Influence of Left Ventricular Function on the "Aortic Regurgitation Index" Proposed for the Hemodynamic Assessment of Postprocedural Aortic Regurgitation.

The aortic regurgitation (AR) index, proposed as an objective indicator of postprocedural AR, decreases in proportion to AR severity, besides reportedly providing additional prognostic information. Meanwhile, left ventricular (LV) function has also been considered an essential prognostic factor. This study aimed to clarify whether LV function affected the AR index using cardiac catheterization data.A retrospective study was performed in patients whose LV function was evaluated using a micromanometer-tipped catheter. Patients with grade 2 or higher AR were excluded to explore non-AR factors affecting the AR index value. The AR index was calculated as a ratio of the gradient between the aortic diastolic blood pressure (DBP) and the LV end-diastolic pressure (EDP) to the aortic systolic blood pressure (SBP): AR Index = [ (DBP - LVEDP) / SBP] × 100.A total of 64 patients [age, 62 (interquartile range: 48-70) years; LV ejection fraction, 19% (16%-26%) ] were examined. AR index values ranged from 18.3 to 68.6. Despite having no AR, two patients displayed an AR index < 25, indicating significant AR. Multiple-regression analysis revealed that LV diastolic stiffness (ß = -0.750, P < 0.001), LV max dP/dt (ß = -0.296, P = 0.006), and heart rate (ß = 0.284, P = 0.011) were independent determinants of the AR index value.Patients with impaired LV diastolic function and preserved systolic function had low AR index values. The additional prognostic information of the AR index may be related to LV diastolic function.

Aortic Regurgitation in Acute Type-A Aortic Dissection: A Clinical Classification for the Perioperative Echocardiographer in the Era of the Functional Aortic Annulus.

The functional aortic annulus offers a clinical approach for the perioperative echocardiographer to classify the mechanisms of aortic regurgitation in acute type-A dissection. Comprehensive examination of the functional aortic annulus in this setting using transesophageal echocardiography can guide surgical therapy for the aortic root by considering the following important aspects: severity and mechanism of aortic regurgitation, extent of root dissection, and the pattern of coronary artery involvement. The final choice of surgical therapy also should take into account factors, such as patient presentation and surgical experience, to limit mortality and morbidity from this challenging acute aortic syndrome. This review explores these concepts in detail within the framework of the functional aortic annulus, detailed anatomic considerations, and the latest literature.

Aortic valve repair.

PURPOSE OF REVIEW: Recently, there has been a renewed interest with regard to surgical strategies for aortic valve preservation in the presence of isolated valve disease or concomitant aortic root disease, despite concerns having been raised about the mid/long-term durability of such repair techniques for the aortic valve. The aim of the present review is to analyze the currently available evidence about aortic valve repair strategies, for either bicuspid or tricuspid valves. RECENT FINDINGS: An improved understanding of the surgical anatomy and functional analysis of the aortic valve and root has allowed a systematic classification for the mechanisms of aortic valve insufficiency. Similarly, the use of dedicated instruments and devices has led to improved outcomes in terms of not only long-term survival but also freedom from reoperation. SUMMARY: Aortic valve repair, either as a stand-alone procedure or especially in combination with surgery of the root, is a well-tolerated and effective procedure with excellent outcomes at mid/long term. Recent efforts allowed the refinement of surgical techniques to develop a systematic approach to aortic valve repair, which implies a thorough understanding of the surgical anatomy, the functional causes of disease, and the available repair techniques along with their potential limitations. A specialized team including dedicated surgeons and cardiologists appears to be crucial to achieve durable and satisfactory outcomes following aortic valve repair.

Two-year outcomes after transcatheter or surgical aortic-valve replacement.

