Effect of preload and heart rate manipulation on Doppler transmitral flow velocity pattern: search for load--independent parameters.

Pulsed Doppler transmitral flow-velocity provides a non-invasive method for serial evaluation of diastolic function. However confounding influence of loading conditions and heart rate on transmitral flow makes many conclusions suspect. To study the effect of preload, various parameters of Doppler mitral spectrum were studied in 11 patients with stable effort angina, angiographic coronary artery disease and intact global and segmental systolic function, before and after administration of sublingual isosorbide dinitrate (group 1). Following isosorbide dinitrate administration, there was a significant increase in heart rate (p less than 0.001), decrease in left ventricular end-diastolic volume (p less than 0.01), no change in left ventricular ejection fraction and systolic blood pressure. Peak E velocity, E velocity-time integral, E/A velocity time integrals ratio, acceleration and deceleration rates and diastolic filling period were significantly reduced whereas peak A velocity, A velocity time integral, acceleration and deceleration times and atrial filling period were unchanged. In 10 age-matched patients (group 2), atrial pacing performed to achieve similar degree of increase in heart rate as in group 1 (10 +/- 1 vs 12. +/- 4, p = NS), resulted in a decrease in E velocity time integral, E/A velocity time integrals ratio and diastolic filling period (p less than 0.01) without any significant change in any other parameter. Absolute A velocity time integral, acceleration and deceleration times are the only parameters of transmitral diastolic flow-velocity profile which are relatively independent of preload and heart rate provided the change is small.     

Coronary angioplasty of 'complex lesions' in patients with unstable angina

Out of 55 patients subjected to coronary angioplasty over the past 12 months, there were 33 (60%) who had unstable angina. Amongst these, 22 patients had coronary lesions classified as 'complex' on coronary angiography. These included tandem lesions, branch stenoses, distal lesions, total occlusions, vein graft stenoses, lesions with ulceration and intraluminal clot and associated with valvular lesions. We describe our experience of coronary angioplasty in these 22 patients of unstable angina having 'complex lesions'. All were males with a mean age of 48.7 +/- 13 years. Fourteen patients had single vessel and 8 multivessel disease. A total of 35 lesions were subjected to dilatation. The angiographic primary success was achieved in 85.7% of the lesions attempted. Except total occlusions and very distal lesions, all other types of 'complex lesions' could be dilated with a success rate of greater than 75%. There were 4 (11.4%) failures because of inability to cross the lesion with the guidewire or balloon catheter. One patient developed non-Q wave inferior wall infarction. There were no deaths. We conclude that coronary angioplasty of various types of 'complex lesions' can be performed with a good primary success and negligible complications in our setting.     

Coadministration of liposomal methylglyoxal increases the activity of amphotericin B against Candida albicans in leukopoenic mice

Abstract

In this study, we investigated the therapeutic efficacy of a combination of liposomal amphotericin B (Lip-Amp B) and Methylglyoxal (Lip-MG) against Candida albicans in the leukopoenic mice. The antifungal efficacy of Lip-Amp B or Lip-MG or a combination of Lip-Amp B and Lip-MG was evaluated by the analysis of the survival rate and the fungal load in the treated mice. The immune-stimulatory effect of Lip-MG on macrophages was evaluated by analysing the secretion of proinflammatory cytokines. C. albicans infected mice treated at the doses of 1 and 2?mg/kg of Lip-Amp B showed 20% and 50% survival rates, respectively. Whereas the mice treated with free Amp B at the same doses died within 40?days of treatment. Interestingly, C. albicans infected mice treated with a combination of Lip-Amp B and Lip-MG had 70% survival rate on day 40 postinfection. Moreover, treatment of macrophages with Lip-MG increased their fungicidal activity and the secretion of proinflammatory cytokines, including TNF-α and IL-1β. These findings suggested that co-treatment with Lip-Amp B and Lip-MG had a synergistic effect and could be effective against C. albicans in immunocompromised subjects.     

Double outlet right ventricle with calcified rheumatic mitral stenosis.

A 21-year old female patient diagnosed to have double outlet right ventricle, ventricular septal defect, pulmonic stenosis and right-to-left shunt on cardiac catheterisation in childhood, presented with a recent onset right sided hemiparesis and congestive heart failure. Investigative data revealed atrial fibrillation, severe calcific mitral stenosis and multiple left atrial thrombi in addition to the previously reported findings. The diagnosis was confirmed by cross-sectional and colour Doppler echocardiography.     

Unidirectional complete heart block.

Forty-two patients with complete heart block were subjected to electrophysiological studies wherein apart from localization of the site of the conduction defect, ventricular pacing was done to assess ventriculo-atrial (VA) conduction and concealed ventriculo-nodal (VN) conduction. There was evidence of retrograde conduction in the presence of orthograde CHB in 22 patients (52.4 per cent). Fifteen patients (35.7 per cent) had VA conduction and seven (16.6 per cent) had concealed VN conduction. In patients with supra-Hisian CHB, three of the nine patients had VA conduction while of the 11 patients with intra-Hisian CHB, six had retrograde conduction (four with VA and two with concealed VN conduction). In the infra-Hisian CHB group, of the 22 patients, eight had VA conduction and five had concealed conduction. Incremental ventricular pacing induced VA Wenckebach periods at VPR from 110 to 133/minute with a VA interval of 110 to 130 msec. In view of the induction of Wenckebach VA periods, the recording of retrograde H potentials in some cases, and relatively long VA conduction time, it is surmised that retrograde conduction in the presence of orthograde CHB takes place through the AV conduction system.     

Can mitral regurgitation after balloon dilatation of the mitral valve be predicted?

OBJECTIVE--To determine which factors predict the occurrence of mitral regurgitation after balloon dilatation of the mitral valve for rheumatic stenosis. DESIGN--Analysis of a case series of patients with rheumatic mitral valve stenosis who had had successful balloon dilatation of the mitral valve. SETTING--A tertiary care centre with an experience of over 150 balloon dilatations of the mitral valve. PATIENTS--70 young patients with non-calcified rheumatic mitral stenosis, who had undergone successful balloon dilatation of the mitral valve. No patient had mitral regurgitation or atrial fibrillation before dilatation. INTERVENTION--Dilatation of the mitral valve by the transvenous, transatrial double balloon technique. MAIN OUTCOME MEASURE--Development of mitral regurgitation after balloon dilatation of the mitral valve and its relation to age, mitral valve area before dilatation and after dilatation, the degree of mitral subvalvar pathology, and the size of balloon used for dilatation. RESULTS--In 10 patients (14%) mitral regurgitation developed after balloon dilatation of the mitral valve. No statistically significant differences were found between patients who did not develop regurgitation and those who did in terms of age (mean (SD)) (19.9 (6.46) v 19.4 (5.5)), mitral valve area before dilatation (1.05 (0.33) v 0.94 (0.4) cm2) and after dilatation (2.52 (1.06) v 2.45 (1.1) cm2), mitral subvalvar pathology assessed by the mitral subvalvar distance ratio (0.116 (0.03) v 0.118 (2.32), or balloon diameter corrected for body surface area (21.37 (3.5) v 20.57 (2.32) mm/m2. CONCLUSIONS--In this subset of children and young adults with non-calcified mitral stenosis, none of the morphological, technical, or patient characteristics studied predicted the development of mitral regurgitation after balloon dilatation. The low incidence of mitral regurgitation may have reduced the discriminatory power of this study. None the less, the means and standard deviation for each factor in each group suggest that even in a larger sample size the variables would have little predictive capacity.