2
|
Wang X, Wu J, Zhu D, You J, Zou Y, Qian J, Ge J. Characterization of coronary flow reserve and left ventricular remodeling in a mouse model of chronic aortic regurgitation with carvedilol intervention. JOURNAL OF ULTRASOUND IN MEDICINE : OFFICIAL JOURNAL OF THE AMERICAN INSTITUTE OF ULTRASOUND IN MEDICINE 2015; 34:483-493. [PMID: 25715369 DOI: 10.7863/ultra.34.3.483] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
OBJECTIVES We hypothesized that left ventricular (LV) remodeling might be exaggerated by an impaired coronary flow reserve in mice with chronic severe aortic regurgitation, and carvedilol, a β-adrenoceptor blocker, could regress the course. METHODS Severe aortic regurgitation was induced by retrograde puncture of the aortic valve leaflets under sonographic guidance in 12-week-old male C57BL/6J mice. Four weeks after regurgitation, the mice were treated with carvedilol (30 mg/kg/d) or not treated (control). Before and 4 weeks after carvedilol treatment, the coronary flow reserve and LV structure and function were evaluated by echocardiography. Cardiomyocytes and fibrosis were validated by histologic analysis. RESULTS Four-week aortic regurgitation caused a decreased LV ejection fraction and an increased LV end-systolic volume index. Regurgitation also impaired the coronary flow reserve due to an increase in the basal coronary peak diastolic velocity and velocity-time integral combined with the absence of substantial changes in the hyperemic coronary peak diastolic velocity and velocity-time integral. Four more weeks of regurgitation further deteriorated LV remodeling and coronary perfusion in the control group. In contrast, the carvedilol-treated group showed attenuated LV remodeling and a higher coronary flow reserve by decreasing the basal peak diastolic velocity and velocity-time integral without substantial changes in the hyperemic peak diastolic velocity and velocity-time integral. The coronary flow reserve and its pretreatment versus posttreatment difference were positively correlated with the pretreatment versus posttreatment LV ejection fraction and end-systolic volume index differences. In the carvedilol-treated group, subendocardial fibrosis was significantly reduced (P < .05), and the cardiomyocyte cross-sectional area tended to be smaller. CONCLUSIONS In mice with chronic severe aortic regurgitation, carvedilol therapy significantly improves the impaired coronary flow reserve and sufficiently attenuates adverse LV remodeling. Sustained coronary flow reserve impairment indicates progressive LV remodeling.
Collapse
Affiliation(s)
- Xiangfei Wang
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China (X.W., J.W., J.Y., Y.Z., J.Q., J.G.); Department of Physiology, University of Toronto, Toronto, Ontario, Canada (J.W.); and Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China (D.Z.)
| | - Jian Wu
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China (X.W., J.W., J.Y., Y.Z., J.Q., J.G.); Department of Physiology, University of Toronto, Toronto, Ontario, Canada (J.W.); and Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China (D.Z.)
| | - Dan Zhu
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China (X.W., J.W., J.Y., Y.Z., J.Q., J.G.); Department of Physiology, University of Toronto, Toronto, Ontario, Canada (J.W.); and Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China (D.Z.)
| | - Jieyun You
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China (X.W., J.W., J.Y., Y.Z., J.Q., J.G.); Department of Physiology, University of Toronto, Toronto, Ontario, Canada (J.W.); and Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China (D.Z.)
| | - Yunzeng Zou
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China (X.W., J.W., J.Y., Y.Z., J.Q., J.G.); Department of Physiology, University of Toronto, Toronto, Ontario, Canada (J.W.); and Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China (D.Z.)
| | - Juying Qian
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China (X.W., J.W., J.Y., Y.Z., J.Q., J.G.); Department of Physiology, University of Toronto, Toronto, Ontario, Canada (J.W.); and Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China (D.Z.)
| | - Junbo Ge
- Department of Cardiology, Shanghai Institute of Cardiovascular Diseases, Zhongshan Hospital, Fudan University, Shanghai, China (X.W., J.W., J.Y., Y.Z., J.Q., J.G.); Department of Physiology, University of Toronto, Toronto, Ontario, Canada (J.W.); and Shanghai Chest Hospital, Shanghai Jiaotong University, Shanghai, China (D.Z.).
| |
Collapse
|
3
|
Rabkin SW. Differences in coronary blood flow in aortic regurgitation and systemic arterial hypertension have implications for diastolic blood pressure targets: a systematic review and meta-analysis. Clin Cardiol 2013; 36:728-36. [PMID: 24037941 DOI: 10.1002/clc.22194] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 07/09/2013] [Indexed: 11/06/2022] Open
Abstract
The objective was to evaluate coronary blood flow (CBF) in patients with systemic arterial hypertension (HTN) and to compare it with CBF in patients with aortic regurgitation (AR). A systematic literature search was conducted using the reference terms "coronary blood flow" and either "aortic regurgitation" or "hypertension." The selection criteria included CBF measurement in a concomitant control group, except studies evaluating CBF with aortic-valve replacement surgery. Twenty-two studies met the inclusion criteria. There were 318 persons with HTN, with 185 controls; and 102 persons with AR, with 144 controls. Despite an overall increase in CBF in HTN, CBF per gram of left ventricular mass was significantly (P < 0.0001) reduced. In contrast, CBF per gram of left ventricular mass was significantly (P = 0.004) increased in AR. Aortic regurgitation was associated with a significant (P < 0.0001) increase in CBF during systole and away from diastole, in contrast to persons with HTN. Aortic-valve replacement reversed the increase in systolic CBF. These data suggest that patients with HTN are more vulnerable than patients with AR to lower diastolic blood pressure (DBP), because resting CBF is compromised in HTN. Furthermore, patients with HTN may not compensate for DBP reductions by shifting CBF to systole, such as can occur with the low DBP in AR. Lower DBP in patients with AR cannot be used to justify treating patients with HTN to similar DBP because of the dramatic differences in CBF between the 2 conditions.
