Branko K. Lovic

The pathophysiological basis of carotid baroreceptor stimulation for the treatment of resistant hypertension.

The prevalence of resistant hypertension and existing limitations in antihypertensive drug therapy renders the interventional management of hypertension an attractive alternative. Carotid baroreceptors have been traditionally thought to be implicated only in short-term blood pressure regulation; however recent evidence suggests that the baroreceptors might play an important role even in the long-term blood pressure regulation. Electrical baroreflex stimulation appears safe and effective and might represent a useful adjunct to medical therapy in patients with resistant hypertension. This review endeavors to summarize the complex pathophysiology of blood pressure regulation, to describe the baroreflex circuit, its anatomy and physiology, to present previous data refuting a role for the baroreceptors in the long-term control of blood pressure and recent animal and human data suggesting an effective role of carotid baroreceptor activation in long-lasting blood pressure reduction. In this paper we attempt to critically evaluate existing information in this area and provide the scientific basis for carotid baroreceptor stimulation in the management of resistant hypertension.

THE AFFECT OF THE REGRESSION OF THE LEFT VENTRICULAR HYPERTROPHY OF THE FUNCTIONAL CAPACITY IN HYPERTENSIVE PATIENTS: PP.35.487

The objective of our study was to evaluate the effects of long-term antihypertensive treatment (after 8 years) in left ventricular hypertrophy (LVH), physical working capacity and arrhythmogenic marcers (QTc interval dispersion). Methods: 73 hypertensive patients were analyzed (44 male, aged 55.4 ± 8 years and 29 female aged 57.3 ± 6 years) who were an antihypertensive treatment with echocardiographic LVH (left ventricular mass index: 163 ± 30.3 g/m2). Each subject underwent two-dimensional and Doppler echocardiography, 12-lead electrocardiogram examination and exercise stress testing (Bruce - protocol). Results: Decrease of index LVM (I group – regression LVH) was achieved in 37 pts (51% - 172.2 vs 142.08 g/m2; p < 0.005), while in 36 pts it was increased (II group – progression LVH) (49% - 152.5 vs 158.7; ns). The reduction was due to a decrease in septal (13.4 vs 12.3; p < 0.05) and posterior wall thickness (11.4 vs 10.7 vs 1.2; p < 0.03), without changes in LV diameter. In patients of the I group ratio of the velocity time integrals of »E to »A mitral waves increase (E/A before Th 0.83 vs 0.92, p < 0.05). Patients with reduction of the left ventricular mass could be shown a significant reduction of QT dispersion from 64.9 ± 21.8 to 51.1 ± 15.9 ms (p < 0.009), opposite the patients with progression LVH (49.5 ± 14.5 vs 45 ± 12.5; ns). After regression LVH (I group), the functional capacity was increase (6.35 vs 7.56 METs; ns), decrease maximum systolic BP (205.7 vs 201.6 mmHg, ns), decrease peak double products (26.8 vs 26.2, ns), and significantly decrease double product/METs (2.6 vs 1.9, p < 0.05) in third minuts while it remained unchanged in pts of the II group. Conclusion: LVH regression in our patients was achieved by the decrease of wall thickness of the left ventricle and it is followed by the improvement of the functional capacity and by the reduction of QT dispersion.

PREDICTIVE VALUE OF NON-INVASIVE PARAMETERS DURING EIGHT YEARS FOLLOW-UP OF PATIENTS WITH HYPERTENSIVE LEFT VENTRICULAR HYPERTROPHY: PP.22.378

Objective: The aim of the study was to examine the correlation between non-invasive parameters and outcomes in patients (pts) with essential arterial hypertension (AH) and left ventricular hypertrophy (LVH) during eight years follow-up. Design and Method: Ninety pts were examined (55.2 ± 8.3 years; 56 male and 34 female) with AH and LVH. All pts were examined by means of echocardiography, exercise testing, 24-h Holter monitoring, 24-h ambulatory blood pressure monitoring, heart rate variability, ventricular late potentials, spectral turbulence analysis and QTc interval dispersion. Results: Average left ventricular mass index (LVMI) was 171.9 ± 32.4 g/m2 and duration of hypertension was 12.3 ± 7.9 years. During eight years follow-up in 22 (24.4%) pts occurred cardiovascular and cerebrovascular adverse events (AE). At the beginning of the study pts with AE had greater: LVMI (184.1 ± 36.3 g/m2 vs. 168.4 ± 30.3 g/m2; p < 0.05), septum thickness (p < 0.05), posterior wall thickness (p < 0.05) and relative wall thickness (p < 0.05). In pts with AE QTc dispersion was greater than in pts without AE (69.3 ± 20.2 ms vs. 56.4 ± 20.6 ms; p < 0.02). These pts had frequent premature ventricular beat per hours (p < 0.05) in 24-hours holter monitoring. The QTc dispersion greater than 60 ms was found in 17 (77.3%) pts with AE and in 30 (44.1%) pts without AE (p < 0.01). Using multiple linear regression analysis the best predictor of worse prognosis were greater QTc dispersion and posterior wall thickness (standardized coefficient beta: for QTc dispersion 0.254; p < 0.02 and for posterior wall thickness 0.207; p < 0.05 and for model: R = 0.331, R2 = 0.110, adjusted R2 = 0.089, standard error of the estimate = 0.416). Conclusions: Patients with greater QTc dispersion, especially greater than 60 ms, and greater posterior wall thickness have worse outcome during eight years in spite of regular medical treatment.

