The Quizzes about Chest Pain and Cardiac Dysrhythmias – Part 1 (20 test)

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A 59-year-old man presents to the emergency department (ED) complaining of new-onset chest pain that radiates to his left arm. He has a history of hypertension, hypercholesterolemia, and a 20-pack-year smoking history. His electrocardiogram (ECG) is remarkable for T-wave inversions in the lateral leads. Which of the following is the most appropriate next step in management?

The patient’s presentation is classic for an ACS. He has multiple risk factors with T-wave abnormalities on his ECG. The most appropriate initial management includes placing the patient on a cardiac monitor to detect dysrhythmias, establish intravenous access, provide supplemental oxygen, and administer aspirin. If the patient is having active chest pain in the ED, sublingual nitroglycerin or morphine should be administered until the pain resolves. This decreases wall tension and myocardial oxygen demand. A common mnemonic used is MONA ( Morphine, Oxygen, Nitroglycerin, Aspirin) greets chest pain patients at the door.

A 36-year-old woman presents to the ED with sudden onset of left-sided chest pain and mild shortness of breath that began the night before. She was able to fall asleep without difficulty but woke up in the morning with persistent pain that is worsened upon taking a deep breath. She walked up the stairs at home and became very short of breath, which made her come to the ED. Two weeks ago, she took a 7-hour flight from Europe and since then has left-sided calf pain and swelling. What is the most common ECG finding for this patient’s presentation?

The patient most likely has a pulmonary thromboembolism (PE) that embolized from a thrombus in her left calf. The diagnosis of PE is usually made with a CT angiogram, echocardiogram, or a ventilation-perfusion scan. The most common ECG abnormalities in the setting of PE are tachycardia and nonspecific ST-T–wave abnormalities. Many other ECG abnormality may appear with equal likelihood, but none are sensitive or specific for PE. If ECG abnormalities are present, they may be suggestive of PE, but the absence of ECG abnormalities has no significant predictive value. Moreover, 25% of patients with proven PE have ECGs that are unchanged from their baseline state.

A 51-year-old man with a long history of hypertension presents to the ED complaining of intermittent chest palpitations lasting for a week. He denies chest pain, shortness of breath, nausea, and vomiting. He recalls feeling similar episodes of palpitations a few months ago but they resolved. His blood pressure (BP) is 130/75 mm Hg, heart rate (HR) is 130 beats per minute, respiratory rate (RR) is 16 breaths per minute, and oxygen saturation is 99% on room air. An ECG is seen below. Which of the following is the most appropriate next step in management?

Atrial fibrillation (AF) is a rhythm disturbance of the atria that results in irregular, chaotic, ventricular waveforms. This chaotic activity can lead to reduced cardiac output from a loss of coordinated atrial contractions and a rapid ventricular rate, both of which may limit diastolic filling and stroke volume of the ventricles. Atrial fibrillation may be chronic or paroxysmal, lasting minutes to days. On the ECG, fibrillatory waves are accompanied by an irregular QRS pattern. The main ED treatment for stable atrial fibrillation is rate control. This can be accomplished by many agents, but the agent most commonly used is diltiazem, a CCB with excellent AV nodal blocking effects.

A 54-year-old woman presents to the ED because of a change in behavior at home. For the past 3 years, she has end-stage renal disease requiring dialysis. Her daughter states that the patient has been increasingly tired and occasionally confused for the past 3 days and has not been eating her usual diet. On examination, the patient is alert and oriented to person only. The remainder of her examination is normal. An initial 12-lead ECG is performed as seen on the following page. Which of the following electrolyte abnormalities best explains these findings?

Patients with end-stage renal disease, who require dialysis, are prone to electrolyte disturbances. This patient’s clinical picture is consistent with hyperkalemia. The ECG can provide valuable clues to the presence of hyperkalemia. As potassium levels rise, peaked T waves are the first characteristic manifestation. Further rises are associated with progressive ECG changes, including loss of P waves and widening of the QRS complex. Eventually the tracing assumes a sine-wave pattern, followed by ventricular fibrillation or asystole.

