Clinical and echocardiographic characteristics of papillary fibroelastomas: a retrospective and prospective study in 162 patients

BACKGROUND

Cardiac papillary fibroelastoma (CPF) is a primary cardiac neoplasm that is increasingly detected by echocardiography. The clinical manifestations of this entity are not well described.

METHODS AND RESULTS

In a 16-year period, we identified patients with CPF from our pathology and echocardiography databases. A total of 162 patients had pathologically confirmed CPF. Echocardiography was performed in 141 patients with 158 CPFs, and 48 patients had CPFs that were not visible by echocardiography (<0.2 cm), leaving an echocardiographic subgroup of 93 patients with 110 CPFs. An additional 45 patients with a presumed diagnosis of CPF were identified. The mean age of the patients was 60+/-16 years of age, and 46.1% were male. Echocardiographically, the mean size of the CPFs was 9+/-4.6 mm; 82.7% occurred on valves (aortic more than mitral), 43.6% were mobile, and 91.4% were single. During a follow-up period of 11+/-22 months, 23 of 26 patients with a prospective diagnosis of CPF that was confirmed by pathological examination had symptoms that could be attributable to embolization. In the group of 45 patients with a presumed diagnosis of CPF, 3 patients had symptoms that were likely due to embolization (incidence, 6.6%) during a follow-up period of 552+/-706 days.

CONCLUSIONS

CPFs are generally small and single, occur most often on valvular surfaces, and may be mobile, resulting in embolization. Because of the potential for embolic events, symptomatic patients, patients undergoing cardiac surgery for other lesions, and those with highly mobile and large CPFs should be considered for surgical excision.

Myxomatous mitral valve chordae. II: Selective elevation of glycosaminoglycan content

BACKGROUND AND AIM OF THE STUDY

Chordal rupture in myxomatous mitral valves is the leading cause of leaflet prolapse and regurgitation. Increased glycosaminoglycan (GAG) content has been reported in these valves. Therefore, the biochemical differences between myxomatous and control mitral valve chordae were investigated.

METHODS

The contents of hexuronic acid, DNA, water, and collagen in chordae from 45 myxomatous valves and 10 control valves were measured. Collagen and hexuronic acid quantities were normalized to wet and dry weights, and to DNA content. Different GAG classes were measured using fluorophore-assisted carbohydrate electrophoresis (FACE).

RESULTS

Myxomatous chordae contained significantly more GAGs than controls after quantities were normalized for wet weight, dry weight, and DNA content. The FACE assay showed that the myxomatous chordae contained significantly more chondroitin/dermatan 6-sulfate when normalized to both wet and dry weight, and slightly more hyaluronan. In contrast to leaflets, which contain predominantly hyaluronan, the predominant GAG class in chordae was chondroitin/dermatan sulfate. Keratan sulfate, a GAG class previously unreported in valve tissues, was also discovered in the chordae. Myxomatous chordae contained more water and less collagen than control chordae, but equal quantities of DNA when normalized for wet weight.

CONCLUSION

Cells in the chordae of myxomatous valves may produce more GAGs than cells in the chordae of control valves. The resulting accumulation of GAGs and bound water likely gives myxomatous valves their characteristic thickening and floppy, gelatinous nature, and may account for their reported mechanical weaknesses.

Myxomatous mitral valve chordae. I: Mechanical properties

BACKGROUND AND AIM OF THE STUDY

Chordal rupture is the most common reason for severe mitral regurgitation requiring surgery. The features that predispose myxomatous chordae to rupture, however, have not been studied. Thus, the physical and mechanical properties of normal and myxomatous mitral valve chordae were measured.

METHODS

Chordae from 24 normal and 59 myxomatous mitral valves were cut into 10 mm-long segments and mechanically tested to measure extensibility, modulus, failure stress, failure strain, and failure load. After testing, the specimens were weighed and their cross-sectional area and volume measured.

RESULTS

Chordae from myxoid mitral valves were larger (1.9 +/- 0.1 mm2 versus 0.8 +/- 0.1 mm2, p < or = 0.001) and heavier (16.6 +/- 1.0 mg versus 6.5 +/- 0.4 mg, p < or = 0.001) than normal chordae. Myxoid chordae had significantly lower moduli (40.4 +/- 10.2 MPa versus 132 +/- 15 MPa, p < or = 0.001) and failed at significantly lower tensile stress (6.0 +/- 0.6 MPa versus 25.7 +/- 1.8 MPa, p < or = 0.001) and absolute load (728 +/- 50 g versus 1,450 +/- 135 g, p < or = 0.001) than normal chordae. Normal and myxoid chordae had similar measurements of extensibility and failure strain.

CONCLUSION

Myxomatous degeneration severely affects the mechanical properties of mitral valve chordae. Most notably, myxoid chordae failed at loads one-half of those of normal chordae. This may explain why chordal rupture is the main indication for repair of myxoid mitral valves. These findings also suggest that chordal preservation should be carried out with caution, as myxoid chordae are clearly abnormal with compromised mechanical strength.

Calculation of mitral regurgitant orifice area with use of a simplified proximal convergence method: initial clinical application

To validate a previously proposed simplified proximal flow convergence method for calculating mitral regurgitant orifice area (ROA), a prospective study was conducted in ambulatory patients and in patients undergoing open heart surgery. Assuming a pressure difference between the left ventricle and left atrium of approximately 100 mm Hg (jet velocity [v(p)] 500 cm/s) and setting the color aliasing velocity (v(a)) to 40 cm/s, we simplified the conventional proximal convergence method formula (ROA = 2pi(r2)v(a)/v(p)) to r2/2, where r is the radius of the proximal convergence isovelocity hemisphere. For 57 ambulatory patients with a wide range of mitral regurgitant severity (1 to 4+), ROA was calculated by the conventional (x) and simplified (y) methods, demonstrating excellent accuracy (r = 0.92; P <.001; DeltaROA [y - x] = 0.004 +/- 0.08 cm2). For 24 intraoperative patients, ROA calculated by the simplified formula (y) correlated well with the pulsed Doppler-thermodilution method (x) (r = 0.84; P <.01; DeltaROA [y - x] = -0.002 +/- 0.08cm2). This simplified proximal convergence formula yields an accurate assessment of ROA for a wide range of regurgitant severity, while the time required for this measurement is shortened by half (1.5 +/- 0.5 minutes versus 3.2 +/- 0.7 minutes). This may increase the frequency of calculating ROA in the clinical laboratory.

Localization of needle tip with color doppler during pericardiocentesis: In vitro validation and initial clinical application

This study evaluates a new device that uses color Doppler ultrasonography to enable real-time image guidance of the aspirating needle, which has not been possible until now. The ColorMark device (EchoCath Inc, Princeton, NJ) induces high-frequency, low-amplitude vibrations in the needle to enable localization with color Doppler. We studied this technique in 25 consecutive patients undergoing pericardiocentesis, and in vitro, in a urethane phantom with which the accuracy of color Doppler localization of the needle tip was compared with that obtained by direct measurement. Tip localization was excellent in vitro; errors axial to the ultrasound beam (velocity Doppler -0.13 +/- 0.90 mm, power Doppler -0.05 +/- 1.7 mm) were less than lateral errors (velocity -0.36 +/- 1.8 mm, power -0.02 +/- 2.8 mm). In 18 of 25 patients, the needle was identified and guided into the pericardial space with the ColorMark technique, and it allowed successful, uncomplicated drainage of fluid. Initial failures were the result of incorrect settings on the echocardiographic machine and inappropriate combinations of the needle puncture site and imaging window. This study demonstrates a novel color Doppler technique that is highly accurate at localizing a needle tip. The technique is feasible for guiding pericardiocentesis. Further clinical validation of this technique is required.

