Sympathetic activation in heart failure.

Sympathetic activation has been long appreciated exclusively as a fundamental compensatory mechanism of the failing heart and, thus, welcome and to be supported. In the initial clinical phases of heart failure (HF), the sympathetic nervous system overdrive plays a compensatory function aimed at maintaining an adequate cardiac output despite the inotropic dysfunction affecting the myocardium. However, when the sympathetic reflex response is exaggerated it triggers a sequence of unfavourable remodelling processes causing a further contractile deterioration that unleashes major adverse cardiovascular consequences, favouring the HF progression and the occurrence of fatal events. Eventually, the sympathetic nervous system in HF was demonstrated to be a 'lethality factor' and thus became a prominent therapeutic target. The existence of an effective highly specialized intracardiac neuronal network immediately rules out the old concept that sympathetic activation in HF is merely the consequence of a drop in cardiac output. When a cardiac damage occurs, such as myocardial ischaemia or a primary myocardial disorder, the adaptive capability of the system may be overcame, leading to excessive sympatho-excitation coupled with attenuation till to abolishment of central parasympathetic drive. Myocardial infarction causes, within a very short time, both a functional and anatomical remodelling with a diffuse up-regulation of nerve growth factor (NGF). The subsequent nerve sprouting signal, facilitated by a rise in the levels of NGF in the left stellate ganglion and in the serum, triggers an increase in cardiac nerve density in both peri-infarct and non-infarcted areas. Finally, NFG production decreases over time, supposedly as an adaptative response to the prolonged exposure to sympathetic overactivity, leading in the end to a reduction in sympathetic nerve density. Accordingly, NGF levels were markedly reduced in patients with severe congestive heart failure. The kidney is the other key player of the sympathetic response to HF as it indeed reacts to under-perfusion and to loop diuretics to preserve filtration at the cost of many pathological consequences on its physiology. This vicious loop ultimately participates to the chronic and disruptive sympathetic overdrive. In conclusion, sympathetic activation is the natural physiological consequence to life stressors but also to any condition that may harm our body. It is the first system of reaction to any potential life-threatening event. However, in any aspect of life over reaction is never effective but, in many instances, is, actually, life threatening. One for all is the case of ischaemia-related ventricular fibrillation which is, strongly facilitated by sympathetic hyperactivity. The take home message? When, in a condition of harm, everybody is yelling failure is just around the corner.

Beneficial effects of adaptive servo-ventilation on natriuretic peptides and diastolic function in acute heart failure patients with preserved ejection fraction and sleep-disordered breathing.

PURPOSE: Adaptive servo-ventilation (ASV) is a ventilator algorithm able to correct breathing through anticyclic support of breathing in patients with central sleep apnea (CSA). So far, very few data exist regarding the role of ASV on acute heart failure with preserved ejection fraction (HFpEF). METHODS: We performed a single-center prospective, randomized, case-control study in consecutive acute HFpEF (left ventricle ejection fraction, LVEF ≥ 45%) patients with sleep-disordered breathing (SDB, apnea-hypopnea index, AHI > 15/h) and prevalence of CSA. RESULTS: We included ten consecutive patients randomized for ASV on top of standard therapy for acute heart failure (group 1) versus standard care alone (group 2). ASV therapy significantly reduced AHI and CSA. An improvement in cardiac diastolic function was seen in group 1 compared to group 2 (E/E' 17.5 to 9.6, p < 0.02 vs 18.5 to 14.5, p = 0.4). Brain natriuretic peptide (BNP) markedly decreased in cases, but not in controls (298 to 84 pg/ml, p < 0.02 vs 280 to 120 pg/ml, p = 0.06). Right ventricle (RV) function significantly improved in group 1, differently from group 2. CONCLUSIONS: An acute use of ASV seems effective in reducing BNP and improving diastolic and RV function in acute HFpEF patients with SDB and CSA, compared to standard treatment.

Global Longitudinal Strain in master athletes and in hypertensive patients with the same degree of septal thickness.

Athletes may have electrocardiogram (ECG) repolarization abnormalities during stress test suggestive for ischemia in the absence of ischemic coronary artery disease, often in a setting of myocardial septum hypertrophy. Global longitudinal strain (GLS) might be altered in these athletes compared to hypertensive patients with the same degree of septal thickness. About 735 consecutive athletes were screened for mandatory assessment of fitness to participate in competitive sports. At the stress test, 23 (19 M, 4 F) were found to have ECG repolarization abnormalities suggestive for ischemia in the presence of normal coronary vessels. They were matched to a control group of 23 hypertensive patients with no ECG abnormalities during stress test and the same degree of septal thickness. A transthoracic echocardiography for evaluation of global longitudinal strain (GLS) was performed. Interventricular septum thickness (IST) and relative wall thickness (RWT) were also calculated. A preserved ventricular function was seen in both groups (64 ± 8% in cases vs 60 ± 6% in controls, P = 0.42). IST and RWT were not significantly different. GLS was significantly lower in athletes vs hypertensive patients (-18.7 ± 2.5 vs -21.67 ± 0.27, P = 0.001). In athletes with septal hypertrophy and a positive stress test not associated to coronary disease, GLS is lower with respect to a population of hypertensive patient with the same degree of septal hypertrophy. Further investigations in a larger population are required to better define the potentiality of GLS in differentiating pathological vs physiological septum hypertrophy.

First Report of a Successful Pregnancy in an Everolimus-Treated Heart-Transplanted Patient: Neonatal Disappearance of Immunosuppressive Drugs.

The use of everolimus (EVL) as primary immunosuppression is steadily increasing in heart transplantation (HTx) patients. Limited data currently exist in kidney transplantation, but there is no report of EVL use during pregnancy after HTx and its pharmacokinetics in the newborn. We report a case of an unplanned pregnancy discovered at 21 weeks of gestation in a female HTx patient aged 40 years treated with EVL and cyclosporine (CyA). Because pregnancy was advanced, immunosuppression therapy was left unchanged. At 36 weeks, a healthy infant was delivered. At birth, CyA blood levels were lower in the neonate, but EVL concentrations in maternal and neonatal umbilical blood were similar. Amniotic fluid concentrations were undetectable for both drugs. In the newborn, EVL was measurable at 5 days after birth, whereas CyA disappeared within 2 days. Cord blood displayed a normal count of B and T cells and CD4, CD8 and natural killer cell populations. At birth, both mother and newborn displayed the same blood levels of EVL; therefore, a filter effect of the placenta may be hypothesized for CyA but not for EVL. No immediate complications were observed with this pregnancy.