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Normal-flow low-gradient severe aortic stenosis (NF-LG-SAS), defined by an aortic valve area (AVA)

Although degenerative aortic valve stenosis (AS) is common with increasing age, limited data exist regarding the prevalence and prognostic impact of its various valve area-gradient patterns in patients ≥80 years. To test this, echocardiograms were obtained in 542 randomly selected subjects aged ≥80 years recruited in the Belgium Cohort Study of the Very Elderly study (BFC80+). Subjects were divided into 3 groups: no or mild AS, moderate AS, and severe AS. Patients with severe AS were further stratified into those with high mean gradients (HG-AS) and those with paradoxically low mean gradients (LG-AS). Prevalence of moderate-to-severe AS was 14.7% and that of severe AS was 5.9%. In patients with severe AS, most (72%) exhibited paradoxical LG-AS. All patients with severe HG-AS were asymptomatic at the time of inclusion, whereas 48% of those with severe paradoxical LG-AS had significant symptoms. During follow-up, there were 2 aortic valve replacements and 230 deaths, of which 100 (43%) were of cardiovascular origin. Five-year overall survival rate was significantly worse in severe HG-AS than in any of the other groups (22 ± 14% vs 62 ± 2% in no or mild AS, 48 ± 7% in moderate AS, and 43 ± 10% in severe paradoxical LG-AS, p0.01). Survival rate was similar among severe paradoxical LG-AS with and without low flow. In conclusion, in this large population-based sample of subjects ≥80 years, the prevalence of severe AS was 5.9%. Most of these subjects presented with the severe paradoxical LG-AS and a third of them were symptomatic. In this elderly community, severe HG-AS is a major determinant of prognosis, even in the absence of symptoms, whereas severe paradoxical LG-AS seems to behave similarly to moderate AS.

Low-gradient (LG), low-flow (LF), severe aortic stenosis (AS) with preserved ejection fraction (PEF) is considered by some authors as an advanced form of AS associated with very poor outcome. The aim of this Doppler echocardiographic study was to investigate changes over time in the hemodynamic severity of LG/LF AS with PEF. We retrospectively identified in 2 academic centers 59 patients who had 2 Doppler echocardiographic examinations without an intervening event. After a median follow-up of 2 (interquartile range [IQR] 1.3 to 3.5) years, progression was observed with increase in mean Doppler gradient (MDG; from 27 [23 to 32] to 37 [28 to 44] mm Hg; p

The early diastolic transmitral velocity/tissue Doppler imaging mitral annular early diastolic velocity (E/e') ratio is used to estimate left ventricular (LV) filling pressures at rest. However, there are only limited data that validate its use during exercise. Accordingly, the aim of this study was to test the ability of E/e' to estimate pulmonary capillary wedge pressure (PCWP) during symptom-limited exercise in patients with LV systolic dysfunction. Forty patients with severe LV dysfunction and heart failure symptoms (54 ± 12 years, 28 men) underwent simultaneous Doppler assessment of E/e' and right-sided cardiac catheterization at rest and during a symptom-limited exercise test, at steady state levels of 30%, 60%, and 90% of their maximal exercise capacity. During exercise, all 40 patients successfully completed stage 1, yielding 40 pairs of data for comparison. Eighteen patients also successfully completed stage 2, and 5 patients also made it through stage 3, yielding 23 additional data pairs. In total, there were thus 63 pairs of data available during exercise. With exercise, heart rate increased from 77 ± 14 to 112 ± 21 beats/min. Septal E/e' at rest correlated well with PCWP at rest (r = 0.75, p0.01). PCWP at rest also correlated with resting mitral deceleration time (r = 0.32, p0.01) and with the transmitral E/A ratio (r = 0.74, p0.01). During exercise, the correlation between septal E/e' and PCWP was weaker (r = 0.57, p0.01) and was shifted to the right. This rightward shift was observed in patients with both separated or merged E and A velocities. In conclusion, in patients with severe LV dysfunction, although E/e' allows accurate estimation of PCWP at rest, it appears less reliable for estimating LV filing pressure during exercise.

