European Journal of Cardio-Thoracic Surgery, Vol 3, 515-520, Copyright © 1989 by European Association for Cardio-thoracic Surgery
In vitro flow characteristics of the Jarvik-7 prosthesis with respect to filling pressure, stroke frequency, and systolic duration
J Liska and BK Semb
Department of Thoracic Surgery, Karolinska Hospital, Stockholm, Sweden.
The Jarvik-7 total artificial heart (TAH), as an implantable substitute for
the natural heart, has become the most widely used prosthesis. Although the
performance of the Jarvik-7 prosthesis has been described experimentally as
well as clinically, the interrelationship between cardiac output, filling
pressure, stroke frequency and systolic duration in a wider perspective has
not been reported. Our in vitro evaluation of the pump demonstrates the
relation between cardiac output and right filling pressure in the range of
2-17 mm Hg with a stroke frequency varying between 60-130 beats per minute
with 40% and 50% systolic duration. With respect to complete ventricular
filling, a safer and wider range of right filling pressures and stroke
frequencies could be employed to produce various cardiac output values at
50% systolic duration as compared to 40% systolic duration. When complete
diastolic filling was present, particularly with a high stroke frequency
and a low systolic duration, an increase of the left filling pressure to an
extent which in a clinical situation would probably cause pulmonary oedema,
was observed. By using a right Jarvik-7/70 ml ventricle and a left
Jarvik-7/100 ml ventricle, this buildup of the left filling pressure was
completely avoided.
