STUDY OF CLINICAL, ETIOLOGICAL AND ECHOCARDIOGRAPHIC PROFILE OF ATRIAL FIBRILLATION IN A TERTIARY CARE HOSPITAL

Methods: A cross-sectional research performed on AF cases admitted in SCB MCH, Cuttack, during the period from May 2021 to November 2022. Detailed history, thorough clinical examination and transthoracic echocardiography, has been carried out among study population. Results: Average age of cases was observed as 49.56±17.64 years. Among 100 cases, females were found to be 63% whereas males as 37%. Most of the cases were suffered due to more than one symptoms of severity. About 59% of cases showed rheumatic heart disease (RHD) out of total 100 cases. Among RHD cases, 43% cases were female and the male cases as 16%. Hypertension and coronary artery disease formed the furthermost communal reasons. Mean left atrial (LA) dimension between the study populations was found to be 4.49±0.57 cm. Conclusion: This study concluded that dyspnea seems to be the most common observed symptom; RHD forms the major communal reasons for AF, preceded by hypertension. Mitral valve seems to be involved among all cases of RHD. In major cases, LA enlargement has been reported; therefore, this forms the prognosticator of AF. LA enlargement cases seem to be further susceptible to progress to LA appendage clot.


INTRODUCTION
Atrial fibrillation (AF) occurs to be an utmost recurrent cardiac arrhythmia in daily clinical management.Approximately estimated to a maximum of 6-12 million population seems to be affected with AF in United States by the year 2050 and 17.9 million population in Europe by the year 2060 [1].Approximately, it is stated that AF contributes 1/3 rd of arrhythmia associated admitted cases in healthcare centers.This seems to be a supraventricular arrhythmia considered by less amplitude baseline oscillations (Fibrillatory or F waves from the fibrillating area) and an irregularly irregular ventricular rhythm [2].Documentation of these disorders appears to be significant since this is connected through substantial morbidity and mortality.
AF shows considerable significances in the study populace, counting compromised eminence of life, augmented hospitalization rates, stroke manifestation, and improved therapeutic budgeting's.Possibly, the significant magnitude of AF has improved the risk of stroke associated to the overall population, reporting approximately 25% of all strokes [3].This too also connected with the progress of heart failure; and in turn related to unpredicted demise.
Occurrence upsurges with age, with >95% of AF cases were found to be in the age category >60 years.The frequency of the study population above the age of 80 years was found to be approximately 10%.The lifetime threat of emerging AF for males around the age of 40 years was found to be approximately 25%.AF is somewhat further communal in males when compared to females and this is also very particular among whites than blacks [3].
AF frequently indicates the ultimate communal path for a multitude of further predisposing cardiac as well as non-cardiac circumstances.Threat factors for emerging AF, along with age criteria and essential cardiac disorders comprise hypertension, diabetes mellitus, obesity, and sleep apnea [3].AF seems to be the furthermost most common arrhythmia which necessitates clinical management because it is regularly observed in experimental therapy.Although, most of the cases with AF seems to be comparatively asymptomatic, all cases have intensely restrictive symptoms because of prompt or slow basal ventricular rates, a prompt cardio accelerator reaction to exercise, beat to beat in discretion with connected palpitations, also the loss of atrial systolic influence to ventricular filling leading to reduced cardiac output.
Enhanced recognition of scientific epidemiology of AF, beside with an improved appreciation of the mechanisms, is necessary for the progress of the developed procedures for AF inhibition.This current observation has been designed to investigate the clinical, etiological, and echocardiographic profile of AF in study populace.

METHODS
Analysis of the clinical, etiological, and echocardiographic profile of AF in study population of 100 cases was performed as a cross-sectional research during the period from May 2021 to November 2022 in the Department of General Medicine and Cardiology, SCB Medical College, Cuttack.The Institutional Ethical Committee approval has been obtained proceeding to the research initiation.

ECG recordings
12 lead ECG was done in all patients with a calibration of 1 mV=10 mm, with the paper speed at 25 mm/s variables, namely, absence of P-wave; irregularly irregular RR interval; atrial activity reflected by an irregularly corrugated deflection "f" wave were estimated.For all the study population, among all cases enrolled into the study, a thorough examination including physical investigations was carried out.
Complete blood count, plasma sugar values both fasting and 2-h postprandial, HbA1C, thyroid function test, PT/INR, Chest X-ray PA View, Pulmonary Function Test in case of suspected COPD cases, Transthoracic, M -mode, and 2 Dimensional and Color Doppler Echocardiography were carried out among all cases with the subsequent features namely: Furthermore, coronary angiography for suspected coronary artery disease (CAD) was performed among all the patients.Patients were categorized as per LA size enlargement based on American society of echocardiography.For cases who established stroke as a complication of AF, NCCT brain was taken and the features were observed and documented.

Statistical analysis
Interpretation of data was implemented using SPSS software version 21.0.

RESULTS
Among 100 cases, those who diagnosed with AF were comprised in the research.AF affected in various age categories varying from 18 to 82 years and only 3% was observed to be less than the age of 20 and more than the age of 80 years.Mean age among the patients was found to be 49.56±17.64years (Table 1).
The gender distributions among the patients are depicted in Table 2. Female patients were more than the male category affected with AF.Dyspnea (Fig. 1) seems to be a very commonly observed symptom among the study population with 84%.Subsequently followed by other symptoms, palpitation with 44% of the study population was observed.Among these 100 cases, seven patients were found to be asymptomatic.
In this present study, rheumatic heart disease (RHD) (Fig. 2) (59%) seems to be the supreme common etiological factor connected with AF.Subsequently followed by hypertension (15%), proceeded by CAD (12%).Some of the other less common causes included cardiomyopathies, COPD, thyroid disorders, and lone AF.

