Significance of echocardiographic left atrial enlargement in aortic stenosis

This study investigated the significance of echocardiographic left atrial enlargement as measured by the left atrial dimension corrected for body surface area in 24 patients with pure aortic stenosis established by cardiac catheterization. Echocardiographic evidence of left atrial enlargement occurred in 11 of 15 patients (73%) with an aortic valve area below 0.8 cm2 and in none of nine patients (0%) with an aortic valve area above 0.8 cm2, p less than 0.0025. All 11 patients (100%) with an enlarged left atrial dimension had an increased diastolic left ventricular dimension, whereas 1 of 13 patients (8%) with a normal left atrial dimension had an increased diastolic left ventricular dimension, p less than 0.00001. The 11 patients (100%) with an enlarged left atrial dimension had increased posterior left ventricular wall thickness, whereas 2 of 13 patients (13%) with a normal left atrial dimension had increased posterior left ventricular wall thickness (p less than 0.0005). These data lead one to conclude that in patients with pure aortic stenosis, echocardiographic evidence of left atrial enlargement as measured by an increased left atrial dimension corrected for body surface area should lead one to suspect severe aortic stenosis.     

Catheterization-Doppler discrepancies in nonsimultaneous evaluations of aortic stenosis

Prior validation studies have established that simultaneously measured catheter (cath) and Doppler mean pressure gradients (MPG) correlate closely in evaluation of aortic stenosis (AS). In clinical practice, however, cath and Doppler are rarely performed simultaneously; which may lead to discrepant results. Accordingly, our aim was to ascertain agreement between these methods and investigate factors associated with discrepant results. We reviewed findings in 100 consecutive evaluations for AS performed in 97 patients (mean age 72 +/- 10 yr) in which cath and Doppler were performed within 6 weeks. We recorded MPG, aortic valve area (AVA), cardiac output, and ejection fraction (EF) by both methods. Aortic root diameter, left ventricular end-diastolic dimension (LVIDd) and posterior wall thickness (PWT) were measured by echocardiography and gender, heart rate, and heart rhythm were also recorded. An MPG discrepancy was defined as an intrapatient difference > 10 mmHg. Mean pressure gradients by cath and Doppler were 36 +/- 22 mmHg and 37 +/- 20 mmHg, respectively (P = 0.73). Linear regression showed good correlation (r = 0.82) between the techniques. An MPG discrepancy was found in 36 (36%) of 100 evaluations; in 19 (53%) of 36 evaluations MPG by Doppler was higher than cath, and in 17 (47%) of 36, it was lower. In 33 evaluations, EF differed by >10% between techniques. Linear regression analyses revealed that EF difference between studies was a significant predictor of MPG discrepancy (P = 0.004). Women had significantly higher MPG than men by both cath and Doppler (43 +/- 25 mmHg versus 29 +/- 15 mmHg [P = 0.001]; 42 +/- 23 mmHg versus 32 +/- 15 mmHg [P = 0.014], respectively). Women exhibited discrepant results in 23 (47%) of 49 evaluations versus 13 (25%) of 51 evaluations in men (P = 0.037). After adjustment for women's higher MPG, there was no statistically significant difference in MPG discrepancy between genders (P = 0.22). No significant interactions between MPG and aortic root diameter, relative wall thickness (RWT), heart rate, heart rhythm, cardiac output, and time interval between studies were found. In clinical practice, significant discrepancies in MPG were common when cath and Doppler are performed nonsimultaneously. No systematic bias was observed and Doppler results were as likely yield lower as higher MPGs than cath. EF difference was a significant predictor of discrepant MPG. Aortic root diameter, relative wall thickness, heart rate, heart rhythm, cardiac output, presence or severity of coronary artery disease, and time interval between studies were not predictors of discrepant results.     

The effect of aortic valve replacement on N-terminal natriuretic propeptides in patients with aortic stenosis

