Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_2892_Библиотеки_им_академика_М_И_Перельмана
.pdf
470 CASE FILES: FAMILY MEDICINE
https://t.me/medicina_free
Schuckit MA. Alcohol and alcohol use disorders. In: Jameson J, Fauci AS, Kasper DL, Hauser SL,
Longo DL, Loscalzo J, eds. Harrison’s Principles of Internal Medicine. 20th ed. New York, NY:
McGraw Hill; 2018: Chap. 445. http://accessmedicine.mhmedical.com/content.aspx?bookid=
2129§ionid=192534023. Accessed January 21, 2019.
Substance Abuse and Mental Health Services Administration. (2019). Key Substance Use and Mental
(HHS Publication No. SMA 19-5068, NSDUH Series H-53). Rockville, MD: Center for Behavioral Health Statistics and Quality, Substance Abuse and Mental Health Services Administration.
September 2018. https://www.samhsa.gov/data/sites/default/files/cbhsq-reports/NSDUH
NationalFindingsReport2018/NSDUHNationalFindingsReport2018.pdf. Accessed May 26, 2020.
Unhealthy Alcohol Use in Adolescents and Adults: Screening and Behavioral Counseling Interventions.
US Preventive Services Task Force. November 2018. https://www.uspreventiveservicestaskforce
.org/uspstf/recommendation/unhealthy-alcohol-use-in-adolescents-and-adults-screening-andbehavioral-counseling-interventions. Accessed August 20, 2019.
Winslow BT, Onysko M, Hebert M. Medications for alcohol use disorder. Am Fam Physician.
2016;93(6):457-465.
Zoorob RJ, Grubb RJ, Gonzalez SJ, Kowalchuk AA. Using alcohol screening and brief intervention to
address patients’ risky drinking. Fam Pract Manag. 2017;24(3):12-16.
CASE 42
https://t.me/medicina_free
A 35-year-old woman presents to your office complaining of skipped or “irregular
heartbeats” for the past few weeks. At first, she attributed her symptoms to jobrelated stress and thought they would disappear. Instead, the skipped beats have
increased in frequency to twice a day, lasting up to 2 minutes per episode. Her
father, who has coronary heart disease, urged her to see a doctor. She denies
chest pain, shortness of breath, or presyncopal symptoms. She drinks two cups of
caffeinated coffee per day, does not smoke, and rarely drinks alcohol. She recently
tried some over-the-counter diet pills to lose weight but stopped taking them
when her symptoms became more frequent. On examination, her temperature
is 98.6 °F (37 °C), blood pressure is 130/85 mm Hg, heart rate is 92 beats/min,
respiratory rate is 16 breaths/min, and body mass index (BMI) is 27 kg/m2. Neck
examination is without thyromegaly, nodule, or mass and without jugular venous
distention or bruit. Lung examination is bilaterally clear to auscultation. Cardiac
examination reveals regular rate and rhythm with normal S1 and S2. A midsystolic
click followed by a late systolic crescendo murmur is heard at the fifth intercostal
space at the midclavicular line. Abdominal examination is unremarkable.
Examination of the extremities reveals palpable symmetric distal pulses in all four
extremities. Neurologic examination reveals no resting tremor, and reflexes are
within normal limits.
▶ What is the most likely diagnosis?
▶ What is the most appropriate initial diagnostic step?
▶ What is the most appropriate initial step in therapy?
472 CASE FILES: FAMILY MEDICINE
https://t.me/medicina_free
ANSWERS TO CASE 42:
Palpitations
Summary: A 35-year-old woman presents with
Palpitations for weeks that have increased in frequency
Symptoms that are not associated with chest pain, syncope, dyspnea, or dizziness
No pertinent past medical history
Potential triggers of caffeine consumption, diet pill use, and stress
A midsystolic click followed by a late systolic crescendo murmur
Family history of coronary heart disease in her father
Most likely diagnosis: Mitral valve prolapse syndrome.
Initial diagnostic step: Obtain 12-lead electrocardiogram (ECG) and echocardiogram.
Initial step in therapy: Restrict caffeine and alcohol; eliminate any amphetamine-
based stimulants and/or diuretics; keep a diary of symptoms or possible triggers;
follow up with patient to discuss results; monitor for complications; and consider
antibiotic prophylaxis for future dental procedures.
