Antioxidant capacity in renal transplant patients.

The aim of the study was to analyse the relation between total antioxidant capacity and immunosuppressive therapies, renal function and hematocrit in kidney transplant patients. The study included 46 adult patients during the maintenance period (>1 year) following renal transplantation, treated with different combinations of immunosuppressive agents--most commonly with cyclosporine (n = 23) or tacrolimus (n = 15). The total antioxidant capacity (TAOC) of plasma was measured using Trolox-equivalent antioxidant capacity (TEAC) assay. Patients treated with cyclosporine had significantly greater TAOC compared with those treated with tacrolimus (1.16 +/- 0.46 mmol/L vs. 0.80 +/- 0.37 mmol/L, p = 0.018, respectively). There was a significantly negative correlation between TAOC and plasma creatinine (rs = -0.551, p = 0.033) and a positive correlation between TAOC and creatinine clearance or hematocrit in patients treated with tacrolimus but not with cyclosporine (r = 0.525, p = 0.045 or rs = 0.629, p = 0.012, respectively). Immunosuppressive therapy with cyclosporine was associated with higher TAOC. Anemia can be an independent risk factor for an increase of oxidative stress. Although subject numbers werelimited, TAOC was positively associated with renal function in patients treated with tacrolimus.

QT interval dispersion in ventricular beats: a noninvasive marker of susceptibility to sustained ventricular arrhythmias.

Increased QT dispersion (QTd) calculated from sinus beats has been shown to identify patients prone to sustained VT. However, predictive accuracy of this parameter is limited. Electrophysiological properties of the myocardium may be altered by a premature ventricular beats, which is a well-established trigger for sustained VT. Therefore, the author hypothesised that QTd in spontaneous or paced ventricular beats may improve identification of patients with inducible sustained VT. In 28 consecutive patients (men, mean age 61 +/- 13 years) who underwent programmed ventricular stimulation, the values of QTd calculated in sinus and ventricular beats were compared between inducible and noninducible patients. The mean QTd values obtained using three different methods differed significantly, QTd in paced ventricular beats being the highest, QTd in spontaneous ventricular beats was intermediate, and QTd in sinus beats was the lowest (83.9 +/- 30 vs 63.0 +/- 29 ms vs 53.9 +/- 27 ms, P < 0.0001 and P < 0.004, respectively). In 13 (46%) patients sustained VT was induced. QTd values were significantly higher in inducible than noninducible patients (QTd sinus beats: 67.5 +/- 31 vs 42.1 +/- 11 ms, P = 0.02; QTd spontaneous ventricular beats: 79.3 +/- 35 vs 46.7 +/- 13 ms, P = 0.008, and QTd-paced ventricular beats: 104.8 +/- 32 vs 65.9 +/- 9 ms, P = 0.0009). The receiver operator characteristic curves showed that at a sensitivity level of 100%, the highest specificity for identification of inducible patients had QTd measured in paced ventricular beats (87%) followed by QTd in spontaneous ventricular beats (45%), and QTd in sinus beats (40%). In conclusion, (1) QTd in ventricular beats is greater than in sinus beats, and (2) QTd calculated from paced ventricular beats identifies patients with inducible sustained VT better than QTd measured during sinus rhythm.

Hypomagnesemia in heart failure with ventricular arrhythmias. Beneficial effects of magnesium supplementation.

OBJECTIVE: To assess the role of electrolyte imbalance in cardiac arrhythmias associated with congestive heart failure. DESIGN: Serum magnesium and potassium levels, urine magnesium excretion and the incidence of ventricular arrhythmias were assessed throughout the study. The patients who displayed complex arrhythmias after the first week of hospital medication were randomized 2:1 to double-blind magnesium supplementation or placebo. SETTING: The study was carried out in one municipal hospital, providing primary care. SUBJECTS: A total of 588 consecutive patients were screened for eligibility (clinical heart failure >/=6 months; NYHA class II-IV; left ventricular ejection fraction

Intravenous amiodarone is safe and seems to be effective in termination of paroxysmal supraventricular tachyarrhythmias.

