Myocardial performance index derived from preejection period: a novel and feasible parameter in evaluation of cardiac performance in patients with permanent atrial fibrillation

Background: Using tissue Doppler echocardiography, we can measure preejection period (PEPa), defined as the interval measured from the onset of QRS to the onset of the systolic mitral annular velocity pattern, isovolumic relaxation time (IVRTa), defined as the interval measured from the end of systolic mitral annular velocity pattern to the onset of diastolic mitral annular velocity pattern, and ejection time (ETa), defined as the interval measured from the onset to the end of systolic mitral annular velocity pattern on the same cardiac cycle. The aim of this study is to test the applicability of PEPa‐derived myocardial performance index (MPI), defined as the ratio of PEPa + IVRTa to ETa, as an indicator of combined left ventricular systolic and diastolic function in patients with permanent atrial fibrillation. Methods: Echocardiographic examination was performed in 54 consecutive patients with permanent atrial fibrillation. Clinical and echocardiographic parameters were compared and analyzed. Results: After a multivariate analysis, the average RR interval on the tissue Doppler image (β=?0.328, P = 0.002), left ventricular ejection fraction (β=?0.260, P = 0.024), and early diastolic mitral annular velocity (β=?0.408, P < 0.001) were the major determinants of PEPa‐derived MPI. Conclusions: PEPa‐derived MPI had a significant correlation with echocardiographic left ventricular diastolic and systolic function. It may be a novel and feasible indicator in assessment of global left ventricular function in patients with permanent atrial fibrillation. (Echocardiography 2011;28:1081‐1087)     

Left Ventricular Diastolic Function and Right Atrial Size Are Important Rhythm Outcome Predictors after Intraoperative Ablation for Atrial Fibrillation

Background: Left ventricular (LV) diastolic function and right atrial (RA) size are not routinely included in preoperative echocardiographic examination in patients undergoing cardiac surgery with concomitant ablation for atrial fibrillation (AF). Objective: To investigate the role of echocardiographic variables including LV diastolic function and RA area in long‐term rhythm outcome prediction, in patients with documented AF undergoing intraoperative ablation concomitant to coronary artery bypass grafting (CABG). Methods: Thirty‐five consecutive patients, scheduled for CABG, and with a history of paroxysmal or permanent AF for 8.5 ± 11.3 years (mean ± SD) (median 5.8 years), were included in this prospective study. Echocardiography was performed prior to and 2.3 ± 0.4 years after the surgical procedure. Results: Both LA and RA areas, LV diastolic function, paroxysmal AF, and sinus rhythm (SR) preoperatively were associated with SR at long‐term follow‐up. In the multivariate analysis, RA area (P = 0.004), and decreased LV diastolic function preoperatively, measured as the maximal LV long‐axis relaxation velocity (P = 0.02), predicted SR at follow‐up. Conclusions: RA size and LV diastolic function may be important variables in prediction of long‐term rhythm outcome after intraoperative ablation for AF. (Echocardiography 2010;27:961‐968)     

Importance of the index of myocardial performance in evaluation of left ventricular function

The index of myocardial performance (MPI) has been used as an easily obtainable parameter that reflects both systolic and diastolic functions of the myocardium and correlates closely with invasive measurements. This study investigated the importance of MPI on assessment of left ventricular function in patients with critical coronary artery disease. Methods: We studied 82 patients who had coronary angiography and echocardiography. Patients in Group A were without critical coronary stenosis (n = 37, 17 females, 20 males, mean age 54 +/- 11 years) and patients in Group B had critical coronary stenosis (> 70%) without previous myocardial infarction (n = 45, 18 female, 27 male, mean age 57 +/- 10 years). Using echocardiographic parameters, left ventricular isovolumetric relaxation time (IRT), isovolumetric contraction time (ICT), ejection time (ET), ratio of velocity time integrals (vti) of early and late diastolic mitral flow (E/Avti), E deceleration time (EDT), MPI [(IRT + ICT) / ET], ejection fraction (EF), and fractional shortening (FS) were calculated. During cardiac catheterization, Dp/Dt [(diastolic blood pressure - left ventricular end diastolic pressure) / ICT] was calculated. Results: There were significant differences in IRT, EDT, E/Avti, and the MPI between Groups A and B (95.9 +/- 14.7 and 113.4 +/- 14.3 msec, P < 0.001; 164.5 +/- 44.8 and 186.2 +/- 33.6 msec, P < 0.05; 1.51 +/- 0.45 and 1.24 +/- 0.80 msec, P < 0.05; and 0.45 +/- 0.08 and 0.53 +/- 0.07 msec, P < 0.001, respectively), but there were no significant differences in ICT, ET, EF, FS, and Dp/Dt between the two groups. Both groups showed a close correlation between MPI and Dp/Dt (r = - 0.78 for Group A and r = - 0.82 for Group B). There were no significant differences in heart rate and systolic and diastolic blood pressure between the two groups. Conclusion: These data suggest that MPI may be a useful parameter and an early indicator of left ventricular dysfunction in patients with critical coronary artery disease and normal systolic function.     