ANALYSIS
Objectives
1. Define palpitations. (EPA 1, 12)
2. Identify benign cardiac rhythms and those associated with sudden cardiac
death. (EPA 1, 10)
3. Identify the most common structural heart diseases associated with sudden
cardiac death. (EPA 10)
4. Develop a rational approach that considers cardiac and noncardiac causes for
palpitations. (EPA 2, 3)
Considerations
An otherwise healthy 35-year-old woman gives a history of frequent palpitations
without associated dizziness, syncope, or chest pain. We are given clues to noncardiac factors that may contribute to her symptoms, including caffeine consumption,
use of diet pills, and job-related stress. Obtaining a clear family history is important because some arrhythmias and structural heart diseases (eg, hypertrophic cardiomyopathy) can run in families. A family history of premature cardiac death or
unexplained sudden death may suggest such an inheritance.
A mid-systolic click associated with or without a late systolic murmur suggests
the presence of mitral valve prolapse (MVP). Usually asymptomatic, it is the most
common valvular heart defect in the United States, occurring in 3% to 6% of the
population. While many are asymptomatic, patients may present with palpitations,
fatigue, chest discomfort, and dyspnea. This symptom complex is defined as mitral
SECTION II: CLINICAL CASES 473
https://t.me/medicina_free
valve prolapse syndrome. These patients may also present with panic attacks. Two
percent of patients with MVP will have complications, including mitral regurgitation, atrial fibrillation (AF; if the left atrium becomes enlarged), systolic heart
failure, pulmonary hypertension, or infective endocarditis.
Mitral valve prolapse is also associated with Marfan syndrome, as these patients
often have aortic root dilations and are at risk for aortic arch aneurysm rupture.
Marfan syndrome should be suspected in patients who are tall and thin and have
scoliosis; pectus excavatum; long, thin digits (arachnodactyly); a high-arched palate; and an arm wingspan exceeding their height.
APPROACH TO:
Palpitations
DEFINITIONS
ARRHYTHMIA: Primary rhythm disturbances that represent a change from the
normal sequence of electrical impulses within the heart.
PALPITATIONS: A common subjective sensation of unduly strong, slow, rapid,
or irregular heartbeats that may be related to a cardiac arrhythmia. The sensation
may last seconds, minutes, hours, or days and is often intermittent and not clinically concerning.
CLINICAL APPROACH
Pathophysiology
Palpitations are a very common outpatient complaint, comprising as many as 16%
of visits to primary care physicians (Table 42–1). Approximately 40% of patients
complaining of palpitations have an underlying primary rhythm disturbance. An
underlying mental health problem (eg, anxiety, panic disorder) is attributable in
31% of symptomatic patients. Less common etiologies include drugs and alcohol
(6%), structural problems within the heart (3%), or noncardiac causes (4%), and
16% are idiopathic. Palpitations associated with syncope, occurring at work or
physical activity, affecting sleep, or in the context of known heart disease are more
likely due to a cardiac cause. Clinicians are commonly alerted to cardiac palpitations because they may increase the risk of sudden cardiac death.
Cardiac Causes
Benign arrhythmias account for the majority of cases of palpitations. Sinus tachycardia, sinus bradycardia, premature atrial contractions, and premature ventricular
contractions (PVCs) represent the most common etiology of benign palpitations,
while sinus tachycardia and bradycardia are also common benign dysrhythmias
that can manifest as palpitations.
Premature Ventricular Contractions. PVCs occurring at rest and disappearing
with exercise are usually benign. They are commonly seen in athletes and require
474 CASE FILES: FAMILY MEDICINE
https://t.me/medicina_free
Table 42–1 • CARDIAC AND NONCARDIAC CAUSES OF PALPITATIONS
Arrhythmias Atrial fibrillation/flutter
AV reentrant tachycardia
Congenital arrhythmias (ie, Wolff-Parkinson-White, Brugada,
long QT syndromes)
Multifocal atrial tachycardia
Paroxysmal supraventricular tachycardia
Premature atrial contractions (PAC) (most common)
Premature ventricular contractions (PVCs)
Sinus bradycardia
Sick sinus syndrome
Sinus tachycardia
Ventricular fibrillation
Ventricular tachycardia (VT)
Medications Anticholinergics (ie, nasal decongestants)
Beta-blocker withdrawal
Inhalers (ie, short acting beta-agonists)
Sympathomimetics (ie, epinephrine)
Vasodilators (ie, nitrates)
Metabolic derangement Electrolyte abnormalities
Hyper-/hypothyroidism
Hypoglycemia
Pheochromocytoma
Other substances Alcohol
Amphetamines
Cocaine
Marijuana
Nicotine
Other noncardiac Anemia
Exercise
Fever
Hypovolemia
Stress
Vasovagal syncope
Paget disease of bone
Pregnancy
Pulmonary disease
Psychiatric disorders Generalized anxiety disorder
Other anxiety disorders
Panic disorder
Somatization disorder
Structural heart disease Cardiomyopathy (ie, hypertrophic)
Tumor (ie, atrial myxoma)
Valvular disease (ie, MVP)
SECTION II: CLINICAL CASES 475
https://t.me/medicina_free
no investigation. PVCs in the presence of known cardiac disease, metabolic disease, or worrisome symptoms (eg, syncope) require appropriate investigation due
to increased risk of fatal arrhythmias, including ventricular tachycardia (VT) or
ventricular fibrillation.
