TABLE IV-114 Risk Factors for Active Tuberculosis Among Persons Who Have Been Infected With Tubercle Bacilli 9 page

A. Hand grip

B. Leaning forward while sitting

C. Lying left side down

D. Squatting

E. Valsalva maneuver

V-71. A 62-year-old woman presents to your office with dyspnea of 4 months duration. She has a history of monoclonal gammopathy of unclear significance (MGUS) and has been lost to follow-up for the past 5 years. She is able to do only minimal activity before she has to rest but has no symptoms at rest. She has developed orthopnea but denies paroxysmal nocturnal dyspnea. She complains of fatigue, lightheadedness, and lower extremity swelling. On examination, blood pressure is 110/90 mmHg and heart rate is 94 beats/min. Jugular venous pressure is elevated, and the jugular venous wave does not fall with inspiration. An S₃ and S₄ are present, as well as a mitral regurgitation murmur. The point of

maximal impulse is not displaced. Abdominal examination is significant for ascites and a large, tender, pulsatile liver. Chest radiograph shows bilateral pulmonary edema. An electrocardiogram shows an old left bundle branch block. Which clinical features differentiate constrictive pericarditis from restrictive cardiomyopathy?

A. Elevated jugular venous pressure

B. Kussmaul’s sign

C. Narrow pulse pressure

D. Pulsatile liver

E. None of the above

V-72. You are evaluating a new patient in the clinic. The 25-year-old patient was diagnosed with “heart failure” in another state and has since relocated. He has New York Heart Association class II symptoms and denies angina. He presents for evaluation and management. The patient has been wheelchair bound for many years and has severe scoliosis. He has no family history of hyperlipidemia. His physical examination is notable for bilateral lung crackles, an S₃, and no cyanosis. An electrocardiogram (ECG)

is obtained in the clinic and shows tall R waves in V₁ and V₂ with deep Qs in V₅ and V₆. An echocardio-gram reports severe global left ventricular dysfunction with reduced ejection fraction. What is the most likely diagnosis?

A. Amyotrophic lateral sclerosis

B. Atrial septal defect

C. Chronic thromboembolic disease

D. Duchenne’s muscular dystrophy

E. Ischemic cardiomyopathy

V-73. A 35-year-old woman with a history of tobacco abuse presents to the emergency department because of severe chest pain radiating to both arms. The pain began 8 hours ago and is worse with inspiration. She has been unable to lie down as this markedly exacerbates the pain, but she feels better with sitting forward. Examination is notable for a heart rate of 96 beats/min, blood pressure of 145/78 mmHg, and oxygen saturation of 98%. Lungs are clear and a friction rub with three components is audible and is best heard at the left lower sternal border. Which of the following are most likely to be found on her ECG?

A. Diffusely inverted T waves in the precordial leads

B. PR elevation in leads II, III, and aVF

C. Sinus tachycardia

D. ST-segment elevation in I, aVL, and V₂–V₆ with upward concavity and reciprocal depressions

in aVR

E. ST-segment elevation V₁–V₆ with convex curvature and reciprocal depressions in aVR

V-74. Which of the following statements is true regarding pulsus paradoxus?

A. It consists of a greater than 15 mmHg increase in systolic arterial pressure with inspiration.

B. It may be found in patients with severe obstructive lung disease.

C. It is the reversal of a normal phenomenon during inspiration.

D. It results from right ventricular distention during expiration resulting in compression of the left
ventricular volume and subsequent reduction in systolic pulse pressure.

E. All of the above are true.

V-75. Which of the following are features of Beck’s triad in cardiac tamponade?

A. Hypotension, electrical alternans, prominent x-descent in neck veins

B. Hypotension, muffled heart sounds, electrical alternans

C. Hypotension, muffled heart sounds, jugular venous distention

D. Kussmaul’s sign, hypotension, muffled heart sounds

E. Muffled heart sounds, hypotension, friction rub

V-76. A 35-year-old woman is admitted to the hospital with malaise, weight gain, increasing abdominal girth, and edema. The symptoms began about 3 months ago and gradually progressed. The patient reports an increase in waist size of approximately 15 cm. The swelling in her legs has gotten increasingly worse such that she now feels her thighs are swollen as well. She has dyspnea on exertion and two-pillow orthopnea. She has a past history of Hodgkin’s disease diagnosed at age 18. She was treated at that time with chemotherapy and mediastinal irradiation. On physical examination, she has temporal wasting and appears chronically ill. Her current weight is 96 kg, which reflects an increase of 11 kg over the past 3 months. Her vital signs are normal. Her jugular venous pressure is approximately 16 cm, and the neck veins do not collapse on inspiration. Heart sounds are distant. There is a third heart sound heard shortly after aortic valve closure. The sound is short and abrupt and is heard best at the apex. The liver is enlarged and pulsatile. Ascites is present. There is pitting edema extending throughout the lower extremities and onto the abdominal wall. Echocardiogram shows pericardial thickening, dilatation of the inferior vena cava and hepatic veins, and abrupt cessation of ventricular

