Cardiac impairment evaluated by transesophageal echocardiography and invasive measurements in rats undergoing sinoaortic denervation.
BACKGROUND
Sympathetic hyperactivity may be related to left ventricular (LV) dysfunction and baro- and chemoreflex impairment in hypertension. However, cardiac function, regarding the association of hypertension and baroreflex dysfunction, has not been previously evaluated by transesophageal echocardiography (TEE) using intracardiac echocardiographic catheter.


RESULTS
We evaluated exercise tests, baroreflex sensitivity and cardiovascular autonomic control, cardiac function, and biventricular invasive pressures in rats 10 weeks after sinoaortic denervation (SAD). The rats (n = 32) were divided into 4 groups: 16 Wistar (W) with (n = 8) or without SAD (n = 8) and 16 spontaneously hypertensive rats (SHR) with (n = 8) or without SAD (SHRSAD) (n = 8). Blood pressure (BP) and heart rate (HR) did not change between the groups with or without SAD; however, compared to W, SHR groups had higher BP levels and BP variability was increased. Exercise testing showed that SHR had better functional capacity compared to SAD and SHRSAD. Echocardiography showed left ventricular (LV) concentric hypertrophy; segmental systolic and diastolic biventricular dysfunction; indirect signals of pulmonary arterial hypertension, mostly evident in SHRSAD. The end-diastolic right ventricular (RV) pressure increased in all groups compared to W, and the end-diastolic LV pressure increased in SHR and SHRSAD groups compared to W, and in SHRSAD compared to SAD.


CONCLUSIONS
Our results suggest that baroreflex dysfunction impairs cardiac function, and increases pulmonary artery pressure, supporting a role for baroreflex dysfunction in the pathogenesis of hypertensive cardiac disease. Moreover, TEE is a useful and feasible noninvasive technique that allows the assessment of cardiac function, particularly RV indices in this model of cardiac disease.
Cardiomyopathy Unit of the Heart Institute (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil; Hypertension Unit of the Heart Institute (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
Raquel A
RA
Sirvente
Hypertension Unit of the Heart Institute (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
Maria C
MC
Irigoyen
Hypertension Unit of the Heart Institute (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
Leandro E
LE
Souza
Hypertension Unit of the Heart Institute (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
Cristiano
C
Mostarda
Hypertension Unit of the Heart Institute (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
Raquel N
RN
La Fuente
Hypertension Unit of the Heart Institute (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
Georgia O
GO
Candido
Hypertension Unit of the Heart Institute (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
Pamella R M
PR
Souza
Federal University of São Paulo, Biosciences Department, Santos, São Paulo, Brazil.
Alessandra
A
Medeiros
Cardiomyopathy Unit of the Heart Institute (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
Charles
C
Mady
Cardiomyopathy Unit of the Heart Institute (InCor) do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil.
Vera M C
VM
Salemi
D000818:Animals; D017763:Autonomic Denervation; D017704:Baroreflex; D001794:Blood Pressure; D017548:Echocardiography, Transesophageal; D005080:Exercise Test; D005726:Ganglia, Parasympathetic / Q000503:physiopathology / Q000601:surgery; D006321:Heart / Q000503:physiopathology*; D006339:Heart Rate; D006973:Hypertension / Q000000981:diagnostic imaging / Q000503:physiopathology*; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D011311:Pressoreceptors / Q000000981:diagnostic imaging / Q000503:physiopathology; D011651:Pulmonary Artery / Q000000981:diagnostic imaging / Q000503:physiopathology*; D051381:Rats; D011918:Rats, Inbred SHR; D017208:Rats, Wistar; D012850:Sinus of Valsalva / Q000000981:diagnostic imaging / Q000294:innervation / Q000503:physiopathology*; D018754:Ventricular Dysfunction / Q000000981:diagnostic imaging / Q000503:physiopathology*