Marilyn F. Riley

Importance of imaging method over imaging modality in noninvasive determination of left ventricular volumes and ejection fraction: assessment by two- and three-dimensional echocardiography and magnetic resonance imaging.

OBJECTIVES This study sought to determine the concordance between biplane and volumetric echocardiography and magnetic resonance imaging (MRI) strategies and their impact on the classification of patients according to left ventricular (LV) ejection fraction (EF) (LVEF). BACKGROUND Transthoracic echocardiography and MRI are noninvasive imaging modalities well suited for serial evaluation of LV volume and LVEF. Despite the accuracy and reproducibility of volumetric methods, quantitative biplane methods are commonly used, as they minimize both scanning and analysis times. METHODS Thirty-five adult subjects, including 25 patients with dilated cardiomyopathies, were evaluated by biplane and volumetric (cardiac short-axis stack) cine MRI and by biplane and volumetric (three-dimensional) transthoracic echocardiography. Left ventricular volume, LVEF and LV function categories (LVEF > or =55%, >35% to <55% and < or =35%) were then determined. RESULTS Biplane echocardiography underestimated LV volume with respect to the other three strategies (p < 0.01). There were no significant differences (p > 0.05) between any of the strategies for quantitative LVEF. Volumetric MRI and volumetric echocardiography differed by a single functional category for 2 patients (8%). Six to 11 patients (24% to 44%) differed when comparing biplane and volumetric methods. Ten patients (40%) changed their functional status when biplane MRI and biplane echocardiography were compared; this comparison also revealed the greatest mean absolute difference in estimates of EF for those subjects whose EF functional category had changed. CONCLUSIONS Volumetric MRI and volumetric echocardiographic measures of LV volume and LVEF agree well and give similar results when used to stratify patients with dilated cardiomyopathy according to systolic function. Agreement is poor between biplane and volumetric methods and worse between biplane methods, which assigned 40% of patients to different categories according to LVEF. The choice of imaging method (volumetric or biplane) has a greater impact on the results than does the choice of imaging modality (echocardiography or MRI) when measuring LV volume and systolic function.

Balloon aortic valvuloplasty in 170 consecutive patients

Between October 1, 1985, and April 1, 1988, we performed balloon aortic valvuloplasty in 170 patients (mean age [+/- SD], 77 +/- 5 years) who had symptomatic aortic stenosis. The procedure was completed successfully in 168 patients and resulted in significant increases in the mean (+/- SD) aortic-valve area (from 0.6 +/- 0.2 to 0.9 +/- 0.3 cm2) and cardiac output (from 4.6 +/- 3.4 to 4.8 +/- 1.4 liters per minute) and decreases in the peak aortic-valve pressure gradient (from 71 +/- 20 to 36 +/- 14 mm Hg) (P less than 0.01 for all three comparisons). There were six in-hospital deaths, and five patients required early aortic-valve replacement. Follow-up data were available for all patients, for a period averaging 9.1 months. In addition to the 6 patients who died in the hospital, 25 patients died an average of 6.4 +/- 5.3 months after discharge. Symptoms recurred in 44 patients; they were managed by repeat valvuloplasty in 16 patients, by aortic-valve replacement in 17, and by medical therapy in 11. At the most recent follow-up examination, the symptoms of 103 patients had improved after valvuloplasty; this number includes 15 patients with restenosis who successfully underwent redilation. Life-table analysis indicates that the probability of survival 12 months after the procedure was 74 percent. We conclude that balloon aortic valvuloplasty is an effective palliative therapy for some elderly patients with symptomatic aortic stenosis. Symptoms improve in the majority of patients; although restenosis is common, it can be managed in some patients by repeat balloon dilation.

Temporal dependence of the return of atrial mechanical function on the mode of cardioversion of atrial fibrillation to sinus rhythm

Abstract In conclusion, among patients with a clinical duration of AF of ≤5 weeks, recovery of atrial mechanical function appears related to the mode of cardioversion: a more prompt return of atrial mechanical function was seen in patients undergoing successful pharmacologic cardioversion versus those undergoing successful electrical cardioversion after unsuccessful pharmacologic cardioversion.

