Valve orifice area alone is an insufficient index of aortic stenosis severity: effects of the proximal and distal geometry on transaortic energy loss.

BACKGROUND AND AIMS OF THE STUDY: Standard measures of hemodynamic severity of aortic valve stenosis vary widely among patients with and without clinical symptoms. Our hypothesis is that valve orifice area alone is not the sole determinant of adverse clinical outcome. Stenotic orifice area ratio is ratio of the cross-sectional stenotic orifice area to the down-stream, ascending aorta cross-sectional area. Determination of workload together with aortic valve orifice area ratio might improve risk stratification among asymptomatic patients with critical aortic stenosis. Accordingly, application of both parameters together might be useful in guiding management decisions in this condition. METHODS: In this study the dependency of transaortic fluid mechanical energy transfer (one component of left ventricular workload) on aortic valve orifice area is shown using modeling and experimental techniques. RESULTS: For a stroke volume of 62 ml at a heart rate of 60 beats/min, the piston work (analogous to left ventricular work) increased by 17% as the stenotic orifice area ratio decreased from 0.60 to 0.25, by 35% as the ratio fell from 0.25 to 0.20, and by 73% as the ratio fell from 0.20 to 0.10. CONCLUSIONS: As predicted by the fundamental fluid mechanical theory, simulated left ventricular work and energy loss in aortic stenosis are influenced not only by the effective stenotic valve orifice area, but also by the geometry of the inflow and outflow conduits, proximal and distal to the valve. These findings might explain clinically observed discrepancies between valve orifice area and the onset of the classical symptoms of severe aortic stenosis that reflect the left ventricular workload. Consideration of the left ventricular work in addition to the effective valve orifice area should enhance clinical evaluation, prognostication and risk stratification among patients with severe aortic stenosis.

Improved risk stratification in unstable angina: identification of patients at low risk for in-hospital cardiac events by admission echocardiography.

BACKGROUND: Current protocols for risk stratification of patients with acute chest pain syndromes rely on clinical parameters and are oriented toward identification of patients at high risk for adverse cardiac events; however, this paradigm for risk stratification does not adequately address the observation that adverse cardiac events are relatively uncommon in this population. In an era of cost containment, consideration also should be given to identification of patients at low risk for adverse cardiac events, who may be safely discharged without expensive inpatient hospitalization. HYPOTHESIS: The purpose of this study was to develop echocardiographic predictors that identify unstable angina patients at low risk for adverse cardiac events and that discriminate between low- and high-risk patients. METHODS: The predictive accuracy of retrospectively determined echocardiographic predictors were compared in a population-based sample of 66 consecutive unstable angina patients undergoing echocardiography within 24 h of admission. RESULTS: Echocardiographic predictors of adverse events included wall motion score index > or = 0.2, ejection fraction < or = 40%, and mitral regurgitation severity > 2. One or more echocardiographic predictors of adverse events were present in 32 patients (48%). A composite echocardiographic predictor of adverse events was specific, had a high positive predictive value for the identification of high-risk patients, and discriminated between unstable angina patients at high and low risk for adverse cardiac events. CONCLUSION: Echocardiographic predictors of adverse events are specific and discriminate between unstable angina patients at high and low risk for adverse cardiac events.

Assessment of small-diameter aortic mechanical prostheses: physiological relevance of the Doppler gradient, utility of flow augmentation, and limitations of orifice area estimation.

BACKGROUND: Noninvasive assessment of functionally stenotic small-diameter aortic mechanical prostheses is complicated by theoretical constraints relating to the hemodynamic relevance of Doppler-derived transprosthetic gradients. To establish the utility of Doppler echocardiography for evaluation of these valves, 20-mm Medtronic Hall and 19-mm St Jude prostheses were studied in vitro and in vivo. METHODS AND RESULTS: Relations between the orifice transprosthetic gradient (equivalent to Doppler), the downstream gradient in the zone of recovered pressure (equivalent to catheter), and fluid mechanical energy losses were examined in vitro. Pressure-flow relations across the 2 prostheses were evaluated by Doppler echocardiography in vivo. For both types of prosthesis in vitro, the orifice was higher than the downstream gradient (P<0.001), and fluid mechanical energy losses were as strongly correlated with orifice as with downstream pressure gradients (r2=0.99 for both). Orifice and downstream gradients were higher and fluid mechanical energy losses were larger for the St Jude than the Medtronic Hall valve (all P<0.001). Whereas estimated effective orifice areas for the 2 valves in vivo were not significantly different, model-independent dynamic analysis of pressure-flow relations revealed higher gradients for the St Jude than the Medtronic Hall valve at a given flow rate (P<0.05). CONCLUSIONS: Even in the presence of significant pressure recovery, the Doppler-derived gradient across small-diameter aortic mechanical prostheses does have hemodynamic relevance insofar as it reflects myocardial energy expenditure. Small differences in function between stenotic aortic mechanical prostheses, undetectable by conventional orifice area estimations, can be identified by dynamic Doppler echocardiographic analysis of pressure-flow relations.

