- Email: [email protected]
The influence of atrial mechanisms on heart rate of patients with essential hypertension.
190A
AJH-APRIL 1999-VOL. 12, NO. 4, PART 2
ASH XIV ABSTRACTS
E025
E026
EARLY
INTERACTIVE ACTION OF INSULIN AND SYMPATHETIC ACTIVITY ON THE LEFT VENTRICULAR WALL. P Palatini, S Nesbitt, L Krause, O Vriz, S Majahalme, M Michieletto, S Julius. Clinica Medica 4 - University of Padova, Padova, Italy, and Division of Hypertension, University of Michigan, Ann Arbor, Mi. A number of determinants of left ventricular (LV) hypertrophy have been described, but the results of previous studies are often contradictory. We tested the hypothesis that factors contributing to LV mass may vary according to the pathophysiologic background. The study population consisted of 111 healthy adolescents and young adults participating in the Tecumseh Offspring Study. Power spectrum density estimates of heart rate variability were obtained using an autoregressive method, and subjects were divided by cluster analysis into two groups according to low frequency (LF) and high frequency (HF) components. LV data were obtained by M-mode echocardiography. One cluster o1 38 subjects had signs of sympathetic overactivity (Group 1) with higher heart rate, LF, and LF/HF, and lower HF and total power than the rest of the group (n=73, Group 2) (all p<0.01). Blood pressure (BP), waist/hip ratio, and serum cholesterol were greater in Group 1. In subjects of Group 1, insulin emerged as the strongest univariate correlate of interventricular septum and posterior wall thicknesses (p<0.001 for both), and correlated also with LV mass (p=0.009) whereas the diastolic BP correlated only marginally with interventricular septum thickness (p=0.04). Insulin remained significantly correlated also when body mass index and other clinical variables were accounted for whereas the relationship to BP lost the significance. In the subjects of Group 2, BP was strongly correlated with LV wall thicknesses and mass by univariate analysis (p values from 0.03 to <0.001), while insulin was not. The BP correlated significantly with echocardiographic indices of LV size in multivariate analysis adjusting for body mass index and other variables. In conclusion, in subjects with heightened sympathetic activity insulin is a strong determinant of LV wall thickness and mass even when adjusted for body mass index, while in subjects with normal autonomic nervous system activity the main determinant of LV size is the hemodynamic load. Key-words: sympathetic tone, insulin, heart rate variability, left ventricular hypertrophy, hypertension.
ALTERATIONS OF LEFT VENTRICULAR FUNCTION AND STRUCTURE DURING INF TREATMENT IN HCV+ CHRONIC ACTIVE HEPATITIS (CAH). S.Carugo, L.Scandola, M.Pozzi, LRoffi, S.Massiruni, V.Pecci, l.Calchera, M.G.Gorgoglione, C.Giannattasio and G.Mancia. Cattedra di Medicina Interna, Universith degli Studi di Milano, Ospedale San Gerardo Monza, Italy. Recent studies have shown a strictly correlation between progression of liver disease and heart structural and functional changes. IFN is employed in the treatment of HCV+CAH: daily doses, increased dosage schedules, long term treatment and extended indication to cirrhotic patients have been proposed to achieve better clinical benefits but must face the possibility of increased side-effects. AIM: to asses the short term effects IFN on left ventricle structure and diastolic function. METHODS:by Echocardiography (M-B-Mode, Doppler) we assessed left ventricle (LV), ejection fraction (EF) and diastolic diameter (LVDd), posterior wall thickness (LVPWt), interventricular septum thickness (IVSt), and transmittal flow: A-wave, E-wave, with E/A ratio. 