Effects of cardiac resynchronization therapy on diastolic function: evaluation by radionuclide angiography.
While the beneficial effects of cardiac resynchronization therapy (CRT) on left ventricular (LV) systolic function have been demonstrated, no information is available regarding its effects on LV diastolic function during exercise. Using radionuclide angiography, we prospectively evaluated the effects of CRT on diastolic function at rest and during exercise in 15 patients consecutively referred for CRT. All patients underwent equilibrium Tc(99) radionuclide angiography with bicycle exercise performed (1) at baseline; (2) immediately after CRT implantation, in spontaneous rhythm and during CRT; and (3) after 3 months of biventricular stimulation. Diastolic function was assessed by measurements of peak filling rate (PFR). At baseline, activation of biventricular stimulation influenced PFR neither at rest (1.06 +/- 0.34 vs 1.07 +/- 0.50 mL/s during spontaneous rhythm, P = 0.9) nor during exercise (1.45 +/- 0.62 vs 1.33 +/- 0.48 mL/s, P = 0.3). At 3 months, improvements were observed in New York Heart Association functional class and systolic function. By contrast, no improvement in diastolic function was observed either at rest (PFR = 1.11 +/- 0.45 vs 1.07 +/- 0.50 mL/s in spontaneous rhythm at baseline, P = 0.6) or during exercise (1.23 +/- 0.50 vs 1.33 +/- 0.48 mL/s, P = 0.2). These observations indicate that the intermediate benefits conferred by CRT on LV systolic function at rest and during exercise were not accompanied by similar improvements in diastolic function.
Boriani
Giuseppe
G
Institute of Cardiology, University of Bologna, Bologna, Italy. giuseppe.boriani@unibo.it
Valzania
Cinzia
C
Fallani
Francesco
F
Biffi
Mauro
M
Martignani
Cristian
C
Saporito
Davide
D
Ziacchi
Matteo
M
Diemberger
Igor
I
Greco
Cristiano
C
Bertini
Matteo
M
Domenichini
Giulia
G
Levorato
Maurizio
M
Franchi
Roberto
R
Branzi
Angelo
A
D000368:Aged; D002304:Cardiac Pacing, Artificial; D003971:Diastole; D004562:Electrocardiography; D017079:Exercise Tolerance; D005260:Female; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D011875:Radionuclide Angiography; D016896:Treatment Outcome; D016277:Ventricular Function, Left