Muhammad Ammar Rashida, Abida Valaita, Aamir Hussain, Tahir Naveed, Ahmad Noeman, Shahid Hameed.
Left Atrial Size in Non-Valvular Atrial Fibrillation: Percentage increase in diagnosis of Left Atrial size by M-Mode Versus Prolate Ellipse Volume method.
J Cardiovascular Dis Jan ;12(4):101-5.

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia with overall prevalence of 5.5%. AF is associated with left atrial (LA) enlargement. LA enlargement is considered both a cause and effect of the arrhythmia. The aim of the study was to determine the influence of AF on changes in LA size determined by Echocardiography in a population without rheumatic heart disease or any valvular pathology i.e NVAF. OBJECTIVE: 1. To determine the frequency of LA enlargement by M-mode diameter method and LA volume by Prolate Ellipse method in nonvalvular atrial fibrillation patients. 2. To determine percentage increase in the diagnosis of LA enlargement when measured by Prolate Ellipse volume as compared to M-mode diameter method. MATERIAL AND METHODS: This cross sectional study was conducted at Department of Cardiology, Punjab Institute of Cardiology, Lahore for six months from October 2012 to April 2013. 210 patients fulfilling inclusion and exclusion criteria were recruited after obtaining informed consent from Cardiology department of Punjab institute of cardiology Lahore. Each patient was explained about the procedure of the study. Demographic details like age, sex, and address were noted. 12-lead ECG were recorded before echo to document atrial fibrillation. Echocardiographic measurements were averaged for three readings, performed and interpreted by experienced echocardiographer according to standard protocol. LA size was assessed as: One plane indexed LA diameter measurement in left parasternal long axis view (PSLAV). Prolate Ellipse volume measurement calculated by following formula. LA volume = (D1 × D2 × D3) × (0.523). Both values were indexed to body surface area, calculated as follow BSA (m²) = ([Height (cm) x Weight (kg)]/ 3600)½ RESULTS:A total of 210 patients were enrolled in current study. Among these 120 patients (57.35%) were male and 90 (42.65%) were female patients. Mean age was 57.59±14.2 years. Echocardiography of patients showed that 66(31.5%) patients were having normal LADI measured by M-mode diameter method and 54(25.7%) patients were having normal LAVI measured by Prolate Ellipse volume method. While 144(68.5%) and 156(74.2%) patients were having enlarged LA by M-mode diameter and Prolate Ellipse volume method respectively. Percentage accuracy of Prolate Ellipse volume method was 6%. CONCLUSION: In conclusion, LAVI by Prolate Ellipse method gives more accurate measure of LA size than LADI on M-mode echocardiography. KEY WORDS:Non valvular atrial fibrillation (NVAF), Atrial fibrillation (AF), Left atrial diameter index (LADI), Left atrial volume index (LAVI).

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