Search PubMed⌕ Search

Biomedical subjects

M K Pasque

Publications and source records attributed to M K Pasque.

At least 19 recordsLinked to original sources
PubMed2001

Mechanism underlying mechanical dysfunction in the border zone of left ventricular aneurysm: a finite element model study.

BACKGROUND: The global left ventricular dysfunction characteristic of left ventricular aneurysm is associated with muscle fiber stretching in the adjacent noninfarcted (border zone) region during isovolumic systole. The mechanism of this regional dysfunction is poorly understood. METHODS: An anteroapical transmural myocardial infarct was created by coronary arterial ligation in an adult Dorset sheep and was allowed to mature into left ventricular aneurysm for 10 weeks. The animal was imaged subsequently using magnetic resonance imaging with simultaneous recording of intraventricular pressures. A realistic mathematical model of the three-dimensional ovine left ventricle with an anteroapical aneurysm was constructed from multiple short-axis and long-axis magnetic resonance imaging slices at the beginning of diastolic filling. RESULTS: Three model simulations are presented: (1) normal border zone contractility and normal aneurysmal material properties; (2) greatly reduced border zone contractility (by 50%) and normal aneurysmal material properties; and (3) greatly reduced border zone contractility (by 50%) and stiffened aneurysmal material properties (by 1000%). Only the latter two simulations were able to reproduce experimentally observed stretching of border zone fibers during isovolumic systole. CONCLUSIONS: The mechanism underlying mechanical dysfunction in the border zone region of left ventricular aneurysm is primarily the result of myocardial contractile dysfunction rather than increased wall stress in this region.

Animals↗
PubMed2001

Does the extent of proximal or distal resection influence outcome for type A dissections?

BACKGROUND: The extent of proximal and distal aortic resection that should be performed for acute type A aortic dissections remains controversial. METHODS: From 1984 to 1999, 119 patients underwent repair of an acute type A dissection. Distal resection was to the ascending aorta in 78 (66%) and hemiarch in 41 (34%) patients. Proximally, the aortic valve was preserved in 69 (58%) patients, 40 (34%) underwent composite valve grafting, and 10 (8%) underwent separate graft and valve replacement. RESULTS: Operative mortality was higher for separate graft and valve (50%+/-16%) than for valve preservation (16%+/-5%) or composite grafts (20%+/-7%) (p < 0.05). Hemiarch replacement did not increase operative risk compared to distal reconstruction to the ascending aorta (17%+/-6% versus 22%+/-5%, p > 0.71). At 10 years, freedom from reoperation was 81%+/-7% and long-term survival was 60%+/-8%, but neither was related to the proximal or distal surgical technique (p > 0.15). Risk factors for late reoperation included a nonresected primary tear and Marfan syndrome (p < 0.05). CONCLUSIONS: An aggressive surgical approach, including a full root or hemiarch replacement, is not associated with increased operative risk and should be considered when type A dissections extensively involve the valve, sinuses, or arch.

Acute Disease↗
PubMed2001

Influence of internal mammary artery grafting and completeness of revascularization on long-term outcome in octogenarians.

BACKGROUND: It has been well established that complete revascularization with internal mammary artery (IMA) grafting is important in young patients undergoing coronary artery bypass grafting (CABG). Applying these principles to octogenarians remains controversial. METHODS: From 1986 to 1999, 358 consecutive patients aged 80 to 94 years underwent CABG. Revascularization was complete in 291 (81%) and incomplete in 67 (19%). The IMA was used in 231 (65%) cases. RESULTS: Operative mortality was 7% +/- 1%, but was not statistically different with or without IMA grafting (IMA 5% +/- 2% versus no IMA 10% +/- 3%, p = 0.11) or complete revascularization (p > 0.41). Midterm survival improved with IMA grafting (70% +/- 3% versus 56% +/- 5% at 4 years, p < 0.03; 36% +/- 4% versus 29% +/- 5% at 8 years, p < 0.08), but was not significant beyond 8 years. Among 138 survivors, those with IMA grafts were more likely to be angina free (82% versus 53%, p < 0.001) and in New York Heart Association class I (60% versus 36%, p < 0.03). Survival, recurrent angina, and functional class were independent of completeness of revascularization (p > 0.21). CONCLUSIONS: IMA grafting improved survival, angina, and functional class of octogenarians, but complete revascularization did not have a similar impact.

