pacemaker

[dpk1nba]

Will a passenger with a pacemaker be affected at all by low altitude (below 12,000 MSL) non-pressurized flying?

 

[wpierce]

Will a passenger with a pacemaker be affected at all by low altitude (below 12,000 MSL) non-pressurized flying?

Only if you use the microwave in the galley!

More seriously, I wouldn't think so as there are plenty of folks in Denver with pacemakers living without a problem. I am not a doctor, though so this could all be proven incorrect.

 

[gprellwitz]

A definite Maybe:
http://www.dartmouth.edu/~cardio/provider/topics/misc/altitude.html

Arrhythmias/ECG Alterations/Pacemakers --Electrocardiographic abnormalities are common at altitude and include increases in p-wave amplitude and rightward axis shift in the frontal leads, presumably a consequence of altitude-induced pulmonary hypertension and right heart overloading [5]. Additional alterations include shortening of the R-R interval, lengthening of the Q-T interval, and ST-T wave flattening. At least some of these ECG changes can be blunted with beta-blocker administration [15], suggesting a role of catecholamines in their development. Since virtually all ECG abnormalities abate upon descent, they are not thought to be clinically important.
The incidence of arrhythmias at altitude is variable and likely depends upon the patient group under study. The relative freedom from arrhythmias among young healthy individuals was documented in a hypobaric chamber study of 8 healthy men aged 21-31 who were observed during exercise at simulated altitudes up to the equivalent of the summit of Mt. Everest and in whom no arrhythmias, conduction defects, or ST-or T-wave changes to suggest ischemia were seen [16].
It is likely that the relative immunity from altitude-induced arrhythmias is not present in less youthful patients. In a Holter monitor study of healthy middle-aged men, the incidence of both supraventricular and ventricular premature beats was nearly doubled at moderate altitude as compared with near sea level baseline [17].
Increased frequency of arrhythmias in an elderly patient is described in a case report by Alexander who documented his rhythm status while ascending Mt. Kilimanjaro during an ascent at age 75 [18]. The incidence of ventricular ectopy rose with increasing altitude, with a rate of 4 per hour at lower altitudes and 56 per hour while climbing above 15,400 feet. Interestingly, the degree of ectopy at a given altitude was more during ascent than with descent, suggesting the synergistic effect of exercise and hypoxia. In comparing his results to a similar climb at age 65, the incidence of ventricular ectopy and presence of ventricular tachycardia was greater with increasing age.
In a previously described study, 10 elderly patients with exercise-induced ischemic changes at sea level and studied acutely at 2500 meters and after five days of acclimatization at 2500 meters, no changes were seen in signal averaged ECG parameters either acutely or following acclimatization [9]. Of note, premature ventricular contractions were significantly increased with acute exposure, but returned to sea level values after acclimatization.
Conflicting data is present on the issue of pacemaker safety at altitude and the possibility of alterations in stimulation thresholds. In an early study simulating altitude with inhalation of 10 percent oxygen, a significant but reversible increases in stimulation thresholds with hypoxia was noted [19]. Interestingly, in another phase of threshold testing in the same report, hypocapnea, induced by mechanic hyperventilation, led to a reduction in pacing stimulation thresholds. In a more contemporary study, however, step-wise simulated hypobaric chamber ascent from 450 meters to 4000 meters showed no change in stimulation threshold in spite of significant fall in PaO2 [20]. It seems likely that the competing effects of hypoxia and hypocapnea, each pushing the pacing stimulation threshold in a different direction, may balance each other and prevent any net change during the physiologic stress of true altitude exposure.
It appears, therefore, that altitude may aggravate arrhythmias in patients with the proper substrate (especially the elderly), particularly during acute exposure, and caution is clearly needed in those with poorly controlled rhythm disorders. Deaths at high altitude are often sudden and while ascertainment of the cause of death is often difficult, the possibility that rhythm-related causes is being underestimated needs to be kept in mind.
Recommendations: Acute exposure to altitude, particularly with exercise, may lead to increased risk of arrhythmias, particularly among those with known arrhythmias, coronary artery disease, and in the elderly. Air travel alone is probably of low risk, except in those with baseline (resting) ventricular and supraventricular arrhythmias in which the added stress of mild hypoxemia might lead to decompensation. Such patients should be cautioned about air travel or be considered for supplemental oxygen. Similar recommendations apply to those contemplating vacationing at high altitude. As with the patient with coronary artery disease or congestive heart failure, the patient should be warned to keep activities less than their sea level baseline, particularly during the first few days at altitude, and should be aware of and treat immediately both cardiac and non-cardiac manifestations of altitude exposure.