Supraventricular Tachycardia. Supraventricular tachycardia (SVT) refers to any
tachycardia that is not of ventricular origin. This definition includes sinus tachycardia, which can be a physiologic reaction to conditions like stress, fever, infection, or
hyperthyroidism. Most SVTs are paroxysmal and have a sudden, almost immediate onset and regular rhythm. A person experiencing paroxysmal SVTs (PSVT)
may feel their heart rate go from 60 to 200 beats/min instantaneously. PSVTs are
most commonly atrioventricular (AV) nodal reentry tachycardias or part of WolffParkinson-White (WPW) syndrome. WPW syndrome is caused by an accessory
track that bypasses the AV node and conducts electrical impulses between the atria
and ventricles. The classic ECG finding is a slurred upstroke of the QRS complex
known as a “delta wave.” WPW increases susceptibility to dangerous arrhythmias
and can lead to sudden cardiac death. It can be treated by catheter ablation of the
accessory track.
Prolonged QT Interval. Prolongation of the QT interval is another common finding that predisposes to cardiac events. Prolonged QT interval has been linked to
a wide variety of medications, including macrolide antibiotics, antiemetics, antiarrhythmics, antipsychotics, and antidepressants. Prolonged QT interval is defined
1
as QT
greater than 470 milliseconds in men or 480 milliseconds in women. Any
C
patient with a QT interval greater than 500 milliseconds is at increased risk for dangerous arrhythmias.
QTC is defined as measured QT interval corrected for heart rate:
√RR interval (in msec)
A variety of less common genetic arrhythmias may present in young adults or even
children. While most cases of long QT interval are acquired, long QT interval
syndrome is a rare genetic cause, most often inherited in an autosomal dominant
pattern. Patients may present with either palpitations or syncope and typically have
a family history of syncope or sudden cardiac death.
Noncardiac Causes
Psychiatric Causes. Psychiatric causes should be considered in the differential
diagnosis for palpitations and may be overlooked if not screened for in the initial
history. Panic disorder is more common in women of childbearing age. Patients
with panic attacks commonly present with complaints of palpitations, chest pain,
and shortness of breath. They will report brief episodes of overwhelming panic
or a sense of impending doom associated with tachycardia, dyspnea, or dizziness. Still, these complaints merit a formal cardiac workup and risk stratification.
Criteria for panic disorder are often comorbid with SVT, and women are more
likely to be misdiagnosed with an anxiety disorder when presenting with a cardiac event.
QT (in msec)
QTC =
476 CASE FILES: FAMILY MEDICINE
https://t.me/medicina_free
Medications and Substances. Numerous medications and substances may contribute to palpitations, including alcohol, nicotine, caffeine (especially energy drinks),
and illicit drugs (eg, cocaine). A careful medication review and inquiry about any
over-the-counter medications, herbs, or supplements are important to an evaluation of palpitations.
Structural Causes. Structural causes of palpitations include cardiomyopathy,
atrial or ventricular septal defects, congenital heart disease, pericarditis, valvular
disease (eg, MVP, aortic stenosis, aortic insufficiency), and heart failure. The presence of restrictive, hypertrophic, or dilated cardiomyopathies may lead to sudden
cardiac death. Hypertrophic obstructive cardiomyopathy (HCM) is the most com-
mon cause of sudden cardiac death in adolescents in the United States but is often
not detected on routine physical examination (Case 29). Echocardiography demonstrating a thickened intraventricular septum with outlet obstruction remains the
gold standard for diagnosis; however, current evidence does not support routine
echocardiography screening in athletes.
