Altitude and TravelAltitude and Travel

Philippe LagacPhilippe Lagacéé--WiensWiensMD, DTM&H, FRCPCMD, DTM&H, FRCPC

OutlineOutline

Basic physiology of altitude medicineBasic physiology of altitude medicineThe dangers of altitude and acute altitude The dangers of altitude and acute altitude illnesses.illnesses.Diagnosis of altitude related illnessesDiagnosis of altitude related illnessesTreatment of altitude related illnessesTreatment of altitude related illnessesPrevention of altitude illnesses.Prevention of altitude illnesses.Altitude illness in special populations.Altitude illness in special populations.

Altitude medicine Altitude medicine –– the basicsthe basics

Oxygen makes up roughly 21% of the gases Oxygen makes up roughly 21% of the gases in our atmosphere.in our atmosphere.Normal atmospheric pressure is 760 mm Normal atmospheric pressure is 760 mm Hg, Hg, –– Normal oxygen pressure is 159 mmHg.Normal oxygen pressure is 159 mmHg.As elevation increases, atmospheric As elevation increases, atmospheric pressure decreases (pressure decreases (oxygen concentration oxygen concentration stays the samestays the same).).

What does it mean?What does it mean?

In Winnipeg, oxygen pressure is 155 mmHg In Winnipeg, oxygen pressure is 155 mmHg ((““97%97%””))In Cusco, Peru oxygen pressure is : 100 mmHg In Cusco, Peru oxygen pressure is : 100 mmHg ((““65%65%””))In Lhasa, Tibet: 96 mmHg (In Lhasa, Tibet: 96 mmHg (““60%60%””))In La Paz, Bolivia: 92 mmHg (In La Paz, Bolivia: 92 mmHg (““58%58%””))Mt. Kilimanjaro: 73 mmHg (Mt. Kilimanjaro: 73 mmHg (““48%48%””))

Oxygen physiologyOxygen physiology

Haemoglobin carries oxygen from the lungs to the Haemoglobin carries oxygen from the lungs to the tissues.tissues.The amount of oxygen carried depends on the The amount of oxygen carried depends on the amount of oxygen in the lung and amount of amount of oxygen in the lung and amount of haemoglobin.haemoglobin.Haemoglobin is can be fully saturated as long as Haemoglobin is can be fully saturated as long as the atmospheric Othe atmospheric O2 2 pressure is over 115.pressure is over 115.–– Occurs at about 2500mOccurs at about 2500m

Adaptations to low oxygen pressureAdaptations to low oxygen pressure

Short term:Short term:–– HyperventilationHyperventilation

Increases oxygen in lungs by reducing COIncreases oxygen in lungs by reducing CO22

Also increases pHAlso increases pH

–– Renal acidRenal acid--base changes, disordered ventilationbase changes, disordered ventilationCompensates for pH increaseCompensates for pH increase

–– Local tissue responses to low oxygenLocal tissue responses to low oxygen

Long term:Long term:–– Not an issue in acute mountain sicknessNot an issue in acute mountain sickness–– Involves slow increase in oxygen carrying capacity.Involves slow increase in oxygen carrying capacity.

Dangers of altitude Dangers of altitude –– Many Many forms!forms!

Lower oxygen tensionLower oxygen tension–– Drops by 80 mm (~10 kPa) for each 1000 mDrops by 80 mm (~10 kPa) for each 1000 mIncreased UV radiationIncreased UV radiation–– Up 14% for each 1000mUp 14% for each 1000mLower temperaturesLower temperatures–– --6.56.5ººC for each 1000mC for each 1000m

Illnesses associated with altitudeIllnesses associated with altitudeOxygenOxygen--relatedrelated–– Acute hypoxiaAcute hypoxia–– AMSAMS–– HAPEHAPE–– HACEHACE–– Peripheral OedemaPeripheral Oedema–– PE/Thromboembolism/strokePE/Thromboembolism/stroke–– RetinopathyRetinopathy–– Disordered/periodic breathingDisordered/periodic breathing

Physical environment relatedPhysical environment related–– ExposureExposure–– SunburnSunburn–– Snow blindnessSnow blindness

HAFE HAFE –– Still ignored...Still ignored...

