MSD MANUAL PROFESSIONALS////QUIZZES

Cardiovascular Disorders

Quiz: Angina Pectoris
Question 1 of 3  
Angina pectoris is usually described as chest discomfort rather than as chest “pain.” The symptoms of angina pectoris may be a vague, barely troublesome ache or may rapidly become a severe, intense precordial crushing sensation. Although the location of the discomfort varies, it is most commonly felt at which of the following locations?
 

• A.
  Beneath the sternum
  
• B.
  Down the inside of the right arm
   
  
• C.
  In the throat, jaws, and teeth
  
• D.
  In the upper abdomen
  
   
  

[وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط]

You're right!

A.
Beneath the sternum

Explanation
Answer: A: Beneath the sternum. This is the most common location of the discomfort of angina pectoris. Choices B, C, and D: These are other locations where the discomfort of angina pectoris may be felt, but they are not as common as beneath the sternum.


Angina pectoris is a clinical syndrome of precordial discomfort or pressure due to transient myocardial ischemia without infarction. It is typically precipitated by exertion or psychologic stress and relieved by rest or sublingual nitroglycerin. Diagnosis is by symptoms, electrocardiography, and myocardial imaging. Treatment may include antiplatelet medications, nitrates, beta-blockers, calcium channel blockers, angiotensin-converting enzyme inhibitors, statins, and coronary angioplasty or coronary artery bypass graft surgery.

Etiology of Angina Pectoris

Angina pectoris occurs when

• 
  Cardiac workload and resultant myocardial oxygen demand exceed the ability of coronary arteries to supply an adequate amount of oxygenated blood
  

Such imbalance between supply and demand can occur when the arteries are narrowed. Narrowing usually results from

• 
  Coronary artery [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط]
  

Narrowing of the coronary arteries can also result from

• 
  [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط]
  
• 
  Coronary artery embolism (rare)
  

Acute coronary thrombosis can cause angina if obstruction is partial or transient, but it usually causes [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط] (MI).

Because myocardial oxygen demand is determined mainly by heart rate, systolic wall tension, and contractility, narrowing of a coronary artery typically results in angina that occurs during exertion and is relieved by rest.

In addition to exertion, cardiac workload can be increased by disorders such as [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط], [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط], [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط], or [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط]. In such cases, angina can result whether atherosclerosis is present or not. These disorders can also decrease relative myocardial perfusion because myocardial mass is increased (causing decreased diastolic flow).

A decreased oxygen supply, as in severe anemia or hypoxia, can precipitate or aggravate angina.

Pathophysiology of Angina Pectoris

Angina may be

• 
  Stable
  
• 
  Unstable
  

In stable angina, the relationship between workload or demand and ischemia is usually relatively predictable.

[وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط] is clinically worsening angina (eg, angina at rest or with increasing frequency and/or intensity of episodes).

Atherosclerotic arterial narrowing is not entirely fixed; it varies with the normal fluctuations in arterial tone that occur in all people. Thus, more people have angina in the morning, when arterial tone is relatively high. Also, abnormal endothelial function may contribute to variations in arterial tone; eg, in endothelium damaged by atheromas, stress of a catecholamine surge causes vasoconstriction rather than dilation (normal response).

As the myocardium becomes ischemic, coronary sinus blood pH falls, cellular potassium is lost, lactate accumulates, ECG abnormalities appear, and ventricular function (both systolic and diastolic) deteriorates. Left ventricular (LV) diastolic pressure usually increases during angina, sometimes inducing pulmonary congestion and [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط]. The exact mechanism by which ischemia causes discomfort is unclear but may involve nerve stimulation by hypoxic metabolites.

Symptoms and Signs of Angina Pectoris

Angina may be a vague, barely troublesome ache or may rapidly become a severe, intense precordial crushing sensation. It is rarely described as "pain." Discomfort is most commonly felt beneath the sternum, although location varies. Discomfort may radiate to the left shoulder and down the inside of the left arm, even to the fingers; straight through to the back; into the throat, jaws, and teeth; and, occasionally, down the inside of the right arm. It may also be felt in the upper abdomen. The discomfort of angina is never above the ears or below the umbilicus.

Atypical angina, with bloating, gas, abdominal distress, or burning or tenderness in the back, shoulders, arms or jaw, may occur in some patients and is more common among females. These patients often ascribe symptoms to indigestion; belching may even relieve the symptoms. Other patients have dyspnea due to the sharp, reversible increase in LV filling pressure that often accompanies ischemia. Frequently, the patient’s description is imprecise, and whether the problem is angina, dyspnea, or both may be difficult to determine. Because ischemic symptoms require a minute or more to resolve, brief, fleeting sensations rarely represent angina.

Between and even during attacks of angina, physical findings may be normal. However, during the attack, heart rate may increase modestly, blood pressure (BP) is often elevated, heart sounds become more distant, and the apical impulse is more diffuse. The second heart sound (S2) may become paradoxical because LV ejection is more prolonged during an ischemic attack. A fourth heart sound (S4) is common, and a third heart sound (S3) may develop. A mid or late systolic apical murmur, shrill or blowing—but not especially loud—may occur if ischemia causes localized papillary muscle dysfunction, causing mitral regurgitation.

Angina pectoris is typically triggered by exertion or strong emotion, usually persists no more than a few minutes, and subsides with rest. Response to exertion is usually predictable, but in some patients, exercise that is tolerated one day may precipitate angina the next because of variations in arterial tone. Symptoms are exaggerated when exertion follows a meal or occurs in cold weather; walking into the wind or first contact with cold air after leaving a warm room may precipitate an attack. Symptom severity is often classified by the degree of exertion resulting in angina (see table Canadian Cardiovascular Classification System for Angina Pectoris ).