Comparison of cardiovascular risk and lipid profiles in patients undergoing aortic valve surgery versus those undergoing coronary artery bypass grafting

BACKGROUND AND AIM OF THE STUDY

Hyperlipidemia is a risk factor for the progression of coronary artery disease, and possibly also valvular aortic stenosis. Thus, patients with aortic stenosis, coronary disease (or both) might be expected to have more abnormal lipid profiles than those without these two conditions.

METHODS

The lipid profiles of patient subsets undergoing aortic valve replacement (AVR) with or without concomitant coronary artery bypass grafting (CABG), as well as those undergoing isolated CABG, between 1987 and 1997 were analyzed retrospectively. Four surgical groups were identified: AVR for aortic regurgitation (n = 370); AVR for predominant aortic stenosis (n = 1,072); AVR for aortic stenosis (AS) with CABG (n = 914); and isolated CABG (n = 11,156). The complete fasting lipid profiles of patients were collected, analyzed by group, and compared.

RESULTS

Analysis by Spearman's correlation showed that total cholesterol levels, triglycerides and low-density lipoproteins (LDL-C) were modestly, yet significantly, increased in each successive group, while high-density lipoproteins were decreased. AS patients undergoing isolated AVR had significantly higher total cholesterol (215 versus 201 mg/dl; p <0.0001), triglycerides (125 versus 104 mg/dl; p <0.0001) and LDL-C (139 versus 132 mg/dl; p = 0.003) than those undergoing AVR for aortic regurgitation. Total cholesterol >200 mg/dl was significantly associated with AS, even after adjusting for differences in age, sex, diabetes mellitus and hypertension, with an odds ratio of 1.5 (95% confidence interval, 1.2-2.0; p = 0.001).

CONCLUSION

Progressively abnormal lipid profiles are associated with AS and coronary disease in patients undergoing AVR. This evidence helps to extend the link between dyslipidemia and AS in a large consecutive series of patients.

Comparison of quantitative and semiquantitative methods for assessing mitral regurgitation by transesophageal echocardiography

Semiquantitative grading of mitral regurgitation (MR) by transesophageal echocardiography (TEE) is widely used for clinical decision making. However, the relation between semiquantitative grading by biplane or multiplane TEE and quantitative measures remains undetermined. Biplane or multiplane TEE was performed in 113 patients in the operating room. MR severity was graded from 1 to 4+ by Doppler color flow mapping. MR was quantified using the thermodilution-Doppler method as mitral regurgitant stroke volume (RSV) derived from the difference between total mitral inflow measured by pulsed Doppler and forward flow measured by thermodilution. Mitral regurgitant orifice area (ROA) was calculated by RSV divided by mitral regurgitant velocity. RSV and ROA were also calculated using the proximal isovelocity surface area method. RSV and ROA significantly correlated with the semiquantitative grading either by TEE or angiogram in a nonlinear fashion, with the best fit being given by an exponential model with correlation coefficients from 0.73 to 0.87 (p <0.001). Substantially increased RSV and ROA were observed in MR grades of > or =3+. In the same grades of 3+ or 4+ MR, the largest RSV was 4 times larger than the smallest (190 to 220 vs 44 to 45 ml), and the largest ROA (1.82 to 2.0 vs 0.26 to 0.27 cm2) was sixfold larger than the smallest. Patients with 2 to 3+ MR had significantly variable RSV and ROA (range 21 to 91 ml and 0.12 to 0.65 cm2, respectively). Color flow mapping by biplane or multiplane TEE or angiography is able to categorize precisely mild (< or =2+) and severe (> or =3+) MR, but cannot accurately determine actual hemodynamic load of MR in more severe degrees of MR.

Case report: outer sheath rupture may precede complete chordal rupture in fibrotic mitral valve disease

Rupture mechanics of mitral valve chordae have been difficult to elucidate because most surgical repairs and pathological examinations are performed after the rupture. In an excised anterior leaflet from a fibrotic mitral valve, chordae were observed in an initial phase of rupture. Microscopic sections showed that thinned, nearly ruptured chordal segments were actually chordal cores, containing highly aligned collagen fibers. The outer sheath of elastic fibers, disorganized circumferentially oriented collagen fibers, and endothelial cells that normally surrounds the collagen core apparently had retracted to the extreme ends of the thinned segment, resulting in a bulbous shape, as noted in the chordal rupture literature. In conclusion, these new observations lead us to propose that the rupture of mitral valve chordae is not spontaneous, but may occur over time. The failure of the outer sheath may represent the first phase in a slow, two-part process leading to eventual chordal rupture.

Echocardiographic assessment of the mechanisms of correction of bileaflet prolapse causing mitral regurgitation with only posterior leaflet repair surgery

Recent data suggest that posterior leaflet repair alone corrects mitral regurgitation in patients with bileaflet prolapse and normal anterior chordae. The purpose of this study was to use echocardiography to define the anatomic differences between posterior and bileaflet prolapse and to determine if posterior leaflet repair alone leads to correction of bileaflet prolapse. We studied patients who underwent quadrangular resection of the posterior mitral valve leaflet to treat bileaflet prolapse (group I, n = 20) or isolated posterior leaflet prolapse (group II, n = 20). Echocardiographic characteristics were compared before and after the procedure. There were no differences in the left ventricular end-diastolic or end-systolic dimensions or function between the 2 groups. However, anterior leaflet length was greater in patients with bileaflet prolapse (3.3 +/- 0.6 cm vs 2.6 +/- 0.4 cm, p = 0.003). In group I, posterior leaflet repair changed anterior leaflet displacement from -0.8 +/- 0.2 to 0.5 +/- 0.4 cm (p <0.001) and posterior leaflet displacement from -0.8 +/- 0.3 cm below to 0.5 +/- 0.4 cm (p <0.001) in front of the mitral annular plane. In group II, anterior leaflet displacement was unchanged from 0.2 +/- 0.1 to 0.3 +/- 0.2 cm (p = 0.22), whereas posterior leaflet displacement changed from -0.7 +/- 0.2 to 0.4 +/- 0.2 cm (p <0.001). Thus, patients with bileaflet prolapse and no ruptured chords have excessive anterior leaflet length. In such patients, posterior leaflet repair alone corrects anterior and posterior leaflet prolapse.