Limitations of echocardiographic techniques in evaluation of left atrial masses

Four patients with large left atrial masses documented angiographically or pathologically, or both, were studied with M mode echocardiography (four patients) and two dimensional echocardiography (three patients) within 2 to 5 days of angiographic or pathologic diagnosis. The left atrium appeared clear of echos in two patients subsequently documented to have a left atrial thrombus weighing 35 and 100 g, respectively, and located within the body of the left atrium. Definitely abnormal echoes were visualized in a third patient only in the inferior aspect of the left atrium immediately beneath the posterior root of the aorta. Subsequently, a 70 g left atrial myxoma filling almost the entire left atrium was found. In the fourth patient, who had a 125 g left atrial myxoma, the two dimensional four chamber apical view demonstrated tumor filling almost the entire left atrium. Long axis cross-sectional and M mode echocardiograms less clearly demonstrated the extent of the mass. Even large left atrial tumors located within the body of the left atrium may not be apparent or may be underestimated in size by currently available ultrasonic techniques. The relatively homogenous nature of certain masses may be, in part, responsible for the inability to visualize some of them adequately with echocardiography.

Evaluation of left atrial appendage anatomy and function in recent-onset atrial fibrillation by transesophageal echocardiography

Data regarding left atrial (LA) and LA appendage anatomy and function among patients with newly recognized atrial fibrillation (AF) who have not received long-term warfarin are currently unknown. To identify echocardiographic indexes which characterize those at increased risk for thrombus formation, we analyzed transesophageal echocardiographic studies in 100 consecutive patients with newly recognized AF (duration 2.6 +/- 0.3 week) who had not received long-term warfarin. Fourteen percent of patients had LA thrombi. LA thrombi were associated with larger LA appendages, more depressed LA appendage outflow velocities, and a higher prevalence of severe spontaneous LA contrast. Patients with spontaneous contrast had larger LA and LA appendage anatomy and lower LA appendage ejection velocity. Among patients presenting with their first episode of AF, greater LA appendage ejection and filling velocities and smaller LA and LA appendage sizes were seen among those with AF of <2 weeks duration compared with those with AF of >2 weeks. Thus, patients with recent onset AF and LA thrombi or spontaneous echo contrast have more dilated LA and LA appendage anatomy, and more depressed LA appendage systolic function. Data from patients with their first episode of AF suggests that AF is associated with rapid LA remodeling.

Risk for Valvular Heart Disease among Users of Fenfluramine and Dexfenfluramine Who Underwent Echocardiography before Use of Medication