Echocardiography for hemodynamic assessment of patients with advanced heart failure and potential heart transplant recipients.

OBJECTIVES: This study sought to assess the accuracy of Doppler echocardiographic techniques for the determination of right heart catheterization hemodynamic variables in patients with advanced heart failure and in potential heart transplant recipients. BACKGROUND: Doppler echocardiographic techniques permit the noninvasive acquisition of hemodynamic variables traditionally used for the assessment of patients with advanced heart failure and potential heart transplant candidates. However, the accuracy of these techniques has not been sufficiently well documented for clinical application in individual patients. METHODS: Echocardiographic data required for estimation of mean right atrial, pulmonary artery and mean left atrial pressures and cardiac output were obtained. Right heart catheterization was performed immediately after Doppler echocardiographic data were acquired, before any intervention that might have altered the subject's hemodynamic status. RESULTS: A complete Doppler echocardiographic hemodynamic data set was acquired in 21 (84%) of 25 subjects. For all variables, invasive and noninvasive hemodynamic values were highly correlated (p < 0.001), with minimal bias and narrow 95% confidence limits. An algorithm constructed from the noninvasive hemodynamic variable values identified all patients with adverse pulmonary vascular hemodynamic variables (i.e., transpulmonary gradient > or = 12 mm Hg, pulmonary vascular resistance > or = 3 Wood units or pulmonary vascular resistance index > or = 6 Wood units x m2). This algorithm identified 12 (71%) of 19 patients for whom right heart catheterization was unnecessary. CONCLUSIONS: Doppler echocardiographic estimates of hemodynamic variables in patients with advanced heart failure are accurate and reproducible. This noninvasive methodology may assist with monitoring and optimization of medical therapy in patients with advanced heart failure and may obviate the need for routine right heart catheterization in potential heart transplant candidates.

Comparison of estimates of right atrial pressure by physical examination and echocardiography in patients with congestive heart failure and reasons for discrepancies.

Clinical estimates of right atrial pressure from the jugular venous pulse were accurate when right atrial pressure was normal, but systematically underestimated elevated right atrial pressures. Because the increased distance from the mid-right atrium to the sternal angle is not accounted for, apparently normal right atrial pressure estimates by this technique do not reliably exclude elevated right atrial pressure in patients with congestive heart failure.

Left ventricular outflow tract obstruction as a cause for hypotension and symptoms during dobutamine stress echocardiography.

BACKGROUND: Hypotension has been found to occur in more than one-third of patients during DBSE. Unlike traditional treadmill exercise stress testing, hypotension does not appear to be associated with significant coronary artery disease or left ventricular (LV) dysfunction. Several ischemic and nonischemic mechanisms such as dynamic LV intracavitary obstruction have been implicated in the pathogenesis of hypotension and the induction of symptoms during DBSE. HYPOTHESIS: The purpose of this study was the prospective evaluation of patients referred for dobutamine stress echocardiography (DBSE) to determine (1) the frequency of hypotension during DBSE, (2) the underlying mechanisms responsible for the induction of hypotension, and (3) to describe the cardiac chamber sizes and mass of patients in whom hypotension occurs. METHODS: Seventy-eight consecutive patients were studied during DBSE. Pulsed and continuous-wave Doppler echocardiography were performed at baseline and at each dobutamine infusion stage. Maximum velocities were recorded. Cardiac output was determined noninvasively at each stage in patients who developed an outflow tract gradient. Echocardiography was used to characterize LV dimensions and mass. RESULTS: During dobutamine infusion, 14 of 78 (18%) patients developed a left ventricular outflow tract (LVOT) velocity > or = 2.5 m/s. Pulsed Doppler echocardiography verified that the maximal velocity originated in the LVOT. Of the patients who developed an LVOT gradient, 57% had a concomitant hypotensive response to dobutamine compared with 33% of patients without a gradient (not significant). Four of nine patients had a simultaneous fall in cardiac output. Patients who developed an LVOT gradient had smaller LV dimensions and increased wall thicknesses compared with those who did not develop a gradient. CONCLUSIONS: Dobutamine stress echocardiography precipitates LVOT obstruction in certain patients. The development of a gradient corresponded with a fall in blood pressure and a decline in cardiac output in nearly half of the patients. These findings suggest that stress-induced LVOT obstruction may be responsible in part for the hemodynamic changes and symptoms experienced by these patients during exercise.

