Photosynthetic microbial fuel cell with polybenzimidazole membrane: synergy between bacteria and algae for wastewater removal and biorefinery.

Here, we demonstrate a very efficient simultaneous approach of bioenergy generation from wastewater and added-value compounds production by using a photosynthetic microalgae microbial fuel cells (PMFC), based on polybenzimidazole (PBI) composite membrane as separator. The use of PBI was proved to be very promising, even more convenient than Nafion™ in terms of energy performances as well as cost and sustainability. This polymer is also easily autoclavable, so allowing a re-use of the separator with a consequent beneficial cost effect. Two PMFCs were investigated: 1) Pt electrocatalysed and 2) Pt-free. They were operated as microbial carbon capture (MCC) device under continuous illumination, by using a domestic wastewater as anolyte and Scenedesmus acutus strain in the catholyte. The Pt-based cell allowed to generate higher volumetric power density (∼400 mW m-3) after more than 100 operating days. This resulted in an improved wastewater treatment efficiency, determined in terms of normalised energy recovery (NER > 0.19 kWh kgCOD-1 in case of Pt). The CO2 fixation of the PMFC-grown microalgae leaded to a high accumulation of added-value products, namely pigments and fatty acids. A significant quantity of lutein was observed as well as a relevant amount of other valuable carotenoids, as violaxanthin, astaxanthin and cantaxanthin. The lipids were even excellently accumulated (49%dw). Their profile was mainly composed by fatty acids in the range C16-18, which are particularly indicated for the biofuel production. These results demonstrate the feasibility and the implemented sustainability of such PMFCs as a great potential technology for the wastewater treatment and the simultaneous production of valuable products.

Isolated ultrafiltration in moderate congestive heart failure.

OBJECTIVES: The aim of this study was to evaluate whether ultrafiltration is beneficial in patients with moderate congestive heart failure. BACKGROUND: Ultrafiltration is beneficial in patients with severe congestive heart failure. METHODS: We studied 36 patients in New York Heart Association functional classes II and III in stable clinical condition. Eighteen patients (group A) were randomly selected and underwent a single session of ultrafiltration (venovenous bypass, mean [+/- SEM] ultrafiltrate 1,880 +/- 174 ml, approximately 600 ml/h) and 18 (group B) served as control subjects. RESULTS: Two patients in group A and three in group B did not complete the 6-month follow-up study. In group A, soon after ultrafiltration there were significant reductions in right atrial pressure (from 8 +/- 1 to 3.4 +/- 0.7 mm Hg, pulmonary wedge pressure (from 18 +/- 2.5 to 10 +/- 1.9 mm Hg) and cardiac index (from 2.8 +/- 0.2 to 2.3 +/- 0.2 liters/min). During the follow-up period, lung function improved, extravascular lung water (X-ray score) decreased and peak oxygen consumption (ml/min per kg) increased significantly from 15.5 +/- 1 (day -1) to 17.6 +/- 0.9 (day 4), to 17.8 +/- 0.9 (day 30), to 18.9 +/- 1 (day 90) and to 19.1 +/- 1 (day 180). Oxygen consumption at anaerobic threshold (ml/min per kg) also increased significantly from 11.6 +/- 0.8 (day -1) to 13 +/- 0.7 (day 4), to 13.7 +/- 0.5 (day 30), to 15.5 +/- 0.8 (day 90) and to 15.2 +/- 0.8 (day 180). These changes were associated with increased ventilation, tidal volume and dead space/tidal volume ratio at peak exercise. The improvement in exercise performance was associated with a decrease in norepinephrine at rest, a downward shift of norepinephrine kinetics at submaximal exercise and an increase in norepinephrine during orthostatic tilt. None of these changes were recorded in group B. CONCLUSIONS: In patients with moderate congestive heart failure, ultrafiltration reduces the severity of the syndrome.

Medium-term effectiveness of L-thyroxine treatment in idiopathic dilated cardiomyopathy.

