Die sesweke-ondersoek ná koronêre vatchirurgie: bevindinge by Bloemfontein Medi-Clinic Hospitaal

The six-week examination after coronary bypass surgery: findings at a Medi-Clinic Hospital in Bloemfontein. Background: Surgery provides symtomatic relief and improves the prognosis in patients with coronary artery disease. The general practitioner manages the postoperative patient. The aim of the study was to establish which symptoms and signs are present at the time of the six-week follow-up after coronary artery bypass graft surgery. Methods: A descriptive database search with a retrospective direction of enquiry was undertaken to establish the symptoms and signs experienced by patients six weeks after coronary artery bypass surgery (CABG). The patients were operated on by one surgeon in one hospital. The prevalence of readmissions, chest pain, angina, blood pressure, NYHA class, lung auscultation, wounds and medications were noted. Results: Records were available for 181 patients. However, only 158 patients were seen in the surgeon\'s rooms six weeks after surgery. Patients were also consulted before and after the six weeks, but usually in hospital. One patient died before her appointment and two patients did not return for follow-up. Fifteen (8.5%; 95% CI 4.9% to 13.7%) patients were readmitted to a hospital for a variety of reasons, Severe chest pain was present in 3.4% (95% CI 1.3% to 7.2%) patients. One patient had a myocardial infarction with patent grafts at cardiac catheterisation. Another two patients were investigated for possible angina, but it could not be proved. A total of 82.2% (95% CI 76.5% to 87.9%) of the patients were in NYHA I, whereas 3.5% (95% CI 1.3% to 7.4%) were class III, of whom two thirds were in class III before the operation. Hypertension was noticed in 70.1% of the patients (95% CI 62.9% to 77.2%). During auscultation of the lungs, abnormalities were picked up in 4.9% of the patients, while the sternum was not properly healed in 3.4% (95% VI 1.3% tot 7.2%). All the patients were on aspirin, but only 57% took an ACE inhibitor, 37% took a statin and 29% a beta-blocker.Conclusions:This study provides a picture of what to expect six weeks after a CABG.South African Family Practice Vol. 47(3) 2005: 61-6

The Cardiovascular Effects of a Meal: J-Tpeak and Tpeak -Tend Assessment and Further Insights Into the Physiological Effects.

Meal intake leads to a significant and prolonged increase in cardiac output to supply the splanchnic vasculature. A meal is associated with sympathetic activation of the cardiovascular system, and food ingestion is correlated with an increase in heart rate, an increase in cardiac stroke volume, and QTc interval shortening for up to 7 hours. Given the complexity of the system, one or several of many mechanisms could explain this observation. The shortening of the QTc interval was correlated with a rise of C-peptide following food ingestion, but the mechanisms by which C-peptide may be involved in the modulation of cardiac repolarization are still unknown. This shortening of the myocardial action potential caused by the ingestion of food was further investigated in the present study by measuring the QRS, J-Tpeak , and Tpeak -Tend intervals in search of further clues to better understand the underlying mechanisms. A retrospective analysis was conducted based on data collected in a formal thorough QT/QTc study in which 32 subjects received a carbohydrate-rich "continental" breakfast, moxifloxacin without food, and moxifloxacin with food. We assessed the effect of food on T-wave morphology using validated algorithms for measurement of J-Tpeak and Tpeak -Tend intervals. Our findings demonstrate that a standardized meal significantly shortened J-Tpeak for 4 hours after a meal and to a much lesser extent and shorter duration (up to 1 hour) prolonged the Tpeak -Tend and QRS intervals. This suggests that the QTc shortening occurs mainly during phase 2 of the cardiac action potential. As there was no corresponding effect on Tpeak -Tend beyond the first hour, we conclude that a meal does not interfere with the outward correcting potassium channels but possibly with Ca2+ currents. An effect on mainly Ca2+ aligns well with our understanding of physiology whereby an increase in stroke volume, as observed after a meal, is associated with changes in Ca2+ cycling in and out of the sarcoplasmic reticulum during cardiac myocyte contraction

Effects of the Fluoroquinolones Moxifloxacin and Levofloxacin on the QT Subintervals: Sex Differences in Ventricular Repolarization.

