Left atrial plication combined with mitral valve surgery in patients with a giant left atrium

The benefits of performing left atrial plication during mitral valve surgery for patients with a giant left atrium were evaluated by analyzing the short- and long-term surgical results and changes in the left atrial dimension (LAD) and respiratory function of 30 patients. Of the 30 patients, 2 (7%) died of multiple organ failure on postoperative days 26 and 117, but no other deaths occurred during the mean follow-up of 5.9±2.1 years. Valve thrombosis was observed in one patient and cerebral complications with no residual deficit were observed in two patients, with a 9-year event-free rate of 87±7%. The LAD decreased significantly from 69.0±8.5 mm to 53.7±9.1 mm (P<0.01) shortly after surgery, and this decrease was maintained even 5 years after surgery (53.3±11.4 mm). The cardiothoracic ratio decreased from 74.8±8.3% to 62.8±9.0% (P<0.01) and the vital capacity of the lungs increased from 71.1±18.0% to 82.9±22.2% (P<0.01). Thus, we conclude that performing left atrial plication during mitral valve surgery is safe and effective for patients with a giant left atrium.     

左心房折叠术在二尖瓣病变合并巨大左心房治疗中的应用

目的探讨左心房折叠术治疗二尖瓣病变合并巨大左心房的临床应用效果.方法回顾性分析23例收缩末期左心房内径为(129±37)mm (92～250 mm)、行左心房折叠术的二尖瓣手术患者的临床资料.22例选用人工机械瓣膜置换,1例为生物瓣置换,同期行左心房折叠术.术前心功能NYHA分级,Ⅲ级15例,Ⅳ级8例;术前心胸比为0.79±0.10.单纯二尖瓣置换术18例,其中行三尖瓣成形术10例;双瓣膜置换和三尖瓣成形术5例,其中二次手术2例, 术中行心房纤颤射频消融术2例.结果术后低心排出量综合征3例(13%),呼吸衰竭2例(9%).早期死亡3例(13%),其中2例为低心排出量综合征、1例为脑梗死.术后失访2例,术后1年意外死亡1例,平均随访(44±39)个月,17例生存患者心功能Ⅰ级14例、Ⅱ级3例;术后心胸比为0.68±0.11,较术前明显缩小(t=3.80,P=0.000).结论在瓣膜病手术的同时对巨大左心房症行左心房折叠术,可减少术后并发症,术后效果良好.     

Descriptive analysis of instantaneous left atrial volume—with special reference to left atrial function

Instantaneous left atrial volume was determined in five calves by electrical integration of left atrial differential flow (pulmonary vein flow less mitral valve flow). Volume changes were classified and compared to previously described mitral valve flow phases. With the onset of left ventricular isovolumic contraction, the left atrium began to fill. There was an initial rapid filling period, followed by a slower but steady increase in volume. With reversal of the atrioventricular gradient, there was an initial decrease in left atrial volume. This decrease then reached a plateau, during which the left atrium remained isovolumic. With atrial contraction there was a further decrease in left atrial volume. Left atrial function (reservoir, pump, or conduit) was evaluated using an algorithm to emphasize major changes. Reservoir function occurred mainly during ventricular systole, but was also seen during diastole. Pump function occurred only during ventricular diastole and could be further divided into passive and active components. The passive component contributed the majority of blood transfer from the atrium into the ventricle. Active atrial contraction provided only 13% of the stroke volume but under the conditions of normal sinus rhythms occurred at the most sensitive point of ventricular filling. Conduit function was seen during ventricular diastole, was inversely related to the reservoir and pump functions, and thus produced a rate of ventricular filling smoother than expected and permitted a maximal transfer of blood from the left atrium into the ventricle.     

