Özen Güven

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.

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.

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.

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.

Comparison of pre- and postoperative pulmonary function in obese and non-obese female patients undergoing coronary artery bypass graft surgery

Objective and background:  Various studies have suggested that body size and in‐hospital mortality are related. However, only a few analysed the effects of obesity on pulmonary complications following coronary artery bypass graft surgery (CABG). The purpose of the present study was to assess early changes in lung volumes, respiratory complications and arterial blood gas tension following CABG in obese women.

The efficacy of valsartan in essential hypertension and its effects on left ventricular hypertrophy.

Recent studies demonstrate that, treatment with angiotensin-converting enzyme (ACE) inhibitors and angiotensin-II receptor blockers may decrease left ventricular hypertrophy (LVH) in hypertensive patients. We wanted to assess the efficacy of valsartan on echocardiographic variables of LVH in 30 mild to moderate hypertensive patients. Valsartan was found effective in controlling hypertension, also echocardiographic indices of LVH such as interventricular septum and posterior wall thickness were reduced and left ventricular mass decreased significantly. Thus valsartan favorably influences cardiac structure in hypertensive patients.