BACKGROUND: In dilated cardiomyopathy, short-term administration of L-thyroxine (100 micrograms/ day) improves cardiac and exercise performance without changing the heart's adrenergic sensitivity. The aim of this study was to test the medium-term (3 months) efficacy of L-thyroxine (10 patients) compared with placebo (10 patients) and to find out whether later effects are obtainable. METHODS: Echocardiographic parameters in the control state and during acute changes of left ventricular afterload, cardiopulmonary exercise test, and hemodynamic parameters, including cardiac beta 1 responses to dobutamine, were obtained before and at the end of treatment. RESULTS: Significant (P < 0.05) changes were observed only with the active drug. After L-thyroxine, patients did not show evidence of chemical hyperthyroidism, despite the increase in thyroxine and the reduction in thyroid-stimulating hormone plasma levels. Cardiac performance improved, as shown by the increase in the left ventricular ejection fraction and rightward shift of the slope of the relation left ventricular ejection fraction/end-systolic stress. Resting cardiac output increased, and the left ventricular diastolic dimensions and systemic vascular resistances decreased. The responses of cardiac output and heart rate to dobutamine infusion were also enhanced. Functional capacity markedly improved, together with an increase in peak exercise cardiac output. CONCLUSION: L-thyroxine does not lose its beneficial effects on cardiac and exercise performance on medium-term administration and does not induce adverse effects. In addition to the short-term study, the left ventricular diastolic dimensions were decreased. An upregulation of beta 1 receptors might explain the cardiac response to dobutamine.

Doppler assessment of left ventricular filling pattern in silent ischemia in patients with Prinzmetal's angina.

Spontaneous angina is an ideal condition in which to study left ventricular (LV) dysfunction induced by acute myocardial ischemia. In 6 patients with Prinzmetal's angina, LV diastolic function during 16 episodes of spontaneous angina was studied by simultaneous recordings of electrocardiographic (ECG), echocardiographic and hemodynamic parameters. In particular, pulsed Doppler echocardiography measured peak velocity of early (E) and late (A) transmitral flow and E/A ratio, as indexes of relative early versus late LV filling. During the ischemic attacks, the time sequence of pulsed Doppler echocardiographic and ECG changes showed 3 distinct phases: (1) "waxing phase: transmitral flow changes with minimal ECG modifications (E/A = 0.85 +/- 0.1); (2) "steady" phase: maximal ECG changes (E/A = 0.9 +/- 0.1); and (3) "waning" phase: regression of the ECG changes (E/A = 1.26 +/- 0.15). In each phase, E/A ratio showed a significant difference from the baseline value (E/A = 1.17 +/- 0.2) as a result of changes in E, suggesting that myocardial ischemia affects mainly the early phase of diastole. In the waxing phase, LV diastolic dysfunction preceded systolic abnormalities, as documented by a significant reduction of E/A ratio in the absence of alterations in LV ejection fraction, as well as in systemic arterial and pulmonary wedge pressures. Finally, all the recorded parameters were consistent with LV "contractile rebound" occurring in the waning phase and affecting both diastole and systole.

Usefulness of L-thyroxine to improve cardiac and exercise performance in idiopathic dilated cardiomyopathy.

The short-term effects of L-thyroxine (100 micrograms/day, 10 patients) and placebo (10 patients) on idiopathic dilated cardiomyopathy were compared. Before and at the end of the treatment, a hemodynamic study was performed in the control state and during dobutamine infusion. A cardiopulmonary exercise test was also performed with hemodynamic monitoring. An echocardiogram was recorded in the control state and during acute changes of left ventricular afterload. Plasma levels of triiodothyronine, thyroxine, thyroid-stimulating hormone and norepinephrine were measured. Placebo was ineffective. After administration of L-thyroxine all patients had normal thyroid function. The increase in left ventricular ejection fraction and the rightward shift of the slope of left ventricular ejection fraction/end-systolic stress relation (p < 0.05) indicated an improvement in the cardiac inotropic state. This proved to be independent of adrenergic influences by the unchanged beta 1 response to dobutamine. A decrease in resting systemic vascular resistances and an increase in cardiac output (p < 0.05) were also observed. Cardiopulmonary effort parameters improved (p < 0.05) without hemodynamic changes at peak exercise. It is concluded that L-thyroxine short-term administration improves cardiac and exercise performance in patients with chronic heart failure, without modifying the adrenergic support to the heart and the circulatory parameters at peak exercise.