Altitude associated illness Altitude associated illness –– Diagnosis and TreatmentDiagnosis and Treatment

Acute hypoxiaAcute hypoxiaAMS and HACEAMS and HACEHAPEHAPEDisordered breathingDisordered breathing

Acute hypoxiaAcute hypoxia

Rapid reaction to sudden drop in oxygen tension.Rapid reaction to sudden drop in oxygen tension.Occurs minutes to hours after exposureOccurs minutes to hours after exposureCan be triggered by exertion or other factors that Can be triggered by exertion or other factors that drop blood oxygen level while at altitude.drop blood oxygen level while at altitude.Dizziness, hallucinations, tinnitus, loss of Dizziness, hallucinations, tinnitus, loss of consciousness can occur.consciousness can occur.Almost guaranteed to occur in unacclimatized Almost guaranteed to occur in unacclimatized persons over ~5500mpersons over ~5500m

Acute hypoxia Acute hypoxia -- TreatmentTreatment

Descent and oxygen.Descent and oxygen.Correct causes or triggers of hypoxia.Correct causes or triggers of hypoxia.Encouraging hyperventilation can temporize.Encouraging hyperventilation can temporize.

Acute Mountain SicknessAcute Mountain Sickness

The bodyThe body’’s response to a sudden change in s response to a sudden change in oxygen pressure and subsequent modest oxygen pressure and subsequent modest hypoxaemia.hypoxaemia.Clinically differs from acute hypoxia.Clinically differs from acute hypoxia.–– Occurs 6 Occurs 6 –– 12 hours after elevation. 12 hours after elevation.

Results in a clinical syndrome characterized by:Results in a clinical syndrome characterized by:–– Headache which can progress to debilitating.Headache which can progress to debilitating.–– Fatigue which can progress to lassitude.Fatigue which can progress to lassitude.–– Insomnia, paroxysmal nocturnal breathing.Insomnia, paroxysmal nocturnal breathing.–– Poor appetite which can progress to vomitingPoor appetite which can progress to vomiting..

AMS AMS -- diagnosisdiagnosis

Lake Louise score commonly used to Lake Louise score commonly used to diagnose AMS.diagnose AMS.

Altitude headacheAltitude headache

Cardinal symptom of AMS.Cardinal symptom of AMS.–– Throbbing, frontal/bitemporalThrobbing, frontal/bitemporal–– Worse in morning and at night.Worse in morning and at night.–– PosturalPosturalSimilar to a Similar to a ““hangoverhangover”” headache in quality.headache in quality.

Disordered breathing and sleep Disordered breathing and sleep apneaapnea

Common finding at altitudes >3000mCommon finding at altitudes >3000mUsually in the form of periodic breathing and Usually in the form of periodic breathing and apnea during sleep.apnea during sleep.Leads to poor sleep, somnolence, Leads to poor sleep, somnolence, headache.headache.Caused by competing respiratory drives.Caused by competing respiratory drives.

High Altitude Cerebral EdemaHigh Altitude Cerebral Edema

HACE is endHACE is end--stage AMS:stage AMS:–– Hypoxia causes fluid leak into brain tissue, causing Hypoxia causes fluid leak into brain tissue, causing

brain swelling and inflammation.brain swelling and inflammation.

Symptoms are similar to AMS but more severe. Symptoms are similar to AMS but more severe. AMS with any of the following should be AMS with any of the following should be considered HACE.considered HACE.–– AtaxiaAtaxia–– ConfusionConfusion–– Altered consciousness/behaviourAltered consciousness/behaviour–– ComaComa–– Severe vomitingSevere vomiting

Treatment of AMSTreatment of AMS

The only 100% effective treatment for AMS The only 100% effective treatment for AMS is increasing oxygen pressure.is increasing oxygen pressure.–– This means This means descentdescent, , oxygen or a pressure chamber.oxygen or a pressure chamber.