15 normotensive patients with histology proven HCV+CAH were studied at baseline (CAH 1) and at 4 months during IFN theraphy (3 Mut.i.w.) (CAH 2).15 normotensive untreated HCV+ Child A cirrhotic patients (C) were also investigated. Plasma norepinephrine, PRA and Aldosterone were assayed. RESULTS: vasoactive Hormones were normal. NORMAL CAH 1 CAH 2 C LVEF% 67,9 + 1,7 70,8 + 1,43 65,4 + 1,5 * 71,4+ 2,4 LVDd 50,6 ± 0,9 50,9 + 1,1 50,72 + 1,1 47,7± 1,8 IVSt 9 ± 0,3 10,2 ± 0,4 10,5 ± 0,4 * 11,7+ 0,5 * LVPWt 9± 4 9,3 ± 0,4 9,2 ± 0,3 9,6+ 0,3 * E:A ratio 1,2 + 0,08 1,4 ± 0,2 |,4 ± 0,2 0,83+ 0,07 • p< 0,02 CAHI vs CAI- 2,*p< 0,01 N vs C,*p< 0,0, CAH2 vs N DNCLUSIONS: Increase~ LV wall thi ness and diastolic dysfunction characterize patients with C. CAH patients have significant reduction of LVEF and a sligth increase of IVSt. An increase of inducibile Nitric Oxide synthase promoted by IFN administration could have a role in the slight changes observed in CAH 2.Wbether this is an early and transient effect due to an IFN mediated increase of cytochines is matter for further studies. Key Words: Key Words : Echocardiography,Diabetes, Pathophysiology
E027
E028
C A R O T I D W A L L S H E A R STRESS IN P A T I E N T S W I T H LEFT V E N T R I C U L A R H Y P E R T R O P H Y Y N J i a n g II, K K o h a r a 2l*, M Igase u, K H i w a d a tl*. ll2nd D e p t of I n t e r - M e a l , 2)Dept of G e r i a t r i c M e d , Ehime Univ, Ehime, Japan L o w s h e a r stress h a s b e e n s h o w n to c o n t r i b u t e to a t h e r o s c l e r o s i s as a local m e c h a n i s m . In the p r e s e n t study, we i n v e s t i g a t e d the r e l e v a n c e of w a l l s h e a r stress to left v e n t r i c u l a r h y p e r t r o p h y ( L V H ) i n p a t i e n t s w i t h r i s k factors f o r a t h e r o s c l e r o s i s . Eighty patients with risk factors for the atherosclerosis were enrolled. Intima-media t h i c k n e s s (IMT), i n t e r n a l d i m e n s i o n a n d b l o o d f l o w v e l o c i t y of c a r o t i d a r t e r y w e r e e v a l u a t e d . Wall s h e a r stress w a s c a l c u l a t e d u s i n g P o i s e u i l l e a n p a r a b o l i c m o d e l of v e l o c i t y d i s t r i b u t i o n as f o l l o w : s h e a r stress = 4 x b l o o d v i s c o s i t y x c e n t r a l l i n e f l o w velocity / internal dimension. Patients were d i v i d e d i n t o t w o g r o u p s a c c o r d i n g to t h e i r L V m a s s i n d e x ; L V H ( - ) (n=36) a n d L V H ( + ) (n=44). P a t i e n t s with LVH(+) had increased IMT and dilated common carotid arterial dimension than those with L V H ( - ) . T h e m e a n s h e a r stress a n d systolic p e a k s h e a r stress w e r e s i g n i f i c a n t l y l o w e r i n p a t i e n t s w i t h LVH(+) c o m p a r e d w i t h patients w i t h LVH(-). Furthermore, m e a n s h e a r stress (r=-0.42, p<0.0001) a n d p e a k s h e a r stress (r=-0.36, p=0.001) significan.tly r e l a t e d to L V m a s s i n d e x . Stepwise regresszon analysis revealed that IMT and LV mass index were i n d e p e n d e n t d e t e r m i n a n t s for p e a k systolic w a l l s h e a r stress as w e l l as m e a n w a l l s h e a r stress. T h e s e r e s u l t s i n d i c a t e t h a t l o w s h e a r stress c o n t r i b u t e s to a t h e r o s c l e r o s i s of l a r g e a r t e r y i n p a t i e n t s w i t h L V H .
