Mechanism of recurrent/persistent ischemic/functional mitral regurgitation in the chronic phase after surgical annuloplasty: importance of augmented posterior leaflet tethering.

BACKGROUND: Surgical annuloplasty can potentially hoist the posterior annulus anteriorly, exaggerate posterior leaflet (PML) tethering, and lead to recurrent ischemic/functional mitral regurgitation (MR). Characteristics of leaflet configurations in late postoperative MR were investigated. METHODS AND RESULTS: In 30 patients with surgical annuloplasty for ischemic MR and 20 controls, the anterior leaflet (AML) and PML tethering angles relative to the line connecting annuli, posterior and apical displacement of the coaptation and the MR grade were measured by echocardiography before, early after, and late after surgery. Early after surgery, grade of MR and AML tethering generally decreased (P<0.01), whereas PML tethering significantly worsened (P<0.01). Nine of the 30 patients showed recurrent/persistent MR late after surgery. Compared with patients without late MR, those with the MR showed similar reduction in the annular area, significant re-increase in posterior displacement of the coaptation, and progressive worsening in PML tethering (P<0.05) late after surgery in comparison to the early phase. Both preoperative MR and late postoperative MR were significantly correlated with all tethering variables in univariate analysis. Although apical displacement of the coaptation was the primary determinant of preoperative MR (r2=0.60, P<0.0001), increased PML tethering was the primary determinant of late MR (r2=0.75, P<0.0001). CONCLUSIONS: Whereas both leaflets tethering is related to preoperative ischemic MR, both leaflets tethering but with predominant contribution from augmented and progressive PML tethering is related to recurrent/persistent ischemic/functional MR late after surgical annuloplasty.

Papillary muscle dysfunction attenuates ischemic mitral regurgitation in patients with localized basal inferior left ventricular remodeling: insights from tissue Doppler strain imaging.

OBJECTIVES: The purpose of this research was to test whether papillary muscle (PM) dysfunction attenuates ischemic mitral regurgitation (MR) in patients with left ventricular (LV) remodeling of a similar location and extent. BACKGROUND: Papillary muscle dysfunction could attenuate tethering and MR because of PM elongation. However, variability in the associated LV remodeling, which exaggerates tethering, can influence the relationship between PM dysfunction and MR. METHODS: In 40 patients with a previous inferior myocardial infarction but without other lesions, the LV volume, sphericity, PM tethering distance, PM longitudinal systolic strain, and MR fraction were quantified by echocardiography. The patients were divided into two groups: group 1 with significant basal inferoposterior LV bulging but without advanced LV bulging involving other territories, therefore with a similar location and extent of LV remodeling, and group 2 without significant LV bulging. RESULTS: The medial PM tethering distance was significantly correlated with the %MR fraction (r2 = 0.64, p < 0.01), and multiple regression analysis identified an increase in the tethering distance as the only independent determinant of the MR fraction in all subjects and also in group 1. The PM longitudinal systolic strain had no significant relationships with MR fraction in all subjects with variable degrees of LV remodeling, but it had a significant inverse correlation with the MR fraction (r2 = 0.33, p < 0.01) in group 1 with LV remodeling of a similar location and extent, indicating that PM dysfunction is associated with less MR. CONCLUSIONS: Papillary muscle dysfunction, reducing its longitudinal contraction to induce leaflet tethering, attenuates ischemic MR in patients with basal inferior LV remodeling.

Relation of aneurysmectomy in patients with advanced left ventricular remodeling to postoperative left ventricular filling pressure, redilatation with ischemic mitral regurgitation.

Left ventricular (LV) volume, mitral E deceleration time, and mitral regurgitation (MR) fraction were measured by echocardiography in 14 patients with surgical LV aneurysmectomy. Late MR developed 3 to 6 months after surgery in 5 of the 14 patients (36%). Compared with patients without late MR, those with late MR had a significantly greater preoperative LV end-diastolic volume index (LVEDVI) (134 +/- 21 vs 93 +/- 19 ml/m(2), p <0.01), surgical reduction in LVEDVI (-51 +/- 14 vs -20 +/- 16 ml/m(2), p <0.01), early postoperative LV diastolic dysfunction with shortened mitral E deceleration time (106 +/- 23 vs 141 +/- 24 ms, p <0.01), and a late postoperative reincrease in LVEDVI (+28 +/- 4 vs +3 +/- 8 ml/m(2), p <0.01), suggesting that surgical LV aneurysmectomy in patients with advanced preoperative LV remodeling may result in postoperative LV diastolic dysfunction, promoting later LV redilation with ischemic MR.

Transient late-onset ischemic mitral regurgitation following Dor's procedure.

A 60-year-old man developed anteroseptal acute myocardial infarction with subsequent left hemiplegia. Echocardiography detected apical aneurysm with thrombus. Coronary artery bypass grafting with Dor's procedure were performed. Chronic heart failure (CHF) developed three months after the surgery. CHF with mitral regurgitation (MR) continued for more than two months and then disappeared. When surgical intervention is considered for late MR after Dor's procedure, it is important to consider that late-onset MR after Dor's procedure can be transient with full medication, which may require four or more months to achieve its full effects.

Left ventricular systolic function is abnormal in diastolic heart failure: re-assessment of systolic function using cardiac time interval analysis.

