The cardiology exams

THE IMPLANTATION OF A PACEMAKER
(and of an AUTOMATIC IMPLANTABLE DEFIBRILLATOR)

- A few explanations
- Mode and principle of the cardiac stimulation
- Implantation of the cardiac pacemaker
- Possible complications
- Your cardiac pacemaker carrier's follow-up
- What can cause your cardiac pacemaker to malfunction

A cardiac pacemaker (or pacemaker) is aimed at sending an electric impulse to the heart, which provokes its contraction.

The size of the cardiac stimulation cases has been reduced because of the significant progresses achieved in the electronics field, which improves the comfort of patients with a cardiac pacemaker.

A FEW EXPLANATIONS

An electric nervous impulse is indispensable so that the heart muscle (the myocardium) contracts.

Thus, at the normal state, a nervous impulse is naturally created by the heart and crossesthe different cavities, atria and ventricles, so that their contractions are synchronized. This nervous impulse is born in top of the rightatriumthen firstcrosses the atria, which first contractinorder to send blood into the ventricles, whose contraction is responsible for the ejection of blood into the arteries.

The arrival of the electric current by the nervous tissue induces a contraction of the heart muscle.

In the case in which this nervous impulse could not normally travel through the heart, the patient can present a loss of consciousness, a syncope, or a sudden death.

Implanting a cardiac pacemaker is aimed at provoking a contraction of the heart muscle thanks to an electric impulse. A cardiac stimulation can be necessary in the atrium when the nervous impulse is blocked up in this place, or between the atrium and the ventricle (at the level of an area named the atrioventricular node), or in the ventricle.

Before implanting the pacemaker, the heart beats very slowly in most cases, which provokes a loss of knowledge or a syncope capable of dragging some sometimes-traumatic falls.

These disorders sometimes obligethe physicians to place a temporary stimulation probe into the heart, in order to avoid the recidivations.

But sometimes, the symptoms are not as demonstrative and the patient can complain solely about weariness and empty head sensation. In these cases, an electrocardiogram permits to observe conduction anomalies of the nervous impulse in the heart.

Indeed, the electrocardiogram can show conduction anomalies of the nervous impulse in the heart, either on occasion of a sporadic recording, or on occasion of a 24 or 48 hours electrocardiogram recording (electrocardiograph Holter).

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File last reviewed on dec 18, 2011