New method for placement of intracoronary stents in order to avoid their embolization in the intravascular space.

Stent dislodgment from the delivery catheter is a well-known complication of angioplasty with stent implantation. The aim of our study was to investigate the feasibility, effectiveness, and safety of a new technique of intracoronary stent implantation in order to avoid stent loss in the intravascular space. Fifty consecutive patients were candidates for angioplasty and stent placement. During angioplasty, a technique was followed according to which the guide wire "hindered" the dislodgment of the stent from the balloon catheter. Successful angioplasty and stent placement were performed in 46 out of 50 patients (92% success rate). In three cases of failure of stent implantation, the stent moved onto the balloon catheter; however, this was impeded by the guide wire. One non-Q-wave myocardial infarction occurred. No major complications (Q-wave myocardial infarction, CABG, or death) were observed. In conclusion, the technique applied was feasible enough, safe, and effective. However, the appropriate modification of its "hardware" will render it even more feasible and user-friendly.

Posterior right diagonal artery. An angiographic study.

The purpose of this prospectively performed study was the angiographic visualization of the posterior right diagonal artery (PRDA) and its differentiation from the epicardial branches of the right coronary artery (RCA), that is, the right marginal artery and the posterior descending artery (PDA). The authors prospectively studied the angiographic findings of 607 patients who underwent coronary angiography. The incidence of the angiographically demonstrated PRDA and its distinction from other epicardial branches arising from the distal third of the RCA was the main point of interest. Two types of PDA in those cases where PRDA was present were also demonstrated. Of the patients examined, 535 had dominant right coronary circulation, 59 had left dominant coronary circulation, and 13 had balanced coronary circulation. PRDA was present in 81 patients with right dominant coronary circulation (15.1%), in 2 patients with balanced coronary circulation (15.4%), and in none with left dominant coronary circulation. PRDA was revealed in 48 (40%) of 120 patients with a short PDA and in only 33 (8%) of 415 patients having long PDA. It is imperative to search always for the PRDA, when one is studying coronary arteriographies, bearing in mind that this artery may perfuse the inferior part of the posterior interventricular septum and the adjoining are, depending on the type of PDA.

Angioplasty without the use of "Y connector": a new, easier, bloodless method.

The "Y connector" that is used in angioplasty has the following disadvantages: 1) it is not blood-tight; 2) we need to "screw and unscrew" every time we want to inject contrast material or measure the pressure; and 3) it does not allow the advancement of the guidewire or the balloon catheter during the injection of contrast material. We created a new type of connection composed of a cut sheath for the femoral artery, connected with a cut (at the "hub") guiding catheter. The aim of this study was to examine the feasibility, efficacy, and safety of the new method. Using the new technique we performed plain-balloon angioplasty, implantation of stent, and atherectomy in 350 patients. The technical success of the method was 100%, and no complications related to the method were seen. In conclusion, the novel connection that we created eliminated all the disadvantages of the "Y connector" and was found to have 100% technical success and safety.

Detection of myocardial viability in the prediction of improvement in left ventricular function after successful coronary revascularization by using the dobutamine stress echocardiography and quantitative SPECT rest-redistribution-reinjection 201TI imaging after dipyridamole infusion.

The aim of this study was to assess the feasibility, safety, and respective diagnostic accuracy of low-dose dobutamine infusion and rest-redistribution-reinjection thallium 201 single photon emission computed tomography (SPECT) after dipyridamole infusion (Th-DIP), in the prediction of functional improvement of asynergic infarcted zones, after successful revascularization in patients with chronic ischemic heart disease. Thirty-one patients with a previous myocardial infarction and left ventricular dysfunction (mean ejection fraction: 41 +/- 5.8%) were studied. The regional wall motion of the left ventricle was evaluated by basic echocardiography before and 14 +/- 1.7 weeks after successful revascularization (19 by percutaneous transluminal coronary angioplasty and 12 by coronary artery bypass grafting). Dobutamine stress echocardiography (DSE) was performed in all patients with dobutamine infusion of 5 and 10 micrograms/kg/minute over five minutes. Within three days after DSE and prior to revascularization, all patients underwent Th-DIP for myocardial viability assessment. A 16-ventricular-segment model was used for basic, DSE, and Th-DIP images. Viability was assessed by applying the standard criteria for each technique. In the 31 patients, 496 segments were analyzed. By basic echocardiography, 164 (33%) of them were classified as asynergic. The DSE detected viable tissue in 69/496 (14%) segments, whereas Th-DIP identified viability in 95/496 (19%) segments. When the postrevascularization basic echocardiographic study was used as the gold standard in identifying myocardial viability, the sensitivity and specificity for the DSE and Th-DIP were 86.5%, 94.4% and 90.5%, 69%, respectively. No major side effects were observed with both techniques. In conclusion, DSE seems to be an accurate method for identifying viable but asynergic myocardium in patients with chronic ischemic heart disease, whereas Th-DIP overestimates the postrevascularization recovery. Detection of hibernating myocardium can be obtained by these two noninvasive methods. However, DSE seems to be more useful in determining the prospective selection of patients who are going to benefit from revascularization.

Doppler echocardiographic study of pulmonary venous flow in mitral stenosis and early after mitral valve replacement.

The aim of the study was Doppler echocardiographic assessment of the effect of mitral stenosis (MS) on pulmonary venous flow (PVF), and of any changes occurring after mitral valve replacement. Fifty patients with MS (22 in atrial fibrillation (AF)) and 28 healthy subjects (control group) underwent transthoracic echocardiographic evaluation of PVF. Fourteen of the 22 patients in AF were submitted in addition to transesophageal echo study before and after mitral valve replacement. Pulmonary wedge pressure was measured in 18 patients. Patients in sinus rhythm (SR) and more than mild MS showed significantly decreased peak velocity and flow velocity time integral of the systolic forward PVF. This finding was more exaggerated in MS with AF. Concerning diastolic forward PVF, patients in SR showed significantly decreased peak velocity and velocity time integral, irrelevant of the degree of MS, while patients with AF exhibited adequate signs of flow. In all patients duration, deceleration time (D-DT) and pressure half-time (D-PHT) of the diastolic forward PVF were significantly increased. The last two parameters correlated with the corresponding variables of mitral flow and with echocardiographically determined mitral valve area and the D-DT of the pulmonary wedge pressure. Concerning reversed PVF, patients with more than mild MS exhibited significantly increased peak velocity and velocity time integral. After mitral valve replacement, a significant increase of diastolic forward peak velocity and velocity time of the PVF were detected. The duration of diastolic forward peak velocity of PVF, D-DT and D-PHT decreased. The systolic forward phase did not change significntly after the valve replacement.(ABSTRACT TRUNCATED AT 250 WORDS)