{emphasis mine]

 

[wpierce]

Only if you use the microwave in the galley!

More seriously, I wouldn't think so as there are plenty of folks in Denver with pacemakers living without a problem. I am not a doctor, though so this could all be proven incorrect.

Well that didn't take long and Grant's not a doctor either (I don't think...) It wouldn't be a bad idea to have some O2 with you, if you have some.

 

[gprellwitz]

Well that didn't take long and Grant's not a doctor either (I don't think...) It wouldn't be a bad idea to have some O2 with you, if you have some.

Nope, I sure ain't! (But the site I cited appears to be a legit one, not a fly-by-night one where anyone can post.)

 

[Doggtyred]

Will a passenger with a pacemaker be affected at all by low altitude (below 12,000 MSL) non-pressurized flying?

The pacemaker is unaffected by altitude. Its a sealed can with no baroreception ability.

Some pacemakers DO have a rate response mechanism that senses either 1) increased resp rate or 2) physical movement and interpret that as exertion, and increase the heart rate to a programmed higher rate (with a max limit programmed for safety).

So if you have rate responsiveness programmed, and you are breathing fast at altitude to counter hypoxia, you could have a higher than resting paced heart rate. If you become severely hypoxic and acidotic, the pacemaker would likely no longer "capture" the heart properly, but when I say severe, I mean unconscious and/or trying to die. The problem lies with the severely impaired heart tissue, not the pacing device itself, and an unpaced heart in an otherwise healthy person would similarly be impaired.

Grant's quoted article is good reading but inconclusive. Grant's emphasis of precautions are for conditions independent of the pacemaker and its implantation.

 

[gprellwitz]

Grant's quoted article is good reading but inconclusive. Grant's emphasis of precautions are for conditions independent of the pacemaker and its implantation.

And I'll point out that I'm not a doctor, don't play one on TV, and didn't stay at a Holiday Inn Express last night!

 

[Doggtyred]

And I'll point out that I'm not a doctor, don't play one on TV, and didn't stay at a Holiday Inn Express last night!

Me neither!

 

[bbchien]

To the OP: Nope. But persons who are pacer reliant generally have other reasons to need O2 well below 12,000. I'd be happier if your quex said "8,000 feet".

 

[dpk1nba]

To the OP: Nope. But persons who are pacer reliant generally have other reasons to need O2 well below 12,000. I'd be happier if your quex said "8,000 feet".

I will be able to keep the flight under 8500 MSL. Only 1 mountain pass to get over. I intend to leave early AM so as to keep it a relatively smooth ride at the lower altitude. Thanx for the help Dr. Bruce.

 

[poadeleted20]

I will be able to keep the flight under 8500 MSL. Only 1 mountain pass to get over. I intend to leave early AM so as to keep it a relatively smooth ride at the lower altitude. Thanx for the help Dr. Bruce.

I think Bruce is trying to tell you that the pacemaker passenger should have supplemental O2 passing 8500, which is long before FAR 91.211 requires it.

 

[bbchien]

Well, he probably oughtta have an oximetry check crossing 8,000. 12,000 he NEEDS an oximetry check crossing 10,000, and oxygen if any of these are below 90%.

 

[dpk1nba]

Well, he probably oughtta have an oximetry check crossing 8,000. 12,000 he NEEDS an oximetry check crossing 10,000, and oxygen if any of these are below 90%.

I have O2 available on the plane so I'm not too worried. The passenger's Doc said it shouldn't be an issue especially if O2 is onboard.