BACKGROUND: Increased plasma concentrations of natriuretic peptides have been demonstrated to be associated with increased intracardiac pressure and left ventricular (LV) hypertrophy. After aortic valve replacement (AVR) in aortic stenosis patients, there is a relief of the left outflow obstruction with a substantial hemodynamic improvement. This is followed by a gradual regression of the LV hypertrophy. HYPOTHESIS: After AVR, reduction in LV filling pressure is expected to occur rapidly, while regression of LV hypertrophy will take place over a longer time period. On this basis we hypothesized that the plasma levels of N-terminal proatrial natriuretic peptide (NT-proANP) would be reduced early in the postoperative period, while N-terminal probrain natriuretic peptide (NT-proBNP), through its closer reflection of LV hypertrophy, would be sustained for a longer period. METHODS: Two groups of patients with aortic stenosis undergoing AVR were followed for 4 and 12 months, respectively. Plasma concentrations of NT-proANP and NT-proBNP were measured before and after AVR and related to preoperative findings and changes in the aortic valve area index. RESULTS: Before AVR, the patients had significantly increased plasma levels of NT-proANP and NT-proBNP. After AVR, NT- proANP was decreased at 4 and 12 months but remained elevated compared with controls. N-terminal-proBNP tended to decrease, but did not change significantly. When the patients were followed for 12 months, only those with elevated preoperative pulmonary capillary wedge pressure had decreased peptide levels (NT-proANP: p = 0.017, NT-proBNP: p = 0.058). There was no regression of LV hypertrophy. The patients with the largest postoperative valve area index [1.27 (1.10-1.55) cm2/m2] had the largest reduction of NT-proBNP (47%). Those with the smallest valve area index [0.67 (0.54-0.73) cm2/m2] had no decrease in NT-proBNP. CONCLUSIONS: Our study suggests that a reduction in left atrial pressure is the main factor causing the change of NT-proANP level after AVR. A small prosthetic valve orifice area with a high aortic valve gradient might prevent regression of LV hypertrophy, thus representing a stimulus for increased cardiac secretion of NT-proBNP.     

End-systolic pressure-volume and end-systolic stress-volume relationships in patients with aortic stenosis and with normal valvular function

Summary In order to study the effect of left ventricular hypertrophy on the endsystolic pressure-volume relationship, three left ventricular angiograms were performed in ten patients with normal valvular function but with varying left ventricular function (group 1) after 0.15 mg/kg propranolol, and 1 mg atropine: at rest, after isosorbide-dinitrate at a decreased afterload and after methoxamine at an enhanced afterload. In eight patients with aortic stensis (group 2) two left ventricular angiograms were performed: at rest and after isosorbide-dinitrate. Heart rate was kept constant by atrial pacing.Left ventricular mass in group 1 was 89 g/m² and in group 2 180 g/m². In group 1 the slope k of the end-systolic pressure-volume relation was related to the ejection fraction (EF) at rest: k=0.024·e^{0.072 EF}; r=0.93. In group 2 this relation was shifted to the left (P<0.001): k=0.135·e^{0.057 EF}; r=0.81. The relations, however, between the slope k of the end-systolic stress-volume relation and the ejection fraction were close together in group 1 and in group 2 and crossed at an ejection fraction of 67%.It is concluded: 1. In patients with aortic stenosis the end-systolic pressure-volume relation is steeper than in patients without valvular dysfunction at a given ejection fraction, so the relation between the slope k and the ejection fraction is shifted to the left. 2. The end-systolic stress-volume relationship is not altered in patients with aortic stenosis and seems to be advantageous for the evaluation of left ventricles with substantial hypertrophy due to pressure load.Presented in part at the 53rd Scientific Sessions of the American Heart Association in Miami Beach, Florida, Nov. 1980These investigations were supported by a grant from the Bundesministerium für Forschung und Technologie, Grant No. DISMED 18.     

The myocardial performance index in patients with aortic stenosis

OBJECTIVES: This study was designed to determine the effect of chronic afterload on a Doppler-derived myocardial performance index (MPI) combining both systolic and diastolic left ventricular dysfunction. METHODS: The study included 36 patients with a diagnosis of aortic stenosis and 36 normal subjects. Doppler-derived myocardial performance index (MPI), defined as the sum of the isovolumic contraction time and isovolumic relaxation time divided by ejection time, was measured from the mitral valve inflow and left ventricular outflow velocity patterns and was then related to the aortic valve area, valve gradient, and other echocardiographic variables. RESULTS: The values of the Doppler-derived MPI in the patients with aortic stenosis were significantly higher than those in the controls (0.54 +/- 0.20 vs 0.38 +/- 0.04, respectively; P < 0.001). Transmitral deceleration time and the E/A ratio ( r = 0.47 and r = 0.35, respectively; P < 0.05) were significant univariate correlates, and mitral deceleration time was the only significant correlate of MPI. However the index did not correlate with aortic valve area, peak and mean valve gradients, left ventricular mass, or age. CONCLUSIONS: Doppler-derived MPI reflects severity of global left ventricular dysfunction in patients with aortic stenosis and may be of clinical value in this patient population.     