A 29-year-old tall, thin man presents to the ED after feeling short of breath for 2 days. In the ED, he is in no acute distress. His BP is 115/70 mm Hg, HR is 81 beats per minute, RR is 16 breaths per minute, and oxygen saturation is 98% on room air. Cardiac, lung, and abdominal examinations are normal. An ECG reveals sinus rhythm at a rate of 79. A chest radiograph shows a small right-sided (< 10% of the hemithorax) spontaneous pneumothorax. A repeat chest x-ray 6 hours later reveals a decreased pneumothorax. Which of the following is the most appropriate next step in management? a. Discharge the patient with follow-up in 24 hours


A 65-year-old man with a history of chronic hypertension presents to the ED with sudden-onset tearing chest pain that radiates to his jaw. His BP is 205/110 mm Hg, HR is 90 beats per minute, RR is 20 breaths per minute, and oxygen saturation is 97% on room air. He appears apprehensive. On cardiac examination you hear a diastolic murmur at the right sternal border. A chest x-ray reveals a widened mediastinum. Which of the following is the preferred study of choice to diagnose this patient’s condition?

The patient’s clinical picture of chronic hypertension, acute-onset tearing chest pain, diastolic murmur of aortic insufficiency, and chest x-ray with a widened mediastinum is consistent with an aortic dissection. The preferred study of choice is a transesophageal echocardiogram (TEE), which is highly sensitive. It can be quickly performed at the bedside and does not require radiation or contrast

A 47-year-old man with a history of hypertension presents to the ED complaining of continuous left-sided chest pain that began while snorting cocaine 1 hour ago. The patient states he never experienced chest pain in the past when using cocaine. His BP is 170/90 mm Hg, HR is 101 beats per minute, RR is 18 breaths per minute, and oxygen saturation is 98% on room air. The patient states that the only medication he takes is alprazolam to “calm his nerves.” Which of the following medications is contraindicated in this patient?

Patients with chest pain in the setting of cocaine use should be evaluated for possible myocardial ischemia. Patients suspected of ACS should be managed accordingly with oxygen, nitrates, morphine, aspirin, and benzodiazepines; however, a-adrenergic antagonist therapy is contraindicated. If β-adrenergic receptors are antagonized, α-adrenergic receptors are left unopposed and available for increased stimulation by cocaine. This may worsen into coronary and peripheral vasoconstriction, hypertension, and possibly ischemia. Therefore, benzodiazepines, which decrease central sympathetic outflow, are the cornerstone in treatment to relieve cocaine-related chest pain.

A 32-year-old woman presents to the ED with a persistent fever of 101°F over the last 3 days. The patient states that she used to work as a convenience store clerk but was fired 2 weeks ago. Since then, she has been using drugs intravenously daily. Cardiac examination reveals a heart murmur. Her abdomen is soft and nontender with an enlarged spleen. Chest radiograph reveals multiple patchy infiltrates in both lung fields. Laboratory results reveal white blood cells (WBC) 14,000/μL with 91% neutrophils, hematocrit 33%, and platelets 250/μL. An ECG reveals sinus rhythm with first-degree heart block. Which of the following is the most appropriate next step in management?

The incidence of endocarditis in the intravenous drug user (IVDU) is estimated to be 40 times that of the general population. Unlike the general population, endocarditis in IVDUs is typically right-sided with the majority of cases involving the tricuspid valve. Patients with IVDU-related endocarditis usually have no evidence of prior valve damage. Patients may present with fever, cardiac murmur, cough, pleuritic chest pain, and hemoptysis. Rightsided murmurs, which vary with respiration, are typically pathologic and more specific for the diagnosis. In patients with right-sided endocarditis and septic pulmonary emboli, pulmonary complaints, infiltrates on chest radiographs, and moderate hypoxia have been described in greater than 33% of patients; these symptoms and signs may mislead the physician to identify the lung as the primary source of infection. Blood cultures will be positive in more than 98% of IVDU-related endocarditis patients if 3 to 5 sets are obtained. Diagnosis generally requires microbial isolation from a blood culture or to demonstrate typical lesions on echocardiography. TTE is the most sensitive imaging modality for demonstrating vegetations and tricuspid valve involvement in IVDU-related endocarditis. Initial antibiotic treatment should be directed against Staphylococcus aureus and Streptococcus species.

