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 Table of Contents  
ORIGINAL ARTICLE
Year : 2015  |  Volume : 29  |  Issue : 1  |  Page : 40-44

Clinical profiles and outcomes of patients undergoing pacemaker implantation


1 Department of Medicine, Regional Institute of Medical Sciences, Imphal, Manipur, India
2 Department of Cardiology, Regional Institute of Medical Sciences, Imphal, Manipur, India

Date of Web Publication17-Jun-2015

Correspondence Address:
Dr. Vilas Yadavarao Kanse
#2 PG Gents Hostel, 5A, Regional Institute of Medical Sciences (RIMS), Imphal, Manipur
India
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/0972-4958.158933

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  Abstract 

Background: The insertion of a permanent cardiac pacemaker is today one of the most commonly performed interventions on the heart. Various hypotheses have been put forward to explain the high incidence of conduction system disorders in the eastern part of our country. We studied the clinical profiles and outcomes of patients undergoing pacemaker implantation at the Regional Institute of Medical Science Imphal, Manipur, India. Materials and Methods: Thirty-seven patients who satisfied the inclusion criteria and underwent pacemaker implantation were studied. Detailed evaluation was done for each patient. Electrocardiography (ECG), echocardiography, chest x-ray, lipid profile, and other routine investigations were carried out. Patients were followed up for 6 weeks for any acute complication of pacemaker implantation. Results: Of the 37 patients, 21 (57%) were male, and the mean age of the study group was 63.24 years. The indications for pacemaker implantation were atrioventricular (AV) block [in 24 (64.9%) patients], sick sinus syndrome (SSS) [10 (27.1%)], and trifascicular block [3 (4.5%)]. The most common presenting symptoms were syncope (in 59.9% of patients), lightheadedness (62.2%), palpitation (56.7%), and dyspnea (56.7%). Cardic arrhythmias were associated with hypertension (in 59.5% of patients), diabetes mellitus (21.6%), thyroid disease (16.2%), and coronary heart disease (CAD,13.5%). In 32.4% of the patients there were associated comorbid conditions. No further syncopal attack occurred following pacemaker implantation, and the other symptoms improved significantly. The complications observed were pneumothorax and pacemaker implant site wound exudation in one patient each. Conclusion: The major indications of pacemaker implantation were found to be complete heart block (CHB) and SSS. Pacemaker implantation is a lifesaving procedure and improves quality of life dramatically. Complications associated with pacemaker implantation are relatively low.

Keywords: Atrioventricular (AV) block, Pacemaker implantation, Sick sinus syndrome (SSS), Trifascicular block


How to cite this article:
Kanse VY, Chongtham DS, Salam KS, Nemichandra S C, Upretti S, Singh SD. Clinical profiles and outcomes of patients undergoing pacemaker implantation. J Med Soc 2015;29:40-4

How to cite this URL:
Kanse VY, Chongtham DS, Salam KS, Nemichandra S C, Upretti S, Singh SD. Clinical profiles and outcomes of patients undergoing pacemaker implantation. J Med Soc [serial online] 2015 [cited 2019 Dec 13];29:40-4. Available from: http://www.jmedsoc.org/text.asp?2015/29/1/40/158933


  Introduction Top


The insertion of a permanent cardiac pacemaker is today one of the most commonly performed interventions on the heart and is certainly the most successful form of cardiac intervention involving a prosthesis. A completely implantable permanent cardiac pacemaker was described by Elmquist and Senning in 1959 and by Chardack and associates in 1960. During subsequent years, developments in this field have been rapid and wide-ranging, affecting every aspect of the medical and surgical treatment of heart disease. [1] Cardiac pacing was introduced in India in 1966. The first pacing was performed in April 1967 at the Institute of Post Graduate Medical Education and Research (IPGME&R). Bhatia et al. started pacemaker implantation at the All India Institute of Medical Science (AIIMS), New Delhi in 1968. [2]

