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Hemodynamics after aortic valve replacement with St. Jude Medical valve for patients with small aortic annulus and severe left ventricular hypertrophy.

BACKGROUND AND AIMS OF THE STUDY
Cardiac function after aortic valve replacement (AVR) for patients with small aortic annulus and increased left ventricular (LV) wall thickness has not been clearly defined. The study aim was to examine a potential relationship between postoperative catheterization data (or radionuclide LV cardiac function) and the size of the aortic valve ring of a small St. Jude Medical prosthesis.


METHODS
Sixty-one patients with small prosthesis (< or = 23 mm) were allocated to three groups based on the diameter of the native aortic annulus or aortic valve ring of the prosthesis (group I, 19 mm; group II, 21 mm; group III, 23 mm). Pre- and postoperative cardiac function was evaluated from catheterization data and radioisotope (RI) ventriculography.


RESULTS
There were no significant inter-group differences in preoperative pulmonary artery pressures (PAPs), total pulmonary resistance (TPR), LV ejection fraction, peak ejection rate (PER) and peak filling rate (PFR). The mean postoperative PAPs and TPR of group I were significantly elevated in ICU compared with those of groups II or III (PAP: group I, 20+/-5; group II, 17+/-4; group III, 14+/-4 mmHg; p <0.01. TPR: group I, 505+/-268; group II, 316+/-134; group III, 276+/-125 dynes.s.cm-5; p <0.05). Postoperative PAPs and TPR of group I at one month after surgery were decreased, and no significant difference was found between the three groups. Cardiac function by RI study showed that postoperative PER and PFR improved in all three groups compared with the preoperative values.


CONCLUSIONS
Postoperative reversibility of PAPs and improvement of PER and PFR in patients with a prosthesis of 19 mm or 21 mm showed that a small-sized aortic SJM valve had hemodynamic advantages. However, careful postoperative management in the ICU must be applied to patients with a small aortic annulus of 19 mm and severe concentric hypertrophy.