PubMed Health⌕ Search

Biomedical subjects

A Johan

Publications and source records attributed to A Johan.

At least 37 records · Page 2Linked to original sources
PubMed1996

Technically demanding Inoue-balloon mitral commissurotomy: broadened indications for the procedure.

Although percutaneous transvenous mitral commissurotomy (PTMC) is now the preferred treatment modality for selected patients with mitral stenosis, there are certain settings where its application remains controversial or even contraindicated, mainly because of an increased risk of major complications. In this report, 3 such complex PTMC cases are described. A 39-year-old female with a rare combination of mitral stenosis and concomitant sizeable atrial septal aneurysm underwent a successful PTMC procedure. PTMC in a 60-year-old female with coexisting severe kyphoscoliosis which required major adjustments to the transseptal technique yielded an improvement in the mitral valve area from 1.0 cm2 to 1.9 cm2. In the third patient who was in her 25th week of gestation and had evidence of congestive cardiac failure, an abbreviated and expeditious PTMC procedure was carried out uneventfully. The 3 cases reported here highlight the feasibility, safety and efficacy of complex PTMC in the presence of atrial septal aneurysm, severe kyphoscollosis and pregnancy.

Adult↗
PubMed1996

Safety and efficacy of percutaneous Inoue-balloon mitral commissurotomy.

BACKGROUND: Although percutaneous transvenous mitral commissurotomy (PTMC) is currently accepted as the first-line treatment modality for selected patients with mitral stenosis, technical failures and the potential risk of inadvertent cardiac perforation with tamponade, resultant severe mitral regurgitation and death associated with the procedure continue to be important issues of concern. OBJECTIVES: The purpose of this study was to assess the safety profile and acute results of Inoue-balloon PTMC in a consecutive series of 50 patients with symptomatic significant mitral stenosis who underwent the procedure between January 1993 and August 1994. RESULTS: PTMC was successfully completed in all patients without encountering cardiac perforation, cardioembolism, severe (> or = grade 3+) angiographic mitral regurgitation or death. The mitral valve area increased from 0.8 +/- 0.2 cm2 to 1.7 +/- 0.4 cm2 (p = 0.0001) as assessed echocardiographically. Optimal results defined as a valve area improvement of > or = 50% and/or a final valve area of > or = 1.5 cm2 without significant mitral regurgitation (> or = 2 grade increase in mitral regurgitation or a final regurgitation > or = 3+) was obtained in 94% of patients. CONCLUSION: We confirm that Inoue-balloon PTMC is a safe and highly effective procedure as reflected by the absence of cardiac perforation, cardioembolism, severe mitral regurgitation or death and the excellent enlargement in mitral valve area. Furthermore, in our study the clinical restenosis rate was low with the majority of patients maintaining their improved functional status over a 14-month follow-up period.

Adult↗
PubMed1995

Controversies in balloon mitral valvuloplasty: the when (timing for intervention), what (choice of valve), and how (selection of technique)

Despite the established role of percutaneous balloon mitral valvuloplasty (BMV) in the treatment of mitral stenosis, major controversial issues in the realm of BMV persist. With increased operator experience, BMV has now been extended to include various controversial scenarios, such as mild mitral stenosis, adverse valve morphologies, and high-risk patients with concomitant anatomic distortions which are technically demanding. In skilled hands, however, BMV has yielded a favorable outcome in these settings. Furthermore, the debate on whether the Inoue or the double-balloon approach is superior continues. Studies to date have shown equal efficacy of the two BMV methods in terms of valve enlargement although the Inoue approach is clearly simpler to execute and may potentially be associated with a lower risk of creating severe mitral regurgitation. Last, because of the lack of consensus on optimal balloon sizing for BMV, perhaps the best method to adopt at this stage is one that is simple and safe to apply across a broad spectrum of valve anatomy.

Catheterization↗
PubMed1995

Percutaneous balloon valvuloplasty in mitral restenosis after previous surgical commissurotomy.