The Doppler-derived myocardial performance index is determined by both left ventricular systolic and diastolic function as well as by afterload and left ventricular mass

OBJECTIVES: To investigate if the newly developed Doppler-derived myocardial performance index (MPI, also denoted TEI-index) is associated with variables reflecting both left ventricular (LV) systolic and diastolic function, as well as variables reflecting preload, afterload, and LV geometry. MATERIAL: An echocardiographic examination including Doppler was carried out in 446 men aged 70 in a population-based survey (the ULSAM-study, Uppsala Longitudinal Study of Adult Men). RESULTS: In multiple regression analysis, MPI was independently associated with ejection fraction (P < 0.001), E/A ratio (P < 0.001), total peripheral resistance index (P < 0.001), stroke volume to pulse pressure ratio (P < 0.02), stroke index (P < 0.01), and LV mass (P < 0.04), but not with heart rate or blood pressure. CONCLUSION: The echocardiographically determined myocardial performance index is determined by both LV systolic and diastolic function as well as by afterload and left ventricular mass.     

The myocardial performance index in patients with aortic stenosis

OBJECTIVES: This study was designed to determine the effect of chronic afterload on a Doppler-derived myocardial performance index (MPI) combining both systolic and diastolic left ventricular dysfunction. METHODS: The study included 36 patients with a diagnosis of aortic stenosis and 36 normal subjects. Doppler-derived myocardial performance index (MPI), defined as the sum of the isovolumic contraction time and isovolumic relaxation time divided by ejection time, was measured from the mitral valve inflow and left ventricular outflow velocity patterns and was then related to the aortic valve area, valve gradient, and other echocardiographic variables. RESULTS: The values of the Doppler-derived MPI in the patients with aortic stenosis were significantly higher than those in the controls (0.54 +/- 0.20 vs 0.38 +/- 0.04, respectively; P < 0.001). Transmitral deceleration time and the E/A ratio ( r = 0.47 and r = 0.35, respectively; P < 0.05) were significant univariate correlates, and mitral deceleration time was the only significant correlate of MPI. However the index did not correlate with aortic valve area, peak and mean valve gradients, left ventricular mass, or age. CONCLUSIONS: Doppler-derived MPI reflects severity of global left ventricular dysfunction in patients with aortic stenosis and may be of clinical value in this patient population.     

Evaluation of Right Ventricular Function During CABG: Transesophageal Echocardiographic Assessment of Hepatic Venous Flow Versus Conventional Right Ventricular Performance Indices