Influences of aortic pressure gradient and ventricular septal thickness with systolic coronary flow in aortic valve stenosis.

This study evaluates flow patterns of the left anterior descending and circumflex coronary arteries by multiplane transesophageal echocardiography in 25 patients with aortic valve stenosis, and assesses the relation between coronary flow characteristics and anatomic and hemodynamic parameters.

Lung-heart interaction as a substrate for the improvement in exercise capacity after body fluid volume depletion in moderate congestive heart failure.

We investigated exercise capacity after fluid depletion in patients with moderate congestive heart failure (CHF). Twenty-one patients underwent ultrafiltration (mean volume +/- SEM: 1,770 +/- 135 ml). Echocardiography, tests of pulmonary function, and a cardiopulmonary exercise test with hemodynamic and esophageal pressure monitoring were performed before ultrafiltration and 3 months later. Tests without invasive measurements were repeated 4 and 30 days after ultrafiltration. Twenty-one control patients followed the same protocol but did not have ultrafiltration. Patients who underwent ultrafiltration and increased their oxygen consumption at peak exercise (peak VO2) by > 10% at the 3-month evaluation (group A1, n = 9) were separated from those who did not (group A2, n = 8); 3 patients did not complete the follow-up. Four days after the procedure, peak VO2 had risen from 17.3 +/- 0.8 to 19.3 +/- 0.9 ml/min/kg in group A1, and from 11.9 +/- 0.7 to 14.1 +/- 0.7 ml/min/kg in group A2 (p < 0.01). Plasma norepinephrine and pulmonary function were consistent with a greater severity of the syndrome in group A2. At 3 months in group A1, the relations of filling pressure to cardiac index of the right and left ventricles were shifted upward; the esophageal pressure swing (differences between end-expiratory and end-inspiratory pressure) for a given tidal volume was lower; the peak exercise dynamic lung compliance had increased from 0.10 +/- 0.05 to 0.14 +/- 0.03 L/mm Hg (p < 0.01). None of these changes were detected in group A2 and control patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Accessory thyroid tissue in the right ventricle.

In an asymptomatic 66-year-old woman presenting a systolic murmur in the pulmonic area, echocardiography evidenced a voluminous mass in the right ventricular outflow tract resembling a cardiac tumor. Histologic finding was that of aberrant normal thyroid. Although the occurrence of ectopic thyroid tissue in the heart is rare, it should be considered in the differential diagnosis whenever a mass is located at the level of the interventricular septum and encroaches on the right ventricular outflow tract. In these cases, a thyroid scintiscan may avoid an unnecessary surgical intervention.

Inspired gas relative humidity affects systemic to pulmonary bronchial blood flow in humans.

To our knowledge, the effects of humidity of inspired air on bronchial blood flow in humans are unknown. During total cardiopulmonary bypass, we measured systemic to pulmonary bronchial blood flow (Qbr[s-p]) which is the volume of blood accumulating into the left side of the heart in the absence of pulmonary and coronary flow. A cannula was introduced into the right upper pulmonary vein and advanced into the lowermost portion of the left side of the heart. From this cannula Qbr(s-p) was vented by gravity and measured. Inspired gas (10 L/min, endotracheal tube, 50 percent O2 + 50 percent N2O) relative humidity was less than 20 percent and greater than 85 percent in group A (n = 25) and in group B (n = 25), respectively. Mean (+/- SE) Qbr(s-p) was 40.7 +/- 0.06 ml/min or 1.32 +/- 0.12 ml/min (percent cardiac output) in group A and 21.7 +/- 1.8 ml/min or 0.68 +/- 0.06 ml/min in group B. These data indicate that under these conditions Qbr(s-p) is increased by dry gas lung inflation in humans.

Systemic to pulmonary bronchial blood flow in heart failure.