THE INFLUENCE OF ATRIALMECHANISMSON HEART RATE OF PATIENTS WITH ESSENTIALHYPERTENSION.T. Kiira, P. lur~ik, M. Sou~ek,J. Toman,J. Hal~nek,L. ~pinarov~M. Novhk,J. ~umbera, M. ~tejla. Z. Nov&kovh, [. ~.ih~ek; Department of Cardiology. Faculty Hospital ,,Sv. Anna",Brno, CzechRepublic The intravascularvolume(IVV) increase plays an importantrole in pathophysiology of essential hypertension(EH). Most EH patients exhibit an increased heart rate (HR) at rest. This is usually associated with an increased sympatheticactivity.The aim of the study was to establish whetherIVV can by itself cause an increase in the heart rate (HR), even without an increased sympathetic tone. Test subjects: 10 patients 3 weeks to I year after a heart transplantation (HTx). Methodology: Continual recording of blood pressure (Finapres), HR, frequencyand depth of breathing(viathe originalsystemAnna. ver.l.0) at rest and at deep breathing 6 × rain.-I (simulationof increased filling atrial pressure at increased IVV). Data recording and processing: software ScopeWin ANS. Digital quadrature detection method lbr calculation of phase shifts (lags) between breathingsignals and HR. Results: A significant increase in HR at deep breathing(as comparedto breathingat rest) has been established. This is shown in the Figures below (XYt graphs), where X axis is for R-R intervals (ms), Y axis is for the breathing volume(ml) and 3rd dimension is time. Fig. A represents results of rest recordings and Fig. B results of deep breathing recording. Increased HR at deep breathing was observed lbr all subjects, as early as 3 weeksafter HTx (6 subjects).
Key Words: carotid arterial atherosclerosis, left v e n t r i c u l a r m a s s i n d e x , s h e a r stress
,o
il -10
o!o
,'o ms RR
B'
.Io
o'o
,'o ms P~
In our opinion, an 1VV may lead to an increasedexpansionof cells in the sinoatrial nodus and by doing that, it may mechanicallyinduce an increased HR. This reaction may obviously be amplified by an increased sympathetic tonus. The findings support the preferred selection of a combined therapy of patients withEH. Key Words:
atrial mechanism,heartrate, phaseshift, XYt graph
AJH-APRIL 1999-VOL. 12, NO. 4, PART 2
ASH XIV ABSTRACTS
E025
E026
EARLY
INTERACTIVE ACTION OF INSULIN AND SYMPATHETIC ACTIVITY ON THE LEFT VENTRICULAR WALL. P Palatini, S Nesbitt, L Krause, O Vriz, S Majahalme, M Michieletto, S Julius. Clinica Medica 4 - University of Padova, Padova, Italy, and Division of Hypertension, University of Michigan, Ann Arbor, Mi. A number of determinants of left ventricular (LV) hypertrophy have been described, but the results of previous studies are often contradictory. We tested the hypothesis that factors contributing to LV mass may vary according to the pathophysiologic background. The study population consisted of 111 healthy adolescents and young adults participating in the Tecumseh Offspring Study. Power spectrum density estimates of heart rate variability were obtained using an autoregressive method, and subjects were divided by cluster analysis into two groups according to low frequency (LF) and high frequency (HF) components. LV data were obtained by M-mode echocardiography. One cluster o1 38 subjects had signs of sympathetic overactivity (Group 1) with higher heart rate, LF, and LF/HF, and lower HF and total power than the rest of the group (n=73, Group 2) (all p<0.01). Blood pressure (BP), waist/hip ratio, and serum cholesterol were greater in Group 1. In subjects of Group 1, insulin emerged as the strongest univariate correlate of interventricular septum and posterior wall thicknesses (p<0.001 for both), and correlated also with LV mass (p=0.009) whereas the diastolic BP correlated only marginally with interventricular septum thickness (p=0.04). Insulin remained significantly correlated also when body mass index and other clinical variables were accounted for whereas the relationship to BP lost the significance. In the subjects of Group 2, BP was strongly correlated with LV wall thicknesses and mass by univariate analysis (p values from 0.03 to <0.001), while insulin was not. The BP correlated significantly with echocardiographic indices of LV size in multivariate analysis adjusting for body mass index and other variables. In conclusion, in subjects with heightened sympathetic activity insulin is a strong determinant of LV wall thickness and mass even when adjusted for body mass index, while in subjects with normal autonomic nervous system activity the main determinant of LV size is the hemodynamic load. Key-words: sympathetic tone, insulin, heart rate variability, left ventricular hypertrophy, hypertension.