Antigenic specificity of lymphocytes isolated from valvular specimens of rheumatic fever patients.

T cell lines were established from both valvular specimens and peripheral blood lymphocytes from seven patients with well documented rheumatic heart disease. These cell lines were stimulated with either PHA or streptococcal antigens. Proliferation assays revealed that both valvular and peripheral blood T cell lines reacted to cell wall (CW) and cell membrane (CM) antigens obtained from rheumatic fever associated group A streptococci and not to nephritogenic strains. None of the cell lines reacted to M protein, myosin or other mammalian cytoskeletal proteins. The unique reactivity of rheumatic fever T cell lines only to cellular structures obtained from rheumatogenic strains suggests that these lines react to epitopes specific for antigens obtained from these strains.

Physiological relevance of T-tube model parameters with emphasis on arterial compliances.

The T-tube model of systemic arterial circulation was examined with respect to the physiological relevance of model parameters. root aortic pressure [Pao(t)] and flow [Qao(t)] and descending aortic flow [Qb(t)] were measured in anesthetized, open-chest dogs under control conditions, during inflation of a balloon positioned in the left external iliac artery (n = 5), and during infusion of vasoactive drugs nitroprusside (NTP, n = 4) and phenylephrine (PHL, n = 5). With Pao(t) as the input, the model accurately predicted both Qao(t) and Qb(t) under all conditions (r2 > 0.96). The balloon inflation data established the ability of the model to discriminate between proximal and distal arterial mechanical properties. Furthermore, proximal properties (i.e., tube characteristic impedances and transit times) were independent of distal properties such as terminal compliances and resistances (or equivalently, wave reflections). The effects of NTP and PHL were pharmacologically consistent and served to further validate this model. NTP primarily affected distal (load) properties, whereas PHL altered both load and tube parameters. Physiological interpretation of model parameters, particularly compliance, is also discussed. The ability of the model to correctly discriminate between proximal and distal arterial properties is relevant because these properties may affect cardiovascular function differently.

Perirectal abscess.

STUDY OBJECTIVE: To review clinical features of perirectal abscesses and to determine appropriate management. DESIGN: Retrospective analysis of medical records. SETTING: Urban teaching hospital. PARTICIPANTS: Ninety-two patients with the discharge diagnosis of perirectal abscess over a 4-year period. RESULTS: Perirectal pain was the most common presenting symptom, being present in 98.9% of cases. External perianal and digital rectal examination identified an abscess in 94.6% of patients. A variety of aerobic and anaerobic bacteria from skin, bowel, and, rarely, vagina were identified as causative agents, with mixed infections common. The major complications of perirectal abscesses included formation of extensive abscesses and urine retention. Abscess resolution occurred in all patients after adequate drainage. Antibiotics appeared to be useful only as adjunct therapy. CONCLUSION: Effective management of perirectal abscess involves early, adequate drainage, with antibiotics in an adjunct role.

Differential effects of chronic oral antihypertensive therapies on systemic arterial circulation and ventricular energetics in African-American patients.

