In vitro flow characteristics of the Jarvik-7 prosthesis with respect to filling pressure, stroke frequency, and systolic duration.
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.
Liska
J
J
Department of Thoracic Surgery, Karolinska Hospital, Stockholm, Sweden.
Semb
B K
BK
D001794:Blood Pressure; D003971:Diastole; D004867:Equipment Design; D005069:Evaluation Studies as Topic; D006339:Heart Rate; D006354:Heart, Artificial / Q000009:adverse effects / Q000592:standards*; D006801:Humans; D009200:Myocardial Contraction; D011654:Pulmonary Edema / Q000209:etiology; D013318:Stroke Volume; D013599:Systole; D013997:Time Factors