Cardiac Pharmacology

Cardiac Pharmacology

Justin M. Horner

Nathaniel W. Taggart

Philip L. Wackel


1. An 11-year-old female is admitted to the hospital after cardiac arrest from which she was successfully defibrillated. Her baseline electrocardiogram (ECG) from 1 month earlier when she was not on any medication is shown in Figure 14.1. Later that evening she develops recurrent nonsustained polymorphic ventricular tachycardia. Which of the following intravenous medications may be useful in treating this patient’s dysrhythmia?

A. Procainamide

B. Magnesium sulfate

C. Sotalol

D. Quinidine

E. Dofetilide

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1. (B) Prolonged QT interval is noted on the given ECG. The patient likely has long QT syndrome (LQTS) in the clinical scenario.

Management with intravenous magnesium sulfate is reasonable for patients who present with LQTS and few episodes of torsades de pointes. Magnesium is unlikely to be effective in patients with a normal QT interval. The other agents in the scenario tend to prolong the QT interval and therefore are not recommended.

2. An 8-year-old male is diagnosed with long QT syndrome (LQTS) associated with a mutation in sodium channel gene SCN5A following an evaluation for unexplained syncope. His baseline QTc interval is 490 msec. He undergoes placement of an ICD/pacemaker. While in the ICU, he has frequent episodes of nonsustained polymorphic ventricular tachycardia, which are suppressed by intravenous lidocaine administration. Which of the following oral medications would be the best outpatient treatment for this patient?

A. Quinidine

B. Sotalol

C. Dofetilide

D. Procainamide

E. Mexiletine

View Answer

2. (E) The patient in this scenario likely has type 3 long QT syndrome (LQT3).

Class IIb recommendation: Intravenous lidocaine or oral mexiletine may be considered in patients who present with LQT3 and torsades de pointes. The other agents in the given scenario tend to prolong QT interval and therefore are not recommended.

3. An 18-year-old man with a bileaflet aortic valve mechanical prosthesis that was placed 2 years ago is scheduled for an elective open urologic operation. He has no previous history of clots, arrhythmia, stroke, or transient ischemic attacks. On a recent echocardiogram, his left ventricular ejection fraction was 55%. Which of the following statements is most consistent with the 2020 recommendations from the American College of Cardiology for perioperative anticoagulation in this setting?

A. Warfarin should be stopped 3 days prior to the procedure, and he should be bridged with unfractionated heparin

B. Warfarin should be stopped 3 days prior to the procedure, and he should be bridged with subcutaneous heparin

C. Warfarin should be stopped 3 days prior to the procedure, and he should be started on clopidogrel

D. Warfarin should be stopped 3 days prior to the procedure, and no heparin bridging is necessary

E. Warfarin should be stopped 3 days prior to the procedure, and he should be bridged with a direct factor Xa inhibitor such as rivaroxaban

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3. (D) In the given scenario, the patient has a bileaflet mechanical aortic valve without any additional risk factors for thromboembolism (see below). The recommendation as per the ACC/AHA 2020 guidelines is to stop warfarin 3 to 4 days prior to the procedure without any need for heparin bridging. Class 1 recommendations for perioperative anticoagulation strategy as per ACC/AHA 2020 guidelines are quoted below.

Class 1 recommendation:

1. For patients with mechanical heart valves who are undergoing minor procedures (e.g., dental extractions or cataract removal) where bleeding is easily controlled, continuation of VKA anticoagulation with a therapeutic INR is recommended.

2. For patients with a bileaflet mechanical AVR and no other risk factors for thromboembolism who are undergoing invasive procedures, temporary interruption of VKA anticoagulation, without bridging agents while the INR is subtherapeutic, is recommended.

*Risk factors: atrial fibrillation, previous thromboembolism, LV systolic dysfunction, hypercoagulable conditions, older-generation thrombogenic valves (ball-cage or tilting disc), or more than one mechanical valve.

4. A 16-year-old male with a previously repaired partial AV canal defect and cleft mitral valve undergoes mechanical bileaflet mitral valve prosthesis placement for symptomatic severe mitral valve regurgitation. His discharge echocardiogram shows a left ventricular ejection fraction of 60%. He has no history of thromboembolic events or thrombophilia. Based on the 2020 American College of Cardiology recommendations for postoperative anticoagulation, which of the following anticoagulation strategies is recommended for this patient?

A. Warfarin only (goal INR of 2.5)

B. Warfarin only (goal INR of 3.0)

C. Warfarin only (goal INR of 3.5)

D. Warfarin (goal INR of 3.0) and aspirin 325 mg

E. Warfarin (goal INR of 2.5) and aspirin 325 mg

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4. (B) Please refer to class 1 recommendations from ACC/AHA 2020 guidelines quoted below for postoperative anticoagulation management following mechanical valve placement and the class 2b recommendation on the concomitant use of aspirin therapy.

