Comunicaciones en los Comoro

Evaluation of the cardiac rhythm

Catch of pulse

The manner simplest to evaluate the cardiac rhythm is to take the Pouls. That consists in supporting with the fingers, through the skin, a Artère against a Os; the pulp of the fingers makes it possible to feel swellings of the artery due to the increase in the blood Pressure by the contraction of the Cœur (Systole).

To take the pulse, it is necessary to use the fingers other than the inch, because an artery passes at the end of the inch and the “pulse of the inch” can disturb measurement.

The perception or not of a central or distal pulse is also a method of estimate of the tension (see blood Pressure > Estimation without material ).

Strategy of catch of pulse

The pulse is more easily perceptible with the large arteries than are the arteries carotid and femoral (central pulses). The catch of pulse to the wrist (radial pulse) is more comfortable, but it can happen that one feels the central pulses and not the radial pulse, in particular if the blood pressure is low; this situation is frequent at a person having health issues, and in particular in the event of accident or of faintness.

A serious evaluation of the circulatory function of a person who breathes thus includes/understands:

an evaluation of the frequency (beats per minute) and of the regularity of the cardiac rhythm on a pulse central
the pulse carotidien is more accessible, and the proximity of the Sexe returns the catch of the femoral pulse delicate; this evaluation will thus be made in priority on the pulse carotidien, except if its access is difficult (for example fat neck, presence of a cervical Collier);
a checking of the presence and symmetry of the radial pulse: if the radial pulse is absent from the two sides, that can indicate an arterial low pressure; if it is perceived only one side, that can indicate a compression of the artery or a Hémorragie on the side where it is not perceived, in particular in the event of Traumatisme (Fracture, Luxation) of the upper limb, or compression (imprisonment in a vehicle, compression by a heavy object, a collapse…) ;
these elements are to be corroborated with other elements external like the presence of Pâleur S with the level of the Muqueuse S, of Sueur S cold and a long time of recoloration of the nails after pressure (see the article Collapsus ), a coldness of the ends, feelings of swarming, to see quantified examinations (like the catch of tension).

At a conscious person, one is often satisfied to take the radial pulse on the two sides (to evaluate frequency, regularity, force and symmetry), and one takes the pulse carotidien only if there is evil to feel the radial pulse.

At a person who does not breathe, without reaction to stimulations, the absence of the central pulses signs a table of Arrêt cardiorespiratory and led to undertake immediately a Réanimation cardiopulmonaire .

Other methods of acquisition the cardiac rhythm

Other methods that the perception of the wave of pulse can be used for the calculation of the cardiac rhythm:

method auscultatoire (listening of the heart by a Stethoscope), so reliable but does not allow by a continuous monitoring in time;
electrocardiographic method : the cyclic contraction of the cardiac muscle is secondary with a depolarization of the cellular membranes which is detected by electrodes located on the skin. The recording in time-reality in the form of layout on a scope is simple means of monitoring automated of the heart rate.
oxymetric method : noninvasive method (nontraumatic) by installation of a sensor at the end of a finger or on the ear, analyzing in real-time the variation of color of blood following its oxygenation. This variation is cyclic, synchronous cardiac rhythm.
hemodynamic method: into certain cases, one can introduce an end Cathéter into a Artère, connected to a pressure pick-up: the cyclic variation of the pressures thus measured makes it possible to calculate in real-time the cardiac rhythm.

At a patient hospitalized in intensive care, several methods are employed simultaneously: the agreement of the found figures is thus a reliable index of the good use of the various techniques which bring each one their own information, in addition to the cardiac rhythm.

The algorithms used for the automatic determination of the heart rate are containing thresholding: the going beyond of a threshold prefixed by the amplitude of the analyzed signal constitutes a “signal”, time between two “signals” allowing the calculation of the instantaneous frequency. Often, the latter is smoothed (realized) on some beats. If the signal weak, is parasitized or erratic (in this last case by anomaly of the operation of the heart), the registered frequency is distorted, being able to start wrongly, certain alarms.

Anomalies of the cardiac rhythm

These anomalies can be quantitative (too much fast or too slow) or qualitative (irregular beats, pauses…). The electrocardiogram is essential for the precise analysis of these disorders.

See:

Tachycardia: too fast pulse, higher than 100 beats per minute in an adult at rest (the “normal” pulse of an infant is approximately 120 beats per minute).
Bradycardia: too slow pulse, lower than 60 beats per minute in a nonsporting adult.
Turbid of the cardiac rhythm.

The cardiac rhythm as a risk factor

A cardiac rhythm raised at rest is correlated with a more important risk of died by Cardiovascular disease, and this, as well at the healthy subject as at the subject already reached of a cardiovascular disease. This risk factor seems to be independent of the other known factors (age, diabetes, nicotinism…). It does not seem on the other hand not shown that to be satisfied with an artificial fall of this heart rate (by drugs) can reduce the accident risk cardiac.

See too

Prompt help: cardiac assessment
Beat
Test of effort

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