ALTERATIONS OF LEFT VENTRICULAR FUNCTION AND STRUCTURE DURING INF TREATMENT IN HCV+ CHRONIC ACTIVE HEPATITIS (CAH). S.Carugo, L.Scandola, M.Pozzi, LRoffi, S.Massiruni, V.Pecci, l.Calchera, M.G.Gorgoglione, C.Giannattasio and G.Mancia. Cattedra di Medicina Interna, Universith degli Studi di Milano, Ospedale San Gerardo Monza, Italy. Recent studies have shown a strictly correlation between progression of liver disease and heart structural and functional changes. IFN is employed in the treatment of HCV+CAH: daily doses, increased dosage schedules, long term treatment and extended indication to cirrhotic patients have been proposed to achieve better clinical benefits but must face the possibility of increased side-effects. AIM: to asses the short term effects IFN on left ventricle structure and diastolic function. METHODS:by Echocardiography (M-B-Mode, Doppler) we assessed left ventricle (LV), ejection fraction (EF) and diastolic diameter (LVDd), posterior wall thickness (LVPWt), interventricular septum thickness (IVSt), and transmittal flow: A-wave, E-wave, with E/A ratio. 15 normotensive patients with histology proven HCV+CAH were studied at baseline (CAH 1) and at 4 months during IFN theraphy (3 Mut.i.w.) (CAH 2).15 normotensive untreated HCV+ Child A cirrhotic patients (C) were also investigated. Plasma norepinephrine, PRA and Aldosterone were assayed. RESULTS: vasoactive Hormones were normal. NORMAL CAH 1 CAH 2 C LVEF% 67,9 + 1,7 70,8 + 1,43 65,4 + 1,5 * 71,4+ 2,4 LVDd 50,6 ± 0,9 50,9 + 1,1 50,72 + 1,1 47,7± 1,8 IVSt 9 ± 0,3 10,2 ± 0,4 10,5 ± 0,4 * 11,7+ 0,5 * LVPWt 9± 4 9,3 ± 0,4 9,2 ± 0,3 9,6+ 0,3 * E:A ratio 1,2 + 0,08 1,4 ± 0,2 |,4 ± 0,2 0,83+ 0,07 • p< 0,02 CAHI vs CAI- 2,*p< 0,01 N vs C,*p< 0,0, CAH2 vs N DNCLUSIONS: Increase~ LV wall thi ness and diastolic dysfunction characterize patients with C. CAH patients have significant reduction of LVEF and a sligth increase of IVSt. An increase of inducibile Nitric Oxide synthase promoted by IFN administration could have a role in the slight changes observed in CAH 2.Wbether this is an early and transient effect due to an IFN mediated increase of cytochines is matter for further studies. Key Words: Key Words : Echocardiography,Diabetes, Pathophysiology
E027
E028
C A R O T I D W A L L S H E A R STRESS IN P A T I E N T S W I T H LEFT V E N T R I C U L A R H Y P E R T R O P H Y Y N J i a n g II, K K o h a r a 2l*, M Igase u, K H i w a d a tl*. ll2nd D e p t of I n t e r - M e a l , 2)Dept of G e r i a t r i c M e d , Ehime Univ, Ehime, Japan L o w s h e a r stress h a s b e e n s h o w n to c o n t r i b u t e to a t h e r o s c l e r o s i s as a local m e c h a n i s m . In the p r e s e n t study, we i n v e s t i g a t e d the r e l e v a n c e of w a l l s h e a r stress to left v e n t r i c u l a r h y p e r t r o p h y ( L V H ) i n p a t i e n t s w i t h r i s k factors f o r a t h e r o s c l e r o s i s . Eighty patients with risk factors for the atherosclerosis were enrolled. Intima-media t h i c k n e s s (IMT), i n t e r n a l d i m e n s i o n a n d b l o o d f l o w v e l o c i t y of c a r o t i d a r t e r y w e r e e v a l u a t e d . Wall s h e a r stress w a s c a l c u l a t e d u s i n g P o i s e u i l l e a n p a r a b o l i c m o d e l of v e l o c i t y d i s t r i b u t i o n