Pulmonary Hypertension in Dialysis Patients: A Cross-Sectional Italian Study

Introduction. Pulmonary hypertension (PHT) is an independent predictor of mortality. The aim of this study was to relate pulmonary arterial pressure (PAP) to the cardiovascular status of dialysis patients. Methods. 27 peritoneal dialysis (PD) and 29 haemodialysis (HD) patients (60 ± 13 years, 37 males, dialysis vintage was 40 ± 48 months) had PAP measured by echocardiography. Clinical and laboratory data of the patients were recorded. Results. PHT (PAP > 35 mmHg) was detected in 22 patients (39%; PAP 42 ± 6 mmHg) and was diagnosed in 18.5% of PD patients and 58.6% of HD patients (P = .0021). The group of subjects with PH had higher dialysis vintage (63 ± 60 versus 27 ± 32 months, P = .016), interdialytic weight gain (2.1 ± 1 versus 1.3 ± 0.9 Kg, P = .016), lower diastolic blood pressure (73 ± 12 versus 80 ± 8 mmHg, P = .01) and ejection fraction (54 ± 13 versus 60 ± 7%, P = .021) than the patients with normal PAP. PAP was correlated positively with diastolic left ventricular volume (r = 0.32, P = .013) and negatively with ejection fraction (r = −0.54, P < .0001). PHT was independently associated with dialysis vintage (OR 1.022, 95% CI 1.002–1.041, P = .029) and diastolic blood pressure (OR 0.861, 95% CI 0.766–0.967, P = .011). Conclusions. PHT is frequent in dialysis patients, it appears to be a late complication of HD treatment, mainly related to cardiac performance and cardiovascular disease history

Time-dependent structure and control of arterial blood pressure - Closing remarks

Arterial blood pressure is under a complex neuro-endocrine regulation. The homeostatic vision of such regulation is largely incomplete and needs to be revised according to its temporal structure. The contributions reported here shed new light in this respect

Perspectives on the chronotherapy of hypertension based on the results of the MAPEC study

Appreciation of chronotherapy in hypertension continues to lag, despite clear demonstrations by many studies of (i) clinically relevant dosing-time differences of the beneficial and adverse effects of most blood pressure (BP) medications and (ii) significant association between reduced sleep-time BP decline of non-dippers and their heightened risk of cardiovascular disease (CVD). The Syst-Eur and HOPE outcome trials showed evening administration of nitrendipine and ramipril in these respective studies impacts sleep-time BP, converting the 24-h BP pattern to a more dipper one and in the HOPE study decreasing CVD risk. The CONVINCE study intended to compare BP control and CVD protection afforded by conventional β-blocker and diuretic medications versus a special drug-delivery verapamil formulation as a bedtime hypertension chronotherapy; however, the trial was terminated prematurely, not based on inadequate performance of the chronotherapy but on a corporate business decision. The just completed MAPEC study is the first trial specifically designed to prospectively test the hypothesis that bedtime administration of ≥1 conventional medications exerts better BP control and CVD risk reduction than the traditional approach of scheduling all medications in the morning. The results of this 5.6-yr median follow-up study establish that bedtime chronotherapy more effectively improves BP control, better decreases prevalence of non-dipping, and, most importantly, best reduces CVD morbidity and mortality. This chronotherapeutic approach to hypertension is justified by the fact that BP is usually lowest at night as is sodium excretion, but when sodium intake is excessive or its daytime excretion hampered, nocturnal BP is adjusted higher, to a level required for compensation overnight, via the pressure/natriuresis mechanism, resulting in non-dipping 24-h BP patterning. In diurnally active persons, the entire circadian BP pattern may be reset to a lower mean level and to a "more normal" day-night variation, simply by enhancing natriuresis during the night-the time-of-day when it can be most effective. A modification as simple and inexpensive as switching ≥1 hypertension medications from morning to evening may be all that is needed to normalize nighttime BP, exerting an effect exactly like sodium restriction. Current clinical concepts such as "normotensive non-dipper" (with higher CVD risk than a hypertensive dipper), broad recommendation of pharmacotherapy with exclusively high "smoothness index" medications (without attention to individual patient needs defined by the features of the 24-h BP pattern), and reliance upon static daytime diagnostic BP thresholds based solely on single office cuff assessment necessitate urgent reconsideration

From a static to a dynamic concept of risk: the circadian epidemiology of cardiovascular events

A growing body of evidence substantiates that the occurrence of cardiovascular events in unevenly distributed in time, especially during the 24 h. These temporal patterns are indicative of temporal variation in the (1) pathophysiological mechanisms that trigger cardiovascular events and (2) physiological status of the cardiovascular system, which combine to give rise to 24 h and other periodicities in the susceptibility to disease. The classic assumption of epidemiologic studies is constancy (or homeostasis) in one's risk to disease during the 24 h, as well as other, time domains. However, we propose a new concept, that of chronorisk since it takes into account the temporal variability in the pathophysiological mechanisms and their reciprocal temporal interactions that lead to day-night and other time-dependent patterns in cardiovascular events. This chronobiological approach, which is expected to contribute new insight into the prognostic and therapeutic assessment of cardiovascular events, is worthy of broader application in cardiovascular and other fields of medicine and warrants further investigation

The fast Fourier transform in the analysis of the normal phonocardiogram.

