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1.
OBJECTIVES

This study aimed to investigate prospectively the protective effect of a first preinfarction angina attack against acute myocardial infarction (AMI) in human hearts without significant collaterals.

BACKGROUND

Several retrospective studies and the prospective studies have demonstrated the existence of the preconditioning (PC) effect in humans. However, collaterals were not examined in the prospective studies. In animal models, the PC effect on myocardial infarct size appears soon after PC reperfusion (classic) but disappears within 1 to 2 h. It then reappears 24 to 48 h after reperfusion (the delayed PC effect). Meanwhile, the PC effect on stunning appears 12 h after PC reperfusion (the delayed PC effect). The concept of the classic and delayed PC effects has not been investigated in human AMI studies. If the above concept is also correct in humans, the infarct size and/or impairment of the left ventricular function should be inversely correlated with the time interval between the first preinfarction angina attack and the onset of AMI when that time interval is limited to between 2 and 48 h.

METHODS

The subjects were 25 patients with first AMI of the proximal left anterior descending artery who underwent successful direct percutaneous transluminal coronary angioplasty (PTCA) 2 to 6 h after the onset and with no (or poor) collateral circulation (grade 0 or 1). They were divided into two groups: preinfarction angina (PA)(+) group: 11 patients with new onset preinfarction angina from 2 to 48 h before the onset, PA(−) group: 14 patients without angina before infarction. Peak creatine kinase (CK) and cumulative CK were examined, and the left ventricular ejection fraction (LVEF) and the regional wall motion (RWM) were determined from the left ventriculograms during the acute (immediately after the coronary reperfusion) and chronic (four weeks after the onset of AMI) phases. The RWM index (RWMI) was then calculated as the mean motion of chords (standard deviation [SD]/chord) lying in the area of chords of RWM ≤ −2 SD in the acute phase (ischemic risk area).

RESULTS

The increase in the RWMI between the acute and chronic phases was significantly larger in the PA(+) group than in the PA(−) group (1.55 ± 1.32 and 0.69 ± 0.75, p < 0.05, respectively) although no significant difference in the enzymatic infarct size was seen between the two groups. The increases in the LVEF and the RWMI were significantly correlated with the time interval from the first preinfarction angina attack to the onset of AMI (r = 0.622, p < 0.05 and r = 0.646, p < 0.05, respectively), but the enzymatic infarct size was not.

CONCLUSIONS

The beneficial effect of preinfarction angina on left ventricular wall motion, independently of collateral flows, indicates the existence of the PC effect in humans. The greater protective effect of a longer time interval between angina pectoris and AMI suggests that the protection is due to a delayed PC effect.  相似文献   


2.
Objectives. This study sought to examine the mechanism of increasing coronary flow reserve after balloon angioplasty and stenting.

Background. Coronary vasodilatory reserve (CVR) does not improve after percutaneous transluminal coronary angioplasty in ≥50% of patients, postulated to be due to impaired microvascular circulation or inadequate lumen expansion despite adequate angiographic results.

Methods. To demonstrate the role of coronary lumen expansion, serial coronary flow velocity (0.014-in. Doppler guide wire) was measured in 42 patients before and after balloon angioplasty and again after stent placement. A subset (n = 17) also underwent intravascular ultrasound (IVUS) imaging of the target sites after angioplasty and stenting. CVR (velocity) was computed as the ratio of adenosine-induced maximal hyperemic to basal average peak velocity.

Results. The percent diameter stenosis decreased from (mean ± SD) 84 ± 13% to 37 ± 18% after angioplasty and to 8 ± 8% after stenting (both p < 0.05). CVR was minimally changed from 1.70 ± 0.79 at baseline to 1.89 ± 0.56 (p = NS) after angioplasty but increased to 2.49 ± 0.68 after stent placement (p < 0.01 vs. before and after angioplasty). IVUS lumen cross-sectional area was significantly larger after stenting than after angioplasty (8.39 ± 2.09 vs. 5.10 ± 2.03 mm2, p < 0.05). Anatomic variables were related to increasing coronary flow velocity reserve (CVR vs. IVUS lumen area: r = 0.47, p < 0.005; CVR vs. quantitative coronary angiographic percent area stenosis: r = 0.58, p < 0.0001).

Conclusions. In most cases, increases in CVR were associated with increases in coronary lumen cross-sectional area. These data suggest that impaired CVR after angioplasty is often related to the degree of residual narrowing, which at times may not be appreciated by angiography. A physiologically complemented approach to balloon angioplasty may improve procedural outcome.

(J Am Coll Cardiol 1997;29:1520–7)  相似文献   


3.
OBJECTIVES

The aim of this study was to evaluate the short-term effects of partial left ventriculectomy (PLV) on left ventricular (LV) pressure-volume (P-V) loops, wall stress, and the synchrony of LV segmental volume motions in patients with dilated cardiomyopathy.

