P2474Noninvasive estimation of pulmonary capillary wedge pressure by novel 3D speckle tracking echocardiography and validation study by cardiac catheterization

Background

We previously reported that pulmonary capillary wedge pressure (PCWP) was noninvasively evaluated by 2D speckle tracking echocardiography (STE). Recently, novel software was introduced to examine volume and function of left ventricular and left atrium (LA) by 3D-STE automatically.

Purpose

We sought to compare the PCWP estimated by conventional 2D-STE (2D-ePCWP) and by novel 3D-STE (3D-ePCWP), and validate those values by cardiac catheterization.

Methods

Echocardiography and catheterization were performed in 29 patients (age 72±2) (7 ischemic heart disease, 2 hypertensive heart disease, 5 dilated cardiomyopathy, 12 valvular heart disease and 3 primary pulmonary hypertension).The ePCWP (mmHg) is noninvasively obtained as 10.8 − 12.4 x Log (left atrial active emptying function/minimum volume) as we previously reported. Echocardiography was performed just before the catheterization and we analyzed the 2D and 3D data by novel off-line software. 3D data was automatically analyzed and the border settings were fixed at default (ES60, ED30) (Figure).

Results

2D-ePCWP and 3D-ePCWP had a good correlation with PCWP invasively obtained by catheterization (r=0.87 and 0.83, respectively, both p<0.001). There was an excellent correlation between 2D-ePCWP and 3D-ePCWP (r=0.94, p<0.001) and there was a good correlation between 2D-LA volume index and 3D- LA volume index (r=0.80, p<0.001). Bland-Altman analysis revealed a good agreement between 2D-ePCWP and 3D-ePCWP, and between 2D-ePCWP and 3D-ePCWP without fixed and proportional bias.

Conclusion

This study demonstrated that PCWP might be noninvasively assessed by not only 2D-STE but also 3D-STE with reasonable accuracy and 3D-STE might have utility and value in the routine clinical practice.

P4351Validation by cardiac catheterization of noninvasive evaluation of left ventricular chamber and myocardial stiffness as a diastolic function using speckle tracking echocardiography

Background

Left ventricular (LV) diastolic function is mainly composed of LV relaxation and LV stiffness. We reported that pulmonary capillary wedge pressure (ePCWP) and LV relaxation assessed by Tau (eTau) are noninvasively evaluated by speckle tracking echocardiography (STE). The minimum LV diastolic pressure (mLVP) was reported to have a strong correlation with Tau. Therefore, LV chamber stiffness (c-stiffness) may be assessed with the use of two LV diastolic pressure-volume coordinates: the mLVP and volume and the end-diastolic pressure (EDP) and volume.

Purpose

We sought to noninvasively assess LV stiffness using STE and validate the value by cardiac catheterization.

Methods

Echocardiography and catheterization were performed in 124 patients (age 72±8) (70 angina pectoris, 20 prior myocardial infarction, 19 hypertensive heart disease, 11 congestive heart failure and 4 paroxysmal atrial fibrillation). The ePCWP (mmHg) is noninvasively obtained as 10.8 − 12.4 × Log (left atrial active emptying function/minimum volume) and the eTau (ms) is obtained as isovolumic relaxation time/(ln 0.9 × systolic blood pressure − ln ePCWP) as previously reported. The mLVP (e-mLVP) was estimate using Tau. The estimated EDP (e-EDP) was calculated as 12.3 − 10.1 × Log (left atrial active emptying function / minimum volume). LV c-stiffness (mmHg/ml) was calculated as LV pressure change (from mLVP to EDP) obtained by catheterization divided by LV volume change during diastole which equals to stroke volume by echocardiography. Estimated c-stiffness (e-c-stiffness) was noninvasively obtained using e-mLVP and e-EDP. Furthermore, LV myocardial stiffness (m-stiffness) was calculated by LVED stress / LV longitudinal strain by STE, where LV stress (kdynes/cm2) was calculated as 0.334 × pressure × dimension / [thickness (1 + thickness/dimension)]. The estimated m-stiffness (e-m-stiffness) was calculated using e-EDP.

