A new oscillometric method for pulse wave analysis: comparison with a common tonometric method.

In the European Society of Cardiology-European Society of Hypertension guidelines of the year 2007, the consequences of arterial stiffness and wave reflection on cardiovascular mortality have a major role. But the investigators claimed the poor availability of devices/methods providing easy and widely suitable measuring of arterial wall stiffness or their surrogates like augmentation index (AIx) or aortic systolic blood pressure (aSBP). The aim of this study was the validation of a novel method determining AIx and aSBP based on an oscillometric method using a common cuff (ARCSolver) against a validated tonometric system (SphygmoCor). aSBP and AIx measured with the SphygmoCor and ARCSolver method were compared for 302 subjects. The mean age was 56 years with an s.d. of 20 years. At least two iterations were performed in each session. This resulted in 749 measurements. For aSBP the mean difference was -0.1 mm Hg with an s.d. of 3.1 mm Hg. The mean difference for AIx was 1.2% with an s.d. of 7.9%. There was no significant difference in reproducibility of AIx for both methods. The variation estimate of inter- and intraobserver measurements was 6.3% for ARCSolver and 7.5% for SphygmoCor. The ARCSolver method is a novel method determining AIx and aSBP based on an oscillometric system with a cuff. The results agree with common accepted tonometric measurements. Its application is easy and for widespread use.

[Circadian rhythm of silent myocardial ischemia. Why morning is so risky for hypertensive patients]. / Zirkadiane Rhythmik der stummen Myokardischämie. Warum der Morgen für Hypertoniker so gefährlich ist.

The circadian pattern of numerous cardiovascular events (myocardial infarction, sudden cardiac death, stroke) reveals a peak in the early hours of the morning. A circadian rhythm peaking in the morning is also found for so-called silent myocardial ischaemia, which occurs in more than 20% of patients with arterial hypertension, and can be regularly detected in combined 24-h-ABPM/EKG examinations. Comparative studies have shown that hypertensives with SMI suffer more cardiac events than those with no SMI. It has further been demonstrated that an elevated blood pressure amplitude, with is considered an independent risk factor for cardiac events, is associated with an increased incidence of SMI in patients with micro- or macro-angiopathy. Accordingly, consideration should be given to SMI when deciding on treatment, also in hypertensives with no angina pectoris symptoms.

[Therapy resistant hypertension--significance of electronic compliance monitoring]. / Therapierefraktäre Hypertonie--Stellenwert von elektronischem "Compliance-Monitoring"

HISTORY AND CLINICAL FINDINGS: A 71-year-old woman was admitted with arterial hypertension resistant to drug therapy (office readings 197/82 mmHg) under medication with beta-blocker, AT 1 -antagonist and a diuretic. The only physical pathologic finding was an adipositas. DIAGNOSIS, TREATMENT AND COURSE: The patient was suffering from isolated systolic hypertension, grade 3 corresponding to WHO-guidelines. Despite antihypertensive triple therapy office as well as self-measured blood pressure values (mean 170/82 mmHg) remained elevated. Thus, the patient fulfilled the criteria of a resistant hypertension. The degree of compliance was only 50 %, detected by using a Medication-Event-Monitoring-System (correct dosing interval 17.1 %). We discussed the results of compliance- and blood pressure self-measurement with the patient. In the following period of compliance- and blood pressure self-measurement (with unchanged antihypertensive therapy) the compliance increased dramatically with a degree of 90,9 % and self-measured blood pressure values almost normalized (mean 137/71 mmHg). CONCLUSION: The control of compliance by using electronic compliance-monitoring may help to discover non-compliance as a frequent cause of resistant hypertension and to avoid unnecessary cost-extensive procedures.

C-FOS expression in the rat brain in response to substance P and neurokinin B.

