Bradycardia

Bradycardia, or persistent slow pulse, is much rarer than the

persistent rapid pulse discussed at the beginning of the chapter on

tachycardia. Cases are, indeed, sufficiently rare to be medical

curiosities. Prof. Clifford Allbutt has called attention to the fact

that the status of bradycardia or brachycardia, as Osler (following

Riegel because of the analogue tachycardia) prefers to call it, is

very different from that of tachycardia. In the latter, especially, in

the specific sense of the term, the symptoms occur paroxysmically,

endure for a definite length of time and then there is a return to the

normal pulse rate. For this, or at least for the condition known as

essential tachycardia, there is no well-defined cause and no definite

pathological lesion. Bradycardia or brachycardia, however, is usually

present as the result of some known physiologic or pathologic

condition; it endures as long as the cause continues to act and then

ceases, usually not to return unless the same cause gives rise to it

again.







There are some cases, however, of slow pulse that cannot be traced to

any definite lesion and in which the pulse is much slower at certain

times than at others, though without its being possible to trace any

definite immediate cause. These cases seem to be physiological

analogues of tachycardia. In tachycardia there is an irritation of the

accelerator nerves to the heart, in brachycardia of the inhibitory

nerves.





Depressed Mental States.--Occasionally the reason for this can be

found, though it is rather vague. In depressed mental states, for

instance, a pulse between fifty and sixty is common. In people who

suffer from periodic fits of depression it is not unusual to find that

in the early morning the pulse is not more than fifty-five. I have

seen patients who were worrying about their hearts present records of

early morning pulse before they got up that were always below sixty.

This is probably in a certain number of people quite normal. I

remember a series of observations made on the attendants in the

Charite Hospital in Berlin in which it was clear that the normal

German morning temperature at seven a.m. was below 97 F., while the

pulses were always below sixty. A reassurance of this kind is helpful

to patients who have acquired the bad habit of taking their own pulse

and have been disturbed by finding it so much below what they consider

normal.





Illustrative Case.--A number of cases of persistent slow pulse seem to

be congenital or produced by some definite pathological lesion, yet do

not prove serious for the patient. Some years ago I described one of

these cases in a paper read before the Section on Medicine of the New

York Academy of Medicine [Footnote 29] and I have had the opportunity

to follow it for about fifteen years. Though the patient's pulse is

usually below forty and even after a rapid walk does not rise above

fifty, she is in reasonably good health and during those years has

buried two husbands. When I saw her she was compelled to go up and

down stairs frequently and yet did not experience much difficulty.

While patients suffering from palpitation would find it impossible,

because of the discomfort produced, to make the journeys up and down

stairs that she did, she felt only about as much respiratory

discomfort as would come to a woman of her size. Her respirations were

somewhat hurried--22 to 24 to the minute--but her general health was

very good. Her urine was normal, her liver not enlarged, her ordinary

organic functions were not disturbed and there was no sign of arterial

degeneration.



[Footnote 29: The Medical News, November 10, 1900.]



With the pulse rate as low as this one might expect to find the

patient phlegmatic, slow of movement and not readily moved to emotion.

On the contrary, she has always been rather nervous and high-strung

and inclined to be excitable. Her cardiac condition was first noted

just after the first grip epidemic in this country, though her

attention was not called to it during the course of the grip. It seems

probable that the heart condition was acquired as a consequence of

some irritative lesion affecting the inhibitory nerves to the heart

that developed at that time. After her heart condition had been

discovered she was for a time a skirt dancer and frequently danced for

the amusement of her friends. She was always lively and active and

after her first husband's death, when it became necessary for her to

earn her own living, she was on the stage for a time and danced

without any embarrassment of either heart or respiration. As a

consequence of running down in weight and general health, owing to

conditions since her husband's death, she noticed that dancing proved

exhausting to her and she gave it up.



In general, she considered herself quite as capable as any of her

friends for the ordinary duties and amusements of life. When I first

saw her her digestion had been somewhat disturbed by worries and

unsuitable nutrition taken at irregular intervals and this, I think,

accounted much more than her heart for her complaint of tiredness on

exertion. Later, after her second marriage, when she was in better

circumstances, all her symptoms disappeared and even her heart rate

rose so that it was seldom below forty, and after exertion always went

to fifty. What was needed in her case more than anything was a change

of environment, the satisfaction of mind that comes with freedom from

worries and the cares of making her own living, and the improvement in

digestion due to regular meals of good, simple, nutritious food.





Compatibility with Health and Activity.--The above case is interesting

as illustrating mental influence upon such a serious condition as

bradycardia. Most people who suffer from it are likely to be

over-depressed and this reacts to disturb digestion and also further

to disturb the heart itself. What these patients need above all, then,

is reassurance with regard to their condition. There are some striking

examples in history and in medical literature of bradycardia or

persistent slow pulse in persons who are able to accomplish a large

amount of work and whose general health and capacity for

accomplishment were not at all disturbed by this physical condition.

Above all, they were not depressed and did not lack initiative.

Napoleon I, whose pulse is said normally to have been about forty,

rising during the excitement of battle to fifty, is a typical example.

Medical literature records a number of patients with congenital slow

pulse without any discernible heart lesion who lived long and

successful lives. One of these was a very successful English athlete.

The prognosis of these cases is not as bad as it might seem to be and

the mental state of the patient is more important than anything else

in the treatment.