Prediction of thrombus-related mechanical prosthetic valve dysfunction using transesophageal echocardiography

Identification of thrombus-related mechanical prosthetic valve dysfunction (MPVD) has important therapeutic implications. We sought to develop an algorithm, combining clinical and echocardiographic parameters, for prediction of thrombus-related MPVD in a series of 53 patients (24 men, age 52 +/- 16 years) who had intraoperative diagnosis of thrombus or pannus from 1992 to 1997. Clinical and echocardiographic parameters were analyzed to identify predictors of thrombus and pannus. Prevalence of thrombus and diagnostic yields relative to the number of predictors were determined. There were 22 patients with thrombus, 19 patients with pannus, and 12 patients with both. Forty-two of 53 masses were visualized using transesophageal echocardiography (TEE), including 29 of 34 thrombi or both thrombi and panni and 13 of 19 isolated panni. Predictors of thrombus or mixed presentation include mobile mass (p = 0.009), attachment to occluder (p = 0.02), elevated gradients (p = 0.04), and an international normalized ratio of < or = 2.5 (p = 0.03). All 34 patients with thrombus or mixed presentation had > or = 1 predictor. The prevalence of thrombus in the presence of < or = 1, 2, and > or = 3 predictors is 14%, 69%, and 91%, respectively. Thus, TEE is sensitive in the identification of abnormal mass in the setting of MPVD. An algorithm based on clinical and transesophageal echocardiographic predictors may be useful to estimate the likelihood of thrombus in the setting of MPVD. In the presence of > or = 3 predictors, the probability of thrombus is high.

Transesophageal echocardiographic (TEE) evaluation of ventricular function

Transesophageal echocardiography (TEE) provides excellent delineation of ventricular function in the ambulatory and critical settings. Major indications include the acutely ill patient with suboptimal images with other techniques and the intraoperative assessment of patients undergoing cardiac surgery and of cardiac patients undergoing noncardiac surgery. The methodology of quantification of ventricular function is quite accurate, though it has inherent limitations. Newer technologies, such as edge enhancement techniques, three-dimensional acquisition, and contrast agents, all have the potential to improve evaluation of ventricular function with TEE. Stress imaging with TEE is possible with dobutamine and with pacing techniques. This is sage and accurate, and it is indicated in patients, such as the morbidly obese, who are impossible to image by other methods.

Psychological aspects of chronic tonic and clonic stuttering: suggested therapeutic approaches

A comparison of the personality profiles and intellectual functioning of 12 tonic and 18 clonic stutterers indicated that the groups could be discriminated on measures of verbal IQ, object relations, social isolation, somatization, and cognitive processing. Findings are examined in terms of the impact of type of functioning on maintenance of stuttering, and implications for treatment are discussed.

Improvement in right ventricular systolic function after surgical correction of isolated tricuspid regurgitation

Chronic tricuspid regurgitation (TR) may lead to impairment in right ventricular (RV) function. Whether surgical correction results in restoration of normal RV geometry and function is unknown. The purpose of this study was to determine whether surgical correction of TR results in improved RV geometry and function. Measurements of RV areas were made from digitized 4-chamber echocardiographic views. Right ventricular end-diastolic volume (RVEDV), right ventricular end-systolic volume (RVESV), and ejection fraction (EF) were calculated with the single-plane subtraction method. There was a significant decrease in RVEDV (109.06 +/- 12.45 versus 71.63 +/- 6. 83; P =.005) and RVESV (76.2 +/- 9.83 versus 44.5 +/- 5.58; P =.002) and a significant increase in RVEF (0.30 +/- 0.05 versus 0.38 +/- 0. 05; P =.01) at a mean follow-up of 130 +/- 63 days after surgery. These results demonstrate significant remodeling of the right ventricle with reduction in size and improved EF after tricuspid valve surgery.

Elevated circulating levels of serum tumor necrosis factor-alpha in patients with hemodynamically significant pressure and volume overload

OBJECTIVES

We sought to determine whether serum tumor necrosis factor-alpha (TNF-alpha) levels are elevated in patients with hemodynamically significant pressure and volume overload.

BACKGROUND

It has been previously shown that TNF-alpha messenger ribonucleic acid (mRNA) and protein are rapidly expressed in the hearts of animal models subjected to abrupt hemodynamic overloading. The clinical significance of these experimental findings has not been tested in pathophysiologically relevant clinical models in human subjects.

METHODS

We prospectively measured serum TNF-alpha levels and serum TNF receptor 1 and 2 levels in 21 patients with severe aortic stenosis (AS), in 26 patients with 3+ to 4+ mitral regurgitation (MR) and in normal age- and gender-matched control subjects. Patients with AS and MR were either in New York Heart Association (NYHA) functional class I or II and had no significant coronary disease. We compared the cytokine levels among the groups using analysis of variance. We related cytokine levels to the severity of AS using simple regression analysis.

RESULTS

Serum TNF-alpha levels in patients with AS (2.1 +/- 1.6 pg/ml, n = 21) and MR (1.3 +/-0.7 pg/ml, n = 26) were significantly higher than those in the control subjects (0.7 +/-0.2 pg/ml, n = 28). Serum TNF receptor 1 and 2 levels were also higher in patients with AS and MR than in control subjects. Cytokine levels were higher in patients in NYHA class II than in those in class I. In patients with a normal ejection fraction (>50%, n = 16), there was a mild positive correlation (r = 0.56, p = 0.025) between serum TNF-alpha levels and the mean gradient across the aortic valve.

CONCLUSIONS

This study demonstrates that serum TNF-alpha is elevated in patients with chronic hemodynamic overloading and early cardiac decompensation. Furthermore, these findings suggest not only that peripheral TNF-alpha levels correlate with the severity of the hemodynamic pressure overload, but also that peripheral TNF-alpha and TNF receptor levels increase in direct relation to deteriorating NYHA functional class.

Exercise echocardiographic assessment in severe mitral regurgitation

In chronic severe mitral regurgitation, minimum morbidity and mortality is achieved by applying surgical correction before left ventricular dysfunction becomes irreversible. This requires detection of subtle signs of early ventricular decompensation, for which isotonic stress echocardiography is more accurate than is use of resting indices of contractile function alone. We perform serial 6-monthly stress echocardiography for patients with severe mitral regurgitation, and recommend surgery when the exercise end-systolic volume index or ejection fraction reaches the cutoff values in Table 4 or if there is a clear adverse trend. Exercise echocardiography is more accurate than is exercise electrocardiography for detecting concomitant coronary disease prior to revascularization. Stress testing is also an objective measure of symptoms. Color-Doppler stress echocardiography can detect those patients whose mitral regurgitation worsens (or even develops de novo) with exercise, which can explain unexpected symptoms. Stress echocardiography, therefore, provides a comprehensive and cost-effective evaluation of patients with mitral regurgitation that combines functional, diagnostic, and prognostic information.

Inferior vena caval masses identified by echocardiography

The most common cause of an inferior vena caval mass is renal cell carcinoma that extends through the lumen, occurring in 47 of 62 patients (85%). Detection of an inferior vena caval mass affects the surgical approach requiring cardiopulmonary bypass for resection when the mass extends to the heart.

