Echocardiographic assessment during exercise of heart failure patients with cardiac resynchronization therapy.
This prospective echocardiographic study investigated the respective impacts of left ventricular (LV) pacing and simultaneous and sequential biventricular pacing (BVP) on ventricular dyssynchrony during exercise in 23 patients with compensated heart failure and ventricular conduction delays. During exercise, LV pacing and BVP significantly (p <0.05) improved mitral regurgitation and LV dyssynchrony compared with spontaneous activation. LV segmental electromechanical delays were significantly prolonged during LV pacing, leading to increased systolic time (p <0.05), decreased LV filling time (p <0.05), and decreased stroke volume (p <0.05) compared with BVP. After optimization of the interventricular delay with sequential BVP, additional benefit was obtained during exercise in terms of stroke volume and mitral regurgitation (p <0.05). The optimal interventricular delay was different at rest and during exercise in 57% of the patients. Changes from at rest to exercise in LV dyssynchrony were correlated with changes in stroke volume (r = -0.61, p <0.01) and changes in mitral regurgitation (r = 0.60, p <0.01).
Bordachar
Pierre
P
Cardiologic Hospital, Pessac and Bordeaux 2 University, Pessac, France. bordacharp@hotmail.com
Lafitte
Stephane
S
Reuter
Sylvain
S
Serri
Karim
K
Garrigue
Stephane
S
Laborderie
Julien
J
Reant
Patricia
P
Jais
Pierre
P
Haissaguerre
Michel
M
Roudaut
Raymond
R
Clementy
Jacques
J
D002304:Cardiac Pacing, Artificial; D004452:Echocardiography; D004554:Electric Countershock; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005500:Follow-Up Studies; D006333:Heart Failure / Q000000981:diagnostic imaging* / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D009200:Myocardial Contraction; D011379:Prognosis; D011446:Prospective Studies