Tsutomu Miida

Additional ST-segment elevation immediately after reperfusion and its effect on myocardial salvage in anterior wall acute myocardial infarction

Rapid resolution of ST-segment elevation is a reperfusion-associated electrocardiographic change in acute myocardial infarction. However, some patients have additional ST-segment elevation immediately after reperfusion before such resolution. The clinical significance and the effect on myocardial salvage of this electrocardiographic change are unknown. To examine this electrocardiographic feature and determine its clinical basis for occurrence and influence on left ventricular function, 58 consecutive patients with a first anterior wall acute myocardial infarction who had intracoronary thrombolysis or coronary angioplasty, or both, were assessed. With the use of frequent electrocardiographic procedures during reperfusion therapy, patients were divided in 2 groups: those with additional ST-segment elevation (n = 35; group A, > or = 0.5 mV increase in summed ST-segment elevation in lead V1-V6 within 15 minutes after reperfusion), and those without this phenomenon (n = 23; group B). Baseline characteristics, creatine kinase kinetics and left ventricular function were compared between both groups. Before reperfusion, group A had a greater summed ST-segment elevation (2.44 +/- 1.07 vs 1.57 +/- 0.98 mV; p = 0.003) and poorer collaterals (p = 0.001) than did group B. Peak creatine kinase was significantly higher in group A than in B (6,550 +/- 3,477 vs 4,310 +/- 1,880 IU/liter; p = 0.003). Group A had less improvement in ejection fraction (-4.2 +/- 9.9% vs 1.7 +/- 9.6%; p = 0.04) and regional wall motion (0.28 +/- 0.74 vs 0.76 +/- 0.79 SD/chord; p = 0.03) than did group B. It is thought that additional ST-segment elevation immediately after reperfusion occurred in myocardium with severe ischemic damage before reperfusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Guidewire-induced coronary artery perforation treated with transcatheter delivery of subcutaneous tissue.

In three cases of small coronary artery perforation by guidewires during percutaneous coronary intervention, coronary leakage continued despite prolonged balloon inflation and reversal of heparin. Subcutaneous tissue was selectively delivered to perforated vessels by means of microcatheters in a successful attempt to stop leakage. This method appears to be extremely effective for treating guidewire‐induced perforations of distal coronary arteries.

Immediate effects of percutaneous transvenous mitral commissurotomy on pulmonary hemodynamics at rest and during exercise in mitral stenosis

Hemodynamics were evaluated during exercise in 33 patients with mitral stenosis who underwent percutaneous transvenous mitral commissurotomy (PTMC). PTMC was performed using an Inoue balloon. Each patient underwent a supine ergometer exercise test before and on the day after PTMC. Ergometer work load was started at 20 W and increased in increments of 20 W at 3-minute intervals until terminated by the patients fatigue or shortness of breath. Mitral valve area increased by 0.8 +/- 0.4 cm2 (1.1 +/- 0.3 to 1.9 +/- 0.4 cm2, p less than 0.001). Mean mitral pressure gradient decreased (12 +/- 5 to 6 +/- 2 mm Hg, p less than 0.001). Pulmonary arterial pressure significantly decreased and the cardiac index significantly increased both at rest and during exercise after PTMC. Before PTMC, the increases in pulmonary arterial pressure, total pulmonary resistance and pulmonary arteriolar resistance during exercise were greater in patients with a mitral valve area less than 1.0 cm2 than in patients with an area greater than or equal to 1.0 cm2. After PTMC, total pulmonary resistance still increased during exercise. However, pulmonary arteriolar resistance did not change during exercise in patients with a mitral valve area greater than or equal to 1.5 cm2, whereas it increased in patients with an area less than 1.5 cm2. An enlarged mitral valve area greater than or equal to 1.5 cm2, which may prevent pulmonary vasoconstriction and permits a greater increase in pulmonary blood flow during exercise, is considered a good result immediately after PTMC.

Exercise Induced Atrioventricular Block with Gap Phenomenon in Atrioventricular Conduction

A 54‐year‐old man with normal atrioventricuiar (AV) conduction at rest gave a 4‐year history of presyncope during exercise. Treadmill testing showed exercise induced AV block. Electrophysiological study demonstrated rate dependent infranodal AV block and abnormal refractory period of the His‐Purkinje system. The gap phenomenon in AV conduction occurred during the programmed stimulation. Supernormal conduction could be considered as the mechanism of the gap phenomenon in this patient.