The causes of prolonged postoperative respiratory care in mitral valve disease with a giant left atrium

Whether a giant left atrium in mitral valve disease itself prolongs postoperative respiratory care or does not is an important problem. We investigated it in 39 patients who underwent MVR without plication of the left atrium. A giant left atrium (GLA) was defined when CT-LA volume exceeded 300 ml by rapid sequential CT or left atrial diameter exceeded 60 mm by echocardiography. According to this criteria, the 39 patients were divided into two groups: 18 patients of GLA group and 21 of non-GLA group. Eight GLA (44%) and 11 non-GLA patients (52%) needed postoperative respiratory care with intratracheal intubation for more than 24 hours. Four GLA (22%) and 2 non-GLA patients (9.5%) needed reintubation. There was no significant difference between the two groups concerning the duration of postoperative respiratory care and the frequency of reintubation. The reintubated patients had three prominent preoperative clinical profiles, such as poor general condition, poor cardiac function and poor respiratory function. Consequently, it is concluded that in mitral valve disease with a GLA the prolongation of postoperative respiratory care is largely due to poor cardiac and respiratory function rather than to the compression to the bronchus by a GLA.     

Desflurane, sevoflurane, and isoflurane affect left atrial active and passive mechanical properties and impair left atrial-left ventricular coupling in vivo: analysis using pressure-volume relations

BACKGROUND: The effects of volatile anesthetics on left atrial function in vivo have not been described. The authors tested the hypothesis that desflurane, sevoflurane, and isoflurane alter left atrial mechanics evaluated with invasively derived pressure-volume relations. METHODS: Barbiturate-anesthetized dogs (n = 24) were instrumented for measurement of aortic, left atrial, and left ventricular pressures (micromanometers) and left atrial volume (orthogonal sonomicrometers). Left atrial contractility and chamber stiffness were assessed with end-systolic and end-reservoir pressure-volume relations, respectively, obtained from differentially loaded diagrams. Relaxation was determined from the slope of left atrial pressure decline after contraction. Stroke work and reservoir function were assessed by A and V loop areas, respectively. Left atrial-left ventricular coupling was determined by the ratio of left atrial contractility and left ventricular elastance. Dogs received 0.6, 0.9, and 1.2 minimum alveolar concentration desflurane, sevoflurane, or isoflurane in a random manner, and left atrial function was determined after 20-min equilibration at each dose. RESULTS: Desflurane, sevoflurane, and isoflurane decreased heart rate, mean arterial pressure, and maximal rate of increase of left ventricular pressure and increased left atrial end-diastolic, end-systolic, and maximum volumes. All three anesthetics caused dose-related reductions in left atrial contractility, relaxation, chamber stiffness, and stroke work. Administration of 0.6 and 0.9 minimum alveolar concentration desflurane, sevoflurane, and isoflurane increased V loop area. All three anesthetics decreased the ratio of stroke work to total left atrial pressure-volume diagram area, increased the ratio of conduit to reservoir volume, and reduced left atrial contractility-left ventricular elastance to equivalent degrees. CONCLUSIONS: The results indicate that desflurane, sevoflurane, and isoflurane depress left atrial contractility, delay relaxation, reduce chamber stiffness, preserve reservoir and conduit function, and impair left atrial-left ventricular coupling in vivo.     

Mitral valve annuloplasty: the effect of the type on left ventricular function

This study was undertaken to determine whether rigid-ring annuloplasty and flexible-ring annuloplasty have the same effect on left ventricular function in patients with chronic mitral regurgitation secondary to degenerative disease of the mitral valve. Twenty-five patients who underwent isolated mitral valve repair and required annuloplasty were randomized into two groups: rigid-ring and flexible-ring annuloplasty. Left ventricular function was assessed by echocardiography and radionuclide angiography on the day before operation and 2 to 3 months later. Preoperative left ventricular function was similar in the two groups of patients. Postoperatively, left ventricular end-diastolic diameter and volume decreased significantly in both groups. The left ventricular end-systolic diameter and volume decreased significantly only in patients with a flexible annuloplasty ring. Left ventricular systolic function as assessed by pressure-volume relationships was significantly better in patients with a flexible ring (p less than 0.02 by analysis of covariance), and left ventricular performance measured by stroke volume-end-diastolic volume relationships was also better in these patients (p less than 0.05 by analysis of covariance). These data indicate that patients with a flexible annuloplasty ring have better left ventricular systolic function than patients with a rigid annuloplasty ring 2 to 3 months after mitral valve reconstruction for chronic mitral regurgitation secondary to degenerative disease of the mitral valve.     