Class 1 recommendations:

1. In patients with a mechanical prosthetic valve, anticoagulation with a VKA is recommended.

2. For patients with a mechanical bileaflet or current-generation single-tilting disc AVR and no risk factors for thromboembolism, anticoagulation with a VKA to achieve an INR of 2.5 is recommended.

3. For patients with a mechanical AVR and additional risk factors for thromboembolism (e.g., AF, previous thromboembolism, LV dysfunction, hypercoagulable state) or an older-generation prosthesis (e.g., ball-in-cage), anticoagulation with a VKA is indicated to achieve an INR of 3.0.

4. For patients with a mechanical mitral valve replacement, anticoagulation with a VKA is indicated to achieve an INR of 3.0.

Class 2b recommendation:

1. For patients with a mechanical surgical aortic valve replacement or mitral valve replacement who are managed with a VKA and have an indication for antiplatelet therapy, addition of aspirin 75 to 100 mg daily may be considered when the risk of bleeding is low.

5. An 18-year-old woman with a history of parachute mitral valve and mechanical mitral prosthesis placement takes warfarin 4 mg/d. She has just learned that she is 14 weeks pregnant and wishes to continue with her pregnancy. Which of the following treatment options would you advise?

A. Strongly recommend elective termination of the pregnancy

B. Discontinue warfarin for the remainder of the pregnancy, then restart in the postpartum period

C. Continue warfarin for the remainder of the pregnancy and through delivery

D. Discontinue warfarin now and restart at 25 to 30 weeks gestation, treating with subcutaneous heparin in the interim

E. Continue warfarin until 1 week prior to planned delivery, then treat with continuous intravenous heparin or LMWH

View Answer

5. (E) Anticoagulation with frequent monitoring needs to be continued through pregnancy in the setting of a mechanical valve and only stopped prior to delivery. The class 1 recommendations from the ACC/AHA 2020 guidelines are quoted below.

Class 1 recommendations:

1. Pregnant women with mechanical prostheses should receive therapeutic anticoagulation with frequent monitoring during pregnancy.

2. Women with mechanical heart valves who cannot maintain therapeutic anticoagulation with frequent monitoring should be counseled against pregnancy.

3. Women with mechanical heart valves and their providers should use shared decision-making to choose an anticoagulation strategy for pregnancy. Women should be informed that VKA during pregnancy is associated with the lowest likelihood of maternal complications but the highest likelihood of miscarriage, fetal death, and congenital abnormalities, particularly if taken during the first trimester and if the warfarin dose exceeds 5 mg/d.

4. Pregnant women with mechanical valve prostheses who are on warfarin should switch to twice-daily LMWH (with a target anti-Xa level of 0.8 to 1.2 U/mL at 4 to 6 hours after dose) or intravenous UFH (with an activated partial thromboplastin time [aPTT] 2 times control) at least 1 week before planned delivery.

5. Pregnant women with mechanical valve prostheses who are on LMWH should switch to UFH (with an aPTT 2 times control) at least 36 hours before planned delivery.

6. Pregnant women with valve prostheses should stop UFH at least 6 hours before planned vaginal delivery.

7. If labor begins or urgent delivery is required in a woman therapeutically anticoagulated with a VKA, cesarean section should be performed after reversal of anticoagulation.

6. A 9-year-old patient with myocarditis, cardiomegaly, and reduced left ventricular systolic function develops a dry cough without other respiratory symptoms after starting oral heart failure therapy. Which of the following is the most likely mechanism of cough?

A. Increased bradykinin

B. Inhibition of Na+-K+ ATPase pump

C. Inhibition of calcium entry into vascular smooth muscle cells

D. Inhibition of activation of angiotensin II receptors

E. Increased production of angiotensin II

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6. (A) The patient was started on ACE inhibitor (captopril, enalapril, etc.). ACE converts angiotensin I to angiotensin II. It also inactivates or breaks down bradykinin. ACE inhibitors therefore increase bradykinin levels and decrease angiotensin II levels. Increased bradykinin levels are thought to be responsible for dry cough symptoms in patients taking ACE inhibitors. Digoxin inhibits Na+-K+ ATPase pump. CCBs inhibit calcium entry into vascular smooth muscle cells. Angiotensin II receptor blockers (ARBs) inhibit the activation of angiotensin II receptors. Dry cough is not commonly recognized as a side effect of digoxin, CCBs, or ARBs.

7. A 7-year-old well child with a recent history of palpitations is admitted to the ED with shortness of breath and tachyarrhythmia. He has no previous history of syncope or exercise-induced symptoms. His ECG is shown in Figure 14.2. Vagal maneuvers have failed. His blood pressure (BP) is 100/60 mm Hg. The patient has undergone electrical cardioversion three times, with transient return to sinus rhythm, after which the tachycardia recurs. Which of the following medications would be most likely to treat this patient’s arrhythmia?

