A study on clinical profile of patients with atrial fibrillation

Background: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia encountered in clinical practice. This study is about the etiological and clinical profile of paroxysmal, persistent and permanent AF. Aim: The aim of this article was to review the clinical epidemiological features of atrial fibrillation. Materials and methods: A hospital-based descriptive study was conducted among 50 patients, diagnosed as atrial fibrillation in Cardiology Department, from 2016 to 2017. Results: Out of 50 patients with atrial fibrillation, 32% were aged between 60 – 69 years and 42(84%) were females and 8 (16%) were males. Permanent AF was seen in 56% patients. Conclusions: Palpitation followed by dyspnoea was the major symptoms encountered with atrial fibrillation, and in females within the age group of 50 years and above are prone to develop AF.

Efeito da dexmedetomidina sobre a arritmia cardíaca induzida pela adrenalina em cães anestesiados pelo sevofluorano / Effect of dexmedetomidine on the heart arrhythmia induced by the adrenaline in dogs anesthetized by sevoflurane

Avaliou-se o efeito da dexmedetomidina sobre o ritmo cardíaco em 20 cães, sem raça definida, de ambos os sexos e considerados sadios, anestesiados pelo sevofluorano e submetidos a doses crescentes de adrenalina. Os animais foram, aleatoriamente, distribuídos em dois grupos (placebo e dexmedetomidina). No grupo placebo, os animais receberam, por via intravenosa, solução de NaCl a 0,9 por cento, na dose de 0,3ml/kg. Foram considerados dois momentos, M0 e M1, imediatamente antes e após a aplicação, respectivamente. Após 10 minutos, realizou-se a indução anestésica com sevofluorano, por meio de máscara facial vedada, até a perda do reflexo laringotraqueal. Em seguida, procedeu-se à intubação orotraqueal e a manutenção da anestesia foi realizada com a administração de sevofluorano na concentração de 1,5CAM, em circuito anestésico com reinalação parcial de gases. Decorridos 20 minutos da indução anestésica, iniciou-se a administração intravenosa contínua de solução de adrenalina a 2 por cento em doses crescentes de 1, 2, 3, 4 e 5mg/kg/min, por meio de bomba de infusão, com aumento da dose em intervalos de 10 minutos. Imediatamente antes desse acréscimo eram feitas as mensurações (M2 a M6). No grupo dexmedetomidina empregou-se a mesma metodologia substituindo-se a solução de NaCl a 0,9 por cento por hidrocloridrato de dexmedetomidina, na dose de 1µg/kg. Foram registradas as pressões arteriais, em M0 e em M2 a M6, e o traçado eletrocardiográfico, na derivação DII (M2 a M6), considerando-se para efeito estatístico o número total de bloqueios atrioventriculares (BAV) de primeiro e segundo graus e de complexos ventriculares prematuros (ESV), coincidentes com cada dose de adrenalina. Os dados foram submetidos à análise de variância seguida pelo teste de Tukey (P<0,05). Verificou-se que a dexmedetomidina interfere significativamente na condução atrioventricular levando a maior ocorrência de BAV e reduz o número de ESV nas doses infundidas de 2 e 3mg/kg/min ...