Anybody with symptoms of HACE or severe Anybody with symptoms of HACE or severe AMS must descend!AMS must descend!–– Other modalities only adjunctiveOther modalities only adjunctive

Mild AMSMild AMS

Headache, nausea, fatigue, dizziness, insomnia Headache, nausea, fatigue, dizziness, insomnia can be treated symptomatically.can be treated symptomatically.–– NSAIDs and acetaminophen have been shown to be NSAIDs and acetaminophen have been shown to be

equivalent for headache.equivalent for headache.–– AntiAnti--emetics (prochlorperazine and promethazine)emetics (prochlorperazine and promethazine)–– Acetazolamide can be used to treat (250mg in two Acetazolamide can be used to treat (250mg in two

doses 8 hours apart)doses 8 hours apart)–– Sedatives or benzodiazepines may contribute to Sedatives or benzodiazepines may contribute to

disordered breathing.disordered breathing.

Severe AMSSevere AMS

Severe headache, vomiting, anorexia, Severe headache, vomiting, anorexia, peripheral oedema without HACE or HAPE.peripheral oedema without HACE or HAPE.–– Descent to lower altitude with acclimatization. Descent to lower altitude with acclimatization.

As little as 500 meters can be very helpful.As little as 500 meters can be very helpful.–– Acetazolamide 250mg then 250mg 8 hours Acetazolamide 250mg then 250mg 8 hours

later. later. –– Dexamethasone 4 mg every 6 hours.Dexamethasone 4 mg every 6 hours.

Combine with descent or acetazolamide!Combine with descent or acetazolamide!

–– Oxygen or pressure chamber to facilitate Oxygen or pressure chamber to facilitate descent.descent.

HACEHACE

Descent to lower altitude.Descent to lower altitude.Oxygen or pressure chamber to facilitate Oxygen or pressure chamber to facilitate descent.descent.Dexamethasone 4 mg every six hours after Dexamethasone 4 mg every six hours after 8mg loading dose.8mg loading dose.Furosemide and other diuretics can be Furosemide and other diuretics can be considered but quality evidence is lacking.considered but quality evidence is lacking.

High Altitude Pulmonary EdemaHigh Altitude Pulmonary Edema

Hypoxia and reduced pulmonary gas exchange Hypoxia and reduced pulmonary gas exchange increases pulmonary artery pressure and results in increases pulmonary artery pressure and results in capillaries leak into lungs.capillaries leak into lungs.–– Usually 2 Usually 2 –– 4 days after ascent.4 days after ascent.–– AMS not always coAMS not always co--existing.existing.–– Manifests as persistent dry cough, severe dyspnea and Manifests as persistent dry cough, severe dyspnea and

disproportionately limited exercise tolerance.disproportionately limited exercise tolerance.–– Fever (<38.5Fever (<38.5ººC), tachypnea and diffuse crackles are C), tachypnea and diffuse crackles are

common.common.–– Haemoptysis/pink sputum is late finding.Haemoptysis/pink sputum is late finding.

HAPE HAPE -- diagnosisdiagnosis

Two of: chest tightness, cough, dyspnea at Two of: chest tightness, cough, dyspnea at rest, and markedly decreased exercise rest, and markedly decreased exercise performance and...performance and...Two of: central cyanosis, pulmonary Two of: central cyanosis, pulmonary crackles, crackles, tachycardia >110 and tachypnea tachycardia >110 and tachypnea >20>20Caution with scoring systems!Caution with scoring systems!

HAPE HAPE -- TreatmentTreatment

Descent to lower altitude.Descent to lower altitude.Oxygen or pressure chamber to facilitate Oxygen or pressure chamber to facilitate descent.descent.Drugs play a small role in management.Drugs play a small role in management.–– Nifedipine XR 30mg BID, Nitric oxideNifedipine XR 30mg BID, Nitric oxide–– Furosemide with or without morphine (standard Furosemide with or without morphine (standard

of care for pulmonary oedema) remains of care for pulmonary oedema) remains controversial.controversial.

