Drugs with blocking effects on the renin-angiotensin-aldosterone system do not improve endothelial dysfunction long-term in hypertensive patients.

In essential hypertension, endothelial dysfunction has been documented many times and correlates with prognosis. The influence of the renin-angiotensin-aldosterone system (RAAS) on endothelial dysfunction has also been studied. The present study investigated the duration of the effects of RAAS-blocking drugs on endothelial function in 44 consecutive, never-treated, outpatients with mild to moderate hypertension. Patients (11 per group) received an angiotensin receptor blocker (ARB; irbesartan 300 mg/day or valsartan 160 mg/day) or an angiotensin-converting enzyme inhibitor (ACEi; fosinopril 10 mg/day or quinapril 20 mg/day). If target blood pressure (< 140/90 mmHg) was not achieved, 12.5 mg/day hydrochlorothiazide was added. Endothelial function, assessed by measuring brachial artery diameter, did not change significantly after 6 weeks, 1 year or 3 years of treatment in any group. Across all groups, endothelium-dependent and -independent vasodilation increased significantly after 6 weeks but, after 1 year, decreased below baseline and was at a similar level after 3 years; groups did not differ significantly. Both ACEi and ARB had similar effects on endothelial function; improvement occurred at the start of treatment but was not maintained. Endothelial dysfunction may be a resistant or irreversible feature of hypertension, requiring high doses of antihypertensive drugs and above-average patient compliance.

Heart rate variability in diabetes patients.

Diabetes mellitus can cause cardiovascular autonomic neuropathy and is associated with increased cardiovascular deaths. We investigated cardiovascular autonomic neuropathy in diabetics and healthy controls by analysis of heart rate variability. Thirty-one diabetics and 30 age- and sex-matched controls were included. In the time domain we measured the mean R - R interval (NN), the standard deviation of the R - R interval index (SDNN), the standard deviation of the 5-min R - R interval mean (SDANN), the root mean square of successive R - R interval differences (RMSSD) and the percentage of beats with a consecutive R - R interval difference > 50 ms (pNN50). In the frequency domain we measured high-frequency power (HF), low-frequency power (LF) and the LF/HF ratio. Diabetes patients had lower values for time-domain and frequency-domain parameters than controls. Most heart rate variability parameters were lower in diabetes patients with chronic complications than in those without chronic complications.

The role of HLA molecules in susceptibility to chronic rheumatic heart disease.

Only a small fraction of the streptococcal pharyngitis progress to rheumatic carditis, which implies that environmental, host and microbial factors interact to cause an aberrant immune response against the antigens of the microorganism that cross-react with cardiac tissues. Although there are numerous studies and a general consensus on the relation between human leucocyte antigen (HLA) class II antigens and rheumatic heart disease (RHD), the details and the culprit antigens are still controversial. The study was undertaken to examine 100 patients with chronic RHD and 100 controls for HLA class I and class II antigens for differences in prevalence. All samples were typed at the HLA-DRB1/3/4/5 and DQB1 loci by the sequence-specific primer (PCR-SSP) method at low resolution. For HLA class I antigens, HLA-B13 frequency was marginally increased in patients with RHD compared to controls without reaching statistical significance. For class II antigens, RHD patients had higher frequencies for HLA-DRB1*01 (RHD 24%, controls 10%), DRB1*04 (RHD 35%, controls 26%), DRB1*07 (RHD 18%, controls 11%) and HLA-DQB1*02 (RHD 32%, controls 17%) without reaching statistical significance, and significantly lower frequencies for DRB1*13 (Pc < 0.003, OR: 5.69), DRB5* (Pc < 0.003, OR: 33) and DRB3* (Pc = 0.03, OR: 2.66) compared to controls. It was concluded that host, microbial and environmental factors collude to create acute rheumatic fever (RF) and chronic rheumatic valve disease. The HLA-DRB1*13, DRB5* and DRB3* were protective against the development of rheumatic valve damage.

Echocardiographic findings in professional league soccer players. Effect of the position of the players on the echocardiographic parameters.