BACKGROUND: The Placement of Aortic Transcatheter Valves (PARTNER) trial showed that among high-risk patients with aortic stenosis, the 1-year survival rates are similar with transcatheter aortic-valve replacement (TAVR) and surgical replacement. However, longer-term follow-up is necessary to determine whether TAVR has prolonged benefits. METHODS: At 25 centers, we randomly assigned 699 high-risk patients with severe aortic stenosis to undergo either surgical aortic-valve replacement or TAVR. All patients were followed for at least 2 years, with assessment of clinical outcomes and echocardiographic evaluation. RESULTS: The rates of death from any cause were similar in the TAVR and surgery groups (hazard ratio with TAVR, 0.90; 95% confidence interval [CI], 0.71 to 1.15; P=0.41) and at 2 years (Kaplan-Meier analysis) were 33.9% in the TAVR group and 35.0% in the surgery group (P=0.78). The frequency of all strokes during follow-up did not differ significantly between the two groups (hazard ratio, 1.22; 95% CI, 0.67 to 2.23; P=0.52). At 30 days, strokes were more frequent with TAVR than with surgical replacement (4.6% vs. 2.4%, P=0.12); subsequently, there were 8 additional strokes in the TAVR group and 12 in the surgery group. Improvement in valve areas was similar with TAVR and surgical replacement and was maintained for 2 years. Paravalvular regurgitation was more frequent after TAVR (P<0.001), and even mild paravalvular regurgitation was associated with increased late mortality (P<0.001). CONCLUSIONS: A 2-year follow-up of patients in the PARTNER trial supports TAVR as an alternative to surgery in high-risk patients. The two treatments were similar with respect to mortality, reduction in symptoms, and improved valve hemodynamics, but paravalvular regurgitation was more frequent after TAVR and was associated with increased late mortality. (Funded by Edwards Lifesciences; ClinicalTrials.gov number, NCT00530894.).

European Association of Echocardiography recommendations for the assessment of valvular regurgitation. Part 1: aortic and pulmonary regurgitation (native valve disease).

Valvular regurgitation represents an important cause of cardiovascular morbidity and mortality. Echocardiography has become the primary non-invasive imaging method for the evaluation of valvular regurgitation. The echocardiographic assessment of valvular regurgitation should integrate quantification of the regurgitation, assessment of the valve anatomy, and function as well as the consequences of valvular disease on cardiac chambers. In clinical practice, the management of patients with valvular regurgitation thus largely integrates the results of echocardiography. It is crucial to provide standards that aim at establishing a baseline list of measurements to be performed when assessing regurgitation.

Transesophageal echocardiographic evaluation during aortic valve repair surgery.

For patients with aortic valve (AV) disease, the classic treatment has been AV replacement and this remains true for aortic stenosis. In contrast, repair of isolated aortic insufficiency (AI), with or without aortic root pathology, is emerging as a feasible and attractive option to replacement. The AV is one of the elements of the aortic root. As such, AI can develop if one or more elements of the aortic root are diseased. Intraoperative transesophageal echocardiographic evaluation permits analysis of the mechanisms of aortic regurgitation as well as differentiation between repairable and unrepairable AV pathology. Immediate postrepair transesophageal echocardiography provides important information about the quality and durability of repair and identifies variables associated with recurrent AI.

Advances in aortic valve repair: focus on functional approach, clinical outcomes, and central role of echocardiography.

The surgical classification of aortic regurgitation (AR) is based on cusp mobility. Based on this classification, there are 3 classes of AR: type I is defined as normal cusp mobility, type II is defined as excessive cusp mobility, and type III is defined as restricted cusp mobility. Patients often have multiple coexisting mechanisms. Because aortic valve (AV) repair is safe, effective, and durable, it likely will become a mainstream surgical option for the management of significant AR, even in the setting of a bicuspid valve. Intraoperative transesophageal echocardiography has a central role at all stages in AV repair. Before cardiopulmonary bypass, it can accurately diagnose the mechanism of AR to guide operative strategy for successful repair. After separation from cardiopulmonary bypass, it can comprehensively evaluate the AV repair, including the likelihood that the repair will be durable in the long-term. Important echocardiographic predictors of a durable AV repair include the absence of AR, cusp coaptation above the annular plane, a coaptation length >4 mm, and an effective cusp height >8 mm. The clinical applicability of AV repair continues to expand and likely will evolve into a mainstream surgical therapy for AR, including minimally invasive techniques.

A lesional classification to standardize surgical management of aortic insufficiency towards valve repair.