The vulnerability of right ventricle (RV) to ischemic insult during cardiac surgery is being increasingly recognized. This study aims to evaluate right ventricular function by measuring hepatic venous flow (HVF) patterns using intraoperative transesophageal echocardiography (TEE), and to compare HVF with other conventional two-dimensional echocardiographic and hemodynamic indices of RV performance. Patients undergoing coronary artery bypass grafting (CABG) were studied intraoperatively using a multiplane dual frequency 5/3.7-MHz phased array transducer, a pulmonary artery catheter, and an arterial catheter. Peak velocities and time velocity integrals of HVF pattern were studied. Peak systolic-diastolic ratio (S/D) of biphasic HVF and reverse flow ratio (% reverse flow/forward flow = % RF/FF) were also examined. Two-dimensional echocardiographic measurements included: (1) transverse plane long-axis (LA) and short-axis (SA) planimetered areas expressed as ratios; LA maximum major and minor-axis shortening fractions; (2) tricuspid annular plane systolic excursion (TAPSE) ratio. All data were obtained after induction of anesthesia (stage 1), after sternotomy (stage 2), aftercardiopulmonary bypass (CPB) (stage 3), and after sternal closure (stage 4). Pre-CPB all 35 patients had biphasic HVF by Doppler. In 31 patients peak S/D ratio was >1. After CPB, there was significant reduction in systolic forward flow (S wave), along with an increase in late systolic reverse flow (V wave) and an increase in % RF/FF. At this stage TAPSE ratio decreased (pre CPB 0.33 +/- 0.12 vs post CPB 0.30 +/- 0.11). There was simultaneous decrease in 2-D long-axis LA (pre CPB 0.52 +/- 0.11 vs post CPB 0.31 +/- 0.01) and max major axis LA (pre CPB 0.38 +/- 0.06 vs post CPB 0.31 +/- 0.11). Max major axis LA correlated significantly with changes in right atrial pressure (P < 0.05). Tricuspid annular motion diminished significantly at sternal closure. Hepatic systolic forward flow and TAPSE ratio can be an indirect measure of RV systolic functions in correlation with maximum major axis LA changes. Evaluation of HVF provides unique insight into right ventricular dynamics. It is an easy, safe, and sensitive method for assessing RV functions intraoperatively.     

Ischemic mitral valve repair: predictive significance of restrictive left ventricular diastolic filling

AIM: The aim of the present study was to evaluate the impact of left ventricular (LV) diastolic filling impairment on postoperative results in patients with low LV ejection fraction (EF) undergoing combined coronary artery bypass grafting (CABG) and mitral valve (MV) repair. METHODS AND RESULTS: Study population consisted of 53 patients with ischemic MV incompetence and LV systolic dysfunction (mean EF-26.1 +/- 6%), who underwent CABG with MV repair. Patients were divided into three groups according to the LV diastolic filling pattern. Study protocol included evaluation of perioperative mortality (30 days inhospital mortality), NYHA functional class, and two-dimensional Doppler echocardiographic examination preoperatively, 10-14 days, and 12 months after surgery. The highest perioperative mortality rate (33.3%), unimproved functional status (in 78.5% of the patients, NYHA functional class remained unchanged late after surgery), and hemodynamic deterioration (LV dilatation, progression of mitral regurgitation (MR) was observed in the restriction group). Though early after surgery, MR reduction was significant in this group, at even one year after surgery 85.7% of patients presented with >grade 1 of MR (P < 0.05). Logistic regression analysis showed that restrictive LV diastolic filling is an important independent preoperative marker (P = 0.035) of progression of MR late after MV repair. CONCLUSION: In patients with severe LV dysfunction undergoing combined CABG and MV repair, restrictive LV diastolic filling pattern is an important preoperative marker of high perioperative mortality rate, further negative remodeling of LV, and progression of mitral regurgitation late after MV repair.     

Reliability of Doppler methods in the evaluation of the left ventricular systolic function in patients with idiopathic dilated cardiomyopathy

BACKGROUND: There are many new methods for evaluating the left ventricle (LV) systolic function. The aim of this study was to compare the methods, which evaluate the systolic function such as Simpson's method, myocardial performance index (MPI), systolic S(m) wave, and dp/dt value of the mitral regurgitation. METHODS: Forty patients (27 male, 13 female, mean age 52.5 +/- 18.2 years) with idiopathic dilated cardiomyopathy and 40 healthy subjects (27 male, 13 female, mean age 49.3 +/- 10.8 years) were included in the study. All patients and controls underwent echocardiographic examination by M-mode, two-dimensional, pulsed-wave (PW) and continuous wave Doppler and tissue Doppler imaging (TDI). The MPI were measured by the summation of the isovolumetric contraction and relaxation times division of the LV ejection time, with both PW and TDI methods. RESULTS: The cardiac chamber dimensions, MPI, and modified MPI were greater, LV ejection fraction and TDI S(m) wave were lower in the patients compared to the controls (P < 0.001). The LV ejection fraction of patients calculated by Simpson's method compared with novel methods. Value of dp/dt (P = 0.010, r = 0.546), MPI (P = 0.002, r =-0.470) and modified MPI (P = 0.038, r =-0.330) were related to the LV ejection fraction. Tissue Doppler Systolic S(m) wave had a modest correlation with LV ejection fraction (P < 0.001, r = 0.604). CONCLUSION: Doppler and tissue Doppler imaging methods correlate with traditional echocardiographic methods and can be used reliably and safely for left ventricular performance regardless of the patient's echogenity.     

