A noninvasive method for the detection of dual atrioventricular node physiology in chronic atrial fibrillation.

Considering the electrophysiologic study as a reference, the RR interval distribution analysis is a sensitive (88%) and specific (80%) noninvasive method for detecting dual atrioventricular (AV) node physiology. This method may prove useful in selecting patients with atrial fibrillation who are considered appropriate candidates for radiofrequency modification of AV nodal conduction as opposed to AV nodal ablation.

Use of vibrational angioplasty for the treatment of chronic total coronary occlusions: preliminary results.

The aim of the study was to investigate the feasibility and clinical safety of vibrational angioplasty in the treatment of chronic total coronary occlusions and evaluate the clinical and angiographic factors that are predictive of the procedural success and complications of the procedure. Seventy-eight patients with chronic total occlusions (>3 months) resistant to conventional techniques were treated by vibrational angioplasty using a variety of conventional guidewires. Lesions were successfully crossed in 67 (85.9%) cases and antegrade flow was achieved in 59 (75.5%). Major complications (myocardial infarction and tamponade) occurred in two (2.5%) patients, but no fatalities ensued. Angiographically detectable dissections were seen in 23 (29.5%) patients but only resulted in vessel compromise and reclosure in 5 cases. Multiple stepwise logistic regression analysis identified the duration (<6 months, P = 0.008) and the length of the occlusion (<15 mm, P = 0.03) as independent predictors of final success and the age of the patient (<55 years, P = 0.006) as the only independent predictor of procedural complications. Vibrational angioplasty is a safe technique useful in the treatment of chronic coronary occlusive disease. Patients in whom the procedure is likely to prove most successful may be easily identified by clinical and angiographic features (duration and length of occlusion).

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.

Pain intensity in nondiabetic patients with myocardial infarction or unstable angina. Its association with clinical and psychological features.

Sixty nondiabetic coronary artery disease (CAD) patients submitted to coronary angiography were asked to rate (score 0 to 20) pain intensity (RPI) during their last major anginal episode having occurred prior to coronary angiography. This parameter was examined in relation to other variables of CAD and to psychological features. Stepwise regression analysis revealed that RPI was not related to New York Heart Association (NYHA) classification of angina or to angiographic variables. Yet, RPI was found to be significantly affected by psychological features: higher RPI scores were reported by low state anxiety patients (P=0.008), by Type A coronary-prone behavior patients (P=0.02) and by patients with high depression (P=0.03).

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.

Electrophysiologic abnormalities of cardiac function in progressive systemic sclerosis.

The heart has been generally recognized as a target organ in progressive systemic sclerosis. Noninvasive studies have assessed the incidence and prognostic importance of cardiac arrhythmias in these patients. However, detailed exploration of the function of impulse formation and the conduction system of the heart in these patients has never been reported. Therefore, invasive electrophysiologic studies were performed in 30 patients with systemic sclerosis, all of whom had neither obvious cardiac involvement nor cardiac arrhythmias, and in 32 subjects with no evidence of heart disease, who served as a control group. Corrected sinus node recovery time in patients with systemic sclerosis was significantly longer (P < .001) than in the control group, as was the HV interval (P < .05). Of the 30 patients with systemic sclerosis, 10 had an HV interval of 60 ms or longer. In four patients with systemic sclerosis, the recorded AH interval exceeded 125 ms. The intra-atrial conduction time tended to increase to a significant degree (P < .05) in patients with systemic sclerosis. The interatrial conduction time was much longer (P < .001), and the maximal conduction delay to the atrioventricular junction and to the distal coronary sinus was much greater in the patients with systemic sclerosis than in the control group (P < .001 for both). Supraventricular tachyarrhythmias were induced in 15 patients with systemic sclerosis versus 3 control group subjects (P < .001). With respect to corrected sinus node recovery time, AH and HV intervals, atrial vulnerability, and ventricular tachycardia, 3 of the 30 patients with systemic sclerosis had abnormal findings in one of these parameters and 14 had abnormalities in more than one. These results suggest that a broad spectrum of electrophysiologic abnormalities is present in patients with systemic sclerosis, which can be revealed only by invasive studies. Furthermore, this study provides additional support for the hypothesis that diffuse myocardial involvement is characteristic of scleroderma patients, since a number of these patients showed more than one electrophysiologic defect.