Clinical Presentation
History and Physical Examination. The patient’s age at onset of palpitations is
important to note, as an age older than 50 years is associated with greater risk of
coronary artery disease. Palpitations associated with syncope are usually pathologic, so hospitalization with cardiac monitoring and cardiology evaluation should
be considered. The clinical examination should focus on vital signs (blood pressure
and heart rate), including orthostatic readings. The neck should be examined for
abnormalities, including thyroid enlargement or nodule or carotid bruit. The presence of resting tremor or brisk reflexes may suggest hyperthyroidism. The cardiac
examination should evaluate potential murmurs and point of maximum impulse
since displacement may suggest cardiomegaly. Heart rate, rhythm, and extra sounds
should be documented.
Laboratory Values. Laboratory screening of all patients with new palpitations
should include a complete blood count, comprehensive metabolic panel, and thyroid-
stimulating hormone level. If a pheochromocytoma is suspected, plasma and/or
24-hour urine metanephrines evaluation is indicated.
Electrocardiogram. A 12-lead ECG is appropriate in all patients with palpitations,
even if they are symptom free during the provider encounter. The presence of left
ventricular hypertrophy, atrial enlargement, AV block, prior myocardial infarction,
and delta waves should trigger additional testing. Prolonged QT interval should
trigger a thorough review of medications, as well as consultation with a cardiologist. Other cardiac testing may be appropriate based on the history, examination,
and results of the initial evaluation. Ambulatory electrocardiographic rhythm monitoring can be accomplished for periods of 24 to 72 hours using a Holter monitor. A
cardiac event monitor can be worn by a patient for up to 30 days and might be useful
when the palpitations do not occur daily. The monitor is worn continuously and is
activated by the patient when palpitations are felt.
Imaging and Stress Testing. An echocardiogram can be useful in identifying
patients with suspected structural abnormalities of heart chambers or valves, which
could trigger heart rhythm disturbances. Cardiac examination findings consistent
SECTION II: CLINICAL CASES 477
https://t.me/medicina_free
with structural or valvular disease merit an echocardiogram; however, a normal
examination does not rule out these pathologies. Exercise stress testing in age- and
risk-appropriate patients may be important for identifying arrhythmias triggered
by exercise. This test may be of particular importance in patients with suspected
coronary artery disease. Anyone with suspected structural problems should be
evaluated by a surface echocardiogram prior to undergoing stress testing. Patients
with suspected HCM or severe aortic stenosis should avoid exercise stress testing.
Electrophysiology Testing. Finally, electrophysiology studies may be needed to re-
create rhythm disturbances and identify hyperactive foci and accessory tracts such
seen in WPW syndrome. These areas can subsequently be electrically ablated.
Treatment
The treatment of palpitations is dependent on the etiology. Reduction in exposure to triggers (eg, medications, excessive caffeine) may provide significant relief in
those with benign causes. Anxiety or panic disorder may be treated by a combination of pharmacologic and behavioral interventions. If structural cardiac disease is
suspected, referral to a cardiologist is indicated.
Symptomatic PSVT can often be terminated with vagal stimulation techniques.
Carotid sinus massage, Valsalva maneuver, and cold applications to the face (diver’s
reflex) can trigger vagus nerve stimulation, which may break an episode of SVT.
Intravenous adenosine is the treatment of choice to break SVT, while beta-blockers
or calcium channel blockers are used as first-line therapy for hemodynamically
stable SVT. Synchronized cardioversion is recommended in cases of acute SVT or
wide-complex tachycardia when the patient is hemodynamically unstable or when
medical therapy is either ineffective or contraindicated.
Ventricular Arrhythmias. Ventricular arrhythmias can be life threatening and
require immediate treatment. The most common cause of ventricular arrhythmias
is ischemia. VT may be reversed with antiarrhythmic therapy in hemodynamically
stable patients. Amiodarone can be used to convert VT to sinus rhythm or for
maintenance of sinus rhythm after electrical cardioversion. Patients with VT who
are unstable require immediate cardioversion. Ventricular fibrillation is imminently
fatal and requires defibrillation. An automatic implantable cardioverter-defibrillator
may be implanted in patients with a history of VT or with conditions that commonly result in ventricular arrhythmias, including advanced dilated cardiomyopathy, long QT syndrome, and HCM.