BACKGROUND

Surgical LV volume reduction is under investigation as an alternative for, or bridge to, heart transplantation for patients with end-stage dilated cardiomyopathy.

METHODS

We measured P-V loops in eight patients with dilated cardiomyopathy before, during and two to five days after PLV. The conductance catheter technique was used to measure LV volume instantaneously.

RESULTS

The PLV reduced end-diastolic volume (EDV) acutely from 141 ± 27 to 68 ± 16 ml/m2 (p < 0.001) and to 65 ± 6 ml/m2 (p < 0.001) at two to five days postoperation (post-op). Cardiac index (CI) increased from 1.5 ± 0.5 to 2.6 ± 0.6 l/min/m2 (p < 0.002) and was 1.8 ± 0.3 l/min/m2 (NS) at two to five days post-op. The LV ejection fraction (EF) increased from 15 ± 8% to 35 ± 6% (p < 0.001) and to 26 ± 3% (p < 0.003) at two to five days post-op. Tau decreased from 54 ± 8 to 38 ± 6 ms (p < 0.05) and was 38 ± 5 ms (NS) at two to five days post-op. Peak wall stress decreased from 254 ± 85 to 157 ± 49 mm Hg (p < 0.001) and to 184 ± 40 mm Hg (p < 0.003) two to five days post-op. The synchrony of LV segmental volume changes increased from 68 ± 6% before PLV to 80 ± 7% after surgery (p < 0.01) and was 73 ± 4% (NS) at two to five days post-op. The LV synchrony index and CI showed a significant (p < 0.0001) correlation.

CONCLUSIONS

The acute decrease in LV volume in heart-failure patients following PLV resulted at short-term in unchanged SV, increases in LVEF, and decreases in peak wall stress. The increase in LV synchrony with PLV suggests that the transition to a more uniform LV contraction and relaxation pattern might be a rationale of the working mechanism of PLV.  相似文献   


4.
Objectives. The purpose of this study was to assess coronary flow characteristics in patients with chronic mitral regurgitation (MR).

Background. Coronary flow reserve (CFR) has been reported to be restricted in cases with left ventricular (LV) volume overload caused by aortic regurgitation and increased LV preload.

Methods. The study populations consisted of 31 patients with nonrheumatic chronic MR. Eleven with chest pain and normal coronary arteries served as control subjects. Phasic coronary flow velocities were obtained in the proximal segment of the angiographically normal left anterior descending coronary artery at rest and during hyperemia (0.14 mg/kg/min adenosine infusion intravenously) using a 0.014-in. (0.036 cm), 15-MHz Doppler guide wire. Coronary flow reserve was obtained from the ratio of hyperemic/baseline time-averaged peak velocity (APV). Thirteen cases who underwent mitral valve reconstructive surgery were also studied 1 month after surgery.

Results. Compared with control subjects, CFR was significantly reduced in cases with MR (2.1 ± 0.5 vs. 3.3 ± 0.6, respectively, p < 0.01) because baseline APV was significantly greater (28 ± 8 vs. 19 ± 6 cm/s, respectively, p < 0.01), although maximal hyperemic APV was not significantly different (56 ± 14 vs. 61 ± 16 cm/s, respectively, p = NS). Significant correlations were obtained between CFR and LV end-diastolic pressure (LVEDP) (r = 0.70, p < 0.01), LV mass index (r = 0.42, p < 0.01), LV end-diastolic volume (r = 0.38, p = 0.04) and MR volume (r = 0.39, p = 0.03), and stepwise regression analysis showed LVEDP was the most important determinant of CFR in MR (r2 = 0.49, p < 0.0001). This restricted CFR improved significantly after mitral valve reconstructive surgery (2.1 ± 0.5 vs. 3.1 ± 0.6, respectively, p < 0.01) because of reduction of baseline APV (28 ± 8 vs. 21 ± 8 cm/s, respectively, p < 0.01).