Advances over the past 10 years have enabled the widespread use of myocardial contrast echocardiography (MCE) to assess myocardial perfusion. This assessment is critical in evaluating the severity of coronary artery disease and the efficacy of pharmacologic, mechanical, or surgical interventions. MCE measures myocardial blood flow (MBF) by investigating flow velocity and myocardial blood volume. Although there are potential limitations to the use of MCE for determining MBF, its use is feasible in the experimental laboratory and in the clinical environment.

Although exercise intolerance is a cardinal symptom of patients with dilated cardiomyopathy (DC) and heart failure, the factors that limit exercise capacity in these patients remain a matter of debate. To assess the contribution of left ventricular (LV) diastolic filling to the variable exercise capacity of patients with DC, we studied 47 patients (60 +/- 12 years) with DC in stable mild-to-moderate heart failure with a mean LV ejection fraction of 28%. Exercise capacity was measured as total body peak oxygen consumption (VO2) during symptom-limited bicycle (10 W/min) and treadmill (modified Bruce protocol) exercise. LV systolic function and diastolic filling were assessed at rest before each exercise by M-mode, Doppler echocardiography, and radionuclide ventriculography. As expected, treadmill exercise always yielded higher peak VO2 than bicycle exercise (21 +/- 6 vs 18 +/- 5 ml/kg/min, range 12 to 35 and 7 to 30 ml/kg/min, respectively, p

Dipyridamole single-photon emission computed tomography (SPECT) has a high negative predictive value for perioperative cardiac events, but events are infrequent in patients with a positive test. In contrast, dipyridamole echocardiography is more selective for detection of multivessel disease and thus may have a greater specificity for cardiac events. We therefore compared the ability of dipyridamole SPECT and echocardiography to predict perioperative and long-term cardiac events in 133 patients referred for vascular surgery, The group was also evaluated based on clinical features and election fraction. Four patients had surgery cancelled because of high risk and were excluded from further analysis. Among the 129 remaining patients, 21 had coronary revascularization (n = 12) or an early cardiac end point (n = 9). The sensitivity of SPECT for the prediction of early events (90%) was not significantly different from that of echocardiography (66%, p = NS). The specificity of SPECT (68%) was less than that of echocardiography (88%, p < 0.001%), as was the accuracy (72% vs 84%, p = 0.02). These findings were replicated after exclusion of patients with treatment end points. During long-term follow-up, 12 patients experienced greater than or equal to 1 event: 6 died from cardiac causes, 4 underwent revascularization, and 3 had myocardial infarction. Thus, the specificity of SPECT and echocardiography for late events were 58% and 80%, respectively (p < 0.001). The 3-year survival of patients without ischemia during echocardiography or at SPECT was not different (93% vs 94%, p = NS). (C) 1998 by Excerpta Medica, Inc.

Pulmonary arterial wedge pressure (PAWP) is an important marker of cardiac function. Regrettably, it requires catheterization, which can occasionally result in serious complications. A noninvasive method of estimating PAWP would thus be helpful. Recent studies have indicated that the Doppler transmitral flow velocity pattern was strongly dependent on preload and could provide an estimate of PAWP. This study was therefore designed to evaluate the relation between doppler transmitral flow velocity indexes and measured PAWP in 91 patients (learning group: 73 men, mean age 57 +/- 13 years) with ischemic heart disease (n = 41), dilated (n = 29) or hypertrophic cardiomyopathy (n = 4), or aortic stenosis (n = 17). Multiple regression analysis was used to derive an equation for estimation of PAWP, which was subsequently tested in a separate group of 33 patients (testing group: 28 men, mean age 58 +/- 12 years) with similar cardiac conditions. PAWP ranged from 4 to 48 mm Hg in the learning group and from 7 to 40 mm Hg in the testing group. In the learning group, PAWP correlated with the E/A ratio (r = 0.95), atrial filling fraction (r = -0.80), peak E velocity (r = 0.79), isovolumic relaxation period (r = -0.75), and deceleration time (r = -0.61). In the learning group, PAWP was best predicted as PAWP = 18.4 + [17.1.In(E/A ratio)]. This equation allowed prediction of PAWP within 3 mm Hg of the measured value in 24 of 33 patients (73%) in the testing group. In 8 additional patients, the equation also accurately predicted the changes in PAWP induced by volume loading or intravenous nitrates (r = 0.98).(ABSTRACT TRUNCATED AT 250 WORDS)