Effects of standard mitral valve replacement on left ventricular function

Recent studies have suggested that excision of the mitral valve apparatus during mitral valve replacement impairs left ventricular performance. However, functional measurements in humans have been difficult to obtain in a load-independent fashion. To investigate this concept, 12 patients (mean age, 65 +/- 8 years; mean New York Heart Association functional class, 3.3 +/- 0.7) with 4+ mitral regurgitation (n = 8) or mitral stenosis (valve area, 1.2 +/- 0.2 cm2) (n = 4) underwent prosthetic valve replacement using crystalloid cardioplegia. No patient required therapeutic inotropic support, every patient had at least the anterior mitral leaflet excised, and paced heart rate was maintained constant throughout. Left ventricular volume was measured with radionuclide angiocardiography, left ventricular pressure with a 3F micromanometer, and left ventricular wall volume with two-dimensional transesophageal echocardiography. Left ventricular preload was varied over a mean end-diastolic pressure range of 9 to 20 mm Hg and an end-diastolic volume range of 134 to 170 mL to generate four to five steady-state pressure-volume loops before and ten minutes after cardiopulmonary bypass. Left ventricular performance was estimated with the stroke work/end-diastolic volume relationship, which is insensitive to load. After bypass, no significant change (p greater than 0.1) was noted in wall volume for patients with mitral regurgitation or mitral stenosis (175 +/- 68 to 189 +/- 63 mL/m2 and 130 +/- 22 to 127 +/- 19 mL/m2, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)     

Poor correlation between pulmonary arterial wedge pressure and left ventricular end-diastolic volume after coronary artery bypass graft surgery

The authors studied 12 surgical patients in the intensive care unit post coronary artery bypass graft surgery and ten nonsurgical patients in the coronary care unit with chronic heart failure to determine the usefulness of the pulmonary arterial wedge pressure as an indicator of left ventricular preload. Left ventricular end diastolic volume was derived from concomitant determination of ejection fraction (gated blood pool scintigraphy) and stroke volume (determined from thermodilution cardiac output). In the nonsurgical patients, there was a significant correlation between changes in pulmonary arterial wedge pressure and left ventricular end-diastolic volume (P less than 0.05, r = 0.57). In the 12 patients studied during the first few hours after surgery, there was a poor correlation between changes in pulmonary wedge pressure (range = 4-32 mmHg) and left ventricular end-diastolic volume (range = 25-119 ml/m2), and a poor correlation between pulmonary arterial wedge pressures and stroke work index. In contrast, there was a good correlation between left ventricular end-diastolic volume and stroke work index. The poor correlation between the pulmonary arterial wedge pressure and left ventricular end-diastolic volume was not explained by changes in systemic or pulmonary vascular resistance. The altered ventricular pressure-volume relationship may reflect acute changes in ventricular compliance in the first few hours following coronary artery bypass graft surgery. While measurement of pulmonary arterial wedge pressure remains valuable in clinical management to avoid pulmonary edema, it cannot reliably be used as an index of left ventricular preload while attempting to optimize stroke volume in patients immediately following coronary artery bypass graft surgery.     

Left ventricular mechanics of ejecting, postischemic hearts during left ventricular circulatory assistance

We measured the effects of left ventricular circulatory assistance on ventricular mechanics of ejecting sheep hearts before and after global ischemia. Flows from left atrium to femoral artery ranged between 20 and 100 ml/kg/min during circulatory assistance. In preischemic, ejecting hearts increasing flow through the left ventricular assist device progressively decreased stroke volume, end-diastolic volume, and circumferential systolic wall stress, but only slightly decreased end-systolic volume. In postischemic, ejecting hearts left ventricular assistance progressively and substantially decreased both end-diastolic volume and end-systolic volume; at high flows, end-systolic volume returned to the normal range of preischemic hearts. High flows through the assist device also shifted end-systolic points of pressure-volume loops leftward and increased the stroke work/end-diastolic volume ratio in ejecting postischemic hearts; these observations raise the possibility that left ventricular circulatory assistance acutely improves myocardial contractility of postischemic hearts.     