A. IV adenosine

B. IV digitalis

C. IV amiodarone

D. IV β-blocker

E. IV diltiazem

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7. (C) In the given scenario, atrial fibrillation with preexcitation is the diagnosis. This is the most likely rhythm with an irregularly irregular wide complex tachycardia in an otherwise healthy patient. In atrial fibrillation with preexcitation, antegrade conduction would be through both the AV node and accessory pathway, and some beats are likely to be fusion beats. Any AV nodal blocking agent (adenosine, digitalis, diltiazem, β-blocker) is likely to result in unopposed ventricular activation through accessory pathway and can result in ventricular fibrillation. Thus, AV nodal blocking agents are best avoided in this scenario. Direct current cardioversion is the treatment of choice. If this is not possible, amiodarone may be given in this situation as it can restore atrial fibrillation to sinus rhythm as well as decrease accessory pathway conduction. Amiodarone is a class III antiarrhythmic agent that slows cardiac conduction (including accessory pathway conduction).

8. A 10-month-old female infant presents 1 week after hospital discharge following repair of tetralogy of Fallot (TOF). Her parents describe a 3-day history of vomiting without diarrhea. She has not had a fever. Cardiac monitoring reveals the rhythm shown in Figure 14.3.

Which of the following medications is most likely to cause this patient’s symptoms and electrocardiographic findings?

A. Digoxin

B. Propranolol

C. Furosemide

D. Amiodarone

E. Chlorothiazide

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8. (A) The ECG shows sinus rhythm with varying degrees of AV block (predominately 2:1 AV block with occasional Mobitz type 1 second-degree AV block (i.e., Wenckebach). Accelerated junctional rhythm is also seen in the first part of the tracing. Of the medications given above, digoxin is the most likely culprit to produce nausea/vomiting and high-grade AV block with activation of ectopic pacemakers (junctional, ventricular, etc.).

9. A 13-year-old male with a history of catecholaminergic polymorphic ventricular tachycardia (CPVT) is admitted to the ICU after an episode of syncope with exertion. In the ICU, he is noted to have frequent episodes of polymorphic ventricular tachycardia associated with hypotension. Which of the following is the best first-line antiarrhythmic therapy for this child?

A. Amiodarone

B. Lidocaine

C. β-Blocker

D. Calcium channel blocker (CCB)

E. Digoxin

View Answer

9. (C) In CPVT patients with VT/VF storm, intravenous β-blocker therapy is considered the first line of treatment. General anesthesia can be used as a last resort if β-blocker therapy is ineffective.

10. A 13-month-old male infant referred to you for a heart murmur is diagnosed with a secundum atrial septal defect (ASD) measuring 6 mm. He was born at 38 weeks of gestation and has been thriving well without any symptoms. There is mild right heart enlargement on echocardiogram, and right ventricular systolic pressure is estimated to be 30 mm Hg. His mother is concerned about RSV and wants to know whether her son needs any palivizumab prophylaxis for the RSV season. Which of the following is the most appropriate answer?

A. RSV prophylaxis is not indicated, because he is over 1 year old

B. RSV prophylaxis is recommended for him until he is 2 years old

C. His heart disease does not qualify him for RSV prophylaxis

D. RSV prophylaxis would only be recommended if he had a prior history of RSV infection

E. RSV prophylaxis would be recommended for him if he were exposed to cigarette smoke at home

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10. (C) Since he does not have hemodynamically significant ASD, patient is unlikely to benefit from RSV prophylaxis. He does not meet other criteria for prophylaxis based on the 2014 AAP guidelines for palivizumab prophylaxis. According to the more recent AAP guidelines, children who are 12 months of age or younger with hemodynamically significant cyanotic and acyanotic congenital heart disease may benefit from palivizumab prophylaxis.

Children younger than 12 months of age with congenital heart disease who are most likely to benefit from immunoprophylaxis include:

  • infants with acyanotic heart disease who are being treated for congestive heart failure and who will require cardiac surgical procedures

  • infants with moderate to severe pulmonary hypertension

The new guidelines do not provide specific recommendations for infants with palliated or unrepaired cyanotic heart disease. [Pediatrics. 2014;134(2):415-420]

11. You are evaluating a 3-month-old female infant in the outpatient pediatric cardiology clinic. She was diagnosed with double-outlet right ventricle with normally related great arteries. She is receiving concentrated feedings (24 kcal/oz) and 1 mg/kg furosemide twice daily. She is growing well with mild tachypnea at rest. Her resting oxygen saturation is 94%. Surgery is scheduled in early December, one month away. Her mother wants to know whether palivizumab would be helpful during the current RSV season. Which of the following is the most appropriate response to her question?