BACKGROUND: A comprehensive evaluation of arterial load characteristics and left ventricular energetics in systemic hypertension has been limited by the need for invasive techniques to access instantaneous aortic pressure and flow. As a consequence of this methodological limitation, no data exist on the effects of long-term antihypertensive therapy on global arterial impedance properties and indexes of myocardial oxygen consumption (MVO2). Using recently validated noninvasive techniques, we compared in hypertensive patients the effects of chronic oral treatment with ramipril, nifedipine, and atenolol on arterial impedance and mechanical power dissipation as well as indexes of MVO2. METHODS AND RESULTS: Sixteen African-American subjects with systemic hypertension were studied with a randomized, double-blind, crossover protocol. Instantaneous central aortic pressure and flow, from which arterial load characteristics can be derived, were estimated from calibrated subclavian pulse tracings (SPTs) and continuous-wave aortic Doppler velocity in conjunction with two-dimensional (2D) echocardiographic measurements of the aortic annulus, respectively. To derive ventricular wall stress and indexes of MVO2, left ventricular short- (M-mode) and long-axis (2D echo) images were acquired simultaneously with SPTs. Data were collected at the end of a 2-week washout period (predrug control) and after 6 weeks of treatment with each agent. Although all three agents reduced diastolic blood pressure to the same extent, different effects on mean and systolic pressures and vascular impedance properties were noted. Nifedipine reduced total peripheral resistance (TPR; 1744 +/- 398 versus 1290 +/- 215 dyne-s/cm5) and increased arterial compliance (ACL; 1.234 +/- 0.253 versus 1.776 +/- 0.415 mL/mm Hg). This improvement in arterial compliance was not entirely accounted for by the reduction in distending pressure. Ramipril also decreased TPR (1740 +/- 292 versus 1437 +/- 290 dyne-s/cm5) and increased ACL (1.214 +/- 0.190 versus 1.569 +/- 0.424 mL/mm Hg), but with this agent, the change in arterial compliance was explained solely on the basis of a reduction in distending pressure. Atenolol, in contrast, did not affect either TPR or ACL. In agreement with the compliance results, nifedipine and ramipril significantly lowered the first two harmonics of the impedance spectrum, but atenolol did not. None of these agents resulted in a significant change in characteristic impedance or in the relative amplitude of the reflected pressure wave. Total vascular mechanical power and percent of oscillatory power remained unaltered with all antihypertensive treatments. Only ramipril and nifedipine reduced the integral of both meridional and circumferential systolic wall stresses, indicating that MVO2 per beat was reduced with these agents. Stress-time index, a measure of MVO2 per unit time, decreased significantly with ramipril but not with nifedipine because of an increase in heart rate noted in 10 of 16 patients (mean increase, 10 beats per minute). Thus, a reduction in MVO2 coupled with unchanged total vascular mechanical power suggests improved efficiency of ventriculoarterial coupling with ramipril and with nifedipine in the subset of patients in whom heart rate remained unchanged. In contrast, there was no evidence of a reduction in wall stress, stress integral, or stress-time index with atenolol. CONCLUSIONS: The noninvasive methodology used in this study constitutes a new tool for serial and simultaneous evaluation of arterial hemodynamics and left ventricular energetics in systemic hypertension. In this study, we demonstrate the differential effects of chronic antihypertensive therapies on systemic arterial circulation and indexes of MVO2 in African-American subjects. Consideration of drug-induced differential responses of arterial load and indexes of MVO2 with each drug may provide a more physiological approach to the treatment of systemic hypertension in indivi

Effects of left ventricular pressure on sonicated albumin microbubbles: evaluation using an isolated rabbit heart model.

OBJECTIVES: We used an isolated, crystalloid-perfused rabbit heart model to test the hypothesis that the phasic changes in left ventricular contrast are due to bubble compression and decompression during systole and diastole, respectively. BACKGROUND: Contrast enhancement of the left ventricular cavity has been shown to decrease during ventricular systole. This phenomenon has been attributed to pressure-induced microbubble destruction. Such destruction, if confirmed, would severely confound the quantitative interpretation of contrast echocardiographic data. METHODS: A fixed volume of contrast solution (5% human albumin and Albunex, approximately 400:1 ratio) was introduced into a latex balloon placed within the left ventricular cavity of an isolated paced rabbit heart preparation (n = 12). Instantaneous left ventricular pressure was measured using a high fidelity microtip catheter and digitized on-line. The beating heart was placed in a water tank, and ultrasound images were obtained using a 7.5-MHz transducer and were recorded and digitized off-line at 12 frames/s. Simultaneously, the pacing signal was used for gated on-line acquisition of end-diastolic frames. A simple theoretic model based on surface tension physical principles was used to predict changes in bubble size and, consequently, the reflection intensity in response to the measured changes in left ventricular pressure. RESULTS: We found that under peak left ventricular systolic pressures ranging from 89 to 155 mm Hg, 1) end-diastolic videointensity decreased by 8 +/- 6% (mean +/- SD) over 25 consecutive heart beats; and 2) intracyclic variations in measured videointensity were in close agreement with the theoretic calculations: 80.1 +/- 2.9% versus 80.2 +/- 4.6% of diastolic videointensity at systole. CONCLUSIONS: The major cause of systolic decrease in contrast enhancement is periodic bubble compression (as opposed to bubble destruction) induced by high systolic pressures. The minor progressive decrease in end-diastolic videointensity reflects the degree of instability of Albunex microbubbles under left ventricular pressures. However, the clinical impact of these destructive effects is likely to be only minor because of the rapid transit of microbubbles through the left heart chambers and myocardial microcirculation.

