Hypobaric hypoxia i.e. hypoxia due to the lowered oxygen pressure at altitude, is a potential concern for travellers with cardiovascular disease. In some patients arterial oxygen saturation may fall sufficiently to trigger the physiological responses to hypoxia, with an increase in ventilation and a mild tachycardia, resulting in increased myocardial oxygen demand. In patients with limited cardiac reserve, the use of supplemental oxygen (Table 1) may be required and most commercial airlines will supply this when requested in advance, although a charge may be levied. Some airlines may permit passengers to carry and use their own oxygen cylinders and passengers who wish to do this should contact the airline for information on their policy. Passengers may also be able to use approved portable oxygen concentrators and again, those wishing to do so, should discuss this with the airline.
|Cardiovascular indications for medical oxygen during commercial airline flights|
Use of oxygen at baseline altitude
CHF NYHA class III - IV or baseline PaO2 less than 70 mm Hg
Angina CCS class III-IV
Cyanotic congenital heart disease
Primary pulmonary hypertension
Other cardiovascular diseases associated with known baseline hypoxemia
CHF - Congestive Heart Failure
Despite the physiological changes that occur at altitude, the majority of patients with cardiac conditions can travel safely as long as they are cautioned to carry their medications in their hand baggage.
Angina Pectoris, if stable, is usually not a problem in flight.
Patients with a recent myocardial infarction may travel after 7 to 10 days if there are no complications. If the patient has undergone an exercise test which shows no residual ischemia or symptoms, this may be helpful, but is not a mandatory requirement.
Coronary Artery Bypass Grafting (CABG) and other chest or thoracic surgery should prove no intrinsic risk in the aviation environment as long as the patient has fully recovered without complications. However, as air is transiently introduced into the thoracic cavity, there is a potential risk for barotrauma due to the gaseous expansion which occurs at altitude. It is therefore prudent that patients should wait until the air is reabsorbed, approximately 10 to 14 days before travelling by air.
Patients with uncomplicated Percutaneous Coronary Interventions such as angioplasty with stent placement may be fit to travel after 3 days, but individual assessment is essential.
Symptomatic valvular heart disease is a relative contraindication to airline travel. Individual assessment by the treating physician is essential, paying particular attention to the functional status, severity of symptoms and left ventricular function, in addition to the presence or absence of pulmonary hypertension.
There is no contraindication to air travel for patients with treated hypertension, as long as it is under satisfactory control and the patient is reminded to carry their medication with them on the flight.
Those with pacemakers and implantable cardioverter defibrillators may travel without problems by air once they are medically stable. Interaction with airline electronics or aviation security devices is highly unlikely for the most common bi-polar configuration.
Following a cerebrovascular accident, patients are advised to wait 10 days following an event, although if stable may be carried within 3 days of the event. For those with cerebral arterial insufficiency, supplementary oxygen may be advisable to prevent hypoxia.
Clinical judgement has an important role in the individual assessment of fitness to fly. However, some cardiovascular contraindications to flight are shown in Table 2.
|Cardiovascular contraindications to commercial airline flight|
Uncomplicated myocardial infarction within 7 days
Complicated myocardial infarction within 4-6 weeks
Decompensated congestive heart failure
CABG within 10 days
CVA within 3 days
Uncontrolled cardiac arrhythmia
Severe symptomatic valvular heart disease