Sustained improvement in myocardial perfusion four to six years after PTCA in patients with a satisfactory angiographic result, six months after the procedure

Of 46 consecutive patients who underwent percutaneous transluminalcoronary angioplasty (PTCA) from April 1980 to August 1982 andwho had a satisfactory angiographic result six months later,one died of cancer and 41 had a detailed evaluation with exercisesingle-photon emission computed tomography (SPECT, 40 patients)or repeat coronary angiography (one patient), 48–78 monthsafter the procedure. During follow-up, two patients had recurrentangina due to progression of coronary artery disease requiringa second PTCA procedure of another coronary artery; one of themlater had a limited myocardial infarction in an area suppliedby the vessel initially dilated. At follow-up, only one patienthad definite angina. All but one patient had a negative exercisetest. Myocardial perfusion during exercise in the PTCA-relatedarea, assessed by SPECT, was normal in 90% of the patients andshowed a limited defect due to reversible ischaemia in the remainingfour (10%). It is concluded that patients with a less than 50%stenosis six months after PTCA show sustained improvement intheir functional status and myocardial perfusion, four to sixyears after the procedure suggesting continued patency of thecoronary artery.     

Long-Term Results After Percutaneous Balloon Mitral Commissurotomy

We are now able to analyze follow-up data up to 10 years after percutaneous mitral commissurotomy (PMC). In clinical terms, several large single-center series confirm the late efficacy of the procedure in a large population, comprising a variety of patient subsets. When the immediate results are unsatisfactory, prognosis is poor and surgery should be carried out when the clinical conditions allow it. Conversely, if PMC is initially successful, the clinical results are excellent and late deterioration is mainly related to restenosis. Preliminary series have shown that repeat balloon commissurotomy may be performed successfully in such patients. The prediction of late results after balloon commissurotomy is multifactorial and based on clinical parameters, valve anatomy, and the immediate results of the procedure. Randomized studies have shown that the long-term results of balloon commissurotomy are as good as those of surgery in patients with favorable characteristics. In the others, there has been no comparative study and patient selection should take into account the multifactorial nature of the prediction of late results. Overall, these good long-term results have led to an increased use of balloon commissurotomy in the treatment of patients with mitral stenosis.     

Solution synthesis of antigenic and inhibiting peptides of the human renin prosegment-2

The [Tyr⁴⁰]preprorenin (40–50) peptide methyl ester, an undecapeptide related to the human renin prosegment, has been synthesized using a stepwise strategy with hydrogenolisable protections on the side chains. The final deprotection was very difficult as observed by ¹ H NMR and reversed phase HPLC. 2D ¹ H NMR spectroscopy of the purified peptide allowed the assignment of all protons.     

Enhanced efficacy of computerized exercise test by multivariate analysis for the diagnosis of coronary artery disease. A study of 558 men without previous myocardial infarction

Multivariate analysis has been proposed to enhance diagnosticaccuracy of the exercise test in coronary artery disease. Toquantify the improvement given by multivariate analysis in comparisonwith ST segment depression alone during exercise test, 558 menwithout previous myocardial infarction were studied retrospectively.All the patients underwent a symptom-limited Bruce protocolwith computer-averaged recordings in v5, a VF, V2. Coronaryangiography was performed within the following 90 days. Prevalenceof coronary artery disease (diameter narrowing of 50%or greater)was 0.56.Among 12 clinical and exercise parameters studied bystepwise multivariate analysis, five were found to reach themaximal accuracy: (1) exercise duration, (2) history of typicalangina, (3) typical angina during the test. (4) age, (5) maximalheart rate. In comparison with ST depression, multivariate analysissignificantly improves accuracy (74.6 vs, 66.8%, P<0.01)by increasing sensitivity (0.68 vs. 0.59, P<0.05) withoutaffecting specificity (0.83 vs. 0.76, NS).Thus, in a group ofmen without infarction and a low prevalence of coronary arterydisease, multivariate analysis with five easily collected variablesis more accurate than ST segment depression alone during exercise.In addition, ST depression did not appear as discriminant asexercise duration for diagnostic purposes. This finding emphasisesthe importance of performing a symptom-limited exercise test.     

Salt-dependent conformational diversity of alternating poly (Glu-Leu)

Alternating poly(Glu-Leu) was synthesized by the condensation of the corresponding dipeptide p-nitrophenyl ester at high concentration. It exhibits a random coil structure in pure water at neutral pH. Addition of monovalent cations, such as NH⁺₄ to a final 0.1 M solution, induces a transition to a water soluble β-structure. The salt effect is quite selective since no transition was observed with Li⁺, Na⁺ or Cs⁺ ions. Addition of 0.5 equiv. of calcium, cobalt or manganese chlorides per glutamyl residue induces similar coil to β-sheet transitions. No polymer precipitation was observed at these very low salt concentrations. Addition of 0.5 equiv. of Cu²⁺ or 0.15 equiv. of Fe³⁺ induces a coil to α-helix transition. Molecular modeling has been used to understand tentatively the main factors controlling the different conformations observed with the various metal ions. © Munksgaard 1997.     

Surgical Catheter Ablation of Ventricular Tachycardia Using Left Thoracotomy in a Patient with Hindered Access to the Left Ventricle

We report the case of a patient presenting with incessant monomorphic ventricular tachycardia resistant to antiarrhythmic drugs, and in whom usual percutaneous vascular or pericardial access to the left ventricle was hindered by mechanical aortic and mitral prosthetic valves. Because an epicardial location was suspected by electrocardiogram features and because access to the target area through the coronary sinus was not possible, we decided to perform a surgically based radiofrequency (RF) ablation. Catheter mapping of the epicardial surface through surgical left lateral thoracotomy in the operating room confirmed the epicardial location of the arrhythmogenic substrate and allowed successful RF ablation of the clinically incessant tachycardia. Combined surgical and electrophysiological approach should therefore be performed when RF ablation is needed in case of unadvisable, difficult, or failed nonsurgical percutaneous access.