Measurement of regional elastic properties of the human aorta. A new application of transesophageal echocardiography with automated border detection and calibrated subclavian pulse tracings.

BACKGROUND: Evaluation of regional aortic elastic properties in humans has been hampered by the need for invasive techniques to access instantaneous aortic pressure, wall thickness, and cross-sectional area or diameter. In this study, a new noninvasive method is presented for quantification of regional aortic elastic properties. METHODS AND RESULTS: Twenty-five patients were studied during transesophageal echocardiographic procedures. Measurements of instantaneous aortic cross-sectional area were obtained with an automated border detection algorithm applied to short-axis transesophageal two-dimensional echocardiographic images of the proximal descending thoracic aorta. Instantaneous aortic wall thickness was derived from combined two-dimensional targeted M-mode end-diastolic wall thickness and instantaneous aortic area measurements. Instantaneous aortic pressures were estimated from calibrated subclavian pulse tracings recorded simultaneously. Data were digitized to generate aortic area-pressure loops. Regional aortic mechanical properties were quantified in terms of compliance per unit length (C is the slope of the area-pressure regression), aortic midwall radius (Rm), and incremental elastic modulus of the aortic wall (Einc). To assess the independent effect of age, Rm and Einc values were compared at a common level of aortic midwall stress (0.666 x 10(6) dynes/cm2). Mean values (+/- SD) for C, Rm, and Einc were 0.01 +/- 0.004 cm2/mm Hg, 1.14 +/- 0.17 cm, and 7.059 +/- 4.091 x 10(6) dynes/cm2, respectively. An inverse linear correlation was found between aortic compliance per unit length and age (r = -.68, P < .0007). Incremental elastic modulus was related to age (r = +.80, P < .00003) in a nonlinear fashion such that it increased sharply after the age of 60 years. Finally, midwall radius was less tightly correlated with age (r = +.45, P < .05). Values for C, Rm, and Einc as well as the age dependency of these properties are similar to those reported previously when invasive techniques were used. CONCLUSIONS: This methodology constitutes a new tool to improve the clinical evaluation of regional aortic elastic properties in multiple disease states.

Paradoxic improvement in regional wall motion during high-dose dobutamine stress echocardiography. A marker for hibernating myocardium?

Dobutamine stress echocardiography detects myocardial ischemia by inducing regional left ventricular systolic dysfunction. Augmentation of wall motion in hypokinetic segments has also been noted with low-dose dobutamine, suggesting myocardial viability. We report a case of regional ventricular improvement during high-dose dobutamine therapy, which may represent relief from myocardial hibernation or changes in regional loading conditions.

Noninvasive method for determination of arterial compliance using Doppler echocardiography and subclavian pulse tracings. Validation and clinical application of a physiological model of the circulation.