BACKGROUND: The purpose of the study was to compare the echocardiographic parameters of soccer players to healthy controls and to assess the effect of the position of the soccer players on the echocardiographic findings. METHODS: M Mode 2D and Doppler echocardiographic examination were carried out on 83 professional league soccer players and 52 healthy controls. RESULTS: Soccer players had increased interventricular septum (1.14+/-0.13 cm vs 0.99+/-0.17 cm, p<0.001) left ventricular posterior wall (1.08+/-0.16 cm vs 0.91+/-0.13 cm, p<0.001) thickness, increased left ventricular diastolic diameter (5.24+/-0.40 cm vs 4.88+/-0.43 cm, p<0.001), volume (133+/-23 ml vs 113+/-22 ml, p<0.001) and increased left ventricular mass index (142+/-28 g/m2 vs 103+/-23 g/m2, p<0.001) compared to controls. Soccer players had greater mitral E wave to A wave ratio (2.08+/-0.53 vs 1.65+/-0.43, p<0.001) compared to controls. Soccer players were subgrouped according to their position in the play as goal keepers, defensive, midfielder, and offensive players. Comparison among defensive, midfield and offensive players revealed subtle differences between defensive and midfield players. Right ventricular dimensions were higher in goal keepers compared to midfielders due to the greater body surface area of the goal keepers (2.8+/-0.4 cm vs 2.4+/-0.5 cm, p<0.05). Left ventricle end diastolic dimension were similar between groups but when these dimensions were corrected for the greater height of the defensive players the difference between midfields and defensive players became significant (3.05+/-0.18 vs 2.89+/-0.22, p=0.05). On Doppler flow parameters the ratio of peak E wave to A wave velocity (2.27+/-0.55 vs 1.84+/-0.36, p<0.05) was increased in midfield players compared to defensive players. CONCLUSIONS: It was concluded that soccer players had greater left ventricular wall thickness, volume and mass compared to controls. But the effect of the position of the players on the measured cardiac dimensions were minimal. These subtle findings were explained by the leveling effect of the playing system and training, and lack of physical training during the previous month.

Effect of Valsalva maneuver on surface electrocardiographic P-wave dispersion in paroxysmal atrial fibrillation.

The purpose of this study was to investigate the effect of the Valsalva maneuver on P-wave durations and dispersion. After the Valsalva maneuver, we found that maximum P-wave duration increased, minimum P-wave duration decreased, and P-wave dispersion increased in controls, whereas the opposite was true for unselected patients with paroxysmal AF. It was concluded that patients with paroxysmal AF performing the Valsalva maneuver normalized their P-wave dispersion, thereby correcting the inhomogeneous intra-atrial conduction.

Autonomic dysfunction in vitamin B12 deficiency: a heart rate variability study.

This study was arranged to examine whether vitamin B12 deficiency may cause autonomic dysfunction. Time-domain and long-term frequency-domain heart rate variability parameters from 12 patients with pernicious anemia were compared to 12 age and sex matched controls. In B12 deficient patient group time-domain parameters; SDNN (100.4 +/- 37.86 vs. 131.91 +/- 26.94, P = 0.05), SDANN (87.00 +/- 37.77 vs. 118.83 +/- 26.22, P = 0.05) SD (39.41 +/- 13.32 vs. 53.41 +/- 15.39, P = 0.0221), rMSSD (21.41 +/- 10.00 vs. 28.5 +/- 8.42, P = 0.046) were significantly lower when compared to controls. Difference in pNN50 between groups were not statistically significant. In B12 deficient patients frequency-domain parameters; total power (23.08 +/- 9.89 vs. 34.75 +/- 9.56, P = 0.0078), low frequency power (13.5 +/- 6.57 vs. 22.75 +/- 7.25, P = 0.0069) and high frequency power (7.58 +/- 4.25 vs. 11.58 +/- 3.80, P = 0.0175) were significantly lower when compared to controls. It was concluded that B12 deficiency may cause autonomic dysfunction.