The hemodynamic patterns in hypertensive men and women of different age.

Aging is associated with cardiovascular remodeling, which can be accelerated in arterial hypertension (AH). The aim of this study was to evaluate the relation between hemodynamic profile and age, as well as to identify the role of sex in hemodynamic patterns of aging in AH. The study comprised 326 patients with AH (mean age: 44.3 years). Two-dimensional echocardiography was performed to evaluate, that is, left ventricular diastolic dysfunction (LVDD) and ejection fraction (LVEF), and ICG to evaluate, that is, acceleration time index (ACI), velocity index (VI), total arterial compliance (TAC), systemic vascular resistance index (SVRI) and thoracic fluid content (TFC). The statistical analysis included interquartile comparison in subgroups of age <19-37 years (Q1), 38-44 years (Q2), 45-51 years (Q3) and 52-68 years (Q4). Aging was associated with: (1) higher prevalence of LVDD (Q1 vs Q4: 11.0% vs 24.7%, P=0.023); (2) altered LV systolic performance-ACI (81.4 vs 64.0 1/100 Ω s(-2), P=0.0001), VI (50.5 vs 42.8 1/1000 Ω s(-1), P=0.006), LVEF (65.4% vs 67.0%, NS); and (3) increased afterload-TAC (2.25 vs 1.87 ml mm Hg(-1), P=0.0001), SVRI (2182 vs 2407 dyn s m(2) cm(-)(5); P=0.045). The 'U-shaped' relation to age was observed for TFC. The above-mentioned hemodynamic trends were more pronounced in men, whereas females presented the 'middle-aged delay'. The influence of aging on cardiovascular system shows in progressive arterial stiffness and impaired left ventricular function. Thoracic fluid reduction may be compensatory to vasoconstriction but its efficiency declines with age. The patterns of cardiovascular aging are different in men and women.

Sex determines cardiovascular hemodynamics in hypertension.

The aim of this study was to evaluate the influence of sex on cardiovascular hemodynamics and heart remodeling in 144 patients with arterial hypertension that underwent: (1) echocardiography (that is, indices of left ventricular diastolic function: e', E/e'), (2) impedance cardiography (that is, systemic vascular resistance (SVR), total artery compliance (TAC) and Heather index (HI)) and (3) applanation tonometry (augmentation index (AI), central systolic and diastolic blood pressure (CSBP, CDBP), central pulse pressure (CPP)). Women, in comparison with men, revealed to have: (1) stiffer arteries--lower TAC (1.93±0.55 vs 2.16±0.59 ml per mm Hg; P=0.025), higher CSBP (128.7±14.9 vs 123.4±13.2 mm Hg; P=0.036), CPP (39.9±9.5 vs 33.8±9.0 mm Hg; P=0.0002), AI (31.5±8.7 vs 17.5±12.7%; P<0.00001), SVR (1257.6±305.6 vs 1091.2±240.7 dyn × s × cm(-)(5); P=0.002) and (2) higher left ventricular performance--HI (16.3±4.3 vs 11.7±3.2 Ohm × s(2); P<0.00001). In women CSBP, CPP and AI were more clearly associated with left ventricular filling pressure (e') (r=-0.39, r=-0.45, r=-0.44, P<0.01; respectively). These relations were remarkably weaker in men. Hypertensive women characterized with lower large artery compliance, more pronounced augmentation of central blood pressure and more distinctive association of central blood pressure with left ventricular diastolic function. Sex differences in cardiovascular function can impact the individualized management of arterial hypertension.

Left ventricular diastolic dysfunction is associated with impaired baroreflex at rest and during orthostatic stress in hypertensive patients with left ventricular hypertrophy.

The study aimed to determine the relationship between left ventricular (LV) diastolic function and the heart's spontaneous baroreflex at rest and in response to orthostatic stress during a prospective follow-up of hypertensive patients with LV hypertrophy (LVH+). LV structure and function and baroreflex sensitivity (BRS) during tilt testing were evaluated in 24 LVH+ patients and compared with 25 age-matched healthy controls and 25 hypertensive patients without LVH (LVH-). Clinical status, diastolic function and BRS were then assessed in LVH+ patients during treatment with telmisartan (monotherapy or combined with hydrochlorothiazide and/or amlodipine) at 6- and 18-month follow-ups. LVH+ patients had significantly altered diastolic function indices and decreased BRS as compared with healthy controls and LVH- patients. During the 18-month follow-up, favorable changes in diastolic function were associated with improvement in BRS at rest and during tilting. In multivariate regression models, an index reflecting rate of LV myocardial relaxation (E'sept) where E'sept denotes peak early diastolic velocity at the septal mitral annulus and a surrogate for LV filling pressure (E/E'sept), independently from other clinical and echocardiographic variables related to the low-frequency component of BRS during tilting. In conclusion, the LV diastolic function indices have independent associations with BRS parameters obtained at rest and during orthostatic stress in LVH+ patients receiving long-term pharmacological intervention.

