Morphometric investigation of human myocardium in arterial hypertension and valvular aortic stenosis

Schwartzkopff, B.; Frenzel, H; Diekerhoff, J.; Betz, P.; Flaßhove, Michael; Schulte, H. D.; Mundhenke, M.; Motz, W.; Strauer, B. E.

doi:10.1093/eurheartj/13.suppl_d.17

Cited by 103 publications

(51 citation statements)

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“…Intramural coronary vessels of patients with LVH attributable to AS, however, do not show evidence of vascular remodelling. 4 We have demonstrated that functional vascular compressive forces produced by an increase in LV filling pressure (extravascular resistance) and reduction in hyperemic diastolic perfusion limit MBF in those patients with AS. 2 It is hypothesized that increased extravascular resistance leads to deformation of vessels in the myocardial microvasculature by the mechanical motion of the beating heart and reduction in diastolic perfusion is responsible for myocardial ischemia in the absence of epicardial coronary artery stenosis, particularly in the subendocardium.…”

Section: Changes In Coronary Perfusion and Microcirculatory Function mentioning

confidence: 92%

“…3 Perimyocytic fibrosis 4 and reduction in the number of resistance vessels per unit weight 5 may contribute to the reduction in CVR in LVH secondary to hypertension and hypertrophic cardiomyopathy. However, recent work suggests that increased systolic impedance to coronary flow as a result of perivascular compression 6 and, most importantly, a reduction in diastolic perfusion 2 are the primary contributors to impairment of coronary microcirculatory function in AS, predominantly because of curtailment in maximal myocardial blood flow (MBF).…”

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confidence: 99%

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Functional Changes in Coronary Microcirculation After Valve Replacement in Patients With Aortic Stenosis

et al. 2003

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Background-Increased extravascular compression and reduced diastolic perfusion time (DPT), rather than vascular remodeling, influence coronary microcirculatory dysfunction in aortic stenosis (AS). However, alterations after aortic valve replacement (AVR) remain unclear. The aim of the present study was to quantify changes in transmural perfusion and coronary vasodilator reserve (CVR), a measure of microcirculatory function, after AVR and determine the relative contribution of left ventricular mass (LVM) regression, change in aortic valve area (AVA), and DPT. Methods and Results-Twenty-two patients with AS were studied before and 1 year after AVR using echocardiography to measure AVA, cardiovascular magnetic resonance to assess LVM, and positron emission tomography to quantify resting and hyperemic myocardial blood flow (MBF) and CVR. Regression of LVM occurred in all patients (from 129Ϯ30 to 94Ϯ24 g/m 2 ; PϽ0.0001), and there was a significant reduction in resting MBF and increase in CVR corrected for rate-pressure product after AVR, although these changes displayed marked heterogeneity. Regression of LVM was linearly related to change in resting total LV blood flow but not CVR. Increase in hyperemic MBF and CVR transmurally was directly related to the increase in AVA after AVR. A significant relationship existed between the change in hyperemic DPT (1.0Ϯ4.7 s/min [range, 6.8 to 9.6]) and change in transmural CVR (yϭ0.08xϩ0.18; rϭ0.44; Pϭ0.04). Conclusions-Changes

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Section: Changes In Coronary Perfusion and Microcirculatory Function mentioning

confidence: 92%

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confidence: 99%

Functional Changes in Coronary Microcirculation After Valve Replacement in Patients With Aortic Stenosis

et al. 2003

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“…5 These pathological changes slow myocardial relaxation, which in turn diminishes normal ventricular filling and reduces coronary blood flow. 6,7 This is compounded by the increase in work and myocardial mass, which results in elevated myocardial oxygen demand and a decrease in microvascular density, 8 leading to reduced coronary vascular reserve.…”