Aged↗
PubMed2000

Quality of life after aortic valve replacement at the age of >80 years.

BACKGROUND: The optimal management of aortic valve disease in patients >80 years old depends on functional outcome as well as operative risks and late survival. METHODS AND RESULTS: We retrospectively identified 133 patients (62 men, 71 women) aged 80 to 91 years (mean 84+/-3 years) who underwent aortic valve replacement alone or in combination with another procedure between January 1, 1993, and April 31, 1998. Demographics included hypertension 68%, diabetes mellitus 17%, and history of stroke 11%. Operative (30 day) mortality rate was 11%. Urgent or emergent surgery, aortic insufficiency, and perioperative stroke or renal dysfunction were risk factors for operative death by multivariable analysis. Intensive care unit and total hospital length of stay were prolonged at 6.2 and 14.7 days, respectively. Late follow-up between July 1, 1998, and November 1, 1999, was 98% complete. Actuarial survival at 1 and 5 years was 80% and 55%, respectively. Predictors of late mortality were preoperative or perioperative stroke, chronic obstructive pulmonary disease, aortic stenosis, and postoperative renal dysfunction. The mean New York Heart Association functional class for 65 long-term survivors improved from 3.1 to 1.7. Quality of life assessed with the Medical Outcomes Study Short Form-36 was comparable to that predicted for the general population >75 years old. CONCLUSIONS: Functional outcome after aortic valve replacement in patients >80 years old is excellent, the operative risk is acceptable, and the late survival rate is good. Surgery should not be withheld from the elderly on the basis of age alone.

Age Factors↗
PubMed2000

Options for repair of a bicuspid aortic valve and ascending aortic aneurysm.

BACKGROUND: Intrinsic abnormality of the aortic wall may explain the association of bicuspid aortic valves with ascending aortic aneurysms. Separate valve and graft repair of such lesions, rather than composite valve graft replacement, is more straightforward but leaves potentially abnormal sinuses behind. METHODS: Between January 1985 and January 1998, 45 patients underwent separate valve and graft (n = 27) or composite valve graft (n = 18) for an ascending aortic aneurysm and bicuspid aortic valve. Perioperative events and late results were compared. RESULTS: Patients undergoing separate valve and graft were older (mean age, 60 +/- 13 vs 42 +/- 12 years, p < 0.001) and were more likely to have purely stenotic (48% vs 6%, p = 0.003) than purely regurgitant (11% vs 72%, p < 0.001) disease. They were also more likely to require concomitant coronary artery bypass grafting (56% vs 6%, p = 0.001). There were no significant differences in operative risk and no known late complications related to recurrent aneurysms. CONCLUSIONS: Root replacement with a composite valve graft can be accomplished with low operative risk and is the first choice for repair of this lesion. Separate valve and graft repair, however, yields satisfactory early and late results and remains an acceptable option, especially when the coronary ostea are not displaced or when concomitant procedures must be performed.

Adult↗
PubMed2000

Epicardial suction: a new approach to mechanical testing of the passive ventricular wall.

The lack of an appropriate three-dimensional constitutive relation for stress in passive ventricular myocardium currently limits the utility of existing mathematical models for experimental and clinical applications. Previous experiments used to estimate parameters in three-dimensional constitutive relations, such as biaxial testing of excised myocardial sheets or passive inflation of the isolated arrested heart, have not included significant transverse shear deformation or in-plane compression. Therefore, a new approach has been developed in which suction is applied locally to the ventricular epicardium to introduce a complex deformation in the region of interest, with transmural variations in the magnitude and sign of nearly all six strain components. The resulting deformation is measured throughout the region of interest using magnetic resonance tagging. A nonlinear, three-dimensional, finite element model is used to predict these measurements at several suction pressures. Parameters defining the material properties of this model are optimized by comparing the measured and predicted myocardial deformations. We used this technique to estimate material parameters of the intact passive canine left ventricular free wall using an exponential, transversely isotropic constitutive relation. We tested two possible models of the heart wall: first, that it was homogeneous myocardium, and second, that the myocardium was covered with a thin epicardium with different material properties. For both models, in agreement with previous studies, we found that myocardium was nonlinear and anisotropic with greater stiffness in the fiber direction. We obtained closer agreement to previously published strain data from passive filling when the ventricular wall was modeled as having a separate, isotropic epicardium. These results suggest that epicardium may play a significant role in passive ventricular mechanics.

