Effect of losartan on the blood-brain barrier permeability in diabetic hypertensive rats.

Our previous publication has stressed the benefits of losartan, an angiotensin II receptor blocker, on the permeability of blood-brain barrier (BBB) and blood pressure during L-NAME-induced hypertension. This study reports the impacts of anti-hypertensive treatment by losartan on the brain endothelial barrier function and the arterial blood pressure, during acute hypertension episode, in experimentally diabetic hypertensive rats. Systolic blood pressure measurements were taken with tail cuff method before and during administration of L-NAME (0.5 mg/ml). We induced diabetes by using alloxan (50 mg/kg, i.p). Losartan (3 mg/kg, i.v) was given to rats following the L-NAME treatment. Acute hypertensive vascular injury was induced by epinephrine (40 microg/kg). The BBB disruption was quantified according to the extravasation of the Evans blue (EB) dye. L-NAME induced a significant increase in arterial blood pressure on day 14 in normoglycemic and hyperglycemic rats (p < 0.05). Losartan significantly reduced the increased blood pressure in hypertensive and diabetic hypertensive rats (p < 0.01). Epinephrine-induced acute hypertension in diabetic hypertensive rats increased the content of EB dye dramatically in cerebellum and diencephalon (p < 0.01) and slightly in both cerebral cortex (p < 0.05). Losartan treatment reduced the increased BBB permeability to EB dye in the brain regions of diabetic hypertensive rats treated with epinephrine (p < 0.05). This study indicates that, in diabetic hypertensive rats, epinephrine administration leads to an increase in microvascular-EB-albumin efflux to brain, however losartan treatment significantly attenuates this protein's transport to brain tissue.

Increased QT dispersion in hemodialysis patients improve after renal transplantation: a prospective-controlled study.

Increased QT dispersion (QTd), predicting patients with risk of malignant arrhythmia, have recently been reported in hemodialysis patients (HDp). In this prospective study, we aimed to investigate changes in QTd and signal averaged-ECG (SAECG) in HDp after transplantation. Twenty-seven HDp (M/F:18/9, mean age 30+/-8 years) and 24 controls (M/F:14/10, mean age 33+/-6 years) were included. All QT parameters (QTmax, Qtmin, and QTd) were increased in HDp. QTmax and QTd started to decrease at the first month after transplantation. Percentage change in QTd at the third month was significantly correlated with percentage change in LV mass index (r=0.45, P=0.04), serum calcium (r=-0.47, P=0.02) and intact parathyroid hormone (r=0.68, P=0.01). In multivariate regression analysis, only percent chance in LV mass index was retained as significant. As for analysis of SAECG, 4 of the 23 (17%) HDp has abnormal late potentials which disappeared after transplantation. HDp with LV hypertrophy had higher filtered-QRS duration compared to patients without hypertrophy (110+/-12 vs. 97+/-11 msec, P=0.01). It was concluded that increased QTd and presence of late potentials improved early after renal transplantation. These changes were mainly associated with the regression of the LV mass.

Effect of left atrial size and function on P-wave dispersion: a study in patients with paroxysmal atrial fibrillation.

BACKGROUND: Paroxysmal atrial fibrillation (PAF), a common arrhythmia, is caused by the fractionated and nonhomogeneous propagation of sinus impulse. HYPOTHESIS: This study was undertaken to examine the effect of left atrial (LA) dimension and function on P-wave dispersion (deltaP) in unselected patients with PAF and health controls. METHOD: In this study, 62 consecutive patients with PAF (32 men, 30 women, mean age 55+/-11 years) and 62 age- and gender-matched healthy controls (33 men, 29 women, mean age 52+/-13 years) were studied to compare the effect of LA size, volume, and function on deltaP (difference between maximum and minimum P-wave duration on 12-lead electrocardiogram). RESULTS: P-wave dispersion in patients with PAF and normal LA diastolic diameter (LAD) was longer than that in controls with normal LA size (53+/-8 vs. 34+/-8 ms, p < 0.001). P-wave dispersion increased in patients with PAF (62+/-12 vs. 53+/-8 ms, p = 0.003) and controls (40+/-7 vs. 34+/-8 ms, p = 0.005) with increased LAD. Presence or absence of PAF did not interact with LAD for their effect on deltaP (2 x 2 analysis of variance test p = 0.20). In the PAF group, deltaP correlated with LAD (r = 0.43, p = 0.002), LA diastolic volume (r = 0.6, p < 0.001), and LA ejection fraction (AEF) (r = - 0.33, p = 0.05). The AEF was preserved when LAD increased in the patients without PAF (0.52+/-0.07 vs. 0.57+/-0.10, p = NS), however was significantly decreased in the PAF group (0.37+/-0.12 vs. 0.49+/-0.10, p = 0.01). On multivariate logistic regression analysis, only deltaP retained significance on development of PAF. CONCLUSION: It was concluded that deltaP increased in patients with PAF and normal LA size. In controls with increased LA size, deltaP increased but did not reach the levels attained in patients with PAF. The AEF was decreased in patients with PAF but was preserved in those without PAF. These findings can be explained by the changes in LA microarchitecture which concurrently decreased atrial myocardial contraction, increased deltaP, and predisposed to PAF.