–– Role of dexamethasone is not clear.Role of dexamethasone is not clear.

Prediction and PreventionPrediction and Prevention

Who gets AMS?Who gets AMS?There is no way to predict who will get AMS.There is no way to predict who will get AMS.AMS does not typically occur below 2000m ASL.AMS does not typically occur below 2000m ASL.Faster ascents and group excursions more risky.Faster ascents and group excursions more risky.Younger people at highest risk.Younger people at highest risk.–– More vigorous ascents.More vigorous ascents.–– Less Less ““freefree”” intracranial space.intracranial space.

Personal history of AMS, HACE or HAPE.Personal history of AMS, HACE or HAPE.Residence below 900m.Residence below 900m.No apparent association with gender, physical No apparent association with gender, physical fitness, load.fitness, load.

AMS RiskAMS Risk

HighHigh

Very highVery high

ExtremeExtreme

Pleasantly invigorating

Rather challenging

Frankly insane

Genetic basis of AMSGenetic basis of AMS

Genetically determined anatomical variations.Genetically determined anatomical variations.Activity of key enzymesActivity of key enzymes–– NO synthase in HAPENO synthase in HAPE–– ACE polymorphismsACE polymorphisms

Gender differences?Gender differences?–– Overall men more likely to get AMS Overall men more likely to get AMS –– behavioural.behavioural.–– No clear gender differences when other factors are No clear gender differences when other factors are

adjusted.adjusted.

Hereditary aspect of AMS.Hereditary aspect of AMS.

Prevention of AMS, HACE and Prevention of AMS, HACE and HAPEHAPE

BehaviourBehaviour–– Altering behaviour to reduce likelihood of AMS.Altering behaviour to reduce likelihood of AMS.PharmacologicalPharmacologicalPhysicalPhysical–– Methods to increase oxygen pressure.Methods to increase oxygen pressure.

BehaviouralBehavioural

Slow ascent with acclimatization points, especially Slow ascent with acclimatization points, especially at high altitude (>3000m).at high altitude (>3000m).–– 400m/ day is reasonable.400m/ day is reasonable.–– One acclimatization day for each 3 days of increase.One acclimatization day for each 3 days of increase.

NeverNever overnight at higher altitude than where overnight at higher altitude than where symptoms start. symptoms start. –– Climb high, sleep low.Climb high, sleep low.

Avoid sedatives or alcohol.Avoid sedatives or alcohol.Know the symptoms and ensure groups Know the symptoms and ensure groups understand individual variability. understand individual variability. Mild activity (no overexertion).Mild activity (no overexertion).

Diet?Diet?

High carbohydrate diet (carboHigh carbohydrate diet (carbo--loading) with >70% loading) with >70% of calories from carbohydrates reduces the risk of of calories from carbohydrates reduces the risk of AMS.AMS.Role of hydration and hyperhydration is in Role of hydration and hyperhydration is in question.question.–– Association exists between AMS and dehydration, but Association exists between AMS and dehydration, but

not apparently causal.not apparently causal.–– Dehydration can contribute to symptoms.Dehydration can contribute to symptoms.–– Adequate hydration probably helps acidAdequate hydration probably helps acid--base base

normalization.normalization.–– May prevent thromboembolic phenomena.May prevent thromboembolic phenomena.