Animals↗
PubMed1998

MRI-radiofrequency tissue tagging in patients with aortic insufficiency before and after operation.

BACKGROUND: Magnetic resonance imaging tissue tagging is a relatively recent methodology that describes ventricular systolic function in terms of intramyocardial ventricular deformation. Because the analysis involves the use of many intramyocardial points to describe systolic deformation, it is theoretically more sensitive at describing subtle differences in regional myocardial fiber shortening when compared with conventional measures of ventricular function such as wall thickening. The objectives of this study were (1) to define sensitive indices of ventricular systolic deformation to assist the clinician in the surgical evaluation of patients with aortic insufficiency, and (2) to quantify differences in regional systolic deformation before and after surgery for aortic insufficiency. METHODS: Magnetic resonance imaging with tissue tagging was performed on 10 normal volunteers and 8 patients with chronic severe aortic insufficiency. Follow-up postoperative studies (5.4+/-1.1 months) were obtained in 6 patients who underwent Ross procedure (1 patient), David procedure (1), and St. Jude aortic valve replacement (4). RESULTS: There was no significant difference in fractional area change, overall circumferential shortening, or overall radial thickening among the normal group, the preoperative aortic insufficiency group, or the postoperative aortic insufficiency group. However, on a regional basis, there was a decrease in posterior wall circumferential strains in the postoperative aortic insufficiency group (29%+/-13% preoperative aortic insufficiency (n=6) versus 24%+/-12% postoperative aortic insufficiency (n=6), p=0.02). CONCLUSIONS: On regional analysis, there was a small but significant decrease in posterior wall circumferential shortening after operation. Magnetic resonance imaging tissue tagging is a sensitive and clinically applicable method of quantifying regional ventricular wall function before and after intervention for aortic insufficiency.

Adult↗
PubMed1997

Previous coronary artery bypass grafting is not a risk factor for aortic valve replacement.

BACKGROUND: The risk of aortic valve replacement (AVR) after previous coronary artery bypass grafting (CABG) is controversial. Its magnitude influences the threshold for recommending this procedure and has been cited in arguments regarding the optimal management of mild aortic stenosis at primary CABG. We therefore reviewed our experience with reoperative AVR +/- CABG and the primary combined procedure. METHODS: Between January 1, 1985, and June 30, 1996, 427 patients underwent primary AVR+CABG, and 52 underwent AVR +/- CABG after prior CABG. Demographics, operative characteristics, and operative results were compared between groups. Data for all patients were pooled and analyzed collectively for risk factors influencing mortality. RESULTS: The extent of native coronary artery disease and the incidence of prior myocardial infarction and stroke were greater in the reoperative group. Aortic cross-clamp and cardiopulmonary bypass times were slightly shorter, and fewer distal anastomoses were performed in the reoperative group. Operative mortality (primary group, 6.3% versus reoperative group, 7.4%) and morbidity were similar. Stepwise multivariate logistic regression analysis identified age, perioperative myocardial infarction, intraaortic balloon support, ventricular arrhythmia, perioperative stroke, and development of renal failure or acute respiratory distress syndrome, but not reoperative status, as predictors of mortality. CONCLUSIONS: The risk of AVR after previous CABG is similar to that for primary AVR+CABG. Valve replacement should, therefore, be pursued despite prior CABG when hemodynamically significant aortic stenosis develops. Furthermore, a circumspect approach to "prophylactic" AVR for mild aortic stenosis at primary CABG seems warranted.

Age Factors↗
PubMed1997

Routine sternal closure using six overlapping figure-of-8 wires.

Contemporary cardiac surgery patients have an increased incidence of risk factors that adversely affect sternal healing. We recommend routine closure of all sternotomy incisions using six overlapping figure-of-8 wire sutures. This augmented closure is simple and effective in counteracting all forces that would delay or disrupt sternal union.

Bone Wires↗
PubMed1996

Magnetic resonance imaging provides evidence for remodeling of the right ventricle after single-lung transplantation for pulmonary hypertension.