OBJECTIVES: The aim of this study was to determine the safety profile, mitral valve outcome and follow-up functional status after percutaneous balloon mitral valvuloplasty (PBMV) in patients with mitral restenosis post-surgical commissurotomy. METHODS: Sixteen patients with symptomatic mitral restenosis after previous surgical commissurotomy underwent valvuloplasty using the Inoue balloon stepwise dilatation method. Echocardiography was performed before and after the procedure to evaluate the mitral valve area. RESULTS: All procedures were successfully completed without cardiac perforation, thromboembolism, resultant severe mitral regurgitation or death. The mitral valve area improved from 0.9 +/- 0.2 to 1.6 +/- 0.3 (p = 0.0001), accompanied by a significant immediate reduction in the left atrial pressure and transmitral gradient. Compared with PBMV in patients without past mitral surgery, patients with mitral restenosis undergoing PBMV experienced less valve area improvement but the difference was not significant (p = 0.137). Optimal valve enlargement resulting in mild mitral stenosis was achieved in 12 of the 16 patients. Midterm symptomatic benefit was observed in almost all patients. CONCLUSIONS: In view of the excellent success rate, low complication risk, the optimal haemodynamic results and favourable functional outcome afforded by mitral balloon valvuloplasty in patients with mitral restenosis after prior surgical commissurotomy, it is logical that balloon mitral valvuloplasty, where available, should be the initial treatment modality in this group of patients with suitable valve morphology before considering repeat mitral surgery.

Adult↗
PubMed1994

Simultaneous ST-segment elevation in lead V1 and depression in lead V2. A discordant ECG pattern indicating right ventricular infarction.

The major electrocardiographic change in right ventricular infarction (RVI) is ST-segment elevation in leads V4R-V6R. The authors describe a discordant electrocardiographic pattern of ST-segment elevation in lead V1 and ST-segment depression in lead V2 in five patients presenting with acute transmural (Q wave) inferior infarction and RVI. There were 51 patients with transmural inferior infarction from a thrombolytic trial. In 25 patients, the ST-segment in the right-sided precordial leads was elevated by > or = 1 mm indicating the presence of RVI. In 5 of these 25 patients, simultaneous ST-segment elevation of 1.0-8.0 mm (mean, 2.8 +/- 2.9 mm) in lead V1 and ST-segment depression of 2.5 to 4.0 mm (mean, 3.3 +/- 0.6 mm) in lead V2 were also present. The discordant pattern of the ST-segments in leads V1 and V2 is an important and specific sign for RVI.

Adult↗
PubMed1994

Acute outcome of percutaneous Inoue-balloon mitral commissurotomy.

This study examines the acute results and the potential impact, if any, of 16 clinical, echocardiographic, hemodynamic and balloon-related variables on the acute outcomes of Inoue-balloon percutaneous transvenous mitral commissurotomy (PTMC). Of 107 patients, PTMC was successfully completed in 105 (98%) without cardioembolism or death, and resulted in an increase in mitral valve area from 0.8 +/- 0.2 cm2 to 1.7 +/- 0.4 cm2 (p = 0.0001) as assessed echocardiographically. Optimal results defined as a valve area improvement of > or = 50% and/or a final valve area of > or = 1.5 cm2 without significant mitral regurgitation (> or = 2 grade increase in mitral regurgitation or a final regurgitation > or = 3+) was obtained in 96 patients (91%). Significant mitral regurgitation was observed in six patients. On univariate analysis, patients with suboptimal results were older (52 +/- 7 vs. 44 +/- 10 years, p = 0.037) and were likely to have the procedure performed during the learning phase (first 33 vs.. subsequent 72 patients, p = 0.007) than those with optimal results, and patients with resultant significant mitral regurgitation had more severe pre-existing mitral regurgitation compared with those without (1.4 +/- 0.5 vs. 0.7 +/- 0.7, p = 0.0098). However, there were no independent predictors of either acute outcome identified in multivariate analysis. We therefore conclude that although Inoue-balloon PTMC is a safe and highly effective procedure with a low risk of creating severe mitral regurgitation, the acute outcomes cannot be accurately predicted.

Adult↗
PubMed1993

Early ambulation following diagnostic 7-French cardiac catheterization: a prospective randomized trial.

There is a paucity of randomized studies concerning transfemoral cardiac catheterization and its complications, in particular that of 7F catheterization. Accordingly, we conducted a prospective, randomized trial comparing early ambulation (group A) 6 hr after diagnostic 7F cardiac catheterization versus late ambulation (group B) the following morning. A total of 273 patients were randomized in the study; 142 in group A and 131 in group B (NS). Except for a difference in the indications for catheterization, the baseline and procedure-related parameters were similar between the 2 groups. Early hematoma (formed within 6 hr) developed in 6 (4%) and 7 (5%) patients in groups A and B, respectively (NS). Similarly, there was no difference in the incidence of late hematoma formation (2% in each group). All hematomas detected were small and required no surgical intervention or extension of hospital stay. Our data showed that early ambulation following 7F left heart catheterization is feasible and safe. The access site complication rate is acceptably low and minor in nature.