Conclusions. Coronary flow reserve is limited in cases with MR because of elevation of baseline resting flow velocity. This reduction of CFR correlates well with increase in LV preload, mass and volume overload, especially with increase in LV preload, and this restricted CFR improves after mitral valve surgery.  相似文献   


5.
Recent reports indicate that the coronary microcirculation is sometimes injured, despite successful reperfusion in acute myocardial infarction (AMI). However, it is difficult to evaluate the coronary microcirculation immediately after reperfusion by using only angiography. The purpose of this study was to examine the relationship between the pattern of coronary blood flow velocity and myocardial microcirculatory injury immediately after reperfusion in AMI. The authors recorded the left circumflex coronary flow velocity by using the Doppler guide wire method 10 minutes after reperfusion in a canine model of AMI. In addition, myocardial contrast echocardiography was performed with the injection of contrast medium into the left circumflex coronary artery before clamping of the coronary artery and 15 minutes after release of the clamp. From these images, the ratio of the normalized gray-level postreperfusion to preclamping in the contrast-enhanced area was determined. It was compared with coronary flow velocity variables. In the 10 dogs with a diastolic-to-systolic velocity ratio (DSVR) < 4.0, this velocity ratio 10 minutes after reperfusion correlated positively (r = 0.75, p < 0.01) with the normalized gray-level ratio. However, the remaining three dogs with a DSVR > or = 4.0 markedly deviated from this pattern. Coronary flow velocities in the three dogs were characterized by a greater decrease in systolic flow velocity and occurrence of early systolic retrograde flow. Myocardial contrast echocardiographic images in these three dogs demonstrated a lower normalized gray-level ratio. In conclusion, the coronary flow velocity pattern immediately after reperfusion may reflect myocardial microcirculatory injury.  相似文献   

6.
BACKGROUND: Experimental evidence indicates that magnesium sulfate may have potential cardioprotective properties as an adjunct to coronary reperfusion. The present study was designed to examine the hypothesis that magnesium might have beneficial effects on left ventricular (LV) function and coronary microvascular function in patients with acute myocardial infarction (AMI). METHODS AND RESULTS: The study population of 180 consecutive patients with a first AMI (anterior or inferior) underwent successful primary coronary intervention. Patients were randomized to treatment with either intravenous magnesium (magnesium group, n=89) or normal saline (control group, n=91). Pre-discharge left ventriculograms were used to assess LV ejection fraction (LVEF), regional wall motion (RWM) within the infarct-zone and LV end-diastolic volume index. The Doppler guidewire was used to assess coronary flow velocity reserve (CFVR) as an index of coronary microvascular function. Magnesium group subjects showed significantly better LV systolic function (LVEF 63+/-9% vs 55+/-13%, p<0.001; RWM: -1.01+/-1.29 SD/chord vs -1.65+/-1.11 SD/chord, p=0.004), significantly smaller LV end-diastolic volume index (63+/-17 ml/m(2) vs 76+/-20 ml/m(2), p<0.001), and significantly higher CFVR (2.95+/-0.76 vs 2.50+/-0.99, p=0.023) than controls. CONCLUSION: Magnesium sulfate as an adjunct to primary coronary intervention shows favorable functional outcomes in patients with AMI.  相似文献   

7.
OBJECTIVES

The goal of this study was to characterize detailed transmural left ventricular (LV) function at rest and during dobutamine stimulation in subendocardial and transmural experimental infarcts.

BACKGROUND

The relation between segmental LV function and the transmural extent of myocardial necrosis is complex. However, its detailed understanding is crucial for the diagnosis of myocardial viability as assessed by inotropic stimulation.

METHODS

Short-axis tagged magnetic resonance images were acquired at five to seven levels encompassing the LV from base to apex in seven dogs 2 days after a 90-min closed-chest left anterior descending coronary occlusion, followed by reflow. Myocardial strains were measured transmurally in the entire LV by harmonic phase imaging at rest and 5 ig.kg−1.min−1 dobutamine. Risk regions were assessed by radioactive microspheres, and the transmural extent of the infarct was assessed by 2,3,5 triphenyltetrazolium chloride staining.

RESULTS

Circumferential shortening (Ecc), radial thickening (Err) and maximal shortening at rest were greater in segments with subendocardial versus transmural infarcts, both in subepicardium (−1.1 ± 1.0 vs. 2.5 ± 0.6% for Ecc, −0.5 ± 1.9 vs. −1.8 ± 1.0% for Err, p < 0.05) and subendocardium (−2.0 ± 1.4 vs. 2.8 ± 0.8%, 2.4 ± 1.7 vs. 0.0 ± 0.9%, respectively, p < 0.05). Under inotropic stimulation, risk regions retained maximal contractile reserve. Recruitable deformation was found in outer layers of subendocardial infarcts (p < 0.01 for Ecc and Err) but also in inner layers (p < 0.01). Conversely, no contractile reserve was observed in segments with transmural infarcts.

CONCLUSIONS

Under dobutamine challenge, recruitment of myofiber shortening and thickening was observed in inner layers of segments with subendocardial infarcts. These results may have important clinical implications for the detection of myocardial viability.  相似文献   


8.
Do beta-adrenergic blocking agents increase coronary flow reserve?   总被引:5,自引:0,他引:5  
BACKGROUND

Beta-adrenergic blocking agents are the cornerstone in the treatment of coronary artery disease (CAD). The exact pathophysiologic mechanism is not clear but depends largely on the oxygen-sparing effect of the drug. Thus, the effect of metoprolol on coronary flow reserve and coronary flow velocity reserve (CFVR) was determined in patients with CAD.

