Noninvasive assessment of left atrial maximum dP/dt by a combination of transmitral and pulmonary venous flow.
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OBJECTIVES: The study assessed whether hemodynamic parameters of left atrial (LA) systolic function could be estimated noninvasively using Doppler echocardiography. BACKGROUND: Left atrial systolic function is an important aspect of cardiac function. Doppler echocardiography can measure changes in LA volume, but has not been shown to relate to hemodynamic parameters such as the maximal value of the first derivative of the pressure (LA dP/dt(max)). METHODS: Eighteen patients in sinus rhythm were studied immediately before and after open heart surgery using simultaneous LA pressure measurements and intraoperative transesophageal echocardiography. Left atrial pressure was measured with a micromanometer catheter, and LA dP/dt(max) during atrial contraction was obtained. Transmitral and pulmonary venous flow were recorded by pulsed Doppler echocardiography. Peak velocity, and mean acceleration and deceleration, and the time-velocity integral of each flow during atrial contraction was measured. The initial eight patients served as the study group to derive a multilinear regression equation to estimate LA dP/dt(max) from Doppler parameters, and the latter 10 patients served as the test group to validate the equation. A previously validated numeric model was used to confirm these results. RESULTS: In the study group, LA dP/dt(max) showed a linear relation with LA pressure before atrial contraction (r = 0.80, p < 0.005), confirming the presence of the Frank-Starling mechanism in the LA. Among transmitral flow parameters, mean acceleration showed the strongest correlation with LA dP/dt(max) (r = 0.78, p < 0.001). Among pulmonary venous flow parameters, no single parameter was sufficient to estimate LA dP/dt(max) with an r2 > 0.30. By stepwise and multiple linear regression analysis, LA dP/dt(max) was best described as follows: LA dP/dt(max) = 0.1 M-AC +/- 1.8 P-V - 4.1; r = 0.88, p < 0.0001, where M-AC is the mean acceleration of transmitral flow and P-V is the peak velocity of pulmonary venous flow during atrial contraction. This equation was tested in the latter 10 patients of the test group. Predicted and measured LA dP/dt(max) correlated well (r = 0.90, p < 0.0001). Numerical simulation verified that this relationship held across a wide range of atrial elastance, ventricular relaxation and systolic function, with LA dP/dt(max) predicted by the above equation with r = 0.94. CONCLUSIONS: A combination of transmitral and pulmonary venous flow parameters can provide a hemodynamic assessment of LA systolic function. (+info)
Functional anatomy of mitral regurgitation: accuracy and outcome implications of transesophageal echocardiography.
(26/2148)
OBJECTIVES: This study was performed to determine the accuracy and outcome implications of mitral regurgitant lesions assessed by echocardiography. BACKGROUND: In patients with mitral regurgitation (MR), valve repair is a major incentive to early surgery and is decided on the basis of the anatomic mitral lesions. These lesions can be observed easily with transesophageal echocardiography (TEE), but the accuracy and implications for outcome and clinical decision-making of these observations are unknown. METHODS: In 248 consecutive patients operated on for MR, the anatomic lesions diagnosed with TEE were compared with those observed by the surgeon and those seen on 216 transthoracic echocardiographic (TTE) studies, and their relationship to postoperative outcome was determined. RESULTS: Compared with surgical diagnosis, the accuracy of TEE was high: 99% for cause and mechanism, presence of vegetations and prolapsed or flail segment, and 88% for ruptured chordae. Diagnostic accuracy was higher for TEE than TTE for all end points (p < 0.001), but the difference was of low magnitude (<10%) except for mediocre TTE imaging or flail leaflets (both p < 0.001). The type of mitral lesions identified by TEE (floppy valve, restricted motion, functional lesion) were determinants of valve repairability and postoperative outcome (operative mortality and long-term survival; all p < 0.001) independent of age, gender, ejection fraction and presence of coronary artery disease. CONCLUSIONS: Transesophageal echocardiography provides a highly accurate anatomic assessment of all types of MR lesions and has incremental diagnostic value if TTE is inconclusive. The functional anatomy of MR defined by TEE is strongly and independently predictive of valve repairability and postoperative outcome. Therefore, the mitral lesions assessed by echocardiography represent essential information for clinical decision making, particularly for the indication of early surgery for MR. (+info)
Progression of mitral regurgitation: a prospective Doppler echocardiographic study.