Cardiac Catheterization↗
PubMed1992

Percutaneous transluminal coronary angioplasty in acute cardiogenic shock: an overview of the current strategy with a case illustration.

Cardiogenic shock from severe left ventricular dysfunction remains the most common cause of death in patients with acute myocardial infarction despite the advent of inotropic agents and intra-aortic balloon support. Lytic agents have not convincingly reduced mortality when administered in a shock scenario. Recently, observational studies have demonstrated survival benefit when mechanical revascularisation, particularly balloon angioplasty, is performed early in such patients. In this article, we report a case of an extensive anterior myocardial infarction with cardiogenic shock who underwent successful acute balloon angioplasty and prolonged intracoronary thrombolysis and use it to illustrate the current evolving interventional approach in the treatment of such a complex clinical syndrome.

Acute Disease↗
PubMed1989

PTCA--the initial 100 cases in the Singapore General Hospital.

Percutaneous transluminal coronary angioplasty (PTCA) is an increasingly important technique for the treatment of patients with coronary artery disease. One hundred cases of PTCA were performed in Singapore General Hospital between 1985 to September 1988. 87% were males and 13% were females. The mean age of these patients were 55 +/- 9 SD years (range from 28 to 79 years). 85% had angina pectoris, 43% had a previous myocardial infarction and 12% received intravenous streptokinase previously. One hundred and twenty-nine lesions were dilated. 51% of the cases had single, 40% had double and 9% triple vessel disease. 83% had single, 16% double and 1% triple vessel dilatation. The distribution of the cases by vessel location was 64% for LAD, 19% for RCA and 17% for CX. Overall lesion success was 86%, with an increment in the success rate from 76% in 1987 to 89% in 1988. Similarly, the clinical success rate was 86% for the whole group; it increased from 74% to 90% from 1987 to 1988. The mean diameter stenosis was decreased from 86 +/- 14% SD predilatation to 28 +/- 28% SD postdilatation (p less than 0.005). The mean transtenotic gradient was reduced from 60 +/- 17 mmHg SD predilatation to 18 +/- 11 mmHg SD postdilatation (p less than 0.005). There were 14 failures (14%), the majority of which were due to inability transversing the lesion with a guide wire or balloon catheter. Fourteen complications (14%) occurred in these 100 cases of PTCA. 3% required emergent/semiemergent surgical revascularization. There was no mortality. PTCA is now an established mode of therapy for coronary artery disease in Singapore General Hospital.

Adult↗
PubMed1986

Tomographic thallium-201 stress scintigraphy in the evaluation of coronary artery disease.

57 patients with chest pain, had tomographic thallium-201 stress scintigraphy (TTSS), and coronary angiography within three months of the TTSS. The exercise images were compared with delayed images obtained at 3 hours post-exercise. The sensitivity and specificity of locating individual coronary artery disease was 88% and 100% for disease of left anterior descending artery (LAD), 89% and 83% for right coronary artery disease (RCA), and 24% and 96% for left circumflex artery (LCX) disease. Other than for LCX disease, our results compare favourably with other reports. The overall accuracies are 91%, 86% and 60% for LAD, RCA and LCX disease respectively.

Angina Pectoris↗
PubMed1982

The cardiovascular laboratory at the Singapore General Hospital, 1964-1981.

The invasive cardiac laboratory at the Singapore General Hospital was established in 1964. It was completely renovated and re-equipped in 1975 to cater for all the permutations and combinations that may be required for the safe conduct of cardiac catheterization procedures. A total of 4,849 procedures were done by 33 operators over 18 years. Patients for invasive procedures were usually discussed at the Monday Cardiac Conference prior to a decision being made to study. As such, the selected patients were usually the ill ones and the patients who required cardiac surgery. In the 1807 cardiac catheterizations done between 1975 and 1979, 1137 patients were found to be suffering from congenital heart disease, 586 were found to have acquired heart disease and 46 patients had coronary heart disease. The commonest congenital cardiac defect was atrial septal defect (or patent foramen ovale). Secondary pulmonary hypertension was found in 373 patients with acquired heart disease. Major complications occurred on 149 occasions and these were all in ill patients with severe heart disease.

Cardiac Catheterization↗