METHODS

Coronary blood flow velocity was measured with the Doppler flow wire in 23 patients (age: 56 ± 10) undergoing percutaneous transluminal coronary angioplasty for therapeutic reasons. Measurements were carried out at rest, after 1-min vessel occlusion (postischemic CFVR) as well as after intracoronary adenosine (pharmacologic CFVR) before and after 5 mg intravenous metoprolol. In a subgroup (n = 15), absolute flow was measured from coronary flow velocity multiplied by coronary cross-sectional area.

RESULTS

Rate-pressure product decreased after metoprolol from 9.1 to 8.0 × 103 mm Hg/min (p < 0.001). Pharmacologic CFVR was 2.1 at rest and increased after metoprolol to 2.7 (p = 0.002). Likewise, postischemic CFVR increased from 2.6 to 3.3 (p < 0.001). Postischemic CFVR was significantly higher than pharmacologic CFVR before as well as after metoprolol. Coronary vascular resistance decreased after metoprolol from 3.4 ± 2.0 to 2.3 ± 0.7 mm Hg × s/cm (p < 0.02).

CONCLUSIONS

The following conclusions were drawn from this study. Metoprolol is associated with a significant increase in postischemic and pharmacologic CFVR. However, postischemic CFVR is significantly higher than pharmacologic CFVR. The increase in CFVR by metoprolol can be explained by a reduction in vascular resistance. The increase in CFVR (= increased supply) and the reduction in oxygen consumption (= decreased demand) after metoprolol explain the beneficial effect of this beta-blocker in patients with CAD.  相似文献   


9.
Objectives. In the present study, we examined post-stenotic coronary flow before and after percutaneous transluminal coronary angioplasty (PTCA) in patients with and without a recent myocardial infarction (MI) and related it to stenosis severity and residual viability.

Background. Post-stenotic coronary blood flow velocity reserve (CFVR) has been used with success to estimate functional stenosis severity in patients with stable angina. However, in patients with a recent MI, the impaired coronary vasodilator response of the reperfused myocardium may substantially alter the flow dynamics of the infarct-related artery.

Methods. Distal coronary flow velocities were recorded before and after PTCA in 36 patients at day 13 ± 7 (mean ± SD) after acute MI and in 38 patients without MI. The CFVR was assessed by the ratio of distal hyperemic to baseline average peak velocity, using a 0.014-in. Doppler guide wire. Stenosis severity was analyzed by quantitative coronary angiography, and infarct size was assessed scintigraphically.

Results. For similar angiographic stenosis severity, pre- and post-PTCA values of CFVR were significantly lower in patients with than without MI: 1.22 ± 0.26 versus 1.50 ± 0.45 before PTCA (p < 0.05) and 1.72 ± 0.43 versus 2.21 ± 0.74 after PTCA, respectively (p < 0.01). Although CFVR increased significantly (p < 0.0001) after angiographically successful PTCA in both study groups, abnormal CFVR (≤2.0) was still observed in 80% of patients with MI and in 44% of those without MI (MI vs. no MI, p = 0.001). Patients with an extensive infarction (relative infarct size ≥50%) and those with a small infarction (relative infarct size <50%) had comparable levels of post-PTCA CFVR (1.6 ± 0.3 vs. 1.8 ± 0.5, p = NS). Among a variety of factors, angiographic stenosis severity was the most important determinant of CFVR in both study groups.

Conclusions. In patients with a recent MI, CFVR was significantly lower than in those without MI, both before and after PTCA. Besides the presence of this postreperfusion-related impairment of the coronary vasodilating response, CFVR was mainly influenced by stenosis severity and not by residual viability.

(J Am Coll Cardiol 1996;28:1712–9)>  相似文献   


10.
OBJECTIVES

In a multicenter, randomized trial, systematic stenting using the Wiktor stent was compared to conventional balloon angioplasty with provisional stenting for the treatment of acute myocardial infarction (AMI).

BACKGROUND

Primary angioplasty in AMI is limited by in-hospital recurrent ischemia and a high restenosis rate.

METHODS

A total of 211 patients with AMI <12 h from symptom onset, with an occluded native coronary artery, were randomly assigned to systematic stenting (n = 101) or balloon angioplasty (n = 110). The primary end point was the binary six-month restenosis rate determined by core laboratory quantitative angiographic analysis.

