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1.
Intern Med ; 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38631852

RESUMO

Objective Frailty is common in patients with heart failure (HF). Given that gardening demands regular physical activity and offers therapeutic relaxation benefits, this activity may reduce frailty. We investigated the association between gardening activities and frailty in patients with HF. Methods, patients, or materials Between August 2022 and March 2023, we surveyed patients at risk of HF and those with HF who regularly attended a cardiology outpatient clinic. Gardening activities were defined as the ongoing cultivation of flowers, vegetables, or fruits for more than a year. The questionnaire assessed the presence or absence of gardening activities as well as the frequency, duration per session, years of experience, and scale of such activities. We calculated the frailty index. Frailty was defined as a frailty index of 0.25 or greater. Results Of the 1,277 respondents, 69% engaged in gardening and 35% were frail. After adjusting for multiple confounding factors, gardening activities showed an inverse association with frailty [odds ratio = 0.723, 95% confidence interval (0.533-0.981)]. Moreover, frailty and the frailty index showed an inverse association with more extended and large-scale gardening activities. Conclusion Gardening activities were thus found to be associated with a low prevalence of frailty in patients with HF.

2.
Heart Vessels ; 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38635061

RESUMO

Tricuspid annular enlargement in patients with atrial fibrillation (AF) can induce tricuspid regurgitation (TR). However, risk factors associated with TR progression in patients with AF have not been defined. This study aimed to clarify an association between tricuspid annular diameter (TAD) and TR progression in patients with longstanding persistent AF. We retrospectively analyzed data from 228 patients who had longstanding persistent AF for > 1 year and mild or less TR on baseline echocardiograms. We defined significant TR as moderate or greater TR, graded according to the jet area and vena contracta. The optimal cut-off value of the TAD index (TADI), based on body surface area for predicting progression to significant TR, was estimated using receiver operating characteristic (ROC) curves. The independence and incremental value of the TADI were evaluated using multivariate Cox proportional hazard regression analysis and likelihood ratio tests. Over a median follow-up of 3.7 years, 55 (24.1%) patients developed significant TR. The optimal cut-off value of 21.1 mm/m2 for the TADI at baseline and ROC curves predicted TR progression with 70.4% sensitivity and 86% specificity. Furthermore, TADI was an independent predictor of TR progression (hazard ratio, 1.32; 95% confidence interval, 1.17-1.49, P < 0.001) and had a significant incremental value that exceeded that of models constructed using clinical parameters. In conclusion, TADI was significantly associated with TR progression and was an independent predictor of TR progression in longstanding persistent AF.

3.
J Cardiol ; 82(1): 43-50, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-36898666

RESUMO

BACKGROUND: Exercise intolerance in patients with heart failure (HF) increases HF-associated readmission, and right ventricular (RV) contractile reserve assessed by low-load exercise stress echocardiography (ESE) is associated with exercise intolerance. This study investigated the impact of RV contractile reserve evaluated by low-load ESE on HF readmission. METHODS: We prospectively examined 81 consecutive patients hospitalized for HF who underwent low-load ESE under a stabilized HF condition between May 2018 and September 2020. We performed a 25-W low-load ESE and defined RV contractile reserve as the increment in RV systolic velocity (RV s'). The primary outcome was hospital readmission. Incremental values of the change in RV s' over a readmission risk (RR) score were analyzed using the receiver operating characteristic (ROC) area under the curve; internal validation using bootstrapping was performed. The association between RV contractile reserve and HF readmission was illustrated with the Kaplan-Meier curve. RESULTS: Eighteen (22 %) patients were readmitted due to worsening HF during the observation period (median 15.6 months). The cut-off value of 0.68 cm/s for the change in RV s' to predict HF readmission with the ROC curve analysis indicated good sensitivity (100 %) and specificity (76.2 %). The discriminatory ability for HF readmission was significantly improved by adding the change in RV s' to the RR score (p = 0.006), and the c-statistic using the bootstrap method was 0.92. The cumulative survival rate free of HF readmission was significantly lower in patients with reduced-RV contractile reserve (log-rank test, p < 0.001). CONCLUSIONS: The change in RV s' during low-load exercise had an incremental prognostic value for predicting HF readmission. The results demonstrated the loss of RV contractile reserve assessed by low-load ESE was associated with HF readmission.


