Etsuo Yamaguchi

Redistribution in Thallium-201 Myocardial Imaging Soon After Successful Coronary Stenting

To evaluate the clinical significance of reversible perfusion defects that were observed soon after the successful deployment of a coronary stent, 47 patients underwent thallium-201 myocardial scintigraphy and radionuclide angiography in conjunction with adenosine-induced coronary hyperemia before and after complete revascularization. Coronary angiography showed a significant decrease in the percent diameter stenosis (from 87+/-11% before stenting to -1+/-5% after stenting, p<0.01) with no major dissection, residual stenosis, or intra-stent formation of thrombus. Even after the angiographically successful procedure, reversible perfusion defects were present in 17 (36%) of the 47 patients, none of whom showed any wall motion abnormalities during the infusion of adenosine. Disease duration was significantly longer and collateral vessels were more common in the patients with than in those without thallium redistribution, whereas the other clinical, pre- and post-stent angiographic and hemodynamic factors were similar. In conclusion, reversible perfusion defects without wall motion abnormalities were demonstrated during the infusion of adenosine in approximately one-third of patients soon after coronary stenting, and were not consistently related to acute unfavorable outcomes of stent placement.

Adequacy of Pacing Rate During Exercise in Rate Responsive Ventricular Pacing

Our objective was to determint; the adequate pacing rate during exercise in ventricular pacing by measuring exercise capacity, cardiac output, and sinus node activity. Eighteen patients with complete AV block and an implanted pacemaker underwent cardiopulmonary exercise tests under three randomized pacing rates: fixed rate pacing (VVJ) at 60 beats/min and ventricular rate‐responsive pacing (VVIR) programmed to attain a heart rate of about 110 beats/min ar 130 beats/min (VVIR 110 and VVIR 130, respectively) at the end of exercise. Compared with VVI and VVIR 130, VVIR 110 was associated with an increased peak oxygen uptake(VVIR 110:20.3 ± 4.5 vs VVI: 16.9 ± 3.1; P < 0.01; and VVIR 130: 19.0 ± 4.1 mL/min per kg, respectively; P < 0.05) and a higher oxygen uptake at anaerobic threshold (15.3 ± 2.7, 12.7 ± 1.9; P < 0.01, and 14.6 ± 2.6 mL/min per kg; P < 0.05). The atrial rate during exercise expressed as a percentage of the expected maximal heart rate was lower in VVIR 110 than in VVI or VVIR 130 (VVIR 110: 75.9%± 14.6% vs VVI: 90.6%± 12.8%; P < 0.01; VVIR 110 vs VVIR 130: 89.1%± 23.1%; P < 0.05). There was no significant difference in cardiac output at peak exercise between VVIR 110 and VVIR 130. We conclude that a pacing rate for submaximal exercise of 110 beats/min may be preferable to that of 130 beats/min in respect to exercise capacity and sympathetic nerve activity.

Eosinophilic myocarditis mimicking acute myocardial infarction with cardiogenic shock

心筋梗塞を思わせる心臓ショックで発症した,過好酸球増加症候群に伴う好酸球性心筋炎の早期に,心内膜心筋生検を行ない得たので報告する.症例は44才,女性. 3～4年前より気管支炎様症状あり.昭和58年6月,呼吸困難,全身の痛みにて入院.ショック症状,心筋逸脱酵素の上昇,心電図所見より,初め心筋梗塞を疑われたが, 6カ月前よりの好酸球増加および多彩な全身症状,発症3週後の右心室心内膜心筋生検での広範な心筋脱落と線維化および少数の好酸球浸潤,発症5週後の冠動脈造影像が正常なことより,好酸球性心筋炎と診断した. prednisolone投与により軽快し経過良好であるが,今後の推移については注意深く観察していきたい.