OBJECTIVE: Aortic valve repair is an alternative to valve replacement for treatment of chronic aortic insufficiency (AI). In order to standardize surgical management, we suggest a classification based on echocardiographic and operative analysis of valvular lesions. METHODS: Classification was based on the retrospective analysis of chronic AI mechanisms of 781 adults operated on electively between 1997 and 2003. RESULTS: AI was isolated (406 patients (52%)), associated with supra-coronary aneurysm (97 cases (12.4%)), or with aortic root aneurysm (278 patients (35.6%)). Etiologies of valvular or aortic lesions were respectively rheumatic, dystrophic and atheromatous in 17%, 73.6% and 9.4% of cases. Lesional classification is based on the analysis of chronic AI mechanisms defining type I with central jet (354 cases, 45.3%) and type II with eccentric jet (54.7%). Type Ia is defined as isolated dilation of sino-tubular junction (47 supra-coronary aneurysms), and type Ib as dilation of both sino-tubular junction and aortic annular base (233 root aneurysms, 74 isolated AI). The type II associates dilation of sino-tubular junction and annular base to a valvular lesion: IIa cusp prolapse (95 aneurysms, 200 isolated AI); IIb cusp retraction (132 rheumatic AI), IIc cusp tear (endocarditis, traumatic). CONCLUSION: A lesional classification aims to standardize the surgical management of aortic valve repair: type Ia, by supra-coronary graft; type Ib, by subvalvular aortic annuloplasty associated with the aortic root replacement with a remodelling technique (root aneurysm) or double sub- and supravalvular annuloplasty (isolated AI). For chronic AI type II, aortic annuloplasty associated a remodelling technique or double sub- and supravalvular annuloplasty is combined with the treatment of the cusp lesion (cusp resuspension, cusp reconstruction with autologous pericardium).

Functional classification of aortic regurgitation using cardiac computed tomography: comparison with surgical inspection.

In patients with aortic regurgitation (AR), a precise preoperative assessment of aortic valve (AV) pathology is important if AV repair or sparing operation is an alternative option. The aim of this study was to assess the diagnostic accuracy of computed tomography (CT) for evaluating the AR mechanism compared with surgical inspection. 59 patients with AR who underwent AV surgery and preoperative cardiac CT were evaluated. AR mechanism was classified into type 1 (aortic dilatation or cusp perforation), type 2 (prolapsed cusp) and type 3 (cusp retraction). Agreement between CT and surgical inspection was obtained. Correlation between aortic regurgitant orifice (ARO) and imaging parameters were evaluated. On surgical inspection, type 1 AR was noted in 22 patients, type 2 in 16 and type 3 in 21. Agreement regarding the AR mechanism on CT was excellent (intra-class correlation coefficient, 0.81). At the patient level, the Cohen's κ value for CT findings with surgical inspection was of 0.89. At the cusp level, moderate agreement was noted between CT and surgical inspection. In the per-cusp analysis, CT had a sensitivity of 72.6%, specificity of 85.1%, positive predictive value of 73.8% and negative predictive value of 84.3% for the detection of aortic cusp abnormality. The diameter, perimeter and area of aortic annulus had moderate correlation with ARO (r = 0.54-0.66, P < 0.001). CT-derived classification of AR mechanism showed excellent agreement with surgical inspection.

Valvular Heart Disease in Adults: Etiologies, Classification, and Diagnosis.

The prevalence of valvular heart disease (VHD) in the United States was estimated to be approximately 2.5% in the 1990s. The prevalence currently is thought to be increasing because of more accurate diagnostic methods and aging of the population. Mitral regurgitation (MR) is the most common valve defect, followed by aortic stenosis (AS) and aortic regurgitation (AR). Degenerative disease is the most common etiology of MR, AS, and AR, though these forms of VHD also can be caused by congenital valve defects, systemic inflammatory diseases, endocarditis, and many other conditions. Mitral stenosis, most often caused by rheumatic fever, is uncommon in the United States. When VHD is suspected, transthoracic echocardiography should be obtained first. Other tests, including transesophageal echocardiography, computed tomography scan, magnetic resonance imaging study, and cardiac catheterization, are used in special situations to obtain more detailed diagnostic information. Guidelines for VHD management recommend interval monitoring with echocardiography. The exact interval recommended depends on the severity of the valve dysfunction and whether the patient is symptomatic. Monitoring of asymptomatic patients is important because early intervention, when valve function worsens or symptoms develop, is associated with better outcomes.

Parameters indicative of persistence of valvular pathology at initial diagnosis in acute rheumatic carditis: the role of albumin and CD19 expression.

