsy-confirmed inflammation, whereas probable myocarditis relies on clinical and imaging findings.
A patient presents with chest pain and shortness of breath after a recent viral illness. ECG shows ST-segment changes, and troponin is elevated. What is the most appropriate classification?
A) Possible subclinical acute myocarditis
B) Probable acute myocarditis
C) Definite myocarditis
D) Chronic myocarditis
Answer:
B) Probable acute myocarditis
Rationale: The presence of cardiac symptoms (chest pain, dyspnea) alongside ECG and biomarker abnormalities meets the criteria for probable acute myocarditis.
When does Peripartum Cardiomyopathy (PPCM) typically develop?
A) During the first trimester of pregnancy
B) Only after delivery
C) During the last trimester or within the first 6 months postpartum
D) At any point before conception
Answer:
✅ C) During the last trimester or within the first 6 months postpartum
Rationale: PPCM occurs late in pregnancy or after delivery, making it distinct from other pregnancy-related heart conditions. It is not diagnosed before the last trimester.
Which of the following is NOT a known risk factor for PPCM?
A) Twin pregnancy
B) Increased maternal age
C) Gestational diabetes
D) Preeclampsia
Answer:
✅ C) Gestational diabetes
Rationale: While preeclampsia, multiple pregnancies, older maternal age, and high parity are known risk factors, gestational diabetes is not directly associated with PPCM.
Which of the following therapies is currently being investigated for PPCM based on its proposed mechanisms?
A) Bromocriptine
B) Aspirin
C) Statins
D) Beta-blockers only
Answer:
✅ A) Bromocriptine
Rationale: Bromocriptine inhibits prolactin secretion, which has been implicated in PPCM pathogenesis. This therapy is still under investigation but shows potential for angiogenic balance restoration.
Which genetic mutation is found in about 15% of PPCM cases, suggesting a genetic link to dilated cardiomyopathy (DCM)?
A) MYH7
B) TTN
C) LMNA
D) DSP
Answer:
✅ B) TTN
Rationale: Truncating mutations in TTN (Titin gene) are seen in familial and sporadic DCM and have also been found in PPCM cases, suggesting a genetic predisposition in some patients.
Which cardiotoxicity caused by chemotherapy is often reversible?
A) Anthracycline-induced cardiotoxicity
B) Trastuzumab-induced cardiomyopathy
C) Cyclophosphamide-induced heart failure
D) Cisplatin-induced coronary spasm
Answer: B) Trastuzumab-induced cardiomyopathy
Rationale: Trastuzumab cardiomyopathy is often reversible, though about one-third of cases may persist and progress to heart failure.
What is the most common toxin implicated in chronic dilated cardiomyopathy (DCM)?
A) Cocaine
B) Alcohol
C) Amphetamines
D) Lead
Answer: B) Alcohol
Rationale: Chronic alcohol consumption is the most common toxin associated with DCM, contributing to more than 10% of heart failure cases. Alcoholic cardiomyopathy is linked to both direct toxic effects and metabolic alterations.
What is the estimated amount of alcohol intake necessary to cause cardiomyopathy?
A) 2 ounces of pure ethanol daily for 1–2 years
B) 4–5 ounces of pure ethanol daily for 5–10 years
C) 10 ounces of pure ethanol daily for 20 years
D) 1 ounce of pure ethanol weekly for life
Answer: B) 4–5 ounces of pure ethanol daily for 5–10 years
Rationale: Alcoholic cardiomyopathy has been associated with an intake of 80–100 g of pure ethanol daily for 5–10 years, equivalent to 1 liter of wine, 8 beers, or ½ pint of hard liquor.
Which chemotherapy agent is known for causing characteristic histologic changes such as vacuolar degeneration and myofibrillar loss in the heart?
A) Trastuzumab
B) Cyclophosphamide
C) Doxorubicin
D) 5-Fluorouracil
Answer: C) Doxorubicin
Rationale: Doxorubicin, an anthracycline, is associated with cardiotoxicity due to reactive oxygen species, mitochondrial damage, and inhibition of topoisomerase II, leading to vacuolar degeneration and myofibrillar loss.