Echocardiographic parameters
In 59 patients with valvular lesions (Table 3), isolated mitral stenosis (MS) showed leading valvular lesion with 49%, followed by MS with mitral regurgitation (MR) having 37%.Aortic valve involvement has been observed among 11% of the patients.Only 3% reported to undergo mitral valve replacement.
Heart rate (HR) seems to be >140/min which is associated with 67% of the patients with clot, whereas 1.2% with a HR <140/min with clot on echo (Fig. 3).The presence of clot was significantly different between HR more than 140 and <140 (p=0.001).
In 13 cases with a clot on echo (Fig. 4), 69.2% cases showed established CVA (embolism) while among 87 patients who did not have a clot on echo, 11.5% cases established CVA (embolism).The development of CVA (embolism) was significantly different between presence and absence of clot on echo (p=0.001).
In our study (Table 4), mean LA size in RHD cases were 4.855±0.44cm.Mean LA size among non-RHD cases patients was 3.973±0.25cm.Mean LA size was statistically significant among RHD and non-RHD cases (p=0.0001).
All male cases with LA enlargement (Fig. 5), 27.8% of them found to have LA clot on echo whereas patients not having LA enlargement did   not show any clot on echo.LA enlargement showed significantly higher incidence of clot on echo (p=0.013).LA enlargement in relation to clot on echo in females was shown in Fig. 6.

DISCUSSION
Mean age of AF in this observation was found to be 49.56±17.64years.
AFFIRM study [4] stated mean age in their results as 70 years.Females (63%) were affected more in numbers than males (37%) in this study.
Rendering to AFFIRM observation, prevalence rate among male cases was found to be 61%.Framingham cardiac research [5] described a greater prevalence among male population.With this report of 100 cases, the etiology of RHD was found to be among 59 cases.Mean age in RHD patients was 49.02±18.66years.Morin et al. [6] documented that the etiology of 70% of population as RHD.AFFIRM research showed precise short prevalence of RHD in their documented research.
Most of the reports documented among tropical countries revealed a greater prevalence of AF in RHD than the Western population.The subsequent reasons for AF in this study were found to be hypertension with 15% of the study population.
As per Framingham research [5], half of the cases were accounted for hypertension.According to AFFIRM study [4], hypertension was observed among 71% of cases.The relationship of AF with hypertension was found to be decreased in this current report than the above trials.CAD was observed with 12% of the study population.AFFIRM [4] research documented that CAD with 38% of the cases.Lévy et al. [7].reported 16.6% of CAD as the principal reason that is almost comparable with our obtained observations.Thyroid dysfunction was seen in five cases of which three had overt hyperthyroidism, and two reported overt hypothyroidism.Auer et al. [8] stated that AF observed in 13.8% with overt hyperthyroidism; 12.7% with sub-clinical hyperthyroidism.Barbisan et al. [9] study revealed that 72 cases with AF, 16.6% with thyroid dysfunction in that 5.6% with hypothyroidism.
Dyspnea is observed to be the utmost communal symptom reported among 84% along with 44% with palpitation.Tischler et al. [10] documented that Dyspnea among 62% of patients and palpitation among 33% of patients.Flaker et al. [11] stated that 78% with dyspnea; 11% with chest pain.Out of 59 patients of RHD, isolated MS seems to be the leading valvular lesion (49%), followed by MS with MR (37%).Aortic valve involvement is observed in 11% of patients.Sharma et al.Ul Hassan et al. [15] reported in his study that the incidence of LA appendage clots on trans-esophageal echocardiography in cases with severe MS seems to be most communal and additional recurrent in cases with AF and LA dimension as ≥45 mm.
In male cases with LA expansion, 29% with rigorous LA expansion showed CVA and 33% with rational LA expansion among CVA.Whereas in the female cases with LA expansion, 29% with severe expansion among CVA and 2% with adequate expansion in CVA.LA expansion showed greater occurrence of CVA (embolic) (p=0.072;nearly significant).Xue et al. [16] described that among 313 cases; LA size seems to be an independent prognosticator of overall recurring ischemic strokes and the composite of frequent cardioembolic and/or cryptogenic stroke.

CONCLUSION
Average age of AF seems to be 49.56±17.64years.Female cases were found to be suffered a lot when compared to the male population.Dyspnea observed to be the maximum communal observed symptom, correspondingly palpitation as the next symptom.RHD reported as another furthermost commonly observed etiological factor proceeded by hypertension and CAD.Mean age in RHD patients was 49.02±18.66years.Principal valve exaggerated seems to be the mitral valve together in isolation and combination.Higher cardiac rate >140/ min found to be the risk factor for clot formation.Occurrence of clot on echo augmented the threat of CVA (embolism).Mean LA size significantly differed in RHD and non-RHD patients (p=0.0001).LA enlargement showed a greater prevalence of clot on echocardiography embolic stroke.Meticulous evaluation of risk factors and prompt treatment will reduce the complications, morbidity, and mortality.

Limitations of the study
The study population seems to be too less and the research was performed in a single tertiary care center.It is a cross-sectional research and the follow-up of the patients were not done.Furthermore, peripheral embolism and transesophageal echo were not done for this study.