Dynamic cardiac baroreflex responses are frequently investigated by analyzing the spontaneous reciprocal changes in arterial pressure and heart rate (HR). However, whether the spontaneous baroreflex-induced changes in HR translate into changes in cardiac output (CO) is unknown. In addition, this linkage between changes in HR and changes in CO may be different in subjects with heart failure (HF). We examined these questions using conscious dogs before and after pacing-induced HF. Spontaneous baroreflex sensitivity in the control of HR and CO was evaluated as the slopes of the linear relationships between HR or CO and left ventricular systolic pressure (LVSP) during spontaneous sequences of greater or equal to three consecutive beats when HR or CO changed inversely versus pressure. Furthermore, the translation of baroreflex HR responses into CO responses (HR-CO translation) was examined by computing the overlap between HR and CO sequences. In normal resting conditions, 44.0 +/- 4.4% of HR sequences overlapped with CO sequences, suggesting that only around half of the baroreflex HR responses cause CO responses. In HF, HR-LVSP, CO-LVSP, and the HR-CO translation significantly decreased compared with the normalcondition ( - 2.29 +/- 0.5 vs. - 5.78 +/- 0.7 beats.min(-1).mmHg(-1); - 70.95 +/- 11.8 vs. - 229.89 +/- 29.6 ml.min(-1).mmHg(-1); and 19.66 +/- 4.9 vs. 44.0 +/- 4.4%, respectively). We conclude that spontaneous baroreflex HR responses do not always cause changes in CO. In addition, HF significantly decreases HR-LVSP, CO-LVSP, and HR-CO translation.

Sala-Mercado J.A., I.M. (2008). Spontaneous baroreflex control of heart rate versus cardiac output: altered coupling in heart failure. AMERICAN JOURNAL OF PHYSIOLOGY. HEART AND CIRCULATORY PHYSIOLOGY, 294(3), H1304-H1309 [10.1152/ajpheart.01186.2007].

Spontaneous baroreflex control of heart rate versus cardiac output: altered coupling in heart failure

PALLANTE, MARCO;IELLAMO, FERDINANDO;
2008

Abstract

Dynamic cardiac baroreflex responses are frequently investigated by analyzing the spontaneous reciprocal changes in arterial pressure and heart rate (HR). However, whether the spontaneous baroreflex-induced changes in HR translate into changes in cardiac output (CO) is unknown. In addition, this linkage between changes in HR and changes in CO may be different in subjects with heart failure (HF). We examined these questions using conscious dogs before and after pacing-induced HF. Spontaneous baroreflex sensitivity in the control of HR and CO was evaluated as the slopes of the linear relationships between HR or CO and left ventricular systolic pressure (LVSP) during spontaneous sequences of greater or equal to three consecutive beats when HR or CO changed inversely versus pressure. Furthermore, the translation of baroreflex HR responses into CO responses (HR-CO translation) was examined by computing the overlap between HR and CO sequences. In normal resting conditions, 44.0 +/- 4.4% of HR sequences overlapped with CO sequences, suggesting that only around half of the baroreflex HR responses cause CO responses. In HF, HR-LVSP, CO-LVSP, and the HR-CO translation significantly decreased compared with the normalcondition ( - 2.29 +/- 0.5 vs. - 5.78 +/- 0.7 beats.min(-1).mmHg(-1); - 70.95 +/- 11.8 vs. - 229.89 +/- 29.6 ml.min(-1).mmHg(-1); and 19.66 +/- 4.9 vs. 44.0 +/- 4.4%, respectively). We conclude that spontaneous baroreflex HR responses do not always cause changes in CO. In addition, HF significantly decreases HR-LVSP, CO-LVSP, and HR-CO translation.
Pubblicato
Rilevanza internazionale
Articolo
Sì, ma tipo non specificato
Settore MED/09 - Medicina Interna
English
Con Impact Factor ISI
Arterial baroreflex sensitivity; Parasympathetic activity; Stroke volume
Sala-Mercado J.A., I.M. (2008). Spontaneous baroreflex control of heart rate versus cardiac output: altered coupling in heart failure. AMERICAN JOURNAL OF PHYSIOLOGY. HEART AND CIRCULATORY PHYSIOLOGY, 294(3), H1304-H1309 [10.1152/ajpheart.01186.2007].
Sala Mercado, Ja; Ichinose, M; Hammond, Rl; Coutsos, M; Ichinose, T; Pallante, M; Iellamo, F; O'Leary, Ds
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2108/36087
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