© 1998 by European Society of Cardiology
Copyright © 1998, European Society of Cardiology
Improvement of left ventricular function and cardiovascular neural control after endoventriculoplasty and myocardial revascularization
aMedicina Interna II, Ospedale "L. Sacco", Università di Milano, Milano, Italy
bDivisione di Cardiochirurgia, Ospedale "L. Sacco", Milano, Italy
* Corresponding author. Tel. (+39-2) 3579 9316; Fax: (+39-2) 356 4630.
Objective: To investigate the effects of endoventriculoplasty (EVP) and myocardial revascularization on left ventricular function and on sympathovagal balance modulating sinus node and vasomotor activity, we studied patients with left anterior, septal or anteroseptal ventricular aneurysm, before and after surgery. It has been demonstrated that, compared to the standard aneurismectomy, EVP associated with coronary grafting has a lower operative mortality and improves ventricular function, clinical status and prognosis. Methods: We collected pre- and post-operative echocardiographic and angiographic data to determine morphological and hemodynamic changes. The pre- and post-operative neural cardiovascular control was assessed by power spectrum analysis of heart rate and systolic arterial pressure (SAP) variabilities during rest and tilt. Results: As expected, post-operative ventricular function improved significantly: ejection fraction increased from 33±2 to 46±3% (p<0.01) when assessed by echocardiography and from 40±4 to 55±5% (p<0.01) when assessed by angiography; left ventricular end-diastolic pressure fell from 22±3 to 13±2 mmHg (p<0.05). Pre-operatively sympathovagal balance responsiveness was blunted: tilt test did not induce, in respect to resting values, any significant change in low frequency (LFRR) and high frequency (HFRR) components of RR variability (in normalized units, n.u.) and in LFSAP. Post-operatively, tilt induced significant changes in LFRR and HFRR (in n.u.), in LF/HF ratio and LFSAP in respect to resting values. The pre- and post-operative percent differences —delta %—, from rest to tilt, of LFRR, HFRR, LF/HF and LFSAP were also significantly different (p<0.01, p<0.05, p<0.05, p<0.05). In addition, we compared data obtained from survivors and non-survivors (6 out of 19 patients died within 4 months because of heart failure). Non-survivors were characterized by significantly lower RR variance (184±80 vs. 1193±309 ms2 at rest, 196±87 vs. 546±104 ms2 during tilt, p<0.05) and lower LFRR (15±7 vs. 61±6 at rest, 23±10 vs. 58±6 during tilt, in n.u., p<0.01). Conclusions: (1) The improvement of ventricular function induced by EVP and myocardial revascularization is accompanied by a restored capability to oscillate of cardiovascular neural regulatory mechanisms; (2) the drastic reduction of variance and LF component from RR variability seems to be associated with an ominous outcome.
KEYWORDS Endoventriculoplasty; Myocardial revascularization; Left ventricular function; Heart rate variability; Power spectrum analysis; Sympathovagal balance