Cardiología Flashcards
This patient presents with syncope, orthostatic hypotension (drop of ≥ 20 mm Hg in systolic pressure from supine to standing), and a diastolic murmur over the apex, all of which are suspicious for an obstruction of the blood flow into the left ventricle.
Which of the following is the most likely cause of this patient’s presentation?
Cardiac myxomas are the most common primary cardiac tumor, commonly located in the left atrium. They may be pedunculated, in which case they often present with position-dependent symptoms of obstructed blood flow through the atrioventricular valves, or they may embolize. Additionally, patients may present with constitutional findings (e.g., weight loss, fever, or anemia). The typical auscultatory finding (also present in this patient) is an early diastolic “plop”, caused by a movement of the mobile tumor mass, followed by a mid-diastolic rumbling murmur best heard at the apex that results from the obstructed blood flow through the mitral valve, and mimics the murmur of mitral stenosis.
This patient’s presentation of shock (hypotension, tachycardia, altered mental status) after severe blunt chest trauma in the setting of a motor vehicle accident is highly suggestive of blunt thoracic aortic injury. Which structure is most likely injured?
Aortic Isthmus
A 55-year-old woman comes to the emergency room 30 minutes after the sudden onset of chest pain radiating to the left shoulder. Prior to the onset of her symptoms, she was lying in bed because of a migraine headache. Episodes of similar chest pain usually resolved after a couple of minutes. She has smoked one pack of cigarettes daily for 20 years. Her only medication is sumatriptan. An ECG shows ST-segment elevations in the anterior leads. Serum troponins are negative on two successive blood draws and ECG shows no abnormalities 30 minutes later. Administration of which of the following is most likely to prevent further episodes of chest pain in this patient?
Calcium channel blockers (CCBs) such as diltiazem are the first-line treatment for vasospastic angina.
A 51-year-old man comes to the emergency department because of a 3-day history of shortness of breath, fever, and chills. He has no history of serious illness. His temperature is 39.5°C (103.1°F). Physical examination shows a grade 4/6, holosystolic, blowing murmur over the apex that radiates to the axilla. Crackles are heard in both lower lung fields. Examination of the extremities shows several nontender, nonblanching, erythematous macules on the palms and soles. Histopathologic examination of these macules is most likely to show which of the following?
Microabscesses with neutrophil infiltration of capillaries and areas of hemorrhage are characteristic of the Janeway lesions seen in patients with infective endocarditis. They are thought to be caused by septic microemboli from valve vegetations and, among other vascular phenomena, constitute a minor clinical criterion for the Duke criteria in infective endocarditis. Janeway lesions are more common in acute endocarditis than in subacute endocarditis.
The severe hypertrophy of the left ventricle seen in the autopsy images of this young man who died of sudden cardiac death confirms a diagnosis of hypertrophic cardiomyopathy. The patient’s condition is most likely associated with which of the following pathophysiologic changes?
Marked reduction in compliance (physiology) of the left ventricular wall and reduced chamber volume due to left ventricular hypertrophy are key features of hypertrophic cardiomyopathy (HCM).
An autopsy of a patient’s heart who recently died in a motor vehicle accident shows multiple nodules near the line of closure on the ventricular side of the mitral valve leaflet. Microscopic examination shows that these nodules are composed of immune complexes, mononuclear cells, and thrombi interwoven with fibrin strands. These nodules are most likely to be found in which of the following patients?
A facial rash and symmetric, nonerosive polyarthritis in a middle-aged female is highly suspicious for systemic lupus erythematosus. Systemic inflammation in SLE can lead to the deposition of circulating sterile immune complexes with platelet thrombi on either side of valve leaflets in what is known as Libman-Sacks endocarditis.
This patient’s general fatigue, hypertension, low-grade systolic ejection murmur, lower-extremity claudication, headaches, and recurrent epistaxis together suggest ______.
Further evaluation of this patient is most likely to show which of the following findings?
coarctation of the aorta (CoA)
In patients with CoA, delayed or even absent lower extremity pulses are expected distal to the stenotic portion of the aorta
This patient has symptoms consistent with acute pericarditis, including a pericardial friction rub on auscultation and sharp, pleuritic chest pain that worsens with inspiration and improves with sitting and leaning forward. Given his history of myocardial infarction (MI) 2 days ago, it is most likely a subtype known as fibrinous pericarditis.
Histopathological examination of the affected tissue is most likely to show which of the following findings?
Neutrophilic infiltration is seen 1–3 days after a myocardial infarction (MI) on histopathological examination.
A 61-year-old woman dies unexpectedly. She had not seen a physician in 10 years. Examination of the heart during autopsy shows hypertrophy of the left ventricular wall and enlargement of the left ventricular chamber. Microscopic examination shows lengthening of individual muscle fibers due to duplication of sarcomeres in series. Which of the following is the most likely underlying cause of these findings?
Increased left ventricular end-diastolic volume (preload) results in dilation of the left ventricle in an attempt to increase myocardial contractility to maintain cardiac output (Frank-Starling mechanism). This compensatory mechanism ultimately fails, and the continuous strain of increased blood volume in the LV triggers myocardial remodeling that results in eccentric hypertrophy (addition of sarcomeres in series), eventually leading to a dilated cardiomyopathy and reduced ejection fraction.