Assuntos
Insuficiência Cardíaca , Disfunção Ventricular Direita , Humanos , Teste de Esforço/métodos , Contração Miocárdica , Readmissão do Paciente , Estudos Prospectivos , Insuficiência Cardíaca/terapia , Função Ventricular Direita , Disfunção Ventricular Direita/etiologia , Volume Sistólico
5.
Coron Artery Dis ; 30(7): 547-548, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31135405

RESUMO

BACKGROUND: Positive provoked spasm in the left circumflex artery (LCX) is lower than that in the left anterior descending artery and right coronary artery (RCA). PATIENTS AND METHODS: We examined the provoked positive spasm in the LCX between the maximal acetylcholine (ACh) 100 µg period (January 1991 to July 2012, 1474 patients: the former period) and the maximal ACh 200 µg period (August 2012 to August 2018, 336 patients: the latter period). ACh was injected in incremental dose of 20/50/100/200 µg into the left coronary artery and of 20/50/80 µg into the RCA. Positive spasm was defined as at least 90% stenosis and usual chest symptoms or ischemic ECG changes. RESULTS: Provoked positive spasm in the latter period was significantly higher than that in the former period (65.5 vs. 39.1%, P < 0.001). The positive spasm increase of RCA and left anterior descending artery was 143 and 159%, whereas the increase of LCX was 204%. Multiple-vessel spasm was also increased in the latter period. CONCLUSION: Maximal ACh dose into the left coronary artery may affect the positive spasm in the LCX and multiplevessel spasm.


Assuntos
Acetilcolina/administração & dosagem , Vasoespasmo Coronário/induzido quimicamente , Vasos Coronários/efeitos dos fármacos , Vasoconstrição/efeitos dos fármacos , Vasoconstritores/administração & dosagem , Idoso , Angiografia Coronária , Vasoespasmo Coronário/diagnóstico , Vasoespasmo Coronário/fisiopatologia , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/fisiopatologia , Relação Dose-Resposta a Droga , Eletrocardiografia , Feminino , Humanos , Injeções Intra-Arteriais , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes
6.
J Cardiol Cases ; 20(4): 118-121, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31969938

RESUMO

A 52-year-old man was transferred to our hospital for ventricular fibrillation. He had no chest symptoms until then. After his full recovery, the administration of acetylcholine 20 µg showed the multiple spasm (left main trunk/left anterior descending artery/right coronary artery) without any chest symptoms or ischemic electrocardiographic changes. Subcutaneous implantable cardioverter-defibrillator (S-ICD) was implanted because of no chest symptoms during his-daily-life. We performed the pharmacological spasm provocation tests under the abundant medications. Sequential spasm provocation test provoked just focal spasm at mid left anterior descending artery. We convinced that medications and S-ICD suppress the next fatal event. .

7.
Intern Med ; 58(1): 21-30, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30101945

RESUMO

Objectives The clinical characteristics in patients with catheter-induced spasm in the proximal right coronary artery (RCA) are controversial. We performed a clinical analysis of catheter-induced spasm in the RCA. Methods We retrospectively analyzed 5,296 consecutive patients who underwent diagnostic or follow-up angiography during a 26-year period. During this period, we found 40 patients with catheter-induced spasm in the RCA. We compared the clinical characteristics and procedures of cardiac catheterization in patients with catheter-induced spasm in the RCA with those in patients without such spasm. Results The frequency of catheter-induced spasm in the RCA was 0.75% (40/5,296). We performed pharmacological spasm provocation tests in 36 of 40 patients after spasm relief. Positive spasm was observed in 32 patients (88.9%), and 25 patients (78.1%) had multiple spasms. The catheter procedures, including the approach sites (radial/brachial/femoral), catheter size (4/5/6Fr) and catheter type (Judkins right/Sones/Shared/Judkins left 3.5/Amplatz) were not markedly different between the two groups. A multivariate analysis showed that positive spasm [odds ratio (OR): 7.030, 95% confidence interval (CI): 1.920-25.700], a younger age (OR: 0.937, 95% CI: 0.910-0.965) and diabetes mellitus (OR: 0.278, 95% CI: 0.083-0.928) were the determinant factors for the catheter-induced spasm. Conclusion Approximately 80% of patients with catheter-induced spasm in the proximal RCA had coronary spastic angina. Positive provoked spasm was the most powerful determinant factor for catheter-induced spasm.