Which of the following chemotherapy agents is most likely to cause acute coronary vasospasm leading to depressed cardiac contractility?
A) 5-Fluorouracil
B) Anthracyclines
C) Trastuzumab
D) Tyrosine kinase inhibitors
Answer: A) 5-Fluorouracil
Rationale: 5-Fluorouracil and cisplatin can cause recurrent coronary vasospasm, which may lead to myocardial ischemia and contractility dysfunction.
Which of the following best describes the cardiovascular side effects of VEGF inhibitors?
A) Coronary vasospasm
B) Myocardial fibrosis
C) Increased blood pressure and proteinuria
D) Direct myocardial toxicity leading to necrosis
Answer: C) Increased blood pressure and proteinuria
Rationale: VEGF inhibitors disrupt the balance between vasodilators and vasoconstrictors, leading to hypertension and proteinuria, similar to preeclampsia.
Which of the following is a hallmark of anthracycline-induced cardiotoxicity?
A) Large left ventricular dilation
B) Myocardial necrosis
C) Stroke volume reduction with modest ejection fraction decrease
D) Coronary artery thrombosis
Answer: C) Stroke volume reduction with modest ejection fraction decrease
Rationale: Anthracycline cardiotoxicity leads to reduced systemic perfusion with only a modest drop in ejection fraction, rather than significant left ventricular dilation.
Which of the following drugs is more cardiotoxic when used to treat multiple myeloma?
A) Bortezomib
B) Carfilzomib
C) Thalidomide
D) Lenalidomide
Answer: B) Carfilzomib
Rationale: Carfilzomib is more cardiotoxic than bortezomib and is associated with hypertension, ischemic events, thromboembolism, and heart failure.
What is another name for Takotsubo cardiomyopathy?
A) Ischemic heart disease
B) Apical ballooning syndrome
C) Restrictive cardiomyopathy
D) Hypertrophic cardiomyopathy
Answer: B) Apical ballooning syndrome
Rationale: Takotsubo cardiomyopathy is also known as apical ballooning syndrome because the left ventricle takes on a balloon-like shape due to basal contraction with apical dilation.
Takotsubo cardiomyopathy is most commonly seen in which patient population?
A) Young men after strenuous exercise
B) Older women after emotional or physical stress
C) Patients with congenital heart disease
D) Patients with uncontrolled hypertension
Answer: B) Older women after emotional or physical stress
Rationale: The condition primarily affects older women following sudden emotional or physical stress, leading to transient left ventricular dysfunction.
What imaging technique is most useful in distinguishing Takotsubo cardiomyopathy from an acute myocardial infarction?
A) Coronary angiography
B) Chest X-ray
C) Pulmonary function test
D) Cardiac PET scan
Answer: A) Coronary angiography
Rationale: Coronary angiography is often performed to rule out acute coronary occlusion, as Takotsubo cardiomyopathy mimics acute myocardial infarction but does not involve coronary blockage.
Which of the following best describes the pathophysiology of Takotsubo cardiomyopathy?
A) Coronary artery thrombosis
B) Intense sympathetic activation leading to catecholamine toxicity
C) Autoimmune destruction of myocardial cells
D) Chronic ischemic injury leading to fibrosis
Answer: B) Intense sympathetic activation leading to catecholamine toxicity
Rationale: The acute cardiomyopathy is believed to result from intense sympathetic activation, which may cause microvascular spasm and direct catecholamine-induced myocardial toxicity.
Which of the following findings on cardiac MRI is characteristic of Takotsubo cardiomyopathy?
A) Diffuse myocardial edema without necrosis
B) Patchy late gadolinium enhancement
C) Large areas of myocardial infarction
D) Myocardial fibrosis
Answer: A) Diffuse myocardial edema without necrosis
Rationale: Cardiac MRI in Takotsubo cardiomyopathy typically shows diffuse myocardial edema without necrosis, distinguishing it from myocardial infarction.
What is the primary pathophysiologic abnormality in restrictive cardiomyopathy?