A 61-year-old woman was on her way to the grocery store when she started feeling chest pressure in the center of her chest. She became diaphoretic and felt short of breath. On arrival to the ED by EMS, her BP is 130/70 mm Hg, HR is 76 beats per minute, and oxygen saturation is 98% on room air. The nurse gives her an aspirin and an ECG is performed as seen below. Which of the following best describes the location of this patient’s myocardial infarction (MI)?

The standard 12-lead ECG is the single best test to identify patients with acute MI upon presentation in the ED. It is important to identify the anatomic location of an acute MI to estimate the amount of endangered myocardium. The right coronary artery (RCA) supplies the AV node and inferior wall of the left ventricle in 90% of patients. Inferior wall MIs are characterized by ST elevation in at least two of the inferior leads (II, III, aVF). Reciprocal ST changes (eg, ST depression) in the anterior precordial leads (V 1-V4) in the setting of an inferior wall acute MI predict a larger infarct distribution, an increased severity of underlying coronary artery disease (CAD), more severe pump failure, and increased mortality. In general, the more elevated the ST segments and the more ST segments that are elevated, the more extensive the injury.

A 31-year-old man who works for a moving company presents to the ED because he thinks he was having a heart attack. He does not smoke, and jogs 3 days a week. His father died of a heart attack in his sixties. He describes a gradual onset of chest pain that is worse with activity and resolves when he is at rest. His HR is 68 beats per minute, BP is 120/70 mm Hg, and RR is 14 breaths per minute. On examination, his lungs are clear and there is no cardiac murmur. You palpate tenderness over the left sternal border at the third and fourth ribs. An ECG reveals sinus rhythm at a rate of 65. A chest radiograph shows no infiltrates or pneumothorax. Which of the following is the most appropriate next step in management?

The patient has costochondritis, an inflammatory process of the costochondral or costosternal joints that causes localized pain and tenderness. Any of the seven costochondral junctions may be affected, and more than one site is affected in 90% of cases. The second to fifth costochondral junctions are most commonly involved. In contrast to myocardial ischemia or infarction, costochondritis is a benign cause of chest pain, often with an insidious onset, and is an important consideration in the differential diagnosis for chest pain. Of note, 5% to 7% of patients with cardiac ischemia also have chest wall tenderness. The onset is often insidious. Chest wall pain with a history of repeated minor trauma or unaccustomed activity (eg, painting, moving furniture) is common. The goal of therapy is to reduce inflammation. NSAIDs are typically prescribed.


A 21-year-old woman presents to the ED complaining of lightheadedness. Her symptoms appeared 45 minutes ago. She has no other symptoms and is not on any medications. She has a medical history of mitral valve prolapse. Her HR is 170 beats per minute and BP is 105/55 mm Hg. Physical examination is unremarkable. After administering the appropriate medication, her HR slows down and her symptoms resolve. You repeat a 12-lead ECG that shows a rate of 89 beats per minute with a regular rhythm. The PR interval measures 100 milliseconds and there is a slurred upstroke of the QRS complex. Based on this information, which of the following is the most likely diagnosis?

WPW syndrome is caused by an accessory electrical pathway (ie, bundle of Kent) between the atria and ventricles. The primary significance of WPW syndrome is that it predisposes the individual to the development of reentry tachycardias. The classic ECG findings include a short PR interval (< 120 milliseconds), widened QRS interval (> 100 milliseconds), and a delta wave (slurred upstroke at the beginning of the QRS). When conduction occurs anterograde down the AV node and then retrograde up the accessory pathway (orthodromic), the ECG will appear normal. When the impulse occurs anterograde down the accessory pathway and retrograde up the AV node (antidromic), the QRS complex will be wide. In the presence of antidromic conduction (conduction first through the bypass tract), the normal slowing effect of the AV node is lost and rapid ventricular response rates (> 200 beats per minute) can occur. The most dangerous circumstance is in atrial fibrillation where impulses occur at a rate greater than 300 beats per minute. This can quickly lead to ventricular fibrillation. Procainamide is the drug most commonly associated with the acute treatment of WPW