A. Palivizumab prophylaxis has been shown to reduce the risk of RSV infection and is therefore beneficial

B. Palivizumab prophylaxis has been shown to reduce mortality rate from RSV in patients with congenital heart disease and therefore is recommended

C. Palivizumab would protect her from most viral infections including influenza A and B

D. Palivizumab would likely decrease her risk of hospitalization due to RSV and therefore is recommended

E. Palivizumab is not recommended in infants under 6 months of age

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11. (D) This patient is a candidate for RSV prophylaxis given the presence of acyanotic heart disease that requires therapy for congestive heart failure within the first year of life. The primary benefit of immunoprophylaxis with palivizumab is a decrease in the rate of RSV-associated hospitalization. Results from double-blinded, randomized, placebo-controlled trials with palivizumab involving 2,789 infants and children with prematurity, chronic lung disease, or congenital heart disease demonstrated a reduction in RSV hospitalization rates of 39% to 78% in different groups. None of the clinical trials have demonstrated a significant decrease in the rate of mortality attributable to RSV infection in infants who receive prophylaxis. [Pediatrics. 2014;134(2):415-420]

12. A 5-month-old female infant with dilated cardiomyopathy is started on furosemide. This medication acts by inhibiting which of the following ion channels?

A. Na+-2Cl-K+ cotransporter in the loop of Henle

B. Na+-Cl cotransporter in the proximal tubule

C. Na+-K+ATPase pump in the distal tubule

D. Na+-H+ cotransporter in the loop of Henle

E. Na+-Ca2+ cotransporter in the proximal tubule

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12. (A) Furosemide inhibits Na+-2Cl-K+ cotransporter in the loop of Henle and is therefore termed a loop diuretic. Thiazide diuretics inhibit Na+-Cl cotransporter. Digoxin inhibits Na+-K+ ATPase pump.

13. A 17-year-old previously healthy female presents to the ED with a 2-day history of chest pain. Her ECG shows diffuse ST-segment elevation and PR-segment depression suggestive of pericarditis. Echocardiogram shows normal biventricular size and function with a small pericardial effusion. There is no history of recent fever, rash, sore throat, or joint pains. Which of the following is the best treatment option for this patient?

A. Aspirin 325 mg four times/d for 4 weeks

B. Prednisone 1 mg/kg/d followed by tapering after 2 weeks once the patient is asymptomatic

C. Colchicine therapy for 4 to 6 days

D. Ibuprofen 600 to 800 mg three times a day for 7 to 10 days

E. Clopidogrel 75 mg daily for 2 weeks

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13. (D) The patient in the given scenario most likely has idiopathic/viral pericarditis. Ibuprofen and aspirin have been most commonly used and provide prompt relief of pain in most patients but they do not alter the natural history of the disease. High-dose aspirin (800 mg orally every 6 to 8 hours for 7 to 10 days followed by gradual tapering of the dose by 800 mg per week for three additional weeks) is usually recommended if aspirin is used. Although acute pericarditis appears to respond dramatically to corticosteroids, early use of corticosteroids has been associated with an increased risk of relapsing pericarditis in multiple studies.

Routine use of colchicine in the treatment of acute pericarditis has been supported by the Colchicine for Acute Pericarditis (COPE) trial that randomized patients into receiving aspirin alone versus aspirin + colchicine. A 4- to 6-week colchicine therapy may be considered in patients with acute pericarditis, especially in those who have not benefitted from NSAID therapy after 1 week. In this given scenario, ibuprofen is the best option given the side effect profile of colchicine, and it would also require a longer course than listed.

14. A 5-day-old neonate with hypoplastic left heart syndrome is being cared for in the cardiac ICU 2 days after a Norwood operation with right modified Blalock-Taussig shunt. Arterial blood gas (on FiO2 = 21%) shows a pH of 7.2. PO2 is 42 mm Hg, PCO2 is 45 mm Hg, SpO2 is 80%, and hemoglobin is 14 g/dL. Near-infrared spectroscopy (NIRS) probes consistently show saturations in the 40% range. ECG shows sinus tachycardia with a heart rate of 180 bpm. Arterial BP is 78/58 mm Hg. Chest x-ray shows no evidence of pulmonary congestion or significant infiltrates and lung fields are well expanded. The patient is on milrinone 0.4 mcg/kg/min and norepinephrine 1 mcg/kg/min. Urine output over the past 6 hours has averaged 1 cc/kg/hr. Limited bedside echo shows no significant pericardial effusion. The patient just received two 10 mL/kg boluses of normal saline. Which of the following interventions is most likely to benefit this patient?