基于超声心动图的钙化性主动脉瓣疾病患病情况的回顾性研究

目的分析钙化性主动脉瓣疾病(CAVD)的患病情况。方法收集并回顾性分析行超声心动图检查年龄≥45岁患者的临床资料17 826例,男性9725例,女性8101例,其中45⁶4岁11 274例,6564岁11 274例,65⁷4岁4250例,7574岁4250例,75⁸4岁2052例,≥85岁250例。结果CAVD总患病率为12.8%,男性CAVD患病率明显高于女性(13.6%vs11.9%),CAVD发生年龄明显低于女性[(70±10)岁vs(71±10)岁,P=0.001]。CAVD患病率随着年龄增长明显增高,4584岁2052例,≥85岁250例。结果CAVD总患病率为12.8%,男性CAVD患病率明显高于女性(13.6%vs11.9%),CAVD发生年龄明显低于女性[(70±10)岁vs(71±10)岁,P=0.001]。CAVD患病率随着年龄增长明显增高,45⁶4岁,6564岁,65⁷4岁,7574岁,75⁸4岁,≥85岁4个年龄段患病率分别为5.3%、20.5%、32.9%和54.4%。CAVD患者最常受累及的瓣叶为无冠瓣,其次是右冠瓣+无冠瓣、右冠瓣和左冠瓣。CAVD患者常见的功能异常为主动脉瓣反流,且主动脉瓣反流较狭窄明显多见(77.1%vs 15.0%,P<0.01)。CAVD患者左心房扩大发生率明显高于左心室扩大(56.3%vs 22.2%),室间隔肥厚发生率明显高于左心室后壁(51.7%vs 24.2%,P<0.01)。结论 CAVD患病率随年龄增长显著增高。     

术前左心房最小容积对主动脉瓣狭窄术后症状的预测价值

目的 探讨术前左心房最小容积（LAVmin）对重度主动脉瓣狭窄（AS）患者外科主动脉瓣置换术(SAVR)后症状的预测能力。方法 本研究为前瞻性研究。入选2011年3月至2017年11月在福建医科大学附属漳州市医院行SAVR的AS患者84例,术前行超声心动图检查测量包括LAVmin指数（LAVmin经体表面积校正得到LAVImin）在内的相关参数,术后进行1年的随访,记录术后1个月至12个月之间出现的心力衰竭症状。根据术后心力衰竭症状有无,将患者分为两组：术后症状组（20例）,术后无症状组（64例）。用受试者工作特征（ROC）曲线评估超声心动图相关参数对术后症状的预测能力,采用多元Logistic回归分析评估术后症状的相关因素。结果 两组患者之间,术前左心室容积、左心室射血分数及左室舒张功能障碍程度均无明显差异。而术前LAVImin,在术后症状组和术后无症状组之间则存在显著差异[(45.1±11.6)ml/m2 比 (27.1±9.2)ml/m2,P＜0.01]。ROC曲线分析显示,当LAVImin ≥ 30.3 ml/m2时,ROC曲线下面积最大（0.84,敏感性94.1％,特异性69.6％）。在多元Logistic回归分析中,术前LAVImin是AS术后症状的独立预测因子（OR=2.17,95％CI 1.04～2.96,P=0.02)。结论 经超声心动图测得的术前LAVImin可作为AS患者SAVR术后症状的预测指标,术前LAVImin≥30.3 ml/m2有助于重度AS行SAVR手术时机的选择。     

The spectrum of left ventricular filling in severe aortic stenosis

To assess left ventricular diastolic filling in valvular aortic stenosis, pulsed Doppler echocardiography was used prospectively in 35 patients with severe aortic stenosis (valve area < 1 cm²) and in 38 age-matched normal subjects. Twenty-seven patients had a normal left ventricular systolic function at rest (ejection fraction > 0.50) and a normal or only slightly increased mean pulmonary capillary wedge pressure (mean 11±4 mm Hg). Eight patients had a poor left ventricular systolic function (ejection fraction: 0.28±0.10) and an elevated mean pulmonary capillary wedge pressure (mean: 36±9 mm Hg).The Doppler derived filling parameters were correlated with hemodynamic data, left ventricular wall thickness derived from M-mode echocardiograms, heart rate and atrio-ventricular (A-V) conduction delay using stepwise multiple correlation. The data of this study suggest that left ventricular filling is significantly impaired in patients with severe aortic stenosis and left ventricular hypertrophy with an increase in late diastolic (A-wave) velocity, an increase in the A/E ratio, a decrease in the first one-half filling fraction and a prolongation of early diastolic deceleration time. These changes in filling hemodynamics are associated with alterations in mean pulmonary capillary wedge pressure, left ventricular wall thickness, heart rate and A-V conduction delay. When heart failure develops as a result of impaired left ventricular systolic function, an increase in left atrial filling pressure is associated with a shift of left ventricular filling towards early diastole with a normalisation of the transmitral flow velocity curve. In extreme cases, a progression towards a restrictive filling pattern is found with a marked shortening of the left ventricular early diastolic deceleration time.In the presence of high filling pressures, increased left atrial driving pressure (derived from the mean pulmonary capillary wedge pressure) is associated with changes in the left ventricular filling pattern irrespective of the presence and the degree of myocardial hypertrophy.     

