[Residual myocardial function in dilated myocardiopathy. Response to post-extrasystolic potentiation].

OBJECTIVE

to evaluate the effectiveness of post-extrasystolic potentiation (PESP) to detect latent residual contraction function in patients (pts) with idiopathic dilated cardiomyopathy.

DESIGN

retrospective study in pts referred for cardiac catheterization.

SETTING

Haemodynamic Laboratory of Cardiology Service, Bellvitge Hospital. Barcelona, Spain.

PATIENTS

the criteria for including pts with sinus rhythm were (SR): 1-The appearance of an extra beat R' on the ventriculogram; 2-The location of R' in relation to the preceding sinus beat R1 and the following beat R2 being such that R1-R' less than R'-R2. In patients with atrial fibrillation (AF), the criteria were: 1-An early beat Re had to be identified; 2-R1-Re interval had to be at most half of the Re-R2 interval; 3-The length of the cardiac cycle preceding R, has to be equal to the mean cycle length. All the patients with an increase of the ejection fraction (EF) from R, to R2 less than 12% were included in group A: 12 patients (3 females, 9 males, mean age 51 years, 5 SR, FE 27 +/- 10%). In group B were included patients with an increase of the ejection fraction greater than or equal to 12%; 14 patients (4 females, 10 males, mean age 50 years, 7 SR, FE = 31 +/- 7%).

MEASUREMENTS

In each ventriculogram we assessed the performance of left ventricle on R1 and R2 beats by determining: 1-Left ventricular end diastolic (EDV), end systolic (ESV), stroke (SV) volumes; 2-Volumes index (EDVI), (ESVI) (SVI); 3 - Ejection fraction (EF) - Change in ventricular contractility from R1 to R2, delta EF.

RESULTS

in the sinus rhythm group the values of R1 and R2 were respectively: EDV: (184 +/- 48 ml/m2; 191 +/- 17 ml/m2; NS); SVI (53 +/- 19 ml/m2; 80 +/- 22 ml/m2; p less than 0.01) FE (29 +/- 7%; 42 +/- 10%; p less than 0.01), delta EF 13 +/- 6%. The change of the ejection fraction from R1 to R2 in pts with SR and AF were respectively: 13 +/- 6% and 11.5 +/- 6.4%; NS. Group A: Deterioration of the functional class and two deaths occurred. Group B: Improvement in functional class in all cases but one.

CONCLUSION

our data suggest that augmented ventricular filling and consequent Starling's effect is not a significant contribute for PESP in pts with dilated cardiomyopathy. The analysis of post extrasystolic beat in SR pts and the beat following an early beat with a long diastole in AF, is a valuable method of determining the residual left ventricular function in this group of pts.