Atrial Fibrillation. Chronic AF should be treated with medication (commonly
beta-blockers or calcium channel blockers) to optimize a ventricular rate below
100 beats/min. Rhythm control (ie, conversion to sinus rhythm) has failed to
show superiority to rate control in a number of trials and may be associated with
an increased risk of hospitalization. In select patients, rhythm control may be
attempted by electrical cardioversion or antiarrhythmic drugs, including amiodarone. A transesophageal echocardiogram should be done prior to cardioversion in
order to rule out the presence of an atrial thrombus. Most patients with AF will
require anticoagulation because they are at an increased risk of embolic stroke from
blood clots that form in the cardiac atrium, in accordance with the CHADS2-VASC
risk calculation (www.chadsvasc.org).
478 CASE FILES: FAMILY MEDICINE
https://t.me/medicina_free
CASE CORRELATION
See Case 29 (Adolescent Health Maintenance).
COMPREHENSION QUESTIONS
42.1 A 35-year-old man presents to establish health care with a new family provider. He has no pertinent past medical or family history, and he does not
smoke or drink alcohol. When prompted, he states that he has noticed an
intermittent “fluttering” in his chest for the past 3 months that spontaneously
resolves. He has had increased stress at work and has been drinking six cups
of caffeinated coffee a day to complete his workload. He has not had time to
exercise, and his diet consists of what he can find in the office cafeteria. He
denies any history of anxiety. Which of the following is the most likely underlying etiology of his palpitations?
A. Excessive caffeine
B. Structural heart disease
C. Coronary artery disease
D. Primary rhythm disturbance
E. Work stress
42.2 A 42-year-old asymptomatic woman is being seen in the office for an annual
health maintenance examination. She is noted to have an abnormal finding
on ECG. Which of the following is an indication for referral to a cardiologist
or cardiac electrophysiologist?
A. PVCs on a resting ECG that resolve with exercise
B. Delta waves on an ECG
C. Isolated unifocal PVCs on exercise ECG
D. Sinus tachycardia
42.3 Which of the following patients should undergo an exercise stress test for
evaluation of palpitations?
A. A 60-year-old man with symptomatic PVCs but without syncope
B. A 35-year-old woman with hypertrophic cardiomyopathy seen on an
echocardiogram
C. A 32-year-old man who is tall and slender with pectus excavatum and a
midsystolic click on examination
D. A 68-year-old man with suspected aortic stenosis
SECTION II: CLINICAL CASES 479
https://t.me/medicina_free
42.4 A 16-year-old young man comes to your office for a sports physical. He plans
to try out for his high school football team but requires medical clearance.
He has no cardiovascular complaints, and his history is unremarkable except
for a family history of an uncle dying suddenly while jogging at age 25. His
physical examination is remarkable for a harsh systolic murmur loudest over
his left lower sternal border, which increases with the Valsalva maneuver. You
obtain an ECG, which shows left ventricular hypertrophy. Which of the following is the most appropriate next step in diagnostic evaluation?
A. An exercise stress test
B. An echocardiogram
C. A chest radiograph
D. A left-heart catheterization
E. Reassurance that he is cleared to play football
42.5 You are called to the bedside of a 55-year-old man who is hospitalized for the
evaluation of chest pain. When you arrive, you find the patient confused and
not answering questions. The nurse informs you that the patient was speaking coherently a few minutes ago. The patient’s pulse is 180 beats/min, his
systolic blood pressure is 60 mm Hg, and his diastolic blood pressure cannot
be measured. Telemetry reveals wide-complex tachycardia. Which of the following is the most appropriate next step in the management of this patient?
A. Adenosine
B. Cardiology consultation
C. Emergent cardioversion
D. Negative chronotropic agent
E. 12-lead ECG
ANSWERS
42.1 D. Primary rhythm disturbances are the most common cause of palpitations,
making up approximately 40% of cases. Other common causes include psychiatric etiologies (eg, anxiety, panic disorder); medications; metabolic causes
(eg, electrolytes, thyroid hormone imbalance); and structural heart disease
(answer B). Many cases of palpitations remain undiagnosed despite appropriate
evaluation. The other causes (answer A, excessive caffeine; answer C, coronary
artery disease; and answer E, work stress) are less common.
42.2 B. The presence of delta waves indicates WPW syndrome and the presence
of an accessory track that can be ablated by an electrophysiologist. Although
the patient is currently asymptomatic, the presence of this finding indicates a
high potential for a tachyarrhythmia. Answer A (PVCs on resting ECG) and
answer C (unifocal PVCs on exercise) are fairly common findings and not
indications for referral. A patient with answer D (sinus tachycardia) needs
to be further investigated regarding etiology but does not need a referral to a
cardiologist; for example, the patient may have anemia or hyperthyroidism.
Соседние файлы в папке Библиотека им академика М.И. Перельмана