A 55-year-old man presents to the ED with worsening weakness, muscle cramps, and paresthesias. His past medical history is significant for hypertension and diabetes. He smokes one pack of cigarettes per day. On examination, the patient is alert and oriented and diffusely weak. An ECG is seen below. Which of the following is the most important next step in management?

The patient has life-threatening hyperkalemia. His ECG shows a wide QRS complex, peaked T waves, and no P waves. At any moment the patient’s rhythm can go into ventricular fibrillation or asystole. There are many symptoms of hyperkalemia that are often difficult to discern from those of the primary condition that precipitated the hyperkalemia. Patients may begin with lethargy and weakness and progress to paralysis and areflexia. If there are no ECG abnormalities in a patient with hyperkalemia, treatment can start with potassium-binding resins (eg, Kayexalate). However, this patient requires immediate administration of calcium because he has an unstable cardiac rhythm. Calcium (gluconate or chloride) antagonizes the effects of potassium in the myocardium and briefly stabilizes the cardiac membrane. However, calcium will not lower the potassium level; in order to promote transcellular shifts and removal from the body, other measures will also be required.

While eating dinner, a 55-year-old man suddenly feels a piece of steak “get stuck” in his stomach. In the ED, he complains of dysphagia, is drooling, and occasionally retches. On examination, his BP is 130/80 mm Hg, HR is 75 beats per minute, RR is 15 breaths per minute, and oxygen saturation is 99% on room air. He appears in no respiratory distress. Chest x-ray is negative for air under the diaphragm. Which of the following is the most appropriate next step in management?

The patient most likely has a partial or complete obstruction in his lower esophagus secondary to the steak he ate. This usually occurs near the gastroesophageal junction. Administration of glucagon may cause enough relaxation of the esophageal smooth muscle to allow passage of the bolus in approximately 50% of patients. Its relaxant effect is limited to smooth muscle and therefore can only be used for impactions in the lower esophagus. If glucagon does not work, definitive management is with endoscopy.

A 59-year-old man presents to the ED with left-sided chest pain and shortness of breath that began 2 hours prior to arrival. He states the pain is pressure-like and radiates down his left arm. He is diaphoretic. His BP is 160/80 mm Hg, HR 86 beats per minute, and RR 15 breaths per minute. ECG reveals 2-mm ST-segment elevation in leads I, aVL, and V3 to V6. Which of the following is an absolute contraindication to receiving thrombolytic therapy?

Thrombolytic therapy (clotbusters) can be administered to patients having an acute ST-elevation MI that is within 12 hours from symptom onset. Contraindications to fibrinolytic therapy are those that increase the risk of hemorrhage. The most catastrophic complication is intracranial hemorrhage. Absolute contraindications include: • Previous hemorrhagic stroke • Known intracranial neoplasm • Active internal bleeding (excluding menses) • Suspected aortic dissection or pericarditis

A 67-year-old woman is brought to the ED by paramedics complaining of dyspnea, fatigue, and palpitations. Her BP is 80/50 mm Hg, HR is 139 beats per minute, and RR is 20 breaths per minute. Her skin is cool and she is diaphoretic. Her lung examination reveals bilateral crackles and she is beginning to have chest pain. Her ECG shows a narrow complex irregular rhythm with a rate in the 140s. Which of the following is the most appropriate immediate treatment for this patient?

This patient is hypotensive and exhibits signs and symptoms of heart failure (dyspnea, fatigue, respiratory crackles, and chest pain) and is in atrial fibrillation (irregular, narrow complex). Any patient with unstable vital signs with a tachydysrhythmia should receive a dose of sedation and undergo synchronized cardioversion starting at 100 J.