Assuntos
Cateterismo Cardíaco/efeitos adversos , Catéteres/efeitos adversos , Vasoespasmo Coronário/etiologia , Idoso , Angina Pectoris/etiologia , Cateterismo Cardíaco/métodos , Angiografia Coronária , Vasoespasmo Coronário/diagnóstico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos
8.
Heart Vessels ; 34(5): 745-754, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30474702

RESUMO

When cardiologists diagnose patients with coronary spastic angina, Japanese Circulation Society (JCS) guidelines recommend the intracoronary injection of acetylcholine (ACh) and ergonovine (ER) as class I. However, the pharmacological difference between ACh and ER is controversial in the clinic. We performed both ACh and ER tests in the same 528 patients during 26 years. We investigated the provoked spasm configuration, spasm site, and clinical characteristics of provoked spasm between ACh and ER, retrospectively. We defined positive spasm as ≥90% luminal narrowing. Provoked positive spasm was observed in 161 right coronary arteries (RCA) including 83 ACh just positive, 35 ER just positive, and 43 both positive. In contrast, positive spasm was documented in 172 left coronary arteries (LCA) including 94 ACh just positive, 28 ER just positive, and 50 both positive. ACh provoked spasm more distally and diffusely, while ER induced spasm more proximally and totally or focally in the RCA. In the LCA, ACh provoked spasm more proximally, whereas ER induced spasm more distally. ER testing after the negative ACh tests of RCA and LCA documented new positive spasms in 10.3% (35/340) and 7.4% (28/376), respectively. Coronary artery trees may each have a sensitive receptor on each segment. We recommend the supplementary use of ACh and ER to document coronary artery spasm in the cardiac catheterization laboratory.


Assuntos
Acetilcolina/farmacologia , Angina Pectoris/induzido quimicamente , Vasoespasmo Coronário/induzido quimicamente , Ergonovina/farmacologia , Idoso , Angina Pectoris/fisiopatologia , Angiografia Coronária , Circulação Coronária , Estenose Coronária/induzido quimicamente , Estenose Coronária/fisiopatologia , Vasoespasmo Coronário/fisiopatologia , Feminino , Humanos , Incidência , Injeções Intra-Arteriais , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Vasodilatadores/farmacologia
9.
Catheter Cardiovasc Interv ; 94(1): 38-44, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30548131

RESUMO

BACKGROUND: Temporary pace maker is necessary because of transient block or bradycardia during the intracoronary acetylcholine spasm provocation tests based on the Japanese Circulation Society guidelines. OBJECTIVES: We examined the feasibility and safety of the acetylcholine spasm provocation test via the radial artery and brachial vein approach. METHODS: We tried to perform the acetylcholine spasm provocation tests in 252 patients via the radial artery and brachial vein approach procedures during 5 years. Acetylcholine was injected in incremental doses of 20/50/80 µg into the right coronary artery (RCA) and 20/50/100/200 µg into the left coronary artery (LCA). Back-up pacing rate was set at 40 beats/min. Positive spasm was defined as transient ≥90% luminal narrowing and ischemic electrocardiographic change or usual chest pain. RESULTS: The procedure success of radial artery and brachial vein access was 94.4% (238/252) and 93.3% (235/252), respectively. We performed 221 patients (87.7%) with acetylcholine tests by radial artery and brachial vein approach. We changed to the brachial approach due to the failures of radial artery access in 14 patients. We also changed to the femoral vein in 11 patients and internal jugular vein in two patients. Back-up pace maker rhythm was observed in 92.1% (232/252) of all study patients, while it was significantly higher in the RCA testing than that in the LCA tests (84.9% (191/225) vs. 52.2% (131/251), P < 0.001). No irreversible complication was found. CONCLUSIONS: We recommend the radial artery and brachial vein approach for safety and convenience when performing the acetylcholine spasm provocation tests.