BACKGROUND: The Poiseuillian model of the arterial system currently applied in clinical physiology does not explain how arterial pressure is maintained during diastole after cessation of pulsatile aortic inflow. Arterial pressure-flow relations can be more accurately described by models that incorporate arterial viscoelastic properties such as arterial compliance. Continuous pressure and flow measurements are needed to evaluate these properties. Since the techniques used to date to acquire such data have been invasive, physiological models of the circulation that incorporate these properties have not been widely applied in the clinical setting. The purpose of this study was (1) to validate noninvasive methods for continuous measurement of central arterial pressure and flow and (2) to determine normal reference values for arterial compliance using physiological models of the circulation applied to the noninvasively acquired pressure and flow data. METHODS AND RESULTS: Simultaneously acquired invasive and noninvasive aortic pressures (30 patients), flows (8 patients), and arterial mechanical properties (8 patients) were compared. Pressure was measured by high-fidelity catheter aortic micromanometer (invasive) and calibrated subclavian pulse tracing (noninvasive). Aortic inflow was determined from thermodilution-calibrated electromagnetic flow velocity data (invasive) and echo-Doppler data (noninvasive). Arterial compliance was determined for two- and three-element windkessel models of the circulation using the area method and an iterative procedure, respectively. Once validated, the noninvasive methodology was used to determine normal compliance values for a reference population of 70 subjects (age range, 20 to 81 years) with normal 24-hour ambulatory blood pressures and without Doppler-echocardiographic evidence for structural heart disease. The limits of agreement between invasive and noninvasive pressure data, compared at 10% intervals during ejection and nonejection, were narrow over a wide range of pressures, with no significant differences between methods. Invasive and noninvasive instantaneous aortic inflow values differed slightly but significantly at the start of ejection (P < .05), but during the latter 90% of ejection, values for the two methods were similar, with narrow limits of agreement. Total vascular resistance and arterial compliance values derived from invasive and noninvasive data were similar. Arterial compliance values for the normal population using the two-element model (C2E) ranged from 0.74 to 2.44 cm3/mm Hg (mean, 1.57 +/- 0.38 cm3/mm Hg), with a beat-to-beat variability of 5.2 +/- 3.9%. C2E decreased with increasing age (r = -.73, P < .001) and tended to be higher in men (1.67 +/- 0.41 cm3/mm Hg) than in women (1.51 +/- 0.35 cm3/mm Hg, P = .07). Compliance values for the three-element model (C3E) were predictably smaller than for the two-element model (mean, 1.23 +/- 0.30; range, 0.59 to 2.16 cm3/mm Hg, P < .001 versus C2E) but correlated with C2E values (r = .81, P < .001) and were also inversely related to age (r = -.56, P < .001). Ridge regression and principal component analyses both showed the compliance value to be a composite function whose variation could be best predicted by consideration of simultaneous values for five major hemodynamic determinants: heart rate, mean flow, mean aortic pressure, minimal diastolic pressure, and end-systolic pressure. Multivariate analysis revealed age and sex to be independent predictors of compliance (P < .01 for both). There were no differences in compliance between black and white subjects. CONCLUSIONS: Noninvasive methods can be used to acquire the hemodynamic data necessary for clinical application of physiological models of the circulation that incorporate arterial viscoelastic properties such as arterial compliance. The strong inverse linear relation between model-based compliance estimates and age mandates incorporation of this demographic parameter in

The spectrum of severe rheumatic mitral valve disease in a developing country. Correlations among clinical presentation, surgical pathologic findings, and hemodynamic sequelae.

OBJECTIVE: To describe the demographic, pathologic, and hemodynamic profiles of patients with severe rheumatic mitral valve disease in a developing country and to assess their relation to uncontrolled rheumatic disease activity. DESIGN: Retrospective, cross-sectional, cohort study. SETTING: Tertiary medical center in Soweto, South Africa. PATIENTS: 714 of 737 consecutive black patients, 4 to 73 years old, with pure mitral regurgitation, pure mitral stenosis, or mixed mitral disease who had mitral valve surgery and in whom preoperative and surgical data were concordant. MEASUREMENTS: Valve lesions were evaluated on the basis of clinical, echocardiographic, hemodynamic, and surgical pathologic data. Active rheumatic carditis was diagnosed according to clinical evidence for concurrent acute rheumatic fever (Jones criteria), macroscopic appearances at surgery, and histologic findings. RESULTS: 219 patients had pure mitral regurgitation, 275 had pure mitral stenosis, and 220 had mixed lesions. Ongoing rheumatic activity was diagnosed in 106 patients with pure regurgitation (47%) and in only 5 patients with pure stenosis (2%). Pure regurgitation was the most common lesion in the first and second decades; the relative prevalence of pure stenosis increased with age. Purely regurgitant valves had pliable, unscarred leaflets (95%), dilated mitral annuli (95%), elongated chordae tendineae (92%), and anterior leaflet prolapse (81%). In contrast, purely stenotic valves had fused leaflet commissures (100%) and rigid leaflets (38%) but no evidence of prolapse. CONCLUSIONS: The spectrum of rheumatic mitral valve disease that is hemodynamically severe in developing countries differs from that currently reported in the United States. Severe, pure rheumatic mitral regurgitation is as prevalent as pure stenosis but has an entirely different time course, surgical anatomy, and relation to disease activity, suggesting a separate pathophysiologic mechanism.

Double-chambered left ventricle: submitral accessory valvular tissue causing inlet and outlet obstruction.

We report a patient with a large submitral ridge of muscular and fibrous tissue that divides the left ventricle into two distinct chambers causing inlet and outlet obstruction. Doppler echocardiography revealed obstruction to both filling and ejection. Echocardiography demonstrated that the obstruction was in series with the mitral apparatus. Surgery was done with resection of much of this ring of tissue. Subsequent studies revealed morphologic and hemodynamic improvement.