BACKGROUND: In end-stage pulmonary hypertension (PH), the degree of right ventricular (RV) dysfunction has been considered so severe as to require combined heart-lung transplantation. Nevertheless, left ventricular (LV) and RV hemodynamics return to relatively normal levels after single-lung transplantation (SLT) alone. Accordingly, to test the hypothesis that LV and RV systolic function improves after SLT and that the dilated, thick-walled RV reverts to more normal geometry, we used cine MRI and finite-element (FE) analysis to study patients with end-stage PH. METHODS AND RESULTS: Seven patients with end-stage PH underwent cine MRI before and after SLT, and eight normal volunteers were also imaged with cine MRI. Short-axis images at the midventricular level were analyzed with customized image-processing software. The LV and RV ejection fractions, velocity of fiber shortening, RV end-diastolic (ED) and end-systolic (ES) chamber areas, and RV ES and ED wall thicknesses were calculated directly from the MRI images. Two-dimensional FE models of the heart were constructed from the MRI images at early diastole. LV and RV pressures were measured in the patients with a cardiac catheterization before and after SLT. Models were solved to yield diastolic LV, RV, and septal wall stresses. By use of a nonlinear optimization algorithm, LV and RV diastolic maternal properties were determined by minimization of the leastsquares difference between FE model-predicted and MRI-measured LV, RV, and epicardial chamber areas and circumferences. The results demonstrated a substantial reduction in RV wall stress after SLT (1.8 x 10(5) dynes/cm2 pre-SLT to 2 x 10(4) dynes/cm2 post-SLT; P < .001). The average RV diastolic elastic modulus was reduced significantly after SLT (1.5 x 10(6) dynes/cm2 pre-SLT to 1 x 10(5) dynes/cm2 post-SLT; P = .01), but there was no change in the LV elastic modulus. RV velocity of fractional shortening increased significantly after SLT (0.23 pre-SLT to 0.58 post-SLT, P = .02), and RV ED and ES wall thicknesses were reduced significantly (ED, 0.86 cm pre-SLT to 0.65 cm post-SLT, P = .03 and ES, 1.06 cm pre-SLT to 0.72 cm post-SLT, P = .005). CONCLUSIONS: These results provide evidence supporting the contention that LV and RV systolic function improved after SLT for end-stage PH and that the RV underwent significant remodeling within 3 to 6 months after lung transplantation.

Adolescent↗
PubMed1996

Myocardial material property determination in the in vivo heart using magnetic resonance imaging.

OBJECTIVES: To determine nonlinear material properties of passive, diastolic myocardium using magnetic resonance imaging (MRI) tissue-tagging, finite element analysis (FEA) and nonlinear optimization. BACKGROUND: Alterations in the diastolic material properties of myocardium may pre-date the onset of or exist exclusive of systolic ventricular dysfunction in disease states such as hypertrophy and heart failure. Accordingly, significant effort has been expended recently to characterize the material properties of myocardium in diastole. The present study defines a new technique for determining material properties of passive myocardium using finite element (FE) models of the heart, MRI tissue-tagging and nonlinear optimization. This material parameter estimation algorithm is employed to estimate nonlinear material parameter sin the in vivo canine heart and provides the necessary framework to study the full complexities of myocardial material behavior in health and disease. METHODS AND RESULTS: Material parameters for a proposed exponential strain energy function were determined by minimizing the least squares difference between FE model-predicted and MRI-measured diastolic strains. Six mongrel dogs underwent MRI imaging with radiofrequency (RF) tissue-tagging. Two-dimensional diastolic strains were measured from the deformations of the MRI tag lines. Finite element models were constructed from early diastolic images and were loaded with the mean early to late left ventricular and right ventricular diastolic change in pressure measured at the time of imaging. A nonlinear optimization algorithm was employed to solve the least squares objective function for hte material parameters. Average material parameters for the six dogs were E = 28,722 +/- 15984 dynes/cm2 and c = 0.00182 +/- 0.00232 cm2/dyne. CONCLUSION: This parameter estimation algorithm provides the necessary framework for estimating the nonlinear, anisotropic and non-homogeneous material properties of passive myocardium in health and disease in the in vivo beating heart.

Algorithms↗
PubMed1996

Spline surface interpolation for calculating 3-D ventricular strains from MRI tissue tagging.