Collapse
Affiliation(s)
- Simon W Rabkin
- Division of Cardiology, Department of Medicine, University of British Columbia, Vancouver, British Columbia, Canada
| |
Collapse
|
4
|
Aksoy S, Cam N, Guney MR, Gurkan U, Oz D, Poyraz E, Eksik A, Agirbasli M. Myocardial Ischemia in Severe Aortic Regurgitation Despite Angiographically Normal Coronary Arteries. TOHOKU J EXP MED 2012; 226:69-73. [DOI: 10.1620/tjem.226.69] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Sukru Aksoy
- Department of Cardiology, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital
| | - Nese Cam
- Department of Cardiology, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital
| | - Mehmet Rasit Guney
- Department of Cardiovascular Surgery, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital
| | - Ufuk Gurkan
- Department of Cardiology, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital
| | - Dilaver Oz
- Department of Cardiology, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital
| | - Esra Poyraz
- Department of Cardiology, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital
| | - Abdurrahman Eksik
- Department of Cardiology, Dr. Siyami Ersek Thoracic and Cardiovascular Surgery Training and Research Hospital
| | - Mehmet Agirbasli
- Department of Cardiology, Marmara University, Faculty of Medicine
| |
Collapse
|
5
|
Plante E, Couet J, Gaudreau M, Dumas MP, Drolet MC, Arsenault M. Left ventricular response to sustained volume overload from chronic aortic valve regurgitation in rats. J Card Fail 2003; 9:128-40. [PMID: 12751134 DOI: 10.1054/jcaf.2003.17] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVES Aortic regurgitation (AR) induces left ventricular (LV) eccentric hypertrophy in response to chronic volume overload. Patients suffering from this disease often remain asymptomatic for decades before progressive LV dysfunction develops silently. Because of this slow evolution, large clinical trials with long-term follow-up on subjects with chronic AR are hard to perform. To overcome this problem, animal models have been developed in the past but results were very heterogeneous. METHODS Helped by echocardiography, we refined a known technique to induce homogeneous degrees of severe AR in Wistar-Kyoto rats. The effects on LV function without treatment and with nifedipine (25 mg/kg daily) (a drug currently recommended in humans with chronic AR) were evaluated by echocardiography. RESULTS Over 6 months, nontreated animals developed progressive LV dilatation and eccentric hypertrophy, characteristic of chronic LV volume overload. The animals also developed progressive LV systolic dysfunction, mimicking closely the evolution of the disease in humans. Abnormal filling parameters were also detected in the majority of animals. Systolic and diastolic abnormalities were prevented but only partially in the group treated with nifedipine. CONCLUSION This model can be used to study chronic AR and LV dysfunction associated with the disease. Nifedipine seems to protect the LV against chronic volume overload but only partially. Treatment strategies currently used in humans deserve further investigation.
Collapse
Affiliation(s)
- Eric Plante
- Centre de Recherche Hôpital Laval, Institut de Cardiologie de Québec, Université Laval, Quebec City, Canada
| | | | | | | | | | | |
Collapse
|
6
|
Tamborini G, Maltagliati A, Trupiano L, Berna G, Sisillo E, Salvi L, Pepi M. Lowering of blood pressure and coronary blood flow in isolated systolic hypertension. Coron Artery Dis 2001; 12:259-65. [PMID: 11428534 DOI: 10.1097/00019501-200106000-00001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND In essential hypertension, the lower limit of autoregulation of coronary flow shifts to higher perfusion and the hypertensive ventricle is at a higher than normal risk of ischemia, and less able to tolerate acute reduction of coronary perfusion pressure. Little is known about pattern of coronary flow in isolated systolic hypertension, a pathologic condition in which the elevated systolic blood pressure is associated with a lower than normal vascular compliance and normal or slightly greater than normal mean arterial pressure and vascular resistance. OBJECTIVE To evaluate the effects of rapid normalization of blood pressure on coronary blood flow in isolated systolic hypertension. METHODS We subjected 20 patients with isolated systolic hypertension to intraoperative hemodynamic and transesophageal echocardiographic monitoring during peripheral vascular surgery. Coronary flow velocity integrals and diameters in the left anterior descending coronary artery were evaluated under baseline conditions and after normalization of blood pressure, which occurred spontaneously during anesthesia (10 cases; group 1A) or was induced by infusion of nitrate (10 cases, group 1B). RESULTS After normalization of systolic blood pressure integrals decreased significantly only for patients in group 1A; percentage changes of diameter were significantly greater for patients in group 1B. Therefore, coronary blood flow after normalization of systolic blood pressure increased for patients in group 1B (by 28+/-25%) and decreased for patients in group 1A (by 30+/-21%). Changes in integrals were inversely related to those in diameter (r= -0.72, P < 0.001); for patients in group 1A changes in coronary perfusion pressure and diameter were related to those of integrals (r= 0.94; P < 0.0005). CONCLUSIONS In isolated systolic hypertension, despite there being similar changes of the systolic blood pressure, administration of nitrates caused a marked increase of coronary flow through direct effects on coronary circulation, whereas spontaneous normotension was associated with a significant reduction of coronary flow.
Collapse
Affiliation(s)
- G Tamborini
- Centro Cardiologico, Fondazione Monzino, IRCCS, Centro di Studio per le Ricerche Cardiovascolari del CNR, Milan, Italy.
| | | | | | | | | | | | | |
Collapse
|