23593
document
Aortic valve replacement . A randomized study comparing the Björk-Shiley and Lillehei-Kaster disc valves . Late haemodynamics related to clinical results . In this study , 78 randomized patients with either Björk-Shiley ( B-S ) or Lillehei-Kaster ( L-K ) aortic disc valve prostheses were re-admitted for clinical and haemodynamic evaluation . The patients were selected that those with narrow aortic roots were over-represented . Cine-aortography was carried out in 75 patients and left ventricular catheterisation via the transseptal approach was performed in 42 . The clinical improvement was striking , although the number of patients still incapacitated was relatively large in patients with the small L-K valves ( Nos . 14 & 16 ) . Peak-to-peak and mean systolic pressure differences across the valves were significantly lower in the B-S than in the L-K valves , particularly when the small valve sizes were compared . Left ventricular end-diastolic pressure ( LVEDP ) , which was elevated in most patients before operation , decreased significantly to normal levels in the B-S group . In the L-K group , LVEDP did not decrease significantly and was on the average still above the normal level after operation , probably due to the relatively large pressure gradients . The study indicates that the L-K valves Nos . 14 & 16 in particular represents a resistance to flow that is too large to be acceptable in clinical practice .
23594
Intervention_Physical
Aortic valve replacement
23595
Outcome_Physical
Left ventricular end-diastolic pressure ( LVEDP )
23596
Participant_Sample-size
78
23597
Participant_Sample-size
75
23598
Participant_Sample-size
42