Efficacy of left ventricular restoration with mitral valve surgery for endstage ischemic cardiomyopathy

Patients with ischemic cardiomyopathy (ICM) are at an extremely high risk of death and ischemic events. This study aims to evaluate the impact of left ventricular restoration (LVR) and mitral valve surgery on the cardiac and clinical functional status of the patients with ICM. Twenty-six patients (46-80 years, mean: 64 years) with severely dilated heart (left ventricular end-systolic volume index: LVESVI > or = 100 ml/m2) who had coronary artery bypass grafting (2.8+/-1.3), mitral valve surgery, and LVR were enrolled in this study. Left ventricular end-diastolic volume index and LVESVI significantly decreased (from 169+/-44 to 130+/-41 ml/m2, P=0.0005, from 120+/-33 to 89+/-43 ml/m2, P=0.0012). Left ventricular ejection fraction showed no change. MR showed significant improvement (from 2.7+/-0.6 to 1.0+/-0.4, P<0.0001) and NYHA functional class showed improvement (from 3.2+/-0.8 to 1.5+/-0.9, P<0.0001). A 5-year survival rate was 71.2%. In conclusion, this aggressive approach with LVR aiming to treat end-stage ICM by relief of ischemia, reduction of LV wall tension by decreasing LV volume and stopping mitral leak, is effective for LV volume reduction and improvement of clinical functional status.     

Cardiovascular effects of positive pressure ventilation in humans

Pulsus paradoxus is the pathological exaggeration of the normal transient decrease in arterial blood pressure that occurs during spontaneous inspiration. The transient increase in arterial pressure associated with positive pressure inspiration is termed reversed pulsus paradoxus (RPP). Cardiorespiratory interactions and the mechanism of these effects have been studied extensively in animals, and to a lesser extent, in humans. In this clinical investigation pulsus paradoxus and RPP were studied in 10 postoperative cardiac patients with invasive monitoring and mediastinal pressure catheters placed intraoperatively. From end-expiration to end-inspiration, RPP was accompanied by decreased transmural pressures in the right atrium, left atrium, and aorta. Left ventricular end-systolic volume measured by radionuclide studies diminished during a positive pressure inspiration, without a significant change in end-diastolic volume. These results are consistent with decreased left ventricular afterload as the major mechanism of RPP. During spontaneous breathing, inspiration was associated with converse effects, a fall in arterial pressure and an increase in transmural right atrial, left atrial, and aortic pressures from end-expiration to end-inspiration. End-systolic volume was significantly larger at end-expiration than end-inspiration, with no change in end-diastolic volume. These findings suggest that an increase in left ventricular afterload during inspiration is responsible for the observed pulsus paradoxus.     

Effects of the pericardium on left ventricular diastolic filling and systolic performance early after cardiac operations.

To determine whether closure of the pericardium after cardiac operations affects the filling characteristics and systolic performance of the left ventricle, we measured left ventricular volume, pressure, cardiac index, and stroke work index in 10 patients between 11 and 15 hours after cardiac operations, with the pericardium first closed and then open. At the time of operation, radiopaque tantalum markers were inserted in the left ventricular myocardium to outline the chamber in the 30-degree right anterior oblique projection, and the pericardium was closed by a continuous polypropylene suture exteriorized at both ends of the sternotomy. The patient was then transferred to the surgical intensive care unit, where left atrial pressure was measured via a fluid-filled catheter, left ventricular pressure with a micromanometer-tipped catheter, and myocardial oxygen consumption via a coronary sinus catheter. Left ventricular volume was measured by computer-aided analysis of fluoroscopic images (recorded at 30 frames per second) of the implanted myocardial markers. Left atrial pressure was maintained at target values of 10, 15, and 20 mm Hg by intravenous augmentation of blood volume. Left ventricular and left atrial pressures and volumes were measured with the pericardium closed; the pericardium was then opened by withdrawal of the pericardial suture. Radiopaque clips on the pericardial edges confirmed opening of the pericardium seconds after withdrawal of the suture. Repeated measurements of left ventricular pressures and volumes were then made at the target left atrial pressures with the pericardium open. End-diastolic volume index, peak positive time derivative of pressure, stroke work index, and cardiac index all increased significantly when the pericardium was opened (p < 0.001). Thus we found the following: (1) At physiologic pressures, the pericardium had a significant constraining effect on diastolic filling of the left ventricle, and (2) opening of the pericardium resulted in increased cardiac index and stroke work index. These increases may be attributed to the Frank-Starling response to increased left ventricular preload. The demonstrated improvement in left ventricular systolic performance should be considered when contemplating closure of the pericardium after cardiac operations, especially in patients with preoperative left ventricular dysfunction.     

