Anti-arrhythmic properties of non-antiarrhythmic medications.

Traditional anti-arrhythmic drugs are classified by the Vaughan-Williams classification scheme based on their mechanisms of action, which includes effects on receptors and/or ion channels. Some known anti-arrhythmic drugs do not perfectly fit into this classification scheme. Other medications/molecules with established non-anti-arrhythmic indications have shown anti-arrhythmic properties worth exploring. In this narrative review, we discuss the molecular mechanisms and evidence base for the anti-arrhythmic properties of traditional non-antiarrhythmic drugs such as inhibitors of the renin angiotensin system (RAS), statins and polyunsaturated fatty acids (PUFAs). In summary, RAS antagonists, statins and PUFAs are 'upstream target modulators' that appear to have anti-arrhythmic roles. RAS blockers prevent the downstream arrhythmogenic effects of angiotensin II - the main effector peptide of RAS - and the angiotensin type 1 receptor. Statins have pleiotropic effects including anti-inflammatory, immunomodulatory, modulation of autonomic nervous system, anti-proliferative and anti-oxidant actions which appear to underlie their anti-arrhythmic properties. PUFAs have the ability to alter ion channel function and prevent excessive accumulation of calcium ions in cardiac myocytes, which might explain their benefits in certain arrhythmic conditions. Clearly, whilst a number of anti-arrhythmic drugs exist, there is still a need for randomised trials to establish whether additional agents, including those already in clinical use, have significant anti-arrhythmic effects.

Lesson of the month 1: Case reports of arrhythmogenic cardiomyopathies in military personnel.

In military recruits, sudden cardiac death rates have been reported as varying from 2 to 13 per 100,000 per year which are mostly related to exercise. However, the development of structural heart changes that may be associated with ventricular arrhythmias have not been reported among this cohort, despite them undergoing endurance training similar to athletes. Here, we report two cases where military personnel were found to have life-threatening cardiac arrhythmias associated with structural heart disease, highlighting the importance of early recognition and treatment of these arrhythmias.

ACE inhibition to slow progression of myocardial fibrosis in muscular dystrophies.

Muscular dystrophy (MD) connotes a heterogeneous group of inherited disordersaffecting skeletal and cardiac muscle. Inseveral forms of MD, the cardiac disease may be the predominant manifestationof the underlying genetic myopathy. The cardiacinvolvement is due to progressive interstitial fibrosis and fatty replacement inboth the atria and ventricles, which may lead to cardiomyopathy, conductiondefects and tachyarrhythmias. Angiotensin-convertingenzyme inhibitors (ACE-Is) modulate the production of angiotensin II and limitthe amount of fibrosis in the myocardium, reducing mortality andhospitalization in cardiac patients. The aim of present review is to describethe antifibrotic proprieties of ACE inhibitor therapy and to summarize thecurrent body of scientific literature relating to the use of ACE-Is for theprevention and treatment of cardiomyopathy in patients with musculardystrophies.

Anticipating policy considerations for a future HIV vaccine: a preliminary study.

BACKGROUND: New human immunodeficiency virus (HIV) infections continue to occur worldwide. Despite previous failures, there is renewed optimism about developing an efficacious HIV prophylactic vaccine following the 31.2% vaccine efficacy (modified intention to treat analysis) achieved in the RV-144 trial. Intense efforts at characterising the immune responses in the trial participants who appeared to gain some protection from the candidate vaccine are ongoing to delineate correlates of protection. However, the characteristics of a vaccine suitable for programmatic introduction in high prevalence areas remain undefined. AIMS: We set out to ascertain the vaccination policies and strategies that policy makers involved in vaccine introductions would advise were a candidate HIV vaccine to become available. METHODS: Structured questionnaires in both English and French were self-administered to consenting policy makers such as members of National Immunisation Technical Advisory Groups. Members from three out of the six WHO regional groups were purposively reached for their responses. RESULTS: Thirty-seven key opinion leaders were approached through self-administered questionnaires delivered by e-mail or in person. Nine responses were received, representing a 24.3% response rate. The responses received were from three [Africa (6), Americas (1) and Europe (2)] out of the six WHO regions. All respondents would prioritise the vaccination of commercial sex workers over other risk groups if there was an efficacious HIV vaccine. Vaccine efficacy was considered to be the most important factor, ahead of vaccine safety and cost, in determining the acceptability of a new prophylactic HIV vaccine. CONCLUSIONS: It is expected that the first generation HIV vaccines may be modestly efficacious. However, even a modestly efficacious vaccine might curtail the spread of HIV if universal or near-universal coverage is achieved. It is important to anticipate policy discussions which would influence how rapidly an HIV vaccine would be rolled-out programmatically to achieve maximum impact.

The burden and correlates of hypertension in rural Ghana: a cross-sectional study.

AIM: Cardiovascular diseases (CVDs), of which hypertension is a major risk factor, are predicted to account for four times as many deaths as from communicable diseases by the year 2020. Hypertension, once rare, is rapidly becoming a major public health burden in sub-Saharan Africa (SSA). However, data on its prevalence, awareness, treatment and control are paltry, especially for rural communities. This study was done to determine the burden and correlates of adult hypertension in the rural Barekese sub-district of Ghana. METHODS: A cross-sectional survey was conducted on 425 adults aged ≥ 35 in the Barekese sub district (estimated population 18,510). Socio-demographic characteristics, modifiable and non-modifiable risk factors, blood pressure (BP) and anthropometric measurements were collected using standardized protocols. RESULTS: Overall, the proportion of hypertension and isolated systolic hypertension is 44.7% and 32.7% respectively in the study population. However, 64.9% of these were on treatment, with only 8.9% having controlled blood pressure (<140/90 mmHg). The mean systolic and diastolic BP were 134.38 mmHg (standard deviation, SD: 21.46) and 84.32 mmHg (SD: 12.44). Obesity (Body Mass Index, BMI>30 kg/m²) was found in 37 (10.4% of the population), out of whom 7 (15.9%) were extremely obese (BMI> 40 kg/m²). Increasing age and level of education were positively correlated with increasing blood pressure. CONCLUSION: The high burden of hypertension in this population along with the considerable less detection, treatment and control is of great concern. There is the need to promote health education measures that will foster prevention and early detection of hypertension.