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冠動脈複雑性病変に対するcoronary rotational atherectomy (RA)は有効な血行再建術の一つとして普及しつつあるが, 治療効果等に関しては報告が少ない.今回われわれはRAの初期成績および遠隔期成績について検討した.1997年12月～2000年4月の間に当院でRAを施行した連続30例, 32病変を対象とした.RA後バルーンカテーテルによる低圧拡張の追加を基本方針とし, 必要に応じて高圧拡張・ステント留置を行った.残存狭窄50%未満かつTIMI3をもって手技成功とし, 遠隔期(3～6カ月後)造影所見における50%以上の狭窄を再狭窄とした.標的病変は全てが高度石灰化を伴う複雑性病変(タイプB2病変が22病変(69%), タイプC病変が10病変(31%))であった.手技成功は28病変(87.5%)に得られ, 平均径狭窄率は78±9%から20±14%に改善した.手技不成功の原因としてはガイドワイヤー不通過, プラットホーム形成困難等であり, RAが施行可能であった28病変はすべて手技成功が得られた.遠隔期に17病変において冠動脈造影を施行し, 再狭窄を8例(47%)に認め, 平均径狭窄率は52±25%であった.再狭窄を認めた全例に再血行再建(RA1例・ステント留置7例)を施行したが, RAによるlesion modificationによって, RA以外の手技にて良好な初期成功率が得られた.再狭窄率は低くないが, 慎重な症例選択と手技を行えば, RAは石灰化を有する複雑性病変に対し, 粥腫の切除(debulking)のみでなくlesion modificationの面でも有用な治療手技であると考えられた.

Acute coronary syndrome(ACS) and acute aortic dissection(AAD) are life-threatening conditions which can be difficult to differentiate in the emergency room because of the similarity of clinical presentations. In addition, ACS can be caused in AAD as a complication of the dissecting process. Usual form of ACS is caused by an obstruction of the epicardial coronary arteries, which is initiated with the rupture of an unstable atherosclerotic plaque complicated with subsequent thrombus formation(Libby , 2001). On the other hand, ACS secondary to AAD is caused by malperfusion of the coronary artery by an obstruction of the orifice as a complication of the dissecting process. If AAD is compicated with ACS, prognosis becomes worse and the treatment of choice may be totally different from usual ACS. Medications and procedures which are usually used in cases of ordinary ACS, such as Heparin, antiplatelets, thrombolytic agents and catheter interventions, may be harmful in ACS secondary to AAD. So it is of great importance to make a correct diagnosis of ACS secondary to AAD for better treatment and survival.

To evaluate the effectiveness of distal protection with the GuardWire Plus during primary angioplasty in patients with acute myocardial infarction.Thirty-eight consecutive patients undergoing stent implantation with distal protection using the GuardWire Plus (DP-group) were compared with a matched control group undergoing conventional stent implantation after balloon angioplasty without distal protection (NDP-group). Microvascular circulation after revascularization was assessed by Thrombolysis in Myocardial Infarction (TIMI) flow grade, myocardial blush grade (MBG), serum creatine kinase peak release, and ST resolution. Left ventricular ejection fraction was measured by echocardiography at discharge. Follow-up quantitative coronary angiography and left ventriculography were performed 6 months after percutaneous coronary intervention. Quantitative coronary angiography data, restenosis rate, target lesion revascularization rate and follow-up left ventricular ejection fraction were also compared between the two groups.No significant differences were observed in baseline clinical and angiographic characteristics between the two groups. The TIMI flow grade 3 (DP-group 81.6% vs NDP-group 57.9%)and MBG 3 (57.9% vs 30.6%)were significantly greater in the DP-group respectively (p0.05). Post procedural ST-segment resolutionor = 50% was found in a significantly higher percentage of patients in the DP-group (68.4% vs 42.1%, p0.05). Left ventricular ejection fraction at discharge was significantly greater in the DP-group (55.5 +/- 8.5% vs 45.7 +/- 11.1%, p0.05). However, 6 months after the percutaneous coronary intervention, no significant difference was observed between the two groups. Restenosis rate and target lesion revascularization rate were similar in the two groups.Distal protection with the GuardWire Plus improved the microvascular circulation as assessed by TIMI flow grade, MBG, and ST resolution. Furthermore, left ventricular ejection fraction at discharge was improved.