Myocardial performance index for detection of subclinical abnormalities in patients with sarcoidosis

Aim

The aim of this study was to evaluate ventricular functions in patients with sarcoidosis without an obvious heart disease by using tissue Doppler-derived left and right ventricular myocardial performance index (MPI).

Methods

The study population included 45 patient with sarcoidosis (29 men, 16 women; mean age, 44±10 years, mean disease duration, 4.2±2.7 years) and 45 healthy control subjects (31 men, 14 women; mean age, 41±8 years). Cardiac functions were determined using echocardiography, consisting of standard two-dimensional and conventional Doppler and tissue Doppler imaging (TDI). Myocardial tissue Doppler velocities [peak systolic (Sa), early diastolic (Ea), and late diastolic velocities (Aa)] were recorded using spectral pulsed Doppler from the LV free wall, septum, and RV free wall from the apical four chamber view. MPI was also calculated by TDI.

Results

The conventional echocardiographic parameters and tissue Doppler measurements were similar between the patients and controls. Left ventricular MPI (0.490±0.092 vs. 0.396±0.088, P=0.010) and right ventricular MPI (0.482±0.132 vs. 0.368±0.090, P=0.006) were significantly higher in patients with sarcoidosis than the control subjects. There was a correlation between the disease duration and right and left ventricular MPI (r=0.418, P=0.005; r=0.366, P=0.013, respectively). There was also a correlation between the systolic pulmonary arterial pressure and right ventricular MPI but not left ventricular MPI (r=0.370, P=0.012; r=0.248, P=0.109, respectively). In receiver operating characteristics curve analysis, the cutoff value of left ventricular MPI >0.46 had 92% sensitivity and 64% specificity in predicting left ventricular diastolic dysfunction.

Conclusions

We have demonstrated that tissue Doppler-derived myocardial left and right ventricular MPI were impaired in sarcoidosis patients, although systolic function parameters were comparable in the patients and controls, showed a subclinic impaired ventricular functions in patients with sarcoidosis.     

Left ventricular function and exercise capacity in patients with slow coronary flow

Background: Endothelial and microvascular dysfunction have been implicated in slow coronary flow (SCF). How and to what extent do these etiological factors affect left ventricular (LV) function and exercise capacity? Aim: The aim of the study was to evaluate LV systolic and diastolic function by pulsed tissue Doppler imaging (TDI) in SCF patients and their effects on exercise capacity. Subjects and methods: Sixty SCF patients and 20 control subjects were included in the study. Echocardiographic examination, treadmill exercise test, and TDI were performed. Isovolumic myocardial acceleration (IVA) and myocardial performance index (MPI) were measured. Results: TDI mean parameters for systolic and diastolic LV function were significantly impaired in SCF group with decreased Sa, IVA, Ea/Aa, and increased MPI (0.31 ± 0.06 vs. 0.26 ± 0.04, P < 0.01) compared to control. There was significant correlation between thrombolysis in myocardial infarction (TIMI) frame count and TDI mean parameters for LV systolic function (Sa & IVA, r =?0.53, P < 0.01 & r =?0.36, P < 0.05, respectively). Mean TIMI frame count was correlated with MPI and E/Ea. SCF patients had poorer peak exercise capacity than the controls (9.9 ± 1.9 METs vs. 12.7 ± 2.3, P < 0.01) with significant negative correlation with mean TIMI frame count (r =?0.46, P < 0.01). Conclusion: There is impairment of LV systolic and diastolic function in SCF patients with clinical impact on exercise capacity which emphasizes the importance of close follow‐up of these patients for risk stratification. (Echocardiography 2012;29:158‐164)     

