In patients with an implanted DDD pacemaker (PM), the atrial contribution may be interrupted by too short an atrioventricular (AV) delay, and filling time may be shortened by too long an AV delay. The AV delay at which the end of the A wave on transmitral flow coincides with complete closure of the mitral valve may be optimal. The subjects were 15 patients [70.3+/-12.3 (SD) years old] with an implanted DDD PM. Cardiac output (CO) and pulmonary capillary wedge pressure (PCWP) were measured by Swan-Ganz catheter. Transmitral flow was recorded by pulsed Doppler echocardiography. AV delay was prolonged stepwise by 25 msc. When the AV delay was set at 155+/-26 ms, the end of the A wave coincided with complete closure of the mitral valve. When the AV delay was prolonged 25, 50, 75, and 100 ms from this AV delay, the interval between the end of the A wave and complete closure of mitral the valve was prolonged 16+/-5, 39+/-6, 65+/-4 and 88+/-5 ms, respectively (r = 0.97, P<0.0001) and diastolic mitral regurgitation was observed during this period. Thus, the optimal AV delay may be predicted as follows: the slightly prolonged AV delay minus the interval between the end of the A wave and complete closure of the mitral valve. When the AV delay was set at 215 ms, there was a significant positive correlation between the predicted optimal AV delay (166+/-23 ms) and the optimal AV delay (CO: 161+/-26 msec, r = 0.93, P<0.0001, PCWP: 161+/-28 msec, r = 0.95, P<0.0001). In conclusion, optimal AV delay can be predicted by this simple formula: slightly prolonged AV delay minus the interval between end of A wave and complete closure of mitral valve at the AV delay setting.
lthough success rates of percutaneous coronary intervention (PCI) are high, PCI of bifurcation lesions is associated with a relatively low success rate and a relatively high incidence of procedural complications, including side branch occlusion and myocardial infarction. . [1][2][3][4][5] Meier et al were among the first to identify the risk of side branch occlusion associated with parent vessel angioplasty. 1 They emphasized that side branches involved in vessel narrowing are at high risk for side branch occlusion during PCI. Boxt et al has reported that vessels with angiographic ostial stenosis >50% have a higher risk of occlusion than those without ostial stenosis. 2 Prior studies have demonstrated that intravascular ultrasound (IVUS) provides information not generated by angiography alone, and the use of sonographic measurements of vascular dimensions has improved short-and long-term outcomes. 6-10 Despite several lines of evidence suggesting that IVUS guidance can reduce the need for target lesion revascularization after PCI, 9,10 it remains controversial whether preintervention IVUS findings can help to identify side branches likely to occlude after PCI of bifurcation lesions.We examined whether preintervention IVUS provides information not available by angiography alone and if it can be used to predict side branch occlusion after PCI.
Circulation Journal Vol.69, March 2005
Methods
Lesions and the Patient PopulationThe study group consisted of 105 bifurcation lesions in 96 patients with coronary artery disease, all of which had undergone preintervention IVUS examination in the native coronary artery. No directional coronary atherectomy, rotational atherectomy, nor thrombectomy were performed. The clinical diagnoses included: acute myocardial infarction (AMI) (57%), stable angina pectoris (17%), unstable angina pectoris (15%), and previous myocardial infarction (11%). We studied bifurcation lesions involving the main branch and the ostium of the side branch. 11 Only side branches with an estimated reference luminal diameter of 1 mm or greater were considered. Twenty-four lesions were excluded for the following reasons: kissing balloon technique or sequential dilatation was performed (n=6) and extensive target lesion calcification or artifacts which precluded accurate cross-sectional evaluation of the vessel involved (n=18). The remaining 81 bifurcation lesions in 72 patients were studied.Side branch occlusion was defined as a thrombolysis in myocardial infarction (TIMI) flow of ≤2 by the final angiogram after PCI procedures. 12
Quantitative Coronary AngiographyAngiograms were reviewed before introduction of coronary guidewire and after balloon dilation or stent deployment. The coronary flow pattern of side branches was graded according to the classification system of the TIMI trial. 12 Angiograms were digitized and analyzed using an automated edge-detection algorithm (QCA-CMS, version 4.0, Medical Imaging Systems, Rotterdam, The Netherlands).
About three quarters of Japanese patients with ACS carried CYP2C19 variant alleles. The majority of IM and PM had increased platelet reactivity during the early phase of ACS. Although HTPR was frequently observed even 14-28 days after standard maintenance doses of clopidogrel in PM, the incidence of adverse outcomes did not differ, irrespective of CYP2C19 genotype.
Some surgical strategies can maintain or restore thoracic kyphosis (TK); however, next-generation surgical schemes for adolescent idiopathic scoliosis (AIS) should consider anatomical corrections. A four-dimensional correction could be actively achieved by curving the rod. Thus, anatomically designed rods have been developed as notch-free, pre-bent rods for easier anatomical reconstruction. This study aimed to compare the initial curve corrections obtained using notch-free rods and manually bent, notched rods for the anatomical reconstruction of thoracic AIS. Two consecutive series of 60 patients who underwent anatomical posterior correction for main thoracic AIS curves were prospectively followed up. After multilevel facetectomy, except for the lowest instrumented segment, either notch-free or notched rods were used. Patient demographic data, radiographic measurements, and sagittal rod angles were analyzed within 1 week after surgery. Patients with notch-free rods had significantly higher postoperative TK than patients with notched rods (P < .001), but both groups achieved three-dimensional spinal corrections and significantly increased postoperative rates of patients with T6–T8 TK apex (P = .006 for notch-free rods and P = .008 for notched rods). The rod deformation angle at the concave side was significantly lower in the notch-free rods than in the notched rods (P < .001). The notch-free, pre-bent rod can maintain its curvature, leading to better correction or maintenance of TK after anatomical spinal correction surgery than the conventional notched rod. These results suggest the potential benefits of anatomically designed notch-free, pre-bent rods over conventional, manually bent rods.
The use of distal embolic protection applied with a filter device decreased the incidence of the no-reflow phenomenon and was associated with fewer serious adverse cardiac events after revascularization than conventional PCI in patients with acute coronary syndromes with attenuated plaque ≥5 mm in length. (Assessment of Distal Protection Device in Patients at High Risk for Distal Embolism in Acute Coronary Syndrome [ACS] [VAMPIRE3]; NCT01460966).
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