The value of assessing pulmonary venous flow velocity for predicting severity of mitral regurgitation: A quantitative assessment integrating left ventricular function

Although alteration in pulmonary venous flow has been reported to relate to mitral regurgitant severity, it is also known to vary with left ventricular (LV) systolic and diastolic dysfunction. There are few data relating pulmonary venous flow to quantitative indexes of mitral regurgitation (MR). The object of this study was to assess quantitatively the accuracy of pulmonary venous flow for predicting MR severity by using transesophageal echocardiographic measurement in patients with variable LV dysfunction. This study consisted of 73 patients undergoing heart surgery with mild to severe MR. Regurgitant orifice area (ROA), regurgitant stroke volume (RSV), and regurgitant fraction (RF) were obtained by quantitative transesophageal echocardiography and proximal isovelocity surface area. Both left and right upper pulmonary venous flow velocities were recorded and their patterns classified by the ratio of systolic to diastolic velocity: normal (>/=1), blunted (<1), and systolic reversal (<0). Twenty-three percent of patients had discordant patterns between the left and right veins. When the most abnormal patterns either in the left or right vein were used for analysis, the ratio of peak systolic to diastolic flow velocity was negatively correlated with ROA (r = -0.74, P <.001), RSV (r = -0.70, P <.001), and RF (r = -0.66, P <.001) calculated by the Doppler thermodilution method; values were r = -0.70, r = -0.67, and r = -0.57, respectively (all P <.001), for indexes calculated by the proximal isovelocity surface area method. The sensitivity, specificity, and predictive values of the reversed pulmonary venous flow pattern for detecting a large ROA (>0.3 cm(2)) were 69%, 98%, and 97%, respectively. The sensitivity, specificity, and predictive values of the normal pulmonary venous flow pattern for detecting a small ROA (<0.3 cm(2)) were 60%, 96%, and 94%, respectively. However, the blunted pattern had low sensitivity (22%), specificity (61%), and predictive values (30%) for detecting ROA of greater than 0.3 cm(2) with significant overlap with the reversed and normal patterns. Among patients with the blunted pattern, the correlation between the systolic to diastolic velocity ratio was worse in those with LV dysfunction (ejection fraction <50%, r = 0.23, P >.05) than in those with normal LV function (r = -0.57, P <.05). Stepwise linear regression analysis showed that the peak systolic to diastolic velocity ratio was independently correlated with RF (P <.001) and effective stroke volume (P <.01), with a multiple correlation coefficient of 0.71 (P <.001). In conclusion, reversed pulmonary venous flow in systole is a highly specific and reliable marker of moderately severe or severe MR with an ROA greater than 0.3 cm(2), whereas the normal pattern accurately predicts mild to moderate MR. Blunted pulmonary venous flow can be seen in all grades of MR with low predictive value for severity of MR, especially in the presence of LV dysfunction. The blunted pulmonary venous flow pattern must therefore be interpreted cautiously in clinical practice as a marker for severity of MR.

Anomalous coronary artery, aortic dissection, and acute myocardial infarction

The combination of acute coronary occlusion and aortic dissection because of involvement of one or other coronary vessels in the dissection flap is uncommon. Furthermore, the occurrence of an anomalous coronary artery and its involvement in acute myocardial infarction is even more uncommon. We describe a patient with acute myocardial infarction in whom an acute aortic dissection involved the ostium of an anomalous circumflex artery.

Latent left ventricular dysfunction in patients with mitral regurgitation: feasibility of measuring diminished contractile reserve from a simplified model of noninvasively derived left ventricular pressure-volume loops

BACKGROUND

Assessment of left ventricular (LV) contractility in mitral regurgitation is difficult, and latent systolic dysfunction may be present despite conventional indexes being in the "normal" range. We sought to demonstrate the presence of latent LV dysfunction in mitral regurgitation by showing diminished contractile reserve with the use of simplified pressure-volume loops from noninvasively derived parameters.

METHODS AND RESULTS

We performed exercise echocardiography in 72 patients with isolated mitral regurgitation, minimal or no symptoms, normal resting LV function, and no coronary disease who subsequently underwent uncomplicated valve repair and in 15 healthy subjects. Simplified pressure-volume loops were constructed and LV stroke work was estimated at rest and immediately after exercise. As pressures were estimated, the findings were confirmed with a validated numerical model to estimate stroke work in patients and control subjects. Patients had a higher stroke work than did control subjects at rest (1.45 +/- 0.39 vs 0.92 +/- 0.21 J, P <.001). Eighteen patients had LV dysfunction develop after surgery. Patients with postrepair dysfunction had a significantly lower exercise stroke work (1.79 +/- 0.69) than did patients without (2.28 +/- 0.84 J, P =.02), but there was no difference in resting stroke work (1.48 +/- 0.39 vs 1.44 +/- 0.4, P = not significant). Change in stroke work with exercise was higher in patients with normal postoperative function (0.84 +/- 0.59 J) and control subjects (0.59 +/- 0.36 J) than patients with postoperative dysfunction (0.31 +/- 0.55 J, P =.001). The numerical model confirmed the lower exercise stroke work and change in stroke work in patients with postoperative dysfunction.

CONCLUSIONS

The clinical study and numerical model confirmed diminished contractile reserve in patients who had LV dysfunction develop after uncomplicated mitral valve repair. Diminished contractile reserve may be a preoperative marker of latent contractile dysfunction.

Quantification of mitral regurgitation by automated cardiac output measurement: experimental and clinical validation

OBJECTIVES

To develop and validate an automated noninvasive method to quantify mitral regurgitation.

BACKGROUND

Automated cardiac output measurement (ACM), which integrates digital color Doppler velocities in space and in time, has been validated for the left ventricular (LV) outflow tract but has not been tested for the LV inflow tract or to assess mitral regurgitation (MR).

METHODS

First, to validate ACM against a gold standard (ultrasonic flow meter), 8 dogs were studied at 40 different stages of cardiac output (CO). Second, to compare ACM to the LV outflow (ACMa) and inflow (ACMm) tracts, 50 normal volunteers without MR or aortic regurgitation (44+/-5 years, 31 male) were studied. Third, to compare ACM with the standard pulsed Doppler-two-dimensional echocardiographic (PD-2D) method for quantification of MR, 51 patients (61+/-14 years, 30 male) with MR were studied.

RESULTS

In the canine studies, CO by ACM (1.32+/-0.3 liter/min, y) and flow meter (1.35+/-0.3 liter/min, x) showed good correlation (r=0.95, y=0.89x+0.11) and agreement (deltaCO(y-x)=0.03+/-0.08 [mean+/-SD] liter/min). In the normal subjects, CO measured by ACMm agreed with CO by ACMa (r=0.90, p < 0.0001, deltaCO=-0.09+/-0.42 liter/min), PD (r=0.87, p < 0.0001, deltaCO=0.12+/-0.49 liter/min) and 2D (r=0.84, p < 0.0001, deltaCO=-0.16+/-0.48 liter/min). In the patients, mitral regurgitant volume (MRV) by ACMm-ACMa agreed with PD-2D (r= 0.88, y=0.88x+6.6, p < 0.0001, deltaMRV=2.68+/-9.7 ml).

CONCLUSIONS

We determined that ACM is a feasible new method for quantifying LV outflow and inflow volume to measure MRV and that ACM automatically performs calculations that are equivalent to more time-consuming Doppler and 2D measurements. Additionally, ACM should improve MR quantification in routine clinical practice.

Three-dimensional echocardiographic planimetry of maximal regurgitant orifice area in myxomatous mitral regurgitation: intraoperative comparison with proximal flow convergence

OBJECTIVES

We sought to validate direct planimetry of mitral regurgitant orifice area from three-dimensional echocardiographic reconstructions.

BACKGROUND

Regurgitant orifice area (ROA) is an important measure of the severity of mitral regurgitation (MR) that up to now has been calculated from hemodynamic data rather than measured directly. We hypothesized that improved spatial resolution of the mitral valve (MV) with three-dimensional (3D) echo might allow accurate planimetry of ROA.