filling in early diastole. Ejection fraction is 65%. What is the best approach for treatment of this patient?

A. Aggressive diuresis only

B. Cardiac transplantation

C. Mitral valve replacement

D. Pericardial resection

E. Pericardiocentesis

V-77. A 19-year-old previously healthy hockey player is defending the goal when he is hit in the left chest with a hockey puck. He immediately collapses to the ice. His coach runs to his side and finds him unresponsive and without a pulse. Which of the following is most likely responsible for this syndrome?

A. Aortic rupture

B. Cardiac tamponade

C. Commotio cordis

D. Hypertrophic cardiomyopathy

E. Tension pneumothorax

V-78. A 48-year-old white man is seen in the clinic for a routine physical examination. He reports no complaints. Examination shows a blood pressure of 134/82 mmHg with a normal heart rate. BMI is 31 kg/m². The remainder of his physical examination is normal. Which of the following is true regarding lifestyle modification?

A. Brisk walking for as little as 10 minutes, 4 days per week will lower his blood pressure to
within the normal range.

B. Dietary NaCl restriction of less than 6 g per day will reduce his blood pressure.

C. Lifestyle modification will have no effect on his blood pressure.

D. Reduction of alcohol consumption to three or fewer drinks per day will decrease his blood
pressure.

E. Weight loss of approximately 9 kg can be expected to bring his blood pressure to within the
normal limit.

V-79. A 46-year-old white female presents to your office with concerns about her diagnosis of hypertension 1 month previously. She asks you about her likelihood of developing complications of hypertension, including renal failure and stroke. She denies any past medical history other than hypertension and has no symptoms that suggest secondary causes. She currently is taking hydrochlorothiazide 25 mg/d. She smokes half a pack of cigarettes daily and drinks alcohol no more than once per week. Her family history is significant for hypertension in both parents. Her mother died of a cerebrovascular accident. Her father is alive but has coronary artery disease and is on hemodialysis. Her blood pressure is 138/90 mmHg. Body mass index is 23. She has no retinal exudates or other signs of hypertensive retinopathy. Her point of maximal cardiac impulse is not displaced but is sustained. Her rate and rhythm are regular and without gallops. She has good peripheral pulses. An electrocardiogram reveals an axis of –30 degrees with borderline voltage criteria for left ventricular hypertrophy. Creati-nine is 1.0 mg/dL. Which of the following items in her history and physical examination is a risk factor for a poor prognosis in a patient with hypertension?

A. Family history of renal failure and cerebrovascular disease

B. Persistent elevation in blood pressure after the initiation of therapy

C. Ongoing tobacco use

D. Ongoing use of alcohol

E. Presence of left ventricular hypertrophy on ECG

V-80. A 28-year-old female has hypertension that is difficult to control. She was diagnosed at age 26. Since that time she has been on increasing amounts of medication. Her current regimen consists of labetalol 1000 mg bid, lisinopril 40 mg qd, clonidine 0.1 mg bid, and amlodipine 5 mg qd. On physical examination she appears to be without distress. Blood pressure is 168/100 mmHg, and heart rate is 84 beats/min. Cardiac examination is unremarkable, without rubs, gallops, or murmurs. She has good peripheral pulses and has no edema. Her physical appearance does not reveal any hirsutism, fat maldistribution, or abnormalities of genitalia. Laboratory studies reveal a potassium of 2.8 meq/dL and a serum bicarbonate of 32 meq/dL. Fasting blood glucose is 114 mg/dL. What is the likely diagnosis?

A. Congenital adrenal hyperplasia

B. Fibromuscular dysplasia

C. Cushing’s syndrome

D. Conn’s syndrome

E. Pheochromocytoma

V-81. What is the best way to diagnose this disease in question V-80?

