NT-proBNP: When is it useful in Obstetric Medicine?

Pregnancy, viewed as a stress test of the haemodynamic system, may unmask underlying cardiac disease. Pregnancy may also induce de novo cardiac disease. N-terminal pro brain-type natriuretic peptide (NT-proBNP) is a useful biomarker in all clinical conditions in which the ventricle is stressed and especially stretched in the general population. In hypertensive diseases of pregnancy, increased levels of NT-proBNP in preeclampsia are associated with increased cardiac filling pressures and diastolic dysfunction. Increased levels of NT-proBNP in pregnant women with known cardiac disease may lead to earlier diagnosis of impending heart failure. Similarly, elevated levels of NT-proBNP assist with the diagnosis of peripartum cardiomyopathy and are increasingly used in follow-up. Women with known congenital heart disease who are pregnant can be screened for risk of cardiac events such as heart failure by the use of NT-proBNP levels. There is a paucity of data in pregnancy with the use of NT-proBNP and more research is needed.

Rheumatoid arthritis and risk of cardiovascular disease.

In developing countries, rheumatoid arthritis (RA) remains a seriously under-prioritised disease, particularly among the underprivileged, often resulting in presentation of patients late in the course of their disease, further complicated by limited therapeutic options and inconsistent follow up. The consequences are often severe with irreversible disability, increased frequency of co-morbidities, especially cardiovascular disease (CVD), and higher mortality rates, relative to developed countries. Despite addressing traditional cardiovascular risk factors, the impact of subclinical or 'residual' inflammation from uncontrolled RA needs to be considered. This narrative review explores the prevalence and pathogenesis of CVD in RA, including the impact of tobacco use. It discusses pitfalls in the risk assessment of CVD in patients with RA, and the effect of disease-modifying anti-rheumatic therapy on cardiovascular co-morbidity.

Aortic Arch Baroreceptor Stimulation in an Experimental Goat Model: A Novel Method to Lower Blood Pressure.

The effect of aortic baroreceptor stimulation on blood pressure manipulation was assessed using the goat species Capra aegagrus hircus. The aim of this study was to manipulate blood pressure with future intention to treat high blood pressure in humans. The ages of the animals ranged from 6 months to 2 years. A standard anesthesia protocol was used. A lateral thoracotomy was performed to gain access to the aortic arch. Data was collected with the Vigileo system. Pre stimulation blood pressure was compared with maximum post stimulation blood pressure values. Results were analyzed with the Wilcoxon signed rank test. In the study 38 animals were enrolled. Baroreceptor stimulation was performed for each animal using 3 different electrodes each of which emits an electrical impulse. In the pilot phase of the study, the median baseline blood pressure prior to stimulation of the baroreceptors was 110.8 mmHg. After stimulation the median blood pressure decreased to 88 mmHg. The average decrease in blood pressure was 22.8 mmHg. This decrease of blood pressure after stimulation of the baroreceptors is statistically significant (p < 0.0001) and the proof of concept was shown. During the extended phase all three probes had a significant effect on blood pressure lowering (p < 0.0001). The study confirmed that aortic baroreceptor stimulation has an effect on blood pressure lowering. This is a novel field of blood pressure manipulation. The hemodynamic effects of long-term aortic baroreceptor stimulation are unknown. Further investigations need to be done to determine whether a similar effect can be induced in different species such as primates and humans.

Non-acid gastro-oesophageal reflux is associated with squamous cell carcinoma of the oesophagus.

INTRODUCTION: Squamous cell carcinoma of the oesophagus is a common cancer among South Africans. Due to the absence of effective screening and surveillance programme for early detection and late presentation, squamous cell carcinoma of the oesophagus is usually diagnosed at an advanced stage or when metastasis has already occurred. The 5-year survival is often quoted at 5%-10%, which is poor. OBJECTIVES: To determine the association between oesophageal squamous cell carcinoma (OSCC) and non-acid gastro-oesophageal reflux disease. METHODS: Study design: A cross-sectional case-control analytical study of patients referred to the Gastroenterology Division of Steve Biko Academic Hospital in Pretoria, South Africa. All patients had combined multichannel impedance and pH studies done and interpreted after upper gastroscopy using the American College of Gastroenterology guidelines by two clinicians. RESULTS: Thirty-two patients with OSCC were recruited: non-acid reflux was found in 23 patients (73%), acid reflux in 2 patients (6%) and 7 patients (22%) had normal multichannel impedance and pH studies.Forty-nine patients matched by age, gender and race were recruited as a control group. Non-acid reflux was found in 11 patients (22%), acid reflux in 31 patients (63%) and 7 patients (14%) had normal multichannel impedance and pH monitoring study. CONCLUSION: The significance of the association between non-acid reflux and OSCC was tested using χ2, and simple logistic regression was used to adjust for the effects of potential confounders.The OR of developing OSCC in patients with non-acid gastro-oesophageal reflux was 8.8 (95% CI 3.2 to 24.5, P<0.0001) in this South African group.Alcohol and smoking had no effect on these results.

