Clinical Aerospace Medicine Flashcards
Cardiac arrhythmias which result in syncope can be catastrophic in the aviation setting. Which of the following can lead to atrial sinus arrest and syncope?
a) positive pressure breathing
b) The M-1 maneuver
c) an attempt to stop hyperventilation by deep breath holding.
d) all of the above.
d) All of the above. Positive pressure breathing of 100% oxygen is used as an emergency means of maintaining adequate arterial oxygen saturation in the event of loss of cabin pressurization at or above 40,000 feet. The M-1 maneuver, a continuous forced exhalation through a partially closed glottis, is used to overcome undesirable effects during exposure to G forces. Breath holding likewise can cause sinus arrest. Each of these can increase vagal stimulation, atrial sinus arrest, and syncope in sensitive individuals.
In aircrew who suffer a spontaneous pneumothorax:
a) the treatment of choice is pleurectomy
b) the treatment of choice is chemical pleurodesis
c) the recurrence rate is 30% after a first pneumothorax
d) the condition may manifest only when airborne
e) A, C, and D are correct
e) The aeromedical importance of a spontaneous pneumothorax is related to the tendency to recur: at a rate of 30% after the first event, and rising to 80% after a third. Definitive treatment is therefore necessary before aircrew with the condition may be allowed to resume flying. Unlike pleurectomy, chemical pleurodesis is associated with significant failure rate and morbidity.
Studies of miniature swine exposed acutely to G stress up to levels of +9 Gz for 45 seconds have consistently revealed subendocardial hemorrhage and cardiomyopathy. The cardiomyopathies include myofibrillar degeneration, translocation, and clumping of mitochondria and necrosis of cardiac myocytes. It is believed that these same cardiomyopathies occur in humans who are exposed to similar G forces.
A) True
B) False
B. False. Although the swine studies revealed these pathologies at operational G levels, a follow-on study in humans using all available clinical monitoring techniques did not reveal similar conditions.
Syncope is an aeromedical problem that often confronts the flight surgeon. Which of the following signs and symptoms may be seen with a syncopal attack?
a) Generalized muscle weakness
b) Impairment of consciousness
c) Occurs while lying down on occasion
d) Brief duration
e) May have assoiciated clonic jerks
A, B, D, E
Myocardial infarction and acute pericarditis are sometimes difficult to distinguish clinically. Which of the following laboratory findings often will be found in acute pericarditis?
- Leukocytosis and increased sedimentation rate
- Chest xray evidence of increased cardiac size
- Pleural effusions and/or infiltrates on chest xray
- Electrocardiographic changes in the ST segment
- Subsequent T-wave inversion days to weeks later
- Elevation of serum enzymes, SGOT, LDH
All the above
How long is the usual clinical course of acute pericarditis, including common sequelae?
1-2 months
Angina is a symptom complex attributed to transient and reversible myocardial ischemia, often caused by underlying coronary atherosclerosis. The ECG is normal in what percentage of patients with angina pectoris?
50-75%
Myocarditis is frequently unrecognized either because of its subclinical nature or because of the severity of associated symptoms. Complications of myocarditis of aeromedical interest include congestive heart failure, hypoxia, arrhythmias, and sudden death. Causes of myocarditis include viral, bacterial, rickettsial, parasitic, fungal, spirochetal, and secondary reactions to systemic processes such as hypersensitivity reactions or connective tissues diseases. What is the incidence of myocarditis as determined by autopsy data?
3-9%
What are the five major risk factors associated with the development of atherosclerosis?
Hypertension, smoking, diabetes, family history, and elevated cholesterol
Which of the following foods has the highest cholesterol content (in mg)?
a) Sausage
b) Lard
c) Shrimp
d) Lobster
C) Shrimp
Recent investigations have indicated that myocardial sarcoidosis may be much more common that heretofore believed. As a flight surgeon, which of the following statements is true and is of particular aeromedical significance?
a) myocardial sarcoidosis, although not a rare condition, is usually benign in that only normal variants such as first degree AV block and wandering pacemaker have been detected.
b) arrhythmias such as ventricular tachycardia and supraventricular tachycardia can occur causing incapacitation or sudden death.
c) myocardial sarcoidosis causes incapacitation arrhythmias but almost always in older patients (over age 60).
d) myocardial sarcoidosis in usually a serious condition but almost all patients have significant, detectable pulmonary disease well before cardiac involvement.
b) Arrhythmias such as ventricular tachycardia and supraventricular tachycardia can occur causing incapacitation or sudden death.
In recent years, researchers in aerospace medicine have concluded that electrocardiograms, once thought to be abnormal, are actually normal variants. All of the following are usually considered normal variants EXCEPT:
a) first degree AV block
b) Mobitz type II block
c) premature atrial contractions
d) premature ventricular contractions
e) All of the above are normal variants
b) Mobitz type II is a heart block. It is NOT a normal variant.