A. Renal vein renin levels

B. 24-hour urine collection for metanephrines

C. Magnetic resonance imaging of the renal arteries

D. 24-hour urine collection for cortisol

E. Plasma aldosterone/renin ratio

V-82. Which of the following patients with aortic dissection or hematoma is best managed without surgical therapy?

A. A 74-year-old male with a dissection involving the root of the aorta.

B. A 45-year-old female with a dissection involving the aorta distal to the great vessel origin but
cephalad to the renal arteries.

C. A 58-year-old male with aortic dissection involving the distal aorta and the bilateral renal
arteries.

D. A 69-year-old male with an intramural hematoma within the aortic root.

E. All of the above patients require surgical management of their aortic disease.

V-83. A 68-year-old male presents to your office for routine follow-up care. He reports that he is feeling well and has no complaints. His past medical history is significant for hypertension and hypercholesterolemia. He continues to smoke a pack of cigarettes daily. He is taking chlorthalidone 25 mg daily, atenolol 25 mg daily, and pravastatin 40 mg nightly. Blood pressure is 133/85 mmHg, and heart rate is 66 beats/min. Cardiac and pulmonary examinations are unremarkable. A pulsatile

abdominal mass is felt just to the left of the umbilicus and measures approximately 4 cm. You confirm the diagnosis of abdominal aortic aneurysm by CT imaging. It is located infrarenally and measures 4.5 cm. All the following are true about the patient’s diagnosis EXCEPT:

A. The 5-year risk of rupture of an aneurysm of this size is 1–2%.

B. Surgical or endovascular intervention is warranted because of the size of the aneurysm.

C. Infrarenal endovascular stent placement is an option if the aneurysm experiences continued
growth in light of the location of the aneurysm infrarenally.

D. Surgical or endovascular intervention is warranted if the patient develops symptoms of recurrent
abdominal or back pain.

E. Surgical or endovascular intervention is warranted if the aneurysm expands beyond 5.5 cm.

V-84. A 32-year-old female is seen in the emergency department for acute shortness of breath. A helical CT shows no evidence of pulmonary embolus, but incidental note is made of dilatation of the ascending aorta to 4.3 cm. All the following are associated with this finding EXCEPT:

A. Syphilis

B. Takayasu’s arteritis

C. Giant cell arteritis

D. Rheumatoid arthritis

E. Systemic lupus erythematosus

V-85. A 68-year-old man with a history of coronary artery disease is seen in his primary care clinic for complaint of cough with sputum production. His care provider is concerned about pneumonia, so a chest radiograph is ordered. On the chest radiograph, the aorta appears tortuous with a widened mediastinum. A contrast-enhanced CT of the chest confirms the presence of a descending thoracic aortic aneurysm measuring 4 cm with no evidence of dissection. What is the most appropriate management of this patient?

A. Consult interventional radiology for placement of an endovascular stent.

B. Consult thoracic surgery for repair.

C. No further evaluation is needed.

D. Perform yearly contrast-enhanced chest CT and refer for surgical repair when the aneurysm size
is greater than 4.5 cm.

E. Treat with beta blockers, perform yearly contrast-enhanced chest CT, and refer for surgical
repair if the aneurysm grows more than 1 cm/year.

V-86. A 37-year-old woman with no significant past medical history except for a childhood murmur is evaluated for severe pain of sudden onset in her right lower extremity. Examination is notable for a young, uncomfortable woman with normal vital signs except for a heart rate of 110 beats/min. Right leg has pallor distal to the right knee and is cold to the touch, and the dorsalis pedis pulse is absent. Which of the following studies is likely to diagnose the underlying reason for the patient’s presentation?

A. Angiography of right lower extremity

B. Blood cultures

C. Echocardiogram with bubble study

D. Serum c-ANCA

E. Venous ultrasound of right upper extremity

ANSWERS

V-1. The answer is B. (Chaps. 227, 250) Pulmonary hypertension is associated with a loud second heart sound that is heard to be louder than the first heart sound at the cardiac base. In idiopathic pulmonary arterial hypertension, there is no associated congenital lesion, such as atrial septal defect (ASD). In ASD, the components of the second heart sound, aortic and pulmonic valve closure, do not alter their timing with respect to respiratory cycle and are always widely split, and thus are described as “fixed split.” In idiopathic pulmonary arterial hypertension, the components of the second heart sound are nearly superimposed and loud; often there is little respiratory variation. The soft systolic murmur at the left lower sternal border of tricuspid regurgitation is nearly always present in pulmonary hypertension of all etiologies. Idiopathic pulmonary arterial hypertension, by definition, is not associated with a parenchymal lung disease such as emphysema. Patients with idiopathic pulmonary arterial hypertension should not have physical findings associated with chronic airways disease.

