After the patient has been appropriately informed:
- Chest X-ray in 2 planes
- 12-channel ECG
- Laboratory tests including coagulation values
Usually the implantation is performed under local anesthesia. The aggregate is usually placed subcutaneously on the right side, subfascial on the pectoralis major muscle. For this purpose, a 5 - 7 cm skin incision is made in Mohrenheim's pit (area of the deltoideopectoral sulcus).
For the electrode, venous access is preferably via the cephalic vein, which is usually located under the lateral border of the pectoralis major muscle (Bauch 2002), since the alternative puncture of the subclavian vein is associated with an increased complication rate of between 0.7 - 2.8% (Fröhlig 2006).
In AAI, the lead is placed in the right atrial auricle (Schiergens 2018), whereas in VVI it is anchored at the base or tip of the ventricle (Bob 2001).
- 1st Atrial Demand Pacemaker (AAI).
Indications:
- Diseases of the sinus node with intact AV- conduction.
- SA blockages
However, bradyarrhythmia in intermittent atrial fibrillation should not exist (Herold 2022).
Contraindications:
- AV blockages
- Atrial fibrillation (Fischer 2013)
Advantages:
- HZV is preserved (Herold 2022) and can be increased up to 20% in some cases (Greten 2010).
- 2. ventricular demand pacemaker (VVI)
The VVI stimulates independently of the atrial rhythm (Gazarek 2019).
It can also be implanted without an electrode in certain cases - such as occlusion of the venous access, problems with the pouch due to e.g. cachexia or dementia, increased risk of infection, etc. (Glikson 2021) - as a so-called "leadless pacer" (Herold 2022). An example of this is the Micra transcatheter pacemaker system from Medtronic (El- Chami 2020).
Indications:
- Bradyarrhythmia in atrial fibrillation (Herold 2022)
- in rare cases of asystole (AV or SA block [Ebert 2005]).
Disadvantages:
- Unpleasant palpitations with possible reflex drop in blood pressure.
These occur in about 20% of VVI carriers and are called "pacemaker syndrome". It results from the non-physiological stimulation (Herold 2022).
- Aggravation of preexisting heart failure
- Worsening of the HZV (Herold 2022)