STUDY OBJECTIVE: The aim of this study was to measure systemic to pulmonary blood flow from bronchial circulation (Qbr[s-p]) in patients with heart failure. DESIGN: In the absence of pulmonary and coronary flows, Qbr(s-p) is the volume of blood accumulating in the left side of the heart; Qbr(s-p) was measured during total cardiopulmonary bypass for coronary artery surgery; bronchial blood was vented through a cannula introduced into the left side of the heart and its volume was measured. PATIENTS: Patients were subdivided according to the presence for more than 6 months (group 1, n = 6) or less than 2 months (group 2, n = 7), or the absence of heart failure (group 2, n = 15). MEASUREMENTS AND RESULTS: Qbr(s-p) was 89 +/- 18* mL/min, 27 +/- 3, 22 +/- 2, in groups 1, 2, and 3, respectively (* = p < 0.01 group 1 vs groups 2 and 3). During total cardiopulmonary bypass, pulmonary venous pressure approximates atmospheric pressure and no differences between groups were observed in systemic artery pressure, extracorporeal circulation pump flow, and airway pressure. Therefore, vascular resistance through the bronchial vessels draining into the pulmonary circulation is reduced in patients with heart failure for more than 6 months (group 1). CONCLUSIONS: During total cardiopulmonary bypass, Qbr(s-p) is increased in patients with chronic heart failure. Since with elevated pulmonary vascular pressure blood flow through Qbr(s-p) vessels is from the pulmonary to the systemic circulation, the lower resistance observed in group 1 suggests that bronchial vessels might contribute to reduced lung fluid overload in patients with chronic heart failure.

Intraoperative multiplane vs biplane transesophageal echocardiography for the assessment of cardiac surgery.

This study was undertaken to test whether multiplane transesophageal echocardiography (TEE) offers advantages in comparison with biplane TEE in the intraoperative monitoring during cardiac surgery. A diagnostic multiplane TEE was performed in 400 patients in the immediate preoperative and postoperative periods. We systematically acquired cardiac images from the gastric fundus, lower esophagus, and upper esophagus; complete views of the descending aorta were also recorded. Usefulness of the different views in providing essential additional clinical information compared with exclusive transverse (0 to 20 degrees) and longitudinal (70 to 110 degrees) planes of the biplane TTE was assessed assuming that with manipulation of a biplane probe, a 20 degrees are could be added to the conventional horizontal and vertical planes. A high success rate of each view was demonstrated; anatomy and pathologic condition were best visualized in oblique planes. The method proved to be particularly useful in the preoperative and postoperative phases of aortic dissection (27 cases), aortic (65 cases) and mitral (35 cases) valve replacement, mitral valve repair (38 cases), left ventricular aneurysmectomy (25 cases), bleeding from proximal suture of an aortic heterograft (2 cases), and positioning of left ventricular hemopump (2 cases). Additional regional wall motion abnormalities of the right (four cases) and left ventricle (six cases) not appreciated in 0 to 20 degrees or 70 to 110 degrees planes were detected. Multiplane TEE is a useful clinical tool during intraoperative monitoring of cardiac surgery. Most structures of the heart and great vessels lie on oblique planes, while other views are optimized with the aid of slight angle corrections. This method improves the evaluation of anatomy and pathologic condition of the heart and great vessels, of native and prosthetic valves, and of left and right ventricular function.

Exercise performance in patients with uncomplicated essential hypertension. Effects of nifedipine-induced acute blood pressure reduction.