A method is developed and validated for approximating continuous smooth distributions of finite strains in the ventricles from the deformations of magnetic resonance imaging (MRI) tissue tagging "tag lines" or "tag surfaces." Tag lines and intersections of orthogonal tag lines are determined using a semiautomated algorithm. Three-dimensional (3-D) reconstruction of the displacement field on tag surfaces is performed using two orthogonal sets of MRI images and employing spline surface interpolation. The 3-D regional ventricular wall strains are computed from an initial reference image to a deformed image in diastole or systole by defining a mapping or transformation of space between the two states. The resultant mapping is termed the measurement analysis solution and is defined by determining a set of coefficients for the approximating functions that best fit the measured tag surface displacements. Validation of the method is performed by simulating tag line or surface deformations with a finite element (FE) elasticity solution of the heart and incorporating the measured root-mean-square (rms) errors of tag line detection into the simulations. The FE-computed strains are compared with strains calculated by the proposed procedure. The average difference between two-dimensional (2-D) FE-computed strains and strains calculated by the measurement analysis was 0.022 +/- 0.009 or 14.2 +/- 3.6% of the average FE elasticity strain solution. The 3-D displacement reconstruction errors averaged 0.087 +/- 0.002 mm or 2.4 +/- 0.1% of the average FE solution, and 3-D strain fitting errors averaged 0.024 +/- 0.011 or 15.9 +/- 2.8% of the average 3-D FE elasticity solution. When the rms errors in tag line detection were included in the 2-D simulations, the agreement between FE solution and fitted solution was 24.7% for the 2-D simulations and 19.2% for the 3-D simulations. We conclude that the 3-D displacements of MRI tag lines may be reconstructed accurately; however, the strain solution magnifies the small errors in locating tag lines and reconstructing 3-D displacements.

Animals↗
PubMed1995

Single lung transplantation for pulmonary hypertension. Single institution experience in 34 patients.

BACKGROUND: The present study considered the uniformity and durability of the cardiopulmonary response to single lung transplantation in patients with severe pulmonary hypertension, as well as its effect on length and quality of survival. METHODS AND RESULTS: Thirty-four patients with pulmonary hypertension underwent evaluation, single lung transplantation, and follow-up assessment between November 1, 1989, and June 1, 1994. Operative survival for the entire group of patients was reasonable, with 91% (31 of 34 patients) surviving and being discharged from the hospital following transplantation. The actuarial survival for these 34 patients at 1-, 2-, and 3-year follow-up was 78%, 66%, and 61%, respectively. In the subgroup of 24 patients with primary pulmonary hypertension (PPH), 96% (23 of 24) were successfully discharged from the hospital after transplantation. The actuarial survival for this isolated PPH subgroup at 1-, 2-, and 3-year follow-up was 87%, 76%, and 68%, respectively. The uniform, early posttransplant normalization of pulmonary vascular resistance and right ventricular ejection fraction appears to persist throughout the 4-year follow-up period. Despite a high prevalence of bronchiolitis obliterans, the majority of survivors remain in New York Heart Association functional class I or II and are employed. CONCLUSIONS: Single lung transplantation can be performed in patients with end-stage pulmonary vascular disease with reasonable expectations for a relatively low operative mortality; immediate, complete, and durable amelioration of pulmonary hypertension and right ventricular failure; and optimal use of limited donor organ supply.

Actuarial Analysis↗
PubMed1995

Mechanical dysfunction in the border zone of an ovine model of left ventricular aneurysm.

BACKGROUND: The pathophysiology of regional mechanical dysfunction in the border zone (BZ) region of left ventricular aneurysm was studied in an ovine model using magnetic resonance imaging tissue-tagging and regional deformation analysis. METHODS: Transmural infarcts were created in adult Dorsett sheep (n = 8) by ligation of the distal homonymous coronary artery and were allowed to mature into left ventricular aneurysms for 8 to 12 weeks. Animals were imaged subsequently using double oblique magnetic resonance imaging with radiofrequency tissue tagging. Short axis slices were selected for analysis that included predominantly the septal component of the aneurysm as well as adjacent BZ regions in the anterior and posterior ventricular walls. Dark grid patterns of magnetic presaturations were placed on the myocardium and tracked as they deformed during the diastolic, isovolumic systolic, and systolic ejection phases of the cardiac cycle. Regional ventricular wall strains were calculated in BZ regions and regions remote from the aneurysm and compared with strains measured in corresponding regions from normal control sheep (n = 6). RESULTS: Diastolic midwall circumferential strains (fiber extensions) were relatively preserved, but abnormal circumferential lengthening strains were observed in the BZ regions during isovolumic systole. Peak circumferential strains ranged from 0.04 to 0.07 in the BZ regions but averaged -0.05 in the normal hearts (p = 0.002 for the anterior BZ and p = 0.001 for the posterior BZ). Midwall end-systolic fiber strains were depressed in the anterior BZ (-0.03 to -0.09 for the BZ versus -0.11 for the normal heart, p < 0.0001) but not in the posterior BZ (p = 0.19). CONCLUSIONS: Our data support the theory that the stretching of BZ fibers during isovolumic systole contributed to a reduction in fiber shortening during systolic ejection and thus reduced the overall contribution of these fibers to forward ventricular output.