Chemoprophylaxis of AMSChemoprophylaxis of AMS

AMSAMS–– Acetazolamide, dexamethasoneAcetazolamide, dexamethasoneHACEHACE–– Acetazolamide, dexamethasoneAcetazolamide, dexamethasoneHAPEHAPE–– Sildenafil, Tadadifil, Nifedipine, SalmeterolSildenafil, Tadadifil, Nifedipine, Salmeterol

AcetazolamideAcetazolamide

Carbonic anhydrase inhibitor.Carbonic anhydrase inhibitor.–– Increases renal output of bicarbonate causing metabolic Increases renal output of bicarbonate causing metabolic

acidosis.acidosis.–– Accelerates normal physiological changes in response Accelerates normal physiological changes in response

to altitude.to altitude.–– Stimulates ventilation (peripheral CA)Stimulates ventilation (peripheral CA)

125125--250mg po BID starting 24 hours pre250mg po BID starting 24 hours pre--ascent ascent and ending 48 hours after maximum altitude is and ending 48 hours after maximum altitude is effective for AMS prevention.effective for AMS prevention.Reduces severity of symptoms. Reduces severity of symptoms. –– Paroxysmal nocturnal breathing, insomnia, headacheParoxysmal nocturnal breathing, insomnia, headache..

AcetazolamideAcetazolamide

Indications:Indications:–– Rapid ascent to >3000m or rapid increase in sleep altitude (e.g.Rapid ascent to >3000m or rapid increase in sleep altitude (e.g.

4000 to 5000m in one day).4000 to 5000m in one day).–– Past history of AMS or HACE.Past history of AMS or HACE.

Side effects can be disturbing...Side effects can be disturbing...–– Annoying to painful paresthesias of fingers/toes.Annoying to painful paresthesias of fingers/toes.–– Taste alteration of carbonated beverages.Taste alteration of carbonated beverages.–– Diuresis, cloudy urine, nausea.Diuresis, cloudy urine, nausea.–– RARE: Myelosuppression, SJS, crytaluria.RARE: Myelosuppression, SJS, crytaluria.

Start with lowest effective dose (125 mg BID)Start with lowest effective dose (125 mg BID)People with sulfa allergy CAN take.People with sulfa allergy CAN take.

DexamethasoneDexamethasone

Considered second line due to side effects.Considered second line due to side effects.May prevent HACE and HAPE by reducing May prevent HACE and HAPE by reducing capillary leak and inflammation.capillary leak and inflammation.Reduces incidence of headache, vomiting.Reduces incidence of headache, vomiting.Is more effective when combined with Is more effective when combined with acetazolamide.acetazolamide.Dose for prevention is 4mg BID.Dose for prevention is 4mg BID.

NifedipineNifedipine

Should not be used to prevent HAPE.Should not be used to prevent HAPE.–– Only shown to be effective in preventing HAPE Only shown to be effective in preventing HAPE

in individuals with repeated history of HAPE in individuals with repeated history of HAPE going to high altitude.going to high altitude.

Recommended only in limited situations.Recommended only in limited situations.–– Individuals with recurrent HAPE and needing to Individuals with recurrent HAPE and needing to

go at high altitude without access to oxygen or go at high altitude without access to oxygen or ability for slow ascent.ability for slow ascent.

cGMP phosphodiesterase type 5 cGMP phosphodiesterase type 5 inhibitorsinhibitors

Sildenafil (ViagraSildenafil (Viagra™™) and Tadalafil (Cialis) and Tadalafil (Cialis™™) ) have been shown to be effective in have been shown to be effective in preventing HAPE and improving gas preventing HAPE and improving gas exchange and should be considered in exchange and should be considered in people with a history of HAPE who must people with a history of HAPE who must ascend rapidly.ascend rapidly.

ββ--adrenergic agonistsadrenergic agonists

Salmeterol, taken prophylactically at 125Salmeterol, taken prophylactically at 125μμg g every 12 hours reduced incidence of HAPE every 12 hours reduced incidence of HAPE by 50% in subjects with a previous episode by 50% in subjects with a previous episode of HAPE.of HAPE.

Other drugs for preventionOther drugs for prevention

Temazepam has been shown to reduce Temazepam has been shown to reduce periodic breathing.periodic breathing.Theophylline (caffeineTheophylline (caffeine--like analog) @ 250 like analog) @ 250 mg BID effective to reduce AMS.mg BID effective to reduce AMS.Sumatriptan reduced symptoms of AMS Sumatriptan reduced symptoms of AMS when taken prophylactically in one study.when taken prophylactically in one study.