V-2. The answer is A. (Chap. 227) The patient is very likely to have pericardial tamponade from metastatic cancer as suggested by her elevated neck veins, heart shadow shape and size, and predisposing condition. Because of the exaggerated interventricular dependence, the normal (<10 mmHg) fall in systemic blood pressure with inspiration is exaggerated (often >15 mmHg) with cardiac tamponade. This is referred to as pulsus paradoxus, though it is in fact an augmentation of a normal finding. Kussmaul’s sign, or a lack of fall of the jugular venous pressure with inspiration, usually denotes a lack of compliance in the right ventricle, as seen most frequently in constrictive pericarditis, though it may be found in restrictive cardiomyopathy or massive pulmonary embolism. A rapid y-descent, which follows the peak of the v wave, of jugular venous pressure tracing is indicative of cardiac tamponade. Pulsus parvus et tardus, or small and slow arterial pulsation, is a late finding in aortic stenosis. Late diastolic murmur and opening snap is found in mitral stenosis.

V-3. The answer is A. (Chap. 227) A fourth heart sound indicates left ventricular presystolic expansion and is common among patients in whom active atrial contraction is important for ventricular filling. A fourth heart sound is not found in atrial fibrillation. An irregular heart rate is characteristic of atrial fibrillation. The irregular rate is often characterized as “irregularly irregular.” A third heart sound occurs during the rapid filling phase of ventricular diastole and indicates heart failure. Reversed splitting of the second heart sound occurs with left bundle branch block, as this patient has. Finally, pulsus alternans is beat-to-beat variability in pulse amplitude. It is present when only every other Korotkoff sound is audible as the cuff pressure is lowered slowly. It is thought to be due to cyclic changes in intracellular calcium and action potential duration and is associated with severe left ventricular failure.

V-4. The answer is A. (Chap. 227) The presentation of this patient is consistent with the diagnosis of acute valvular dysfunction due to infective endocarditis. The presence of a widened pulse pressure and diastolic murmur heard best along the lower sternal border suggests aortic regurgitation. Panel C of Figure V-4B shows a typical bisferiens pulse that is characteristic of aortic regurgitation. With a

bisferiens pulse, there are two distinct pulsations that can be palpated with systole. The initial pulse represents an exaggerated percussion wave reflecting the increased stroke volume that occurs in aortic regurgitation, with the second peak reflecting the tidal, or anacrotic, wave.

Infective endocarditis causes loss of valvular integrity and acutely causes valvular regurgitation. Of the other options, both mitral regurgitation and tricuspid regurgitation (choice E) would cause systolic and not diastolic murmurs. A hyperkinetic pulse may occur in these conditions, particularly if associated with fever or sepsis. With a hyperkinetic pulse the usual dichrotic notch is more pronounced, as seen in panel E of the figure. Mitral stenosis causes a diastolic murmur but is not a common lesion associated with infective endocarditis, unless underlying valvular stenosis was present prior to acquiring the infection. It is not associated with a bisferiens pulse. Aortic stenosis is associated with pulsus parvus et tardus, with a delayed and prolonged carotid upstroke as shown in panel B of the figure. Aortic stenosis has an associated harsh crescendo-decrescendo systolic murmur.

FIGURE V-4B Schematic diagrams of the configurational changes in carotid pulse and their differential diagnoses. Heart sounds are also illustrated. A. Normal. S₄, fourth heart sound; S₁, first

heart sound; A₂, aortic component of second heart sound; P₂, pulmonic component of second heart

sound. B. Aortic stenosis. Anacrotic pulse with slow upstroke to a reduced peak. C. Bisferiens pulse with two peaks in systole. This pulse is rarely appreciated in patients with severe aortic regurgitation. D. Bisferiens pulse in hypertrophic obstructive cardiomyopathy. There is a rapid upstroke to the first peak (percussion wave) and a slower rise to the second peak (tidal wave). E. Dicrotic pulse with peaks in systole and diastole. This waveform may be seen in patients with sepsis

or during intraaortic balloon counter-pulsation with inflation just after the dicrotic notch. [From K Chatterjee, W Parmley (eds): Cardiology: An Illustrated Text/Reference. Philadelphia, JB Lippincott, 1991.]