A 61-year-old woman with a history of congestive heart failure (CHF) is at a family picnic when she starts complaining of shortness of breath. Her daughter brings her to the ED where she is found to have an oxygen saturation of 85% on room air with rales halfway up both of her lung fields. Her BP is 185/90 mm Hg and pulse rate is 101 beats per minute. On examination, her jugular venous pressure (JVP) is 6 cm above the sternal angle. There is lower extremity pitting edema. Which of the following is the most appropriate first-line medication to lower cardiac preload?

This patient has decompensated CHF with pulmonary edema. Nitroglycerin is the most effective and most rapid means of reducing preload in a patient with CHF. Nitrates decrease myocardial preload and, to a lesser extent, afterload. Nitrates increase venous capacitance, including venous pooling, which decreases preload and myocardial oxygen demand. It is most beneficial when the patient who presents with CHF is also hypertensive. It is administered sublingually, intravenously, or transdermally

A 27-year-old man who is otherwise healthy presents to the ED with a laceration on his thumb that he sustained while cutting a bagel. You irrigate and repair the wound and are about to discharge the patient when he asks you if he can receive an ECG. It is not busy in the ED so you perform the ECG, as seen below. Which of the following is the most appropriate next step in management?

The patient’s ECG shows a sinus rhythm at a rate of 70 with first-degree heart block. First-degree heart block is defined as prolonged conduction of atrial impulses without the loss of any impulse. On an ECG this translates to a PR interval greater than 200 milliseconds with a narrow QRS complex (< 120 milliseconds). First-degree heart block is often a normal variant without clinical significance, occurring in 1% to 2% of healthy young adults. This variant requires no specific treatment.

A 61-year-old woman with a history of diabetes and hypertension is brought to the ED by her daughter. The patient states that she started feeling short of breath approximately 12 hours ago and then noticed a tingling sensation in the middle of her chest and became diaphoretic. An ECG reveals ST depression in leads II, III, and aVF. You believe that the patient had a non–ST-elevation MI (NSTEMI). Which of the following cardiac markers begins to rise within 3 to 6 hours of chest pain onset, peaks at 12 to 24 hours, and returns to baseline in 7 to 10 days?

Serum cardiac markers are used to confirm or exclude myocardial cell death and are considered the gold standard for the diagnosis of MI. While there are many markers currently used; the most sensitive and specific markers are troponin I and T. A rise in these levels, as seen in the figure, is diagnostic for an acute MI. Troponin levels rise within 3 to 6 hours of chest pain onset, peak at 12 to 24 hours, and remain elevated for 7 to 10 days.

A 27-year-old man complains of chest palpitations and lightheadedness for the past hour. He has no past medical history and is not taking any medications. He drinks a beer occasionally on the weekend and does not smoke cigarettes. His HR is 180 beats per minute, BP is 110/65 mm Hg, and oxygen saturation is 99% on room air. An ECG reveals an HR of 180 beats per minute with a QRS complex of 90 milliseconds with a regular rhythm. There are no discernable P waves. Which of the following is the most appropriate medication to treat this dysrhythmia?

Narrow-complex tachycardias are defined as rhythms with a QRS complex duration less than 100 milliseconds and a ventricular rate greater than 100 beats per minute. Although virtually all narrow-complex tachydysrhythmias originate from a focus above the ventricles, the term supraventricular tachycardia (SVT) is conventionally used to denote those rhythms aside from sinus tachycardia, atrial tachycardia, atrial fibrillation, and atrial flutter (eg, atrioventricular nodal reentry tachycardia and atrioventricular reentry tachycardia). Adenosine, an ultrashort-acting AV nodal blocking agent, is typically used to treat SVTs. Because it is so fast-acting, it must be delivered through a large vein (eg, the antecubital fossa) with a rapid intravenous fluid bolus. In addition to adenosine, maneuvers that increase vagal tone have been shown to slow conduction through the AV node. Some of these maneuvers include carotid sinus massage, Valsalva maneuver, and facial immersion in cold water.

The Quizzes about Chest Pain and Cardiac Dysrhythmias – Part 1 (20 test)
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