The present study is focused on spectrum analysis as a useful method of processing the PCG in order to obtain the frequency spectral distribution of normal heart sounds. Thirty normal subjects aged from 17 to 34 were studied. PCG was recorded on the fourth intercostal space at the left sternal border using a sound level meter coupled with a standard 6 ml cavity. The microphone had a linear response from 0.2 to 8,000 Hz. The signal was filtered with the standard B network according to the ANSI specifications and was registered on a four track FM tape recorder. A four channel analyzer with a microprocessor for off-line elaborations was used with 10 KHz sampling frequency. The PCG signal was triggered by a QRS detector on the R wave of the simultaneously recorded ECG. Fast Fourier transform was performed employing either a four channel analyzer with a microprocessor, or an A/D converter with a computer. Finally the results of the analysis were statistically elaborated. The described procedures permit to obtain a direct and exact tracing of the acoustic features of the heart, thus representing an attempt to come closer to the standardization and automatic analysis of the phonocardiographic technique

Seasonal variation in the occurrence of epistaxis

Several diseases have well-defined circadian or seasonal patterns. For example, in the United States, about 50% more acute myocardial infarctions occur during the winter than during the summer, whereas no seasonal variation is found in warmer regions. We conducted a prospective study in 1366 consecutive patients with epistaxis (mean [±SD] age 53 ± 22 years) who were seen in the emergency department of the St. Anna Hospital, in Ferrara, Italy, from January 1, 1992, to December 31, 1998. The total number of patients admitted each month, as well as the number of men, women, normotensive patients, and hypertensive patients were recorded, and rhythms analysis was performed by partial Fourier series. A significant annual rhythm, usually with a peak in January, was found in the total group of patients and in each subgroup (P<0.001 for all comparisons). There is no certain explanation for our findings. Dry air due to room heating could damage the prominent, thin-walled blood vessels responsible for epistaxis. In addition, the greater prevalence of upper respiratory infections during the winter is also likely to contribute to direct damage of the nasal mucosa

Le syndrome polygraphique du flutter auriculaire

Descrizione della sindrome poligrafica del flutter atrial

Oxidative stress in essential hypertension

A major cause for endothelial dysfunction in essential hypertension is decreased availability of nitric oxide (NO). Impairment in NO bioavailability is likely to be the consequence of multiple mechanisms affecting NO synthesis as well as NO breakdown. An alteration in the redox balance in endothelial cells leads to increased superoxide anion production and oxidative stress. This in turn not only exerts negative effects on vascular tone, but is also able to activate important mechanisms (such as platelet activity, leukocyte adhesion, vascular smooth muscle cell proliferation and expression of adhesion molecules) with an established central role in the pathogenesis of hypertensive target organ damage. As a consequence, a drug therapy able to restore NO availability in essential hypertensive patients would probably exert additional benefits, as compared to blood pressure lowering per se, in terms of prevention of target organ damage and improved prognosis of these patients. Unfortunately, as of today only the antagonists of the renin-angiotensin system and the calcium-channel blockers have shown some ability in this respect, whereas no longitudinal intervention study has been undertaken, so far, to prove that the restoration of NO bioavailability through an antihypertensive treatment may confer additional prognostic advantage to essential hypertensive patients

Ambulatory blood pressure monitoring: killing the elephant to get its hair? No more, please!

The hemodynamic burden imposed on the arterial walls by BP varies significantly from daytime (awake) to nocturnal (asleep) levels, but to a different extent in individual patients. There is no other practical way to estimate the total pro-atherogenic impact of BP in a given individual than to perform ambulatory blood pressure monitoring (ABPM) throughout the entire day and night. Medicine is full of similar situations, so that nobody would seriously assess melatonin or growth hormone function —just to make a couple of examples— by measuring only their daytime plasma levels. Believe it or not, most of the current international guidelines, including the European and the American ones, still do not recommend the routine use of ABPM in clinical practice, which makes routine users appear as some kind of poachers. At least one large, prospective, clinical trial has already demonstrated that an antihypertensive treatment guided by routine use of ABPM and aimed to preserve or restore the physiologic nocturnal fall of BP by selecting appropriate times of drug administration, is able to significantly reduce CV morbidity and mortality. Not only are the findings of that study a serious challenge to a number of current clinical concepts and therapeutic recommendations, but an increasing number of scientific evidence already available in the international literature strongly indicates that reliance upon static daytime diagnostic BP thresholds based solely on occasional office cuff assessment clearly necessitates urgent reconsideration. It is like being poachers killing elephants to get their hair while discarding all the rest, ivory tusks included! We need to stop this unwise attitude and start taking advantage of all ABPM-derived information to further improve the clinical management of arterial hypertension