In untreated patients with uncomplicated essential hypertension, exercise induces an abnormal increase in blood pressure; the influences of this increase on exercise were evaluated by a cardiopulmonary exercise test (CPX) performed in control conditions (step 1) and during acute blood pressure reduction (step 2). Patients were classified as (1) normotensive (resting diastolic blood pressure [BPd] less than 90 mm Hg; n = 14), (2) mildly hypertensive (BPd of 90 to 104 mm Hg; n = 9), and (3) moderately to severely hypertensive (BPd greater than or equal to 105 mm Hg; n = 16). For the three groups, peak mean blood pressure during exercise was 125 +/- 5 mm Hg (mean +/- SEM), 144 +/- 3 mm Hg (p less than 0.01 vs normotensive), and 161 +/- 4 mm Hg (p less than 0.01 vs normotensive and p less than 0.01 vs mild hypertension), respectively. Oxygen consumption (VO2) at peak exercise and at ventilatory anaerobic threshold was 26.1 +/- 1.1 and 17.2 +/- 0.5 ml/min/kg, 25.4 +/- 1.1 and 16.9 +/- 0.8 ml/min/kg, and 26.4 +/- 1.3 and 17.5 +/- 1.2 ml/min/kg in normotensive subjects, those with mild hypertension, and those with moderate to severe hypertension, respectively. Fourteen normotensive subjects, six with mild hypertension, and nine with moderate to severe hypertension participated to step 2 (nifedipine vs placebo, double-blind crossover). Nifedipine reduced blood pressure at rest and at peak exercise in those with hypertension. Peak exercise VO2 was unaffected by nifedipine in both normotensive subjects and those with hypertension. With nifedipine, ventilatory anaerobic threshold occurred earlier and at a lower VO2 in mild and in moderate to severe hypertension (delta VO2 = -1.9 and -2.4 ml/min/kg, respectively). These findings might be due to nifedipine-induced redistribution of blood flow during exercise and might be the reason for the complaint of weakness after blood pressure reduction in hypertensive subjects.

Modification of exercise performance by sharp reduction of blood pressure. A study in patients with uncomplicated hypertension.

We evaluated exercise performance in 14 patients with uncomplicated essential hypertension 1 h after the administration of a single dose of placebo, nifedipine (20 mg), captopril (50 mg), and propranolol (80 mg). Drugs were administered at the same time of day following a randomized, double-blind protocol. Mean resting blood pressure (+/- SE) was 135 +/- 3 mm Hg with placebo administration, 118 +/- 4 with captopril, 110 +/- 4 with nifedipine, and 115 +/- 5 with propranolol and increased with exercise to 163 +/- 4, 146 +/- 3, 136 +/- 4, 136 +/- 4, respectively. Oxygen consumption at peak exercise and at ventilatory anaerobic threshold (VAT) was 25.2 +/- 1.1 and 18.1 +/- 1.0 ml/min/kg with placebo. Only propranolol (-2.3 ml/min/kg) decreased peak exercise oxygen consumption. Oxygen consumption at VAT was reduced by nifedipine and propranolol but unaffected by captopril. The effects on exercise capacity of blood pressure reduction in hypertensive patients are dependent on the drug utilized and are not related to the amount of blood pressure reduction. The lowered oxygen consumption at VAT observed with nifedipine and propranolol, and not with captopril, might be due to an excessive downward shift of the muscle perfusion pressure--oxygen consumption relationship which might take place during exercise.

Systemic to pulmonary bronchial blood flow in mitral stenosis.

We measured systemic to pulmonary bronchial blood flow [Qbr(s-p)] during total cardiopulmonary bypass in 15 patients with mitral stenosis and elevated pulmonary venous pressure (group A, mean pulmonary wedge pressure = 22.2 +/- 5.4 mm Hg, mean +/- SD) and in 15 patients with coronary artery diseases and normal pulmonary venous pressure (group B). Qbr(s-p) is the volume of blood accumulating in the left side of the heart in the absence of pulmonary and coronary flows. This blood was vented through a cannula introduced into the left atrium and measured. Qbr(s-p) was 76.3 +/- 13.9 ml/min (2.18 +/- 0.37 percent of extracorporeal circulation pump flow) and 22.3 +/- 2.1 (0.63 +/- 0.15) in group A and B, respectively (p less than 0.01). During total cardiopulmonary bypass, pulmonary venous pressure is approximately atmospheric pressure, and no differences in systemic blood pressure, extracorporeal circulation pump flow, and airways pressure were observed between group A and B. Therefore, vascular resistance through the bronchial vessels draining into the pulmonary circulation is reduced in patients with mitral stenosis and elevated pulmonary venous pressure.

Increase of alveolar pressure reduces systemic-to-pulmonary bronchial blood flow in humans.