Studies estimating the added value of natriuretic peptide levels and electrocardiographic findings beyond all relevant clinical information to identify cardiac dysfunction remain scarce. The aim of this study was to assess the presence of clinically relevant cardiac dysfunction in an unselected population of subjects aged ≥80 years. A cross-sectional analysis using an "intention-to-diagnose" strategy was performed within the BELFRAIL study (n = 567). Baseline B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide levels were determined and echocardiography was performed at subjects' homes. Logistic regression analysis and classification and regression tree analysis were used as complementary analytic tools. Cardiac dysfunction was present in 17% of subjects without and 31% of subjects with chronic atrial fibrillation (AF) or pacemaker. In subjects without chronic AF or pacemaker, the clinical model showed a C-statistic of 0.79 (95% confidence interval 0.74 to 0.85). The combination of natriuretic peptides with normal results on electrocardiography increased, only marginally, the C-statistic. In subjects with chronic AF or pacemaker, the clinical model showed a very high C-statistic of 0.90 (95% confidence interval 0.82 to 0.98). Classification and regression tree analysis showed that an additional 58 subjects (13%) were correctly classified using natriuretic peptides and electrocardiographic findings among those without chronic AF or pacemaker. Of participants with chronic AF or pacemaker, >90% were correctly classified. In conclusion, in a large population-based sample of patients aged ≥80 years, the clinical model possessed high accuracy to identify cardiac dysfunction in daily practice. Among subjects without chronic AF or pacemaker, a larger number were correctly classified by integrating natriuretic peptides and electrocardiographic findings in the strategy.

Proximal isovelocity surface area (PISA) has been proposed as a quantitative method to assess the severity of aortic regurgitation (AR). Yet the accuracy of this method in patients with eccentric AR jets is unknown. The aims of this study were to compare the accuracy of the PISA method for the quantification of AR severity in patients with central versus eccentric AR jets and to verify whether imaging from the left parasternal instead of the apical window improves the accuracy of the PISA method in patients with eccentric jets. Fifty patients with AR (21 with central jets and 29 with eccentric jets) underwent PISA and phase-contrast cardiac magnetic resonance (CMR) measurements of AR volume. In patients with eccentric AR jets, PISA measurements obtained from the left parasternal and apical windows were compared. In patients with central AR jets, CMR- and PISA-derived AR volumes were similar (28 +/- 19 vs 30 +/- 20 ml, p = 0.34), were strongly correlated (r = 0.92, p

Contractile function in patients with ischemic left ventricular (LV) dysfunction may improve after myocardial revascularization. Currently, the incidence of contractile function recovery after revascularization in these patients is unclear. The aim of this study was to assess the incidence of function improvement after myocardial revascularization in patients with ischemic LV dysfunction. A total of 258 consecutive patients (aged 59 +/- 12 years) with severely depressed LV ejection fractions (EFs) due to chronic coronary artery disease and heart failure symptoms were studied. All patients underwent radionuclide ventriculography and 2-dimensional echocardiography at rest before and 3 to 6 months after revascularization. At baseline, 1,330 segments (32%) were normal and 2,775 segments (68%) were dysfunctional. Improvement after revascularization occurred in 736 of the 2,775 dysfunctional segments (27%). Overall, LVEF improved from 29 +/- 7 to 32 +/- 9 (p0.0001). A clinically significant improvement of LVEF (/=5% postrevascularization) was present in 101 patients (39%). Improvement of LVEF after revascularization was frequently observed in patients with a more severely impaired baseline LVEF. At least 3 segments with improvement of function were needed for an improvement of LVEF of/=5%.

P the beneficial effects of revascularization result from restoring blood supply to dysfunctional but viable myocardial regions with subsequent improvement in regional and global left ventricular (LV) function. During the past decade, delineation of viable from nonviable myocardium has been the focus of considerable attention and has fostered the development of several new modalities aimed at predicting the return of LV function after revascularization. Among these modalities, low-dose dobutamine echocardiography has recently emerged as a safe, noninvasive, and accurate means of identification of viable myocardium. Although existing data suggest that low-dose dobutamine echocardiography is useful in predicting outcome in patients with moderately depressed LV function, there are no data regarding the prognostic impact of this modality in patients with severe LV dysfunction (i.e., an ejection fraction 25%). Accordingly, the aim of the present study was to evaluate the prognostic value of low-dose dobutamine echocardiography in patients with severely depressed LV function undergoing coronary bypass grafting (CABG).

