Arrhythmia

Heart and Circulatory System—Arrhythmia (Irregular Heartbeat)

Arrythmia (Irregular Heartbeat)

Cardiac arrhythmias have a wide range of clinical significance, depending upon the type, location of origin, symptoms present, and the likelihood for sudden or subtle incapacitation. Arrhythmias that originate in the upper chambers of the heart, the atria, are referred to as "supraventricular" arrhythmias. The atria are the heart's pacemakers and also act as primers for the pump chambers, the ventricles. 
The most common atrial arrhythmia is atrial fibrillation, which is a rapid, irregular rhythm that can result in dizziness, shortness of breath, or loss of consciousness if the heart rate is too slow or fast.

Ventricular arrhythmias affect the lower pump chambers, the ventricles. Common ventricular arrhythmias include premature ventricular contractions (PVCs). These are fairly common in healthy people and can be brought on by a number of stimuli, including excessive caffeine consumption or stress. 
Ventricular tachycardia is a rapid heart rate with sudden onset. Symptoms of ventricular tachycardia include light-headedness, fainting, weakness, or mental confusion. This type of arrhythmia is often associated with underlying heart disease and requires good medical management.

The FAA grants special issuances for many types of arrhythmias.  Atrial fibrillation, atrial flutter, or ventricular/supraventricular arrhythmias that are not associated with underlying ischemic heart disease, cardiomyopathy (a disease of the heart muscle), or significant heart valve defect or outflow tract obstructions may be favorably considered for issuance of any class of medical certificate.

Atrial Fibrillation 

Atrial fibrillation is currently the most prevalent cardiac arrhythmia in the older U.S. population, increasing in prevalence from age 50 through the late 80s. The FAA reviews atrial fibrillation on the basis of additional risk factors.  Persons over age 75, or who have a history of stroke, transient ischemic attack, left ventricular dysfunction (impaired heart pump function) with an ejection fraction of less than 40 percent, coronary heart disease, mitral valve disease, or prosthetic heart valve, and hyperthyroidism are considered higher risks for medical certification and are less likely to be favorably reviewed. Lesser risks with a higher likelihood of certification include hypertension, diabetes mellitus, and age less than 65.

The arrhythmia can be categorized into three different subtypes: chronic or persistent, recurrent paroxysmal, and idiopathic or "lone." Lone atrial fibrillation is the most benign form and is defined as lone because it may have occurred only once, has resolved, and/or has no associated underlying organic heart or thyroid disease. 

Factors that might contribute to the development of lone atrial fibrillation include high caffeine intake, excessive alcohol consumption, medications, fatigue, respiratory disease, stress, and acute diarrhea and gastroenteritis leading to an imbalance of electrolytes.  

For special issuance medical certification, the FAA requires the following:

* if applying for first or second class medical, a radionuclide exercise perfusion scan is also required. 

Anticoagulation
Blood clots, or thrombus formation within the heart, are a risk with atrial fibrillation, and most people with this arrhythmia are on some form of anticoagulation, or blood thinning. Risk factors are based upon the CHADS 2 score that assigns a numeric risk for a history of congestive heart failure, hypertension, age greater than 75, diabetes, and stroke or TIA (transient ischemic attack). Each factor represents a score of 1 except for stroke/TIA that is a 2.  The higher the score, the higher the risk.

Persons under age 65 who have no other risk factors, the FAA accepts aspirin therapy alone for suitable anticoagulation.
If other risk factors are present, anticoagulation therapy must be part of the treatment plan, and can include warfarin (Coumadin), rivaroxaban (Xarelto) or apixaban (Eliquis). Xarelto or Eliquis do not require periodic blood testing, and may be preferable to obtain adequate anticoagulation.

Persons between age 65 and 75 with no risk factors may use aspirin, Coumadin, Xarelto, Pradaxa, or Eliquis. If over age 75, anticoagulation other than aspirin is required.

If on warfarin, the FAA requires at least 80% of the INR (International Normalized Ratio) readings be between 2.0-3.0. 