Ambulatory pulse pressure, left ventricular hypertrophy and function in arterial hypertension

BACKGROUND: A wide pulse pressure (PP) can provide important risk assessment information about myocardial infarction, carotid artery atherosclerosis, and global cardiovascular risk. Ambulatory pulse pressure (APP) does not have a well-known prognostic value in hypertensive patients. METHODS:To evaluate the relationship among high APP, atrial volumes, and cardiac function, an observational study was performed on 108 untreated non-elderly hypertensive patients (mean age 54.23 +/- 7.12). Twenty-four-hour ambulatory blood pressure monitoring, Doppler and echocardiographic measurements of systolic, diastolic function, left and right atrial volumes, left ventricular mass index and dimensions, were performed in subjects with both clinic and APP > 60 mmHg (APP1 Group). A control group of hypertensive selected subjects with both clinic and APP < 60 mmHg was chosen (APP 2 Group). RESULTS: The APP1 group showed left atrial volume enlargement, high left ventricular mass index, and impaired diastolic function. A positive correlation was found in the APP1 group results among left ventricular end diastolic diameter (r = 0.39, P < 0.01), left atrial volume (0.38, P < 0.05), and left ventricular mass index (r = 0.33, P < 0.05); clinic PP showed a statistically significant correlation with left atrial volume, left ventricular end diastolic diameter, and left ventricular mass index only in the APP1 group. CONCLUSIONS: These results suggest that elevated APP can be considered an effective predictor of cardiovascular risk in hypertensive subjects. In these patients echocardiographic evaluation of left ventricular function and morphology can increase the prognostic value of PP.     

Predictors of perioperative mortality after coronary artery bypass grafting in the elderly

BACKGROUND: Coronary artery bypass grafting (CABG) is associated with higher operative risk in the elderly compared to younger patients. The aim of this study was to evaluate risk factors for perioperative mortality after CABG in the elderly. METHODS: We investigated 325 consecutive patients aged 75 or over undergoing isolated CABG at our institution. We analyzed the patients' characteristics and perioperative outcome. Patients were divided into survivors and non-survivors; risk factors and complications were compared. Based on this, we performed a multivariate logistic regression analysis to determine independent risk factors for perioperative mortality. RESULTS: Non-survivors of CABG more often suffered from concomitant extracardiac atherosclerosis (non-survivors, 62.2 %; survivors, 40.6 %; p = 0.013) as well as from renal insufficiency preoperatively (non-survivors, 35.1 %; survivors 8.0 %; p < 0.0001). A trend towards higher incidences of impaired left ventricular function (non-survivors, 37.8 %; survivors, 29.9 %; p = 0.105) and a history of recent myocardial infarction (non-survivors, 29.7 %; survivors, 17.0 %; p = 0.061) were found in non-survivors compared to survivors. Furthermore, non-survivors more often underwent CABG with cardiopulmonary bypass (CPB non-survivors, 96.1 %; survivors 70.6 %; p = 0.0005). Multivariate logistic regression analysis revealed that preoperatively impaired renal function (OR: 2.857, p < 0.0001), use of CPB (OR: 5.952, p = 0.0175), extracardiac atherosclerosis (OR: 1.581, p = 0.0228), and recent myocardial infarction (OR: 1.574, p = 0.0405) were independent risk factors for perioperative mortality. Comparison of patients undergoing CABG with or without CPB reveals that patients operated without CPB had a higher preoperative risk than patients undergoing CABG with CPB. CONCLUSION: These results show that besides impaired renal function, extracardiac atherosclerosis, and history of recent myocardial infarction, the use of CPB is a major risk factor for CABG in the elderly. Perioperative mortality and morbidity can be significantly reduced if CPB is avoided.     