A. IV furosemide

B. Decrease norepinephrine infusion rate

C. IV β-blocker therapy

D. Decrease milrinone infusion rate

E. Increasing the inspired FiO2 concentration

View Answer

14. (B) NIRS saturation is a good surrogate for tissue level saturation/oxygenation. NIRS saturation can be substituted for a mixed venous saturation (MVO2). The difference between SaO2 and MVO2 is a surrogate for cardiac output that is likely to be low given the difference of 40 (80 – 40) in this scenario, which would explain the pH of 7.2 (acidosis).

The pulmonary venous O2 can be assumed to be close to 100% given the FiO2 of 21% and clear lungs. The Qp/Qs in this scenario is 20.

Qp/Qs = (SaO2 – MVO2)/(pulmonary venous O2 – SaO2) = (80 – 40)/(100 – 80) = 40/20 = 2.

Thus, the patient has a low systemic cardiac output state and his lungs are getting at least two times the systemic blood flow. Norepinephrine is a potent vasoconstrictor. Weaning norepinephrine would lower systemic vascular resistance (SVR) and improve cardiac output, making the Qp/Qs more balanced. This should be the first line of management in addition to giving fluids that has already been tried in this patient. IV furosemide would decrease the intravascular volume and be detrimental for the patient. IV β-blocker therapy may decrease cardiac inotropy and worsen the low output state. Decreasing the milrinone would reduce the systemic cardiac output by increasing the SVR and by decreasing the cardiac inotropy. Increasing the FiO2 would lower the PVR and lead to more pulmonary blood flow at the expense of systemic blood flow (increase in Qp/Qs).

15. A 10-month-old infant is treated for Kawasaki disease (KD) with intravenous immunoglobulin (IVIG) and aspirin. Which of the following statements regarding use of steroids in KD is most accurate?

A. A 24-hour single dose of IV steroid may be considered in addition to IVIG as primary therapy

B. Oral steroids may be used instead of aspirin if the patient remains afebrile but shows persistent elevation of acute inflammatory markers (ESR, CRP)

C. Steroids are contraindicated in Kawasaki patients

D. IV steroids may be used instead of IVIG in an uncomplicated patient

E. IV steroids may be considered if the patient has persistent or recrudescent fever after initial treatment with ASA and at least one dose of IVIG

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15. (E) Initial therapy for KD during the acute phase is IVIG and high-dose aspirin. Single-dose pulse methylprednisolone should not be administered with IVIG as routine primary therapy for patients with KD. Administration of a longer course of corticosteroids (e.g., tapering over 2 to 3 weeks), together with IVIG 2 g/kg and ASA, may be considered for treatment of high-risk patients with acute KD, when such high risk can be identified in patients before initiation of treatment. In the case of persistence or recurrence of fever despite one dose of IVIG, it is reasonable to administer a second dose of IVIG (2 g/kg) to patients with persistent or recrudescent fever at least 36 hours after the end of the first IVIG infusion. Administration of high-dose pulse steroids (usually methylprednisolone 20 to 30 mg/kg intravenously for 3 days, with or without a subsequent course and taper of oral prednisone) may be considered as an alternative to a second infusion of IVIG or for retreatment of patients with KD who have had recurrent or recrudescent fever after additional IVIG. Administration of a longer (e.g., 2 to 3 weeks) tapering course of prednisolone or prednisone, together with IVIG 2 g/kg and ASA, may be considered in the retreatment of patients with KD who have had recurrent or recrudescent fever after initial IVIG treatment.

16. A 7-year-old female whose parents recently emigrated from Mexico is diagnosed with acute rheumatic fever (RF). She complains of mild chest pain, but no shortness of breath. Cardiac examination reveals normal S1 and S2, with a soft holosystolic murmur at the apex. Neck veins do not appear to be distended. Abdominal examination shows no organomegaly. Echocardiogram shows small pericardial effusion, mild to moderate mitral valve regurgitation, mild aortic valve regurgitation, mildly dilated left ventricle with an ejection fraction of 60%. Which of the following treatment regimens should be initiated in the above patient?

A. IV steroids

B. Oral steroids

C. High-dose aspirin

D. β-Blocker therapy

E. IVIG + aspirin

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16. (C) The patient has mild to moderate carditis that needs therapy with high-dose aspirin (80 to 100 mg/kg/d in four divided doses in children). Oral prednisone is indicated for more severe carditis associated with a sicker patient in the setting of heart failure, severe valvular regurgitation, significant pericarditis/myocarditis, or reduced cardiac function. There is no recommendation for combining oral steroids with aspirin for treatment of acute RF. IVIG + aspirin is used in the treatment of KD. There is no indication for a β-blocker in pericarditis.

17. Which of the following statements is true regarding immunosuppressive medications used in patients following heart transplantation?