EFFECTS OF THE EARLY ONE YEAR TREATMENT IN HYPERTENSIVE LEFT VENTRICULAR HYPERTROPHY AND SIGNIFICANCE ON CARDIOVASCULAR EVENTS IN THE FUTURE: PP.22.373

Left ventricular hypertrophy (LVH) is a powerful predictor of cardiovascular morbidity and mortality. Ambulatory blood pressure monitoring (ABPM) has been proved to be superior to clinic blood pressure measurement for cardiovascular risk stratification and LVH. Objective: The aim of the present follow-up study was to evaluate the prognostic significance of the early investigated parameters as well as the effects of the changed investigated parameters after 12 month treatment on the long term prognosis of the patients with hypertensive LVH. Patients and Methods: A total of 73 age matched, no diabetic, hypertensive male (n = 44, aged 55.4 ± 8 years) and female (n = 29, aged 57.3 ± 6 years) patients with echocardiographically proved LVH, were analyzed for cardiovascular death, fatal or non-fatal myocardial infarction and stroke and revascularization procedures after 12 year follow-up. Each patient underwent: Doppler Echocardiography, Exercise stress testing, 24-hour ABPM, Holter monitoring and heart rate variability (standard deviation of all 24-hour NN intervals (SDNN, ms). Results: After 12 years of observation, 12 patients (16%) had serious cardiovascular incidents and 6 died (8%). Presence of metabolic syndrome at the beginning of the study influenced the appearance of significant cardiovascular events and death, one year earlier than in patients without MS. Multivariant analysis of investigated parameters after one year treatment showed that the death risk increases the missing of average daily diastolic BP (1.419; (95% CI for Exp(B)-1,049–1.918; p = 0.023), rising of the average night systolic BP (1.206; (95% CI for Exp(B)-1,039–1.399; p = 0.014) as well as rising of average night heart rate(1.306; (95% CI for Exp(B)-1,023–1.668; p = 0.032). Increasing of LVM index (1.014; 95% CI for Exp(B)-1,002–1.026; p = 0.026) and higher decrease of night diastolic BP (1.247; 95% CI for Exp(B)-1,083–1.437; p = 0.002). suggest the risk of both significant cardiovascular events and death. Conclusion: Increase of LVM index and poor 24 hour BP regulation are major predictors of future serious cardiovascular incidents in hypertensive patients with LVH.

METABOLIC SYNDROME AND ATHEROSCLEROSIS OF CAROTID ARTERIES IN HYPERTENSIVE PATIENTS WITH LEFT VENTRICULAR HYPERTROPHY: PP.2.79

Hypertension as a part of the metabolic syndrome (MS) is risk factors for some patients with cardiovascular diseases. Aims was to prove the presence of MS at patients with hypertension and left ventricular hypertrophy (LVH) analyzing clinical parameters, and to estimate the impact factor of MS on patient prognosis. Method: 82 hypertensive patients was analyzed (48 male), average age 55.38 ± 7.2 with echocardiographically proved LVH (average LVMI 164.23 ± 30.72 g/m2). Results: 39 patients (57 ± 7 years) fulfilled the criterion of MS. They had significantly higher glucose level, lower HDL cholesterol, higher triglycerides and higher body mass index (30.6 ± 4.6 vs. 26.5 ± 3,4, p < 0.03). This group of patients had more frequent complex VA and significantly lower values of HRV. After eleven years of observation, six patients in this group had fatal CV events (4 CVI – 4 deaths, 2 sudden death), while in the second group, three patients had three sudden deaths (ns). The purpose of this study was to investigate the subclinical carotid atherosclerosis prevalence in different groups, with and without metabolic syndrome. ColourDuplex ultrasonography of the carotid arteries was performed on Toshiba ultrasaund with linear probe of 7.5 MHz. The thickness of the intimomedial complex in patients with MS was 1.13 ± 0.05 vs. 0.92 ± 0.08 mm in patients without MS. Thertheen patients with MS (33%) had carotid plaques, and at 43% of patients had been diagnosed coronary disease (4 IM, 4 PTCA with inbuilt stent,5 with angina pectoris and positive exercise tests), while 20% of patients with non MS had carotid plaques (p < 0.04), and 9% had coronary disease (p < 0.002). Conclusions: Results of our study showed that patients with LVH and MS had significantly greater prevalence of the carotid atherosclerosis and CAD, and high correlation between carotid artery disease and presence and severity of CAD.

Value of Exercise Testing in Evaluating the Effects of Early Posthospital Rehabilitation in Patients after Myocardial Infarction

Physical training is the most important method in the rehabilitation program in patients after myocardial infarction. It should begin as soon as possible after the cardiovascular event, if the contraindications are not present (6). Physical training must be individually prescribed and supervised. In order to prescribe a regular physical training, it is necessary to determine the coronary reserve in each patient, which is possible by using exercise testing as a noninvasive method. This can be performed without risks in the selected group of patients after myocardial infarction.