METHODS

We reconstructed the MV using 3D echo with 3 degrees rotational acquisitions (TomTec) using a transesophageal (TEE) multiplane probe in 15 patients undergoing MV repair (age 59 +/- 11 years). One observer reconstructed the prolapsing mitral leaflet in a left atrial plane parallel to the ROA and planimetered the two-dimensional (2D) projection of the maximal ROA. A second observer, blinded to the results of the first, calculated maximal ROA using the proximal convergence method defined as maximal flow rate (2pi(r2)va, where r is the radius of a color alias contour with velocity va) divided by regurgitant peak velocity (obtained by continuous wave [CW] Doppler) and corrected as necessary for proximal flow constraint.

RESULTS

Maximal ROA was 0.79 +/- 0.39 (mean +/- SD) cm2 by 3D and 0.86 +/- 0.42 cm2 by proximal convergence (p = NS). Maximal ROA by 3D echo (y) was highly correlated with the corresponding flow measurement (x) (y = 0.87x + 0.03, r = 0.95, p < 0.001) with close agreement seen (AROA (y - x) = 0.07 +/- 0.12 cm2).

CONCLUSIONS

3D echo imaging of the MV allows direct visualization and planimetry of the ROA in patients with severe MR with good agreement to flow-based proximal convergence measurements.

Left and right atrial transport function after the Maze procedure for atrial fibrillation: an echocardiographic Doppler follow-up study

OBJECTIVES

We evaluated atrial transport function after the Maze procedure in long-term follow-up and compared left and right atrial function in Maze patients with that of healthy age-matched controls using echo Doppler techniques.

BACKGROUND

The Maze procedure is designed to eliminate atrial fibrillation, restore normal sinus rhythm, and preserve atrial contraction. Initial data indicate that atrial transport function is restored in most patients undergoing the Maze procedure. The long-term echo Doppler evaluation of patients after the Maze procedure has not been well described.

METHODS

We performed pulsed-wave Doppler and two-dimensional echocardiographic studies on 31 patients (24 men, mean age 53.8 years) who underwent the Maze procedure and who had a follow-up study greater than 3 months (mean 16.5 months) after the procedure. Measurements included peak left ventricular and right ventricular inflow A-wave velocity, maximum and minimum left atrial and right atrial areas, and fractional area change of the left and right atria. Results were compared with those obtained from 15 age-matched control subjects (11 men, mean age 53.8 years).

RESULTS

Twenty-two patients (71%) had left atrial function shown by the presence of left ventricular inflow A-wave, and 25 patients (81%) had right atrial function shown by the presence of right ventricular inflow A-wave on Doppler echocardiography. The left ventricular inflow A-wave velocity was significantly lower than that of age-matched controls (37.5 +/- 15.5 versus 61.0 +/- 13.9 cm/sec; p < 0.001), whereas the right ventricular inflow A-wave velocity did not significantly differ between patients and control subjects (35.4 +/- 9.9 versus 35.3 +/- 4.9 cm/sec; p = Not significant). Although left and right atrial areas decreased significantly after the procedure, there was no significant change in the fractional area change which was smaller in Maze patients than control individuals.

CONCLUSIONS

(1) In long-term follow-up of 16.5 months after the Maze procedure, left atrial systolic function was preserved in 71% of our patients and right atrial systolic function was preserved in 81%; (2) the left ventricular inflow peak A-wave velocity after Maze is considerably less than that in age-matched controls; and (3) left and right atrial sizes decreased after the procedure with no change in the fractional area change. These findings suggest that the Maze procedure is effective in restoring atrial function in the majority of patients; however, restored function is less than in control individuals.

Improvement in mitral regurgitation after aortic valve replacement

This study sought to determine whether there is a quantitative improvement in mitral regurgitation (MR) after aortic valve replacement (AVR) for aortic stenosis (AS) and, if so, the mechanisms for this change. MR frequently accompanies AS. The addition of mitral valve replacement to AVR significantly increases the risk of surgery. Although previous studies have suggested a qualitative improvement in MR severity after AVR, semiquantitative analysis of this improvement has not been documented nor have the underlying mechanisms been examined. We evaluated 28 patients who had undergone 2-dimensional echo and color flow Doppler imaging an average of 1.5 +/- 2.5 months before and 2.5 +/- 4.2 months after AVR. Maximum MR area, MR percentage (MR area/left atrial area), mitral annular area, left atrial area, aortic gradient, and parameters of left ventricular geometry were measured to evaluate MR severity and to assess functional mechanisms for improvement in MR. There was a significant decrease in MR area (5.5 +/- 2.8 cm2 vs 2.5 +/- 1.9 cm2, p < or =0.0001) and MR percentage (25 +/- 11% vs 12 +/- 10% after operation, p < or =0.0001) between preoperative and postoperative studies. There was a significant reduction in aortic gradient, mitral annular area, left atrial area, and left ventricular length postoperatively. In univariate analysis, MR improvement was related to the lower preoperative left ventricular fractional area change (p = 0.027) and to the changes in fractional area change (p = 0.001) and left ventricular systolic area (p = 0.001). Thus, improvement in MR after AVR is related to changes in left ventricular function postoperatively. These data suggest that reduction in MR is due not only to decreased intraventricular pressure, but also to changes in ventricular morphology.

Determinants of functional capacity in chronic mitral regurgitation unassociated with coronary artery disease or left ventricular dysfunction

Impaired functional capacity is common in patients with mitral regurgitation (MR), but the determinants of functional capacity in patients with normal left ventricular (LV) function are unclear. Forty patients with chronic, isolated, nonrheumatic MR with no coronary artery disease underwent exercise echocardiography with continuous expired gas analysis. Cardiac output and regurgitant stroke volume were measured at rest and immediately after exercise by pulsed-wave Doppler echocardiography. For controls, 17 healthy volunteers without MR were also studied. Patients achieved a significantly lower VO2max compared with controls (25.6 +/- 7.7 vs 31.7 +/- 7.7 ml/kg/min, p = 0.008). VO2max showed better correlations with exercise cardiac output than with cardiac output at rest in both patients and controls. Multiple linear regression identified exercise cardiac output (partial r = 0.65), patient age (partial r = -0.56), and gender as independent determinants of VO2max (multiple R = 0.85, p <0.001). Cardiac output at rest, LV ejection fraction, regurgitant stroke volume, and fraction were not significant determinants. With exercise, the regurgitant stroke volume increased in 13 patients and decreased in 27 patients. The former 13 patients had a significantly lower exercise cardiac output (7.4 +/- 2.5 vs 9.4 +/- 2.6 L/min, p = 0.026). Patients who stopped exercise due to dyspnea (n = 7) had a significantly lower exercise cardiac output and VO2max compared with those who stopped due to fatigue (n = 33), with no differences in resting or exercise regurgitant volume. Patients with an increase in LV end-systolic volume with exercise (n = 8) also had a significantly lower exercise cardiac output (6.9 +/- 1.9 vs 9.2 +/- 2.7 L/min, p = 0.037) and showed a trend toward a lower VO2max (21 +/- 7.5 vs 26 +/- 6.4 ml/kg/min, p = 0.07). In patients with chronic MR, exercise cardiac output is the major determinant of VO2max. Regurgitant volume and fraction are not related to functional capacity. Limitations in functional capacity in these patients may be more related to a diminished cardiac reserve than to a large regurgitant volume.

