Vasis type 2B

The behaviour of blood pressure during the pre-syncopal phase is indistinguishable from that observed in patients with a negative response and, therefore, it reflects a rapid and full compensatory reflex adaptation to the upright position. This results in a rapid stabilisation of blood pressure values shortly after the assumption of the upright position. Compared to the supine position, heart rate slightly increases during this phase and stroke volume remains stable. The onset of the syncopal phase can easily be determined at the time of an abrupt fall in blood pressure which coincides with the decrease in heart rate and total peripheral resistance. Asystole occurs for more than 3 seconds.