Left Atrial Plication and Mitral Valve Replacement for Giant Left Atrium Accompanying Mitral Lesion

A bstract Between January 1982 and November 1992, 38 patients received simultaneous mitral valve replacement (MVR) and left atrial plication (LAP) because of giant left atrium accompanying mitral lesion. Their ages ranged from 33 to 70 years, and the mitral lesion was caused by rheumatic heart disease in all patients. MVR was performed with a St. Jude Medical prosthesis for all patients and the left atrial wall was plicated with running 3–0 Nespolene to reduce the width to 3 to 5 cm. Respiration requiring mechanical ventilation more than 48 hours after operation occurred in four patients (10.5%) and postoperative low cardiac output requiring a high dose of and dopamine HCI or intraaortic balloon pumping in nine patients (23.7%). The left atrial diameter measured by echocardiogram was a mean of 7.3 ± 1.0 cm before operation and 5.8 ± 1.0 cm postoperatively. The cardiothoracic ratio on the chest roentgenogram registered a preoperative mean of 73.3%± 9.8% and was 65.7%± 8.4% after operation. The pre- and postoperative values were significantly different (p < 0.01). The postoperative exercise level was a mean of 5.3 metabolic units for 24 patients and the postoperative New York Heart Association functional classification indicated Class I or II for 37 patients with no evidence of left atrial thrombus except in the case of one early death. LAP with MVR for patients with giant left atrium due to mitral lesion appeared to result in improvement in respiratory and circulatory functions.     

A novel technique for giant left atrium reduction.

We herein describe a safe and reproducible technique for left atrial volume reduction in patients with a giant left atrium. In a 56-year-old patient undergoing redo mitral valve replacement, the left atrium measured 18 x 20 x 17 cm occupying the middle-lower segment of the right hemithorax with compression of the adjacent organs. The left atrial volume was reduced by triangular resections of the atrial wall and the mitral valve was replaced using a mechanical prosthesis. The postoperative course was uneventful and the left atrial diameter was 11.2 cm at the latest control.     

Transesophageal echocardiography values for left ventricular end-diastolic area and pulmonary vein and mitral inflow Doppler velocities in patients undergoing coronary artery bypass graft surgery

OBJECTIVE: To determine left ventricular end-diastolic area (EDA) and pulmonary vein and mitral inflow Doppler velocities in patients undergoing coronary artery bypass graft (CABG) surgery using transesophageal echocardiography (TEE). To examine the effects of age, sex, and left ventricular function on these values. DESIGN: Prospective observational study; all measurements performed before cardiopulmonary bypass. SETTING: Tertiary referral teaching hospital. PARTICIPANTS: Eighty-six elective CABG surgery patients. INTERVENTIONS: Intraoperative TEE was performed in all patients. MEASUREMENTS AND MAIN RESULTS: The left ventricular EDA was measured at the midpapillary level, excluding the papillary muscles. Mean EDA for patients with normal left ventricular function, defined by fractional area change (FAC) 0.50 or greater, was 10.66 cm2 and when indexed to body surface area was 5.6 cm2/m2. The EDA was greater in patients with impaired left ventricular function (FAC < 0.50). Mean EDA was 14.84 cm2, and EDA/body surface area was 7.8 cm2/m2. In patients with FAC 0.50 or greater, mean peak pulmonary vein Doppler velocities were 46.10 cm/sec (systole), 31.71 cm/sec (diastole), and 1.50 (ratio systole to diastole). Mean peak mitral inflow Doppler velocities were 57.25 cm/sec (early diastole), 57.21 cm/sec (late diastole), and 1.10 (ratio early to late), and deceleration time was 216 msec. Age, sex, and left ventricular function were not significant predictors of Doppler variables. CONCLUSIONS: Values are presented for a predominantly white population undergoing cardiac surgery. Left ventricular dysfunction is associated with increased left ventricular EDA measurements.     