Nonlinear oscillator model reproducing various phenomena in the dynamics of the conduction system of the heart.

A dedicated nonlinear oscillator model able to reproduce the pulse shape, refractory time, and phase sensitivity of the action potential of a natural pacemaker of the heart is developed. The phase space of the oscillator contains a stable node, a hyperbolic saddle, and an unstable focus. The model reproduces several phenomena well known in cardiology, such as certain properties of the sinus rhythm and heart block. In particular, the model reproduces the decrease of heart rate variability with an increase in sympathetic activity. A sinus pause occurs in the model due to a single, well-timed, external pulse just as it occurs in the heart, for example due to a single supraventricular ectopy. Several ways by which the oscillations cease in the system are obtained (models of the asystole). The model simulates properly the way vagal activity modulates the heart rate and reproduces the vagal paradox. Two such oscillators, coupled unidirectionally and asymmetrically, allow us to reproduce the properties of heart rate variability obtained from patients with different kinds of heart block including sino-atrial blocks of different degree and a complete AV block (third degree). Finally, we demonstrate the possibility of introducing into the model a spatial dimension that creates exciting possibilities of simulating in the future the SA the AV nodes and the atrium including their true anatomical structure.

[Permanent heart pacing in treatment of cardioinhibitory vasovagal syncope (case report)]. / Stala stymulacja serca w leczeniu postaci kardiodepresyjnej zespolu wazowagalnego (opis przypadku).

Vasovagal syncope is a complex syndrome in which specific methods of treatment rarely are related to clinical success. Since it turned out that some patients with neurocardiogenic syncope were resistant to offered pharmacotherapy, cardiac pacing has been used as the alternative way of long-term therapy. Successive studies, which have estimated clinical efficacy of permanent cardiac pacing, indicate that such method of treatment may reduce symptoms revealed by vasovagal reflex. Nevertheless the optimal pacing mode has not been established yet. It is known that single chamber VVI pacing is not a good and effective method whereas dual chamber DDI pacing with rate hysteresis seems to be very promising in treatment of people suffering from malignant cardioinhibitory vasovagal syncope. DDD pacing with rate drop response, search and scan functions recently has been available to these patients. The results of the North American Vasovagal Pacemaker Study, as well as some casuistic observations referring to patients with vasovagal syndrome, show very high clinical efficacy of dual chamber pacing with mentioned new functions. We present a case of patient with cardioinhibitory vasovagal syncope who was successfully treated by permanent DDD pacing with search and scan hysteresis.

[The prolonged asystole during head down tilt test: prognostic significance and therapy]. / Przedluzona asystolia podczas testu pochyleniowego--znacznie prognostyczne i leczenie.

The head up tilt test is a worthy of acknowledgment and widely accepted tool used in diagnosing patients with syncope of unknown origin. In some cases tilting provokes asystole lasting even several tens of seconds. Not long ago this kind of vasovagal reaction was being associated with appearance of syncope combined with body injures. The prognostic significance of asystole during head-up tilt test and the safe and efficacious way of therapy in such cases hasn't been established yet. There were three cases of vasovagal reaction, resulting in asystole, described in order to show a large number of diagnostic and therapeutic problems related to the discussed syndrome. The presentation of actual views on diagnosing and therapy of patients with vasovagal syndrome, as a matter of fact is a synthesis of published results of clinical studies and its aim is to be more objective about so many obliging theories.

[Marfan's syndrome: diagnosis and treatment]. / Zespól marfana--diagnostyka i leczenie.

The Marfan syndrome is an autosomal dominant inherited disorder of connective tissue with pleiotropic manifestation involving mainly the cardiovascular, ocular, skeletal and pulmonary systems. Aortic root dilatation and heart valve lesions are particularly common and presage a reduced life expectancy. Over the ensuring 20 years, however, treatment to prevent or correct the cardiovascular complications of the syndrome has changed dramatically--life expectancy for patients with the Marfan syndrome has increased > 25%. Reasons for this dramatic increase may include (1) an overall improvement in population life expectancy, (2) benefits arising from cardiovascular surgery, and (3) greater proportion of milder cases due to increased frequency of diagnosis. Cardiovascular surgery, both prophylactic and emergent, has become accepted treatment for aortic aneurysm, and aortic dissection. In addition, beta-adrenergic receptor antagonists have gained wide acceptance as potential agents for delaying aortic expansion and progression to rupture or dissection. In conclusion, medical therapy is also associated with an increase in probable survival.