Table

Quiz: Atrial Fibrillation
Question 1 of 3  
Which of the following findings is most likely to distinguish other irregular rhythms from atrial fibrillation on ECG? 

• A.
  Absence of P waves
  
• B.
  Discrete P or flutter waves
  
• C.
  f waves between QRS complexes  
  
• D.
  
• Irregularly irregular R-R intervals
  

You're right!
 
B.
Discrete P or flutter waves

Explanation
Answer: B: Discrete P or flutter waves, which can sometimes be made more visible with vagal maneuvers. A, C, and D are ECG findings consistent with a diagnosis of atrial fibrillation.

Atrial fibrillation is a rapid, irregularly irregular atrial rhythm. Symptoms include palpitations and sometimes weakness, effort intolerance, dyspnea, and presyncope. Atrial thrombi may form, causing a significant risk of embolic stroke. Diagnosis is by electrocardiography. Treatment involves rate control with drugs, prevention of thromboembolism with anticoagulation, and sometimes conversion to sinus rhythm by drugs or cardioversion.

Atrial fibrillation has been attributed to multiple wavelets with chaotic reentry within the atria. However, in many cases, firing of an ectopic focus within venous structures adjacent to the atria (usually the pulmonary veins) is responsible for initiation and perhaps maintenance of atrial fibrillation. In atrial fibrillation, the atria do not contract, and the atrioventricular (AV) conduction system is bombarded with many electrical stimuli, causing inconsistent impulse transmission and an irregularly irregular ventricular rate, which is usually in the tachycardia rate range.

Atrial fibrillation is one of the most common arrhythmias, affecting between 3 and 6 million adults in the US. Men and White people are more likely to have atrial fibrillation than women and Black people. Prevalence increases with age; almost 10% of people > 80 years are affected. Atrial fibrillation tends to occur in patients with an underlying heart disorder.

Complications of atrial fibrillation

The absent atrial contractions predispose to thrombus formation; annual risk of cerebrovascular embolic events is about 7%. Risk of [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط] is higher in older patients and in patients with a rheumatic valvular disorder, mechanical heart valve, hyperthyroidism, hypertension, diabetes, left ventricular systolic dysfunction, or previous thromboembolic events. Systemic emboli can also cause malfunction or necrosis of other organs (eg, heart, kidneys, gastrointestinal tract, eyes) or a limb.

Atrial fibrillation also may impair cardiac output; loss of atrial contraction can lower cardiac output at normal heart rate by about 10%. Such a decrease is usually well tolerated except when the ventricular rate becomes too fast (eg, > 140 beats/minute), or when patients have borderline or low cardiac output to begin with. In such cases, [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط] may develop.

Etiology of Atrial Fibrillation

The most common causes of atrial fibrillation are

• 
  [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط]
  
• 
  [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط]
  
• 
  [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط]
  
• 
  Valvular heart disorders: [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط], [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط], [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط]
  
• 
  [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط]
  
• 
  Binge alcohol drinking (holiday heart)
  

Less common causes of atrial fibrillation include

• 
  [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط]
  
• 
  [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط] and other congenital heart defects
  
• 
  [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط]
  
• 
  [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط]
  
• 
  [وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط]
  

Lone atrial fibrillation is atrial fibrillation without an identifiable cause in patients < 60 years.

Quiz: Cardiac Auscultation
Question 1 of 3  
Auscultation of the heart requires excellent hearing to be able to distinguish subtle differences in pitch and timing of heart sounds, murmurs, and rubs. Systolic heart sounds include the first heart sound (S1) and clicks. Which of the following conditions is most likely indicated when S1 is soft or absent?

• A.
  Mitral regurgitation
  
• B.
  Mitral stenosis
  
• C.
  Pulmonary hypertension
  
• D.
  
• Pulmonic stenosis
  

a better answer.

A.
Mitral regurgitation

• 
  
  Explanation
  Answer: A: Mitral regurgitation. When S1 is soft or absent during cardiac auscultation, mitral regurgitation is indicated. This is due to valve leaflet sclerosis and rigidity. Choice B: When S1 is loud, mitral stenosis is indicated. Choice C and D: A click is higher pitched and has a briefer duration than S1. A click that occurs in early systole is heard in patients with severe pulmonary hypertension or pulmonic stenosis
  
  
• .https://www.msdmanuals.com/professional/cardiovascular-disorders/approach-to-the-cardiac-patient/cardiac-auscultation
  

Quiz: Deep Vein Thrombosis (DVT)
Question 1 of 3  
About 50% of patients with deep vein thrombosis (DVT) also have which of the following conditions?

• A.
  Occult cancer
  
• B.
  Occult pulmonary emboli
  
• C.
  Protein C deficiency
  
• D.
  Sickle cell anemia
  

   You're right!
B.
Occult pulmonary emboli

Explanation
Answer: B. About 50% of patients with DVT have occult pulmonary emboli, and at least 30% of patients with PE have demonstrable DVT. A: Occult cancers may be present in patients with apparently idiopathic DVT, but extensive evaluation of patients for tumors is not recommended unless patients have major risk factors for cancer or symptoms suggestive of an occult cancer. Choices C and D are risk factors for DVT.

[وحدهم المديرون لديهم صلاحيات معاينة هذا الرابط]