Assuntos
Acetilcolina/administração & dosagem , Cateterismo Periférico , Vasoespasmo Coronário/induzido quimicamente , Vasos Coronários/efeitos dos fármacos , Testes de Função Cardíaca , Artéria Radial , Vasoconstrição/efeitos dos fármacos , Vasoconstritores/administração & dosagem , Veias , Acetilcolina/efeitos adversos , Idoso , Cateterismo Periférico/efeitos adversos , Vasoespasmo Coronário/diagnóstico por imagem , Vasoespasmo Coronário/fisiopatologia , Vasos Coronários/diagnóstico por imagem , Vasos Coronários/fisiopatologia , Estudos de Viabilidade , Feminino , Testes de Função Cardíaca/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Segurança do Paciente , Valor Preditivo dos Testes , Punções , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Vasoconstritores/efeitos adversos
10.
Intern Med ; 57(19): 2853-2857, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29780109

RESUMO

A 75-year-old man was admitted to our hospital for follow-up coronary angiography. Just after starting coronary angiography, his electrocardiogram showed ST-segment elevation in the V1-6, I, II, and aVF leads, and he fell into catastrophic cardiogenic shock. His left coronary arteriogram showed proximal total obstruction in the left anterior descending artery and proximal subtotal occlusion in the left circumflex artery. Because pulseless electrical activity arrest was recognized, cardiopulmonary support was started. After more than 15 minutes' cardiac massage, his blood pressure gradually returned to baseline. During the cardiogenic shock due to pulseless electrical activity arrest, neither ventricular fibrillation nor ventricular tachycardia was recognized.


Assuntos
Vasoespasmo Coronário/complicações , Parada Cardíaca/complicações , Choque Cardiogênico/etiologia , Idoso , Angiografia Coronária , Vasoespasmo Coronário/diagnóstico , Vasoespasmo Coronário/terapia , Eletrocardiografia , Parada Cardíaca/diagnóstico , Parada Cardíaca/terapia , Hospitalização , Humanos , Masculino , Choque Cardiogênico/diagnóstico , Choque Cardiogênico/terapia
11.
Echocardiography ; 35(8): 1138-1148, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29648690

RESUMO

PURPOSE: Hypertrophic cardiomyopathy (HCM) impairs left ventricular (LV) diastolic function leading to left atrial (LA) dilatation. Because Doppler echocardiography cannot accurately assess LV diastolic function in hearts with heterogeneous hypertrophy, assessment of LA function might be useful for risk stratification of patients with HCM. This study aimed to elucidate the impact of LA function on outcome in patients with patients. METHODS: Seventy-six patients with HCM who underwent echocardiographic and cardiac magnetic resonance imaging were retrospectively enrolled. Twenty-six control subjects were also included. Using speckle tracking echocardiography, LA function was divided into active and passive strain indices based on the timing of the second positive peak of LA strain rate that occurred during LV systole. RESULTS: Left atrial strain indices of active and passive function were significantly impaired concomitantly with increased LA volume index in HCM patients compared with controls. During follow-up (2.6 ± 1.7 years), 14 patients with HCM developed cardiac events (heart failure hospitalization or atrial fibrillation). The association of LA active strain with cardiac events was independent of and incremental to clinical and echocardiographic parameters (age, gender, E/e', LV global longitudinal strain, and LA volume index) in sequential models. Cardiac events were more frequent in HCM patients with LA active strain <20.3% than with active strain ≥20.3% (P = .01). CONCLUSION: Loss of LA active function was associated with increased cardiac events in patients with HCM.