Many young men undergoing aircrew examinations have cardiac murmurs that do not indicate organic heart disease. Which one of the following findings suggests the presence of organic heart disease?
a) a grade II/VI systolic murmur detected only in the left lateral position.
b) a grade II/VI systolic murmur detected only in the left lateral position present only after exercise.
c) a grade I/VI diastolic murmur which becomes grade II/VI with exercise.
d) a grade I-II/VI systolic murmur heard intermittently by different physicians over the past 3 years.
e) a grade I/VI systolic murmur at the base of the heart, heard at the termination of treadmill exercise testing.
c) A grade I/VI diastolic murmur which becomes grade II/VI with exercise. As a general rule, the occurrence of any diastolic murmur should be considered secondary to organic heart disease until proven otherwise.
Which cardiac disorder would be more directly related to the development of acute right heart failure in the presence of hypoxia?
a) Wenckeback phenomenon
b) Mitral insufficiency
c) Mitral stenosis
d) RBBB
c) Mitral stenosis due to an increase in right heart pressures.
Undetectable patent foramen ovale probably exists in 25-30% of the population and poses no threat to the health of the flying population with the possible exception of which aerospace medical problem?
a) high -Gy force
b) hyperventilation
c) decompression sickness
d) severe active airsickness
c) Decompression sickness
An A-V conduction defect characterized by a progressively increasing PR interval before a QRS complex is dropped could be termed as a(n):
a) Wenckebach phenomenon
b) 2nd degree heart block
c) Mobitz Type I
d) All of the above
d) All of the above
Which of the following valvular disorders would likely result in a reduced tolerance to +Gz forces?
a) Aortic insufficiency
b) Mitral stenosis
c) Aortic stenosis
d) Mitral insufficiency
a) Aortic insufficiency
Of the following electrical conductive abnormalities of the heart, which would most likely be associated with severe or extensive coronary artery disease and other cardiac disorders?
a) RBBB
b) LBBB
c) 1 degree AV block
d) Mobitz Type I
b) LBBB
A the time of physical examination of a young adult male, you detect an apical systolic heart murmur. Further studies confirm your presumptive diagnosis of mild mitral insufficiency. Your advice should include which of the following?
a) Prevention of subacute bacterial endocarditis and recurrent rheumatic fever.
b) Restriction against aviation activities as a pilot due to the potential hemodynamic impairment caused by accelerative forces (G forces).
c) Explanation of the requirements for appropriate medical and administrative following of his condition, but little limitations of his activities.
d) a and c above.
d) A and C above.
Functional cardiac murmurs are often heard at the time of physical examination for flying. As a general rule:
a) low intensity systolic murmurs, which can be heart only in the left lateral position over the base of the heart, may be considered physiologic.
b) the occurrence of a low grade diastolic murmur after exercise should be considered physiologic.
c) the occurrence of a low grade systolic murmur after exercise should be considered as secondary to organic heart disease.
d) All of the above.
a) low intensity systolic murmurs, which can be heard only in the left lateral position over the base of the heart, may be considered physiologic.
One of the most common electrocardiographic interpretations that must be made in evaluating aircrew members involve nonspecific T-waves changes. These may be indicative of which of the following?
a) Previous myocardial infarctions
b) Failure of the subjects to have properly maintained the fasting basal rate.
c) Anxiety at the time of the electrocardiogram.
d) All of the above.
d) All of the above- Non-specific T wave changes can be caused by eating, smoking, drinking, apprehension, hyperventilation.
Cardiac arrhythmias which result in syncope can be catastrophic in the aviation setting. Which of the following can lead to atrial sinus arrest and syncope?
a) positive pressure breathing
b) The M-1 maneuver
c) An attempt to stop hyperventilation by deep breath holding
d) All of the above
d) All of the above
The appearance of frequent premature ventricular contractions in an asymptomatic pilot with no previous history of PVC’s:
a) should result in permanent grounding
b) should result in immediate grounding and a search for etiologic factors, including presence of cardiovascular disease.
c) are of no consequence if they occur at a frequency of less than five per minute.
d) are of no consequence as long as they are unifocal.
e) should result in permanent grounding if they are multifocal
b) should result in immediate grounding and a search for etiologic factors, including presence of cardiovascular disease.
Meniere’s disease is characterized by:
a) vertigo which lasts a few seconds
b) vertigo which lasts a few days, decreasing in intensity from onset
c) an ill-defined feeling of imbalance
d) vertigo which lasts for hours
d) Vertigo which lasts for hours (1 to 24 hours) with most cases being 3-4 hours.