Worldwide, the prevalence of third-degree atrioventricular (AV) block and sick sinus syndrome (SSS) is 0.04% [1] and 0.296%, [3] respectively, whereas the prevalence of trifascicular block is 0.1% in the younger population and increases to 1% in the older population. [4] Regarding clinical features, "symptomatic bradycardia" is defined as a documented bradyarrhythmia that is directly responsible for the development of frank syncope or nearsyncope, transient dizziness or lightheadedness, and confusional states resulting from cerebral hypoperfusion attributable to slow heart rate. Patients who experience tachyarrhythmias usually present with a sensation of palpitation, chest pain, or pressure, rather than an abrupt loss of consciousness. [5]

Various hypotheses have been put forward to explain the high incidence of conduction system disorders in the eastern part of our country. Mustard oil is the usual cooking medium in the eastern part of the country. The erucic acid content of mustard oil is around 48%. Erucic acid has been shown to produce myocardial fibrosis and lipidosis. A high incidence of heart block has also been reported from Sweden, where the cooking medium is rapeseed oil, which also has a high erucic acid content. [2] There are not many studies from the northeastern part of India, in view of which we conducted a study at the Regional Institute of Medical Science, Imphal, Manipur to assess the clinical issues, biochemical factors, imaging, complications, and outcomes of the patients undergoing pacemaker implantation.


  Materials and Methods Top


Thirty-seven patients with symptomatic bradyarrhythmias or asymptomatic cases with heart rate <40 beats/min were registered for the study after written informed consent was obtained. The study setting was the Department of Medicine, Regional Institute of Medical Sciences, Imphal, over a period of 1 year with effect from October 2011. The aims of the study were to evaluate the clinical profiles of patients undergoing permanent pacemaker implantation and to access outcomes and complications associated with permanent pacemaker implantation.

Patients with reversible bradyarrhythmias, drug-induced bradycardia, and electrolyte imbalance-induced bradyarrhythmias; patients not willing to participate in the study; patients undergoing revision implantation; and patients aged <18 years were all excluded. Detailed histories regarding symptoms such as syncope, lightheadedness, palpitation, dyspnea, edema, angina, fatigue, and cerebrovascular accidents was taken. Detailed clinical evaluation was done, followed by investigations including complete hemogram, blood glucose, blood urea and creatinine, lipid profile, thyroid profile, chest x-ray, and echocardiography.

Patients satisfying the inclusion criteria, after the exclusion of the possible reversible cause of bradycardia, underwent permanent pacemaker implantation under the cover of transfemoral temporary pacemaker implantation. The permanent pacemaker was implanted using a subclavian vein approach on the right side of the chest. All the patients were administered with prophylactic intravenous antibiotic starting 1 h before intervention and continuing for 5 days. Teicoplanin, gentamicin, and ornidazole were given for Gram-positive, Gram-negative, and anaerobic coverage, respectively. After 5 days of intravenous antibiotics, oral amoxicillin clavulanate and levofloxacin were given for another 5 days. Patients were followed up closely for 6 weeks for the monitoring of early complications associated with pacemaker implantation, such as implant-related complications, lead-related complications, pacemaker site infection, hematoma formation, and thrombus formation.

Statistical methods

Descriptive and inferential statistical analysis has been carried out in the present study. The results of continuous measurements are presented as mean ± SD (min-max) and the results of categorical measurements are presented as number (%). Significance was assessed at 5% level of significance. Statistical software applications, namely SAS 9.2 SAS Institute Inc., SAS Campus Drive, Cary, North Carolina 27513. SPSS 15.0 SPSS Inc. 233 South Wacker Drive, 11th Floor, Chicago, IL 60606-6412 Tel: (312) 651-3000 Fax: (312) 651-3668, Stata 10.1 StataCorp LP, 4905 Lakeway Drive College Station, Texas 77845-4512, USA, MedCalc 9.0.1, Systat 12.0, and R environment ver. 2.11.1 Peter Dalgaard Center for Statistics, Copenhagen Business School, Solbjerg Plads 3, 2000 Frederiksberg, Denmark, Phone: (+45)38153501, Email: pd.mes at cbs.dk were used for the analysis of the data.