V-5. The answer is A. (Chap. 227) Peripheral arterial disease (PAD) affects 5–8% of Americans, with increasing incidence with age. Over the age of 65, the incidence of PAD rises to between 12% and 20%. The primary symptom of PAD is claudication. As this patient describes, claudication occurs with ambulation and is often described as a crampy to aching pain that is relieved with rest. On physical examination, those with PAD often have diminished peripheral pulses, delayed capillary refill, and hair loss in the distal extremities. The skin is often cool to the touch with a thin, shiny appearance. In severe PAD, pain in the extremities occurs at rest. Diagnosis of PAD can be suggested by these findings and should be documented by determination of the ankle-brachial index (ABI), as physical examination alone is insufficient to diagnose PAD. Although lack of a palpable pulse suggests critical ischemia, it is not diagnostic. To perform an ABI, blood pressures are determined in the arm and the lower extremities. Either the dorsalis pedis or posterior tibial pulses can be used. The ABI is calculated by dividing the ankle systolic pressure by the brachial systolic pressure. A resting ABI less than 0.9 is abnormal, but critical ischemia with rest pain does not occur until the ABI is less than 0.3. In individuals with heavily calcified blood vessels, the ABI can be abnormally elevated (ABI >1.2) when PAD is present. In this situation, toe pressures to determine ABI or employing imaging techniques such as MRI or arteriography should be considered. Lower extremity edema is suggestive of congestive heart failure, not PAD.

V-6. The answer is F. (Chap. 227) When a murmur of uncertain cause is identified on physical examination, a variety of physiologic maneuvers can be used to assist in the elucidation of the cause. Commonly used physiologic maneuvers include change with respiration, Valsalva maneuver, position, and exercise. In hypertrophic cardiomyopathy, there is asymmetric hypertrophy of the interventricular septum, which creates a dynamic outflow obstruction. Maneuvers that decrease left-ventricular filling will cause an increase in the intensity of the murmur, whereas those that increase left-ventricular filling will cause a decrease in the murmur. Of the interventions listed, both standing and a Valsalva maneuver will decrease venous return and subsequently decrease left ventricular filling, resulting in an increase in the loudness of the murmur of hypertrophic cardiomyopathy. Alternatively, squatting will increase venous return and thus decrease the murmur. Maximum handgrip exercise also will result in a decreased loudness of the murmur.

V-7. The answer is B. (Chap. 228) Left bundle branch, defined by QRS interval greater than 120 milliseconds with typical pattern in V₁ and V₆, is associated with four conditions: coronary heart

disease, hypertensive heart disease, aortic valve disease, and cardiomyopathy. In all cases, the left bundle branch block is associated with increased risk of cardiovascular morbidity and mortality. These conditions share left ventricular pathology. In contrast, right bundle branch block is associated with congenital heart disease, pulmonary vascular disease, and less frequently valvular heart disease.

V-8. The answer is D. (Chap. 228) The classic findings of hypokalemia are prominent U waves due to prolonged ventricular repolarization. Scooped ST segments are commonly seen with digoxin toxicity. Low P wave amplitude is found in early hyperkalemia. Prolonged QT intervals are often due to drug

toxicity such as tricyclic antidepressant overdose, procainamide, quinidine disopyramide, and phenothiazines. Finally, Osborne waves, or convex elevation of the J point, are found in severe hypothermia and are due to repolarization prolongation.

V-9. The answer is D. (Chaps. 228, 237, and 250) The patient presents from a country with likely low rates of treatment for childhood streptococcal infection and was subsequently at high risk for rheumatic heart disease. Her large pulmonary arteries in the absence of parenchymal infiltrates suggests pulmonary hypertension and her ECG shows right ventricular hypertrophy, characterized by a relatively tall R wave in lead V₁, or R greater than or equal to S wave. This is highly likely to be due to mitral

stenosis. While aortic stenosis and regurgitation are possible causes, these are less likely. Tricuspid stenosis is not associated with right ventricular hypertrophy. Left ventricular systolic failure may cause pulmonary venous hypertension, but more commonly is associated with evidence of left heart failure on examination.