A 13-year-old boy is brought to the emergency department by ambulance after suddenly losing consciousness while playing in a soccer tournament. The patient has had 2 episodes of syncope without a discernable trigger over the past year. He has been otherwise healthy. His father died suddenly at the age of 37. He reports lightheadedness and suddenly loses consciousness when physical examination is attempted. Radial pulses are not palpable. An ECG shows ventricular tachycardia with peaks of the QRS twisting around the isoelectric line. Which of the following is the most likely underlying cause of this patient’s condition?
Torsades de pointes is most often due to long QT syndrome, which may be acquired or congenital. Congenital long QT syndrome can be caused by mutations of genes coding for cardiac potassium, sodium, or calcium ion channels. These mutations cause ventricular action potentials to be prolonged, leading to a lengthened QT interval on ECG. The two most common long QT syndromes are Romano-Ward syndrome and Jervell and Lange-Nielsen (JLN) syndrome.
This patient has features of pulmonary arterial hypertension (PAH; group 1 pulmonary hypertension), including progressive dyspnea, enlarged pulmonary vessels, enlarged right side of the heart, and a history of systemic sclerosis (a cause of PAH). Elevated right ventricular and pulmonary arterial pressures confirm the diagnosis. Tadalafil is a phosphodiesterase type 5 inhibitor (PDE5 inhibitor) that has been shown to improve outcomes in patients with PAH. The expected beneficial effect of this drug is most likely due to which of the following actions?
Enhanced activity of nitric oxide (NO) is the mechanism of action of PDE5 inhibitors, including tadalafil.
This patient’s cloudy, foul-smelling urine, tachycardia, and hypotension suggest septic shock. Infection should always be considered as a cause of altered mental status in an older patient. His vitals are: temperature is 37.9°C (100.2°F), pulse is 110/min, and blood pressure is 80/50 mm Hg. This patient is most likely to have which of the following hemodynamic profiles?
This profile is suggestive of distributive shock, which is a collective term for shock that results in pathologic vasodilation, leading to decreased SVR. The most common etiology is septic shock (in this case likely due to urinary tract infection), but it can also be caused by neurogenic shock or anaphylactic shock. Circulating cytokines and bacterial toxins cause pathologic vasodilation and lead to decreased SVR (afterload), as well as decreased CVP and PCWP (preload). Consequently, there is an increase in heart rate aimed at increasing cardiac output. Patients with septic shock often have warm, flushed skin as a result of this pathophysiology. In the late stage of septic shock, there may be a decrease in cardiac output and therefore patients may present with cold, pale skin with a delayed capillary refill (see “Overview of the types of shock” table).
A previously healthy 33-year-old woman comes to the emergency department because she could feel her heart racing intermittently for the past 2 hours. Each episode lasts about 10 minutes. She does not have any chest pain. Her mother died of a heart attack and her father had an angioplasty 3 years ago. She has smoked a half pack of cigarettes daily for 14 years. She drinks one to two beers daily. She appears anxious. Her temperature is 37.0°C (98.6°F), pulse is 190/min, and blood pressure is 104/76 mm Hg. The lungs are clear to auscultation. Cardiac examination shows no murmurs, rubs, or gallops. An ECG showing regular narrow QRS complexes without P waves indicates AV nodal reentrant tachycardia (AVNRT), a type of paroxysmal supraventricular tachycardia (PSVT). Which of the following is the most appropriate initial step in management?
Vagal maneuvers are the initial step in the management of a stable patient with PSVT because they are quick, can be performed by the patient, and have no side effects. Common maneuvers are the Valsalva maneuver and carotid massage. The stimulated vagus nerve then acts on the sinoatrial and atrioventricular nodes, which slows the heart rate and reduces conduction velocity. Should vagal maneuvers fail, other options in the acute management phase include adenosine, beta blockers, and calcium channel blockers.
A previously healthy 22-year-old woman comes to the emergency department because of several episodes of palpitations that began 5 days ago. The palpitations are intermittent in nature, with each episode lasting 5–10 seconds. She states that during each episode she feels as if her heart is going to “spin out of control.” She has recently been staying up late to study for her final examinations. She does not drink alcohol or use illicit drugs. She appears anxious. Her temperature is 37.0°C (98.6°F), pulse is 75/min, and blood pressure is 110/75 mm Hg. Physical examination shows no abnormalities. ECG shows normal P wave morphology with intermittent doublets of broad, monomorphic QRS complexes (suggest benign premature ventricular contractions (PVCs).). Which of the following is the most appropriate next step in management?
PVCs are often asymptomatic but can manifest with a feeling of “skipped beats.” If PVCs are frequent, symptoms such as palpitations, lightheadedness, dizziness, and irregular heartbeat, can occur. The PVCs in this healthy young patient are most likely triggered by lack of sleep and stress due to studying. Other common triggers include caffeine, alcohol, or nicotine consumption. In patients with frequent or long episodes of PVCs, further diagnostic studies (e.g., echocardiography) are indicated to assess for underlying heart disease. Because this is the first incident of PVCs in this patient, no treatment is necessary at this time; however, observation and rest are recommended to monitor for and potentially reduce the frequency of episodes.