OBJECTIVE: The aim of this study is to define the predictors of chronic carditis in patients with acute rheumatic carditis (ARC). METHODS: Patients diagnosed with ARC between May 2010 and May 2011 were included in the study. Echocardiography, electrocardiography, lymphocyte subset analysis, acute phase reactants, plasma albumin levels, and antistreptolysin-O (ASO) tests were performed at initial presentation. The echocardiographic assessments were repeated at the sixth month of follow-up. The patients were divided into two groups according to persistence of valvular pathology at 6th month as Group 1 and Group 2, and all clinical and laboratory parameters at admission were compared between two groups of valvular involvement. RESULTS: During the one-year study period, 22 patients had valvular disease. Seventeen (77.2%) patients showed regression in valvular pathology. An initial mild regurgitation disappeared in eight patients (36.3%). Among seven (31.8%) patients with moderate regurgitation initially, the regurgitation disappeared in three, and four patients improved to mild regurgitation. Two patients with a severe regurgitation initially improved to moderate regurgitation (9.1%). In five (22.8%) patients, the grade of regurgitation [moderate regurgitation in one (4.6%), and severe regurgitation in 4 (18.2%)] remained unchanged. The albumin level was significantly lower at diagnosis in Group 2 (2.6±0.48g/dL). Lymphocyte subset analysis showed a significant decrease in the CD8 percentage and a significant increase in CD19 percentage at diagnosis in Group 2 compared to Group 1. CONCLUSION: The blood albumin level and the percentage of CD8 and CD19 (+) lymphocytes at diagnosis may help to predict chronic valvular disease risk in patients with acute rheumatic carditis.

Ejection fraction response to supine exercise in asymptomatic aortic regurgitation: relation to simultaneous hemodynamic measurements.

The change in ejection fraction during exercise is frequently employed as a measure of left ventricular functional reserve in patients with aortic regurgitation. However, little information is available about its relation to invasive measurements of cardiac performance. Therefore, simultaneous hemodynamic measurements and supine exercise blood pool scintigraphy were performed in 14 patients with severe, asymptomatic or minimally symptomatic aortic regurgitation associated with cardiomegaly but preserved left ventricular function at rest. Their hemodynamic measurements at rest were normal and their exercise capacity was excellent. When the patients were categorized into those patients whose ejection fraction increased or did not decrease by more than 0.05 (Group 1) and those whose ejection fraction decreased by more than 0.05 (Group 2), important differences were apparent. Echocardiographic, radionuclide and hemodynamic measurements at rest in the two patient groups were similar, but Group 1 exhibited a greater increase in cardiac index during supine exercise (2.8 +/- 0.4 to 10.0 +/- 1.8 versus 2.7 +/- 0.5 to 6.9 +/- 1.0 liters/min per m2; p less than 0.005) and a lesser increase in pulmonary capillary wedge pressure (13 +/- 4 to 19 +/- 7 versus 12 +/- 4 to 31 +/- 8 mm Hg; p less than 0.01). The severity of regurgitation decreased during exercise in all patients, but end-diastolic volume decreased and end-systolic volume decreased or was unchanged in Group 1, whereas end-diastolic volume was unchanged and end-systolic volume increased in Group 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Optimizing timing of surgical correction in patients with severe aortic regurgitation: role of symptoms.

OBJECTIVES: We sought to determine the independent effect of preoperative symptoms on survival after surgical correction of aortic regurgitation (AR). BACKGROUND: Aortic valve replacement for severe AR is recommended after New York Heart Association functional class III or IV symptoms develop. However, whether severe preoperative symptoms have a negative influence on postoperative survival remains controversial. METHODS: Preoperative characteristics and postoperative survival in 161 patients with functional class I or II symptoms (group 1) were compared with those in 128 patients with class III or IV symptoms (group 2) undergoing surgical repair of severe isolated AR between 1980 and 1989. RESULTS: Compared with group 1, group 2 patients were older (p < 0.0001), were more often female (p = 0.001) and more often had a history of hypertension (p = 0.001), diabetes mellitus (p = 0.029) or myocardial infarction (p = 0.005) and were more likely to require coronary artery bypass graft surgery (p < 0.0001). The operative mortality rate was higher in group 2 (7.8%) than in group 1 (1.2%, p = 0.005), and the 10-year postoperative survival rate was worse (45% +/- 5% [group 2] vs. 78% +/- 4% [group 1], p < 0.0001). Compared with age- and gender-matched control subjects, long-term postoperative survival was similar to that expected in group 1 (p = 0.14) but significantly worse in group 2 (p < 0.0001). On multivariate analysis, functional class III or IV symptoms were significant independent predictors of operative mortality (adjusted odds ratio 5.5, p = 0.036) and worse long-term postoperative survival (adjusted hazard ratio 1.81, p = 0.0091). CONCLUSIONS: In the setting of severe AR, preoperative functional class III or IV symptoms are independent risk factors for excess immediate and long-term postoperative mortality. The presence of class II symptoms should be a strong incentive to consider immediate surgical correction of severe AR.

