ß-Blocker Use and Risk of Mortality in Heart Failure Patients Initiating Maintenance Dialysis.

RATIONAL & OBJECTIVE: Beta-blockers are recommended for patients with heart failure (HF) but their benefit in the dialysis population is uncertain. Beta-blockers are heterogeneous, including with respect to their removal by hemodialysis. We sought to evaluate whether ß-blocker use and their dialyzability characteristics were associated with early mortality among patients with chronic kidney disease with HF who transitioned to dialysis. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Adults patients with chronic kidney disease (aged≥18 years) and HF who initiated either hemodialysis or peritoneal dialysis during January 1, 2007, to June 30, 2016, within an integrated health system were included. EXPOSURES: Patients were considered treated with ß-blockers if they had a quantity of drug dispensed covering the dialysis transition date. OUTCOMES: All-cause mortality within 6 months and 1 year or hospitalization within 6 months after transition to maintenance dialysis. ANALYTICAL APPROACH: Inverse probability of treatment weights using propensity scores was used to balance covariates between treatment groups. Cox proportional hazard analysis and logistic regression were used to investigate the association between ß-blocker use and study outcomes. RESULTS: 3,503 patients were included in the study. There were 2,115 (60.4%) patients using ß-blockers at transition. Compared with nonusers, the HR for all-cause mortality within 6 months was 0.79 (95% CI, 0.65-0.94) among users of any ß-blocker and 0.68 (95% CI, 0.53-0.88) among users of metoprolol at transition. There were no observed differences in all-cause or cardiovascular-related hospitalization. LIMITATIONS: The observational nature of our study could not fully account for residual confounding. CONCLUSIONS: Beta-blockers were associated with a lower rate of mortality among incident hemodialysis patients with HF. Similar associations were not observed for hospitalizations within the first 6 months following transition to dialysis.

Use of beta-blocker types and risk of incident prostate cancer in a multiethnic population.

PURPOSE: Increased adrenergic innervation is observed in prostate cancer (CaP) and is associated with aggressive disease. Emerging evidence suggests that beta-adrenergic blockade inhibits CaP progression. However, the association between type of beta-blocker use and risk of incident CaP on initial prostate biopsy has not been investigated in multiethnic populations. MATERIALS AND METHODS: A retrospective study of racially/ethnically diverse men (64% African-American and Hispanic), who underwent initial prostate biopsy between 2006 and 2016 in a large healthcare system was performed. Oral use of beta-blocker type was assessed by reviewing active prescriptions within the 5-year period preceding initial biopsy. Patient demographics and clinical factors were collected. RESULTS: Of 4,607 men who underwent initial prostate biopsy, 4,516 met criteria and 2,128 had a biopsy positive for CaP; 20% high-risk, 41% intermediate-risk, and 39% low or very-low risk (National Comprehensive Cancer Network classification). Overall, 15% of patients were taking a beta-blocker prior to initial biopsy, with Metoprolol, Atenolol, and Carvedilol accounting for the majority. Of beta-blocker types, Atenolol alone was associated with a 38% reduction in odds of incident CaP (P= 0.01), with a 40% and 54% reduction in risks of National Comprehensive Cancer Network intermediate and high-risk CaP (P = 0.03 and P = 0.03, respectively) compared to men not taking a beta-blocker. Furthermore, longer duration of Atenolol use (3-5 years) was associated with a 54% and 72% reduction in intermediate and high-risk disease, (P = 0.03 and P = 0.03, respectively). CONCLUSIONS: Among beta blocker types, long-term Atenolol use is associated with a significant reduction in incident CaP risk on initial prostate biopsy for clinically-significant intermediate and high-risk disease compared to men not taking a beta-blocker.

Comparative efficacy and safety of oral antihypertensive agents in pregnant women with chronic hypertension: a network metaanalysis.

