Heart rate variability - a review

Heart rate variability [HRV] is a measure of the balance between sympathetic mediators of heart rate that is the effect of epinephrine and norepinephrine released from sympathetic nerve fibres acting on the sino-atrial and atrio-ventricular nodes which increase the rate of cardiac contraction and facilitate conduction at the atrio-ventricular node and parasympathetic mediators of heart rate that is the influence of acetylcholine released by the parasympathetic nerve fibres acting on the sino-atrial and atrio-ventricular nodes leading to a decrease in the heart rate and a slowing of conduction at the atrio-ventricular node. Sympathetic mediators appear to exert their influence over longer time periods and are reflected in the low frequency power[LFP] of the HRV spectrum [between 0.04Hz and 0.15 Hz].Vagal mediators exert their influence more quickly on the heart and principally affect the high frequency power [HFP] of the HRV spectrum [between 0.15Hz and 0.4 Hz]. Thus at any point in time the LFP:HFP ratio is a proxy for the sympatho- vagal balance. Thus HRV is a valuable tool to investigate the sympathetic and parasympathetic function of the autonomic nervous system. Study of HRV enhance our understanding of physiological phenomenon, the actions of medications and disease mechanisms but large scale prospective studies are needed to determine the sensitivity, specificity and predictive values of heart rate variability regarding death or morbidity in cardiac and non-cardiac patients

childhood asthma being treated appropriately

It was a descriptive study done in the department of Pediatrics, Jinnah Medical College hospital Karachi from October 2005 to September 2006. All children between 1 to12 years, diagnosed as asthma [on clinical grounds] were enrolled. Information regarding asthma severity and use of regular drugs in past 6 months was recorded in a pre-de-signed Proforma. Disease severity was classified according to GINA guidelines as intermittent and persistent. Persistent group was further subdivided into mild, moderate and severe categories. Treatment in accordance to GINA guidelines was considered as a standard therapy. A total of 150 patients were enrolled, out of which only 4.7% were of intermittent category while 95.3% were of persistent type [39.3% mild persistent, 44% moderate persistent and 12% severe persistent]. Patient in intermittent group were not on any regular long term medication. Seventy six percent of the patients with persistent asthma were on quick relief drugs, while controller drugs were being used in19.3% cases only. Limited use of inhalers with or with out spacer device and nebulizers was observed [14% cases]. Inappropriate drugs according to GINA guidelines, e.g.: antihistamines, cough and cold preparations, mast cell stabilizers and drugs from hakims and homeopaths, were not included in the study results. Majority of the patients was not found to be treated according to GINA guidelines. Controller medications were being under prescribed while in its place reliever medication was being inappropriately advised on regular basis

Asymptomatic bacteriuria in pregnancy: assessment of frequency and risk factors

To determine the frequency and risk factors of asymptomatic bacteriuria during pregnancy. Hospital based cross sectional study. This study was undertaken at outpatient department of Obstetrics and Gynecology at Jinnah Medical College Hospital Karachi from May 1, 2008 till September 30, 2008. Two hundred pregnant women who met the inclusion criteria were included in the study after informed consent and evaluated for bacteriuria. Data collected was analyzed utilizing statistical programme for social sciences [SPSS] version 10. Out of Two hundred antenatal mothers screened, 12 had significant bacteriuria giving frequency of 6%. Out of them 3 [7.8%] patients were below 20 years, 7[5.78%] were between 20 and 30 years and 2 [4.87%] women were aged above 30 years [p=0.842]. Regarding parity 3[4%] primigravida and 9[7.2%] multigravida had asymptomatic bacteriuria [p=0.275]. It was observed that prevalence was highest, 9% in lower socioeconomic class as compared to 2.24% in lower middle and upper middle class. The difference was found to be statistically significant [p=0.041].Regarding education status 10.97% of women were uneducated and only 2.54% were educated [p=0.016]. The study revealed high incidence in [58.33%] in women with previous history of urinary tract infection [p=0.000]. The frequency of asymptomatic bacteriuria among pregnant women was 6%. It was associated with lower socioeconomic status, illiteracy and past history of urinary tract infection

Frequency of hepatitis B and C virus among the healthy volunteer blood donors at Taulka hospital Sujjawal, district Thatta, Sindh

To find out the prevalence of hepatitis B and C virus among the healthy volunteer blood donors at Taulka hospital Sujjawal, district Thatta Sindh. It was hospital based Cross Sectional study carried out from August 2004 to May 2005 at Taulka hospital Sujjawal, district Thatta. Sindh All healthy volunteer blood donors reporting to Blood bank were screened for Hepatitis B and C. The donors screening for HBsAg and Anti HCV is done by One Step Test Device [Serum / Plasma]. A total number of 310 donors were screened for HBsAg and HCV. The overall HBsAg prevalence was 5.81% and anti-HCV prevalence was 1.3%. Females [6.25%] are predominantly seropositive for HBsAg than males [5.76%] and regarding anti-HCV only males [1.3%] are seropositive in this study. Blood transfusion is one of the main sources of transmission of Hepatitis B and C. The preventive strategies are adopted for Hepatitis B and C viruses which constitute a major public health measures in Pakistan