Effect of exercise on cardiac autonomic function in females with rheumatoid arthritis.

The objective of this study is to evaluate the effect of exercise on cardiac autonomic function as measured by short-term heart rate variability (HRV) in females suffering from rheumatoid arthritis (RA). Females with confirmed RA were randomly assigned to an exercise group (RAE) and a sedentary group (RAC). RAE was required to train under supervision two to three times per week, for 3 months. Three techniques (time domain, frequency domain and Poincaré plot analyses) were used to measure HRV at baseline and study completion. At baseline, RAC (n = 18) had a significantly higher variability compared to RAE (n = 19) for most HRV indicators. At study completion, the variables showing significant changes (p = 0.01 to 0.05) favoured RAE in all instances. Wilcoxon signed rank tests were performed to assess changes within groups from start to end. RAE showed significant improvement for most of the standing variables, including measurements of combined autonomic influence, e.g. SDRR (p = 0.002) and variables indicating only vagal influence, e.g. pNN50 (p = 0.014). RAC mostly deteriorated with emphasis on variables measuring vagal influence (RMSSD, pNN50, SD1 and HF (ms(2)). Study results indicated that 12 weeks of exercise intervention had a positive effect on cardiac autonomic function as measured by short-term HRV, in females with RA. Several of the standing variables indicated improved vagal influence on the heart rate. Exercise can thus potentially be used as an instrument to improve cardiac health in a patient group known for increased cardiac morbidity.

Autonomic impairment in rheumatoid arthritis.

AIM: To determine if there is a difference between autonomic cardiac control as measured by heart rate variability (HRV) in women with rheumatoid arthritis (RA) compared to a healthy control group. METHODS: The RA group (45) and control group (39) were matched for age and body mass index (BMI). Three techniques were used: time domain, frequency domain and Poincarè plot analysis. All possible confounding factors were excluded and the test environment strictly regulated. RESULTS: Basal heart rate was significantly higher in the RA patients. In the supine position significant differences existed between RA patients and controls (P ≤ 0.01). Indicators of parasympathetic activity showed significantly lower variation in the RA group (root mean square of the standard deviation [RMSSD] = 14.70, percentage of successive normal-to-normal interval differences larger than 50 ms [pNN50] = 0.50, standard deviation [SD]1 = 10.50, high frequency [HF] (ms(2)) = 31) compared to controls (RMSSD = 29.40, pNN50 = 7.8, SD1 = 20.9, HF (ms(2)) = 141.00). Indicators of sympathetic variation were also significantly lower in RA patients (SD2 = 36.70, low frequency [LF] (ms(2)) = 65) compared to controls (SD2 = 49.50, LF (ms(2)) = 175). In the standing position eight variables indicated autonomic impairment by significant differences (P ≤ 0.01) between the groups. The response of the RA group to an orthostatic stressor showed less vagal withdrawal, (P-values for RMSSD = 0.038, pNN50 = 0.022, SD1 = 0.043 and HF [ms(2) ] = 0.008 respectively); and lower sympathetic response (P-values for SD2 = 0.001 and LF [ms(2) ] < 0.001) when compared to controls. CONCLUSIONS: An inability of the autonomic nervous system to efficiently compensate for internal and external environmental changes may predispose RA patients to arrhythmias, thereby increasing cardiovascular mortality. All three methods used showed the same outcome, implying decreased HRV and thus an increased risk for arrhythmias in RA patients. Evaluating the autonomic nervous system might be critical in planning management of RA patients.

Carboxyhaemoglobin levels in water-pipe and cigarette smokers.

UNLABELLED: Water-pipe smoking is growing in popularity, especially among young people, because of the social nature of the smoking session and the assumption that the effects are less harmful than those of cigarette smoking. It has however been shown that a single water-pipe smoking session produces a 24-hour urinary cotinine level equivalent to smoking 10 cigarettes per day. AIM: We aimed to measure carboxyhaemoglogin (COHb) blood levels before and after water-pipe and cigarette smoking sessions. METHOD: Self-confessed smokers older than 18 years (N=30) volunteered to smoke a water-pipe or a cigarette and have their blood COHb levels measured under controlled conditions. RESULTS: Mean baseline COHb levels were 2.9% for the 15 cigarette smokers and 1.0% for the 15 water-pipe smokers. Levels increased by a mean of 481.7% in water-pipe smokers as opposed to 39.9% in cigarette smokers. CONCLUSION: The study demonstrated that water-pipe smokers had significantly higher increases in blood COHb levels than cigarette smokers during a single smoking session.

