[Consciousness disorders from cardiological view]

Consciousness disorders may have many causes, mainly cardiac arrhythmias. The incidence of bradyarrhythmias (BA) in patients with acute coronary syndrome (ACS) is 0.3-18 % and caused by sinus node dysfunction (SND), high degree atrioventricular (AV) block or bundle branch blocks. SND are sinus bradycardia or sinus arrest. 1st degree AV-block occurs in 4-13 % of patients with ACS caused by rhythm disturbances in atrium, AV node, bundle of His or the Tawara system. 1st or 2nd degree AV block is seen very frequently within 24 hours after beginning of ACS and these arrhythmias are frequently transient and no more present after 72 hours. 3rd degree AV blocks are also frequently transient in pts with infero-posterior myocardial infarction (MI) and permanent in anterior MI patients. Left anterior fascicular block occurs in 5 % of ACS, left posterior fascicular block is observed less frequently (incidence < 0.5 %). Complete bundle branch block is present in 10-15 % of ACS patients and right bundle branch block is more often (2/3) present than left bundle branch block (1/3). In patients with BA atropine i. v. (1-3 mg) is helpful in 70-80 % of ACS patients and will lead to an increased heart rate. The need of pacemaker stimulation (PS) is different in patients with inferior (IMI) or anterior MI (AMI). Tachyarrhythmias are ventricular tachycardia, ventricular flutter or ventricular fibrillation in pts with ACS and it is necessary to terminate these arrhythmias as soon as possible by direct current cardioversion or defibrillation. Other causes of consciousness disorders are valvular heart diseases (aortic stenosis, hypertrophic obstructive cardiomyopathy), myxoma or ion-channel diseases (Brugada syndrome, long and short QT-syndromes). In all cases, a detailed cardiological evaluation is necessary in order to initiate a proper treatment.