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OBJECTIVES: This study was performed to define the rates and determinants of progression of organic mitral regurgitation (MR). BACKGROUND: Severe MR has major clinical consequences, but the rates and determinants of progression of the degree of regurgitation are unknown. Quantitative Doppler echocardiographic methods allow the quantitation of regurgitant volume (RVol), regurgitant fraction (RF) and effective regurgitant orifice (ERO) to define progression of MR. METHODS: In a prospective study of MR progression, 74 patients had two quantitative Doppler echocardiographic examinations of MR (with at least two methods) 561 +/- 423 days apart without an intervening event. RESULTS: Progression of MR was observed, with increase in RVol (77 +/- 46 ml vs. 65 +/- 40 ml, p < 0.0001), RF (47 +/- 16% vs. 43% +/- 15%, p < 0.0001), and ERO (50 +/- 35 mm2 vs. 41 +/- 28 mm2, p < 0.0001). Annual rates (95% confidence interval) were, respectively, 7.4 ml/year (5.1, 9.7), 2.9%/year (1.9, 3.9) and 5.9 mm2/year (3.9, 7.8). However, wide individual variation was observed, and regression and progression of RVol >8 ml was found in 11% and 51%, respectively. In multivariate analysis, independent predictors of progression of RVol were progression of the lesions, particularly a new flail leaflet (p = 0.0003), and progression of mitral annulus diameter (p = 0.0001). Regression of MR was associated with marked changes in afterload, particularly decreased blood pressure (p = 0.008). No significant effect of treatment was detected. CONCLUSIONS: Organic MR tends to progress over time with increase in volume overload (RVol) due to increase in ERO. Progression of MR is variable and determined by progression of lesions or mitral annulus size. These data should help plan follow up of patients with organic MR and future intervention trials. (+info)
Technical aspects of mitral valve replacement with an allograft for acute bacterial endocarditis.
(28/2148)
Mitral valve replacement with a mitral valve allograft is receiving a resurgence of interest. We discuss the technical aspects of this procedure as it applies to cases of acute bacterial endocarditis infecting the mitral valve. (+info)
Replacement of an immobile prosthetic mitral valve: a case report.
(29/2148)
A mechanical prosthetic heart valve can become acutely obstructed despite anticoagulation therapy. This can be a life-threatening complication. We report the case of a 38-year-old woman who survived obstruction of her Sorin prosthetic mitral valve. She was admitted to the hospital because of severe pulmonary edema. On auscultation, mechanical valve sounds were absent. Transthoracic echocardiography showed an immobile mechanical valve. The patient suffered a cardiac arrest while being prepared for surgery, but she underwent successful mitral valve replacement after cardiopulmonary resuscitation. When patients with prosthetic mitral valves present with acute dyspnea, the possibility of an obstructed prosthetic valve must be considered in the differential diagnosis. (+info)
Isometric tension development and its calcium sensitivity in skinned myocyte-sized preparations from different regions of the human heart.
(30/2148)
OBJECTIVE: In this study we investigated whether differences exist or develop in patients with aortic or mitral valve disease in myofibrillar contractile function and contractile protein composition between subendo- and subepicardial human ventricular tissue. Isometric tension, its calcium sensitivity and contractile protein composition were studied in left ventricular subendo- and subepicardial and in atrial biopsies obtained during open heart surgery from 24 patients with mitral or aortic valve disease. METHODS: Isometric tension was measured in mechanically isolated skinned myocyte-sized preparations at different free calcium concentrations at 15 degrees C. Protein composition was analysed by one-dimensional gel electrophoresis. A comparison was made between the results of subendo- and subepicardial ventricular tissue within each New York Heart Association class and within the different hemodynamically overloaded groups. RESULTS: Maximal isometric tension was significantly lower in atrial than in ventricular preparations. The concentration of calcium required for half-maximal activation was significantly higher in atrial than in ventricular preparations. Within the ventricle no differences were found in contractile protein composition, isometric tension and its calcium sensitivity between subendo- and subepicardial tissue when all patients were treated as one group or when patients were subdivided according to severity of heart disease or hemodynamic overload. CONCLUSIONS: In this group of patients with ventricular volume or pressure overload no regional differences exist or develop during cardiac disease in left ventricular myofibrillar protein composition and force production. Maximal isometric tension and its calcium sensitivity are smaller in atrial than in ventricular preparations. (+info)
Evaluation of the hemodynamic relationship between the left atrium and left ventricle during atrial systole by pulsed tissue Doppler imaging in patients with left heart failure.