RESULTS

Angiographic success (Thrombolysis in Myocardial Infarction [TIMI] flow grade 3 and residual diameter stenosis <50%) was achieved in 86% of the patients in the stent group and in 82.7% of those in the balloon angioplasty group (p = 0.5). Compared with the 3% cross-over in the stent group, cross-over to stenting was required in 36.4% of patients in the balloon angioplasty group (p = 0.0001). Six-month binary restenosis (≥50% residual stenosis) rates were 25.3% in the stent group and 39.6% in the balloon angioplasty group (p = 0.04). At six months, the event-free survival rates were 81.2% in the stent group and 72.7% in the balloon angioplasty group (p = 0.14), and the repeat revascularization rates were 16.8% and 26.4%, respectively (p = 0.1). At one year, the event-free survival rates were 80.2% in the stent group and 71.8% in the balloon angioplasty group (p = 0.16), and the repeat revascularization rates were 17.8% and 28.2%, respectively (p = 0.1).

CONCLUSIONS

In the setting of primary angioplasty for AMI, as compared with a strategy of conventional balloon angioplasty, systematic stenting using the Wiktor stent results in lower rates of angiographic restenosis.  相似文献   


11.
Objectives. This study was designed to determine the usefulness of transthoracic Doppler measurements in detecting increased left ventricular (LV) end-diastolic pressure in patients with coronary artery disease, specifically examining the influence of systolic function on the accuracy of these methods.

Background. Studies that have correlated Doppler indexes with LV filling pressures primarily involved patients with LV systolic dysfunction. The reliability of Doppler indexes in estimating filling pressures in patients with coronary artery disease and preserved systolic function is unclear.

Methods. Pulsed wave Doppler transmitral and pulmonary venous flow velocity curves and LV pressure were recorded in 83 patients with coronary artery disease.

Results. Conventional Doppler indexes (deceleration time of mitral E wave velocity, ratio of peak mitral E to A wave velocities and pulmonary venous systolic fraction) correlated with LV filling pressure in patients with an ejection fraction (EF) ≤50% but not in those with an EF >50%. Previously published regression analysis for prediction of LV filling pressure was accurate in patients with an EF ≤50% but not in those with an EF >50%. The difference between flow duration with atrial contraction in the pulmonary veins and transmitral flow duration with atrial contraction correlated with LV filling pressure in both groups.

Conclusions. Analysis of the early diastolic portion of the transmitral or pulmonary venous flow velocity curves can be used to predict LV filling pressures in patients with systolic dysfunction, but are inaccurate in patients with preserved systolic function. The combined analysis of both flow velocity curves at atrial contraction is a reliable, feasible predictor of increased LV filling pressure, irrespective of systolic function.  相似文献   


12.
Hemodynamic function and overall coronary blood flow (argon technique) were measured in 16 patients with idiopathic dilated cardiomyopathy (IDC) and in 12 patients without detectable heart disease (control subjects) referred for precordial pain. In patients with IDC, coronary blood flow was normal at rest (78 ± 17 ml/100 g·min versus 78 ± 9 in control subjects). During maximal inducible coronary vasodilation (dipyridamole, 0.5 mg/kg), coronary blood flow was significantly reduced (142 ± 38 ml/100 g · min versus 301 ± 64 in control subjects; p < 0.001). Consequently, obtainable minimal coronary resistance was increased in IDC (0.54 ± 0.20 mm Hg/ml/100 g · min versus 0.23 ± 0.04 in control subjects; p < 0.001). In patients with IDC, left ventricular (LV) end-diastolic pressure was significantly increased (19 ± 11 mm Hg versus 6 ± 3 in control subjects; p < 0.005), and the LV ejection fraction was diminished (36 ± 11% versus 72 ± 3% in control subjects; p < 0.001). In patients with IDC, LV end-diastolic pressure correlated significantly with the obtained minimal coronary resistance after application of dipyridamole (r = 0.85; p < 0.001). LV catheter biopsy specimens revealed no alterations in myocardial microvasculature. Thus, coronary dilatory capacity is impaired in patients with IDC, due partially to an increase in extravascular component of coronary resistance.  相似文献   

13.
OBJECTIVES

This study evaluated the acute physiological gain of adjunctive intravascular ultrasound (IVUS) guided balloon angioplasty and stent implantation.

BACKGROUND

Recent studies indicate safe coronary luminal enlargement and “stent-like” long-term outcomes using upsized balloons guided by IVUS.

METHODS

After angiographically guided balloon angioplasty in 20 patients with 1-vessel disease and normal left ventricular function, IVUS was performed to determine the size of the adjunctive balloon using the mean of the maximal luminal diameter and the maximal diameter of the external elastic membrane measured in the adjacent proximal and distal reference segments. Serial adenosine-induced hyperemic blood flow velocity measurements were performed using a 0.014″ Doppler guide wire to determine the physiological lumen obstruction after standard balloon angioplasty, followed by IVUS-guided balloon angioplasty and stent implantation.

