Cardiac sympathetic reserve and response to cardiac resynchronization therapy.

Autor:	Cha YM; Division of Cardiovascular Diseases, Mayo Clinic, Rochester, MN 55905, USA. ycha@mayo.edu, Chareonthaitawee P, Dong YX, Kemp BJ, Oh JK, Miyazaki C, Hayes DL, Rea RF, Asirvatham SJ, Webster TL, Dalzell CM, Hodge DO, Herges RM, Yong YZ, Zhang Y, Chen PS
Jazyk:	angličtina
Zdroj:	Circulation. Heart failure [Circ Heart Fail] 2011 May; Vol. 4 (3), pp. 339-44. Date of Electronic Publication: 2011 Mar 18.
DOI:	10.1161/CIRCHEARTFAILURE.110.959858
Abstrakt:	Background: The objective of the present study was to investigate the effect of cardiac resynchronization therapy (CRT) on cardiac autonomic function. Methods and Results: This prospective study included 45 consecutive patients with heart failure who received CRT devices with defibrillator and 20 age-matched, healthy control subjects. At baseline and 3 months and 6 months after CRT, we assessed New York Heart Association (NYHA) class, 6-minute walk distance, plasma sympathetic biomarker nerve growth factor, echocardiography, heart rate variability and cardiac presynaptic sympathetic function determined by iodine 123 metaiodobenzylguanidine scintigraphy. After CRT, NYHA class improved by 1 class (P<0.001), and left ventricular ejection fraction increased by 8% (P<0.001). Along with improvement in the standard deviation of all normal-to-normal R-R intervals (85.63±31.66 ms versus 114.79±38.99 ms; P=0.004) and the standard deviation of the averaged normal-to-normal R-R intervals (82.62±23.03 ms versus 100.50±34.87 ms; P=0.004), the delayed heart/mediastinum (H/M) ratio increased (1.82 [0.58] versus 1.97 [0.59]; P=0.03), whereas the mean (SD) H/M washout rate was reduced (48% [19%] versus 37% [22%]; P=0.01). Twenty-two of 45 study patients responded to CRT, with a reduction of left ventricular end-systolic volume index >15%. Compared with nonresponders, responders had a higher delayed H/M ratio (2.11 versus 1.48; P=0.003) and lower H/M washout rate (37% versus 62%; P=0.003) at baseline. Conclusions: CRT improved sympathetic function. Cardiac sympathetic reserve may be a marker for the reversibility of failing myocardial function.
Databáze:	MEDLINE
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