Devices: Difference between revisions

2,655 bytes added ,  14 January 2012
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** Lead failure, such as lead fracture or insulation failure
** Lead failure, such as lead fracture or insulation failure
** Lead maturation: the amplitude may abruptly decline during the first week after implantion, but these values return to the implantation values after about 6-8 weeks as the lead “matures”
** Lead maturation: the amplitude may abruptly decline during the first week after implantion, but these values return to the implantation values after about 6-8 weeks as the lead “matures”
[[File:temp.jpg|thumb|none|VB ECG Undersensing]]


* '''Oversensing:''' The pacemakers senses signals on the marker channel that do not correspond to the ECG pattern. This can be physiologic (e.g. ventricular pulse or myopotentials) or non-physiologic (e.g. lead fracture or if the lead is loose from the pacemaker pulse generator or outside interference such as TENS therapy or surgical diathermy).
[[File:temp.jpg|thumb|none|VB ECG Oversensing]]


* Oversensing: The pacemakers senses signals on the marker channel that do not correspond to the ECG pattern. This can be physiologic (e.g. ventricular pulse or myopotentials) or non-physiologic (e.g. lead fracture or if the lead is loose from the pacemaker pulse generator or outside interference such as TENS therapy or surgical diathermy).
* '''Non-capture:''' The electrical impulse is not followed by the myocardium.
This can be due to:
** Lead dislodgement
** Cardiac perforation
** Poor connection between lead and pacemaker
** Lead maturation: as the lead matures and becomes surrounded by fibrotic tissue, the threshold of stimulation decreases, which may result in non-capture
** Twiddler’s syndrome: a permanent malfunction of a pacemaker due to the patient's manipulation of the pulse generator
** Electrolyte disturbances: hyperkalemia, acidosis and alkalosis can affect the stimulation threshold
** Myocardial infarction: if a MI occurs near the tip of the head, an increase in stimulation threshold and/or non-capture can occur
** Drug therapy: e.g. flecainide can affect the stimulation threshold
** Battery depletion: if the delivered voltage is significantly reduced, advanced stages of battery depletion may result in non-capture
** Exit block: occurs when the stimulation threshold exceeds the pacemaker’s maximum output
[[File:temp.jpg|thumb|none|VB ECG Non-capture]]
 
* '''Changes in impedance:''' High lead impedance can be due to an open pacing circuit (e.g. lead is not connected to the pacemaker pulse generator or lead fracture). Low lead impedance can be due to a insulation break, which exposes the wire to body fluids which have a low resistance. Also, fluid/blood in the pacemaker header can decrease the lead impedance.
 
* '''Pacemaker syndrome:''' Pacemaker syndrome is the presence atrioventricular (AV) dissynchrony occurs after pacemaker implantation, regardless of the pacing mode. It is an iatrogenic disease that causes symptoms of fatigue, lightheadedness and hypotension. Symptoms are caused by the loss of atrial contribution to ventricular filling leading to a combination of backward and forward failure. Also atrial cannon waves can be present. In most cases treatment consists of adding an atrial lead and optimizing AV synchrony.
 
* '''Operative failures:''' Implantation related complications are:
** Pneumo/hematothorax (may require drain)
** Cardiac perforation/tamponade (may require drain)
** Pericarditis
** Lead dislodgement
** Infection: pocket infection or lead- or pacemaker pulse generator infection (may require pacemaker extraction)
** Bleeding/hematomas (may require drainage)
 
* '''Long term complications:''' Long term pacemaker related complications are:
** Erosion of the pulse generator through the skin (requires pacemaker extraction)
** Venous thrombosis (vena cava superior syndrome, deep vein thrombosis, lung embolism)


==ICD==
==ICD==
*Overzicht trials met link naar pubmed
*Overzicht trials met link naar pubmed
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