Effects of anesthetic technique on myocardial wall motion abnormalities during abdominal aortic surgery

OBJECTIVE

To assess the impact of regional supplemented general anesthesia (RSGEN) on regional myocardial function during abdominal aortic surgery (AAS).

DESIGN

Prospective randomized study.

SETTING

Single academic medical center.

PARTICIPANTS

Seventy-three patients scheduled for infrarenal aortic aneursymectomy.

INTERVENTIONS

Patients received standardized intraoperative anesthetic management consisting of either general anesthesia (GA; n = 37) or general anesthesia supplemented by epidural anesthesia (RSGEN; n = 36).

MEASUREMENTS AND MAIN RESULTS

Hemodynamic measurements and transesophageal echocardiograms (TEE) were obtained at eight intraoperative times. The electrocardiogram (ECG) was continuously recorded using Holter monitoring. Of the 56 patients with interpretable TEE recordings, 8 of 30 (27%) GA patients and 7 of 26 (27%) RSGEN patients developed new segmental wall motion abnormalities (SWMAs). There was no treatment effect on either the incidence (p = 0.23) or the intensity (p = 0.34) of SWMAs. Cross-clamping of the aorta was associated with the onset of new SWMAs (odds ratio, 8.2; 95% CI, 1.1 to 64; p = 0.04). Among the 63 patients with interpretable Holter recordings, 9 of 34 (26%) GA patients and 9 of 29 (31%) RSGEN patients exhibited intraoperative ischemia. There was no treatment effect on the incidence (p = 0.22) or intensity (p = 0.67) of ECG ischemia.

CONCLUSION

Despite providing modest hemodynamic depression, RSGEN did not reduce the incidence or intensity of either regional myocardial dysfunction or ECG ischemia. New SWMAs were temporally associated with cross-clamping of the aorta and tended to resolve with unclamping.

Left ventricular function after valve repair for chronic mitral regurgitation: predictive value of preoperative assessment of contractile reserve by exercise echocardiography

OBJECTIVES

We evaluated the value of preoperative assessment of left ventricular contractile reserve in predicting ventricular function after valve repair for minimally symptomatic mitral regurgitation.

BACKGROUND

The optimal timing for operation in minimally symptomatic patients with significant mitral regurgitation is controversial. Accurate preoperative assessment of left ventricular function is difficult, and the ability to predict postoperative function is limited. Previous studies in patients undergoing mitral valve replacement may not be applicable in the present era of valve repair.

METHODS

We performed exercise echocardiography in 139 patients with isolated mitral regurgitation and no coronary disease, 74 of whom subsequently underwent uncomplicated valve repair. We measured rest left ventricular end-systolic dimension, end-systolic wall stress and positive first derivative of left ventricular pressure (dP/dt). End-diastolic and end-systolic volumes and ejection fraction were measured preoperatively at rest, immediately after exercise and postoperatively.

RESULTS

Ejection fraction decreased postoperatively to 55 +/- 10% from a rest preoperative value of 64 +/- 9% (p < 0.001). Compared with patients with a postoperative ejection fraction > or = (n = 56), patients with postoperative ejection fraction < 50% (n = 18) had a significantly lower preoperative exercise ejection fraction (57 +/- 11% vs. 73 +/- 9%, p < 0.0005), a larger exercise end-systolic volume index (32 +/- 8 vs. 18 +/- 7 cm3/m2, p < 0.0005) and a lower change in ejection fraction with exercise (-4 +/- 8% vs. 9 +/- 10%, p < 0.005). Preoperative rest indexes, including dP/dt, end-systolic wall stress and end-systolic volume index were less predictive, whereas exercise capacity, rest ejection fraction and end-systolic dimension were not predictive of post-repair ejection fraction. An exercise end-systolic volume index > 25 cm3/m2 was the best predictor of postoperative dysfunction, with a sensitivity and specificity of 83%.

CONCLUSIONS

In minimally symptomatic patients with mitral regurgitation, latent ventricular dysfunction may be indicated by a limited contractile reserve, manifest at exercise as an inadequate increase in ejection fraction and a larger end-systolic volume. These variables may also be used to predict left ventricular function after repair.

Echocardiographic score as a predictor of in-hospital cost in patients undergoing percutaneous balloon mitral valvuloplasty

Percutaneous balloon mitral valvuloplasty (PBMV) is an effective means of palliating mitral stenosis, but it sometimes leads to adverse clinical outcomes and exorbitant in-hospital costs. Because echocardiographic score is known to be predictive of clinical outcome in patients undergoing PBMV, we examined whether it could also be used to predict in-hospital cost. Preprocedure echocardiographic scores, baseline clinical characteristics, and total in-hospital costs were examined among 45 patients who underwent PBMV between January 1, 1992, and January 1, 1994. Patients ranged in age from 18 to 71 years and had preprocedure echocardiographic scores that ranged from 4 to 12. Following PBMV, mean mitral valve area increased from 1.1 +/- 0.3 to 2.4 +/- 0.6 cm2 (p = 0.0001), and mean pressure gradient decreased from 18.3 +/- 5.9 to 6.7 +/- 2.7 mm Hg (p = 0.0001). In-hospital cost for the 45 patients ranged from $3,591 to $70,975 (mean $9,417; median $5,311). Univariate and multiple linear regression analyses demonstrated that among the variables examined, echocardiographic score (p = 0.0007), age (p = 0.01), and preprocedure mitral valve gradient (p = 0.03) were associated with in-hospital cost. Regression modeling suggested that every increase in preprocedure echocardiographic score of one grade was associated with an increase in in-hospital cost of $2,663. Because echocardiographic score is predictive of both clinical outcome and in-hospital cost, we conclude that patients with elevated scores should be considered for alternative therapy.

Myocardial wall velocity assessment by pulsed Doppler tissue imaging: characteristic findings in normal subjects

To validate the use of pulsed Doppler tissue imaging that measures myocardial wall velocities and to define the characteristics of these velocities in normal subjects, we obtained and compared the anteroseptal and posterior wall velocities in 24 volunteers with pulsed Doppler tissue imaging and digitized M-mode echocardiography. We also studied the relation between velocity components and hemodynamic events timed by standard Doppler flows. There was an excellent correlation between Doppler and M-mode-derived velocities (r = 0.95, p < 0.001), with higher reproducibility for Doppler (r = 0.99) than for M-mode (r = 0.95, p < 0.001). Biphasic velocities that were uniformly present during isovolumic contraction and relaxation were attributed to geometric changes due to asynchronous contraction and ventricular interdependence. We conclude that wall velocities obtained by pulsed Doppler tissue imaging are accurate and reproducible. This method may prove useful for studying the contractile and elastic properties of the myocardium.