Ventricular volume, chamber stiffness, and function after anteroapical aneurysm plication in the sheep

OBJECTIVE: The success of left ventricular aneurysm plication depends on how the procedure affects both end-systolic elastance and diastolic compliance and how those changes affect ventricular function (stroke work/end-diastolic volume [PRSW] and stroke volume/end-diastolic pressure [Starling] relationships). METHODS: Five male Dorsett sheep were surgically instrumented with coronary artery snares, an inferior vena caval occluder, and an ascending aortic ultrasonic flow probe. One week later an anteroapical myocardial infarction was produced by tightening the coronary snares. Ten weeks after myocardial infarction, the left ventricular aneurysm was plicated. Absolute left ventricular volume was measured by long-axis transdiaphragmatic echocardiography, and relative changes in left ventricular volume were measured with a conductance catheter. End-systolic elastance, diastolic compliance, PRSW, and Starling relationships were measured immediately before myocardial infarction, 10 weeks after myocardial infarction (immediately before plication), and immediately after and 6 weeks after aneurysm plication. RESULTS: After plication, end-diastolic and end-systolic left ventricular volumes return to preinfarction values. The slopes of end-systolic elastance, diastolic compliance, and PRSW decrease 10 weeks after myocardial infarction, increase with aneurysm plication, and then decrease 6 weeks after aneurysm plication. The Starling relationship undergoes a downward parallel shift with aneurysm plication. CONCLUSION: Aneurysm plication abruptly decreases left ventricular volume and diastolic compliance, increases end-systolic elastance and PRSW, but decreases the Starling relationship. The net effect on left ventricular function is mixed. Furthermore, left ventricular remodeling 6 weeks after aneurysm plication causes left ventricular volume, end-systolic elastance, diastolic compliance, PRSW, and the Starling relationship to return to preplication values.     

Echocardiographic findings using tissue velocity imaging following passive containment surgery with the Acorn CorCap cardiac support device.

OBJECTIVE: To echocardiographically evaluate the effects of passive containment surgery using the CorCap Cardiac Support Device in heart failure patients with dilated cardiomyopathy. METHODS: Twelve patients with dilated cardiomyopathy subjected to cardiac surgery received the Cardiac Support Device. Patients with ischemic cardiomyopathy (n=5) underwent coronary artery bypass surgery receiving 1-3 bypass grafts. In the idiopathic cardiomyopathy group (n=7), mitral valve annuloplasty was performed in five patients while two patients received the Cardiac Support Device only. RESULTS: Following surgery there was a gradual, sustained improvement in cardiac dimensions (decreased left ventricular end-diastolic diameter and left ventricular end-systolic diameter) combined with an increase in functional status (6-min walk and NYHA class). Concomitantly there was a marked decrease in right ventricular function (decrease in tricuspid annular systolic and diastolic velocities) while the left ventricular function (mitral annular systolic and diastolic velocities) and output (ejection fraction, stroke volume) remained unchanged. CONCLUSIONS: Addition of the Cardiac Support Device to conventional cardiac surgery improves patient status and decreases left ventricular size in heart failure patients with dilated cardiomyopathy. The positive effect on left ventricular dimensions is not accompanied by any improvement in cardiac output but rather right ventricular dysfunction, although the functional significance of this is unclear.     

Desflurane, Sevoflurane, and Isoflurane Affect Left Atrial Active and Passive Mechanical Properties and Impair Left Atrial-Left Ventricular Coupling In Vivo: Analysis Using Pressure-Volume Relations

Background: The effects of volatile anesthetics on left atrial function in vivo have not been described. The authors tested the hypothesis that desflurane, sevoflurane, and isoflurane alter left atrial mechanics evaluated with invasively derived pressure-volume relations.

