Effects of cardiac resynchronization therapy on the mechanisms underlying functional mitral regurgitation in congestive heart failure.
OBJECTIVE
Functional mitral regurgitation (FMR) improvement induced by cardiac resynchronization therapy (CRT) has been related to left ventricular (LV) remodeling reversal and contractility enhancement. The effects induced by the changes of LV synchronicity indexes on FMR severity have not been investigated.


RESULTS
In 30 patients with CRT for heart failure (HF) and QRS>130 ms, LV function parameters, FMR severity as mitral jet regurgitation/left atrial area ratio (JA/LAA) and standard deviation (SD) of the time to the systolic peak velocity at 6-basal and mid-LV segments as asynchrony indexes were evaluated (echo/tissue Doppler) before and 6 months after implant. At follow-up, 15 patients resulted responders to LV reverse remodeling with > or =15% end-systolic volume (ESV) and LV systolic function improvement. Improvement of FMR with > or =15% JA/LAA reduction was observed in 19 patients, 7 were nonresponders to LV reverse remodeling. In patients with > or =15% JA/LAA reduction a significant decrease of LV asynchrony indexes was observed as compared to patients without > or =15% JA/LAA reduction in whom LV asynchrony indexes were increased. Reduction of LV mid-segmental asynchrony was the variable most strongly related to JA/LAA reduction (r(2)=0.697, P<0.01), with good agreement between observed and predicted values (only 1 patient outside the mean+/-2SD).


CONCLUSIONS
These data reveal that CRT can reduce FMR irrespective to LV remodeling reversal; this effect is related to LV asynchrony reduction and further support CRT employment in patients with HF and FMR.
Porciani
Maria Cristina
MC
University of Florence, Institute of Internal Medicine and Cardiology, V. le Morgagni 85, 50134 Florence, Italy. cporciani@hotmail.com
Macioce
Roberto
R
Demarchi
Gabriele
G
Chiostri
Marco
M
Musilli
Nicola
N
Cappelli
Francesco
F
Lilli
Alessio
A
Ricciardi
Giuseppe
G
Padeletti
Luigi
L
D000368:Aged; D000369:Aged, 80 and over; D002304:Cardiac Pacing, Artificial; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy*; D006352:Heart Ventricles / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000503:physiopathology* / Q000628:therapy*; D009200:Myocardial Contraction; D017202:Myocardial Ischemia / Q000503:physiopathology / Q000628:therapy; D010138:Pacemaker, Artificial; D011237:Predictive Value of Tests; D011788:Quality of Life; D012044:Regression Analysis; D012720:Severity of Illness Index; D013318:Stroke Volume; D016896:Treatment Outcome; D016277:Ventricular Function, Left; D020257:Ventricular Remodeling