高原地区体外循环应用超滤对儿童术后右心室功能的影响

目的　探讨高原地区体外循环 (CPB)中应用血液超滤技术对心内直视手术后右心室功能的保护作用。方法　选择在海拔 370 0m开展的CPB心脏手术患者 12例 ,根据CPB过程中有无应用血液超滤技术 ,将患者分成血液超滤组和对照组 ,分别于CPB前、CPB结束时以及CPB后 1h、3h、6h、12h、2 4h ,测定肺动脉平均压 (MPAP)、右心房压 (RAP)、右心室舒张末容积指数 (RVEDVI)、右心室射血分数 (RVEF)、心脏指数 (CI)、右心室每搏容量指数 (RVSI)和肺血管阻力指数 (PVRI)。结果　CPB结束和CPB后 6h内 ,对照组MPAP、RVEDVI以及RAP均较CPB前明显升高 (P <0 0 5 ) ,而RVEF、CI和RVSI较CPB前降低 (P <0 0 5 ) ;CPB后 12h对照组MPAP、RVEDVI以及RAP均逐渐减低 ,但RVEF、CI和RVSI仍未高于CPB前 ;血液超滤组RVEF、CI和RVSI在CPB后各时间点均显著高于对照组 (P <0 0 5 )。结论　高原地区在CPB下施行心内直视手术后早期 ,右心室心肌收缩力显著降低 ,右心室的泵血功能受损 ;CPB中应用血液超滤技术有利于CPB后心脏泵血功能的恢复。     

Reference values from M-mode and Doppler echocardiography for normal Syrian hamsters.

AIMS: Echocardiography has recently been introduced to small animal research, allowing serial measurements of cardiac diseases. In addition, the hamster model has been increasingly used, as it mimics many human heart conditions. However, no reference range of echocardiographic values reflecting normal left ventricular (LV) function exists for hamsters. The purpose of this study was to provide one. METHODS AND RESULTS: The study group consisted of 118 10-week-old, female, Syrian golden hamsters, which underwent high-resolution echocardiography. LV mass was calculated using the corrected cube formula, and LV systolic and diastolic function were assessed by fractional shortening and mitral inflow pulsed-wave Doppler, respectively. The myocardial performance index (MPI) measured the time spent in isovolumic activity and reflected both systolic and diastolic function. The mean+/-SD LV mass, fractional shortening, and MPI were 0.19+/-0.04 g, 44.7+/-6.6%, and 0.39+/-0.1, respectively. E and A waves were differentiated in 52% of all animals. Logistic regression adjusted with a cutoff of 378 bpm revealed that the risk of E/A wave fusion was 35 times greater (95% CI: 12.6; 98.4) in animals with a heart rate >378 bpm. CONCLUSION: This study documents echocardiographic characteristics in normal Syrian hamsters, which can be used as control values for future studies.     

Echocardiographic diastolic dysfunction and magnetic resonance infarct size in healed myocardial infarction treated with primary angioplasty

Background: After acute myocardial infarction (MI) the severity of diastolic dysfunction by echocardiography represents an independent prognostic marker. However, the mechanisms whereby diastolic dysfunction portends an increased risk after MI are not fully understood. We investigated the relationship between echocardiographic diastolic dysfunction severity and infarct size quantitatively measured by contrast‐enhanced magnetic resonance (ce‐MR). Methods: Cross‐sectional prospective study. We quantified “healed” infarct size by ce‐MR measuring the percentage of delayed enhancement with respect to left ventricular mass and diastolic function by Doppler echocardiography. Both exams were scheduled at least 1 month after a first acute ST segment elevation MI (STEMI) successfully treated with primary angioplasty and stenting. To increase the specificity, individual echocardiographic parameters were integrated to grade global diastolic function in 4 grades: normal diastolic function, impaired relaxation with normal, or near‐normal filling pressures; impaired relaxation with moderate elevation of filling pressures, and impaired relaxation with marked elevation of filling pressures, “restrictive filling.” Results: We prospectively enrolled 52 patients (mean age 62 ± 13 years, 77% men). ce‐MR and echocardiography were performed 48 ± 15 days after the MI. There was a significant but modest correlation between diastolic function grade and infarct size (r = 0.423, P = 0.002), which was independent of global and regional systolic function and persisted after further adjustment for age, sex, body surface area, left ventricular mass, end‐diastolic volumes, and sphericity index (all P < 0.05). Among single echocardiographic variables, infarct size correlated best with tissue Doppler velocities Em (r =?0.307, P = 0.03), Am (r =?0.39, P = 0.005), and flow propagation velocity (r =?0.34, P = 0.015). Conclusions: In healed STEMI successfully treated with primary angioplasty and stenting, diastolic function grade was independently albeit weakly correlated with infarct size. Therefore, the increased risk of diastolic dysfunction after MI is not fully explained by infarct size     

Improvement in diastolic left ventricular function after coronary artery bypass grafting as assessed by recordings of mitral annular velocity using Doppler tissue imaging.