  Results Top


Thirty-seven patients, of whom 21 (56.8%) were males and 16 (43.2%) females), and who had undergone permanent pacemaker implantation were enrolled in this study. The study population consisted of 24 (64.9%) patients of AV block, 10 (27.1%) patients of SSS, and 3 (8.0%) patients of trifascicular block. The demographic and other baseline characteristics of the study population are shown in [Table 1].
Table 1: Demographic and other baseline characteristics of the study population


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Of our patients, 91% were symptomatic at presentation, and these symptoms were attributed to bradycardia. The most commonly presenting symptoms were syncope, lightheadedness, palpitation, and dyspnea, in 59.9%, 62.2%, 56.7%, and 56.7% of patients, respectively. Three patients did not have any symptoms but had heart rate <40 beats/min. The symptoms in these various groups are shown in [Table 2].
Table 2: Symptoms in various groups


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In the present study, 89.1% of patients presenting with bradycardia had heart rates less than 50 beats/min and 40.5% of patients had heart rates <40 beats/min, with a minimum heart rate of 28 beats/min. Three patients with heart rates >60 beats/min at presentation belonged to the brady-tachy syndrome group. The mean heart rate in the AV block group was much lower (39.26 ± 6.11) compared to SSS (53.40 ± 21.08) and trifascicular block (47.33 ± 12.06) and P = 0.017. Overall, 43.2% of patients had cardiomegaly on x-ray chest. In the AV block group, 45.8% had cardiomegaly, whereas in the SSS group 40% and in the trifascicular group 33% did. In the present study, we observed that 75.6% of patients had normal left ventricular systolic function on 2D echocardiograhy, that is, the ejection fraction (EF%) >50%. Left ventricular systolic dysfunction with EF <50% was observed in 24.3% of patients. The percentages of patients with mild, moderate, and severe left ventricular systolic dysfunction were 13.5%, 5.4%, and 5.4%, respectively. One patient with severe depressed left ventricular ejection fraction (LVEF) presented with acute myocardial infarction.

In the present study, 70.3% of the patients underwent the single-chamber, rate-responsive pacing (VVIR) type of pacemaker implantation. The dual-chamber, rate-responsive pacing (DDDR) type of pacemaker was implanted in 29.7% of patients who belonged to the complete heart block (CHB) group. Following permanent pacemaker implantation, there was dramatic improvement in the symptoms of the patients. There was no further episode of syncopal attack in any of the patients, and lightheadedness subsided, while dyspnea and fatigue improved considerably. Palpitation was still persistent in 4 patients, of whom 3 patients had brady-tachy syndrome. Palpitation in these patients was controlled by usage of oral antiarrhythmic drugs for controlling tachycardia.

In present study, only 2 patients had complications: 1 had pneumothorax and 1 had pacemaker site wound exudation. The pneumothorax was mild in nature and the patient did not have any symptoms, recovering without any intervention. Wound infection was suspected in 1 patient, as the patient had exudative discharge from pacemaker site incision on the third postoperative day, but the pus culture was sterile. The patient's wound healed with daily dressing and the intravenous antibiotics teicoplanin and gentamicin, which were given for 5 days. [Table 3] shows the complications in the pacemaker implantation patients in our study.
Table 3: Complication in pacemaker implantation patients


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  Discussion Top


The present study was conducted to evaluate the clinical characteristics and outcomes of patients with cardiac conduction defect undergoing pacemaker implantation in one of the states of northeastern India where the prevalence of heart block is relatively high. In the present study, 37 patients underwent permanent pacemaker implantation over a period of 1 year. Of these, 24 (65%) patients were suffering from AV block, 10 (27%) from SSS, and 3 (8%) from trifascicular block. In the AV block group, 20 patients were suffering from CHB and 4 patients had advanced second-degree AV block. In the SSS group, 7 patients were suffering from bradycardia, whereas brady-tachy syndrome manifested in 3 patients. In the present study, the major indication of pacemaker implantation was CHB, perhaps because of the poor prognosis associated with it, whereas SSS does not decrease life expectancy. In the study by Shaw et al. [6] of 381 patients of SSS, in the follow-up period of 10 years, only 61 patients underwent pacemaker implantation, and they concluded that the overall survival of patients with established and potential dysfunctions was similar and apparently indistinguishable from that of the normal population. Pacemaker implantation had little discernible effect on mortality, though it reduced some incapacitating symptoms.