OBJECTIVE DATA: Chronic hypertension is associated with adverse perinatal outcomes, although the optimal treatment is unclear. The aim of this network metaanalysis was to simultaneously compare the efficacy and safety of antihypertensive agents in pregnant women with chronic hypertension. STUDY: Medline, Scopus, CENTRAL, Web of Science, Clinicaltrials.gov, and Google Scholar databases were searched systematically from inception to December 15, 2019. Both randomized controlled trials and cohort studies were held eligible if they reported the effects of antihypertensive agents on perinatal outcomes among women with chronic hypertension. STUDY APPRAISAL AND SYNTHESIS METHODS: The primary outcomes were preeclampsia and small-for-gestational-age risk. A frequentist network metaanalytic random-effects model was fitted. The main analysis was based on randomized controlled trials. The credibility of evidence was assessed by taking into account within-study bias, across-studies bias, indirectness, imprecision, heterogeneity, and incoherence. RESULTS: Twenty-two studies (14 randomized controlled trials and 8 cohorts) were included, comprising 4464 women. Pooling of randomized controlled trials indicated that no agent significantly affected the incidence of preeclampsia. Atenolol was associated with significantly higher risk of small-for-gestational age compared with placebo (odds ratio, 26.00; 95% confidence interval, 2.61-259.29) and is ranked as the worst treatment (P-score=.98). The incidence of severe hypertension was significantly lower when nifedipine (odds ratio, 0.27; 95% confidence interval, 0.14-0.55), methyldopa (odds ratio, 0.31; 95% confidence interval, 0.17-0.56), ketanserin (odds ratio, 0.29; 95% confidence interval, 0.09-0.90), and pindolol (odds ratio, 0.17; 95% confidence interval, 0.05-0.55) were administered compared with no drug intake. The highest probability scores were calculated for furosemide (P-score=.86), amlodipine (P-score=.82), and placebo (P-score=.82). The use of nifedipine and methyldopa were associated with significantly lower placental abruption rates (odds ratio, 0.29 [95% confidence interval, 0.15-0.58] and 0.23 [95% confidence interval, 0.11-0.46], respectively). No significant differences were estimated for cesarean delivery, perinatal death, preterm birth, and gestational age at delivery. CONCLUSION: Atenolol was associated with a significantly increased risk for small-for-gestational-age infants. The incidence of severe hypertension was significantly lower when nifedipine and methyldopa were administered, although preeclampsia risk was similar among antihypertensive agents. Future large-scale trials should provide guidance about the choice of antihypertensive treatment and the goal blood pressure during pregnancy.

Taurine Ameliorates Thyroid Hypofunction and Renal Injury in L-NAME-Induced Hypertensive Rats.

There is a growing global interest in hypertension due to its associated complications including renal dysfunction in patients. The thyroid system reportedly regulates renal function in both animal and human. The present study investigated the therapeutic efficacy of taurine on renal and thyroid dysfunctions in hypertensive rats. Hypertension was induced by oral administration of nitric oxide synthase inhibitor, N-nitro L-arginine-methyl-ester (L-NAME), at 40 mg/kg body weight to the male Wistar rats for 14 consecutive days. The hypertensive rats were subsequently treated with either taurine (100 and 200 mg/kg) or reference drug atenolol (10 mg/kg) for another 14 consecutive days. Hypertensive rats showed renal damage evidenced by elevated plasma creatinine and urea levels when compared with normotensive control rats. Furthermore, L-NAME-induced hypertensive rats showed decreased circulatory concentrations of thyroid stimulating hormone, thyroxine, triiodothyronine and the ratio of triiodothyronine to thyroxine. The marked decrease in the renal antioxidant enzyme activities and nitric oxide level was accompanied by significant increase in myeloperoxidase activity and biomarkers of oxidative stress in hypertensive rats. Histological examination of kidneys from hypertensive rats revealed congestion of blood vessels, hemorrhagic lesion and disorganized glomerular structure. However, treatment with taurine or atenolol significantly reversed the suppression of thyroid function, ameliorated renal oxidative stress and histopathological lesions in L-NAME-induced hypertensive rats. Taurine may be a useful chemotherapeutic supplement in enhancing renal and thyroid functions in hypertensive patients.

Idiopathic aquagenic pruritus: pathogenesis and effective treatment with atenolol.

