MYBPH acts as modifier of cardiac hypertrophy in hypertrophic cardiomyopathy (HCM) patients.

Left ventricular hypertrophy is a risk factor for cardiovascular morbidity and mortality. Hypertrophic cardiomyopathy (HCM) is considered a model disease to study causal molecular factors underlying isolated cardiac hypertrophy. However, HCM manifests with various clinical symptoms, even in families bearing the same genetic defects, suggesting that additional factors contribute to hypertrophy. The gene encoding the cardiac myosin binding protein C (cMYBPC) is one of the most frequently implicated genes in HCM. Recently another myosin binding protein, myosin binding protein H (MYBPH) was shown to function in concert with cMYBPC in regulating cardiomyocyte contraction. Given the similarity in sequence, structure and the critical role MYBPH plays in sarcomere contraction, we proposed that MYBPH may be involved in HCM pathogenesis. Family-based genetic association analysis was employed to investigate the contribution of MYBPH in modifying hypertrophy. Seven single nucleotide polymorphisms and haplotypes in MYBPH were investigated for hypertrophy modifying effects in 388 individuals (27 families), in which three unique South African HCM-causing founder mutations (p.R403W and pA797T in ß-myosin heavy chain gene (MYH7) and p.R92W in the cardiac troponin T gene (TNNT2)) segregate. We observed a significant association between rs2250509 and hypertrophy traits in the p.A797T MYH7 mutation group. Additionally, haplotype GGTACTT significantly affected hypertrophy within the same mutation group. MYBPH was for the first time assessed as a candidate hypertrophy modifying gene. We identified a novel association between MYBPH and hypertrophy traits in HCM patients carrying the p.A797T MYH7 mutation, suggesting that variation in MYBPH can modulate the severity of hypertrophy in HCM.

European Society of Hypertension practice guidelines for home blood pressure monitoring.

Self-monitoring of blood pressure by patients at home (home blood pressure monitoring (HBPM)) is being increasingly used in many countries and is well accepted by hypertensive patients. Current hypertension guidelines have endorsed the use of HBPM in clinical practice as a useful adjunct to conventional office measurements. Recently, a detailed consensus document on HBPM was published by the European Society of Hypertension Working Group on Blood Pressure Monitoring. However, in daily practice, briefer documents summarizing the essential recommendations are needed. It is also accepted that the successful implementation of clinical guidelines in routine patient care is dependent on their acceptance by involvement of practising physicians. The present document, which provides concise and updated guidelines on the use of HBPM for practising physicians, was therefore prepared by including the comments and feedback of general practitioners.

[Physiopathology of the autonomic nervous system activity during sleep]. / Fisiopatologia dell'attività del sistema nervoso autonomo durante il sonno.

Sleep consists of two phases that periodically alternate: the rapid eye movement (REM) phase and the non-REM phase. The non-REM stage is characterized by wide synchronous waves in the electroencephalogram, by a low heart rate and by a decrease in arterial blood pressure and peripheral resistances. This hemodynamic setting is the consequence of the autonomic balance characterized by high vagal activity and low sympathetic activity. Such an autonomic condition is adequately described by the spectral analysis of heart rate variability documenting a prevalence in the high frequency band (the respiratory vagal band). The REM stage of sleep is characterized by asynchronous waves in the electroencephalogram and it is associated with a further increase in the vagal dominance of the autonomic balance resulting in a lower heart rate and decreased peripheral resistances. The REM phase of sleep is, however, also characterized by hemodynamic instability due to sudden bursts of sympathetic activity, associated with the rapid eye movements. These sympathetic bursts cause sudden changes in heart rate and peripheral resistance and may influence cardiac electrical stability both at the atrial and ventricular levels. Additionally, REM sleep may enhance the risk of anginal attacks in coronary artery disease patients. Analysis of the autonomic balance during the different phases of sleep may also help in the identification of autonomic derangements typically associated with myocardial infarction.