Women are associated with longer electrocardiographic QT intervals and increased proarrhythmic risks of QT-prolonging drugs. The purpose of this study was to characterize the differences in cardiac electrophysiology between moxifloxacin and levofloxacin in men and women and to assess the balance of inward and outward currents through the analysis of QT subintervals. Data from 2 TQT studies were used to investigate the impact of moxifloxacin (400 mg) and levofloxacin (1000 and 1500 mg) on QT subintervals using algorithms for measurement of J-Tpeak and Tpeak -Tend intervals. Concentration-effect analyses were performed to establish potential relationships between the ECG effects and the concentrations of the 2 fluoroquinolones. Moxifloxacin was shown to be a more potent prolonger of QT interval corrected by Fredericia (QTcF) and had a pronounced effect on J-Tpeak c. Levofloxacin had little effect on J-Tpeak c. For moxifloxacin, the concentration-effect modeling showed a greater effect for women on QTcF and J-Tpeak c, whereas for levofloxacin the inverse was true: women had smaller QTcF and J-Tpeak c effects. The different patterns in repolarization after administration of both drugs suggested a sex difference, which may be related to the combined IKs and IKr inhibitory properties of moxifloxacin versus IKr suppression only of levofloxacin. The equipotent inhibition of IKs and IKr appears to affect women more than men. Sex hormones are known to influence cardiac ion channel expression and differences in QT duration. Differences in IKr and IKs balances, influenced by sex hormones, may explain the results. These results support the impact of sex differences on the cardiac safety assessment of drugs

Failure to thrive and its relationship to serum vitamin A levels and diet

CITATION: Donald, P. R. et al. 1995. Failure to thrive and its relationship to serum vitamin A levels and diet. South African Medical Journal, 85:373-377.The original publication is available at http://www.samj.org.zaSerum vitamin A and retinol-binding protein (REP) levels were determined in a group of 34 children between 1 and 4 years of age with failure to thrive and in 34 age- and sex-matched controls. Both groups of children were also assessed in respect of anthropometry and diet. Vitamin A levels in patients (0-32,2 μg/100 ml; median 16,9 μg/100 ml) did not differ significantly from controls (6,4-47,2 μg/100 ml; median 16,1 μg/100 ml). Fourteen patients (42%) and 4 controls (12%) had vitamin A levels below 10 μg/100 ml. RBP levels in patients (0.45-3,50 mg/100 ml; median 2,17 mg/100 ml) also did not differ significantly from those in controls (1,21-3,66 mg/100 ml; median 2.06 mg/100 ml). No clinical features of vitamin A deficiency were detected. Weight and height for age, weight for height, mid-upper arm circumference and head circumference differed significantly between patients and controls (P < 0.0001 in each instance). Although within the recommendations for intake, patients had a significantly lower intake of the essential fatty acid C 18:2 (N=6) (linoleic acid) and vitamin A. In view of the current proposed relationship between vitamin A status and infectious diseases, the prevalence of biochemical vitamin A deficiency in children in the Cape Town community studied may contribute to the morbidity and mortality associated with infectious diseases in the area to a greater degree than has been suspected.Publisher’s versio

Two novel frameshift mutations in the low density lipoprotein receptor gene generated by endogenous sequence-directed mechanisms

DNA samples from 60 unrelated Belgian hypercholesterolemic patients were subjected to heteroduplex analysis of exon 4 of the low density lipoprotein receptor (LDLR) gene. Aberrant mobility bands were detected in 2 patients and the underlying mutations were characterized by DNA sequence analysis. Both mutations, a 19-bp insertion at codon 141 and a 23-bp deletion at codon 168, produce premature stop codons in the highly conserved ligand binding domain of the mature LDLR. Sequence data indicated that mispairing between short direct repeats during DNA replication is the most probable mechanism by which these mutations could have arisen. Our observations are consistent with an endogenous sequence-directed mechanism of mutagenesis.Articl