Assessment of mitral annular dynamics during diastole by Doppler tissue imaging: comparison with mitral Doppler inflow in subjects without heart disease and in patients with left ventricular hypertrophy

The purpose of this study was to determine the normal pattern and magnitude of mitral annular velocities in diastole by Doppler tissue imaging (DTI) and to assess whether this is altered in patients with left ventricular hypertrophy. Mitral annulus velocities were measured by DTI. Peak and time-velocity integral were measured from the DTI tracings and the timing of the velocities in relation to electrocardiogram. DTI was compared with M-mode echo of the annulus and mitral inflow Doppler velocities. Integrated annular velocities by DTI correlated with the annular displacement. Early diastolic velocities decreased with age and in patients with left ventricular hypertrophy. In the hypertrophy group, early diastolic velocities were significantly lower than normal even after correcting for age. Patients with left ventricular hypertrophy also showed a delay in peak early diastolic mitral annular velocity (5.5 +/- 21 msec after the E wave). In conclusion, mitral annular velocity in diastole is readily recorded by DTI. The magnitude and the pattern of these velocities are significantly altered by age and by left ventricular hypertrophy. This method provides a new insight into diastolic filling events and may prove useful in detecting abnormal diastolic function.

Impact of wall constraint on velocity distribution in proximal flow convergence zone. Implications for color Doppler quantification of mitral regurgitation

OBJECTIVES

This study sought to elevate the effect of proximal flow constraint induced by the left ventricular wall on the accuracy of calculated flow rates and to assess a possible correction factor to adjust the proximal convergence angle. We further defined under which hydrodynamic and geometric conditions it is necessary to apply the corrected convergence angle.

BACKGROUND

The proximal flow convergence method has been proposed as a new approach to quantify valvular regurgitation. However, significant overestimation of the calculated regurgitant flow rate has been reported, particularly in patients with mitral valve prolapse and severe mitral regurgitation.

METHODS

We used an in vitro flow model and induced various degrees of proximal flow constraint. The accuracy of the proposed convergence angle formula, alpha = tau + 2 tan-1 d/r (d = wall distance; r = isovelocity radius) was tested in vitro and in a three-dimensional numerical simulation.

RESULTS

With a constraining wall near the orifice, overstimulation of regurgitant flow rates was noted and was most significant with the constraining wall positioned closest to the orifice (calculated flow rate [Qc]/true flow rate [Qo] = 1.85 +/- 0.55 [mean +/- SD]). These findings were similar to the results of the numerical simulation. Applying the correction factor nearly completely eliminated the overestimation of the calculated flow rates (cQc), with cQc/Qo = 1.13 +/- 0.25.

CONCLUSIONS

In the presence of a constraining wall, significant overestimation of calculated flow rates is observed when hemispheric symmetry of the flow field is assumed. In this situation, it is necessary to apply the corrected convergence angle formula to improve the accuracy of the proximal flow convergence method.

Mechanisms of hemolysis with mitral prosthetic regurgitation. Study using transesophageal echocardiography and fluid dynamic simulation

OBJECTIVES

The aims of this study were to define the hydrodynamic mechanisms involved in the occurrence of hemolysis in prosthetic mitral valve regurgitation and to reproduce them in a numeric simulation model in order to estimate peak shear stress.

BACKGROUND

Although in vitro studies have demonstrated that shear stresses > 3,000 dynes/cm2 are associated with significant erythrocyte destruction, it is not known whether these values can occur in vivo in conditions of abnormal prosthetic regurgitant flow.

METHODS

We studied 27 patients undergoing reoperation for significant mitral prosthetic regurgitation, 16 with and 11 without hemolysis. We classified the origin and geometry of the regurgitant jets by using transesophageal echocardiography. By using the physical and morphologic characteristics defined, several hydrodynamic patterns were simulated numerically to determine shear rates.

RESULTS

Eight (50%) of the 16 patients with hemolysis had paravalvular leaks and the other 8 had a jet with central origin, in contrast to 2 (18%) and 9 (82%), respectively, of the 11 patients without hemolysis (p = 0.12, power 0.38). Patients with hemolysis had patterns of flow fragmentation (n = 2), collision (n = 11) or rapid acceleration (n = 3), whereas those without hemolysis had either free jets (n = 7) or slow deceleration (n = 4) (p < 0.001, power 0.99). Numeric simulation demonstrated peak shear rates of 6,000, 4,500, 4,500, 925 and 950 dynes/cm2 in these five models, respectively.

CONCLUSIONS

The distinct patterns of regurgitant flow seen in these patients with mitral prosthetic hemolysis were associated with rapid acceleration and deceleration or high peak shear rates, or both. The nature of the flow disturbance produced by the prosthetic regurgitant lesion and the resultant increase in shear stress are more important than the site of origin of the flow disturbance in producing clinical hemolysis.

Differentiation of constrictive pericarditis from restrictive cardiomyopathy: assessment of left ventricular diastolic velocities in longitudinal axis by Doppler tissue imaging

OBJECTIVES

We sought to determine the utility of left ventricular expansion velocities in differentiating constrictive pericarditis from restrictive cardiomyopathy.

BACKGROUND

Several studies have shown that left ventricular diastolic expansion is influenced by the elastic recoil forces of the myocardium. These forces are affected by intrinsic myocardial disease but should be preserved when diastole is impaired as a result of extrinsic causes.

METHODS

Using Doppler tissue imaging, we measured peak early velocity of longitudinal axis expansion (Ea) in 8 patients with constrictive pericarditis, 7 patients with restriction and 15 normal volunteers. Transmitral early (E) and late (A) Doppler flow velocities, left ventricular systolic and diastolic volumes, ejection fraction and mitral annular M-mode displacement were also compared between the groups.

RESULTS

The Ea value was significantly higher in normal subjects (14.5 +/- 4.7 cm/s [mean +/- SD]) and in patients with constriction (14.8 +/- 4.8 cm/s) than in those with restriction (5.1 +/- 1.4 cm/s, p < 0.001 constriction vs. restriction). There was weak correlation between Ea and the extent of annular displacement (r = 0.55, p = 0.004) and the E/A ratio (r = 0.44, p = 0.03). There was no correlation between Ea and E (r = 0.33, p = 0.07) or ejection fraction (r = 0.21, p = 0.26). By multivariate analysis, Ea was the best variable for differentiating constriction from restriction.

CONCLUSIONS

Our study indicates that longitudinal axis expansion velocities are markedly reduced in patients with restrictive cardiomyopathy. The poor correlation found with transvalvular flow velocities suggests that Ea may be relatively preload independent. The measurement of longitudinal axis expansion velocities provides a clinically useful distinction between constrictive pericarditis and restrictive cardiomyopathy and may prove to be valuable in the study of diastolic function.

Quantification of mitral regurgitation by the proximal convergence method using transesophageal echocardiography. Clinical validation of a geometric correction for proximal flow constraint

BACKGROUND

Proximal flow convergence is a promising method to quantify mitral regurgitation but may overestimate flow when the flow field is constrained. This has not been investigated clinically, nor has a correction factor been validated.

METHODS AND RESULTS

Eighty-five patients were studied intraoperatively with transesophageal echocardiography and divided into two groups: central convergence (no constraining wall) and eccentric convergence (at least one constraining wall). Regurgitant stroke volume (RSV) and orifice area (ROA) were calculated by ROA = 2 pi r2 Va/Vp and RSV = ROA x VTIcw, where r and va are the radius and velocity of the aliasing contour and vp and VTIcw are the peak and integral of regurgitant velocity. In eccentric convergence patients, convergence angle (alpha) was measured from two-dimensional Doppler color flow maps, and ROA and RSV were corrected by multiplying by alpha/180. For reference, RSV was the difference between thermodilution and pulsed Doppler stroke volumes. In central convergence patients (n = 45), RSV (r = .95, delta = 2.5 +/- 10.8 mL) and ROA (r = .96, delta = 0.02 +/- 0.08 cm2) were accurately calculated, but significant overestimation was noted in the eccentric convergence patients (n = 40, delta RSV = 63.9 +/- 38.0 mL, delta ROA = 0.54 +/- 0.31 cm2), 68% of whom had leaflet prolapse or flail. delta RSV was correlated with alpha (r = -.69, P < .001). After correction by alpha/180, overestimation was largely eliminated (delta RSV = 15.5 +/- 19.3 mL and delta ROA = 0.14 +/- 0.14 cm2) with excellent correlation for the whole group (RSV, r = .91; ROA, r = .95).