Evaluation of aortic insufficiency by Doppler color flow mapping.

The color Doppler echocardiographic studies and aortic angiograms of all patients who had these procedures performed within 2 weeks of each other between October 1984 and August 1985 were reviewed to determine whether any parameters of the regurgitant jet visualized by color Doppler study predicted the severity of aortic insufficiency as assessed by angiographic grading. Patients with an aortic valve prosthesis were excluded. Twenty-nine patients had aortic insufficiency and had adequate color Doppler studies for analysis. The mean time between color Doppler examination and angiography was 2.3 days (range 0 to 12). The maximal length and area of the regurgitant jet were poorly predictive of the angiographic grade of aortic insufficiency. The short-axis area of the regurgitant jet from the parasternal short-axis view at the level of the high left ventricular outflow tract relative to the short-axis area of the left ventricular outflow tract at the same location best predicted angiographic grade, correctly classifying 23 of 24 patients. However, the jet could be seen from this view in only 24 of the 29 patients. The height of the regurgitant jet relative to left ventricular outflow tract height measured from the parasternal long-axis view just beneath the aortic valve correctly classified 23 of the 29 patients. Mitral stenosis or valve prosthesis, which was present in 10 patients, did not interfere with the diagnosis or quantitation of aortic insufficiency by these methods.(ABSTRACT TRUNCATED AT 250 WORDS)

Valvular heart disease in patients taking pergolide.

OBJECTIVE: To Investigate the frequency of valvular heart disease in patients taking pergolide. PATIENTS AND METHODS: The medical records of patients seen at the Mayo Clinic in Jacksonville, Fla, between 1998 and 2003 were searched electronically for the word pergolide and the presence of a 2-dimensional echocardiogram. Patients who had not taken pergolide before undergoing echocardlography served as the control group. Echocardiograms were reviewed for the presence of valvular regurgitation. The frequency of valvular disease in patients taking pergolide was calculated and compared with controls. Associations with dosage and years of treatment also were examined. RESULTS: Fifty-five patients made up the pergolide group, and 63 served as controls. When looking at aortic regurgitation (AR) of any degree, 45% of patients in the pergolide group had AR, compared with 21% of controls (P = .006). The frequency of moderate to severe valvular regurgitation in the pergolide group was 11% (95% confidence interval [CI], 4%-22%), 13% (95% CI, 5%-24%), and 13% (95% CI, 5%-24%) for the tricuspid, mitral, and aortic valves, respectively. No statistical difference was identified in the frequency of moderate to severe valvular regurgitation (mitral, tricuspid, or aortic) when compared with controls. There was marginal evidence of an association between a higher daily dosage of pergolide and moderate to severe AR (P = .05). CONCLUSION: The frequency of AR appears to be Increased in patients taking pergolide. Our study suggests that if a cause-effect relationship exists between pergolide and valvular heart disease, it likely occurs at a low but clinically important Incidence and may be associated with dosage.

Structure and function of the tricuspid and bicuspid regurgitant aortic valve: an echocardiographic study.

OBJECTIVES: The emerging new treatment options for aortic valve disease call for more sophisticated diagnostics. We aimed to describe the echocardiographic pathophysiology and characteristics of the purely regurgitant aortic valve in detail. METHODS: Twenty-nine men, with chronic aortic regurgitation without concomitant heart disease referred for aortic valve intervention, underwent 2D transoesophageal echocardiographic (TEE) examination prior to surgery according to a previously published matrix. Measurements of the aortic valve apparatus in long and short axis view were made in systole and diastole and analysed off-line. The aortic valves were grouped as tricuspid (TAV) or bicuspid (BAV), and classified by regurgitation mechanism. RESULTS: Twenty-four examinations were eligible for analysis of which 13 presented TAV and 11 BAV. The regurgitation mechanism was classified as dilatation of the aorta in 6 cases, as prolapse in 11 cases and as poor cusp tissue quality or quantity in 7 cases. The ventriculo-aortic junction (VAJ) and valve opening were closely related (TAV r = 0.5, BAV r = 0.73) but no correlation was found between the VAJ and the maximal sinus diameter (maxSiD) or the sinotubular junction (STJ). However, the STJ and maxSiD were significantly related (TAV vs BAV: systole r = 0.9, r = 0.8; diastole r = 0.9, r = 0.7), forming an entity. The conjoined BAV cusps were shorter than the anterior cusps when closed (P = 0.002); the inter-commissural distances of the cusps in the BAV group were significantly different (P = 0.001 resp. 0.03) in both systole and diastole. CONCLUSIONS: The VAJ was independent of other aortic dimensions and should thereby be considered as a separate entity with influence on valve opening. The detailed 2D TEE measurements of this study add further important information to our knowledge about the function and echocardiographic anatomy of the pathological aortic valve and root either as a stand-alone examination or as a benchmark and complement to 3D echocardiography. This may have an impact on decisions regarding repairability of the native aortic valve.