Summary of pharmacological Summary of pharmacological management of AMS syndromesmanagement of AMS syndromes

PREVENTION TREATMENTDrug AMS HACE HAPE AMS HACE HAPEAnalgesics (e.g. Ibuprophen) Yes Yes No Yes Yes NoAcetazolamide Yes Yes ? Yes No NoDexamethasone Yes Yes ? Yes Yes NoNifedipine No No ? No No YesFurosemide No No No No No ?Salbutamol No No Yes No No NoSildenafil/Tadalafil No No Yes No No NoTheophylline Yes ? No No No NoNitric oxide No No No No No Yes

Descent, oxygen and barotherapy are effective for all forms on altitude illness and should be considered first line for all severe forms of the disease.

Physical (oxygen)Physical (oxygen)

Use of oxygen as prevention for AMS is not Use of oxygen as prevention for AMS is not routine.routine.Used to prevent severe AMS at extreme Used to prevent severe AMS at extreme altitudesaltitudesUsed intermittently, nocturnally or Used intermittently, nocturnally or continuously.continuously.Used prophylactically on train to LhasaUsed prophylactically on train to Lhasa

Special populationsSpecial populations

Certain populations require special Certain populations require special considerations at high altitude:considerations at high altitude:–– ChildrenChildren–– Pregnant womenPregnant women–– DiabeticsDiabetics–– Underlying diseases of cardiovascular and Underlying diseases of cardiovascular and

respiratory system.respiratory system.

ChildrenChildren

May be more susceptible to AMS.May be more susceptible to AMS.–– Quality studies are lackingQuality studies are lackingDifficult to assess symptoms of AMS in Difficult to assess symptoms of AMS in young children.young children.Symptoms same in children over 8 years.Symptoms same in children over 8 years.–– Use Lake Louise ScoreUse Lake Louise ScoreModified Lake Louise score recommended Modified Lake Louise score recommended in children less than 8 years old.in children less than 8 years old.

Modified Lake Louise ScoreModified Lake Louise Score

Unexplained fussiness intensity and Unexplained fussiness intensity and amount.amount.How well child is eating.How well child is eating.How playful child is.How playful child is.How well child is sleeping.How well child is sleeping.

PregnancyPregnancy

Theoretical risks:Theoretical risks:–– Altitude = remotenessAltitude = remoteness

Access to care in case of complications, early Access to care in case of complications, early labour...labour...

–– Reduced oxygen delivery to foetusReduced oxygen delivery to foetus–– Dehydration and thrombosisDehydration and thrombosis

PregnancyPregnancy

Simulated altitude up to 2600 m doesnSimulated altitude up to 2600 m doesn’’t appear to t appear to harm the foetus.harm the foetus.–– Oxygen levels remain normal.Oxygen levels remain normal.–– Caution reasonable if there are complications.Caution reasonable if there are complications.

Women living at altitude have a higher than Women living at altitude have a higher than expected rate of miscarriage and LBW.expected rate of miscarriage and LBW.–– Reasons unclear, not significant in acute exposure.Reasons unclear, not significant in acute exposure.

Dehydration can exacerbate hypercoagulable Dehydration can exacerbate hypercoagulable state.state.Hypercoagulability after longHypercoagulability after long--term exposure.term exposure.

DiabetesDiabetes

Risk of AMS, HACE and HAPE appear no different.Risk of AMS, HACE and HAPE appear no different.Glycemic control is profoundly affected by exercise and Glycemic control is profoundly affected by exercise and altitude.altitude.–– Need very careful monitoring and expect poor control.Need very careful monitoring and expect poor control.–– Ketoacidosis can occurKetoacidosis can occur

Anorexia is common with altitude.Anorexia is common with altitude.

Temperature and environmental Temperature and environmental considerations.considerations.–– Medications, shivering etc...Medications, shivering etc...