A. Sirolimus is a calcineurin inhibitor

B. Tacrolimus is not available for intravenous use

C. Sirolimus acts by blocking gene transcription

D. Tacrolimus has been associated with improved survival over cyclosporine

E. Sirolimus is less nephrotoxic than cyclosporine

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17. (C) Sirolimus acts at a more distal site in the lymphocyte activation cascade by blocking transcription of activation genes. Sirolimus (also known as rapamycin) is not a calcineurin inhibitor. Cyclosporine and tacrolimus are calcineurin inhibitors. Cyclosporine and tacrolimus are available for intravenous use. Tacrolimus offers no survival advantage over cyclosporine in heart transplant recipients. Sirolimus may be less nephrotoxic over the long term.

18. A 7-year-old female who was appropriately treated for her first episode of rheumatic fever (RF) with mild carditis is followed up at 3 months, 6 months, and then at 1 year. Serial follow-up echocardiograms show no residual pericardial effusion, trivial mitral valve regurgitation, no aortic valve regurgitation, normal left ventricular chamber size, and function. She is maintained on RF antibiotic prophylaxis and continues to remain asymptomatic without any recurrence of streptococcal sore throat. If there is no echocardiographic evidence of worsening ventricular or valvular function, which of the following is the best recommendation for ongoing secondary antibiotic prophylaxis?

A. Antibiotic prophylaxis should be continued for 5 years

B. Antibiotic prophylaxis should be continued for 10 years

C. Antibiotic prophylaxis should be continued until she is 21 years of age

D. Antibiotic prophylaxis should be continued until she is 40 years of age

E. She will need lifelong antibiotic prophylaxis

View Answer

18. (C) The patient had mild carditis during RF but is free of residual heart disease now. Per guidelines, she will need RF antibiotic prophylaxis for at least 10 years or until 21 years of age, whichever is longer.

As per the current guidelines,

  • RF patients with carditis and residual heart disease (persistent valvular disease) should receive treatment for a duration of 10 years or until 40 years of age (whichever is longer, sometimes lifelong) after the last attack of RF.

  • RF patients with carditis but without residual heart disease (no valvular disease) should receive treatment for a duration of 10 years or until 21 years of age (whichever is longer) after the last attack of RF.

  • RF patients without carditis should receive treatment for a duration of 5 years or until 21 years of age (whichever is longer) after the last attack of RF.

19. According to the 2007 AHA/ACC guidelines, infective endocarditis (IE) prophylaxis is recommended in which of the following clinical scenarios?

A. A 7-year-old patient who has undergone cardiac transplantation 18 months ago with trivial tricuspid valve regurgitation prior to dental extraction

B. An 8-year-old patient who has undergone device closure of ASD 4 months ago with residual shunt at the site of prosthetic device who is scheduled to undergo an upper gastrointestinal endoscopy

C. A 9-year-old patient with TOF who underwent complete repair at 6 months of age and has an RV to PA conduit and is scheduled to have dental brace placement

D. An 8-year-old patient with prosthetic mitral valve with previous history of IE who is scheduled for an outpatient cystoscopy

E. A 12-year-old patient who has undergone percutaneous PDA closure 4 months ago who needs a root canal

View Answer

19. (E) Please refer to the guidelines as quoted below.

Class IIa recommendations:

Prophylaxis against IE is reasonable for the following patients at highest risk for adverse outcomes from IE who undergo dental procedures that involve manipulation of either gingival tissue or the periapical region of teeth or perforation of the oral mucosa:

  • Patients with prosthetic cardiac valves or prosthetic material used for cardiac valve repair

  • Patients with previous IE

  • Patients with CHD

    • Unrepaired cyanotic CHD, including palliative shunts and conduits

    • Completely repaired CHD repaired with prosthetic material or device, whether placed by surgery or by catheter intervention, during the first 6 months after the procedure

    • Repaired CHD with residual defects at the site or adjacent to the site of a prosthetic patch or prosthetic device (both of which inhibit endothelialization)

  • Cardiac transplant recipients with valve regurgitation due to a structurally abnormal valve

IE prophylaxis is not recommended for the following dental procedures: routine anesthetic injections through noninfected tissue, dental radiographs, placement/removal of orthodontic/prosthodontic appliances, shedding of deciduous teeth, and bleeding from trauma to lips/oral mucosa. IE prophylaxis is not recommended for the following respiratory procedures: bronchoscopy without biopsy, endotracheal intubation, or myringotomy with tube insertion. IE prophylaxis is not recommended for all gastrointestinal and genitourinary procedures including EGD and colonoscopy even with biopsy.

20. A 14-year-old male is referred to your clinic for management of elevated LDL cholesterol. Six and seven months ago his LDL level was 196 mg/dL and 190 mg/dL, respectively, and he was advised appropriate dietary intervention and weight reduction regimen. At present his LDL level is 202 mg/dL, HDL is 38 mg/dL, and triglycerides are 120 mg/dL. His BMI is 31 kg/m2 and his TSH level is normal. He has been compliant with his diet and exercise program and has lost 3 kg over the past year. He was adopted and therefore family history is not well known. Which of the following statements is most accurate?

