[Heart diseases as a cause of cerebral symptoms and syndromes]

The causes, clinical indications and diagnosis and differential diagnosis of cardiac disorders which may lead to cerebral symptoms are illustrated on the basis of a review of the present day level of scientific research. Principally involved are cerebral ischaemias arising from cerebral embolisms or from reduction of cardiac output in cardiovalvular and myocardial disorders. The incidence of all embolisms of cardiac origin makes up 10% of all ischaemic cerebral infarcts, with auricular fibrillation, irrespective of its origin, mitral stenosis, myocardial infarct, mitral insufficiency and combined mitral valve defects, and, in younger patients, mitral valve prolapse, being, in this order of frequency, of primary clinical significance. The other cardiovalvular and myocardial disorders have, in comparison, a relatively low incidence of cerebral embolisms. Haemodynamically induced cerebral ischaemias frequently occur in the form of complications following acute cardiac arrest, in myocarditis and in case of primary cardiomyopathies resulting from cardiac insufficiency or complicating bradyarrhythmia. They are clinically apparent in the form of syncope, and other impairments of consciousness of various levels of seriousness with and without indications of cerebral origin, extending up to coma. In view of the high incidence of 25% of acute cerebral ischaemias in cases of cardiac disease, not only neurological but also detailed cardiological investigation is vital in all cases for a correct diagnosis and for the selection of a suitable course of treatment. Cerebral complications in bradyarrhythmia and endocarditis are discussed in the context of a review of the relevant literature together with consideration of their epidemiology, aetiology, pathophysiology and clinical profile. Pathological sinus-bradycardia, bradyarrhythmia absoluta, sinu-atrial and atrio-ventricular blockages, carotid-sinus and sick-sinus node syndrome, paroxysmal atrial tachycardia, AV-node tachycardias, and auricular fibrillation and flutter, taken as a whole, lead to cerebral complications affected patients in 5 to 10% of afflictions of the central nervous system occur in 50% of patients suffering from complete AV blockage and, at a not precisely definable frequency, in patients suffering from other bradyarrhythmias. In addition to transitory, uncharacteristic symptoms such as dizziness, vertigo, impairment of vision and balance, presyncope, syncope and Adams-Stokes syndrome dominate the clinical profile. Endocarditis, with an incidence of 0.01 to 0.05% in the overall population, results in central nervous system complications in 12 to 25% of cases on average.(ABSTRACT TRUNCATED AT 400 WORDS)