We studied the effect of positive alveolar pressure (PA) on systemic to pulmonary bronchial blood flow, Q?? in humans. The Q?? was measured during total cardiopulmonary bypass as the volume of blood accumulating in the left heart. This blood was vented by gravity from the left heart via a cannula introduced in the right upper pulmonary vein and advanced to the lowest portion of the left heart. In group A (n = 10) the Qbr(s-p) was measured for 25 to 95 min with constant PA (4.0 +/- 0.2 cm H2O, mean +/- SE). In group B (n = 10) Qbr(s-p) was measured for 20 min with PA = 4.1 +/- 0.2 cm H2O and for a further 20 min with PA = 14.1 +/- 0.4 cm H2O. The Qbr(s-p) ranged between 0.32 and 2.76 percent of cardiac output (pump flow) and remained constant with time (group A). The increase of PA from 4.1 +/- 0.2 to 14.1 +/- 0.4 cm H2O reduced Qbr(s-p) by approximately 40 percent (p less than 0.01, group B). We conclude that positive PA reduces Qbr(s-p) during total cardiopulmonary bypass. Therefore, we advise using low PA during assisted ventilation to preserve bronchial blood flow.

A new formula for echo-Doppler estimation of right ventricular systolic pressure.

The Doppler formulas currently used for right ventricular systolic pressure (RVSP) evaluation include right ventricular-right atrial (RV-RA) gradient and RA pressure. The former is expressed by the velocity of the trans-tricuspid regurgitant flow; the latter is generally assumed and is different from one formula to another. In 110 patients with cardiac disease with normal or elevated pulmonary pressure, we tested a new echo-Doppler formula for the evaluation of RVSP based on the estimation of RA pressure by means of the inferior vena cava collapsibility index (IVCCI) and compared this method with two traditional formulas (methods A and B) and with cardiac catheterization values. Patients were classified into three groups on the basis of IVCCI (group 1 > 45%, group 2 between 35% and 45%, and group 3 < 35%). RVSP was evaluated by method A (RV-RA gradient + 10), method B (RV-RA gradient x 1.1 + 14), and our new method, method C, which assigns 6, 9, and 16 mmHg to RA pressure in the presence of normal (> 45%), moderately reduced (between 35% and 45%), or markedly reduced (< 35%) IVCCI, respectively. IVCCI correctly identified RA pressure in the three groups (group 1, 6.8 mmHg; group 2, 10.8 mm Hg; and group 3, 13.1 mmHg); a high correlation existed between Doppler-derived and invasively determined RV-RA gradient (r = 0.99). Method C improved noninvasive estimation of RVSP in groups 1 and 3 compared with the other methods; in group 2, Doppler estimation of RVSP by methods A and C were comparable, whereas method B significantly overestimated the actual values.(ABSTRACT TRUNCATED AT 250 WORDS)

Coronary flow and left ventricular diastolic function in aortic regurgitation.

BACKGROUND: An abnormal coronary perfusion pressure is probably the major determinant of altered myocardial perfusion in aortic regurgitation; ventricular hypertrophy and diastolic function may also be involved. This study was undertaken to investigate the respective roles of these two variables. METHODS: Using multiplane transesophageal echocardiography, we evaluated the coronary Doppler flow velocity in the proximal left anterior descending coronary artery in 15 patients with aortic regurgitation before and immediately after valve replacement. The ratios of diastolic:systolic velocity integral and early:late diastolic velocity integral were correlated against coronary perfusion pressure, pulmonary wedge pressure and Doppler echocardiographic indices of left ventricular diastolic function. Patients were compared with 10 subjects without valvular diseases. RESULTS: Aortic regurgitation was associated with a reduction of the coronary diastolic:systolic velocity integral ratio and increment in the early:late diastolic velocity integral ratio. The latter correlated positively with early:late diastolic ratio of mitral flow velocity, pulmonary wedge pressure and left ventricular mass index. Soon after valve replacement, a decrease in pulmonary wedge pressure and a rise in coronary perfusion pressure were seen. Both the echo-Doppler parameters related to diastolic function and the systodiastolic distribution of coronary flow returned to normal. This indicates that diastolic dysfunction rather than left ventricular mass may be related to a disordered myocardial perfusion. CONCLUSIONS: In aortic regurgitation, a relationship exists between diastolic ventricular function and coronary flow phasic distribution. Valve replacement improves the former and normalizes the latter. Echo-Doppler parameters of diastolic dysfunction identify patients with worse coronary perfusion and might represent an additional criterion in the preoperative evaluation of patients with aortic regurgitation.