Diabetes and AMS prophylaxisDiabetes and AMS prophylaxis

Acetazolamide can predispose individuals to Acetazolamide can predispose individuals to ketoacidosis.ketoacidosis.Dexamethosone causes hyperglycemia and Dexamethosone causes hyperglycemia and can lead to ketoacidosis.can lead to ketoacidosis.

COPDCOPD

Individuals with COPD and asthma cannot Individuals with COPD and asthma cannot compensate as well for hypoxia with compensate as well for hypoxia with hyperventilation.hyperventilation.With COPD, FEVWith COPD, FEV1 1 > 1.5L and expected > 1.5L and expected PaOPaO22 > 55mmHg> 55mmHg–– PaOPaO2Alt2Alt = (0.52PaO= (0.52PaO22 ) + (11.9FEV) + (11.9FEV11 ) ) –– 1.761.76

AsthmaAsthma

Patients with mild intermittent or mild persistent Patients with mild intermittent or mild persistent disease (controlled) may ascend to altitudes as disease (controlled) may ascend to altitudes as high as 5000 m.high as 5000 m.Caution patients with more severe disease against Caution patients with more severe disease against highhigh--altitude travel, particularly into remote areas.altitude travel, particularly into remote areas.–– Should have excellent controlShould have excellent control

Continue baseline medications and carry peak Continue baseline medications and carry peak flow meter and supply of rescue inhalers and flow meter and supply of rescue inhalers and prednisone for potential exacerbationsprednisone for potential exacerbationsConsider using balaclava or bandana over mouth Consider using balaclava or bandana over mouth to warm and humidify air in cold environments.to warm and humidify air in cold environments.

Pulmonary hypertensionPulmonary hypertension

Should be counselled against going to high Should be counselled against going to high altitude. altitude. No trials to assess risk, but theoretical risk No trials to assess risk, but theoretical risk of HAPE.of HAPE.If travel not avoidable, use HAPE If travel not avoidable, use HAPE prophylaxis, oxygen.prophylaxis, oxygen.

Angina, CAD and Heart FailureAngina, CAD and Heart Failure

No increased risk of AMS, HACE or HAPE.No increased risk of AMS, HACE or HAPE.Higher risk of effort angina and dysrythmia.Higher risk of effort angina and dysrythmia.Minimal exertion at moderate altitude in well Minimal exertion at moderate altitude in well compensated patients is low risk.compensated patients is low risk.RecommendationsRecommendations–– Gradual ascent. Gradual ascent. –– Ensure BP, heart rate/rhythm control. Ensure BP, heart rate/rhythm control. –– Limitation of activity to less than the symptomLimitation of activity to less than the symptom--limiting limiting

degree at sea level, especially during the first 1 to 3 degree at sea level, especially during the first 1 to 3 days.days.

Angina, CAD and Heart FailureAngina, CAD and Heart Failure

Counsel against high altitude if:Counsel against high altitude if:–– NewNew--onset or unstable angina. onset or unstable angina. –– Frequent or highFrequent or high--grade ventricular ectopy.grade ventricular ectopy.–– Severe or poorly controlled hypertension.Severe or poorly controlled hypertension.–– CoCo--existing pulmonary diseaseexisting pulmonary diseaseMyocardial infarction within several weeks Myocardial infarction within several weeks or months is a relative contraindication.or months is a relative contraindication.

Take home pointsTake home points

Altitude sickness is preventable.Altitude sickness is preventable.–– Behavioural and pharmacological approaches exist.Behavioural and pharmacological approaches exist.

People travelling to areas above 2500 m should People travelling to areas above 2500 m should be aware of altitude sickness.be aware of altitude sickness.People going to very high altitude, who are People going to very high altitude, who are anxious about altitude sickness or who are anxious about altitude sickness or who are pregnant or have underlying pulmonary, cardiac or pregnant or have underlying pulmonary, cardiac or chronic disease should be referred to an expert.chronic disease should be referred to an expert.

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