The youngest patient in our series was 25 years old, and the mean age of study group was 63.24 ± 14.85 years. In the study population, 78% of patients were clustered in the range of 51-80 years of age. Patients with AV block were relatively young compared to those with SSS and trifascicular block. These results are consistent with previous studies. [4],[7],[8] Ninety-one percent (91%) of our patients were symptomatic at presentation, and the overall presenting symptoms observed in the present study were syncope (59.5%), lightheadedness (62.2%), palpitation (56.7%), and dyspnea (56.7%). Palpitation was found to be more frequent in the SSS group, in 90% of those patients, whereas all 3 patients of the trifascicular group were suffering from syncopal attacks. Three patients were asymptomatic at presentation but had profound bradycardia with heart rates <40 beats/min, and of these, 2 patients were suffering from CHB and 1 patient from advanced type-2 second-degree AV block; the observations in our studies were comparable with previous studies. [4],[6],[7],[8],[9],[10],[11],[12],[13]

Hypertension is the most important factor associated with bradyarrhythmias. In our study, we found the association of hypertension to be 59.5% with bradyarrhthymia. The duration of hypertension ranged from 27 years to less than 1 year before the development of symptoms of bradyarrhythmia. None of our patients were on beta blockers, calcium channel blockers (CCBs or dihydropyridines), digoxin, or antiarrhythmics drugs at the time of presentation, which can lead to conduction block and present a similar clinical picture. Hypertension prevalence in the AV block and SSS groups was 62.5% and 40% respectively, whereas all 3 patients with trifascicular block were hypertensive. Thyroid dysfunction was noticed in 6 (16.2%) patients; of these, 2 patients were suffering from hyperthyroidism and the rest from hypothyroidism. AV block was noted in 4 patients and SSS in 2 patients. The patients were on antithyroid and thyroxine hormone replacement for hyper- and hypothyroidism respectively. In spite of therapy with adequate dose and normalization of thyroid functions, bradyarrthymia did not improve in these patients, and hence these patients underwent pacemaker implantation. Ozcan et al. [14] performed a study on 668 patients with AV block, among whom 50 patients had thyroid disease (29 patients had hypothyroidism and 21 had hyperthyroidism); in spite of optimal treatment for thyroid dysfunction and normalization of thyroid functions, the patients did not recover from AV block, and 44 of those 50 patients had to undergo permanent pacemaker implantation. Diabetes mellitus was found in 8 (21.6%) of our patients. None of our patients were suffering from type 1 diabetes mellitus. Five of our diabetes mellitus patients had CHB, whereas 2 had SSS and 1 had trifascicular block. Diabetes mellitus was found to be significantly associated with CHB in the present study, which was consistent with previous studies. [15] Coronary artery disease (CAD) was noticed in 13.5% of patients. Twenty-seven percent (27%) of patient presented with features of angina and 1 patient had acute anterior wall myocardial infarction. The diagnosis of CAD was on the basis of history, clinical examination, electrocardiogaphy (ECG), and echocardiography, so this may be the reason for lower prevalence of CAD in the present study. Kostuk et al. [16] performed a study on patients of acute myocardial infarction and in his study population, CHB occurred in 9.1% of patients with acute myocardial infarction. Patients with anterior infarction had a poor prognosis (80% mortality rate) and a widened QRS complex, probably due to the involvement of both bundle branches. In inferior wall infarction, a narrow QRS complex is associated with the heart block, and the mortality rate is 45%. Gupta et al. [17] in their study of CHB with acute myocardial infarction (MI) 4 of 5 patients who underwent transvenous pacing died. At our institute, 18 patients developed CHB following myocardial infarction, and of these, 11 patients had suffered from inferior wall myocardial infarction (IWMI) and 7 from anterior wall myocardial infarction (AWMI). Seven patients of IWMI with CHB reverted to sinus rhythm and the rest 4 patients expired before any intervention. In AWMI group 3 patients underwent temporary pacing, of which one patient survived and underwent permanent pacemaker implantation, rest six patients expired. The etiology of bradyarrhythmia was unknown in 32.4% of the patients.