AIMS: The aim of the study was to evaluate the changes in diastolic function after coronary artery bypass grafting (CABG), using pulsed-wave Doppler tissue imaging (DTI). METHODS: Fifty-three patients with coronary artery disease were studied before and 3 and 12 months after CABG. Using pulsed-wave DTI, the mitral annular velocities were determined at 4 sites in the left ventricle (LV). Patients were also examined with dobutamine stress echocardiography and myocardial scintigraphy before and 3 months after CABG. RESULTS: The conventional transmitral velocity profiles were unchanged after CABG. DTI showed a marked improvement in diastolic LV function after CABG (early diastolic velocity: 7.5+/-1.9, 8.2+/-1.7 and 9.3+/-2.7 cm/s before and 3 and 12 months after CABG, respectively, P < 0.01). The improvement in early diastolic velocity was more pronounced in patients showing no sign of residual ischemia in comparison to those with residual ischemia determined by myocardial scintigraphy (7.41+/-2.04 vs. 9.25+/-2.61 cm/s, P < 0.01 in the nonischemic group; 7.29+/-2.16 vs. 8.41+/-2.55 cm/s, n.s., in the ischemic group). Before CABG, a significant increase in the systolic velocity (6.4+/-1.3 vs. 8.7+/-2.5 cm/s, P < 0.001), but not the early diastolic velocity (7.6+/-1.9 vs. 8.0+/-2.2 cm/s), was noted during stress echocardiography. Three months after CABG, both the systolic (6.5+/-1.3 vs. 9.3+/-2.8 cm/s, P < 0.001) and the early diastolic velocities (8.1+/-1.8 vs. 10.3+/-2.2 cm/s, P < 0.001) improved during stress echocardiography. CONCLUSION: The results of the present study show that diastolic function improves at rest and under stress in patients after CABG. The improvement was seen only in patients without postoperative signs of reversible ischemia.     

Relation of brain natriuretic peptide to myocardial performance index in adults with congenital heart disease

Myocardial performance index (MPI) is an echocardiographic Doppler-derived measure of ventricular function previously validated in patients with congenital heart disease. It may be preferred over conventional noninvasive measures of ventricular function in patients with complex anatomy because it is dependent on neither geometric shape nor heart rate. Brain natriuretic peptide (BNP) is a predictor of systolic and diastolic dysfunction in anatomically correct hearts. The correlation of BNP to MPI in patients with congenital heart disease was determined. Fifty-four adults with congenital heart disease were evaluated. BNP was measured using standardized assays. Doppler echocardiography was performed within 6 months of BNP assay. There were no changes in clinical status during this interval. An experienced observer was blinded and evaluated all echocardiographic images, and MPI and ejection fraction (EF) were determined. Left ventricular (LV) or univentricular MPI was calculated in 34 patients and right ventricular (RV) MPI was calculated in 23 patients. Pearson's correlation coefficient test showed that BNP significantly correlated with LV/univentricular MPI (r = 0.461, p = 0.006) and RV MPI (r = 0.748, p <0.0001), whereas LV/univentricular EF and RVEF had no significant correlation with BNP (r = -0.189, p = 0.172; r = 0.066, p = 0.729, respectively). In patients with congenital heart disease, BNP correlated significantly with MPI, but not with LV, RV, or univentricular EF. This is particularly true in patients with geometrically variable right ventricles in which EF may be more difficult to assess. In conclusion, these findings emphasize the unique ability of both BNP and MPI to assess global ventricular function in geometrically complex hearts.     