Fenfluramine and dexfenfluramine, two appetite-suppressant medications, were withdrawn from the market in 1997 after reported associations with valvular heart disease [1-4]. Subsequent echocardiographic surveys suggested that the prevalence of valvular disease is 30% to 38% among medication users; this is substantially higher than the 1% prevalence found in normal persons [1, 5, 6]. One casecontrol study reported a prevalence of 23% among medication users compared with 1% in controls [7]. Defining risk is especially important given the potential morbidity associated with valvular heart disease. Definitive randomized, controlled studies cannot be performed. However, retrospective casecontrol and cohort studies, which are superior to uncontrolled surveys for the estimation of true risk, can be done. To estimate the risk for medication-associated valvular heart disease, we identified users of fenfluramine or dexfenfluramine who underwent echocardiography before beginning therapy with these medications and compared these echocardiograms to those obtained after therapy was discontinued. Methods Patient Selection Patients who were prescribed fenfluramine or dexfenfluramine were identified through medication records at primary care practices affiliated with two academic medical centers in Massachusetts. In general, providers selected patients for therapy on the basis of regional guidelines [8]. Eligible patients used fenfluramine or dexfenfluramine for at least 14 days and underwent echocardiography at the study institutions after 1 January 1988 but before use of diet medication. We obtained consent from physicians and patients according to a protocol approved by the institutional review boards at each study institution. Study Design Clinical data were obtained through chart review and patient interview [9]. Patients were asked about changes in cardiopulmonary symptoms and exercise tolerance by using questions from a validated instrument [10]. A cardiopulmonary examination was performed by an examiner who was blinded to the results of echocardiography. For patients who refused to undergo examination, we abstracted data from the most recent physician examination performed after completion of diet medication therapy. Echocardiography Complete echocardiograms were obtained before and after therapy. All cardiac valves were interrogated with spectral, continuous-wave, and color Doppler echocardiography from multiple views in the standard manner [11, 12] by using mainly Hewlett-Packard Sonos series ultrasonographs (Andover, Massachusetts) with 2.5- to 2.7-MHz transducers and fundamental frequency imaging. The most recent premedication and initial postmedication echocardiograms were reread in a blinded manner by one of two trained echocardiographers. Valvular Abnormalities The following criteria were used to define valvular abnormalities. Mitral or tricuspid valve: Leaflet thickening was assessed as normal, mild, moderate, or severe according to established criteria [13]. Regurgitation was graded by qualitative estimate of the composite color Doppler jet area obtained in at least two of four views and was confirmed by spectral Doppler recordings of high-velocity, holosystolic flow in the left atrium. Regurgitation was graded as trace (jet area < 2 cm2), mild (2 to 5 cm2), moderate (6 to 10 cm2), or severe (> 10 cm2) [11, 12, 14, 15]. Aortic valve: Leaflet thickening criteria were similar to those used for the mitral and tricuspid valves except that thickening could be focal or diffuse. Regurgitation was graded according to the composite jet area obtained in three views and the jet height in the outflow tract and was confirmed by spectral Doppler recordings of high-velocity, diastolic flow in the left ventricular outflow tract. Regurgitation was graded as trace (jet area 1 cm2), mild (2 to 5 cm2), moderate (6 to 10 cm2), or severe (> 10 cm2) [11, 12, 15, 16]. Pulmonic valve: Leaflet thickening criteria were similar to those for the aortic valve. Regurgitation was considered normal (jet area 2 cm2) or abnormal (>2 cm2). Outcome Measures The primary echocardiographic outcome was development of new valvular lesions meeting U.S. Food and Drug Administration (FDA) criteria (at least mild aortic regurgitation or moderate mitral regurgitation) [1] or progression of preexisting valvular disease by at least one degree of severity that also met FDA criteria. A change in severity by one degree was defined as progression from no disease to mild disease, mild disease to moderate disease, or moderate disease to severe disease. Statistical Analysis Descriptive statistics were used to characterize patients in the cohort. The percentage of weight lost was determined by using the patients nadir body weight while taking medication and baseline body weight before taking medication. Paired analysis was used to determine the presence of the primary outcome of new or worsening valvular lesions. Each patients baseline echocardiogram served as the control for any new changes. The 95% CIs were calculated according to the normal approximation of the binomial distribution. To determine the generalizability of results obtained from this cohort, we compared the characteristics (obtained by chart review) of study patients with those of a random 8% sample of patients from the two largest group practices (approximately 80% of study patients) who were prescribed fenfluramine and dexfenfluramine but did not undergo echocardiography before medication use. We also compared enrolled patients with eligible patients who declined to participate. Comparisons were made by using the Fisher exact test for categorical variables and the Wilcoxon rank-sum test for continuous variables. In addition, we analyzed the combined secondary outcome of change in cardiopulmonary symptoms and exercise tolerance or the presence of cardiopulmonary examination findings. Results Patient Enrollment Of 873 patients identified as fenfluramine or dexfenfluramine users, 76 had echocardiography before therapy was started. Physicians excluded 11 patients. Of the 65 remaining patients, 19 declined participation. Of the 46 patients included for analysis, 34 (74%) agreed to be interviewed. The investigators examined 34 (74%) patients; examination data were abstracted from the medical record for 10 of the remaining 12 patients. Patient Characteristics and Generalizability Baseline characteristics did not differ significantly between study patients and nonenrolled eligible patients (Table 1). Compared with a random sample of patients who used diet medications but did not have echocardiography before therapy for comparison, study patients were older (P < 0.001), were more likely to be hypertensive (P = 0.04), and were more likely to have coronary artery disease (P < 0.001). Table 1. Patient Characteristics* Development of Valvular Heart Disease At baseline, eight patients (17.4%) had valvular abnormalities that met FDA criteria; seven (15.2%) had such abnormalities at follow-up. Additional patients had valvular changes that did not meet FDA criteria. Two patients with previous abnormalities that met FDA criteria regressed (Table 2). Two patients with normal mitral and aortic valves developed both mild aortic and mitral thickening at follow-up, two patients developed new mild aortic thickening, and two developed new mild mitral thickening. Table 2. Patients Exhibiting Mitral Regurgitation at Baseline and Follow-up Echocardiography Of 34 patients for whom data were available, 14 (41%) reported new or worsening cardiopulmonary symptoms or exercise intolerance after using diet medications. Of 44 patients for whom physical examination data were available, 24 (54%) had a murmur and 27 (61%) had a murmur or some abnormal physical finding that may reflect valvular abnormality (such as an abnormal heart sound or pedal edema). Of the 46 study patients, 2 (4.3% [95% CI, 0.6% to 14.8%]) developed the primary outcome of new or worsening valvular disease. Both patients were female and had used fenfluramine-phentermine. Neither patient used other diet medications or serotonergic agents. The first patient, who was 52 years of age, had a bicuspid aortic valve and mild aortic regurgitation on a blindly read echocardiogram obtained 1.9 years before medication use. Her follow-up echocardiogram (obtained after 62 days of therapy) showed progression of aortic regurgitation to moderate severity and new mild mitral regurgitation. Her pulmonary artery pressure was elevated (39 mm Hg); no adequate baseline estimate was available. Clinical readings of baseline and follow-up echocardiograms differed from the blinded readings in that aortic regurgitation was read clinically as mild to moderate without interval change. The clinical and blinded readings were otherwise consistent. This patient took fenfluramine-phentermine for 307 days and reduced her initial body mass index (30.5 kg/m2) by 12%. With the exception of a heart murmur that was present before medication use, her interview and physical examination were unremarkable and did not suggest progression of valvular disease. The second patient, who was 66 years of age, had hypothyroidism. An echocardiogram obtained 8.1 years before medication use was normal. A follow-up echocardiogram (obtained after 402 days of therapy) revealed new moderate aortic regurgitation and new mild mitral valve thickening. Her pulmonary artery pressure was elevated at 38 mm Hg on follow-up (no adequate baseline estimate was available). She used fenfluramine-phentermine for 250 days and reduced her initial body mass index (38.9 kg/m2) by 16%. She declined the medical interview and examination; review of her medical record revealed a normal cardiopulmonary examination and no reports of new cardiopulmonary symptoms after medication use. When the 8 patients with FDA-defined valvulopathy before medication use were excluded, the risk for new valvular abnormalities was 2.6% (CI, 0.1% to 13.8%). Among al