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The objective of the present study was to evaluate the hemodynamic relationship between the left atrium (LA) and left ventricle (LV) during atrial systole in the presence of an elevated left ventricular end-diastolic pressure (LVEDP) and LV failure using pulsed tissue Doppler imaging (TDI). Fifty-three patients with LV systolic dysfunction and no regional LV asynergy were divided into 3 groups: relaxation failure group (RF, n=20) with a ratio of peak early diastolic to atrial systolic velocity of the transmitral flow (E/A) < or = 1; pseudonormalization group (PN, n=19) with 1 or =2. In addition, 20 normal patients (E/A > or = 1) were studied as a control group. The transmitral and pulmonary venous flow velocities were recorded by transesophageal pulsed Doppler echocardiography. The wall motion velocity patterns were recorded at the middle portion of the LV posterior wall (LVPW) and at the mitral annulus (MA) of the LVPW site in the apical LV long-axis view by transthoracic pulsed TDI. The LVEDP was significantly greater in the PN and RS groups than in the RF and control groups. The moan pulmonary capillary wedge pressure was greatest in the RS group. The percent fractional change of the LA area during atrial systole determined by 2-dimensional echocardiography was significantly lower in the RS group than in the PN group. The peak atrial systolic pulmonary venous flow velocity was significantly greater in the PN group than in the RS group. The peak atrial systolic motion velocity (Aw) at the LVPW was significantly lower in the PN and RS groups than in the RF and control groups. The Aw at the MA was significantly lower in the RS group than in the other groups. There was no significant difference in Aw between the LVPW and MA in the RS group, whereas Aw at the MA was significantly greater than that at the LVPW in the PN group. In conclusion, the measurements of Aw at the LVPW and MA can be used to noninvasively evaluate the hemodynamic relationship between the LA and LV during atrial systole in patients with LV failure. (+info)
Predictors of the long-term outcome after combined aortic and mitral valve surgery.
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BACKGROUND: The influence of preoperative clinical, hemodynamic, and surgical procedures on long-term prognosis after combined aortic and mitral valve surgery is not well known. METHODS AND RESULTS: One hundred seventy patients (mean age, 50.5 years; 102 men and 68 women) who underwent surgery for chronic combined aortic and mitral valvular disease between 1975 and 1989 were followed up for an average of 10.6 years. Additional repair of tricuspid valve was performed in 29 patients (17%), and aortocoronary bypass graft surgery was performed in 7 patients (4.1%). The perioperative mortality rate was 4%, and 10- and 20-year survival rates were 61% and 33%. Only 12 of 94 deaths (11%) were non-cardiac related. At 10 and 20 years, 57% and 21% of patients were free of reoperation, respectively. The main predictors of late survival in univariate analysis were age at surgery (P=0.0002), preoperative left ventricular ejection fraction (P=0.002), cardiac index (P=0.007), tricuspid surgery (P=0.03), pulmonary vascular resistance (P=0.03), NYHA class (P=0.04), and additional aortocoronary bypass graft surgery (P=0.04). Duration of symptoms, gender, cause of valvular disease, and type of prosthesis were not predictive of postoperative outcome. In multivariate stepwise Cox analysis, ejection fraction (P=0.0008), age at surgery (P=0.0011), and tricuspid surgery (P=0. 007) were independent predictors of late survival. CONCLUSIONS: In combined aortic and mitral valve disease, preoperative myocardial function is the main predictor of long-term survival. Low operative mortality rates and good late outcome make valve replacement mandatory before deterioration of myocardial function occurs. Additional tricuspid valve disease requiring surgery significantly decreases the late survival rate. (+info)