Infusion of low-dose vasopressin improves left ventricular function during separation from cardiopulmonary bypass: a double-blind randomized study

We aimed to investigate whether low-dose vasopressin administered to patients undergoing coronary artery bypass grafting (CABG) surgery with preexisting mild to moderate systolic dysfunction can produce sustained improvement in cardiac function. This double-blind randomized study was conducted in a hospital where a single anesthetic and surgical team performed elective CABG. Twenty patients aged 32-61 years who underwent elective CABG between January 2007 and December 2007 were enrolled in this study. The patients randomly received either vasopressin 0.03 IU/min (Group A) or normal saline (Group B) in equal volume for 60 min after cardiopulmonary bypass (CPB). The cardiac output, cardiac index, stroke volume index, fractional area of contraction and systemic vascular resistance index were significantly higher in Group A than in Group B. Adrenaline (mean dose: 0.06 μg/kg x min-1) was required in seven patients from Group B but in none of the Group A patients on initial separation from CPB (P< 0.05). Of the 10 patients in Group B, five required phenylepherine to maintain the mean arterial pressure (MAP) >65 mmHg, whereas none of the Group A patients required phenylephrine for MAP regulation (P< 0.05). We conclude that Infusion of low-dose vasopressin for patients with mild to moderate left ventricular systolic dysfunction during separation from CPB is beneficial for the postoperative hemodynamic profile, reduces the catecholamine doses required and improves left ventricular systolic function.     

米力农治疗冠状动脉旁路移植术后左室功能障碍的短期疗效

目的：评价米力农对冠状动脉搭桥术（CABG）中左室功能障碍患者短期疗效。方法：62例CABG术后低心排患者（左心室射血分数〈35％）纳入该研究。将患者随机分为米力农组[n=31,米力农（50μg／kg）静脉注射并于术后24h0．5μg／（kg·min）持续泵入]和对照组（n=31,生理盐水作为安慰剂）。左室功能障碍采用血流动力学参数和经胸廓的超声心动图进行评估。结果：两组患者的基线水平有差异,术前米力农组患者的左心室射血分数低于对照组,术后两组无明显差异。米力农组的血清肌酸磷酸激酶（CK）及其同工酶（CK—MB）、发生心肌缺血或梗死和应用正性肌力药物的时间均显著低于对照组（P〈0．05,P〈0．01）。室性心律失常、使用主动脉内球囊反博的时间、机械通气和24h病死率两组无明显差异。结论：对于接受CABG,尤其是左室射血分数较低的的患者,应用米力农可以减少心肌梗死发生的风险和应用正性肌力药物支持的时间。     

心肌肽素在心脏手术中对心肌的保护作用的临床研究

目的:考察心脏瓣膜替换术和冠状动脉旁路移植术(CABG)患者在体外循环停跳液中使用心肌肽素的安全性及对心肌的保护作用。方法:选择心脏瓣膜替换术患者44例(瓣膜替换组,又随机分为对照患者、用药患者各22例),CABG患者65例(CABG组,又随机分为对照患者33例、用药患者32例)。2组用药患者在麻醉后,静脉滴注心肌肽素1 mg/kg,30分钟给药完毕;第1次灌注时在停跳液中一次性加入心肌肽素2 mg/kg。2组对照患者给予相应的甘露醇。观察围术期血流动力学,心肌组织形态学,心肌酶学及肌钙蛋白含量的变化。结果:所有受试患者均顺利完成试验,未见明显不良反应,均康复出院。CABG组心肌组织形态学:用药患者在用药前心肌组织病变分值较对照患者显著升高(P<0.01),而用药后较对照患者显著降低(P<0.01);用药患者体外循环后心肌组织病变分值较体外循环前显著降低(P<0.01);而对照患者体外循环后心肌组织病变分值较体外循环前显著升高(P<0.01)。瓣膜替换组心肌组织形态学:体外循环前心肌组织病变分值用药患者虽高于对照患者,但无统计学意义;体外循环后用药患者显著低于对照患者(P<0.01);体外循环后对照患者心肌组织病变分值较体外循环前显著升高(P<0.01),用药患者虽有降低,但无统计学差异(P>0.05)。结论:心肌肽素在心脏瓣膜替换术和CABG患者体外循环停跳液中使用是安全的,而且对心肌有一定保护作用。