Assuntos
Função do Átrio Esquerdo/fisiologia , Cardiomiopatia Hipertrófica/fisiopatologia , Ecocardiografia Doppler/métodos , Átrios do Coração/diagnóstico por imagem , Função Ventricular Esquerda/fisiologia , Cardiomiopatia Hipertrófica/diagnóstico , Diástole , Progressão da Doença , Feminino , Seguimentos , Átrios do Coração/fisiopatologia , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Humanos , Imagem Cinética por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Curva ROC , Estudos Retrospectivos , Sístole
12.
Am J Cardiol ; 118(8): 1158-1163, 2016 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-27553099

RESUMO

Fractional flow reserve (FFR) is widely used for the assessment of myocardial ischemia. However, it has the disadvantage of cost and invasive complication risks. We investigated the usefulness of quantitative coronary angiography-derived translesional pressure (QCA-TP) for predicting functional myocardial ischemia, using FFR as the gold standard. We retrospectively analyzed 152 coronary narrowings (98 left anterior descending arteries, 28 left circumflex arteries, and 26 right) in 132 patients with mild-severe coronary stenosis who underwent coronary angiography and FFR measurements simultaneously. QCA-TP was calculated using software implemented in the QCA software. Coronary morphology was calculated using both densitometry and lumen edges. Functional myocardial ischemia was defined as an FFR of 0.8 or less. The mean values of diameter stenosis by QCA and FFR were 48.9% ± 14.9 and 0.76 ± 0.14, respectively. QCA-TP was significantly correlated with FFR (r = 0.76, p <0.01). The cut-off values of QCA-TP for predicting functional myocardial ischemia based on FFR were 72.8 mm Hg for the left anterior descending arteries (accuracy, 86.7%; area under the curve [AUC], 0.93), 60.5 mm Hg for the left circumflex arteries (accuracy, 89.3%; AUC, 0.88), and 64.4 mm Hg for the right (accuracy, 88.5%; AUC, 0.94). Therefore, our data suggest that QCA-TP can predict myocardial ischemia with high diagnostic accuracy.


Assuntos
Pressão Sanguínea , Angiografia Coronária , Estenose Coronária/diagnóstico por imagem , Reserva Fracionada de Fluxo Miocárdico , Isquemia Miocárdica/diagnóstico por imagem , Idoso , Idoso de 80 Anos ou mais , Densitometria , Humanos , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Índice de Gravidade de Doença , Software
14.
Case Rep Ophthalmol ; 5(3): 365-72, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25520652

RESUMO

Two female patients with histories of cancer who showed cryptogenic organizing pneumonia (COP) complications and bilateral anterior uveitis with hypopyon were examined. Both patients had suffered from COP and received intermitted systemic corticosteroid administration (SCA). The first patient, a 65-year-old woman with a history of breast cancer, showed bilateral uveitis with hypopyon. The topical corticosteroid treatment was ineffective. After SCA for the treatment of COP was started, the hypopyon gradually dissipated. Upon termination of SCA, uveitis relapses were controlled by renewed SCA. The other patient, a 69-year-old woman with a history of ovarian cancer, showed bilateral anterior uveitis with hypopyon. Her intraocular outcome did not improve by the topical corticosteroid administration, but SCA that was applied to treat COP led to remission of uveitis. Imaging examinations, biochemical analysis, symptoms or HLA-B27 antigen screenings in either patient did not explain the development of uveitis. Bilateral anterior uveitis is commonly related to autoimmune disease or systemic syndrome. We report two cases with COP that developed bilateral anterior uveitis with hypopyon resistant to topical administration but responsive to systemic administration of corticosteroid. These findings suggest that COP can be associated with the etiology of anterior uveitis.

16.
J Echocardiogr ; 10(3): 109-11, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27278212

RESUMO

Resolution of the issue of nonresponsiveness to cardiac resynchronization therapy (CRT) remains crucial to the successful treatment of conduction disturbances in heart failure. In this study, a patient with refractory heart failure including left bundle branch block was treated via surgical CRT. The epicardial left ventricular (LV) lead, implanted using thoracoscopic guidance, was unexpectedly located on the apical side. Echocardiographic findings of the LV motion mimicked takotsubo cardiomyopathy. The LV lead was successfully re-implanted along a lateral branch of the cardiac vein using an endovascular approach, resulting in restored contractility and reversal of the LV remodeling.