OBJECTIVES: The purpose of this study was to re-assess the left ventricular (LV) systolic function in diastolic heart failure (DHF) using Doppler echocardiography. BACKGROUND: Systolic function in DHF is defined as the preserved LV ejection fraction (EF). EF may not fully reflect the systolic function in DHF, especially in the presence of abnormalities during the isovolumetric contraction time (ICT). METHODS: We examined LV systolic and diastolic function in 80 consecutive patients with DHF, 30 patients with asymptomatic diastolic dysfunction (ADD), and 30 normal subjects (Control). The LV and left atrial volumes, LV EF, LV ICT, and isovolumetric relaxation time (IRT), early diastolic mitral flow velocity, systolic mitral annular velocity (S'), and early diastolic mitral annular velocity were obtained. RESULTS: LV ICT in DHF (69+/-30 ms) was significantly increased compared to those with ADD (37+/-23 ms) and Control (35+/-26 ms) (P<0.0001). ICT in ADD was equal to that in Control. The LV end-diastolic volume index in DHF (49+/-14 ml/m(2)) was significantly increased compared to those with ADD (42+/-12 ml/m(2)) and Control (43+/-8 ml/m(2)) (P<0.05). S' in DHF (5.9+/-1.4 cm/s) and ADD (6.7+/-1.1 cm/s) was significantly decreased compared to that in Control (8.7+/-2.5 cm/s). CONCLUSIONS: Our results revealed that the major differences between ADD and DHF were global and longitudinal LV systolic dysfunction and LV enlargement. This study suggests that LV systolic dysfunction plays an important role in the development of DHF.

Repeated waon therapy improves pulmonary hypertension during exercise in patients with severe chronic obstructive pulmonary disease.

OBJECTIVES: Repeated Waon therapy, which uses a far infrared-ray dry sauna system, improved the vascular endothelial function and the cardiac function in patients with chronic heart failure. In patients with chronic obstructive pulmonary disease (COPD), pulmonary hypertension (PH) is associated with a poor prognosis. We investigated whether repeated Waon therapy improves PH, cardiac function, exercise tolerance, and the quality of life (QOL) in patients with COPD. METHODS: Consecutive 13 patients with COPD, who met the Global Initiative for Chronic Obstructive Lung Disease criteria and had breathlessness despite receiving conventional treatments, were recruited for this study. They underwent Waon therapy at 60 degrees C in sauna for 15 min following 30 min warmth with blankets outside of the sauna room. This therapy was performed once a day, for 4 weeks. Cardiac function, exercise tolerance, and St. George's Respiratory Questionnaire (SGRQ) were assessed before and 4 weeks after Waon therapy. RESULTS: Right ventricular positive dP/dt at rest elevated significantly from 397 +/- 266 to 512 +/- 320 mmHg/s (p = 0.024) after the therapy. While the PH at rest did not significantly decrease, the PH during exercise decreased significantly from 64 +/- 18 to 51 +/- 13 mmHg (p = 0.028) after Waon therapy. Furthermore, the therapy prolonged the mean exercise time of the constant load of cycle ergometer exercise test from 360 +/- 107 to 392 +/- 97 s (p = 0.032). The total scores of SGRQ improved from 59.7 +/- 16.9 to 55.3 +/- 17.2 (p = 0.002). In addition, no adverse effects were observed related to Waon therapy. CONCLUSIONS: Repeated Waon therapy improved right ventricular positive dP/dt, PH during exercise, exercise tolerance and the QOL in patients with severe COPD.

Usefulness of a novel ultrasound transducer for continuous monitoring treadmill exercise echocardiography to assess coronary artery disease.

BACKGROUND: The feasibility of a novel ultrasound probe, which can be attached to the left ventricular (LV) apex chest wall and allows free rotation around its long axis direction for the continuous monitoring of LV wall motion, was tested. METHODS AND RESULTS: There were 36 subjects who had coronary artery disease (CAD). By attaching a novel ultrasound probe to the chest wall, the LV apical views were recorded during treadmill exercise stress echocardiography (Echo). The continuous monitoring of LV wall motion was satisfactorily feasible in 30 of 36 patients. The visualization rate of the overall LV segments was higher at rest (90%) compared to that during peak exercise (77%). The segments were better visualized in apical portions (90-100%) than in mid (77-96%) or basal portions (68-87%). The sensitivity, specificity, and accuracy for detecting CAD were 61, 100 and 77%, respectively. The wall motion score index 3 and 6 min after exercise decreased significantly compared to those at peak exercise. The number of segments with dyssynergy was highest at the peak exercise. Ischemic ST-T depression on electrocardiography was observed only at peak stress periods. CONCLUSIONS: Continuous monitoring treadmill exercise Echo using a novel ultrasound probe seems feasible for the non-invasive and physiological assessment of CAD.

Prediction of prognosis in the UM-X7.1 hamster model of congestive heart failure using the Tei index.

BACKGROUND: Cardiac function is difficult to evaluate in small animal models of heart disease. The Doppler Tei index is a simple and non-invasive measure that can express global cardiac function even in small animal models of congestive heart failure. However, its ability to predict prognosis has not been evaluated. METHODS AND RESULTS: We tested the hypothesis that cardiac functional indices, such as the Tei index, can predict the prognosis of hamsters with cardiac dysfunction. The Tei index, defined as the sum of the isovolume contraction and relaxation time divided by ejection time, and the percent fractional shortening of the left ventricle was measured in 48 anesthetized male hamsters (19.7+/-0.4 weeks old) with cardiac dysfunction (UM-X7.1), using Doppler and 2-dimensional echocardiography. The hamsters were separated into 2 groups based on the median Tei index (0.50) and % fractional shortening (FS) (21%). Kaplan-Meier analysis determined the survival rates of the groups. Both the Tei index and %FS enabled significant distinction of better and poorer survival (p < 0.01), and the survival curves were less overlapped when the animals were separated according to the Tei index. CONCLUSION: The Tei index can predict prognosis in a small animal model of heart failure.