Aquagenic pruritus (AP) is a rare condition with unknown pathogenesis. We explored its pathogenesis through investigations of a patient and report the first case to be effectively treated with atenolol. A 36-year-old Indian female presented with idiopathic AP. Small-fiber neuropathy involving itch/pain-transmitting C-fibers appears to be pathogenetically important: compared with matched controls, our patient had increased intra-epidermal nerve fibers, raised warmth detection threshold, and marked hyperknesis to electrical stimulation. Autonomic nerve function tests and fingertips vasoconstriction response were normal, indicating integrity of other small (Aδ and C) nerve fibers. She was initially treated with propranolol with good response, but was subsequently switched to atenolol for convenient once-a-day dosing. Symptoms were well controlled long term with no side effect experienced. Atenolol may exert its effect in AP through blockage of over-activated neuronal sodium channels. Through the investigations, we propose that the pathogenesis of idiopathic AP may involve the following: upon contact of the skin with water, yet-unknown mediator/s released stimulate dysfunctional and hyper-innervated C-nerve fibers, which may have resulted from a sodium channel defect. Atenolol may be a preferred therapeutic option compared with propanolol, in view of its convenient once-a-day dosing and better side effect profile.

La suplementación de larga duración con atenolol convierte la insaturación de las membranas mitocondriales de músculo esquelético y de corazón de ratón en la característica de mamíferos de supervivencia diez veces mayor. Efectos sobre la longevidad media y máxima / Long-life supplementation with atenolol converts the heart and skeletal muscle unsaturation of mitochondrial membranes of mice into those of ten fold longer-lived mammals. Effects on mean and maximum longevity

Se estudia por primera vez el efecto a largo plazo del atenolol en el agua de bebida durante toda la vida (3,3 años) de un mamífero (128 ratones C57BL/6 macho-SPF). Observamos cambios beneficiosos relacionados con el envejecimiento: descenso en el grado de insaturación de las membranas mitocondriales y del ácido graso 22:6n-3, un incremento del ácido oleico, y descenso de la oxidación, glicoxidación y lipoxidación de proteínas y daño oxidativo al ADNmt en mitocondrias de corazón y músculo esquelético. Sin embargo, detectamos un efecto secundario del fármaco sólo en animales viejos que coincide con meta-análisis recientes en pacientes humanos (AU)

The long-term effects of atenolol in drinking water throughout the whole lifespan (3.3 years) of a mammal (128 C57BL/6 male mice-SPF) were studied for the first time. We observed beneficial aging-related changes: decreases in the degree of unsaturation of mitochondrial membranes and of the 22:6n-3 fatty acid, an increase in oleic acid, as well as decreases in protein oxidation, glycoxidation and lipoxidation and oxidative damage in mtDNA in heart and skeletal muscle mitochondria. However, a secondary effect of the drug only in old animals was detected that agrees with recent meta-analyses in human patients (AU)

Effect of metformin on weight gain during antihypertensive treatment with a beta-blocker in Chinese patients.

BACKGROUND: Overweight and obesity are associated with cardiovascular disease (CVD). This study was designed to investigate whether combined use of nitrendipine and atenolol has any effect on body weight (BW) and whether metformin can prevent antihypertensive medication-induced weight gain and has any effect on blood glucose (BG). METHODS: Included in the present study were 94 hypertensive patients with a body mass index (BMI) > or =25 kg/m(2), of whom 45 patients were treated with nitrendipine plus atenolol (N/A group), and the remaining 49 patients were treated with nitrendipine, atenolol, and metformin (N/A/M group). The mean follow-up duration was 14 months. BW and glucose tolerance were measured. RESULTS: In N/A group, BW and fasting BG significantly increased from 73.5 +/- 9.6 kg to 74.2 +/- 9.7 kg (P < 0.05) and from 94.2 +/- 10.5 mg/dl to 97.9 +/- 11.3 mg/dl (P < 0.01), respectively, whereas postprandial BG did not change significantly. In N/A/M group, BW slightly decreased from 72.7 +/- 10.1 kg to 72.3 +/- 10.2 kg (P = 0.30), and fasting BG did not change significantly (93.5 +/- 10.4 mg/dl vs. 92.7 +/- 10.2 mg/dl, P = 0.59), whereas 2-h postprandial BG significantly decreased from 133.7 +/- 30.5 mg/dl to 124.0 +/- 29.6 mg/dl (P < 0.05). Furthermore, a significant difference was observed in difference value of BW before and after treatment between the two groups (0.7 (95% confidence interval, 0.1-1.3) kg in N/A group vs. -0.4 (95% confidence interval, -1.3 to 0.4) kg in N/A/M group, P < 0.05). CONCLUSIONS: Combination therapy of nitrendipine and atenolol may significantly increase BW and fasting BG in overweight or obese patients with hypertension. Metformin may prevent BW gain and improve BG levels in hypertensive patients who received combination therapy of nitrendipine and atenolol.