Methods: Barbiturate-anesthetized dogs (n = 24) were instrumented for measurement of aortic, left atrial, and left ventricular pressures (micromanometers) and left atrial volume (orthogonal sonomicrometers). Left atrial contractility and chamber stiffness were assessed with end-systolic and end-reservoir pressure-volume relations, respectively, obtained from differentially loaded diagrams. Relaxation was determined from the slope of left atrial pressure decline after contraction. Stroke work and reservoir function were assessed by A and V loop areas, respectively. Left atrial-left ventricular coupling was determined by the ratio of left atrial contractility and left ventricular elastance. Dogs received 0.6, 0.9, and 1.2 minimum alveolar concentration desflurane, sevoflurane, or isoflurane in a random manner, and left atrial function was determined after 20-min equilibration at each dose.

Results: Desflurane, sevoflurane, and isoflurane decreased heart rate, mean arterial pressure, and maximal rate of increase of left ventricular pressure and increased left atrial end-diastolic, end-systolic, and maximum volumes. All three anesthetics caused dose-related reductions in left atrial contractility, relaxation, chamber stiffness, and stroke work. Administration of 0.6 and 0.9 minimum alveolar concentration desflurane, sevoflurane, and isoflurane increased V loop area. All three anesthetics decreased the ratio of stroke work to total left atrial pressure-volume diagram area, increased the ratio of conduit to reservoir volume, and reduced left atrial contractility-left ventricular elastance to equivalent degrees.     

Usefulness of long axis M-mode echocardiographic measurements for optimum dialysis in patients on maintenance hemodialysis: comparison with changes in plasma levels of atrial natriuretic peptide and brain natriuretic peptide

It has been suggested that analyzing the left ventricular long axis motion can result in the sensitive detection of cardiac functional disorders. AIM: To evaluate the usefulness of left ventricular long axis indices in managing patients on maintenance hemodialysis. METHODS: Eighteen hemodialysis patients (mean age 51 +/- 10 years) as well as 16 healthy persons (mean age 49 +/- 9 years) were examined. Echocardiograms were recorded, and the plasma concentrations of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were measured before and after a session of hemodialysis. The following parameters were measured: the left atrial diameter (LAD) and end-diastolic left ventricular diameter (LVDd) from M-mode echocardiograms, the end-diastolic LV volume (LVEDV) and ejection fraction (EF) from 2-D echocardiography, the E/A ratio from transmitral Doppler, the atrial systolic excursion of long axis motion of the mitral ring (ALAM) and maximal lengthening rate of the mitral ring toward the left atrium during the early diastolic phase (MLRe) from LV long axis M-mode echocardiograms. RESULTS: LAD, LVDd, LVEDV, and ALAM showed a positive correlation with plasma levels of ANP and BNP. EF, the E/A ratio, and MLRe showed a negative correlation with plasma levels of ANP and BNP. Changes in ALAM and plasma levels of ANP during hemodialysis were larger in the subgroup of ALAM < or = 0.55 cm before hemodialysis than in the subgroup of ALAM < 0.55 cm before hemodialysis. CONCLUSION: These results indicate that the left ventricular long axis index can detect a disorder of left ventricular diastolic function, and that a hemodialysis patient whose ALAM before hemodialysis is < 0.55 cm is dialyzed with good volume control conditions.     

Reasonable and effective volume reduction of a giant left atrium associated with mitral valve disease

Severe left atrial enlargement associated with mitral valve disease has been known to carry a poor prognosis in patients undergoing mitral valve repair or replacement. There are several reasons why left atrial size can have a significantly negative impact on prognosis. A giant left atrium (LA) can cause postoperative respiratory dysfunction by bronchial and pulmonary compression and hemodynamic disturbance subsequent to compression of the posterobasal portion of the left ventricle (LV). Moreover, the presence of a giant LA can increase thromboembolic risk despite anticoagulant therapy after operation. We report a case of a 62-year-old female who had a markedly enlarged LA associated with mitral valve stenosis and regurgitation. The patient, who had severely restrictive and obstructive respiratory dysfunction, underwent mitral valve replacement and left atrial volume reduction with postoperative improvement in hemodynamic and respiratory function. We believe that volume reduction of an enlarged LA, in addition to mitral valve surgery, is important not only because it leads to improvement in heart failure but also because it will relieve compression of the adjacent organs.