Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
RECOVERY OF ATTENUATED BAROREFLEX SENSITIVITY IN CONSCIOUS DOGS AFTERREVERSAL OF PACING-INDUCED HEART-FAILURE
Autore:
GRIMA EA; MOE GW; HOWARD RJ; ARMSTRONG PW;
Indirizzi:
UNIV TORONTO,ST MICHAELS HOSP,DEPT MED,DIV CARDIOL,SUITE 712B,30 BONDST TORONTO M5B 1W8 ON CANADA UNIV TORONTO,ST MICHAELS HOSP,DEPT MED,DIV CARDIOL TORONTO M5B 1W8 ONCANADA
Titolo Testata:
Cardiovascular Research
fascicolo: 3, volume: 28, anno: 1994,
pagine: 384 - 390
SICI:
0008-6363(1994)28:3<384:ROABSI>2.0.ZU;2-B
Fonte:
ISI
Lingua:
ENG
Soggetto:
SYMPATHETIC-NERVE ACTIVITY; BARORECEPTOR REFLEXES; TRANSPLANTATION; NOREPINEPHRINE; ABNORMALITIES; TACHYCARDIA; RECORDINGS; DIGITALIS; RESPONSES; OUTFLOW;
Keywords:
BAROREFLEX SENSITIVITY; EXPERIMENTAL HEART FAILURE; RAPID RECOVERY; CONSCIOUS DOGS; PHENYLEPHRINE; NITROPRUSSIDE; ECHOCARDIOGRAPHY; HEMODYNAMICS; NORADRENALINE; HYPERTENSION; HYPOTENSION;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
56
Recensione:
Indirizzi per estratti:
Citazione:
E.A. Grima et al., "RECOVERY OF ATTENUATED BAROREFLEX SENSITIVITY IN CONSCIOUS DOGS AFTERREVERSAL OF PACING-INDUCED HEART-FAILURE", Cardiovascular Research, 28(3), 1994, pp. 384-390

Abstract

Objective: Rapid ventricular pacing reliably induces seven congestiveheart failure in dogs, with an associated attenuation of baroreflex sensitivity. Unique to this model is the capacity for rapid recovery ofhaemodynamics and plasma noradrenaline following the cessation of pacing; however, whether baroreflex sensitivity will similarly recover isunknown. The aims of this study were (1) to assess baroreflex controlof heart rate in response to acute hypertensive and hypotensive stimuli during the development of and recovery from severe heart failure, and (2) to correlate baroreflex sensitivity with haemodynamic and echocardiographic indices and with noradrenaline concentrations. Methods: Serial assessments were performed on six dogs paced to severe heart failure and then allow to recover for four weeks. R-R interval and systolic blood pressure were monitored during administrations of phenylephrine and nitroprusside and the slope (ms.mm Hg-1) of the resultant R-R interval-systolic blood pressure relationship was used to define baroreflex sensitivity. Results: Control phenylephrine and nitroprusside derived slopes were 27.05(SD 7.88) and 17.1(11.03) ms.mm Hg-1 respectively. After one week of pacing the phenylephrine derived slope was unchanged while the nitroprusside slope tended to be attenuated. In severe heart failure, both slopes were severely attenuated, at 1.88(6.45) ms.mm Hg-1 (phenylephrine) and 4.21(3.28) ms.mm Hg-1 (nitroprusside) (bothp<0.05). Intrinsic heart rate, noradrenaline concentrations and cardiac filling pressures were raised at severe heart failure while cardiacoutput and systolic blood pressure were significantly reduced. Recovery of baroreflex control of heart rate was evident as early as 48 h following pacing cessation and was maintained after four weeks recovery. Haemodynamics, cardiac output. and noradrenaline also returned to control while cardiac dilatation persisted. Nitroprusside and phenylephrine derived slopes were inversely correlated with intrinsic heart rate and pulmonary arterial/capillary wedge pressures respectively. Conclusions: Despite marked attenuation of baroreflex control of heart rate at severe heart failure, rapid recovery was seen in response to both hypotensive and hypertensive stimuli. The speed with which recovery occurs suggests that attenuation of baroreflex sensitivity at severe heartfailure is likely to be mediated by functional alterations rather than morphological damage.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 07/07/20 alle ore 05:22:12