as f o l l o w : s h e a r stress = 4 x b l o o d v i s c o s i t y x c e n t r a l l i n e f l o w velocity / internal dimension. Patients were d i v i d e d i n t o t w o g r o u p s a c c o r d i n g to t h e i r L V m a s s i n d e x ; L V H ( - ) (n=36) a n d L V H ( + ) (n=44). P a t i e n t s with LVH(+) had increased IMT and dilated common carotid arterial dimension than those with L V H ( - ) . T h e m e a n s h e a r stress a n d systolic p e a k s h e a r stress w e r e s i g n i f i c a n t l y l o w e r i n p a t i e n t s w i t h LVH(+) c o m p a r e d w i t h patients w i t h LVH(-). Furthermore, m e a n s h e a r stress (r=-0.42, p<0.0001) a n d p e a k s h e a r stress (r=-0.36, p=0.001) significan.tly r e l a t e d to L V m a s s i n d e x . Stepwise regresszon analysis revealed that IMT and LV mass index were i n d e p e n d e n t d e t e r m i n a n t s for p e a k systolic w a l l s h e a r stress as w e l l as m e a n w a l l s h e a r stress. T h e s e r e s u l t s i n d i c a t e t h a t l o w s h e a r stress c o n t r i b u t e s to a t h e r o s c l e r o s i s of l a r g e a r t e r y i n p a t i e n t s w i t h L V H .
THE INFLUENCE OF ATRIALMECHANISMSON HEART RATE OF PATIENTS WITH ESSENTIALHYPERTENSION.T. Kiira, P. lur~ik, M. Sou~ek,J. Toman,J. Hal~nek,L. ~pinarov~M. Novhk,J. ~umbera, M. ~tejla. Z. Nov&kovh, [. ~.ih~ek; Department of Cardiology. Faculty Hospital ,,Sv. Anna",Brno, CzechRepublic The intravascularvolume(IVV) increase plays an importantrole in pathophysiology of essential hypertension(EH). Most EH patients exhibit an increased heart rate (HR) at rest. This is usually associated with an increased sympatheticactivity.The aim of the study was to establish whetherIVV can by itself cause an increase in the heart rate (HR), even without an increased sympathetic tone. Test subjects: 10 patients 3 weeks to I year after a heart transplantation (HTx). Methodology: Continual recording of blood pressure (Finapres), HR, frequencyand depth of breathing(viathe originalsystemAnna. ver.l.0) at rest and at deep breathing 6 × rain.-I (simulationof increased filling atrial pressure at increased IVV). Data recording and processing: software ScopeWin ANS. Digital quadrature detection method lbr calculation of phase shifts (lags) between breathingsignals and HR. Results: A significant increase in HR at deep breathing(as comparedto breathingat rest) has been established. This is shown in the Figures below (XYt graphs), where X axis is for R-R intervals (ms), Y axis is for the breathing volume(ml) and 3rd dimension is time. Fig. A represents results of rest recordings and Fig. B results of deep breathing recording. Increased HR at deep breathing was observed lbr all subjects, as early as 3 weeksafter HTx (6 subjects).
Key Words: carotid arterial atherosclerosis, left v e n t r i c u l a r m a s s i n d e x , s h e a r stress
,o
il -10
o!o
,'o ms RR
B'
.Io
o'o
,'o ms P~
In our opinion, an 1VV may lead to an increasedexpansionof cells in the sinoatrial nodus and by doing that, it may mechanicallyinduce an increased HR. This reaction may obviously be amplified by an increased sympathetic tonus. The findings support the preferred selection of a combined therapy of patients withEH. Key Words:
atrial mechanism,heartrate, phaseshift, XYt graph