Surgical ventricular restoration in patients with ischemic dilated cardiomyopathy: evaluation of systolic and diastolic ventricular function, wall stress, dyssynchrony, and mechanical efficiency by pressure-volume loops.
OBJECTIVE
Surgical ventricular restoration aims at improving cardiac function by normalization of left ventricular shape and size. Recent studies indicate that surgical ventricular restoration is highly effective with an excellent 5-year outcome in patients with ischemic dilated cardiomyopathy. We used pressure-volume analysis to investigate acute changes in systolic and diastolic left ventricular function, mechanical dyssynchrony and efficiency, and wall stress.


METHODS
In 3 patient groups (total, n = 33), pressure-volume loops were measured by conductance catheter before and after surgery. The main study group consisted of 10 patients with ischemic dilated cardiomyopathy (New York Heart Association class III/IV, left ventricular ejection fraction <30%) who had surgical ventricular restoration and coronary artery bypass grafting. In this group, 7 patients had additional restrictive mitral annuloplasty. To assess potential confounding effects of restrictive mitral annuloplasty and cardiopulmonary bypass, we included a group of 10 patients (New York Heart Association class III/IV, left ventricular ejection fraction <30%) who had isolated restrictive mitral annuloplasty and a group of 13 patients with preserved left ventricular function who had isolated coronary artery bypass grafting.


RESULTS
After surgical ventricular restoration, end-diastolic and end-systolic volumes were reduced from 211 +/- 54 to 169 +/- 34 mL (P = .03) and from 147 +/- 41 to 110 +/- 59 mL (P = .04), respectively. Left ventricular ejection fraction (from 27% +/- 7% to 37% +/- 13%, P = .04) and end-systolic elastance (from 1.12 +/- 0.71 to 1.57 +/- 0.63 mm Hg/mL, P = .03) improved. Peak wall stress (from 358 +/- 108 to 244 +/- 79 mm Hg, P < .01) and mechanical dyssynchrony (from 26% +/- 4% to 19% +/- 6%, P < .01) were reduced, whereas mechanical efficiency improved (from 0.34 +/- 13 to 0.49 +/- 0.14, P = .03). End-diastolic pressure increased (from 13 +/- 6 to 20 +/- 5 mm Hg, P < .01), whereas the diastolic chamber stiffness constant tended to be increased (from 0.021 +/- 0.009 to 0.037 +/- 0.021 mL(-1), NS).


CONCLUSIONS
Surgical ventricular restoration achieves normalization of left ventricular volumes and improves systolic function and mechanical efficiency by reducing left ventricular wall stress and mechanical dyssynchrony.
Tulner
Sven A F
SA
Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.
Steendijk
Paul
P
Klautz
Robert J M
RJ
Bax
Jeroen J
JJ
Schalij
Martin J
MJ
van der Wall
Ernst E
EE
Dion
Robert A E
RA
D001696:Biomechanical Phenomena; D006348:Cardiac Surgical Procedures / Q000379:methods; D002311:Cardiomyopathy, Dilated / Q000209:etiology / Q000503:physiopathology* / Q000601:surgery*; D003971:Diastole; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia / Q000150:complications; D011312:Pressure; D013599:Systole; D016276:Ventricular Function