Cardiac tamponade produced by a loculated pericardial hematoma simulating a right atrial mass.

We report a case of cardiac tamponade due to thrombosis of a loculated pericardial effusion which occurred after open heart surgery. The loculated hematoma was highly echogenic and mimicked a right atrial mass. Cross-sectional echocardiography, in association with color Doppler flow imaging, was extremely useful in identifying this rare complication of cardiac surgery and, therefore, in determining the subsequent surgical approach.

Acute and chronic efficacy of felodipine in congestive heart failure.

In 13 patients with congestive heart failure we tested the acute hemodynamic effects of 5 vs. 10 mg felodipine tablets, in a double-blind, cross-over study. One hour after felodipine 5 mg, echocardiographic ejection fraction (%), cardiac index (thermodilution-ml/min/m2), and pulmonary wedge pressure (mm Hg) significantly changed (from 21 +/- 2 to 26 +/- 2, 2350 +/- 150 to 2790 +/- 160, 24 +/- 4 to 17 +/- 4) while they remained steady after felodipine 10 mg. The greatest stroke index increases were associated with felodipine 5 mg in 12 patients and 10 mg in 1 patient. Therefore we evaluated (open study) the long-term (2 months- 1 year) clinical and hemodynamic efficacy following the treatment with the acutely most effective dose (twice daily). After 2 months ejection fraction, cardiac index and pulmonary wedge pressure were respectively 24 +/- 2, 2550 +/- 150, and 18 +/- 4 (12 hours after the last drug administration, n = 11, P less than 0.02 from baseline). These parameters further increased one to two hours after the following administration of felodipine. Clinical improvement (reduction of 1 functional class, according to the New York Heart Association) was observed in 8/13 patients. These 8 patients participated to the one year follow-up. In 5 patients follow-up was interrupted because of acute cardiovascular events. However, before study interruption (5 patients) or ending (3 patients) clinical status did not worsen and ejection fraction remained higher than in the pretreatment period. Therefore, low dose felodipine might be used in the treatment of congestive heart failure.

Transesophageal echocardiography as predictor of mitral valve repair.

BACKGROUND AND AIM OF THE STUDY: Mitral valve repair has recently emerged as the treatment of choice in patients presenting with insufficiency due to valve prolapse. The study aims were to evaluate: (i) the clinical presentation in a consecutive series of patients with mitral valve prolapse undergoing surgical repair; (ii) the correlation between pre- and intraoperative echocardiographic features and surgical findings in these patients; and (iii) whether clinical and echocardiographic data may predict surgical outcome. METHODS: Between March 1997 and May 2000, 152 patients (110 men, 42 women; mean age 59+/-13 years) were recruited into the study. All patients had myxomatous mitral valve disease causing severe regurgitation and underwent systematic examination by transesophageal echocardiography (TEE) for clear delineation of the three scallops of the posterior leaflet and juxtaposed segments of the anterior leaflet. RESULTS: In 119 patients (78%) a flail valve was documented by TEE and confirmed on surgical inspection; an anterior leaflet chordal rupture was not visualized by TEE in one case. In 15 cases (10%) there was flail of the anterior leaflet, and in 105 cases (69%) flail of the posterior leaflet. A bileaflet complex prolapse without chordal rupture was found in 32 cases. On the basis of TEE evaluation, mitral valve replacement was performed electively in 10 patients (7%); the other 142 (93%) underwent mitral valve repair. Adequate repair was obtained in 93% of cases; residual mitral regurgitation (eight cases; grade 3+) and mitral stenosis (one case) were documented by intraoperative TEE, and nine patients (6%) underwent valve replacement. CONCLUSION: The majority of patients with myxomatous mitral valve prolapse and severe regurgitation undergoing valve repair have chordal rupture of the posterior mitral leaflet, a condition in which results of valve repair are excellent. TEE provides a powerful means to define the mechanisms of mitral regurgitation and to identify the suitability of patients for valvuloplasty.