TRIPLE-SITE BIVENTRICULAR PACING: A NEW APPROACH FOR CARDIAC RESYNCHRONIZATION THERAPY?
A. Magalhães, P. Marques, A. Bernardes, D. Silva, P. Carrilho-Ferreira, A. Nunes Diogo, J. Sousa
Cardiology Department, Hospital de Santa Maria, Lisbon, Portugal
Introduction: Since a significant proportion of patients (pts) fail to respond to CRT, using alternative multi-site ventricular pacing strategies may provide incremental benefit. We aimed to investigate the acute effects of a triple-site biventricular pacing system in hemodynamic and ventricular dyssynchrony.
Methods: Cohort study of pts with permanent atrial fibrillation eligible for CRT. A TriVentricular (TriV) device was implanted with 2 RV leads in the apex (RA) and septum (IVS) and 1 LV lead, connected to atrial, RV and LV outputs in the generator. Echocardiography was performed during TriV, RA+LV, IVS+LV and RA+IVS configurations.
Results: Four pts were studied,70-85 years, EF 20±5%.Pts improved by at least 1 NYHA class and there were no ventricular arrhythmias or hospitalizations. Comparing the 4 configurations, there were significant differences in hemodynamic parameters as well as in interventricular dyssynchrony and septal to lateral wall motion delay (S-LWMD). There was a trend towards greater CO and SV with TriV comparing with IVS+LV mode (p=0.066). S-LWMD was lower in TriV than in RA+LV (p=0.068).
Conclusions: TriV system is feasible, secure and a promising approach for CRT in selected pts.
| Variables
|
TriV
|
RA+LV
|
IVS+LV
|
RA+IVS
|
P-value
|
| CO (L/min) |
3.45±0.58 |
3.38±0.85 |
3.10±0.86 |
2.90±0.97 |
0.012 |
| SV (mL) |
46.0±7.7 |
44.5±11.1 |
41.8±11.3 |
39.5±12.3 |
0.016 |
| MR – vena contracta (mm) |
3.0±1.7 |
3.6±1.5 |
3.6±2.1 |
4.4±1.2 |
NS |
| dPdT (mmHg) |
753±112 |
735±113 |
742±95 |
622±88 |
0.059 |
| EF (%) |
24±4 |
23±5 |
23±4 |
21±4 |
NS |
| Interventricular mechanical delay (ms) |
21±11 |
23±17 |
22±13 |
39±19 |
p0.048 |
| Septal-lateral wall motion delay (ms) |
46±17 |
80±32 |
67±49 |
101±41 |
0.077 |
| Anterior-inferior wall motion delay (ms) |
67±8 |
70±37 |
67±4 |
92±44 |
NS |
| Septal-posterior wall motion delay (ms) |
59±31 |
75±20 |
71±58 |
80±18 |
NS |
CO – cardiac ouput; SV – stroke volume; MR – mitral regurgitation; EF – ejection fraction; RA – right ventricular apex; IVS – interventricular septum; LV – left ventricle