CONCLUSIONS

A simple geometric correction factor largely eliminates overestimation caused by flow constraint with the proximal convergence method and should extend the clinical utility of this technique.

Intraoperative validation of mitral inflow determination by transesophageal echocardiography: comparison of single-plane, biplane and thermodilution techniques

OBJECTIVES

This study investigated the accuracy of mitral inflow quantification using biplane transesophageal echocardiography.

BACKGROUND

Mitral stroke volume can be reliably quantified by transthoracic Doppler echocardiography, but previous studies involving monoplane transesophageal echocardiography have yielded mixed results.

METHODS

Thirty patients without mitral regurgitation were prospectively examined immediately before cardiovascular surgery. Mitral annulus diameter was measured in the transverse (d1) and longitudinal views (d2) by biplane transesophageal echocardiography. Assuming an elliptic shape, the annular area was calculated as pi d1d2/4; area was also calculated from single-plane data assuming a circular annular shape as pi d2/4. The time-velocity integral of mitral annular Doppler velocity was then multiplied by annular area to yield stroke volume. These data were compared with simultaneous thermodilution measurements by linear regression.

RESULTS

Good correlations were observed between thermodilution (x) and Doppler (y) measurements of stroke volume (SV) (r = 0.86, p < 0.01, delta SV [y-x] = 2.64 +/- 9.86 ml for single four-chamber view; r = 0.77, p < 0.01, delta SV = 1.82 +/- 12.59 ml for two-chamber view; r = 0.94, p < 0.001, delta SV = 1.78 +/- 5.90 ml for biplane measurements) with similar data for cardiac output (r = 0.82, r = 0.74 and r = 0.92, respectively). The biplane measurements were most accurate and had less variability in individual patients (p < 0.05). This finding was supported by a numerical model that demonstrated (for an ellipse of eccentricity 1.5:1) that even maximal misalignment of biplane diameters yielded only 8% area overestimation, whereas single-plane calculations assuming a circular shape produced a variation in area of 225%.

CONCLUSIONS

This study validates the accuracy of measurements of mitral inflow using biplane transesophageal echocardiography with potential application for quantification of valvular regurgitation in the operating room. The results are further generalizable, indicating that orthogonal biplane measurements are both necessary and sufficient to ensure accuracy in area calculation for any elliptic structure.

International physiology. Development of left atrial thrombus following attempted percutaneous mitral valvuloplasty

In this report, we describe two cases of attempted mitral valvuloplasty using an Inoue balloon in which left atrial thrombus was not present before transseptal puncture but developed within minutes of the puncture in one, and within 1 mo in the other, despite systemic anticoagulation.

Comparison of persistent thallium perfusion defects by quantitative washout analysis with thallium reinjection in patients with coronary artery disease

Thallium reinjection can improve the detection of severely ischemic viable myocardium in patients with coronary artery disease. However, a disadvantage of this method is that it requires the acquisition of 3 separate sets of images and the administration of an additional dose of the radiotracer. Alternatively, quantitative analysis of the regional myocardial washout of thallium-201 can be easily obtained from the conventional postexercise and redistribution images without additional imaging time or radiation exposure to the patient. To determine whether this method can predict the results of thallium reinjection, this study analyzed thallium-201 images of 31 patients who had persistent perfusion defects in qualitative exercise/delayed redistribution single-photon emission computed tomographic thallium studies and who underwent thallium reinjection. The quantitative mean radioactive counts of each myocardial segment that had a persistent perfusion defect in the initial and delayed redistribution on 4-hour short-axis tomographic slices were measured to derive a delayed/initial ratio, and these values were compared with the results of thallium reinjection. The delayed/initial ratio was 1.06 +/- 0.22 in 39 segments that improved, versus 0.58 +/- 0.18 in 43 segments without improvement after reinjection (p < 0.001). Thirty-eight of the 39 segments that improved had a ratio of > or = 0.75, versus only 3 of the 43 segments that showed no improvement (sensitivity, 98%; specificity, 91%). The correlation between the delayed/initial ratio and reinjection results was equally high at any segment location or severity. It is concluded that quantitative regional thallium washout analysis predicts the results of thallium reinjection in segments with persistent thallium defects.(ABSTRACT TRUNCATED AT 250 WORDS)

Relationship of aortic regurgitant velocity slope and pressure half-time to severity of aortic regurgitation under changing haemodynamic conditions

The slope and pressure half-time of the aortic regurgitant velocity spectrum have been used as non-invasive markers of regurgitant severity. Recent in vitro and theoretical work, however, has suggested a confounding effect of systemic vascular resistance and left ventricular compliance on these parameters. To study this situation in vivo, we have investigated the determinants of the aortic regurgitant velocity profile in an animal model of aortic regurgitation in which the regurgitation was induced surgically and in which the afterload was varied pharmacologically. Specifically, we examined the relationship of slope and pressure half-time of the aortic regurgitant velocity profile to the severity of aortic regurgitation under varying conditions of afterload using multilinear analysis. Slope varied directly with regurgitant orifice area and inversely with systemic vascular resistance and both left ventricular and aortic compliance (all P < 0.001). Pressure half-time related to these variables in the opposite direction. When the regurgitant orifice was variable in size, slope related directly (P < 0.001) and half-time inversely to the severity of the aortic regurgitation (the clinically expected response). In contrast, when the regurgitant orifice area was constant, slope varied inversely (P < 0.001) and half-time varied directly (P < 0.07) with the severity of the aortic regurgitation. Following nitroprusside infusion, slope tended to increase (P = 0.08) and pressure half-time tended to shorten (P = 0.08) despite a significant reduction in the regurgitant fraction (P = 0.009). Similarly, following dopamine infusion, a significant increase in regurgitant fraction (P = 0.01) was associated with a slight fall in aortic regurgitation slope and a lengthening of the half-time.(ABSTRACT TRUNCATED AT 250 WORDS)

An estimation of the impact of OBRA-87 on nursing home care in the United States

The Omnibus Budget Reconciliation Act of 1987 (OBRA-87) established criteria for Medicare- or Medicaid-certified nursing homes to use in admitting or retaining mentally ill patients. In effect, the law created five dispositional categories for residents or potential residents of nursing homes. Using data from the 1985 National Nursing Home Survey conducted by the National Center for Health Statistics, the authors estimate what proportion of nursing home residents would fall into each of the categories. They suggest that the initial impact of the law will be to shift costs from federal programs to the states. Nursing homes will be expected to provide more mental health services. In the absence of other services, the regulations have a high potential for creating homelessness and continuing a pattern of failure to adequately serve patients with serious mental illness.