Hypertension and Sexual Dysfunction

Hypertension is a major independent cardiovascular risk factor; and also a marker of survival risk. Quality of life during the treatment of hypertension is an important health issue; as one in every five treated patients with hypertension will discontinue their therapy due to sideeffects.1 Discontinuation of therapy; and poor compliance with therapy; will eventually lead to a poorer outcome. The appearance of treatment-related side- effects may actually make patients feel worse than they did prior to treatment; when most hypertensive patients are asymptomatic. Sexual dysfunction is a potential side-effect of therapy; and may lead to poor therapy compliance

Angiotensin II Type 1 Receptor Antagonists and their Combinations in the Treatment of Hypertension

The pathophysiology of hypertension is not multifactorial in nature; and there is a complex interplay of mechanisms of control and counter-regulatory responses activated by drugs. The problem for clinicians is that it is not really possible to recognise the various clinical phenotypes of hypertension. In other words; the heterogeneity of hypertension remains a clinical problem.1 Current overwhelming evidence is that the most important treatment concept in the management of hypertension is that treatment should reduce blood pressure to goal levels.2 The majority of hypertensive patients will need two or more antihypertensive drugs to control their blood pressure at goal. Conceptually; a strong case can be made for the early use of combination therapy in the treatment of hypertension.3

Beta Blockers and their Combinations in the Management of Hypertension

Beta blockers have been prescribed for the treatment of primary hypertension for a very long time. Currently; it is doubtful whether this is still a good idea. In fact; many are of the opinion that beta blockers should be relegated to a fourth-line drug; if used at all; for the treatment of hypertension. So what happened? Why the change of heart? Basically; two issues are driving this new view of beta blockers.Firstly; beta blockers are cardioprotective when given to patients with a recent myocardial infarction and reduce subsequent mortality significantly. Certain types of beta blockers reduce mortality in patients with heart failure. This efficacy in secondary protection was translated to primary prevention without a critical assessment; and this is particularly the case in hypertension.Secondly; reducing blood pressure by any means may not automatically translate into reduced cardiovascular morbidity and mortality. This happened with beta blockers in the primary treatment of hypertension

Antihypertensive Treatment in the Elderly

Hypertension is a major risk factor for cardiovascular disease; but it is also very prevalent in the community. These two factors combined prompted the World Health Organization (WHO) to report that high blood pressure is the first cause of death worldwide.1 The prevalence of hypertension has been estimated to be approximately one in four; and this increases with age to such an extent that almost two-thirds of people over the age of 60 years have hypertension.2

Antihypertensive Treatment in the Elderly

Hypertension is a major risk factor for cardiovascular disease; but it is also very prevalent in the community. These two factors combined prompted the World Health Organization (WHO) to report that high blood pressure is the first cause of death worldwide.1 The prevalence of hypertension has been estimated to be approximately one in four; and this increases with age to such an extent that almost two-thirds of people over the age of 60 years have hypertension.2

Management Issues in Hypertensive Diabetics

Diabetes mellitus and hypertension are common clinical conditions that often co-exist. This combination has been called the deadly duet to emphasise the increased cardiovascular risk when the two conditions co-exist. Hypertension occurs more commonly in diabetics than in comparable non-diabetics; as the prevalence of hypertension in diabetics is about two times higher than that of hypertension as observed in the general population. In type 2 diabetes mellitus; hypertension is often present as part of a possible common underlying metabolic abnormality; such as insulin resistance. However; in type 1 diabetes mellitus; hypertension is often due to the onset of diabetic nephropathy

Hypertensive Crisis

Hypertension is a common medical problem. It affects approximately one in four adults worldwide; with evidence that the prevalence is rising. In the USA; approximately 30 of adults have some form of hypertension.1 It is estimated that 1-2 of the hypertensive population will present with an acute and severe elevation of blood pressure at some stage; i.e. hypertensive crisis: systolic blood pressure 180 mmHg; or diastolic blood pressure 120 mmHg.2

Hypertension

Approximately one in four adults has hypertension; a prevalence that increases with age and may reach to two out of three adults older than 70 years of age. In the Framingham Heart Study 65-75 of hypertension in the elderly is of the isolated systolic hypertension variety. Hypertension causes a two- to threefold increased risk of atherosclerotic cardiovascular events. Hypertension clusters with dyslipidaemia; insulin resistance; glucose intolerance and obesity in more than 80 of cases.1 The great majority of hypertensives thus have additional cardiovascular risk factors. The global cardiovascular risk; of which hypertension is but one component; is best appreciated by the use of risk charts such as the Framingham Risk Score