17.
Biol Pharm Bull ; 30(7): 1344-9, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17603179

RESUMO

Bacampicillin was developed as a prodrug to improve the intestinal absorption of its metabolite ampicillin. This study was undertaken to characterize bacampicillin transport in Caco-2 cells. The uptake of bacampicillin in Caco-2 cells was significantly greater than those of ampicillin and pivampicillin. An Eadie-Hofstee plot obtained from 5-min uptake of 0.2-5 mM bacampicillin was linear, indicating the presence of a saturable transport system for bacampicillin with K(m) and V(max) of 3.6 mM and 23.9 nmol/mg protein/min, respectively. Hydrophilic organic cations such as choline, cimetidine, guanidine, nicotinamide, 1-methylnicotiamide, and tetraethylammonium failed to modulate bacampicillin uptake in Caco-2 cells whereas diphenhydramine, procainamide, and thiamine significantly depressed it. Moreover, when thiamine was preloaded in Caco-2 cells, bacampicillin uptake was significantly increased, indicating that this cationic vitamin was capable of trans-stimulating bacampicillin transport across the apical membrane of Caco-2 cells. However, trans-stimulated bacampicillin uptake was not observed in the presence of diphenhydramine. Bacampicillin uptake increased with elevation of the medium pH, and the known modulators of thiamine transport such as amiloride and oxythiamine significantly inhibited bacampicillin uptake. Thiamine also significantly decreased the apical-to-basolateral transport of bacampicillin across Caco-2 cell monolayers. However, thiamine did not exert any modulating effect on pivampicillin uptake and its apical-to-basolateral permeation in Caco-2 cells. These results suggest that bacampicillin is transported in Caco-2 cells, sharing a carrier-mediated system with thiamine.


Assuntos
Ampicilina/análogos & derivados , Antibacterianos/farmacocinética , Tiamina/metabolismo , Ampicilina/farmacocinética , Transporte Biológico/efeitos dos fármacos , Células CACO-2 , Difenidramina/farmacologia , Humanos , Concentração de Íons de Hidrogênio , Proteínas de Membrana Transportadoras/fisiologia , Transportador 1 de Peptídeos , Pivampicilina/farmacocinética , Simportadores/fisiologia , Tiamina/farmacologia
18.
Inorg Chem ; 35(11): 3335-3347, 1996 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-11666536

RESUMO

A series of mono- and dinuclear Ru(bpy)(2) complexes (bpy = 2,2'-bipyridine) containing 2,2'-bis(benzimidazol-2-yl)-4,4'-bipyridine (bbbpyH(2)) were prepared. The mononuclear complex [Ru(bpy)(2)(bbbpyH(2))](ClO(4))(2).CH(3)OH.4H(2)O was characterized by an X-ray structure determination. Crystal data are as follows: triclinic, space group P&onemacr;, a = 14.443(4) Å, b = 15.392(4) Å, c = 11.675(2)Å, alpha = 101.44(2) degrees, beta = 107.85(2) degrees, gamma = 96.36(2) degrees, V = 2380(1) Å(3), Z = 2. The coordination geometry of the ruthenium(II) ion is approximately octahedral. The dihedral angle between the two pyridyl rings in bbbpyH(2) is 9.4(3) degrees, which is close to coplanar, in the complex. Mono- and dinuclear complexes exhibit broad charge-transfer absorption bands at 420-520 nm and emission at 660-720 nm in CH(3)CN solution with lifetimes of 200-800 ns at room temperature. Transient difference absorption spectra and resonance Raman (rR) spectra were used to assign the charge-transfer bands in the 420-520 nm region and to identify the lowest excited states. Both absorption and emission spectra are sensitive to solvent and solution pH. Deprotonation of the dinuclear complex raises the energies of the pi orbitals of the bbbpyH(2) ligand, so that they become closer in energy to the pi orbitals of bpy. The intervalence band of [(bpy)(2)Ru(bbbpyH(2))Ru(bpy)(2)](5+)()()is observed at 1200 nm ( epsilon = 170 M(-)(1) cm(-)(1)) in CH(3)CN. The value of the electronic coupling matrix element, H(AB), was determined as 120 cm(-)(1). Upon deprotonation, the IT band was not observed. It is therefore concluded that a superexchange pathway occurs predominantly via the Ru(II) dpi-bbbpyH(2) pi interaction, since deprotonation decreases the interaction. The role of the intervening fragments in the bridging ligand is discussed from the viewpoint of orbital energies and their orbital mixing with Ru dpi orbitals.

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