V-10. The answer is D. (Chaps. 228 and e28) This ECG shows a short ST segment that is most prominent in V₂, V₃, V₄, and V₅. Hypercalcemia, by shortening the duration of repolarization, abbreviates the total time from depolarization through repolarization. This is manifested on the surface ECG by a short QT interval. In this scenario, the hypercalcemia is due to the rhabdomyolysis and renal failure. Fluids and a loop diuretic are an appropriate therapy for hypercalcemia. Hemodialysis is seldom indicated. Hemodialysis is indicated for significant hyperkalemia, which may also develop after rhabdomyolysis, manifest by “tenting” of the T waves or widening of the QRS. Classic ECG manifestations of a pulmonary embolus (S₁, Q₃, T₃ pattern) are infrequent in patients with pulmonary embolism (PE), though the changes may be seen with massive PE. There are no signs of myocar-dial ischemia on this ECG, which would make coronary catheterization and 18-lead ECG interpretation of low yield.

V-11. The answer is D. (Chap. 228) Hyperkalemia leads to partial depolarization of cardiac cells. As a result, there is slowing of the upstroke of the action potential as well as reduced duration of repolarization. The T wave becomes peaked, the RS complex widens and may merge with the T wave (giving a sine-wave appearance), and the P wave becomes shallow or disappears. Prominent U waves are associated with hypokalemia; ST-segment prolongation is associated with hypocalcemia.

V-12. The answer is C. (Chaps. 228 and 238) The ECG shows slight right axis deviation and low voltage. These changes are typical of emphysema when the thorax is hyperinflated with air and the flattened diaphragm pulls the heart inferiorly and vertically. An acute central nervous system (CNS) event such as a subarachnoid hemorrhage may cause QT prolongation with deep, wide inverted T waves. Hyperkalemia will cause peaked narrowed T waves or a wide QRS complex. Patients with hypertrophic cardiomyopathy will have left ventricular hypertrophy and widespread deep, broad Q waves.

V-13. The answer is E. (Chaps. 228 and e30) This ECG tracing shows the triad of a short PR interval, wide QRS, and delta waves (seen best in leads I, II, and V₅) consistent with Wolff-Parkinson-White

(WPW) syndrome. Patients with WPW syndrome are commonly diagnosed asymptomatically when an ECG is performed showing the classic findings. Symptoms are due to conduction via an accessory pathway and include tachypalpitations, lightheadedness, syncope, cardiopulmonary collapse, and

sudden cardiac death. Life-threatening presentations are usually due to the development of atrial fibrillation or atrial flutter with 1:1 conduction, both of which can precipitate ventricular fibrillation. Unstable angina is mainly associated with ST-segment abnormalities, although conduction abnormalities may be seen. Pulmonary embolism, which may cause hemoptysis and pleuritic chest pain, has nonspecific ECG findings including S₁Q₃T₃ (acute right ventricular failure) or T-wave abnormalities.

V-14. The answer is E. (Chap. 228) The limb lead aVR generally has a negative deflection, as the primary vector for ventricular depolarization is directed down and away from this lead. Therefore, in the case of left ventricular hypertrophy the negative deflection, or S wave, would be expected to be larger without an effect on the R wave. There are multiple criteria for diagnosing left ventricular hypertrophy on ECG.

V-15. The answer is B. (Chaps. 228 and e30) This ECG tracing shows multifocal atrial tachycardia (MAT), right atrial overload, a superior axis, and poor R-wave progression in the precordial leads. There are varying P-wave morphologies (more than three morphologies) and P-P intervals. MAT is most commonly caused by COPD, but other conditions associated with this arrhythmia include coronary artery disease, congestive heart failure, valvular heart disease, diabetes mellitus, hypokalemia, hypomagnesemia, azotemia, postoperative state, and pulmonary embolism. Anemia, pain, and myocardial ischemia are also causes of tachycardia that should be considered when managing a new tachycardia. These states are usually associated with sinus tachycardia.

V-16. The answer is E. (Chap. 229) Doppler echocardiography uses ultrasound reflecting off moving red blood cells to determine flow velocity within a structure, in this case the heart or great vessels. Thus, it is most useful for determining abnormal flow or flow limitation. Specifically, it is useful in defining valvular regurgitation or stenosis, cardiac output when combined with the cross-sectional area, and diastolic filling of the ventricle. Heart failure with preserved ejection fraction is associated with impaired left ventricle relaxation in early diastole and subsequently there is reduced early transmitral flow compared to normal individuals. Although Doppler might be helpful to determine the physiologic consequence of pericardial effusion, i.e., tamponade, two-dimensional (2D) echocardiography is the preferred mode for effusion diagnosis. Similarly, 2D echocardiography is used to calculate ejection fraction and diagnose cardiac masses. Diagnosis of ischemia can be made with the addition of physiologic or pharmacologic stress to echocardiography, but not with Doppler echocardiography.

Date: 2016-04-22; view: 930