QT dispersion and signal-averaged electrocardiogram in hemodialysis and CAPD patients.

OBJECTIVE: The aim of this study was to compare QT dispersion (QTd) and signal-averaged electrocardiogram (SA-ECG) parameters that may predict risk of malignant arrhythmias in patients on hemodialysis (HD), on continuous ambulatory peritoneal dialysis (CAPD), and in controls. SETTING: Controlled cross-sectional study in a tertiary-care setting. PATIENTS: 28 HD (M/F 18/10; mean age 32 +/- 9 years), 29 CAPD (M/F 17/12; mean age 34 +/- 10 years), and 29 healthy controls (M/F 17/12; mean age 32 +/- 8 years) were included. INTERVENTIONS: On ECG, minimum (QTmin) and maximum (QTmax) QT duration and their difference (QTd) were measured. In SA-ECG, duration of filtered QRS, HFLA signals less than 40 microV, and RMS voltage (40 ms) were also measured. RESULTS: Higher serum Ca2+ and lower K+ levels were found in CAPD compared to HD. All QT parameters were increased in HD and CAPD compared to controls. QT dispersion was significantly prolonged in HD compared to CAPD. In HD, QTd was correlated with left ventricular (LV) mass index (r = 0.53, p = 0.004), but not in CAPD (r = -0.09, p = 0.63). QT dispersion was significantly prolonged in patients with LV hypertrophy compared to patients without hypertrophy on HD (68 +/- 18 ms vs 49 +/- 18 ms, p = 0.008). In the analysis of SA-ECG, 3 of the 28 (11%) HD and 2 of the 29 (7%) CAPD patients had abnormal late potentials. Patients on HD and CAPD had significantly higher filtered-QRS duration compared to controls (105 +/- 15 ms and 104 +/- 12 ms vs 95 +/- 5 ms, respectively, p = 0.04). Patients with LV hypertrophy had higher filtered-QRS duration compared to patients without hypertrophy (109 +/- 12 ms vs 95 +/- 8 ms, p < 0.001). CONCLUSION: Dialysis patients had prolonged QTd and increased filtered-QRS duration in SA-ECG compared to controls. Patients on HD had longer QTd than patients on CAPD. QTd has been correlated to LV mass index in HD, but not in CAPD. This difference might be due to the effect of different dialysis modalities on electrolytes, especially the higher serum Ca2+ levels.

Assessment of left atrial appendage function and its relationship to pulmonary venous flow pattern by transesophageal echocardiography.

We evaluated left atrial appendage function and its relationship to pulmonary venous flow in 53 patients divided into four groups. Group 1 consisted of 10 normal subjects. Group 2 included 15 patients with significant pure mitral stenosis in sinus rhythm. In group 3, there were 13 patients with pure significant mitral stenosis and atrial fibrillation. Group 4 consisted of 15 patients with normal mitral valve and atrial fibrilltion. We found significant decrease in left atrial appendage ejection fraction and maximum emptying flow velocity, velocity time integral of systolic pulmonary venous flow in Groups 2, 3 and 4 in comparison with normal subjects. Systolic pulmonary venous flow velocity was significantly decreased in Groups 3 and 4. There was significant correlation between left atrial appendage ejection fraction and peak emptying flow velocity (r = 0.62, P < 0,001). Systolic peak pulmonary venous flow velocity was significantly correlated with left atrial appendage ejection fraction and maximum emptying flow velocity (r = 0.67, P = 0,01; r = 0.58, P < 0,001, respectively). There was also significant correlation between systolic pulmonary venous flow velocity time integral and left atrial appendage ejection fraction (r = 0.66, P = 0.001). When normals were excluded from analysis, all the correlations were still significant. We concluded that left atrial appendage is a contractile structure, and that systolic pulmonary venous flow velocity is influenced by left atrial appendage dysfunction. Therefore left atrial appendage function needs to be considered when interpreting Doppler transmitral and systolic pulmonary venous flow patterns.