RESULTS

Upsized balloon angioplasty (increase balloon size: 0.98 ± 0.26 mm; balloon:artery ratio 1.35 ± 0.21) resulted in an additional increase of arterial dimensions: minimal lumen diameter (MLD) 2.18 ± 0.38 mm to 2.73 ± 0.51 mm; percent diameter stenosis (%DS) 34 ± 13% to 19 ± 22%; IVUS assessed minimal lumen area (MLA) 7.53 ± 1.55 mm2 to 10.24 ± 2.22 mm2 (all p < 0.0001). Major dissections (≥ type C) did not occur. Hyperemic blood flow velocity increased from 49.8 ± 20.1 cm/s to 59.1 ± 22.9 cm/s (p < 0.05) after IVUS-guided balloon angioplasty. Adjunctive stent implantation resulted in a further increase of MLD to 3.84 ± 0.51 mm, %DS to −9 ± 21% and MLA to 13.39 ± 1.80 mm2 (all p < 0.0001), while hyperemic blood flow velocity remained unchanged (61.2 ± 24.7 cm/s, p = 0.7).

CONCLUSIONS

Upsized IVUS-guided balloon angioplasty increases arterial coronary dimensions and the distal hyperemic blood flow velocity. Adjunctive stent implantation does not yield a further gain in the hyperemic blood flow velocity, indicating the absence of a functional residual lumen obstruction after IVUS-guided balloon angioplasty. This may explain a similar clinical outcome reported after those coronary interventions.  相似文献   


14.
OBJECTIVES

The study was done to prospectively measure the echocardiographic, hemodynamic and clinical outcomes after partial left ventriculectomy (PLV).

BACKGROUND

Although PLV can improve symptoms of advanced heart failure, immediate postoperative echocardiographic findings remain abnormal.

METHODS

Fifty-nine patients with cardiomyopathy and advanced heart failure underwent PLV and concomitant mitral valve surgery between May 1996 and December 1997. Thirty-nine percent were on inotropic therapy. All were New York Heart Association (NYHA) functional class III or IV. Mechanical circulatory support (LVAD) and transplant were provided for rescue therapy when hemodynamic compromise occurred. Patients were followed for a mean of 405 ± 168 days, and clinical, echocardiographic and hemodynamic measures were obtained preoperatively, immediately postoperatively, and at 3 and 12 months prospectively.

RESULTS

Comparing preoperative and 12-month postoperative values in event-free survivors, we found: NYHA functional class improved from 3.6 to 2.1, p < 0.0001; peak oxygen consumption increased from 10.8 to 16.0 ml/kg/min, p < 0.0001; LV ejection fraction increased from 13 ± 6.0% to 24 ± 6.9%, p < 0.0001; LV end diastolic diameter decreased from 8.2 ± 1.03 to 6.2 ± 0.64 cm, p < 0.0001, and volume was reduced from 167 ± 60 to 105 ± 38 ml/m2, P = 0.02. Central hemodynamics did not normalize after surgery.

CONCLUSIONS

Partial left ventriculectomy can provide structural remodeling of the heart that may result in temporary improvement in clinical compensation. However, perioperative failures and the return of heart failure limit the propriety of this procedure.  相似文献   


15.
Objectives. We sought to examine the relation between regional changes in intramyocardial function and global left ventricular (LV) remodeling in the first 8 weeks after reperfused first anterior myocardial infarction (MI).

Background. Because of limitations in imaging methods used to date, this relation has not been thoroughly evaluated.

Methods. We studied 26 patients (21 men, 5 women; mean age 51 years) by magnetic resonance imaging (MRI) on day 5 ± 2 (mean ± SD) and week 8 ± 1 after their first anterior MI. All patients had single-vessel left anterior descending coronary artery disease and although they had received reperfusion therapy, all had regional LV dysfunction and an initial ejection fraction (EF) ≤50%. Short-axis magnetic resonance tagging was performed spanning the LV. Percent intramyocardial circumferential shortening (%S) on a topographic basis, LV mass index, LV end-diastolic volume index (LVEDVI), LV end-systolic volume index and LV ejection fraction (LVEF) were measured.

Results. Left ventricular mass index tended to decrease, whereas the LVEDVI increased from 82 ± 24 to 96 ± 27 ml/m2 (p = 0.002). Left ventricular end-systolic volume index remained unchanged, whereas LVEF increased from 39 ± 12% to 45 ± 14% (p = 0.002). Apical %S improved from 9 ± 6% to 13 ± 5% (p < 0.0001), as it did in the midanterior (6 ± 6% to 10 ± 7%, p < 0.02) and midseptal regions (8 ± 7% to 12 ± 6%, p < 0.02). Early dysfunction in remote midinferior and basal lateral regions resolved by 8 weeks. By multivariate analysis, the only significant predictor of an increase in LVEDVI over the study period was peak creatine kinase (p = 0.04).