Noninvasive assessment of mitral stenosis before and after percutaneous balloon mitral valvuloplasty

Thirty-seven patients with symptomatic mitral stenosis underwent balloon dilatation of the mitral valve. Significant increases (p less than 0.001) were noted in both catheterization- and Doppler-determined valve area (0.9 +/- 0.3 to 1.8 +/- 0.8 and 0.9 +/- 0.2 to 1.7 +/- 0.5 cm2). However, catheterization and Doppler areas before and after valvuloplasty correlated less well (r = 0.51, p less than 0.002 and r = 0.47, p less than 0.005, respectively) than the catheterization-Doppler area correlation in a previous study of 59 consecutive patients with varying degrees of mitral stenosis (r = 0.84, p less than 0.001). Mitral valve area increases were independent of valve thickness estimated using 2-dimensional echocardiography. Flail mitral leaflet movement was not observed and the degree of mitral regurgitation qualitatively assessed using pulsed Doppler mapping techniques increased by greater than 1 of 4 grades in only 1 patient. The lateral mitral valve orifice diameter increased more than the anteroposterior diameter, suggesting commissural splitting as the mechanism of successful valvuloplasty. Increases (all p less than 0.0001) were noted in mitral valve EF slope (7 +/- 5 to 18 +/- 10 mm/s), excursion (11 +/- 5 to 13 +/- 4 mm), S20S interval (0.07 +/- 0.02 to 0.08 +/- 0.02 s) and cardiac output (4.2 +/- 1.3 to 5.3 +/- 2.0 liters/min). There were significant decreases (all p less than 0.001) in left atrial diameter (5.4 +/- 1.0 to 5.1 +/- 1.0 cm), mean catheterization gradient (15 +/- 5 to 8 +/- 4 mm Hg) and mean Doppler gradient (10 +/- 4 to 6 +/- 3 mm Hg).(ABSTRACT TRUNCATED AT 250 WORDS)

Three-dimensional echocardiographic measurement of left ventricular mass: comparison with magnetic resonance imaging and two-dimensional echocardiographic determinations in man.