Results

The eTau and e-EDP estimated by STE had a good correlation with Tau and EDP invasively obtained by catheterization (r=0.75 and 0.63, respectively, both p<0.001). There was a good correlation between Tau and mLVP (Tau = 2.06 mLVP + 33.7, r=0.70). The estimated LVED stress had good correlation with ED stress obtained by catheterization (r=0.77, p<0.001). The e-c-stiffness and e-m-stiffness had a good correlation with those obtained by catheterization (e-c-stiffness; 0.116±0.07 and c-stiffness; 0.115±0.06, r=0.603, e-m-stiffness; 0.81±0.41 and m-stiffness; 0.85±0.45, r=0.89, respectively). Bland-Altman analysis revealed a good agreement between e-c-stiffness and c-stiffness, and between e-m-stiffness and m-stiffness without fixed and proportional bias.

Conclusion

This study demonstrated that LV stiffness may be noninvasively assessed by STE with reasonable accuracy and may have utility and value in the routine clinical practice for the diagnosis and treatment in patients with diastolic dysfunction.

Role of nitric oxide in nonadrenergic, noncholinergic relaxation of whole tracheal tube preparations isolated from guinea pigs

1. Frequency-dependent nonadrenergic, noncholinergic (NANC) relaxant responses were induced by transmural stimulation of whole tracheal tube preparations. 2. Responses at lower frequencies (< or = 10 Hz) were abolished by L-nitroarginine methyl ester (L-NAME). 3. Responses at higher frequencies (> or = 20 Hz) consisted of a rapid, short-lasting relaxation, followed by a slow, long-lasting relaxation. The former and the latter were reduced by L-NAME and alpha-chymotrypsin, respectively. 4. alpha-Chymotrypsin had little effect on the magnitude of NANC responses, but reduced the duration of responses at higher frequencies (> or = 20 Hz). 5. The results suggest that NANC relaxation of guinea pig trachea may be mediated primarily by nitric oxide, with and without concomitant release of vasoactive intestinal peptide or related peptides, and nitric oxide may act as predominant mediator providing the magnitude of relaxant response.

Identification of asynergic but viable myocardium in patients with chronic coronary artery disease by gated blood pool scintigraphy during isosorbide dinitrate and low-dose dobutamine infusion: comparison with thallium-201 scintigraphy with reinjection

To evaluate the ability of low-dose dobutamine and isosorbite dinitrate (ISDN) gated blood pool scintigraphy (GBPS) and thallium SPECT with reinjection to identify viability in asynergic myocardium, both procedures were performed in 38 consecutive patients with chronic coronary artery disease and left ventricular dysfunction. Twenty-two of the 38 patients with successful revascularization were analyzed. GBPS was performed at the baseline and during continuous infusion of low dose dobutamine (5 micrograms/kg/min) and ISDN (2 micrograms/kg/min). Cine mode GBPS wall motion was scored from normal (0) to dyskinesis (4) semiquantitatively. Forty-seven of 110 segments with severe asynergy at the baseline were analyzed. Viability determined by GBPS was defined as wall motion score improvement by more than 1 grade. Thallium viability was defined as the segment with redistribution or fill in with severe initial perfusion defect. GBPS was 76.7% sensitive and 70.6% specific for predicting post vascularization wall motion improvement (p < 0.005). Of 47 segments with severe asynergy, concordance of judgement was obtained in 40 segments (85.1%), and reversibility was correctly diagnosed in 34 of 40 patients (85.0%), but thallium with reinjection correctly identified tissue viability in 6 of 7 segments with discordance between 2 studies. These data suggest that most cases of reversible asynergy (hibernating myocardium) respond to ISDN and dobutamine, suggesting the possibility of predicting improvement by revascularization, although some underestimation of tissue viability remained to be resolved. Thallium with reinjection is superior to low-dose dobutamine + ISDN GBPS for the assessment of myocardial viability.