A) Impaired systolic function
B) Impaired diastolic function
C) Increased cardiac output
D) Severe left ventricular hypertrophy
Answer: B) Impaired diastolic function
Rationale: Restrictive cardiomyopathy is primarily a diastolic dysfunction disorder where the ventricles are stiff and cannot fill properly. Systolic function is often mildly reduced but remains preserved until late stages.
Which of the following is a common echocardiographic finding in restrictive cardiomyopathy?
A) Massive left ventricular hypertrophy
B) Normal-sized ventricles with enlarged atria
C) Severe left ventricular dilation
D) Marked right ventricular hypertrophy
Answer: B) Normal-sized ventricles with enlarged atria
Rationale: In RCM, the ventricles remain normal or slightly enlarged, but both atria are significantly dilated due to chronic elevation in filling pressures.
Which of the following is a common early symptom of restrictive cardiomyopathy?
A) Sudden cardiac death
B) Severe angina
C) Subtle exercise intolerance
D) Severe syncope episodes
Answer: C) Subtle exercise intolerance
Rationale: Exercise intolerance is often the first symptom in RCM due to impaired diastolic filling and elevated ventricular pressures, but it may go unnoticed until congestive symptoms develop.
Which of the following is the most common cause of restrictive cardiomyopathy?
A) Sarcoidosis
B) Hemochromatosis
C) Amyloidosis
D) Endomyocardial fibrosis
Answer: C) Amyloidosis
Rationale: Amyloidosis is the most common cause of restrictive cardiomyopathy (RCM), characterized by amyloid fibril deposition leading to stiff ventricular walls and diastolic dysfunction.
In cardiac amyloidosis, what is the most common type of amyloid fibril deposition?
A) Beta-2 microglobulin
B) Immunoglobulin light chains (AL)
C) Serum amyloid A protein
D) Transthyretin (ATTR)
Answer: B) Immunoglobulin light chains (AL)
Rationale: The most common type of cardiac amyloidosis is AL amyloidosis, caused by monoclonal plasma cells producing abnormal immunoglobulin light chains. ATTR amyloidosis (transthyretin) is the second most common.
Which of the following findings is a key diagnostic clue for cardiac amyloidosis?
A) Severe left ventricular hypertrophy with high QRS voltage
B) Thickened ventricular walls with low QRS voltage on ECG
C) Dilated ventricles with globally reduced ejection fraction
D) Normal wall thickness with systolic anterior motion of the mitral valve
Answer: B) Thickened ventricular walls with low QRS voltage on ECG
Rationale: Thickened myocardium with disproportionately low ECG voltage is a hallmark of cardiac amyloidosis. The mismatch between wall thickness and ECG voltage is more common in AL amyloidosis than in ATTR amyloidosis.
Which of the following is a characteristic cardiac MRI finding in amyloidosis?
A) Apical hypertrophy
B) Patchy gadolinium enhancement
C) Diffuse late gadolinium enhancement
D) Midwall fibrosis
Answer: C) Diffuse late gadolinium enhancement
Rationale: Cardiac MRI in amyloidosis shows diffuse late gadolinium enhancement, reflecting widespread amyloid infiltration of the myocardium.
What is the typical prognosis of untreated AL amyloidosis with cardiac involvement?
A) Median survival of 6–12 months
B) Slow progression over decades
C) No impact on overall survival
D) Similar prognosis to hypertrophic cardiomyopathy
Answer: A) Median survival of 6–12 months
Rationale: AL amyloidosis with cardiac involvement has a poor prognosis, with a median survival of 6–12 months if untreated. New therapies like bortezomib have significantly improved survival.
Which treatment has been shown to improve survival in AL amyloidosis?
A) Tafamidis
B) Inotersen
C) Bortezomib
D) Beta-blockers
Answer: C) Bortezomib
Rationale: Bortezomib (a proteasome inhibitor) has significantly improved survival in AL amyloidosis by reducing plasma cell production of amyloidogenic light chains.