The effect of dexmedetomidine on the cardiac rhythm in twenty healthy mongrel dogs of both sexes anesthetized with sevofluorane and submitted to increasing doses of adrenaline was evaluated. The animals were randomly allotted to different treatment groups. Animals of placebo group were intravenous injected with 0.9 percent NaCl solution at 0.3ml/kg/IV. Two moments were considered, M0 and M1, the moments immediately before and after application, respectively. Ten minutes later, the dogs were anesthetized using sevofluorane via face mask until lost of their laringotracheal reflex. Then, orotracheal intubation was performed and maintenance of anesthesia was kept with 1,5MAC sevofluorane using an anesthetic circuit with a rebreathing system. Twenty minutes after anesthesia induction, continuous IV administration of 2 percent adrenaline solution was given at increasing doses of 1,2,3,4 and 5mg/kg/min., every ten minutes, respectively. The moments M2 to M6 were measured immediately before the next increase of dose. In dexmedetomidine group, the same technique was used replacing 0.9 percent NaCl by dexmedetomidine hydrochloride at 1mg/kg. Blood pressures were recorded at M0 and M2 to M6. Electrocardiography line in the derivation DII (M2 to M6) was used to observe the number of atrioventricular blocks (AVB) of first and second degrees and ventricular premature complexes (VPC). Statistic evaluation was performed by analysis of variance followed by Tukey's test (P<0.05). Dexmedetomidine significantly altered the atrioventricular conduction resulting in a higher occurrence of AVB. This drug reduced the number of VPC at 2 and 3mg/kg/min of adrenaline. After administration of dexmedetomidine, reduction of arterial blood pressure up to one hour and reduction of cardiac rate were observed

Transesophageal Echocardiographic Evaluation of Pulmonary Venous Flow in Mitral Stenosis

BACKGROUND: Normally major forward pulmonary venous flow(PVF) into left atrium occurs during systole and early diastole. This is followed by the reversal of the PVF with atrial contraction during late diastole. Chronic increase of left atrial pressure and volume, and decrease of the left atrial compliance might alter the PVF pattern in patients with mitral stenosis. Moreover, the cardiac rhythm could be changed from sinus rhythm(SR) to atrial fibrillation(AF) with the progression of the disease. To elucidate the effect of these changes on PVF, we performed transesophageal echocardiographic(TEE) Doppler examination in 20 patients of mitral stenosis who were going to be taken Percutaneous mitral commissurotomy(PMC). METHOD: We measured the velocities of the PVF by TEE pulsed Doppler examination, and compared it with the hemodynamic parameters measured by cardiac catheterization in 20 patients of mitral stenosis who underwent the PMC. The SR was found in 12 patients and the rest showed established AF. RESULTS: 1) Doppler variables measured by TEE. 2) Hemodynamic parameters measured by cardiac catheterization. 3) In patients with SR, S-PV, S-VTI and S-FVTI showed negative correlation with mean LAP(r=-0.66, -0.67, -0.71, respectively, p<0.05). However in AF group, there is no correlation between Doppler variables and mean LAP. CONCLUSION: In mitral stenosis with SR, systolic PVF decreases with the increase of mean left atrial pressure and finally, diastolic PVE becomes predominant with the development of AF.

Effect of Cardiac Rhythm on Hemodynamic Changes and Pulmonary Arterial Atrial Natriuretic Peptide Levels after Percutaneous Mitral Valvuloplasty

In order to evaluate the effect of cardiac rhythm on hemodynamic changes and pulmonary arterial atrial natriuretic peptide(ANP) levels after percutaneous mitral valvuloplasty(PMV), we measured and analyzed the correlations between hemodynamic parameters and pulmonary arterial ANP levels in 65 patients with mitral stenosis before, 20 minutes, and 24 hours after PMV. The results are as follows: 1) Normal sinus rhythm was present in 49 patients(group1), whereas the other sixteen (group 2) had chronic atrial fibrillation. 2)PMV decreased mean left atrial pressure(LAP) in both groups(p<0.001). Left atrial volume was also reduced after PMV in group 1(p<0.0001), whereas it was not decreased significantly in group 2. 3) Pulmonary arterial ANP levels at 24 hours after PMV decreased significantly in group 1(p<0.001), compared to those prior to PMV. However there was no significantl changes in group 2. 4) In group 1, there was a significant linear relationship between extents of drop in pulmonary arterial ANP levels and LAP, measured 24hours after PMV. These results suggest that ANP secretion might be influenced not only by hemodynamic changes of the left atrium, but also by possible structural changes of left atrial wall induced by chronic atrial fibrillation.