Coronary vasospasm triggered ventricular fibrillation delayed after radiofrequency ablation of the right accessory pathway.

Ventricular fibrillation associated with coronary vasospasm developed 8 h after successful radiofrequency (RF) ablation of the right accessory pathway in an 81-year-old male. A segment of the coronary vasospasm was located close to the accessory pathway, where seven RF ablations had been applied. Although rare, physicians should carefully consider the risk of such events when an RF current is applied near a coronary artery.

Improved cardiac function after sirolimus-eluting stent placement in diabetic patients by pioglitazone: Combination therapy with statin

BACKGROUND Peroxisome proliferator-activated receptor-gamma (PPAR-gamma) agonists are used as anti-diabetic drugs, and their pleiotrophic action has been reported to improve endothelial function leading to cardioprotective effects. In this study we evaluated the long-term effect of pioglitazone on cardiac function in diabetic patients after percutaneous coronary intervention (PCI) by drug-eluting stent (DES). METHODS AND RESULTS We investigated 54 diabetic patients who received PCI using a sirolimus-eluting stent. We excluded cases of acute myocardial infarction. They were divided into two groups: Group C received only conventional therapy (n=26) and Group P received additionally pioglitazone 15 mg/day (n=28). The left ventricular ejection fraction (LVEF) was measured by left ventriculography and analyzed before and 8 months after PCI. In Group C, LVEF did not change significantly: 55.6% vs. 56.7%, before and after PCI respectively (p=0.58). However, pioglitazone significantly improved LVEF: 54.4% vs. 60.0% (p=0.014). Multiple linear regression analysis showed that DeltaLVEF was significantly related to pioglitazone therapy (p=0.037). In particular, the combination of pioglitazone and statin improved LVEF (DeltaLVEF 9.6% with vs. 2.2% without statin). CONCLUSIONS Pioglitazone improved cardiac function after PCI using SES in diabetic patients, especially in combination with a statin.

Assessment of a coronary artery fistula to the pulmonary artery by transesophageal echocardiography

ninen E, LInsimies E, Uusitupa M. Noninvasive detection of cardiac sympathetic nervous dysfunction in diabetes using ‘%metaiodobenzylguanidine. Diabetes 1992;41:1069 75. Mustonen J, Mlntysaari M, Kuikka J, Vanninen E, Vainio P. LBnsimies E, Uusitupa M. Decreased myocardial lz31-metaiodobenzylguanidine uptake is associated with disturbed left ventricular diastolic filling in diabetes. Ah/l HEART J 1992;123:804-5. Murakawa Y, Inoue H, Nozaki A, Sugimoto T. Role of sympathovagal interaction in diurnal variation of QT interval. Am J Cardiol 1992;69:339-43.

Two-wire protection of side branches to prevent side branch occlusion during stent implantation for bifurcational lesions

To prevent side branch occlusion during bifurcational lesion stenting, the placement of a wire in both the main branch and side branch is performed for “side-branch protection”. However, this procedure does not always prevent side branch occlusion. A procedure for placing two wires in the side branch, called “two-wire protection of side branches”, is considered to be more likely to prevent occlusion compared with one-wire protection of the side branch. We report on three cases in which “two-wire protection of side branches” was effectively performed during the stenting of bifurcational lesions.

Efficacy of Marker Wire for intracoronary stenting

The Marker Wire was used for Palmaz-Schatz coronary stent implantation. The Marker Wire is useful in estimating lesion length and in determining the number of stents required, in addition to facilitating stent positioning.

Manifestation of latent left ventricular outflow tract obstruction caused by acute myocardial infarction: An important complication of acute myocardial infarction

BACKGROUND Although transient left ventricular outflow tract (LVOT) obstruction is reported as a complication with acute myocardial infarction (AMI), the mechanisms and features of LVOT obstruction in AMI are unclear. METHODS AND RESULTS Herein, we present two cases of transient LVOT obstruction with anteroseptal AMI. The features of these two cases were one-vessel disease (1-VD) of the left anterior descending artery (LAD) and maintenance of blood flow to the major septal branch (SB). Moreover, LVOT obstruction was revealed after dobutamine infusion in the chronic phase and the aorto-septal angle was low in these two cases, meaning that latent LVOT obstruction was due to sigmoid-shaped septum. CONCLUSIONS Latent LVOT obstruction would be manifested in the acute phase of AMI. 1-VD of LAD and the maintenance of major SB blood flow are important factors with respect to the manifestation of latent LVOT obstruction.