Holter monitor showing evidence of sinus pauses (a momentary disruption of the normal heart rhythm) of 3.0 seconds or longer during waking hours raises the risk of incapacitation to an unacceptable level, and the FAA will most likely deny certification. 
A resting heart rate of more than 100 beats per minute (rapid ventricular response) or episodes of heart rate greater than 120 with minimal exertion will also preclude certification for any class of medical certificate.

Most antiarrhythmic medications are acceptable for controlling the ventricular response or maintaining sinus rhythm if there are no adverse side effects and if symptoms are well controlled. Low doses of Cordarone (amiodarone) or Multaq (dronedarone) may be used in treating atrial fibrillation. A resting ECG will be required with these medications to identify presence of prolonged QT interval, which could be disqualifying if present.
The use of flecainide (Tambocor) is not considered acceptable in the presence of left ventricular dysfunction or recent myocardial infarction, but is otherwise an allowed medication. Other Class IC antiarrhythmics are also acceptable.

Murmurs

Murmurs are the sounds made by the opening and closing of the valves inside the heart that control blood flow between chambers.  Functional or physiological murmurs are normal sounds made by a normal heart and do not require an evaluation for medical certification.  In these cases, the AME can issue the certificate at the time of examination.  

Murmurs are graded on a scale of 6, and measured by the intensity of the heart sounds heard.  A grade 1/6 is indicative of a minimal, or benign, murmur that is barely perceptible and is usually considered a functional murmur.  

Murmurs of Grade 3 and higher should be evaluated prior to the FAA physical examination to determine if further documentation and/or treatment is needed.  The evaluation should include an M Mode/2D-echocardiogram and a complete cardiovascular evaluation.  If there are no symptoms present and the evaluation shows only mild to moderate valve stenosis (narrowing) or regurgitation, the aviation medical examiner may issue a certificate; however, a finding of severe valve stenosis with regurgitation will be deferred by the medical examiner and further follow-up will be needed.

Premature Ventricular Contractions (PVCs)

A single PVC on the resting ECG requires no further evaluation.  However, if two or more PVCs appear on the resting electrocardiogram, the FAA will require a cardiovascular evaluation and a graded exercise treadmill test.

Radio Frequency Ablation

Many types of arrhythmias can be successfully treated with catheterization procedures. Radio frequency ablation uses high-frequency energy delivered through an electrode catheter to the area of origin of the abnormal rhythm. The energy that's delivered to the site interrupts the source of the arrhythmia.

For recertification after having RF ablation the FAA requires:

  • 90 days of stabilized recovery. 
  • After the recovery period, a current 24-hour Holter monitor 
  • Resting electrocardiogram (ECG);
  • Medical records and a detailed status report from the treating physician.   

Cardioversion

Spontaneous, Chemical, or Electrical cardioversion:

30-day observation and recovery period; following recovery, you will need to provide the FAA with: 

  • A report of 24-hour Holter with  tracings 
  • A resting ECG report and tracings;
  • Treatment records and a detailed, current status report from the treating physician.. 

Conduction Defects
Although not considered arrhythmias, per se, certain types of electrical conduction defects called bundle branch blocks are not uncommon. These are partial or complete interruptions of the heart's electrical conduction network, or bundle branches, and occur either as left or right blocks. A Right Bundle Branch Block (RBBB) can appear in otherwise normal persons as a completely benign finding, but may be indicative of an adverse cardiac condition. A RBBB in a young person under age 30 normally requires no cardiac evaluation.  Persons over age 30 will need a cardiovascular evaluation and an exercise treadmill stress test or stress echocardiogram.  If the treadmill ECG is normal, no further testing should not be required. The AME may issue the certificate if the study is normal.

A left bundle branch block (LBBB) is more of a concern because of the stronger correlation to coronary artery disease. LBBB makes interpretation of an electrocardiogram difficult because the bundle block masks part of the ECG tracing that identifies possible vessel blockage. A history of   left bundle branch block requires a cardiovascular evaluation and an exercise treadmill stress test with nuclear perfusion imaging.  
 
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