Sick sinus syndrome
The term sick sinus syndrome (synonyms: sick sinus syndrome, sinus node disease) summarizes different cardiac arrhythmias, which are based on malfunction of the sinus node and conduction of excitation in atrial level. The sick sinus syndrome usually affects people over the age of 50 and is likely in men and women with equal frequency. In Germany it was called in 2004 as an indication for 29% of the approximately 55,000 pacemaker implantations.
Cause of sick sinus syndrome is often a nonspecific cicatricial degeneration in the conduction system of the heart or a mechanical stretching of the atria. In children, it is often observed after operations in the area of the right atrium in congenital heart disease, especially after the Fontan operation (but which decreases with increasing experience).
Definition and use of the term
The term sick sinus syndrome was coined in 1962 by the American cardiologist Bernard Lown. A generally accepted definition of the sick sinus syndrome does not exist today. In theory, can be diagnosed if at least one of the typical findings was detected in the electrocardiogram:
- Inadequate sinus bradycardia without other cause,
- Sinus node arrest,
- Sinoatrial block,
- Atrial fibrillation,
- Atrial flutter and
- Supraventricular tachycardias.
Since this syndrome to be counted arrhythmias are treated differently but whose designation is unusual to the common term sick sinus syndrome. The term is generally used only in special circumstances, especially
Classification by type of arrhythmia
- Sinus arrest
- SA block
- Sinus bradycardia
- Supraventricular extra beats
- Supraventricular tachycardia
- Atrial fibrillation
- Atrial flutter
- Bradycardia -tachycardia syndrome
Causes
The most common cause of sick sinus syndrome is likely to hypertension, which leads to chronic pressure load of the atria and then the stretching of the muscular fibers.
Other causes are:
- In myocarditis
- During intoxication
- In atrial overstretching
- In hypertensive heart disease
- At Mitralklappenfehlern
- At Trikuspidalklappenfehlern.
- With pulmonary hypertension
- With constrictive pericarditis
- In coronary heart disease with circulatory disturbance of the sinus node and the atrium
- Without circulatory disorder of the sinus node and the atrium
Study opportunities
The crucial test method for detection of sick sinus syndrome is the long-term ECG. It also makes sense echocardiography. Rare necessary are an exercise ECG, a long-term measurement of blood pressure or a heart catheterization. A special, very expensive method of examination of the sick sinus syndrome is the electrophysiological study.
Therapy
Basically needs a pacemaker to be implanted with symptomatic bradycardia or pauses of more than 3 seconds at a chronic SSS, and in most cases DDD systems are used.
In addition to treating the underlying disease can be useful after pacemaker implantation beta-blockers, amiodarone, dronedarone or for maintenance of sinus rhythm.
In the acute phase should induce because of the risk, symptomatic bradycardia or pauses, omitted a negative chronotropic medication completely. Symptomatic bradycardia or incipient heart failure is 0.5 mg in the acute phase of atropine intravenously, alternatively orciprenaline intravenously 1-3 micrograms, applied. Is an enlargement of the atria and is detectable atrial fibrillation before, anticoagulation should be initiated (see coumarins ). In bradycardic forms of sick sinus syndrome, the implantation of a pacemaker is useful. A catheter ablation is now only rarely performed in the sick sinus syndrome.