Comparison of hypotensive and hypolipidemic effects of Catharanthus roseus leaves extract with atenolol on adrenaline induced hypertensive rats.

The leaves extract of Catharanthus roseus was investigated for hypotensive and hypolipidemic effects in adrenaline-induced hypertensive rats (AIHR) and compared with those of Atenolol in a crossover design. The pharmacologically Active components responsible for hypotensive activities were isolated from plant using bioassay guided purification approach and the structure of the compounds was proposed by spectroscopic methods. Catharanthus roseus leaves extract and commercial drug Atenolol were administered through intraperitoneal (i.p) route for one week. Different biochemical parameters such as heart weight, blood glucose level, serum cholesterol level, serum triglyceride level, body weight and the relationships between them were measured. Catharanthus roseus leaves extract at a dose of 30 mg/155+/-15 gm of body weight was injected in rat at every morning during the treatment period. The dose of Atenolol was determined according to its pharmacokinetic parameters. Clinically effective plasma concentration as a hypotensive drug was obtained after the injection of 0.1 mg/155+/-15 gm of body weight of the drug. The Catharanthus roseus leaves extract made significant changes in each cardiovascular parameter after investigation. Catharanthus roseus leaves extract treated animals have shown the hypotensive effects. Hypotensive effects were also shown by Atenolol.

Impact of beta-blocker treatment and nutritional status on glycemic response during exercise in patients with type 2 diabetes.

PURPOSE: Most individuals with type 2 diabetes are affected by hypertension and thus have higher risk of cardiac complications. In addition to behavioural modifications, such as healthy food choices and regular physical activity, beta-blocker treatment may be considered to reduce morbidity and mortality, especially after a cardiovascular event. However, this medication is generally associated with a deleterious impact on glucose metabolism. The objective of the study was to assess the impact of beta-blocker treatment on glucose response during exercise in patients with type 2 diabetes, free of cardiovascular complications. METHODS: Ten sedentary men, treated with diet and/or hypoglycemic agents have performed four exercise sessions at 60% of their V O2peak, in the fasted state or 2 hours following a standardized breakfast, with and without beta-blockers (atenolol 100 mg id for five consecutive days). Blood samples were drawn during the resting period, at 15-min intervals during the exercise session and during the recovery period. RESULTS: A reduction of blood glucose levels was observed following the exercise session in the postprandial state (48% and 44% reduction with and without beta-blockers respectively; P < 0.001). One hour of exercise performed in the fasted state had a minimal impact on glucose and insulin levels, whether with or without beta-blockers. beta-blocker treatment was not associated with increased baseline blood glucose or insulin levels in the fasted or the postprandial situation. CONCLUSION: Dietary status has a more important impact on plasma glucose and insulin modulation than short-term use of beta-blockers.

A pilot study of open label sesame oil in hypertensive diabetics.

The objective of this study was to investigate the effect of sesame oil in hypertensive diabetics medicated with atenolol (beta-blocker) and glibenclamide (sulfonylurea). This open label trial with two intervention periods comprised 22 male and 18 female patients, 45-65 years old, with mild to moderate hypertension and diabetes. Sesame oil (Idhayam Gingelly oil, V.V.V. & Sons, Virudhunagar, Tamilnadu, India) was supplied to the patients, who were instructed to use it in place of other cooking oils for 45 days. Blood pressure (BP), anthropometric measurements, plasma glucose, glycated hemoglobin (HbA1c), lipid profiles [total cholesterol, low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol, and triglycerides (TG)], lipid peroxidation [thiobarbituric acid-reactive substances (TBARS)], electrolytes (sodium, potassium, and chloride), and enzymic (superoxide dismutase, glutathione peroxidase, and catalase) and nonenzymic (vitamin C, vitamin E, beta-carotene, and reduced glutathione) antioxidants were measured at baseline and after 45 days of sesame oil substitution. The same patients were then switched over to other oils like palm or groundnut oils as their regular oils at random for another 45 days, and the investigations were carried out again at the end. Systolic and diastolic BP decreased remarkably. When oil substitution was withdrawn, BP values rose again. Body weight, body mass index, girth of waist, girth of hip, and waist:hip ratio were reduced upon substitution of sesame oil. Plasma glucose, HbA1c, TC, LDL-C, and TG were decreased. TBARS level was reduced, while the activities of enzymic and the levels of nonenzymic antioxidants were increased. Plasma sodium levels were reduced, while potassium levels were elevated. These results indicate that substitution of sesame oil as the sole edible oil has an additive effect in further lowering BP and plasma glucose in hypertensive diabetics.