A. Continued dietary intervention alone will likely significantly reduce his LDL level over the next 6 months

B. Oral statin therapy should be strongly considered

C. Oral niacin therapy is the best first-line option due to its side effect profile

D. Fibric acid derivatives should be considered

E. If drug therapy is considered, bile acid-binding resins would be the first-line therapy given their favorable safety and side effect profile

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20. (B) The child is ≥10 years old and meets criteria for pharmacologic lipid-lowering therapy per the 2011 AAP guidelines since his LDL remained ≥190 mg/dL after a 6-month trial of diet and exercise modifications. Statin therapy is considered the first-line LDL lowering agent. A bile acid sequestrant or cholesterol absorption inhibitor may be added as a second agent if statin therapy alone is insufficient in lowering the LDL.

21. A 16-year-old male recently diagnosed with hypertrophic cardiomyopathy (HCM) presents for evaluation. No other associated medical conditions are present. Medications include multivitamins. He is asymptomatic at rest but complains of shortness of breath with exertion. There is no history of syncope/presyncope or family history of HCM or sudden death. His resting HR is 80 bpm and BP is 130/80 mm Hg. His echocardiogram shows a septal thickness of 26 mm, ejection fraction = 70%, left ventricular outflow tract maximum instantaneous gradient 60 mm Hg. Cardiac MRI shows no late gadolinium enhancement. Recent Holter report showed frequent single PVCs, but no sustained tachycardia. On the basis of the above information, which of the following is the best initial treatment for this patient?

A. ICD placement

B. Digoxin

C. Furosemide

D. β-Blocker

E. Nifedipine

View Answer

21. (D) The traditional therapeutic medication for HCM is β-blocker. If CCBs are used, then preferred medications would be diltiazem and verapamil. Dihydropyridine CCBs like nifedipine would cause peripheral vasodilation and reflex tachycardia that are both detrimental in an HCM patient with obstruction. Furosemide by reducing preload and therefore left ventricular filling (through its diuretic effect) could worsen the degree of obstruction in an HCM patient. ICD is not indicated at present as the patient has no clearly established sudden death risk factors (i.e., personal history of cardiac arrest or sustained VT, LV wall thickness of ≥30 mm, family history of sudden death in a first-degree relative, or unexplained syncope).

22. Which of the following medications used in heart transplant recipients can inhibit smooth muscle proliferation and may have the advantage of inhibiting coronary allograft vasculopathy?

A. Methylprednisolone

B. Sirolimus

C. Antithymocyte globulin (ATG)

D. Cyclosporine

E. Tacrolimus

View Answer

22. (B) Sirolimus can inhibit smooth muscle proliferation and may have the advantage of inhibiting coronary vasculopathy. Sirolimus is not a calcineurin inhibitor and may be used in combination with, or in lieu of, calcineurin inhibitors. Sirolimus may be less nephrotoxic over the long term.

23. A 19-year-old male with d-transposition of the great arteries who is status post arterial switch operation as an infant is known to have LV systolic dysfunction and is currently taking carvedilol, enalapril, and digoxin. You are seeing him in the ICU after he was admitted overnight for treatment of ventricular tachycardia. He is no longer having VT, but on examination, he has tremors and slurred speech. Which of the following is the most likely treatment he received for ventricular tachycardia?

A. Esmolol

B. Amiodarone

C. Lidocaine

D. Adenosine

E. Digoxin

View Answer

23. (C) Lidocaine is considered a first-line agent in the acute treatment of ventricular tachycardia. It is a class Ib antiarrhythmic and is available IV. Lidocaine has a narrow therapeutic window and toxicity can occur at slightly higher levels. The most common side effects from lidocaine involve the central nervous system and include tremors, light-headedness, ataxia, dysarthria, mood/personality changes, hallucinations, and seizures. Lidocaine levels should be monitored, and dosing adjusted accordingly. Esmolol, verapamil, and amiodarone can be used in acute treatment of VT but generally do not have acute side effects of CNS toxicity. Adenosine effects on the AV node are short lived and except in very rare cases, adenosine has no role in the treatment of VT.

24. A 5-year-old female with idiopathic dilated cardiomyopathy undergoes induction with rabbit antithymocyte globulin (ATG) prior to orthotopic cardiac transplantation. Which of the following side effects of ATG is most common?

A. Fever

B. Rash

C. Abdominal pain

D. Hyperkalemia

E. Myalgia

View Answer

24. (A) All of the signs and symptoms listed can result from rabbit ATG infusion. The most common reported side effect is fever (over 60%). Other common side effects include rash (<25%), hyperkalemia (25% to 30%), abdominal pain (35% to 40%), myalgia (up to 40%), and shivering (55% to 60%).