BACKGROUND: Paroxysmal atrial fibrillation (PAF) and paroxysmal supraventricular tachycardia (PSVT) leading to hemodynamic compromise are among the most common reasons for admission to the coronary care unit (CCU) and need prompt and efficient therapy. Direct current cardioversion is the therapy of choice, but if found contraindicated or unavailable some antiarrhythmic agents are usually given to restore sinus rhythm. Many of these drugs have obvious limitations, especially in patients with acute myocardial infarction and/or heart failure. HYPOTHESIS: The aim of the present study was to assess the safety and efficacy of intravenous amiodarone in the acute termination of PAF or PSVT refractory to other antiarrhythmic agents in a large group of patients consecutively admitted to our CCU. METHODS: In the present study, we evaluated the safety and efficacy of amiodarone given intravenously in 142 consecutive patients with PAF or PSVT lasting < 24 h. In 37% of patients no evidence of underlying heart disease which may have caused arrhythmias were defined. A median of two other antiarrhythmic agents given prior to the first amiodarone injection had been ineffective. RESULTS: Sinus rhythm was restored in 91 patients (64%) (65% in the PAF group and 61% in the PSVT group). The mean time to rhythm conversion was 5.5 +/- 6.1 h for patients with PAF and 1.2 +/- 1.2 h for patients with PSVT. The mean dose of amiodarone administered up to conversion was 340 +/- 220 mg for PAF and 220 +/- 105 mg for PSVT. Except for transient first-degree atrioventricular block in two patients, no adverse effects possibly related to amiodarone were observed (including proarrhythmia and incidence or aggravation of heart failure symptoms). CONCLUSION: Amiodarone given intravenously for acute termination of supraventricular tachyarrhythmias is completely safe and seems effective. The results of this study, which is the largest ever made, indicate a need of randomized, controlled trials for the ultimate assessment of the efficacy of amiodarone in this clinical setting.

The incidence of asymptomatic paroxysmal atrial fibrillation in patients treated with propranolol or propafenone.

Anti-arrhythmic therapy for paroxysmal atrial fibrillation leads to complete symptomatic relief in a number of patients. The elimination of symptoms may be associated either with a complete elimination of arrhythmia or with a conversion of symptomatic atrial fibrillation into asymptomatic episodes of arrhythmia. The aim of the study was to evaluate the occurrence of asymptomatic paroxysmal atrial fibrillation in 52 patients treated with propafenone (35 drug trials) or propranolol (34 drug trials) by means of ambulatory ECG Holter monitoring. Propafenone was clinically effective (complete relief of symptoms) in 26 (74%) patients. However, in 7 cases (27%) asymptomatic episodes of arrhythmia were still recorded when awake. In patients treated with propranolol clinical symptoms were absent in 18 (53%). However, in 4 (22%) patients attacks of paroxysmal atrial fibrillation were present. The mechanism of drug-induced conversion of symptomatic episodes of atrial fibrillation into asymptomatic spells of arrhythmia was a marked shortening in duration of episodes in 7 patients (from 2215 +/- 3843 s to 16 +/- 10 s, N.S.) or by a significant slowing of ventricular response during atrial fibrillation in 4 patients (from 125 +/- 27 to 84 +/- 8 beats/min, P = 0.05). In conclusion, in a significant proportion of patients with symptomatic paroxysmal atrial fibrillation asymptomatic episodes of arrhythmia may occur while on anti-arrhythmic drug therapy. Some of these patients, particularly those with other risk factors for stroke such as advanced age or the presence of organic heart disease, may require anti-coagulant therapy or change in anti-arrhythmic treatment, and can be selected on the basis of ambulatory ECG monitoring.

[The effect of work-related stress on the occurrence of increased blood pressure]. / Wplyw stresu zwiazanego z praca na wystepowanie podwyzonego cisnienia tetniczego krwi.

In 546 officials the arterial blood pressure was measured twice at the beginning and at the end of a working day, filling also an inquiry form. As hypertension systolic BP over 160 mm Hg (21.3 kPa) or more, and diastolic BP 96 mm Hg (12.7 kPa) or more were accepted. In 90 subjects (16.5%) above normal pressure values were found. Hypertension had been diagnosed previously in 50 subjects in this group (55.5%) but only 13 of them (26%) were treated systematically. Excessive stress of work was complained of by 62.6% of the subjects. Increased blood pressure was found significantly more frequently in the group perceiving excessive stress of work (19.9%) as compared to those not experiencing this stress (10.8%, p less than 0.1). In the group in managerial posts these proportions were 24.8% and 14.4% respectively (p less than 0.1). Blood pressure rise to abnormal levels during the working day occurred also significantly more frequently in the group experiencing it this was noted only in 1.6% of cases (p less than 0.5). The knowledge of own hypertension was very low in this group. These results indicate the necessity of increasing prophylactic measures in the form of greater frequency of control measurements of the blood pressure, better health education, and limitation of stress situations in working environment.