Subtle variations in QRS morphology occurs during idiopathic outflow tract ventricular tachycardia (OTVT), but no studies have clarified the prevalence and characteristics of the OTVT with altered QRS morphology following radiofrequency catheter ablation (RFA), which then require an additional RF application at a different portion of the outflow tract to abolish OTVT. Of 202 patients with a monomorphic VT or premature ventricular contraction (PVC) originating from the outflow tract, 6 (3%) showed changes in QRS morphology in the OTVT following RFA, requiring an additional RF application to the outflow tract at a different portion. In all six patients, RFA was applied for the first or second OTVT to a right or left ventricular endocardial site, with the other site being the left sinus of Valsalva. In each patient, OTVT before or after the changes in QRS morphology had characteristic ECG findings originating from a particular portion of the outflow tract. Changes in QRS morphology consistently included an increase or decrease in R wave amplitude in all inferior leads. Detailed continuous observation of QRS morphology in OTVT, especially R wave amplitude in inferior leads, is important for identifying changes of QRS morphology during catheter ablation. Mapping and ablation at a different portion of the outflow tract is then needed for cure.

Cardiac resynchronization therapy (CRT) is widely known to improve cardiac function in patients with chronic heart failure, especially those with increased intraventricular conduction delay. However, whether vascular endothelial cell function is improved remains unknown. Capability of nitric oxide (NO) production is a good marker to evaluate endothelial cell function. Therefore, NO output was measured in exhaled air in patients with chronic heart failure after CRT.Six patients with chronic heart failure and dilated cardiomyopathy (mean age 62.0 +/- 11.3 years, left ventricular ejection fraction 22.8 +/- 11.6%) received CRT. Pacing leads were lodged at the right atrium, the apex of the right ventricle and at the mid portion of the postero-lateral branch of the coronary sinus. One month after CRT, endtidal NO concentration was evaluated with and without pacing using the chemiluminescence method.Left ventricular ejection fraction improved from 22.8% to 28.8% after the procedure. Endtidal NO was significantly (p = 0.038) increased from 64.7-13.2 ppb without pacing to 69.1-14.1 ppb with pacing. Respiratory rate (with pacing: 19.7-5.7 n/min, without pacing: 20.3-4.8 n/min), tidal volume (with pacing: 523.2-122.7 ml, without pacing: 516.2-160.3 ml) and minute ventilation were not changed.CRT did not affect respiratory rate, tidal volume or minute ventilation, so increased endtidal NO did not result from enhanced production from tracheal and/or bronchial epithelial cells. Therefore, endtidal NO increased because chronic heart failure increased pulmonary perfusion and so raised vascular shear stress. CRT for patients with dilated cardiomyopathy can improve vascular endothelial cell function.

An 83-year-old woman presented with dilated cardiomyopathy. Cardiac resynchronization therapy was performed. Two weeks later, cardiac output and ventricular wall motion were estimated using impedance cardiography and tissue Doppler echocardiography with and without pacing. Cardiac output increased from 3.5 to 4.5 l/min during biventricular pacing with a 120 msec atrioventricular interval. Intraventricular phase difference for contraction decreased from 190 to 150 msec. When the atrioventricular interval was 180 msec, cardiac output and phase difference became 4.6 l/min and 170 msec. These assessments were performed rapidly and non-invasively. New impedance cardiography and tissue Doppler echocardiography are useful to evaluate the effect of cardiac resynchronization therapy.

This study evaluated the long-term outcomes of successfully implanted S670 and NIR stents.Stents were successfully implanted in 143 patients (148 lesions) aged 65 +/- 9 years from January 1999 to April 2001. Sixty-eight lesions were treated with S670 stents and 80 with NIR stents. Quantitative coronary angiography was performed before, immediately after and 6 months after implantation. An angiographic classification of in-stent restenosis was developed according to the geographic distribution of intimal hyperplasia in reference to the implanted stent. Furthermore, the relationships between stent diameter and length and restenosis rate were estimated.Type B2/C lesions were significantly more common in patients with S 670 (77.3%) stents compared with NIR (43.6%). Stent length was longer and diameter was smaller in patients with S 670 stents compared with those with NIR stents. Acute-gain was similar in the two groups, but late-loss was significantly greater in patients with S 670 stents compared with those with NIR stents. Restenosis rate and target lesion revascularization rate were similar in the two groups. The diffuse type of restenosis lesion was frequently found in S 670 stents. The stent diameter, but not stent length, influenced the restenosis rate in S 670 stents. Both stent length and diameter influenced the restenosis rate in NIR stents.Late-loss was larger and in-stent restenosis of diffuse type was significantly greater in S 670 stents compared with NIR stents. However, stent length was significantly longer and type B2/C lesions were significantly greater in S 670 stents compared with NIR stents. There was no difference in restenosis rate and target lesion revascularization rate. In addition, restenosis rate was not influenced by stent length in S 670 stents, so S 670 stents may be useful for complex lesions.