25. A 15-year-old male presents to the ER with fast heart rate (HR) and some shortness of breath. His ECG shows a regular narrow QRS tachycardia (HR 235 bpm) without discernible P waves. He was discharged 24 hours ago from the hospital following management of asthma exacerbation and received treatment in the intensive care unit. Vagal maneuvers have failed to bring down his HR. Which of the following statements regarding adenosine is true?

A. Adenosine should be slowly pushed to avoid bronchospasm

B. If bronchospasm results, it will only last several seconds, then resolve

C. Patients who have undergone orthotopic heart transplant are less responsive to adenosine

D. Transient hypertension may result from adenosine administration

E. Flushing of the face is a common side effect

View Answer

25. (E) Both adenosine and β-blockers have the potential to exacerbate bronchospasm in this patient. Although the electrophysiologic effects of adenosine are temporary, the bronchospasm may persist for a long period of time. Heart transplant recipients are particularly sensitive to adenosine, and one-quarter to one-half the dose should be used initially as long periods of AV block may be noted with higher doses. Adenosine has a half-life of <2 seconds and is metabolized quickly in the blood. It therefore must be given as rapidly as possible in a large-bore IV as close to the heart as possible. Flushing and hypotension are common side effects. The bradycardia caused by adenosine may precipitate other arrhythmias including atrial fibrillation or ventricular tachycardia, so an external defibrillator should be readily available. The typical dose is 100 to 400 µg/kg in children.

26. A 13-year-old female is newly diagnosed with idiopathic pulmonary arterial hypertension. She experiences shortness of breath at rest and has severe right ventricular enlargement with severe dysfunction. She is started on IV treprostinil, oral sildenafil, and ambrisentan. Which of the following is the correct statement among the following regarding her pharmacologic treatment?

A. Ambrisentan is an endothelin A receptor agonist

B. Treprostinil is a prostaglandin (PGE2) analogue

C. Ambrisentan does not affect cytochrome P450 enzyme activity

D. Sildenafil is a phosphodiesterase 3 inhibitor

E. Epoprostenol would be favored over treprostinil due to its longer half-life

View Answer

26. (C) Combination therapy is increasingly used in children to treat severe pulmonary arterial hypertension despite the lack of published evidence. Ambrisentan is a selective endothelin A receptor antagonist. It does not induce or inhibit cytochrome P450 enzymes and is metabolized through glucuronidation. Therefore, it is much less hepatotoxic than bosentan. Treprostinil is a prostacyclin (PGI2) analogue and is not a prostaglandin (PGE2) analogue. It is favored over epoprostenol for long-term prostacyclin therapy due to its longer half-life. Sildenafil works through nitric oxide-cyclic GMP cascade, but it is a phosphodiesterase 5 inhibitor and not a phosphodiesterase 3 inhibitor. Milrinone is a phosphodiesterase 3 inhibitor.

27. A 16-year-old male is evaluated by his cardiologist following a recent episode of unexplained syncope. His resting ECG and echocardiogram are normal, and the history is not typical for vasovagal syncope. His father is an immigrant from Southeast Asia and was diagnosed with Brugada syndrome 1 year ago. Which of the following tests would be helpful in making a definitive diagnosis in this patient?

A. Epinephrine challenge test

B. Cardiac MRI

C. Isoproterenol provocative test

D. Provocative testing with procainamide

E. Exercise test

View Answer

27. (D) The ECG changes in Brugada syndrome can be dynamic and thus missed on a single ECG screening. Since the characteristic ECG hallmark may be concealed, drug challenge with sodium channel blockers (which may exacerbate the sodium channel dysfunction) to bring out the typical ECG changes has been proposed as a useful tool for the diagnosis of Brugada syndrome. Drugs employed for this purpose have included ajmaline, flecainide, procainamide, pilsicainide, disopyramide, and propafenone although the specific diagnostic value for all of them has not yet been systematically studied. Epinephrine challenge can be helpful in identifying concealed LQTS. Cardiac MRI may be used in the diagnosis of patients with arrhythmogenic right ventricular cardiomyopathy. Isoproterenol testing is commonly used in the EP lab to bring out arrhythmias. Exercise testing may be helpful in the diagnosis of CPVT.

28. A 10-year-old female with known LQTS type 1 presents with status epilepticus to the emergency department. She is on oral nadolol therapy. Her ECG shows sinus rhythm (120 bpm) and her resting QT interval is 500 msec. The ER doctor prepares to administer IV phenytoin and consults the cardiologist regarding the safety of phenytoin use in the patient. Which of the following statements is accurate with regard to the current patient scenario?

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Nov 19, 2022 | Posted by in CARDIOLOGY | Comments Off on Cardiac Pharmacology

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