This study evaluated recently suggested invasive and noninvasive parameters of myocardial reperfusion after acute myocardial infarction (AMI), assessing their predictive value for left ventricular function 4 weeks after AMI and reperfusion defined by myocardial contrast echocardiography (MCE). In 38 patients, angiographic myocardial blush grade, corrected Thrombolysis In Myocardial Infarction frame count, ST-segment elevation index, and coronary flow reserve (n = 25) were determined immediately after primary percutaneous transluminal coronary angioplasty [PTCA) for first AMI, and intravenous MCE was determined before, and at I and 24 hours after PTCA to evaluate myocardial reperfusion. Results were related to global wall motion index (GWMI) at 4 weeks. MCE I hour after PTCA showed good correlation with GWMI at 4 weeks (r = 0.684, p

We compared the use of transthoracic echocardiography with second harmonic imaging after a peripheral intravenous injection of an agitated saline solution with transesophageal echocardiography (TEE) in the detection of right to left shunts at the cardiac and pulmonary level. Second harmonic mode transthoracic echocardiography and TEE are equally sensitive in detecting right to left shunts in patients undergoing a daily routine TEE.

Chronic left ventricular (LV) ischemic dysfunction, a condition often referred to as myocardial hibernation, is associated in humans with ultrastructural alterations of the myocytes, including the loss of myofilaments and the accumulation of glycogen. Given the severity of these structural changes, contractile function is unlikely to resume immediately upon revascularization. Therefore, the aim of the present study was to assess the time course of functional improvement after successful revascularization as well as its potential structural correlates. We studied 32 patients with coronary disease and chronic LV ischemic dysfunction who underwent bypass surgery. Dynamic positron emission tomography with N-13 ammonia and F-18 deoxyglucose to assess myocardial perfusion and glucose metabolism was performed in 29 patients. In all patients, a transmural biopsy was harvested from the center of the dysfunctional area, to quantify the increase in extracellular matrix and the presence of structurally altered cardiomyocytes. LV function was serially measured by digitized 2-dimensional echocardiography before and at 10 days, 2 months, and 6 months after revascularization. The time course of recovery of regional function was estimated from the monoexponential decrease in dysfunctional wall motion score. At follow-up, 19 patients had improved LV function, whereas 13 patients showed persistent dysfunction. Before revascularization, reversibly dysfunctional segments had higher myocardial blood flow (82 +/- 29 vs 53 +/- 21 ml. (min. 100 g)(-1), p = 0.044), higher glucose uptake (40 +/- 16 vs 21 +/- 9 micromol. (min. 100 g)(-1), p = 0.001), and less increase in extracellular matrix (25 +/- 15% vs 46 +/- 17%, p = 0.0008) than segments with persistent dysfunction. The extent to which function recovered was positively correlated with myocardial blood flow and negatively correlated with the increase in the extracellular matrix. In patients with reversible dysfunction, the return of segmental function was progressive and followed a monoexponential time course with a median time constant of 23 days (range 6 to 78). The rate of recovery correlated best with the proportion of altered cardiomyocytes in the biopsy. The present study thus indicates that the recovery of regional and global LV function after successful revascularization is progressive and follows a monoexponential time course that is influenced by the extent of the structural changes affecting cardiomyocytes.

Dilated cardiomyopathy (DCM) is a major cause of mortality among patients with heart failure. The aim of the present study was to investigate the independent contribution of Doppler-derived left ventricular (LV) filling to the prediction of survival in patients with DCM, of either ischemic or nonischemic origin, and to derive a simple risk stratification score based on easily available clinical and echocardiographic parameters. We followed 197 consecutive patients (159 men, mean age 60+/-13 years) with an echocardiographic diagnosis of DCM (LV end-diastolic dimension >60 mm, fractional shortening