Effects of 3 aminoglycoside antibiotics (kanamycin, gentamicin and fradiomycin) on the thrombin-induced aggregation and intracellular Ca2+ mobilization of human platelets

This study was aimed at determining whether the thrombin (TRB)-induced aggregation and intracellular free Ca2+ ([Ca(2+)]i) mobilization of fura-2-loaded human platelets would be affected by aminoglycoside antibiotics (AGs), i.e., kanamycin (KM), gentamicin (GM) and fradiomycin (FRM) with 4, 5 and 6 amino groups in their molecules, respectively. We used pH-adjusted solution of AGs, since the TRB-induced aggregation and [Ca(2+)]i mobilization are pH-dependent. TRB (0.1 U/ml) induced aggregation in the presence of 1 mM external Ca2+ but did not in the absence of external Ca2+. The 3 AGs reduced the TRB-induced aggregation and the antiaggregating potencies were in the order FRM = GM > KM. TRB-induced [Ca(2+)]i elevation in the presence of external Ca2+ was 3 times higher than in the absence of external Ca2+ and the 3 AGs concentration-dependently reduced the TRB-induced [Ca(2+)]i elevation in the absence of external Ca2+ as well as in its presence, and the potency order was FRM > GM > KM. The IC50 of GM or KM was higher in the absence of external Ca2+ than in its presence, while the IC50 of FRM was scarcely affected by the deprivation of external Ca2+. These results suggest that the reducing potency of the 3 AGs in the TRB-induced aggregation and [Ca(2+)]i mobilization of human platelets is based on the number of amino groups. Furthermore, it is suggested that GM and KM predominantly reduce the Ca2+ influx rather than the intracellular Ca2+ release but FRM is equieffective in decreasing both of them.

[Perfusion imaging with 99mTc PPN-1011 for the assessment of myocardial area at risk and the efficacy of PTCA/PTCR in myocardial infarction and unstable angina]

The determination of the myocardium at risk before intervention and the change in that region after intervention constitute a promising measurement tool for the assessment of acute therapy. We used 99mTc PPN-1011 in 4 patients with acute myocardial ischemia (2 patients with acute myocardial infarction, 2 unstable angina) and subsequent successful reperfusion. All 4 patients had perfusion defect on the pre-reperfusion image. Perfusion abnormality on post-reperfusion image was all improved significantly compared with pre-reperfusion image, suggesting the efficacy of acute treatment in acute myocardial ischemia. We conclude that 99mTc PPN-1011 scintigraphy is useful method for the assessment of myocardial area at risk and the efficacy of PTCA/PTCR in myocardial infarction and unstable angina.

[Suppressive effect of sialic acid on the prostaglandin E2-mediated edema in carrageenin-induced inflammation of rat hind paws]

We performed these studies to determine whether sialic acid (SIA) existed in the inflammatory exudate of the carrageenin (Car)-air pouch model and to elucidate the mechanisms of the antiinflammatory action of SIA on the Car-induced edema in rat hind paws. SIA (113.20 +/- 10.73 micrograms/ml) was detected in the exudate of Car-air pouch, and the plasma SIA (660.29 +/- 29.38 micrograms/ml) in Car-air pouch rats was significantly higher than that (490.00 +/- 29.37 micrograms/ml) in control rats. SIA (300 mg/kg, s.c.) suppressed the delayed phase of Car-induced edema, and it also suppressed the edema induced by Car plus arachidonic acid, Car plus PGE2, and bradykinin plus PGE2. However, SIA did not affect the edema induced by dextran, histamine, bradykinin, and Car plus PGE1. SIA affected neither the PG production in rats nor the [3H]PGE2-receptor binding of guinea pig ileum, and SIA reduced the PGE2-induced contraction of isolated guinea pig ileum. The above results suggest that SIA induces the antiinflammatory effects via its antagonism against PGE2. Furthermore, the presence of SIA in the inflammatory exudate and the higher concentration of SIA in the plasma than in the exudate might suggest that SIA plays patho-physiologically protective roles in inflammatory states.