Animals↗
PubMed1995

An inverse approach to determining myocardial material properties.

Passive myocardial material properties have been measured previously by subjecting test samples of myocardium to in vitro load-deformation analysis or, in the intact heart, by pressure-volume relationships. A new method for determining passive material properties, described in this paper, couples a p-version finite element model of the heart, a nonlinear optimization algorithm and a dense set of transmural measured strains that could be obtained in the intact heart by magnetic resonance imaging (MRI) radiofrequency tissue tagging. Unknown material parameters for a nonlinear, nonhomogeneous material law are determined by solving an inverse boundary value problem. An objective function relating the least-squares difference of model-predicted and measured strains is minimized with respect to the unknown material parameters using a novel optimization algorithm that utilizes forward finite element solutions to calculate derivatives of model-predicted strains with respect to the material parameters. Test cases incorporating several salient features of the inverse material identification problem for the heart are formulated to test the performance of the inverse algorithm in typical experimental conditions. Known true material parameters can be determined to within a small tolerance and random noise is shown not to affect the stability of the inverse solution appreciably. On the basis of these validation experiments, we conclude that the inverse material identification problem for the heart can be extended to solve for unknown material parameters that describe in vivo myocardial material behavior.

Algorithms↗
PubMed1995

Pulmonary transplantation.

OBJECTIVE: More than 2700 lung transplants have been performed since the initial clinical success in 1983. The evolution in the techniques of lung transplantation and patient management and the effects on results are reviewed. SUMMARY BACKGROUND DATA: Improvements in donor management, lung preservation, operative techniques, immunosuppression management, infection prophylaxis and treatment, rejection surveillance, and long-term follow-up have occurred in the decade following the first clinically successful lung transplant. A wider spectrum of diseases and patients treated with lung transplant have accentuated the shortage of suitable lung donors. The organ shortage has led to the use of marginal donors and a limited experience using living, related donors. METHODS: Changes in techniques and patient selection and management are reviewed and controversial issues and problems are highlighted. RESULTS: One-year survival of greater than 90% for single-lung transplant recipients and greater than 85% for bilateral lung transplant recipients have been achieved. Complications caused by airway complications has been reduced greatly. Obliterative bronchiolitis develops in 20% to 50% of long-term survivors and is the leading cause of morbidity and mortality after the first year after transplant. CONCLUSIONS: Lung transplantation has evolved into an effective therapy for a wide variety of causes of end-stage lung disease. Wider applicability requires solutions to the problems of donor shortage and development of obliterative bronchiolitis.

Humans↗
PubMed1994

Biopsy-induced tricuspid regurgitation after cardiac transplantation.

Transvenous endomyocardial biopsy is now well-established as the gold standard for evaluation of possible rejection episodes after cardiac transplantation. From 1985 to August 1992, 1990 patients have undergone 193 cardiac transplantations at Barnes Hospital. One hundred eighty-three patients survived their initial hospitalization and serve as the study group. Their records were reviewed for the purposes of identifying those with tricuspid regurgitation as a complication of right ventricular endomyocardial biopsy. These patients have undergone a total of 2,960 biopsies for an average of 16.2 biopsies per patient. Over a mean follow-up period of 4.22 years, all patients have been evaluated with standard two-dimensional echocardiograms. Mild to moderate tricuspid regurgitation was very common, but was thought to be biopsy-induced only if severe and accompanied by flail components of the tricuspid valve. Twelve patients were identified with this entity at our institution. Of these, 5 had no symptoms and were receiving no diuretics, 3 had mild symptoms consisting of lower extremity edema and continued to receive diuretics, 2 had moderate symptoms, and 2 had right heart failure and anasarca refractory to medical therapy. Both of the severely affected patients subsequently required tricuspid valve replacement. We conclude that the tricuspid valve apparatus is at significant risk of injury during endomyocardial biopsy, that most patients will be minimally symptomatic due to tricuspid regurgitation when this injury occurs, and that when the injury is accompanied by severe symptoms, the likelihood of improvement with medical therapy is small.

Actuarial Analysis↗