Blood pressure variability, baroreflex sensitivity and organ damage in spontaneously hypertensive rats treated with various antihypertensive drugs.

Besides blood pressure, blood pressure variability and baroreflex sensitivity maybe important factors determining organ damage in hypertension. This study was designed to investigate the effects of various antihypertensive drugs on blood pressure and blood pressure variability reductions, baroreflex sensitivity, and target organ damage in spontaneously hypertensive rats (SHR). The dose is 20 mg/kg/day for atenolol, and 10 mg/kg/day for nifedipine, irbesartan and hydrochlorothiazide. We used relatively low doses of drugs to avoid a very remarkable normalization of blood pressure in the treatment, which would make it much difficult to distinguish the contribution of blood pressure variability and baroreflex sensitivity to organ protection from that of blood pressure. Drugs at the aforementioned doses were mixed into rat chow. SHR were treated for 4 months. Blood pressure was then continuously recorded for 24 h. After the determination of baroreflex sensitivity, rats were killed for organ-damage evaluation. It was found that long-term treatment with atenolol, nifedipine, irbesartan or hydrochlorothiazide all markedly reduced blood pressure variability, enhanced baroreflex sensitivity, and produced significant organ protection. Compared with blood pressure level, blood pressure variability and baroreflex sensitivity values showed a much closer or similar relationship with organ-damage parameters in every treatment group of rats. Multiple-regression analysis showed that the decrease in left ventricular hypertrophy, the decrease in aortic hypertrophy and the amelioration in renal lesion were all most closely correlated with the increase in baroreflex sensitivity and the decrease in systolic blood pressure variability. In conclusion, long-term treatment with atenolol, nifedipine, irbesartan or hydrochlorothiazide produced organ protection in SHR. Besides the blood pressure reduction, the decrease in blood pressure variability and the restoration of baroreflex sensitivity may contribute to this organ protection.

Extract of Lycopus europaeus L. reduces cardiac signs of hyperthyroidism in rats.

Extracts from the plant Lycopus europaeus L. are traditionally used in mild forms of hyperthyroidism. High doses caused a reduction of TSH or thyroid hormone levels in animal experiments, whereas in hyperthyroid patients treated with low doses of Lycopus an improvement of cardiac symptoms was reported without major changes in TSH or thyroid hormone concentrations. Lycopus extract was tested in thyroxine treated hyperthyroid rats (0.7 mg/kg BW i.p.). Co-treatment with an hydroethanolic extract from L. europaeus L. started one week later than T4-application and lasted 5.5 weeks. As reference substance atenolol was used. The raised body temperature was reduced very effectively even by the low dose of the plant extract, whereas the reduced gain of body weight and the increased food intake remained unaffected by any treatment. No significant changes of thyroid hormone concentrations or TSH levels were observed. Lycopus extract and atenolol reduced the increased heart rate and blood pressure. The cardiac hypertrophy was alleviated significantly by both treatment regimes. beta-Adrenoceptor density in heart tissue was significantly reduced by the Lycopus extract or the beta-blocking agent showing an almost equal efficacy. Although the mode of action remains unclear, these organo-specific anti-T4-effects seem to be of practical interest, for example in patients with latent hyperthyroidism.

The role of the new beta-blockers in treating cardiovascular disease.

The beta-adrenergic receptor blockers play an important role in the management of cardiovascular disease, including hypertension and chronic heart failure. However, concerns regarding safety and tolerability with currently available agents can limit their use. The beta-blockers vary with regard to several pharmacologic properties, including beta1/beta2 selectivity, intrinsic sympathomimetic activity, and, with the newest beta-blockers, vasodilation. These pharmacologic differences may result in clinically important differences in tolerability and hemodynamic properties. Nebivolol is a novel beta-blocker with both a greater degree of selectivity for beta1-adrenergic receptors than other agents in this class and an ability to stimulate endothelial nitric oxide production, leading to vasodilation and other potential clinical effects. Published randomized, controlled, multicenter studies with nebivolol have shown that once-daily treatment significantly reduces systolic and diastolic blood pressure in patients with mild-to-moderate hypertension, compared with placebo, in a dose-dependent manner, and is well tolerated, with an adverse event profile similar to that of placebo. When compared with other beta-blockers as well as with other antihypertensive classes of agents in head-to-head trials, nebivolol demonstrated similar antihypertensive efficacy and a lower incidence of adverse events. Nebivolol has also been shown to significantly reduce morbidity and mortality in a large population of elderly patients with chronic heart failure, independent of left ventricular ejection fraction. Nebivolol is currently available in Europe for the management of hypertension and is expected to be available soon in the United States.