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.

Left ventricular hydatid cyst: an unusual location of Echinococcus granulosus with multiple organ involvement.

Cardiac Echinococcus is rare but usually associated with fatal complications. An unusual case of cardiac hydatid cyst with multiple organ involvement is presented in which transesophageal echocardiography provided additional information and confirmed transthoracic echocardiographic findings.

Family practice in Turkey.

Family practice is a very new medical specialty in Turkey. Family practice residency programmes have been attended since 1985 only in state hospitals and in 1995 departments of family practice will be funded in universities, too. In this article, we review the problems of family practice in Turkey and we mention our own opinions and comments about various aspects of it.

The effects of slow-release verapamil on blood pressure and cardiovascular system in essential hypertension.

The study consisted of 26 patients (15 female, 11 male; mean age 43 +/- 10 years) with mild to moderate essential hypertension (EH). They were followed for a 2-week washout period and then for another 2-week single-blind placebo phase. Four patients receiving placebo dropped out of the study. Patients qualified for active medication if their sitting diastolic blood pressures (BPs), the median of three readings, were between 95 and 115 mm Hg at the end of the placebo period. Slow-release verapamil 240 mg was given once or twice daily as the sole antihypertensive agent and was continued for 6 weeks. Two patients (9%) were excluded from the trial due to early side effects. A target diastolic BP of less than 90 mm Hg was obtained in the remaining 20 patients. At the end of the study, the mean value of sitting BP was reduced from an initial 170/103 (125) mm Hg to 130/81 (98) mm Hg (p less than 0.001) and the mean standing BP was decreased from 167/103 (125) mm Hg to 130/81 (98) mm Hg (p less than 0.001). The drug had no significant effects on the laboratory data, left ventricular performance as assessed by echocardiography and systolic time intervals, and the electrocardiogram parameters with the exception of PR prolongation (p less than 0.05). Adverse effects were noted in only three patients (14%). We conclude that slow-release verapamil is an effective, safe, and well-tolerated drug in treating EH.

Acute systolic hypertension after acute myocardial infarction: prognostic and therapeutic significance.

In this study, the incidence of acute systolic hypertension (ASH) after acute myocardial infarction and the effects of this complication on the clinical course and prognosis of the disease were studied retrospectively in 950 cases. ASH was characterized as an elevation of systolic blood pressure over 170 mmHg for at least 30 minutes in a previously normotensive subject. There were 50 cases with ASH (5.3%) and 370 (38.9%) with normal blood pressures among the studied 950. The incidences of acute left ventricular failure and of arrhythmias such as sinus tachycardia, atrial and ventricular premature beats and ventricular tachycardia were significantly higher in the group with ASH in comparison with those with normal blood pressures. The group with ASH had also a greater average number of recurrent ventricular fibrillation attacks. The peak SGOT levels were found to be significantly increased in cases in whom the ASH sustained for more than 12 hours. The results suggested that the ASH which occurred predominantly in the early period of acute myocardial infarction was associated with more extensive myocardial damage resulting in a poor clinical course complicated by frequent ventricular arrhythmias and left ventricular failure. It is our conclusion that ASH after myocardial infraction is associated with relatively poor prognosis.

Prognostic significance of isolated left anterior hemiblock and left axis deviation in the course of acute myocardial infarction.

In 700 patients with acute myocardial infarction admitted to the intensive coronary care unit of our hospital, the incidence and significance of left anterior hemiblock and left axis deviation has been studied in the acute phase of disease. In 102 (14.6%) of the 700 patients, isolated left axis deviation (mean QRS axis-45 degrees) was found and 69 of them (9.9%) met the criteria of left anterior hemiblock. Of the 69 patients with left anterior hemiblock, 61 had acute anterior myocardial infarction, 5 had inferior infarction, and 3 had subendocardial infarction. The anterior hemiblock was transient in 5 patients, but persisted in 64. All patients with and without isolated left anterior hemiblock and left axis deviation were compared statistically with reference to mortality rate and the incidence of arrythmias; no significant difference was noted. However, in patients over the age of 65 and also in those with hypertension, the incidence of left axis deviation was significantly higher (P less than 0.05 and P less than 0.001, respectively). It was concluded that isolated left anterior hemiblock and left axis deviation occurring in the course of acute myocardial infarction no influence on the prognosis of acute myocardial infarction.