Conclusions. In the first 8 weeks after a large, reperfused anterior MI, %S improved in the apex, midanterior and midseptal regions and normalized in remote noninfarct-related regions, but LV end-diastolic volumes also increased. This increased LVEDVI correlated with infarct size by peak creatine kinase and was not related to changes in global and regional LV function.  相似文献   


16.
Systemic and coronary hemodynamics and transmyocardial norepinephrine release were determined before and after oral administration of RO13-6438, a new inotrope-vasodilator agent, in 12 patients with severe chronic heart failure unresponsive to conventional and vasodilator therapy. improvement in left ventricular (LV) function was evident from a marked increase in cardiac index (from 2.09 ± 0.45 to 3.30 ± 0.73 liters/min/m2, p <0.01), stroke volume index (from 23 ± 7 to 36 ± 11 ml/m2, p <0.01), and stroke work index (from 23 ± 11 to 36 ± 14 g-m/m2, p <0.01), and concomitant fall in pulmonary capillary wedge pressure (from 26 ± 7 to 16 ± 8 mm Hg, p <0.01). Myocardial oxygen consumption did not change significantly (from 15.3 ± 6.8 to 14.9 ± 6.8 mi/min), but the ratio of minute work/myocardial oxygen consumption, an index of LV efficiency, Increased significantly (p <0.05). Although average coronary sinus flow did not change, coronary sinus oxygen increased (from 3.2 ± 0.8 to 4.2 ± 1.5 vol%, p <0.05), and arterial-coronary sinus oxygen difference decreased (from 11.8 ± 2.1 to 10.4 ± 1.9 vol%, p <0.05), suggesting a primary vasodilating effect of R013-6438 on the coronary vascular bed. Net transmyocardial norepinephrine release did not change despite the marked hemodynamic improvement. These findings suggest that R013-6438 has the potential to cause marked improvement in LV function and LV efficiency in patients with severe, refractory congestive heart failure.  相似文献   

17.
OBJECTIVES: The aim of this study was to evaluate the coronary blood flow velocity pattern immediately and 24 h after percutaneous transluminal coronary angioplasty (PTCA) for acute myocardial infarction (AMI) in relation to myocardial reperfusion and follow-up left ventricular (LV) function. BACKGROUND: Analysis of coronary blood flow velocity pattern after AMI may provide information about microvascular damage and the occurrence of a reperfusion injury. METHODS: Measurement of coronary blood flow velocity pattern was performed immediately after PTCA and after 24 h in 25 patients with first AMI using a Doppler guidewire. Measurements were related to reperfusion determined by intravenous myocardial contrast echocardiography (MCE) performed before PTCA and at 24 h and to LV function at four weeks. RESULTS: Using MCE, 13 patients showed reperfusion and 12 patients showed nonreperfusion. Compared with patients with reperfusion, patients with MCE nonreperfusion had a lower systolic peak flow velocity immediately after PTCA (10.0 +/- 0.3 cm/s vs. 19.3 +/- 0.8 cm/s, respectively) and after 24 h (12.3 +/- 0.4 cm/s vs. 21.3 +/- 0.1 cm/s, respectively, p = 0.0022), more frequent early systolic retrograde flow (6/12 vs. 0/13, p = 0.0052 immediately after PTCA and 24 h later) and a shorter diastolic deceleration time immediately after PTCA (483 +/- 6 ms vs. 737 +/- 0 ms, respectively) and after 24 h (551 +/- 9 ms vs. 823 +/- 2 ms, respectively, p = 0.0091). Similarly, patients with impaired LV function at four weeks had altered coronary flow pattern compared with patients with preserved function. The coronary flow velocity pattern showed a tendency for improvement after 24 h in the reperfusion and the nonreperfusion groups. CONCLUSIONS: The coronary flow velocity pattern immediately and 24 h after PTCA for AMI relates to myocardial perfusion determined by MCE and LV function at four weeks. The flow velocity pattern shows slight improvement during the first 24 h after revascularization, indicating the absence of a major reperfusion injury.  相似文献   

18.
OBJECTIVES

The purpose of this study was twofold: 1) to examine the relationship between menstrual cycle and coronary flow velocity reserve (CFVR) in young healthy women, and 2) to evaluate the effect of hormone replacement therapy by estrogen on CFVR in postmenopausal women, using transthoracic color Doppler echocardiography (TTCDE).