Long QT syndrome: anaesthetic management at delivery.

We describe the anaesthetic management of a spontaneous vaginal delivery at 39 weeks' gestation in a 22-year-old patient with congenital long QT syndrome. With a strong family history of sudden deaths, the patient had an initial QT interval corrected for rate (QTc) of >600 ms. Following a once-daily 50-mg dose of atenolol over the previous 11 months, her QTc remained prolonged at 560 ms. To minimise any increase in catecholamine levels and consequent risk of malignant ventricular arrhythmias, a combined spinal-epidural technique was selected using intrathecal diamorphine and levobupivacaine, with intravenous and oral magnesium and potassium supplementation. Levobupivacaine was substituted for routine racemic bupivacaine to decrease the risk of drug-induced cardiotoxicity. Delivery outcome was successful and uneventful. We outline the pathophysiology, risks and treatments of long QT syndrome, and discuss the analgesic management of this patient in labour with congenital long QT syndrome.

[The effect of antihypertensive drugs on the anaesthetic effect of lidocaine in hypertensive patients who need dental treatment]. / Influenta unor medicamente antihipertensive asupra efectului anestezic al lidocainei la pacientii hipertensivi care necesita terapie stomatologica.

The study evaluated the influence of atenolol/nifedipine on the local anaesthesia with lidocaine in 64 patients with essential arterial hypertension following dietetic regimen and divided in: control group (21 patients), atenolol-treated group (21 patients with atenolol therapy) and nifedipine-treated group (22 patients with nifedipine therapy). Atenolol/nifedipine was administrated three hours before anaesthesia (1.5 mg lidocaine/kg body weight) applied on Spix Spina. The atenolol/nifedipine influence on the anaesthetic intensity was evaluated both by the patient and dentist using scales for the appreciation of pain intensity (Visual Analogue Scale, Numerical Rating Scale) at 0 minutes (before anaesthesia), 5, 10, 20, 30, 60 minutes (moments for the determination of lidocaine plasmatic concentrations). There were no statistically significant differences between the values appreciated by the patient and dentist. Our data demonstrated a significant decrease of pain intensity in patients treated with atenolol/nifedipine. Very good inverse correlation was found between lidocaine concentrations and pain intensity.

Long-term efficacy of atenolol for atrioventricular reciprocating tachycardia in children less than 5 years old.

Atrioventricular reciprocating tachycardia (AVRT) using an accessory pathway is the most common supraventricular tachycardia observed in infancy and childhood. There is a general agreement to treat children older than 5 years who are on a potentially long-term antiarrhythmic agent with radiofrequency catheter ablation. Atenolol, a relatively long-acting and cardioselective beta-adrenoceptor blocker, has been used to control the various types of supraventricular tachycardia in children and adults. There are few reports on the use of atenolol in children <5 years old with AVRT. This retrospective study reports our experience in 22 children <5 years old (median age, 20 months) who received atenolol monotherapy between 1995 and 2001 for treatment of AVRT. AVRT was confirmed in 17 patients by transvenous or transesophageal electrophysiologic study and in 5 patients by documented preexcitation on electrocardiograms. In nine patients atenolol was the first antiarrhythmic drug given. In 15 of the 22 patients (68%) therapy with atenolol was considered successful. The average effective dose of atenolol in these 15 patients was 1.2 +/- 0.3 mg/kg/day. During a median follow-up of 41 months (8-74 months), atenolol had been discontinued in 10 patients and no further attacks of tachycardia occurred except in 1 patient. In no case did the drug have to be withdrawn for adverse effects. In conclusion, this retrospective study shows that atenolol as a monotherapy is efficient and relatively safe in the long-term treatment of AVRT in young children. Atenolol can be recommended as a first-line treatment option for the management of AVRT in infants and young children.