What is the first-line pharmacologic treatment for left ventricular outflow tract (LVOT) obstruction in hypertrophic cardiomyopathy?
a) Digoxin
b) β-Adrenergic blockers (e.g., metoprolol)
c) Loop diuretics
d) ACE inhibitors
Answer: b) β-Adrenergic blockers (e.g., metoprolol)
Rationale: Beta-blockers reduce heart rate, improve diastolic filling, and decrease myocardial contractility, which helps alleviate LVOT obstruction in hypertrophic cardiomyopathy.
If a patient with hypertrophic cardiomyopathy continues to have symptoms despite beta-blocker therapy, which medication can be added?
a) Digoxin
b) Disopyramide
c) Dobutamine
d) Nitrates
Answer: b) Disopyramide
Rationale: Disopyramide is a negative inotropic agent that reduces LVOT obstruction by decreasing myocardial contractility. It is useful for persistent symptoms of exertional dyspnea or chest pain.
Which of the following drugs should be avoided in hypertrophic cardiomyopathy due to worsening of outflow tract obstruction?
a) Verapamil
b) Amiodarone
c) Digoxin
d) Metoprolol
Answer: c) Digoxin
Rationale: Digoxin increases contractility, which can worsen LVOT obstruction. It should be avoided in hypertrophic cardiomyopathy.
Which invasive procedure is considered the gold standard for treating severe, medically refractory LVOT obstruction?
a) Mitral valve replacement
b) Alcohol septal ablation
c) Coronary artery bypass grafting
d) Surgical septal myectomy
Answer: d) Surgical septal myectomy
Rationale: Surgical myectomy, which removes a portion of the hypertrophied septum, is the gold standard for relieving LVOT obstruction in patients with severe symptoms refractory to medical therapy.
In patients with hypertrophic cardiomyopathy who are not candidates for surgery, which alternative procedure can be performed?
a) Alcohol septal ablation
b) Mitral valve repair
c) Pericardiocentesis
d) Pacemaker implantation
Answer: a) Alcohol septal ablation
Rationale: Alcohol septal ablation induces a controlled infarction of the proximal septum, reducing LVOT obstruction in patients who are not candidates for surgery.
What is the most common complication following both septal myectomy and alcohol septal ablation?
a) Mitral stenosis
b) Complete heart block
c) Ventricular rupture
d) Pericardial effusion
Answer: b) Complete heart block
Rationale: Both procedures can damage the conduction system, leading to complete heart block, which may require permanent pacemaker placement.
The primary mechanism of sudden cardiac death in hypertrophic cardiomyopathy is:
a) Pulmonary embolism
b) Atrial fibrillation
c) Ventricular tachyarrhythmias
d) Cardiac tamponade
Answer: c) Ventricular tachyarrhythmias
Rationale: Sudden cardiac death in hypertrophic cardiomyopathy is usually caused by ventricular tachyarrhythmias, including ventricular fibrillation.
Which of the following is considered the most effective strategy to prevent sudden cardiac death in high-risk hypertrophic cardiomyopathy patients?
a) Beta-blockers
b) Surgical myectomy
c) Implantable cardioverter-defibrillator (ICD)
d) Antiarrhythmic medications
Answer: c) Implantable cardioverter-defibrillator (ICD)
Rationale: ICDs are the most effective intervention for preventing sudden cardiac death in high-risk patients, as no medical or procedural intervention has been shown to reduce SCD risk.
Which arrhythmia is common in hypertrophic cardiomyopathy and increases stroke risk?
a) Atrial fibrillation
b) Atrioventricular block
c) Ventricular bigeminy
d) Sinus bradycardia
Answer: a) Atrial fibrillation
Rationale: Atrial fibrillation is common in hypertrophic cardiomyopathy and can lead to stroke due to thromboembolism.
Which activity is not recommended for patients with hypertrophic cardiomyopathy?
a) Walking
b) Competitive sports
c) Mild resistance training
d) Yoga
Answer: b) Competitive sports
Rationale: Patients with hypertrophic cardiomyopathy are at increased risk of sudden cardiac death, particularly with vigorous exercise or competitive sports.