Substance P, the principal neurokinin peptide in the mammalian brain and the natural ligand for the NK(1) tachykinin receptor, plays an integrative role in the regulation of cardiovascular, neuroendocrine and behavioural responses to stress. In rats, stimulation of periventricular NK(1) receptors in the forebrain induces a distinct pattern of cardiovascular responses which is accompanied by intense grooming behaviour. Ligands for NK(3) receptors induce a different pattern of cardiovascular and behavioural responses which comprises an increased release of vasopressin from the posterior pituitary and wet-dog shakes behaviour. To define the brain areas in the rat which respond to stimulation of forebrain NK(1) and NK(3) receptors and participate in the generation of these responses, the induction of c-Fos immunoreactivity was examined in brains following intracerebroventricular injections of substance P and neurokinin B in conscious rats. Stimulation of central NK(1) receptors by substance P (25, 100 and 500 pmol) injected into the lateral ventricle elicited grooming behaviour (face washing and hind limb grooming) and resulted in a marked c-Fos expression in the paraventricular, dorsomedial and parabrachial nuclei and in the medial thalamus. At 25 pmol, substance P did not significantly increase c-Fos expression, at 100 pmol, maximal c-Fos activation was induced in all four brain regions which responded to the peptide. Intracerebroventricular pretreatment of rats with the selective and high-affinity, non-peptide NK(1) receptor antagonist, RP 67580 (500 pmol), but not with its inactive enantiomer, RP 68651, completely abolished the behavioural response to substance P and reduced the substance P-induced c-Fos expression in all brain areas to nearly control levels. Intracerebroventricular injection of the natural ligand for NK(3) receptors, neurokinin B (500 pmol), elicited wet-dog shakes behaviour and activated c-Fos expression in localized regions of the forebrain including the organum vasculosum laminae terminalis, subfornical organ, median preoptic nucleus, paraventricular, supraoptic and anterior hypothalamic nuclei, medial thalamus and in the ventral tegmental area. These results demonstrate that the neurokinins, substance P and neurokinin B, induce specific and different patterns of c-Fos expression in distinct regions of the rat brain. Brain areas which selectively responded to substance P have been traditionally linked to the central regulation of cardiovascular and neuroendocrine reactions to stress or involved in the processing of nociceptive responses. On the other side, brain areas activated by neurokinin B are known to be involved in the central regulation of blood pressure, water and salt homeostasis or control of behaviour.

Tachykinin receptor inhibition and c-Fos expression in the rat brain following formalin-induced pain.

Recent pharmacological evidence has implicated substance P and neurokinin A, natural ligands for neurokinin-1 and neurokinin-2 receptors, respectively, as neurotransmitters in brain neuronal circuits activated upon noxious stimulation. The expression of the inducible transcription factor, c-Fos, was used to identify areas in the brain activated by a noxious stimulus (the subcutaneous injection of formalin), and to investigate the effects of intracerebroventricular administration of selective, nonpeptide antagonists for neurokinin-1 and neurokinin-2 tachykinin receptors on the neural activity in these areas and on the behavioural response to formalin-induced pain. Formalin (5%, 50 microl), injected subcutaneously through a chronically implanted catheter in the region of the lower hindlimb, increased c-Fos expression in a number of brain areas related to nociceptive transmission or the integration of stress responses. Grooming behaviour, licking and biting directed to the injected site, was the most frequent behavioural response. Intracerebroventricular pretreatment of rats with either RP 67580 (500 pmol), the active enantiomer of a neurokinin-1 receptor antagonist, or with SR 48968 (500 pmol), the active enantiomer of a neurokinin-2 receptor antagonist, reduced the formalin-induced c-Fos staining in the prefrontal cortex, dorsomedial and ventromedial nuclei of the hypothalamus, the locus coeruleus and the periaqueductal gray. The neurokinin-1, but not the neurokinin-2, receptor antagonist attenuated the formalin-induced activation of c-Fos in the paraventricular nucleus of the hypothalamus. Simultaneous intracerebroventricular pretreatment with both neurokinin-1 and neurokinin-2 receptor antagonists did not produce any additional inhibitory effect on the post-formalin c-Fos expression. None of the tachykinin receptor antagonists had an effect on the formalin-induced c-Fos expression in the septohypothalamic nucleus, medial thalamus, parabrachial nucleus and central amygdaloid nucleus, indicating that neurotransmitters other than neurokinins are most probably responsible for the activation of these areas in response to noxious stimulation. While both tachykinin receptor antagonists reduced the grooming behaviour to formalin, the neurokinin-1 receptor antagonist was clearly more effective than the neurokinin-2 receptor antagonist. Intracerebroventricular pretreatment of rats with the inactive enantiomers of the tachykinin receptor antagonists, RP 68651 and SR 48965, was without effect. Our results show that (i) the modified formalin test elicited an intense grooming behaviour and expression of c-Fos in numerous forebrain and brainstem areas, (ii) both tachykinin receptor antagonists were able to attenuate the behavioural response to pain and to reduce the formalin-induced c-Fos expression in some, but not all, brain areas, and (iii) the neurokinin-1 antagonist, RP 67580, was more effective in inhibiting the behavioural response to formalin and the pain-induced activation of c-Fos than the antagonist for neurokinin-2 receptors, SR 48968, indicating that neurokinin-1 receptors are preferentially activated in neurokinin-containing pathways responding to noxious stimuli. Our results demonstrate that blockade of brain tachykinin receptors, especially of the neurokinin-1 receptor, reduces the behavioural response to pain and the pain-induced c-Fos activation in distinct brain areas which are intimately linked with nociceptive neurotransmission and the initiation and integration of central stress responses. Together with the previous findings of the inhibition of hypertensive and tachycardic responses to pain, the present data indicate that tachykinin receptor antagonists can effectively inhibit the generation of an integrated cardiovascular and behavioural response pattern to noxious stimuli.