Failure of left ventricular hypertrophy to regress after surgery for aortic valve stenosis

BACKGROUND: Regression of left ventricular (LV) hypertrophy usually follows surgery for aortic stenosis (AS); however, a significant number of ventricles remain hypertrophied. The extent of this phenomenon, the reasons for failure to regress, and its significance are unclear. METHODS: We investigated 43 patients before and after aortic valve surgery and divided them into two groups: 30 patients with regression of LV hypertrophy (Group A) and 13 patients without regression (Group B). Preoperative echocardiographic measurements, clinical status, and operative factors were compared between the two groups. The patients were followed up for 42 +/- 22 months for the occurrence of hospitalization for congestive heart failure (CHF) or death. RESULTS: Preoperatively, the two groups were similar except for an excess of patients in New York Heart Association (NYHA) functional Class IV and a greater incidence of old myocardial infarcts in Group B. Postoperatively, Group B patients had larger LVs with decreased systolic function. This was associated with a poor prognosis (23% mortality and 38% CHF vs 0% and 4% for Group A patients, P = 0.0002). Cox regression analysis showed previous myocardial infarction (P < 0.001) and percent mass reduction (P = 0.019) to be independent predictors of CHF or death. CONCLUSIONS: Successful regression of LV mass is difficult to predict before surgery; however, its absence is related strongly to a poor long-term prognosis.     

Sequential study of left ventricular function in aortic valvular stenosis

To assess the progression of aortic valvular gradients (AVG) and their relation to left ventricular function, 21 patients with aortic valvular stenosis were studied sequentially by cardiac catheterization and left ventriculography. All AVG were obtained from the left ventricle to ascending aortic pullback tracings. The ejection fraction and mean velocity of circumferential fiber shortening were obtained from left ventriculograms. A new onset of syncopal episode was helpful to predict the progression of AVG in five patients, but in others the progression of aortic stenosis was generally not predictable. The left ventricular contractility of these patients was usually normal, but seven patients exhibited the progressive impairment that was not proportional to the change of AVG and was clinically unrecognized. Also, the left ventricular function may deteriorate in the absence of progression of the aortic valvular gradient. Thus, serial hemodynamic studies could be indicated in patients with mild to moderate aortic stenosis even in the absence of new symptoms and signs.     

Left ventricular response to exercise in aortic stenosis: an exercise echocardiographic study

BACKGROUND: While normal at rest, left ventricular (LV) systolic function may become abnormal during exercise in patients with aortic stenosis. Once contraindicated in patients with aortic stenosis, exercise testing is now recommended in asymptomatic patients with aortic stenosis to elicit symptoms and thereby ascertain the need for aortic valve replacement. However, the clinical significance of an abnormal LV response to exercise in asymptomatic patients with aortic stenosis remains unknown. OBJECTIVE: The aim of this study was to evaluate the clinical implications of an abnormal LV response during exercise in the setting of aortic stenosis. METHODS: We monitored the LV response to exercise by 2D-Doppler echocardiography during a symptom limited semirecumbent bicycle exercise in 50 patients with tight aortic stenosis (aortic valve area < or = 1.0 cm(2)) and a normal LV systolic function (LV ejection fraction, EF > or = 50%) and followed them for an average of 11 months. RESULTS: Twenty patients had an abnormal LV response to exercise with a mean decrease in LV EF from 64 +/- 10 to 53 +/- 12% while 30 patients had a normal LV response to exercise with a mean increase in LV EF from 62 +/- 7 to 70 +/- 8%. Patients with an abnormal LV response during exercise were more likely to develop symptoms during exercise than patients with a normal LV response: 80% versus 27% (P< 0.0001). The survival free of cardiac events was significantly lower in patients with abnormal LV response to exercise than in patients with a normal response (P = 0.03). CONCLUSION: Exercise echocardiography provides objective data that facilitate interpretation of exercise elicited symptoms in asymptomatic patients with severe aortic stenosis. In addition, an abnormal LV response to exercise may predict a poor outcome.