BACKGROUND

Although the incidence of cardiovascular disease is lower in women before menopause compared with men, postmenopausal women have an incidence of coronary artery disease similar to that of men of the same age. This is mainly dependent upon estrogen deficiency. However, no clinical report has yet examined the effect of estrogen on CFVR, which is one index of coronary microcirculation.

METHODS

We examined 15 male and both 15 premenopausal and 10 postmenopausal female healthy volunteers. We measured coronary flow velocity of the left anterior descending coronary artery at baseline and hyperemic conditions during adenosine triphosphate infusion by TTCDE and determined CFVR. Each premenopausal woman was studied two times (menstrual [M] and follicular [F] phases) in one menstrual cycle. Fifteen men were also studied at a time corresponding to women’s menstrual cycle. The postmenopausal women were studied before and two hours after oral administration of conjugated estrogen (CE).

RESULTS

Serum 17β-estradiol level in premenopausal women increased in the F phase and decreased to the same levels as in men, as in the M phase and as in postmenopausal women (123 ± 9 pg/ml vs. 28 ± 6 pg/ml, 25 ± 9 pg/ml and 19 ± 11 pg/ml; p < 0.0001, respectively). The CFVR increased in the F phase compared with that in the M phase (4.8 ± 0.4 vs. 3.7 ± 0.8, p < 0.0001). We found that CFVR in men remained unchanged (3.7 ± 0.6 vs. 3.8 ± 0.5). After CE administration, CFVR increased compared with baseline in postmenopausal women (4.1 ± 0.8 vs. 3.4 ± 0.8, p < 0.005).

CONCLUSIONS

In premenopausal women, CFVR determined by TTCDE varied during the menstrual cycle, and in postmenopausal women, CFVR increased after acute estrogen replacement.  相似文献   


19.
Direct coronary stenting without predilation   总被引:13,自引:0,他引:13  
OBJECTIVES

Coronary stenting is the primary therapeutic option for percutaneous treatment of many coronary lesions, after the risk of subacute stent thrombosis and bleeding complications has been reduced by improved antithrombotic regimens and high pressure stent expansion.

BACKGROUND

Direct stent implantation (without predilation) has been considered a promising new technique that may reduce the procedure time, radiation exposure time and cost.

METHODS

After having reviewed all cases of stent implantation from February to June 1998 (n = 585), 185 (32%) of these patients were retrospectively considered candidates for direct stent implantation without predilation, according to prespecified criteria (i.e., absence of severe coronary calcifications and/or tortuosity of the lesion or the segment proximal to the lesion). By operator preference, direct coronary stent implantation was actually attempted in 123 (21%) of the 585 patients (100 men, 60 ± 10 years old) on 123 lesions. The impact of direct stenting in terms of cost, procedure time, radiation exposure time and amount of contrast dye used was assessed by comparing the two groups of patients who underwent single-vessel stenting without (n = 69) and with (n = 46) predilation.

RESULTS

Direct stenting was successful in 118 patients (96%). No acute or subacute complications occurred in these patients. Procedure time, radiation exposure time and cost were significantly lower in the group of patients who had single-vessel direct versus conventional stenting (45 ± 31 vs. 64 ± 46 min, 12 ± 9 vs. 16 ± 10 min and 1,305 ± 363 vs. 2,210 ± 803 Euro, respectively; p < 0.05 for all).

CONCLUSIONS

Direct stenting without predilation in selected lesions seems to be a safe and successful procedure that provides a way to contain cost and to shorten radiation exposure time.  相似文献   


20.
BACKGROUND: Cilostazol, a phosphodiesterase inhibitor, is an antiplatelet agent with positive chronotropic effect, the impact of which on left ventricular (LV) volume and function in acute myocardial infarction (AMI) was evaluated in the present study. METHODS AND RESULTS: In 56 patients with AMI treated with primary coronary stenting, serial echocardiographic studies within 24 h and at 6 months were performed. Patients received a conventional antiplatelet regimen either without cilostazol (group 1, n=29) or with cilostazol (group 2, n=27). At 6 months, the difference in the change in heart rate between group 1 and group 2 was statistically significant (9.9 beats/min; p=0.04). However, changes in LV end-systolic volume (LVESV) (7.1+/-8.2 vs 10.0+/-21.7 ml, p=0.60), LV ejection fraction (EF) (8.2+/-9.9 vs 9.0+/-12.6%, p=0.85) and the ratio of early mitral inflow velocity to the mitral annular velocity (E/E') (0.6+/-3.7 vs -1.7+/-3.2) were not different between the 2 groups. Cardiac event rate was similar between the 2 groups. On multivariate regression analyses, cilostazol therapy had no significant influence on the changes in LVESV, LVEF or E/E'. CONCLUSIONS: In this study, the addition of cilostazol on conventional drug therapy had no adverse influence on LV remodeling or LV function after AMI.  相似文献   

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