Previous studies have shown that viable but stunned myocardium displays contractile reserve and exhibits cardiac cycle-dependent variations of integrated backscatter, whereas infarcted myocardium does not. The present study was designed to evaluate whether integrated backscatter imaging could be useful in identifying segments with recruitable inotropic reserve in patients with chronic left ventricular (LV) ischemic dysfunction. We studied 15 patients (mean age 59 +/- 10 years) with chronic coronary artery disease, anterior or inferior wall dysfunction, and depressed LV ejection fraction (35 +/- 12%), and 6 noncardiac control subjects (mean age 49 +/- 18 years). Cardiac cycle-dependent variations of integrated backscatter were measured in anterior and inferior segments during transesophageal echocardiography and compared with the contractile response (% wall thickening) of these segments to low doses of dobutamine (5 to 10 microg/kg/min). The average magnitude of cardiac cycle-dependent variations of integrated backscatter was greater among normally contracting segments of both patients and controls (5.67 +/- 0.88 and 5.64 +/- 2.26 dB, respectively, p = NS) than among dysfunctional segments (2.77 +/- 3.05 dB, p

Low-dose dobutamine echocardiography has a high sensitivity for predicting functional recovery after revascularization. In segments with mild wall motion abnormalities, the specificity of the technique is rather low, suggesting overestimation of functional recovery in these segments.

This study compared the efficacy of dobutamine stress testing using 2-dimensional echocardiography and perfusion tomography for the noninvasive identification of coronary artery disease (CAD) in patients with left bundle branch block (LBBB). Twenty-four patients with permanent, complete LBBB (11 with previous myocardial infarction) were studied prospectively with dobutamine echocardiography and perfusion tomography. The presence of > 50% luminal diameter coronary stenosis was compared with the presence of dobutamine-induced fixed or reversible perfusion defects, and with resting or dobutamine-induced abnormalities of wall thickening. For each test, the left anterior coronary artery territory was compared with the circumflex and/or right coronary artery. Significant CAD was found in the left anterior descending coronary artery in 12 patients; all (100%) were identified by perfusion imaging, and 10 (83%, p = NS) by 2-dimensional stress echocardiography. In the 12 patients without left anterior descending CAD, scintigraphy was also positive in all (specificity: 0%), and echocardiography in only 1 (specificity: 92%, p < 0.01). The diagnostic accuracy was 50% and 87% (p < 0.05), respectively. This low specificity of perfusion tomography was improved by requiring an associated apical defect to indicate left anterior descending CAD and was corrected by restricting the diagnosis of coronary disease to those patients with partially reversible defects. In the circumflex and/or right coronary artery territory, sensitivity and specificity were similar using both techniques. We conclude that dobutamine-stress echocardiography is a specific and accurate test for the noninvasive identification of CAD, even in the left anterior descending artery territory of patients with LBBB.

Despite this limitation, ABD with backscatter imaging is a promising new technique that permits clinically meaningful quantification of LV volumes and ejection fraction. It therefore constitutes an important step toward truly quantitative echocardiography. It is hoped that future developments will reduce the need for operator manipulation and improve the reliability of the technique.

The influence of transmitral filling dynamics on the evaluation of aortic regurgitation (AR) by continuous-wave Doppler pressure half-time was assessed in 30 consecutive patients in sinus rhythm with chronic moderate to severe AR. Pulsed-wave Doppler-derived regurgitant fraction (obtained from aortic and pulmonary stroke volumes) and color flow mapping relative regurgitant area (obtained from the parasternal short-axis view) were chosen as reference standards for the severity of AR. An excellent correlation was found between these 2 parameters (r = 0.98), while correlations were poor between pressure half-time and either regurgitant fraction (r = -0.74) or relative regurgitant jet area (r = -0.69). The ratio of early (E) to late (A) transmitral peak velocities was used to divide the study population into 2 groups: group A (n = 16) with E/A less than 1 and group B (n = 14) with E/A greater than 1. In patients with a similar degree of AR (estimated from Doppler regurgitant fraction or relative regurgitant jet area), the pressure half-time was found to be significantly shorter. Thus, the severity of AR in group A patients was overestimated (p less than 0.01). Compared to group B, group A patients were significantly shorter. Thus, the severity of AR in group A patients was overestimated (p less than 0.01). Compared to group B, group A patients were significantly older (p less than 0.02) and had a larger left ventricular mass (p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)