Aortic cusp sizers to establish the functional classification of aortic insufficiency: algorithm and midterm outcome of operative repair.

OBJECTIVES: Wider adoption of aortic valve repair procedures is held up by the difficulty in recognizing the exact alterations that are responsible for aortic valve insufficiency. New aortic cusp sizers were developed to assist in aortic valve assessment in the operating theatre. Our objectives were to examine the efficacy of the aortic cusp sizers in establishing the functional classification of aortic valve insufficiency, and to report the midterm outcome in a group of patients who had undergone aortic valve repair guided by this device. METHODS: A prospective clinical study was performed involving 33 consecutive patients (18 males, age range: 8-74 years) with severe aortic valve insufficiency (mean severity: 3.4 ± 0.5). The aortic cusp sizers were used as a template to identify existing cusp and root alterations. Consequently, the functional classification of aortic insufficiency was determined, and the appropriate techniques of aortic valve repair were implemented. RESULTS: Aortic valve repair was successful in all patients. Procedures performed were 37 functional aortic annulus corrections, 9 cusp free-edge plications, 2 cusp repairs with autologous pericardium, 9 replacements of the ascending aorta and 2 reimplantation procedures. At a mean follow-up time of 18.3 ± 13.7 months, 1 patient underwent aortic valve replacement for recurrent aortic valve regurgitation, while aortic valve function remained stable in 32 patients, with aortic insufficiency <1+ in 27 (84.4%) patients and 1-1.5 in 5 (15.6%) patients, and no significant gradients across the aortic valves. CONCLUSIONS: The aortic cusp sizers are valuable in establishing the functional classification of aortic insufficiency, and can guide implementation of aortic valve repair techniques successfully. This approach is analogous to that accredited for the success and wide adoption of mitral valve repair techniques, and is likely to assist in increasing the percentage of aortic valves that are repaired when compared with current practice.

Correlation of continuous-wave Doppler assessment of chronic aortic regurgitation with hemodynamics and angiography.

Fifteen patients with chronic aortic regurgitation (AR) were studied by cardiac catheterization and continuous-wave (CW) Doppler echocardiography. The slope of the AR CW Doppler signal was higher in patients with severe AR (5.7 +/- 2.1 m/s2) than in those with moderate (2.5 +/- 1.3 m/s2) or mild (1.8 +/- 0.7 m/s2) AR (p less than 0.05). The slopes in patients with mild (less than or equal to 18 mm Hg), moderate (19 to 24 mm Hg) and severe (greater than 24 mm Hg) elevation of left ventricular end-diastolic pressure were significantly different (1.9 +/- 0.6, 3.3 +/- 1.2 and 7.1 +/- 0.4 m/s2, respectively, p less than 0.05). Patients with severe AR had shorter pressure half-times than those with mild AR (283 +/- 141 vs 820 +/- 393 ms, p less than 0.05). There was a significant correlation between the slope and left ventricular end-diastolic pressure (r = 0.80, p less than 0.001) and a weaker inverse correlation between pressure half-time and left ventricular end-diastolic pressure (r = -0.59, p less than 0.05). The end-diastolic pressure gradient estimated from CW Doppler using a simplified Bernoulli equation correlated poorly with the catheter measured gradient (r = 0.59, p less than 0.02). The slope of the CW Doppler signal is a better predictor of severity than pressure half-time and is affected by left ventricular end-diastolic pressure in addition to angiographic severity of AR.

Cardiovascular investigations and fuzzy sets theory.

Examining the circumstances that often lead modern, mechanistic cardiovascular research into areas devoid of practical significance, we suggest that our approaches, instead of our technology, are inadequate. A method for processing information, built on the concept of "fuzzy sets," is described as a potential way out of this dilemma. This system deserves application to clinical problems, perhaps together with more classic quantitative methods, because of its practical consequences and the conceptual revitalization it may bring.