[Hypoperfusion of the brain in cardiac rhythm disorders]. / Hypoperfuze mozku pri poruchách srdecního rytmu.

In 134 patients (age 41-74 years) with symptoms of a transient ischaemic attack the authors made an ultrasonic dopplerometric examination of the main arteries of the head and a rheoencephalographic examination using the method of polygraphic recording with an ECG tracing II. st. 1. as well as in extreme position of the head and neck. In the investigated group in seven subjects a severe disorder of the cardiac rhythm was recorded with more than one third of ectopic ventricular contractions. The authors elaborated criteria for the objective expression of the impact of haemodynamic changes on the cerebral circulation. When doing so, they took into account the number of inadequate ventricular contractions with a pulse deficit in the periphery, the frequency of inadequate contractions and their haemodynamic effect the consequence of which was reduction of the pulse volume and slowing down of the blood flow. According to these criteria dysrhythmia was the cause of cerebral ischaemia in 4.5% of all subjects included in the authors' group. In the group of patients with a severe disorder of the cardiac rhythm dysrhythmia was the cause of a transient ischaemic attack in 86% of the patients. Trespassing of the ischaemic threshold is promoted also by a poorer blood supply in extreme positions of the head and neck which may occur in everyday life or during sleep.

[Compression of the vertebral arteries and cerebral blood supply in extreme positions of the head]. / Komprese vertebrálních cév a prokrvení mozku pri extrémních polohách hlavy.

The author investigated intracranial haemodynamics in extreme positions of the head in 320 patients (age 10 to 79 years) with symptoms of transient ischaemic attacks (TIA). From the reduction of the rheoencephalographic amplitude (REG) he concluded that in 17% of the total number of patients a significant reduction of the pulsation filling in the intracranial area of the head was present, mainly due to compression of vertebral arteries. In 33% of the subjects the period of the pulse wave was prolonged in one half of the head, in 56% there was congestion of the venous blood. In 12% of the patients the intracranial steal phenomenon was found. The majority of haemodynamic aberrations was on the homolateral side of the head in relation to the direction of the face. The greatest proportion of impaired cerebral haemodynamics was in the 7th and 8th decade; a significant reduction of the amplitude was recorded in 25%, the steal phenomenon in 27% of the patients. Disorders occur, however, also in young subjects. It may be assumed that intracranial disorders of haemodynamics are more frequent in subjects with sclerotic affections of the cerebral arteries and with congenital vascular anomalies. The incidence of disorders in young subjects can be explained by a greater extent of mobility which increases the possibility of compression of vertebral arteries. Tests involving REG examination during extreme positions of the head and neck are important for the elucidation of the aetiology of clinical symptoms of TIA and their application is useful for routine practice.