In the present study, 89.1% of patients had presented with bradycardia, i.e., heart rate <50 beats/min, and among these, 40.5% of patients had heart rate <40 beats/min. The minimum heart rate of 28 beats/min was noticed. All the 3 patients with heart rate >60 beats/min belonged to the brady-tachy syndrome group - we had reviewed their previous records and found that they had paroxysmal atrial fibrillation or supraventricular tachycardia. The mean heart rate in the AV block group was much lower (39.26 ± 6.11) compared to the heart rate in the SSS group (53.40 ± 21.08) and in the trifascicular block group (47.33 ± 12.06), with P = 0.017. The observations in our study were similar to those in the Penton et al. [7] study of CHB, where the average heart rate of 38 beats/min was observed. In the Shaw et al. [6] study of SSS, the patients had a mean heart rate of 58 beats/min. In the present study, overall, 43.2% of the study population had cardiomegaly on x-ray chest. Considering subgroups, 45.8% patients in the AV block group had cardiomegaly, whereas 40% patients in the SSS group and 33% in the trifascicular group had cardiomegaly. In the study conducted by Penton et al., [7] cardiomegaly was noted in 62.5% of patients. In the present study, three-fourths of our patients had normal left ventricular systolic function, whereas only around 10% of patients had moderate to severe left ventricular systolic dysfunction.

The only effective treatment for symptomatic bradycardia is permanent cardiac pacing. In the present study, 70.3% patient underwent the VVIR type of pacemaker implantation. The DDDR type of pacemaker was implanted in 29.7% of patients who were in the CHB group. Many of our patients with CHB underwent VVIR pacemaker implantation because of financial constraints. It may be noted that Chauhan et al. [18] performed a study on a total of 2019 patients who underwent new pacemaker implantation, and of the total, 1733 patients (85.8%) received a VVI pacemaker and 286 (14.2%) a DDD pacemaker. Following permanent pacemaker implantation, there was dramatic improvement in the symptoms of the patients. There was no further episode of syncopal attack in any of the patients; lightheadedness subsided; and conditions of dyspnea and fatigue improved considerably in all the patients. Palpitation was still persistent in 4 patients, of whom 3 had brady-tachy syndrome. Palpitation in these patients was controlled by the usage of oral antiarrhythmic drugs for controlling tachycardia.

We studied early complication after pacemaker implantation, i e, complications occurring within 6 weeks of pacemaker implantation. In our study population, only 2 patients had any complication. One patient had pneumothorax and another had pacemaker site wound exudation. The patient who was undergoing dual-chamber pacemaker insertion had pneumothorax. This patient did not have any symptoms, and x-ray chest was suggestive of minimal pneumothorax (<10% of the pulmonary field in the chest x-ray film). The patient was treated conservatively. In the study by Aggarwal et al. [19] of 1088 patients, pneumothorax complication represented an overall rate of 1.9% of subclavian insertions. Wound infection was suspected in 1 patient of VVIR pacemaker implant, as the patient had exudative discharge from pacemaker implant site incision on the third postoperative day. However, the pus culture was sterile. There were no deaths observed as a complication of pacemaker implantation in the present study. Chauhan et al. [18] performed a study to compare the frequency of early complications after single-chamber versus dual-chamber permanent pacemaker implantation. In his study, wound infection occurred in 11 (0.6%) VVI patients and 6 (2.1%) DDD patients.


  Conclusion Top


A total of 37 patients underwent pacemaker implantation, of whom around 90% were suffering from either CHB or SSS. Almost all patients were symptomatic and these symptoms were attributed to bradyarrhthymias. The bradyarrhythmias affected the older age group more than the younger age group. Clinical manifestations of symptomatic bradycardia are diverse, but the most dramatic presentation is syncopal attacks (Stokes-Adams syncope). After pacemaker implantation for symptomatic bradyarrhthymia, there was significant improvement in symptoms and quality of life. Therefore, we conclude that pacemaker implantation is the only effective and safe treatment available with relatively very few complications for patients with symptomatic bradyarrhthymia.

 
  References Top

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Ozcan KS, Osmonov D, Erdinler I, Altay S, Yildirim E, Turkkan C, et al. Atrioventricular block in patients with thyroid dysfunction: Prognosis after treatment with hormone supplementation or antithyroid medication. J Cardiol 2012;60:327-32.   Back to cited text no. 14
    
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  [Table 1], [Table 2], [Table 3]



 

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