This study was performed to compare a novel three-dimensional echocardiography (3DE) system to clinical two-dimensional echocardiography (2DE) and magnetic resonance imaging (MRI) for determination of left ventricular mass (LVM) in humans. LVM is an independent predictor of cardiac morbidity and mortality. Echocardiography is the most widely used clinical method for assessment of LVM, as it is non-invasive, portable and relatively inexpensive. However, when measuring LVM, 2DE is limited by assumptions about ventricular shape which do not affect 3D echo. Methods: A total of 25 unselected patients underwent 3DE, 2DE and MRI. Three-dimensional echo used a magnetic scanhead tracker allowing unrestricted selection and combination of images from multiple acoustic windows. Mass by quantitative 2DE was assessed using seven different geometric formulas. Results: LVM by MRI ranged from 91 to 316 g. There was excellent agreement between 3DE and MRI (r = 0.99, SEE = 6.9 g). Quantitative 2D methods correlated well with but underestimated MRI (r = 0.84–0.92) with SEEs over threefold greater (22.5–30.8 g). Interobserver variation was 7.6% for 3DE vs. 17.7% for 2DE. Conclusions: LVM in humans can be measured accurately, relative to MRI, by transthoracic 3D echo using magnetic tracking. Compared to 2D echo, 3D echocardiography significantly improves accuracy and reproducibility.

Dynamic left ventricular outflow tract obstruction when the anterior leaflet is retained at prosthetic mitral valve replacement.

Dynamic left ventricular outflow tract obstruction developed in a patient in whom the anterior leaflet was retained at mitral valve replacement. It was caused by systolic anterior movement of the native anterior leaflet. Reduced outflow tract diameter, resulting from both posterior displacement of the septum and anterior displacement of the native anterior leaflet by porcine stents, was likely instrumental in promoting dynamic obstruction.

Echocardiographic assessment of aortic valve area in elderly patients with aortic stenosis and of changes in valve area after percutaneous balloon valvuloplasty.

Echocardiographic studies, adequate for analysis of aortic valve area using the continuity equation, were obtained in 31 patients aged greater than or equal to 60 years who were undergoing catheterization for assessment of suspected aortic stenosis. Catheterization-determined aortic valve area was 0.74 +/- 0.30 cm2 (mean +/- SD) and Doppler-determined aortic valve areas were 0.68 +/- 0.27 and 0.65 +/- 0.27 cm2, depending on whether peak or mean velocities, respectively, were entered into the continuity equation. There were significant correlations between both of the Doppler-derived and the catheterization-determined aortic valve areas (r = 0.86, p less than 0.001 for both the continuity equation employing peak velocities and the continuity equation employing mean velocities) which were demonstrated to be linear by F test (catheterization area = -0.03 + 1.13 X Doppler area determined using peak velocities, SEE = 0.163 cm2, p less than 0.001; and catheterization area = -0.02 + 1.16 X Doppler area determined using mean velocities, SEE = 0.165 cm2, p less than 0.001). Both sets of correlations had linear regression parameters meeting the conditions for identity. Significant linear correlations were also noted between the non-invasive measurements of aortic valve excursion, ventricular ejection time, time to one-half carotid upstroke, maximal Doppler velocity and maximal Doppler gradient and catheterization aortic valve area, but the correlations were less tight than those between valve areas determined by catheterization and by Doppler continuity equation. Ten of the patients underwent percutaneous balloon aortic valvuloplasty. There were significant linear correlations between aortic valve areas determined by Doppler and catheterization methods both before valvuloplasty (r = 0.77, p = 0.01; p less than 0.001 by F test, SEE = 0.134 cm2) and after valvuloplasty (r = 0.85, p less than 0.01; p = 0.0001 by F test, SEE = 0.161 cm2). Linear regression parameters met the conditions for identity. There was also a significant linear correlation between catheterization and Doppler measurements of absolute change in aortic valve area (r = 0.79, p less than 0.01; p less than 0.001 by F test, SEE = 0.11 cm2). Aortic valve area can be determined reliably by continuity equation in elderly patients. In addition, results of balloon valvuloplasty, measured by changes in catheterization-determined aortic valve area, are accurately reflected by changes in aortic valve area determined using the continuity equation.