Section: Clinical Perspective On Pmentioning

confidence: 99%

Arterial Pulse Wave Dynamics After Percutaneous Aortic Valve Replacement

et al. 2011

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Background-Aortic stenosis causes angina despite unobstructed arteries. Measurement of conventional coronary hemodynamic parameters in patients undergoing valvular surgery has failed to explain these symptoms. With the advent of percutaneous aortic valve replacement (PAVR) and developments in coronary pulse wave analysis, it is now possible to instantaneously abolish the valvular stenosis and to measure the resulting changes in waves that direct coronary flow. Methods and Results-Intracoronary pressure and flow velocity were measured immediately before and after PAVR in 11 patients with unobstructed coronary arteries. Using coronary pulse wave analysis, we calculated the intracoronary diastolic suction wave (the principal accelerator of coronary blood flow). To test physiological reserve to increased myocardial demand, we measured at resting heart rate and during pacing at 90 and 120 bpm. Before PAVR, the basal myocardial suction wave intensity was 1.9Ϯ0.3ϫ10 Ϫ5 W ⅐ m Ϫ2 ⅐ s Ϫ2 , and this increased in magnitude with increasing severity of aortic stenosis (rϭ0. 59, Pϭ0.05). This wave decreased markedly with increasing heart rate (␤ coefficientϭϪ0. ; Pϭ0.014). Conclusions-In aortic stenosis, the coronary physiological reserve is impaired. Instead of increasing when heart rate rises, the coronary diastolic suction wave decreases. Immediately after PAVR, physiological reserve returns to a normal positive pattern. This may explain how aortic stenosis can induce anginal symptoms and their prompt relief after PAVR. Clinical Trial Registration-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01118442. Key Words: aortic stenosis Ⅲ aortic valve Ⅲ coronary arteries Ⅲ coronary flow Ⅲ heart valve prosthesis implantation Ⅲ microvessels Ⅲ wavelet analysis U ncorrected severe aortic stenosis has an extremely poor prognosis, carrying a 3-year mortality of Ͼ50%, 1 which rises to Ͼ80% in subjects with significant cardiac comorbidity. 2 As the severity of aortic stenosis increases, physiological and pathological adaptations occur in the left ventricle (LV). 3 These include increases in the inotropic state and the development of LV hypertrophy. 4 Editorial see p 1505 Clinical Perspective on p 1572Although LV hypertrophy can be viewed as a physiological adaptation to the increase in afterload, it encompasses a pathological hypertrophic response with increased extracellular matrix deposition and perivascular fibrosis. 5 These pathological changes slow myocardial relaxation, which in turn diminishes normal ventricular filling and reduces coronary blood flow. 6,7 This is compounded by the increase in work and myocardial mass, which results in elevated myocardial oxygen demand and a decrease in microvascular density, 8 leading to reduced coronary vascular reserve. 9 As the severity of the aortic stenosis increases, this process is exacerbated by ever-increasing afterload and decreasing coronary perfusion pressures, leading to the development of ischemia, which has been reported with the use of several different techniques. 10...

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“…The media=lumen ratio and perivascular collagen area were determined separately for arterioles with external diameters < 40 mm, 40 -80 mm, and > 80 mm. 23 An average of 35 vessels per sample were evaluated.…”

Section: Heart Weightmentioning

confidence: 99%

Myocardial infarction and coronary pathology in severely obese people examined at autopsy

Kortelainen

2002

Int J Obes

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OBJECTIVE: To find out the severity of coronary atherosclerosis and its relationship to body structure and adiposity in severely obese people with body mass index (BMI) ! 35.0 kg=m 2 and to examine the incidence and characteristic features of myocardial infarction and other fatal coronary events in this population. DESIGN: Autopsy reports were analyzed, including data on age, height, weight, abdominal subcutaneous fat thickness, heart weight, coronary atherosclerosis, histopathology and toxicology. Myocardial collagen and arteriolar structure were examined by computerized image analysis. SUBJECTS: Forensic autopsy cases (n ¼ 166) with a BMI ! 35.0 kg=m 2 examined in 1992 -1998 were collected from the files of the Department of Forensic Medicine, University of Oulu, Finland. RESULTS:In a large number of the severely obese individuals, the coronary arteries were either lesion-free or only fatty streaks were observed (38% of men, 44% of women) and coronary thrombosis was rare (3.8% of men and 1.6% of women). Cardiac causes of death predominated, cardiomyopathy being the commonest. Myocardial infarction was the immediate cause of death in 14.4% of men and 12.9% of the women, and it was associated with increased heart size in men. Coronary atherosclerosis without any infarction had been determined as the cause of death in 8.6% of the men and 8.1% of the women. Abdominal subcutaneous fat thickness had a significant negative association with the severity of coronary atherosclerosis in the women, and a decrease in the arteriolar media=lumen ratio with increasing BMI was observed in the men. CONCLUSIONS: A considerable number of severely obese people have only fatty streaks and no marked stenosis in their coronary arteries, even at an advanced age. The large amounts of subcutaneous adipose tissue in obese women may provide some protection against coronary lesion development, which could be an estrogen effect. Myocardial infarction in severely obese men is associated with cardiac hypertrophy. The significance of the BMI-related dilatation of the myocardial arterioles in men and its relationship to a remodelling of the epicardial arteries will require future investigations.

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Morphometric investigation of human myocardium in arterial hypertension and valvular aortic stenosis

Cited by 103 publications

References 0 publications

Functional Changes in Coronary Microcirculation After Valve Replacement in Patients With Aortic Stenosis

Functional Changes in Coronary Microcirculation After Valve Replacement in Patients With Aortic Stenosis

Arterial Pulse Wave Dynamics After Percutaneous Aortic Valve Replacement

Myocardial infarction and coronary pathology in severely obese people examined at autopsy

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